Documentation

Documentation

Includes

config.h

#include "config.h"
#include "config.h"

MBEDTLS_CONFIG_FILE

#include MBEDTLS_CONFIG_FILE
#include MBEDTLS_CONFIG_FILE

bignum.h

#include "bignum.h"
#include "bignum.h"

ecp.h

#include "ecp.h"
#include "ecp.h"

ssl_ciphersuites.h

#include "ssl_ciphersuites.h"
#include "ssl_ciphersuites.h"

x509_crt.h

#include "x509_crt.h"
#include "x509_crt.h"

x509_crl.h

#include "x509_crl.h"
#include "x509_crl.h"

dhm.h

#include "dhm.h"
#include "dhm.h"

ecdh.h

#include "ecdh.h"
#include "ecdh.h"

zlib.h

#include "zlib.h"
#include "zlib.h"

platform_time.h

#include "platform_time.h"
#include "platform_time.h"

Macros

Marco MBEDTLS_SSL_H

#define MBEDTLS_SSL_H


      

Marco MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE

#define MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE              -28800 /**< The requested feature is not available. */
/*
 * SSL Error codes
 */

Marco MBEDTLS_ERR_SSL_BAD_INPUT_DATA

#define MBEDTLS_ERR_SSL_BAD_INPUT_DATA                   -28928 /**< Bad input parameters to function. */


      

Marco MBEDTLS_ERR_SSL_INVALID_MAC

#define MBEDTLS_ERR_SSL_INVALID_MAC                      -29056 /**< Verification of the message MAC failed. */


      

Marco MBEDTLS_ERR_SSL_INVALID_RECORD

#define MBEDTLS_ERR_SSL_INVALID_RECORD                   -29184 /**< An invalid SSL record was received. */


      

Marco MBEDTLS_ERR_SSL_CONN_EOF

#define MBEDTLS_ERR_SSL_CONN_EOF                         -29312 /**< The connection indicated an EOF. */


      

Marco MBEDTLS_ERR_SSL_UNKNOWN_CIPHER

#define MBEDTLS_ERR_SSL_UNKNOWN_CIPHER                   -29440 /**< An unknown cipher was received. */


      

Marco MBEDTLS_ERR_SSL_NO_CIPHER_CHOSEN

#define MBEDTLS_ERR_SSL_NO_CIPHER_CHOSEN                 -29568 /**< The server has no ciphersuites in common with the client. */


      

Marco MBEDTLS_ERR_SSL_NO_RNG

#define MBEDTLS_ERR_SSL_NO_RNG                           -29696 /**< No RNG was provided to the SSL module. */


      

Marco MBEDTLS_ERR_SSL_NO_CLIENT_CERTIFICATE

#define MBEDTLS_ERR_SSL_NO_CLIENT_CERTIFICATE            -29824 /**< No client certification received from the client, but required by the authentication mode. */


      

Marco MBEDTLS_ERR_SSL_CERTIFICATE_TOO_LARGE

#define MBEDTLS_ERR_SSL_CERTIFICATE_TOO_LARGE            -29952 /**< Our own certificate(s) is/are too large to send in an SSL message. */


      

Marco MBEDTLS_ERR_SSL_CERTIFICATE_REQUIRED

#define MBEDTLS_ERR_SSL_CERTIFICATE_REQUIRED             -30080 /**< The own certificate is not set, but needed by the server. */


      

Marco MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED

#define MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED             -30208 /**< The own private key or pre-shared key is not set, but needed. */


      

Marco MBEDTLS_ERR_SSL_CA_CHAIN_REQUIRED

#define MBEDTLS_ERR_SSL_CA_CHAIN_REQUIRED                -30336 /**< No CA Chain is set, but required to operate. */


      

Marco MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE

#define MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE               -30464 /**< An unexpected message was received from our peer. */


      

Marco MBEDTLS_ERR_SSL_FATAL_ALERT_MESSAGE

#define MBEDTLS_ERR_SSL_FATAL_ALERT_MESSAGE              -30592 /**< A fatal alert message was received from our peer. */


      

Marco MBEDTLS_ERR_SSL_PEER_VERIFY_FAILED

#define MBEDTLS_ERR_SSL_PEER_VERIFY_FAILED               -30720 /**< Verification of our peer failed. */


      

Marco MBEDTLS_ERR_SSL_PEER_CLOSE_NOTIFY

#define MBEDTLS_ERR_SSL_PEER_CLOSE_NOTIFY                -30848 /**< The peer notified us that the connection is going to be closed. */


      

Marco MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO

#define MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO              -30976 /**< Processing of the ClientHello handshake message failed. */


      

Marco MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO

#define MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO              -31104 /**< Processing of the ServerHello handshake message failed. */


      

Marco MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE

#define MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE               -7A00 /**< Processing of the Certificate handshake message failed. */


      

Marco MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_REQUEST

#define MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_REQUEST       -7A80 /**< Processing of the CertificateRequest handshake message failed. */


      

Marco MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE

#define MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE       -7B00 /**< Processing of the ServerKeyExchange handshake message failed. */


      

Marco MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO_DONE

#define MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO_DONE         -7B80 /**< Processing of the ServerHelloDone handshake message failed. */


      

Marco MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE

#define MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE       -7C00 /**< Processing of the ClientKeyExchange handshake message failed. */


      

Marco MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE_RP

#define MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE_RP    -7C80 /**< Processing of the ClientKeyExchange handshake message failed in DHM / ECDH Read Public. */


      

Marco MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE_CS

#define MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE_CS    -7D00 /**< Processing of the ClientKeyExchange handshake message failed in DHM / ECDH Calculate Secret. */


      

Marco MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY

#define MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY        -7D80 /**< Processing of the CertificateVerify handshake message failed. */


      

Marco MBEDTLS_ERR_SSL_BAD_HS_CHANGE_CIPHER_SPEC

#define MBEDTLS_ERR_SSL_BAD_HS_CHANGE_CIPHER_SPEC        -7E00 /**< Processing of the ChangeCipherSpec handshake message failed. */


      

Marco MBEDTLS_ERR_SSL_BAD_HS_FINISHED

#define MBEDTLS_ERR_SSL_BAD_HS_FINISHED                  -7E80 /**< Processing of the Finished handshake message failed. */


      

Marco MBEDTLS_ERR_SSL_ALLOC_FAILED

#define MBEDTLS_ERR_SSL_ALLOC_FAILED                     -32512 /**< Memory allocation failed */


      

Marco MBEDTLS_ERR_SSL_HW_ACCEL_FAILED

#define MBEDTLS_ERR_SSL_HW_ACCEL_FAILED                  -32640 /**< Hardware acceleration function returned with error */


      

Marco MBEDTLS_ERR_SSL_HW_ACCEL_FALLTHROUGH

#define MBEDTLS_ERR_SSL_HW_ACCEL_FALLTHROUGH             -28544 /**< Hardware acceleration function skipped / left alone data */


      

Marco MBEDTLS_ERR_SSL_COMPRESSION_FAILED

#define MBEDTLS_ERR_SSL_COMPRESSION_FAILED               -28416 /**< Processing of the compression / decompression failed */


      

Marco MBEDTLS_ERR_SSL_BAD_HS_PROTOCOL_VERSION

#define MBEDTLS_ERR_SSL_BAD_HS_PROTOCOL_VERSION          -6E80 /**< Handshake protocol not within min/max boundaries */


      

Marco MBEDTLS_ERR_SSL_BAD_HS_NEW_SESSION_TICKET

#define MBEDTLS_ERR_SSL_BAD_HS_NEW_SESSION_TICKET        -6E00 /**< Processing of the NewSessionTicket handshake message failed. */


      

Marco MBEDTLS_ERR_SSL_SESSION_TICKET_EXPIRED

#define MBEDTLS_ERR_SSL_SESSION_TICKET_EXPIRED           -6D80 /**< Session ticket has expired. */


      

Marco MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH

#define MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH                 -6D00 /**< Public key type mismatch (eg, asked for RSA key exchange and presented EC key) */


      

Marco MBEDTLS_ERR_SSL_UNKNOWN_IDENTITY

#define MBEDTLS_ERR_SSL_UNKNOWN_IDENTITY                 -6C80 /**< Unknown identity received (eg, PSK identity) */


      

Marco MBEDTLS_ERR_SSL_INTERNAL_ERROR

#define MBEDTLS_ERR_SSL_INTERNAL_ERROR                   -6C00 /**< Internal error (eg, unexpected failure in lower-level module) */


      

Marco MBEDTLS_ERR_SSL_COUNTER_WRAPPING

#define MBEDTLS_ERR_SSL_COUNTER_WRAPPING                 -6B80 /**< A counter would wrap (eg, too many messages exchanged). */


      

Marco MBEDTLS_ERR_SSL_WAITING_SERVER_HELLO_RENEGO

#define MBEDTLS_ERR_SSL_WAITING_SERVER_HELLO_RENEGO      -6B00 /**< Unexpected message at ServerHello in renegotiation. */


      

Marco MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED

#define MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED            -6A80 /**< DTLS client must retry for hello verification */


      

Marco MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL

#define MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL                 -6A00 /**< A buffer is too small to receive or write a message */


      

Marco MBEDTLS_ERR_SSL_NO_USABLE_CIPHERSUITE

#define MBEDTLS_ERR_SSL_NO_USABLE_CIPHERSUITE            -27008 /**< None of the common ciphersuites is usable (eg, no suitable certificate, see debug messages). */


      

Marco MBEDTLS_ERR_SSL_WANT_READ

#define MBEDTLS_ERR_SSL_WANT_READ                        -26880 /**< No data of requested type currently available on underlying transport. */


      

Marco MBEDTLS_ERR_SSL_WANT_WRITE

#define MBEDTLS_ERR_SSL_WANT_WRITE                       -26752 /**< Connection requires a write call. */


      

Marco MBEDTLS_ERR_SSL_TIMEOUT

#define MBEDTLS_ERR_SSL_TIMEOUT                          -26624 /**< The operation timed out. */


      

Marco MBEDTLS_ERR_SSL_CLIENT_RECONNECT

#define MBEDTLS_ERR_SSL_CLIENT_RECONNECT                 -26496 /**< The client initiated a reconnect from the same port. */


      

Marco MBEDTLS_ERR_SSL_UNEXPECTED_RECORD

#define MBEDTLS_ERR_SSL_UNEXPECTED_RECORD                -26368 /**< Record header looks valid but is not expected. */


      

Marco MBEDTLS_ERR_SSL_NON_FATAL

#define MBEDTLS_ERR_SSL_NON_FATAL                        -26240 /**< The alert message received indicates a non-fatal error. */


      

Marco MBEDTLS_ERR_SSL_INVALID_VERIFY_HASH

#define MBEDTLS_ERR_SSL_INVALID_VERIFY_HASH              -26112 /**< Couldn't set the hash for verifying CertificateVerify */


      

Marco MBEDTLS_ERR_SSL_CONTINUE_PROCESSING

#define MBEDTLS_ERR_SSL_CONTINUE_PROCESSING              -25984 /**< Internal-only message signaling that further message-processing should be done */


      

Marco MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS

#define MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS                -25856 /**< The asynchronous operation is not completed yet. */


      

Marco MBEDTLS_ERR_SSL_EARLY_MESSAGE

#define MBEDTLS_ERR_SSL_EARLY_MESSAGE                    -25728 /**< Internal-only message signaling that a message arrived early. */


      

Marco MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS

#define MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS               -28672 /**< A cryptographic operation is in progress. Try again later. */


      

Marco MBEDTLS_ERR_SSL_QUIT_FORCED

#define MBEDTLS_ERR_SSL_QUIT_FORCED                      -22784


      

Marco MBEDTLS_SSL_MAJOR_VERSION_3

#define MBEDTLS_SSL_MAJOR_VERSION_3            3
/*
 * Various constants
 */

Marco MBEDTLS_SSL_MINOR_VERSION_0

#define MBEDTLS_SSL_MINOR_VERSION_0            0  /*!< SSL v3.0 */


      

Marco MBEDTLS_SSL_MINOR_VERSION_1

#define MBEDTLS_SSL_MINOR_VERSION_1            1  /*!< TLS v1.0 */


      

Marco MBEDTLS_SSL_MINOR_VERSION_2

#define MBEDTLS_SSL_MINOR_VERSION_2            2  /*!< TLS v1.1 */


      

Marco MBEDTLS_SSL_MINOR_VERSION_3

#define MBEDTLS_SSL_MINOR_VERSION_3            3  /*!< TLS v1.2 */


      

Marco MBEDTLS_SSL_TRANSPORT_STREAM

#define MBEDTLS_SSL_TRANSPORT_STREAM           0  /*!< TLS      */


      

Marco MBEDTLS_SSL_TRANSPORT_DATAGRAM

#define MBEDTLS_SSL_TRANSPORT_DATAGRAM         1  /*!< DTLS     */


      

Marco MBEDTLS_SSL_MAX_HOST_NAME_LEN

#define MBEDTLS_SSL_MAX_HOST_NAME_LEN          255 /*!< Maximum host name defined in RFC 1035 */


      

Marco MBEDTLS_SSL_MAX_FRAG_LEN_NONE

#define MBEDTLS_SSL_MAX_FRAG_LEN_NONE          0  /*!< don't use this extension   */
/* RFC 6066 section 4, see also mfl_code_to_length in ssl_tls.c
 * NONE must be zero so that memset()ing structure to zero works */

Marco MBEDTLS_SSL_MAX_FRAG_LEN_512

#define MBEDTLS_SSL_MAX_FRAG_LEN_512           1  /*!< MaxFragmentLength 2^9      */


      

Marco MBEDTLS_SSL_MAX_FRAG_LEN_1024

#define MBEDTLS_SSL_MAX_FRAG_LEN_1024          2  /*!< MaxFragmentLength 2^10     */


      

Marco MBEDTLS_SSL_MAX_FRAG_LEN_2048

#define MBEDTLS_SSL_MAX_FRAG_LEN_2048          3  /*!< MaxFragmentLength 2^11     */


      

Marco MBEDTLS_SSL_MAX_FRAG_LEN_4096

#define MBEDTLS_SSL_MAX_FRAG_LEN_4096          4  /*!< MaxFragmentLength 2^12     */


      

Marco MBEDTLS_SSL_MAX_FRAG_LEN_INVALID

#define MBEDTLS_SSL_MAX_FRAG_LEN_INVALID       5  /*!< first invalid value        */


      

Marco MBEDTLS_SSL_IS_CLIENT

#define MBEDTLS_SSL_IS_CLIENT                  0


      

Marco MBEDTLS_SSL_IS_SERVER

#define MBEDTLS_SSL_IS_SERVER                  1


      

Marco MBEDTLS_SSL_IS_NOT_FALLBACK

#define MBEDTLS_SSL_IS_NOT_FALLBACK            0


      

Marco MBEDTLS_SSL_IS_FALLBACK

#define MBEDTLS_SSL_IS_FALLBACK                1


      

Marco MBEDTLS_SSL_EXTENDED_MS_DISABLED

#define MBEDTLS_SSL_EXTENDED_MS_DISABLED       0


      

Marco MBEDTLS_SSL_EXTENDED_MS_ENABLED

#define MBEDTLS_SSL_EXTENDED_MS_ENABLED        1


      

Marco MBEDTLS_SSL_ETM_DISABLED

#define MBEDTLS_SSL_ETM_DISABLED               0


      

Marco MBEDTLS_SSL_ETM_ENABLED

#define MBEDTLS_SSL_ETM_ENABLED                1


      

Marco MBEDTLS_SSL_COMPRESS_NULL

#define MBEDTLS_SSL_COMPRESS_NULL              0


      

Marco MBEDTLS_SSL_COMPRESS_DEFLATE

#define MBEDTLS_SSL_COMPRESS_DEFLATE           1


      

Marco MBEDTLS_SSL_VERIFY_NONE

#define MBEDTLS_SSL_VERIFY_NONE                0


      

Marco MBEDTLS_SSL_VERIFY_OPTIONAL

#define MBEDTLS_SSL_VERIFY_OPTIONAL            1


      

Marco MBEDTLS_SSL_VERIFY_REQUIRED

#define MBEDTLS_SSL_VERIFY_REQUIRED            2


      

Marco MBEDTLS_SSL_VERIFY_UNSET

#define MBEDTLS_SSL_VERIFY_UNSET               3 /* Used only for sni_authmode */


      

Marco MBEDTLS_SSL_LEGACY_RENEGOTIATION

#define MBEDTLS_SSL_LEGACY_RENEGOTIATION       0


      

Marco MBEDTLS_SSL_SECURE_RENEGOTIATION

#define MBEDTLS_SSL_SECURE_RENEGOTIATION       1


      

Marco MBEDTLS_SSL_RENEGOTIATION_DISABLED

#define MBEDTLS_SSL_RENEGOTIATION_DISABLED     0


      

Marco MBEDTLS_SSL_RENEGOTIATION_ENABLED

#define MBEDTLS_SSL_RENEGOTIATION_ENABLED      1


      

Marco MBEDTLS_SSL_ANTI_REPLAY_DISABLED

#define MBEDTLS_SSL_ANTI_REPLAY_DISABLED       0


      

Marco MBEDTLS_SSL_ANTI_REPLAY_ENABLED

#define MBEDTLS_SSL_ANTI_REPLAY_ENABLED        1


      

Marco MBEDTLS_SSL_RENEGOTIATION_NOT_ENFORCED

#define MBEDTLS_SSL_RENEGOTIATION_NOT_ENFORCED -1


      

Marco MBEDTLS_SSL_RENEGO_MAX_RECORDS_DEFAULT

#define MBEDTLS_SSL_RENEGO_MAX_RECORDS_DEFAULT 16


      

Marco MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION

#define MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION    0


      

Marco MBEDTLS_SSL_LEGACY_ALLOW_RENEGOTIATION

#define MBEDTLS_SSL_LEGACY_ALLOW_RENEGOTIATION 1


      

Marco MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE

#define MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE     2


      

Marco MBEDTLS_SSL_TRUNC_HMAC_DISABLED

#define MBEDTLS_SSL_TRUNC_HMAC_DISABLED        0


      

Marco MBEDTLS_SSL_TRUNC_HMAC_ENABLED

#define MBEDTLS_SSL_TRUNC_HMAC_ENABLED         1


      

Marco MBEDTLS_SSL_TRUNCATED_HMAC_LEN

#define MBEDTLS_SSL_TRUNCATED_HMAC_LEN         10 /* 80 bits, rfc 6066 section 7 */


      

Marco MBEDTLS_SSL_SESSION_TICKETS_DISABLED

#define MBEDTLS_SSL_SESSION_TICKETS_DISABLED    0


      

Marco MBEDTLS_SSL_SESSION_TICKETS_ENABLED

#define MBEDTLS_SSL_SESSION_TICKETS_ENABLED     1


      

Marco MBEDTLS_SSL_CBC_RECORD_SPLITTING_DISABLED

#define MBEDTLS_SSL_CBC_RECORD_SPLITTING_DISABLED   0


      

Marco MBEDTLS_SSL_CBC_RECORD_SPLITTING_ENABLED

#define MBEDTLS_SSL_CBC_RECORD_SPLITTING_ENABLED    1


      

Marco MBEDTLS_SSL_ARC4_ENABLED

#define MBEDTLS_SSL_ARC4_ENABLED               0


      

Marco MBEDTLS_SSL_ARC4_DISABLED

#define MBEDTLS_SSL_ARC4_DISABLED              1


      

Marco MBEDTLS_SSL_PRESET_DEFAULT

#define MBEDTLS_SSL_PRESET_DEFAULT             0


      

Marco MBEDTLS_SSL_PRESET_SUITEB

#define MBEDTLS_SSL_PRESET_SUITEB              2


      

Marco MBEDTLS_SSL_CERT_REQ_CA_LIST_ENABLED

#define MBEDTLS_SSL_CERT_REQ_CA_LIST_ENABLED      1


      

Marco MBEDTLS_SSL_CERT_REQ_CA_LIST_DISABLED

#define MBEDTLS_SSL_CERT_REQ_CA_LIST_DISABLED     0


      

Marco MBEDTLS_SSL_DTLS_SRTP_MKI_UNSUPPORTED

#define MBEDTLS_SSL_DTLS_SRTP_MKI_UNSUPPORTED   0


      

Marco MBEDTLS_SSL_DTLS_SRTP_MKI_SUPPORTED

#define MBEDTLS_SSL_DTLS_SRTP_MKI_SUPPORTED     1


      

Marco MBEDTLS_SSL_DTLS_TIMEOUT_DFL_MIN

#define MBEDTLS_SSL_DTLS_TIMEOUT_DFL_MIN   1000
/*
 * Default range for DTLS retransmission timer value, in milliseconds.
 * RFC 6347 4.2.4.1 says from 1 second to 60 seconds.
 */

Marco MBEDTLS_SSL_DTLS_TIMEOUT_DFL_MAX

#define MBEDTLS_SSL_DTLS_TIMEOUT_DFL_MAX  60000


      

Marco MBEDTLS_SSL_DEFAULT_TICKET_LIFETIME

#define MBEDTLS_SSL_DEFAULT_TICKET_LIFETIME    86400 /**< Lifetime of session tickets (if enabled) */


      

Marco MBEDTLS_SSL_MAX_CONTENT_LEN

#define MBEDTLS_SSL_MAX_CONTENT_LEN        16384  /**< Size of the input / output buffer */


      

Marco MBEDTLS_SSL_IN_CONTENT_LEN

#define MBEDTLS_SSL_IN_CONTENT_LEN MBEDTLS_SSL_MAX_CONTENT_LEN


      

Marco MBEDTLS_SSL_OUT_CONTENT_LEN

#define MBEDTLS_SSL_OUT_CONTENT_LEN MBEDTLS_SSL_MAX_CONTENT_LEN


      

Marco MBEDTLS_SSL_DTLS_MAX_BUFFERING

#define MBEDTLS_SSL_DTLS_MAX_BUFFERING 32768


      

Marco MBEDTLS_SSL_VERIFY_DATA_MAX_LEN

#define MBEDTLS_SSL_VERIFY_DATA_MAX_LEN 36


      

Marco MBEDTLS_SSL_VERIFY_DATA_MAX_LEN

#define MBEDTLS_SSL_VERIFY_DATA_MAX_LEN 12


      

Marco MBEDTLS_SSL_EMPTY_RENEGOTIATION_INFO

#define MBEDTLS_SSL_EMPTY_RENEGOTIATION_INFO   255  /**< renegotiation info ext */
/*
 * Signaling ciphersuite values (SCSV)
 */

Marco MBEDTLS_SSL_FALLBACK_SCSV_VALUE

#define MBEDTLS_SSL_FALLBACK_SCSV_VALUE        22016 /**< RFC 7507 section 2 */


      

Marco MBEDTLS_SSL_HASH_NONE

#define MBEDTLS_SSL_HASH_NONE               0
/*
 * Supported Signature and Hash algorithms (For TLS 1.2)
 * RFC 5246 section 7.4.1.4.1
 */

Marco MBEDTLS_SSL_HASH_MD5

#define MBEDTLS_SSL_HASH_MD5                1


      

Marco MBEDTLS_SSL_HASH_SHA1

#define MBEDTLS_SSL_HASH_SHA1               2


      

Marco MBEDTLS_SSL_HASH_SHA224

#define MBEDTLS_SSL_HASH_SHA224             3


      

Marco MBEDTLS_SSL_HASH_SHA256

#define MBEDTLS_SSL_HASH_SHA256             4


      

Marco MBEDTLS_SSL_HASH_SHA384

#define MBEDTLS_SSL_HASH_SHA384             5


      

Marco MBEDTLS_SSL_HASH_SHA512

#define MBEDTLS_SSL_HASH_SHA512             6


      

Marco MBEDTLS_SSL_SIG_ANON

#define MBEDTLS_SSL_SIG_ANON                0


      

Marco MBEDTLS_SSL_SIG_RSA

#define MBEDTLS_SSL_SIG_RSA                 1


      

Marco MBEDTLS_SSL_SIG_ECDSA

#define MBEDTLS_SSL_SIG_ECDSA               3


      

Marco MBEDTLS_SSL_CERT_TYPE_RSA_SIGN

#define MBEDTLS_SSL_CERT_TYPE_RSA_SIGN      1
/*
 * Client Certificate Types
 * RFC 5246 section 7.4.4 plus RFC 4492 section 5.5
 */

Marco MBEDTLS_SSL_CERT_TYPE_ECDSA_SIGN

#define MBEDTLS_SSL_CERT_TYPE_ECDSA_SIGN   64


      

Marco MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC

#define MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC    20
/*
 * Message, alert and handshake types
 */

Marco MBEDTLS_SSL_MSG_ALERT

#define MBEDTLS_SSL_MSG_ALERT                 21


      

Marco MBEDTLS_SSL_MSG_HANDSHAKE

#define MBEDTLS_SSL_MSG_HANDSHAKE             22


      

Marco MBEDTLS_SSL_MSG_APPLICATION_DATA

#define MBEDTLS_SSL_MSG_APPLICATION_DATA      23


      

Marco MBEDTLS_SSL_ALERT_LEVEL_WARNING

#define MBEDTLS_SSL_ALERT_LEVEL_WARNING        1


      

Marco MBEDTLS_SSL_ALERT_LEVEL_FATAL

#define MBEDTLS_SSL_ALERT_LEVEL_FATAL          2


      

Marco MBEDTLS_SSL_ALERT_MSG_CLOSE_NOTIFY

#define MBEDTLS_SSL_ALERT_MSG_CLOSE_NOTIFY          0 /* 0x00 */


      

Marco MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE

#define MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE   10 /* 0x0A */


      

Marco MBEDTLS_SSL_ALERT_MSG_BAD_RECORD_MAC

#define MBEDTLS_SSL_ALERT_MSG_BAD_RECORD_MAC       20 /* 0x14 */


      

Marco MBEDTLS_SSL_ALERT_MSG_DECRYPTION_FAILED

#define MBEDTLS_SSL_ALERT_MSG_DECRYPTION_FAILED    21 /* 0x15 */


      

Marco MBEDTLS_SSL_ALERT_MSG_RECORD_OVERFLOW

#define MBEDTLS_SSL_ALERT_MSG_RECORD_OVERFLOW      22 /* 0x16 */


      

Marco MBEDTLS_SSL_ALERT_MSG_DECOMPRESSION_FAILURE

#define MBEDTLS_SSL_ALERT_MSG_DECOMPRESSION_FAILURE 30 /* 0x1E */


      

Marco MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE

#define MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE    40 /* 0x28 */


      

Marco MBEDTLS_SSL_ALERT_MSG_NO_CERT

#define MBEDTLS_SSL_ALERT_MSG_NO_CERT              41 /* 0x29 */


      

Marco MBEDTLS_SSL_ALERT_MSG_BAD_CERT

#define MBEDTLS_SSL_ALERT_MSG_BAD_CERT             42 /* 0x2A */


      

Marco MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_CERT

#define MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_CERT     43 /* 0x2B */


      

Marco MBEDTLS_SSL_ALERT_MSG_CERT_REVOKED

#define MBEDTLS_SSL_ALERT_MSG_CERT_REVOKED         44 /* 0x2C */


      

Marco MBEDTLS_SSL_ALERT_MSG_CERT_EXPIRED

#define MBEDTLS_SSL_ALERT_MSG_CERT_EXPIRED         45 /* 0x2D */


      

Marco MBEDTLS_SSL_ALERT_MSG_CERT_UNKNOWN

#define MBEDTLS_SSL_ALERT_MSG_CERT_UNKNOWN         46 /* 0x2E */


      

Marco MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER

#define MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER    47 /* 0x2F */


      

Marco MBEDTLS_SSL_ALERT_MSG_UNKNOWN_CA

#define MBEDTLS_SSL_ALERT_MSG_UNKNOWN_CA           48 /* 0x30 */


      

Marco MBEDTLS_SSL_ALERT_MSG_ACCESS_DENIED

#define MBEDTLS_SSL_ALERT_MSG_ACCESS_DENIED        49 /* 0x31 */


      

Marco MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR

#define MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR         50 /* 0x32 */


      

Marco MBEDTLS_SSL_ALERT_MSG_DECRYPT_ERROR

#define MBEDTLS_SSL_ALERT_MSG_DECRYPT_ERROR        51 /* 0x33 */


      

Marco MBEDTLS_SSL_ALERT_MSG_EXPORT_RESTRICTION

#define MBEDTLS_SSL_ALERT_MSG_EXPORT_RESTRICTION   60 /* 0x3C */


      

Marco MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION

#define MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION     70 /* 0x46 */


      

Marco MBEDTLS_SSL_ALERT_MSG_INSUFFICIENT_SECURITY

#define MBEDTLS_SSL_ALERT_MSG_INSUFFICIENT_SECURITY 71 /* 0x47 */


      

Marco MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR

#define MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR       80 /* 0x50 */


      

Marco MBEDTLS_SSL_ALERT_MSG_INAPROPRIATE_FALLBACK

#define MBEDTLS_SSL_ALERT_MSG_INAPROPRIATE_FALLBACK 86 /* 0x56 */


      

Marco MBEDTLS_SSL_ALERT_MSG_USER_CANCELED

#define MBEDTLS_SSL_ALERT_MSG_USER_CANCELED        90 /* 0x5A */


      

Marco MBEDTLS_SSL_ALERT_MSG_NO_RENEGOTIATION

#define MBEDTLS_SSL_ALERT_MSG_NO_RENEGOTIATION    100 /* 0x64 */


      

Marco MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT

#define MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT     110 /* 0x6E */


      

Marco MBEDTLS_SSL_ALERT_MSG_UNRECOGNIZED_NAME

#define MBEDTLS_SSL_ALERT_MSG_UNRECOGNIZED_NAME   112 /* 0x70 */


      

Marco MBEDTLS_SSL_ALERT_MSG_UNKNOWN_PSK_IDENTITY

#define MBEDTLS_SSL_ALERT_MSG_UNKNOWN_PSK_IDENTITY 115 /* 0x73 */


      

Marco MBEDTLS_SSL_ALERT_MSG_NO_APPLICATION_PROTOCOL

#define MBEDTLS_SSL_ALERT_MSG_NO_APPLICATION_PROTOCOL 120 /* 0x78 */


      

Marco MBEDTLS_SSL_HS_HELLO_REQUEST

#define MBEDTLS_SSL_HS_HELLO_REQUEST           0


      

Marco MBEDTLS_SSL_HS_CLIENT_HELLO

#define MBEDTLS_SSL_HS_CLIENT_HELLO            1


      

Marco MBEDTLS_SSL_HS_SERVER_HELLO

#define MBEDTLS_SSL_HS_SERVER_HELLO            2


      

Marco MBEDTLS_SSL_HS_HELLO_VERIFY_REQUEST

#define MBEDTLS_SSL_HS_HELLO_VERIFY_REQUEST    3


      

Marco MBEDTLS_SSL_HS_NEW_SESSION_TICKET

#define MBEDTLS_SSL_HS_NEW_SESSION_TICKET      4


      

Marco MBEDTLS_SSL_HS_CERTIFICATE

#define MBEDTLS_SSL_HS_CERTIFICATE            11


      

Marco MBEDTLS_SSL_HS_SERVER_KEY_EXCHANGE

#define MBEDTLS_SSL_HS_SERVER_KEY_EXCHANGE    12


      

Marco MBEDTLS_SSL_HS_CERTIFICATE_REQUEST

#define MBEDTLS_SSL_HS_CERTIFICATE_REQUEST    13


      

Marco MBEDTLS_SSL_HS_SERVER_HELLO_DONE

#define MBEDTLS_SSL_HS_SERVER_HELLO_DONE      14


      

Marco MBEDTLS_SSL_HS_CERTIFICATE_VERIFY

#define MBEDTLS_SSL_HS_CERTIFICATE_VERIFY     15


      

Marco MBEDTLS_SSL_HS_CLIENT_KEY_EXCHANGE

#define MBEDTLS_SSL_HS_CLIENT_KEY_EXCHANGE    16


      

Marco MBEDTLS_SSL_HS_FINISHED

#define MBEDTLS_SSL_HS_FINISHED               20


      

Marco MBEDTLS_TLS_EXT_SERVERNAME

#define MBEDTLS_TLS_EXT_SERVERNAME                  0
/*
 * TLS extensions
 */

Marco MBEDTLS_TLS_EXT_SERVERNAME_HOSTNAME

#define MBEDTLS_TLS_EXT_SERVERNAME_HOSTNAME         0


      

Marco MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH

#define MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH         1


      

Marco MBEDTLS_TLS_EXT_TRUNCATED_HMAC

#define MBEDTLS_TLS_EXT_TRUNCATED_HMAC              4


      

Marco MBEDTLS_TLS_EXT_SUPPORTED_ELLIPTIC_CURVES

#define MBEDTLS_TLS_EXT_SUPPORTED_ELLIPTIC_CURVES  10


      

Marco MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS

#define MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS    11


      

Marco MBEDTLS_TLS_EXT_SIG_ALG

#define MBEDTLS_TLS_EXT_SIG_ALG                    13


      

Marco MBEDTLS_TLS_EXT_USE_SRTP

#define MBEDTLS_TLS_EXT_USE_SRTP                   14


      

Marco MBEDTLS_TLS_EXT_ALPN

#define MBEDTLS_TLS_EXT_ALPN                       16


      

Marco MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC

#define MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC           22 /* 0x16 */


      

Marco MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET

#define MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET 23 /* 23 */


      

Marco MBEDTLS_TLS_EXT_SESSION_TICKET

#define MBEDTLS_TLS_EXT_SESSION_TICKET             35


      

Marco MBEDTLS_TLS_EXT_ECJPAKE_KKPP

#define MBEDTLS_TLS_EXT_ECJPAKE_KKPP              256 /* experimental */


      

Marco MBEDTLS_TLS_EXT_RENEGOTIATION_INFO

#define MBEDTLS_TLS_EXT_RENEGOTIATION_INFO     65281


      

Marco MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_80_IANA_VALUE

#define MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_80_IANA_VALUE    1
/*
 * use_srtp extension protection profiles values as defined in http://www.iana.org/assignments/srtp-protection/srtp-protection.xhtml
 */

Marco MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_32_IANA_VALUE

#define MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_32_IANA_VALUE    2


      

Marco MBEDTLS_SRTP_NULL_HMAC_SHA1_80_IANA_VALUE

#define MBEDTLS_SRTP_NULL_HMAC_SHA1_80_IANA_VALUE         5


      

Marco MBEDTLS_SRTP_NULL_HMAC_SHA1_32_IANA_VALUE

#define MBEDTLS_SRTP_NULL_HMAC_SHA1_32_IANA_VALUE         6


      

Marco MBEDTLS_PSK_MAX_LEN

#define MBEDTLS_PSK_MAX_LEN           64 /* 256 bits */
//#define MBEDTLS_PSK_MAX_LEN            32 /* 256 bits */

Marco MBEDTLS_PREMASTER_SIZE

#define MBEDTLS_PREMASTER_SIZE    sizeof( union mbedtls_ssl_premaster_secret )


      

Marco MBEDTLS_DTLS_SRTP_MAX_KEY_MATERIAL_LENGTH

#define MBEDTLS_DTLS_SRTP_MAX_KEY_MATERIAL_LENGTH   60


      

Marco MBEDTLS_DTLS_SRTP_MAX_MKI_LENGTH

#define MBEDTLS_DTLS_SRTP_MAX_MKI_LENGTH            255


      

Marco MBEDTLS_SSL_CHANNEL_OUTBOUND

#define MBEDTLS_SSL_CHANNEL_OUTBOUND   0


      

Marco MBEDTLS_SSL_CHANNEL_INBOUND

#define MBEDTLS_SSL_CHANNEL_INBOUND    1


      

Marco MBEDTLS_DEPRECATED

#define MBEDTLS_DEPRECATED   __attribute__((deprecated))


      

Marco MBEDTLS_DEPRECATED

#define MBEDTLS_DEPRECATED

      

Functions

Func mbedtls_ssl_get_ciphersuite_id

int mbedtls_ssl_get_ciphersuite_id( const char *ciphersuite_name );
/**
 * \brief               Return the ID of the ciphersuite associated with the
 *                      given name
 *
 * \param ciphersuite_name SSL ciphersuite name
 *
 * \return              the ID with the ciphersuite or 0 if not found
 */

Func mbedtls_ssl_init

void mbedtls_ssl_init( mbedtls_ssl_context *ssl );
/**
 * \brief          Initialize an SSL context
 *                 Just makes the context ready for mbedtls_ssl_setup() or
 *                 mbedtls_ssl_free()
 *
 * \param ssl      SSL context
 */

Func mbed_tls_reset_in_buf_len

void mbed_tls_reset_in_buf_len(mbedtls_ssl_context *ssl, unsigned int new_len);


      

Func mbed_tls_reset_out_buf_len

void mbed_tls_reset_out_buf_len(mbedtls_ssl_context *ssl, unsigned int new_len);


      

Func mbedtls_ssl_setup

int mbedtls_ssl_setup( mbedtls_ssl_context *ssl,
                      const mbedtls_ssl_config *conf );
/**
 * \brief          Set up an SSL context for use
 *
 * \note           No copy of the configuration context is made, it can be
 *                 shared by many mbedtls_ssl_context structures.
 *
 * \warning        The conf structure will be accessed during the session.
 *                 It must not be modified or freed as long as the session
 *                 is active.
 *
 * \warning        This function must be called exactly once per context.
 *                 Calling mbedtls_ssl_setup again is not supported, even
 *                 if no session is active.
 *
 * \param ssl      SSL context
 * \param conf     SSL configuration to use
 *
 * \return         0 if successful, or MBEDTLS_ERR_SSL_ALLOC_FAILED if
 *                 memory allocation failed
 */

Func mbedtls_ssl_session_reset

int mbedtls_ssl_session_reset( mbedtls_ssl_context *ssl );
/**
 * \brief          Reset an already initialized SSL context for re-use
 *                 while retaining application-set variables, function
 *                 pointers and data.
 *
 * \param ssl      SSL context
 * \return         0 if successful, or MBEDTLS_ERR_SSL_ALLOC_FAILED,
                   MBEDTLS_ERR_SSL_HW_ACCEL_FAILED or
 *                 MBEDTLS_ERR_SSL_COMPRESSION_FAILED
 */

Func mbedtls_ssl_conf_endpoint

void mbedtls_ssl_conf_endpoint( mbedtls_ssl_config *conf, int endpoint );
/**
 * \brief          Set the current endpoint type
 *
 * \param conf     SSL configuration
 * \param endpoint must be MBEDTLS_SSL_IS_CLIENT or MBEDTLS_SSL_IS_SERVER
 */

Func mbedtls_ssl_conf_transport

void mbedtls_ssl_conf_transport( mbedtls_ssl_config *conf, int transport );
/**
 * \brief           Set the transport type (TLS or DTLS).
 *                  Default: TLS
 *
 * \note            For DTLS, you must either provide a recv callback that
 *                  doesn't block, or one that handles timeouts, see
 *                  \c mbedtls_ssl_set_bio(). You also need to provide timer
 *                  callbacks with \c mbedtls_ssl_set_timer_cb().
 *
 * \param conf      SSL configuration
 * \param transport transport type:
 *                  MBEDTLS_SSL_TRANSPORT_STREAM for TLS,
 *                  MBEDTLS_SSL_TRANSPORT_DATAGRAM for DTLS.
 */

Func mbedtls_ssl_conf_authmode

void mbedtls_ssl_conf_authmode( mbedtls_ssl_config *conf, int authmode );
/**
 * \brief          Set the certificate verification mode
 *                 Default: NONE on server, REQUIRED on client
 *
 * \param conf     SSL configuration
 * \param authmode can be:
 *
 *  MBEDTLS_SSL_VERIFY_NONE:      peer certificate is not checked
 *                        (default on server)
 *                        (insecure on client)
 *
 *  MBEDTLS_SSL_VERIFY_OPTIONAL:  peer certificate is checked, however the
 *                        handshake continues even if verification failed;
 *                        mbedtls_ssl_get_verify_result() can be called after the
 *                        handshake is complete.
 *
 *  MBEDTLS_SSL_VERIFY_REQUIRED:  peer *must* present a valid certificate,
 *                        handshake is aborted if verification failed.
 *                        (default on client)
 *
 * \note On client, MBEDTLS_SSL_VERIFY_REQUIRED is the recommended mode.
 * With MBEDTLS_SSL_VERIFY_OPTIONAL, the user needs to call mbedtls_ssl_get_verify_result() at
 * the right time(s), which may not be obvious, while REQUIRED always perform
 * the verification as soon as possible. For example, REQUIRED was protecting
 * against the "triple handshake" attack even before it was found.
 */

Func mbedtls_ssl_conf_verify

void mbedtls_ssl_conf_verify( mbedtls_ssl_config *conf,
                    int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
                    void *p_vrfy );
/**
 * \brief          Set the verification callback (Optional).
 *
 *                 If set, the verify callback is called for each
 *                 certificate in the chain. For implementation
 *                 information, please see \c mbedtls_x509_crt_verify()
 *
 * \param conf     SSL configuration
 * \param f_vrfy   verification function
 * \param p_vrfy   verification parameter
 */

Func mbedtls_ssl_conf_rng

void mbedtls_ssl_conf_rng( mbedtls_ssl_config *conf,
                 int (*f_rng)(void *, unsigned char *, size_t),
                 void *p_rng );
/**
 * \brief          Set the random number generator callback
 *
 * \param conf     SSL configuration
 * \param f_rng    RNG function
 * \param p_rng    RNG parameter
 */

Func mbedtls_ssl_conf_dbg

void mbedtls_ssl_conf_dbg( mbedtls_ssl_config *conf,
                 void (*f_dbg)(void *, int, const char *, int, const char *),
                 void *p_dbg );
/**
 * \brief          Set the debug callback
 *
 *                 The callback has the following argument:
 *                 void *           opaque context for the callback
 *                 int              debug level
 *                 const char *     file name
 *                 int              line number
 *                 const char *     message
 *
 * \param conf     SSL configuration
 * \param f_dbg    debug function
 * \param p_dbg    debug parameter
 */

Func mbedtls_ssl_set_bio

void mbedtls_ssl_set_bio( mbedtls_ssl_context *ssl,
                         void *p_bio,
                         mbedtls_ssl_send_t *f_send,
                         mbedtls_ssl_recv_t *f_recv,
                         mbedtls_ssl_recv_timeout_t *f_recv_timeout );
/**
 * \brief          Set the underlying BIO callbacks for write, read and
 *                 read-with-timeout.
 *
 * \param ssl      SSL context
 * \param p_bio    parameter (context) shared by BIO callbacks
 * \param f_send   write callback
 * \param f_recv   read callback
 * \param f_recv_timeout blocking read callback with timeout.
 *
 * \note           One of f_recv or f_recv_timeout can be NULL, in which case
 *                 the other is used. If both are non-NULL, f_recv_timeout is
 *                 used and f_recv is ignored (as if it were NULL).
 *
 * \note           The two most common use cases are:
 *                 - non-blocking I/O, f_recv != NULL, f_recv_timeout == NULL
 *                 - blocking I/O, f_recv == NULL, f_recv_timout != NULL
 *
 * \note           For DTLS, you need to provide either a non-NULL
 *                 f_recv_timeout callback, or a f_recv that doesn't block.
 *
 * \note           See the documentations of \c mbedtls_ssl_sent_t,
 *                 \c mbedtls_ssl_recv_t and \c mbedtls_ssl_recv_timeout_t for
 *                 the conventions those callbacks must follow.
 *
 * \note           On some platforms, net_sockets.c provides
 *                 \c mbedtls_net_send(), \c mbedtls_net_recv() and
 *                 \c mbedtls_net_recv_timeout() that are suitable to be used
 *                 here.
 */

Func mbedtls_ssl_set_mtu

void mbedtls_ssl_set_mtu( mbedtls_ssl_context *ssl, uint16_t mtu );
/**
 * \brief          Set the Maximum Tranport Unit (MTU).
 *                 Special value: 0 means unset (no limit).
 *                 This represents the maximum size of a datagram payload
 *                 handled by the transport layer (usually UDP) as determined
 *                 by the network link and stack. In practice, this controls
 *                 the maximum size datagram the DTLS layer will pass to the
 *                 \c f_send() callback set using \c mbedtls_ssl_set_bio().
 *
 * \note           The limit on datagram size is converted to a limit on
 *                 record payload by subtracting the current overhead of
 *                 encapsulation and encryption/authentication if any.
 *
 * \note           This can be called at any point during the connection, for
 *                 example when a Path Maximum Transfer Unit (PMTU)
 *                 estimate becomes available from other sources,
 *                 such as lower (or higher) protocol layers.
 *
 * \note           This setting only controls the size of the packets we send,
 *                 and does not restrict the size of the datagrams we're
 *                 willing to receive. Client-side, you can request the
 *                 server to use smaller records with \c
 *                 mbedtls_ssl_conf_max_frag_len().
 *
 * \note           If both a MTU and a maximum fragment length have been
 *                 configured (or negotiated with the peer), the resulting
 *                 lower limit on record payload (see first note) is used.
 *
 * \note           This can only be used to decrease the maximum size
 *                 of datagrams (hence records, see first note) sent. It
 *                 cannot be used to increase the maximum size of records over
 *                 the limit set by #MBEDTLS_SSL_OUT_CONTENT_LEN.
 *
 * \note           Values lower than the current record layer expansion will
 *                 result in an error when trying to send data.
 *
 * \note           Using record compression together with a non-zero MTU value
 *                 will result in an error when trying to send data.
 *
 * \param ssl      SSL context
 * \param mtu      Value of the path MTU in bytes
 */

Func mbedtls_ssl_conf_read_timeout

void mbedtls_ssl_conf_read_timeout( mbedtls_ssl_config *conf, uint32_t timeout );
/**
 * \brief          Set the timeout period for mbedtls_ssl_read()
 *                 (Default: no timeout.)
 *
 * \param conf     SSL configuration context
 * \param timeout  Timeout value in milliseconds.
 *                 Use 0 for no timeout (default).
 *
 * \note           With blocking I/O, this will only work if a non-NULL
 *                 \c f_recv_timeout was set with \c mbedtls_ssl_set_bio().
 *                 With non-blocking I/O, this will only work if timer
 *                 callbacks were set with \c mbedtls_ssl_set_timer_cb().
 *
 * \note           With non-blocking I/O, you may also skip this function
 *                 altogether and handle timeouts at the application layer.
 */

Func mbedtls_ssl_set_timer_cb

void mbedtls_ssl_set_timer_cb( mbedtls_ssl_context *ssl,
                              void *p_timer,
                              mbedtls_ssl_set_timer_t *f_set_timer,
                              mbedtls_ssl_get_timer_t *f_get_timer );
/**
 * \brief          Set the timer callbacks (Mandatory for DTLS.)
 *
 * \param ssl      SSL context
 * \param p_timer  parameter (context) shared by timer callbacks
 * \param f_set_timer   set timer callback
 * \param f_get_timer   get timer callback. Must return:
 *
 * \note           See the documentation of \c mbedtls_ssl_set_timer_t and
 *                 \c mbedtls_ssl_get_timer_t for the conventions this pair of
 *                 callbacks must follow.
 *
 * \note           On some platforms, timing.c provides
 *                 \c mbedtls_timing_set_delay() and
 *                 \c mbedtls_timing_get_delay() that are suitable for using
 *                 here, except if using an event-driven style.
 *
 * \note           See also the "DTLS tutorial" article in our knowledge base.
 *                 https://tls.mbed.org/kb/how-to/dtls-tutorial
 */

Func mbedtls_ssl_conf_session_tickets_cb

void mbedtls_ssl_conf_session_tickets_cb( mbedtls_ssl_config *conf,
       mbedtls_ssl_ticket_write_t *f_ticket_write,
       mbedtls_ssl_ticket_parse_t *f_ticket_parse,
       void *p_ticket );
/**
 * \brief           Configure SSL session ticket callbacks (server only).
 *                  (Default: none.)
 *
 * \note            On server, session tickets are enabled by providing
 *                  non-NULL callbacks.
 *
 * \note            On client, use \c mbedtls_ssl_conf_session_tickets().
 *
 * \param conf      SSL configuration context
 * \param f_ticket_write    Callback for writing a ticket
 * \param f_ticket_parse    Callback for parsing a ticket
 * \param p_ticket          Context shared by the two callbacks
 */

Func mbedtls_ssl_conf_export_keys_cb

void mbedtls_ssl_conf_export_keys_cb( mbedtls_ssl_config *conf,
       mbedtls_ssl_export_keys_t *f_export_keys,
       void *p_export_keys );
/**
 * \brief           Configure key export callback.
 *                  (Default: none.)
 *
 * \note            See \c mbedtls_ssl_export_keys_t.
 *
 * \param conf      SSL configuration context
 * \param f_export_keys     Callback for exporting keys
 * \param p_export_keys     Context for the callback
 */

Func mbedtls_ssl_conf_async_private_cb

void mbedtls_ssl_conf_async_private_cb( mbedtls_ssl_config *conf,
                                       mbedtls_ssl_async_sign_t *f_async_sign,
                                       mbedtls_ssl_async_decrypt_t *f_async_decrypt,
                                       mbedtls_ssl_async_resume_t *f_async_resume,
                                       mbedtls_ssl_async_cancel_t *f_async_cancel,
                                       void *config_data );
/**
 * \brief           Configure asynchronous private key operation callbacks.
 *
 * \param conf              SSL configuration context
 * \param f_async_sign      Callback to start a signature operation. See
 *                          the description of ::mbedtls_ssl_async_sign_t
 *                          for more information. This may be \c NULL if the
 *                          external processor does not support any signature
 *                          operation; in this case the private key object
 *                          associated with the certificate will be used.
 * \param f_async_decrypt   Callback to start a decryption operation. See
 *                          the description of ::mbedtls_ssl_async_decrypt_t
 *                          for more information. This may be \c NULL if the
 *                          external processor does not support any decryption
 *                          operation; in this case the private key object
 *                          associated with the certificate will be used.
 * \param f_async_resume    Callback to resume an asynchronous operation. See
 *                          the description of ::mbedtls_ssl_async_resume_t
 *                          for more information. This may not be \c NULL unless
 *                          \p f_async_sign and \p f_async_decrypt are both
 *                          \c NULL.
 * \param f_async_cancel    Callback to cancel an asynchronous operation. See
 *                          the description of ::mbedtls_ssl_async_cancel_t
 *                          for more information. This may be \c NULL if
 *                          no cleanup is needed.
 * \param config_data       A pointer to configuration data which can be
 *                          retrieved with
 *                          mbedtls_ssl_conf_get_async_config_data(). The
 *                          library stores this value without dereferencing it.
 */

Func mbedtls_ssl_conf_get_async_config_data

void *mbedtls_ssl_conf_get_async_config_data( const mbedtls_ssl_config *conf );
/**
 * \brief           Retrieve the configuration data set by
 *                  mbedtls_ssl_conf_async_private_cb().
 *
 * \param conf      SSL configuration context
 * \return          The configuration data set by
 *                  mbedtls_ssl_conf_async_private_cb().
 */

Func mbedtls_ssl_get_async_operation_data

void *mbedtls_ssl_get_async_operation_data( const mbedtls_ssl_context *ssl );
/**
 * \brief           Retrieve the asynchronous operation user context.
 *
 * \note            This function may only be called while a handshake
 *                  is in progress.
 *
 * \param ssl       The SSL context to access.
 *
 * \return          The asynchronous operation user context that was last
 *                  set during the current handshake. If
 *                  mbedtls_ssl_set_async_operation_data() has not yet been
 *                  called during the current handshake, this function returns
 *                  \c NULL.
 */

Func mbedtls_ssl_set_async_operation_data

void mbedtls_ssl_set_async_operation_data( mbedtls_ssl_context *ssl,
                                void *ctx );
/**
 * \brief           Retrieve the asynchronous operation user context.
 *
 * \note            This function may only be called while a handshake
 *                  is in progress.
 *
 * \param ssl       The SSL context to access.
 * \param ctx       The new value of the asynchronous operation user context.
 *                  Call mbedtls_ssl_get_async_operation_data() later during the
 *                  same handshake to retrieve this value.
 */

Func mbedtls_ssl_conf_dtls_cookies

void mbedtls_ssl_conf_dtls_cookies( mbedtls_ssl_config *conf,
                          mbedtls_ssl_cookie_write_t *f_cookie_write,
                          mbedtls_ssl_cookie_check_t *f_cookie_check,
                          void *p_cookie );
/**
 * \brief           Register callbacks for DTLS cookies
 *                  (Server only. DTLS only.)
 *
 *                  Default: dummy callbacks that fail, in order to force you to
 *                  register working callbacks (and initialize their context).
 *
 *                  To disable HelloVerifyRequest, register NULL callbacks.
 *
 * \warning         Disabling hello verification allows your server to be used
 *                  for amplification in DoS attacks against other hosts.
 *                  Only disable if you known this can't happen in your
 *                  particular environment.
 *
 * \note            See comments on \c mbedtls_ssl_handshake() about handling
 *                  the MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED that is expected
 *                  on the first handshake attempt when this is enabled.
 *
 * \note            This is also necessary to handle client reconnection from
 *                  the same port as described in RFC 6347 section 4.2.8 (only
 *                  the variant with cookies is supported currently). See
 *                  comments on \c mbedtls_ssl_read() for details.
 *
 * \param conf              SSL configuration
 * \param f_cookie_write    Cookie write callback
 * \param f_cookie_check    Cookie check callback
 * \param p_cookie          Context for both callbacks
 */

Func mbedtls_ssl_set_client_transport_id

int mbedtls_ssl_set_client_transport_id( mbedtls_ssl_context *ssl,
                                const unsigned char *info,
                                size_t ilen );
/**
 * \brief          Set client's transport-level identification info.
 *                 (Server only. DTLS only.)
 *
 *                 This is usually the IP address (and port), but could be
 *                 anything identify the client depending on the underlying
 *                 network stack. Used for HelloVerifyRequest with DTLS.
 *                 This is *not* used to route the actual packets.
 *
 * \param ssl      SSL context
 * \param info     Transport-level info identifying the client (eg IP + port)
 * \param ilen     Length of info in bytes
 *
 * \note           An internal copy is made, so the info buffer can be reused.
 *
 * \return         0 on success,
 *                 MBEDTLS_ERR_SSL_BAD_INPUT_DATA if used on client,
 *                 MBEDTLS_ERR_SSL_ALLOC_FAILED if out of memory.
 */

Func mbedtls_ssl_conf_dtls_anti_replay

void mbedtls_ssl_conf_dtls_anti_replay( mbedtls_ssl_config *conf, char mode );
/**
 * \brief          Enable or disable anti-replay protection for DTLS.
 *                 (DTLS only, no effect on TLS.)
 *                 Default: enabled.
 *
 * \param conf     SSL configuration
 * \param mode     MBEDTLS_SSL_ANTI_REPLAY_ENABLED or MBEDTLS_SSL_ANTI_REPLAY_DISABLED.
 *
 * \warning        Disabling this is a security risk unless the application
 *                 protocol handles duplicated packets in a safe way. You
 *                 should not disable this without careful consideration.
 *                 However, if your application already detects duplicated
 *                 packets and needs information about them to adjust its
 *                 transmission strategy, then you'll want to disable this.
 */

Func mbedtls_ssl_conf_dtls_badmac_limit

void mbedtls_ssl_conf_dtls_badmac_limit( mbedtls_ssl_config *conf, unsigned limit );
/**
 * \brief          Set a limit on the number of records with a bad MAC
 *                 before terminating the connection.
 *                 (DTLS only, no effect on TLS.)
 *                 Default: 0 (disabled).
 *
 * \param conf     SSL configuration
 * \param limit    Limit, or 0 to disable.
 *
 * \note           If the limit is N, then the connection is terminated when
 *                 the Nth non-authentic record is seen.
 *
 * \note           Records with an invalid header are not counted, only the
 *                 ones going through the authentication-decryption phase.
 *
 * \note           This is a security trade-off related to the fact that it's
 *                 often relatively easy for an active attacker ot inject UDP
 *                 datagrams. On one hand, setting a low limit here makes it
 *                 easier for such an attacker to forcibly terminated a
 *                 connection. On the other hand, a high limit or no limit
 *                 might make us waste resources checking authentication on
 *                 many bogus packets.
 */

Func mbedtls_ssl_set_datagram_packing

void mbedtls_ssl_set_datagram_packing( mbedtls_ssl_context *ssl,
                                      unsigned allow_packing );
/**
 * \brief          Allow or disallow packing of multiple handshake records
 *                 within a single datagram.
 *
 * \param ssl           The SSL context to configure.
 * \param allow_packing This determines whether datagram packing may
 *                      be used or not. A value of \c 0 means that every
 *                      record will be sent in a separate datagram; a
 *                      value of \c 1 means that, if space permits,
 *                      multiple handshake messages (including CCS) belonging to
 *                      a single flight may be packed within a single datagram.
 *
 * \note           This is enabled by default and should only be disabled
 *                 for test purposes, or if datagram packing causes
 *                 interoperability issues with peers that don't support it.
 *
 * \note           Allowing datagram packing reduces the network load since
 *                 there's less overhead if multiple messages share the same
 *                 datagram. Also, it increases the handshake efficiency
 *                 since messages belonging to a single datagram will not
 *                 be reordered in transit, and so future message buffering
 *                 or flight retransmission (if no buffering is used) as
 *                 means to deal with reordering are needed less frequently.
 *
 * \note           Application records are not affected by this option and
 *                 are currently always sent in separate datagrams.
 *
 */

Func mbedtls_ssl_conf_handshake_timeout

void mbedtls_ssl_conf_handshake_timeout( mbedtls_ssl_config *conf, uint32_t min, uint32_t max );
/**
 * \brief          Set retransmit timeout values for the DTLS handshake.
 *                 (DTLS only, no effect on TLS.)
 *
 * \param conf     SSL configuration
 * \param min      Initial timeout value in milliseconds.
 *                 Default: 1000 (1 second).
 * \param max      Maximum timeout value in milliseconds.
 *                 Default: 60000 (60 seconds).
 *
 * \note           Default values are from RFC 6347 section 4.2.4.1.
 *
 * \note           The 'min' value should typically be slightly above the
 *                 expected round-trip time to your peer, plus whatever time
 *                 it takes for the peer to process the message. For example,
 *                 if your RTT is about 600ms and you peer needs up to 1s to
 *                 do the cryptographic operations in the handshake, then you
 *                 should set 'min' slightly above 1600. Lower values of 'min'
 *                 might cause spurious resends which waste network resources,
 *                 while larger value of 'min' will increase overall latency
 *                 on unreliable network links.
 *
 * \note           The more unreliable your network connection is, the larger
 *                 your max / min ratio needs to be in order to achieve
 *                 reliable handshakes.
 *
 * \note           Messages are retransmitted up to log2(ceil(max/min)) times.
 *                 For example, if min = 1s and max = 5s, the retransmit plan
 *                 goes: send ... 1s -> resend ... 2s -> resend ... 4s ->
 *                 resend ... 5s -> give up and return a timeout error.
 */

Func mbedtls_ssl_conf_session_cache

void mbedtls_ssl_conf_session_cache( mbedtls_ssl_config *conf,
       void *p_cache,
       int (*f_get_cache)(void *, mbedtls_ssl_session *),
       int (*f_set_cache)(void *, const mbedtls_ssl_session *) );
/**
 * \brief          Set the session cache callbacks (server-side only)
 *                 If not set, no session resuming is done (except if session
 *                 tickets are enabled too).
 *
 *                 The session cache has the responsibility to check for stale
 *                 entries based on timeout. See RFC 5246 for recommendations.
 *
 *                 Warning: session.peer_cert is cleared by the SSL/TLS layer on
 *                 connection shutdown, so do not cache the pointer! Either set
 *                 it to NULL or make a full copy of the certificate.
 *
 *                 The get callback is called once during the initial handshake
 *                 to enable session resuming. The get function has the
 *                 following parameters: (void *parameter, mbedtls_ssl_session *session)
 *                 If a valid entry is found, it should fill the master of
 *                 the session object with the cached values and return 0,
 *                 return 1 otherwise. Optionally peer_cert can be set as well
 *                 if it is properly present in cache entry.
 *
 *                 The set callback is called once during the initial handshake
 *                 to enable session resuming after the entire handshake has
 *                 been finished. The set function has the following parameters:
 *                 (void *parameter, const mbedtls_ssl_session *session). The function
 *                 should create a cache entry for future retrieval based on
 *                 the data in the session structure and should keep in mind
 *                 that the mbedtls_ssl_session object presented (and all its referenced
 *                 data) is cleared by the SSL/TLS layer when the connection is
 *                 terminated. It is recommended to add metadata to determine if
 *                 an entry is still valid in the future. Return 0 if
 *                 successfully cached, return 1 otherwise.
 *
 * \param conf           SSL configuration
 * \param p_cache        parmater (context) for both callbacks
 * \param f_get_cache    session get callback
 * \param f_set_cache    session set callback
 */

Func mbedtls_ssl_set_session

int mbedtls_ssl_set_session( mbedtls_ssl_context *ssl, const mbedtls_ssl_session *session );
/**
 * \brief          Request resumption of session (client-side only)
 *                 Session data is copied from presented session structure.
 *
 * \param ssl      SSL context
 * \param session  session context
 *
 * \return         0 if successful,
 *                 MBEDTLS_ERR_SSL_ALLOC_FAILED if memory allocation failed,
 *                 MBEDTLS_ERR_SSL_BAD_INPUT_DATA if used server-side or
 *                 arguments are otherwise invalid
 *
 * \sa             mbedtls_ssl_get_session()
 */

Func mbedtls_ssl_conf_ciphersuites

void mbedtls_ssl_conf_ciphersuites( mbedtls_ssl_config *conf,
                                  const int *ciphersuites );
/**
 * \brief               Set the list of allowed ciphersuites and the preference
 *                      order. First in the list has the highest preference.
 *                      (Overrides all version-specific lists)
 *
 *                      The ciphersuites array is not copied, and must remain
 *                      valid for the lifetime of the ssl_config.
 *
 *                      Note: The server uses its own preferences
 *                      over the preference of the client unless
 *                      MBEDTLS_SSL_SRV_RESPECT_CLIENT_PREFERENCE is defined!
 *
 * \param conf          SSL configuration
 * \param ciphersuites  0-terminated list of allowed ciphersuites
 */

Func mbedtls_ssl_conf_ciphersuites_for_version

void mbedtls_ssl_conf_ciphersuites_for_version( mbedtls_ssl_config *conf,
                                      const int *ciphersuites,
                                      int major, int minor );
/**
 * \brief               Set the list of allowed ciphersuites and the
 *                      preference order for a specific version of the protocol.
 *                      (Only useful on the server side)
 *
 *                      The ciphersuites array is not copied, and must remain
 *                      valid for the lifetime of the ssl_config.
 *
 * \param conf          SSL configuration
 * \param ciphersuites  0-terminated list of allowed ciphersuites
 * \param major         Major version number (only MBEDTLS_SSL_MAJOR_VERSION_3
 *                      supported)
 * \param minor         Minor version number (MBEDTLS_SSL_MINOR_VERSION_0,
 *                      MBEDTLS_SSL_MINOR_VERSION_1 and MBEDTLS_SSL_MINOR_VERSION_2,
 *                      MBEDTLS_SSL_MINOR_VERSION_3 supported)
 *
 * \note                With DTLS, use MBEDTLS_SSL_MINOR_VERSION_2 for DTLS 1.0
 *                      and MBEDTLS_SSL_MINOR_VERSION_3 for DTLS 1.2
 */

Func mbedtls_ssl_conf_cert_profile

void mbedtls_ssl_conf_cert_profile( mbedtls_ssl_config *conf,
                                   const mbedtls_x509_crt_profile *profile );
/**
 * \brief          Set the X.509 security profile used for verification
 *
 * \note           The restrictions are enforced for all certificates in the
 *                 chain. However, signatures in the handshake are not covered
 *                 by this setting but by \b mbedtls_ssl_conf_sig_hashes().
 *
 * \param conf     SSL configuration
 * \param profile  Profile to use
 */

Func mbedtls_ssl_conf_ca_chain

void mbedtls_ssl_conf_ca_chain( mbedtls_ssl_config *conf,
                              mbedtls_x509_crt *ca_chain,
                              mbedtls_x509_crl *ca_crl );
/**
 * \brief          Set the data required to verify peer certificate
 *
 * \note           See \c mbedtls_x509_crt_verify() for notes regarding the
 *                 parameters ca_chain (maps to trust_ca for that function)
 *                 and ca_crl.
 *
 * \param conf     SSL configuration
 * \param ca_chain trusted CA chain (meaning all fully trusted top-level CAs)
 * \param ca_crl   trusted CA CRLs
 */

Func mbedtls_ssl_conf_own_cert

int mbedtls_ssl_conf_own_cert( mbedtls_ssl_config *conf,
                             mbedtls_x509_crt *own_cert,
                             mbedtls_pk_context *pk_key );
/**
 * \brief          Set own certificate chain and private key
 *
 * \note           own_cert should contain in order from the bottom up your
 *                 certificate chain. The top certificate (self-signed)
 *                 can be omitted.
 *
 * \note           On server, this function can be called multiple times to
 *                 provision more than one cert/key pair (eg one ECDSA, one
 *                 RSA with SHA-256, one RSA with SHA-1). An adequate
 *                 certificate will be selected according to the client's
 *                 advertised capabilities. In case mutliple certificates are
 *                 adequate, preference is given to the one set by the first
 *                 call to this function, then second, etc.
 *
 * \note           On client, only the first call has any effect. That is,
 *                 only one client certificate can be provisioned. The
 *                 server's preferences in its CertficateRequest message will
 *                 be ignored and our only cert will be sent regardless of
 *                 whether it matches those preferences - the server can then
 *                 decide what it wants to do with it.
 *
 * \note           The provided \p pk_key needs to match the public key in the
 *                 first certificate in \p own_cert, or all handshakes using
 *                 that certificate will fail. It is your responsibility
 *                 to ensure that; this function will not perform any check.
 *                 You may use mbedtls_pk_check_pair() in order to perform
 *                 this check yourself, but be aware that this function can
 *                 be computationally expensive on some key types.
 *
 * \param conf     SSL configuration
 * \param own_cert own public certificate chain
 * \param pk_key   own private key
 *
 * \return         0 on success or MBEDTLS_ERR_SSL_ALLOC_FAILED
 */

Func mbedtls_ssl_conf_psk

int mbedtls_ssl_conf_psk( mbedtls_ssl_config *conf,
               const unsigned char *psk, size_t psk_len,
               const unsigned char *psk_identity, size_t psk_identity_len );
/**
 * \brief          Set the Pre Shared Key (PSK) and the expected identity name
 *
 * \note           This is mainly useful for clients. Servers will usually
 *                 want to use \c mbedtls_ssl_conf_psk_cb() instead.
 *
 * \note           Currently clients can only register one pre-shared key.
 *                 In other words, the servers' identity hint is ignored.
 *                 Support for setting multiple PSKs on clients and selecting
 *                 one based on the identity hint is not a planned feature but
 *                 feedback is welcomed.
 *
 * \param conf     SSL configuration
 * \param psk      pointer to the pre-shared key
 * \param psk_len  pre-shared key length
 * \param psk_identity      pointer to the pre-shared key identity
 * \param psk_identity_len  identity key length
 *
 * \return         0 if successful or MBEDTLS_ERR_SSL_ALLOC_FAILED
 */

Func mbedtls_ssl_set_hs_psk

int mbedtls_ssl_set_hs_psk( mbedtls_ssl_context *ssl,
                           const unsigned char *psk, size_t psk_len );
/**
 * \brief          Set the Pre Shared Key (PSK) for the current handshake
 *
 * \note           This should only be called inside the PSK callback,
 *                 ie the function passed to \c mbedtls_ssl_conf_psk_cb().
 *
 * \param ssl      SSL context
 * \param psk      pointer to the pre-shared key
 * \param psk_len  pre-shared key length
 *
 * \return         0 if successful or MBEDTLS_ERR_SSL_ALLOC_FAILED
 */

Func mbedtls_ssl_conf_psk_cb

void mbedtls_ssl_conf_psk_cb( mbedtls_ssl_config *conf,
                    int (*f_psk)(void *, mbedtls_ssl_context *, const unsigned char *,
                                 size_t),
                    void *p_psk );
/**
 * \brief          Set the PSK callback (server-side only).
 *
 *                 If set, the PSK callback is called for each
 *                 handshake where a PSK ciphersuite was negotiated.
 *                 The caller provides the identity received and wants to
 *                 receive the actual PSK data and length.
 *
 *                 The callback has the following parameters: (void *parameter,
 *                 mbedtls_ssl_context *ssl, const unsigned char *psk_identity,
 *                 size_t identity_len)
 *                 If a valid PSK identity is found, the callback should use
 *                 \c mbedtls_ssl_set_hs_psk() on the ssl context to set the
 *                 correct PSK and return 0.
 *                 Any other return value will result in a denied PSK identity.
 *
 * \note           If you set a PSK callback using this function, then you
 *                 don't need to set a PSK key and identity using
 *                 \c mbedtls_ssl_conf_psk().
 *
 * \param conf     SSL configuration
 * \param f_psk    PSK identity function
 * \param p_psk    PSK identity parameter
 */

Func mbedtls_ssl_conf_dh_param_bin

int mbedtls_ssl_conf_dh_param_bin( mbedtls_ssl_config *conf,
                                  const unsigned char *dhm_P, size_t P_len,
                                  const unsigned char *dhm_G, size_t G_len );
/**
 * \brief          Set the Diffie-Hellman public P and G values
 *                 from big-endian binary presentations.
 *                 (Default values: MBEDTLS_DHM_RFC3526_MODP_2048_[PG]_BIN)
 *
 * \param conf     SSL configuration
 * \param dhm_P    Diffie-Hellman-Merkle modulus in big-endian binary form
 * \param P_len    Length of DHM modulus
 * \param dhm_G    Diffie-Hellman-Merkle generator in big-endian binary form
 * \param G_len    Length of DHM generator
 *
 * \return         0 if successful
 */

Func mbedtls_ssl_conf_dh_param_ctx

int mbedtls_ssl_conf_dh_param_ctx( mbedtls_ssl_config *conf, mbedtls_dhm_context *dhm_ctx );
/**
 * \brief          Set the Diffie-Hellman public P and G values,
 *                 read from existing context (server-side only)
 *
 * \param conf     SSL configuration
 * \param dhm_ctx  Diffie-Hellman-Merkle context
 *
 * \return         0 if successful
 */

Func mbedtls_ssl_conf_dhm_min_bitlen

void mbedtls_ssl_conf_dhm_min_bitlen( mbedtls_ssl_config *conf,
                                     unsigned int bitlen );
/**
 * \brief          Set the minimum length for Diffie-Hellman parameters.
 *                 (Client-side only.)
 *                 (Default: 1024 bits.)
 *
 * \param conf     SSL configuration
 * \param bitlen   Minimum bit length of the DHM prime
 */

Func mbedtls_ssl_conf_curves

void mbedtls_ssl_conf_curves( mbedtls_ssl_config *conf,
                             const mbedtls_ecp_group_id *curves );
/**
 * \brief          Set the allowed curves in order of preference.
 *                 (Default: all defined curves.)
 *
 *                 On server: this only affects selection of the ECDHE curve;
 *                 the curves used for ECDH and ECDSA are determined by the
 *                 list of available certificates instead.
 *
 *                 On client: this affects the list of curves offered for any
 *                 use. The server can override our preference order.
 *
 *                 Both sides: limits the set of curves accepted for use in
 *                 ECDHE and in the peer's end-entity certificate.
 *
 * \note           This has no influence on which curves are allowed inside the
 *                 certificate chains, see \c mbedtls_ssl_conf_cert_profile()
 *                 for that. For the end-entity certificate however, the key
 *                 will be accepted only if it is allowed both by this list
 *                 and by the cert profile.
 *
 * \note           This list should be ordered by decreasing preference
 *                 (preferred curve first).
 *
 * \param conf     SSL configuration
 * \param curves   Ordered list of allowed curves,
 *                 terminated by MBEDTLS_ECP_DP_NONE.
 */

Func mbedtls_ssl_conf_sig_hashes

void mbedtls_ssl_conf_sig_hashes( mbedtls_ssl_config *conf,
                                 const int *hashes );
/**
 * \brief          Set the allowed hashes for signatures during the handshake.
 *                 (Default: all available hashes except MD5.)
 *
 * \note           This only affects which hashes are offered and can be used
 *                 for signatures during the handshake. Hashes for message
 *                 authentication and the TLS PRF are controlled by the
 *                 ciphersuite, see \c mbedtls_ssl_conf_ciphersuites(). Hashes
 *                 used for certificate signature are controlled by the
 *                 verification profile, see \c mbedtls_ssl_conf_cert_profile().
 *
 * \note           This list should be ordered by decreasing preference
 *                 (preferred hash first).
 *
 * \param conf     SSL configuration
 * \param hashes   Ordered list of allowed signature hashes,
 *                 terminated by \c MBEDTLS_MD_NONE.
 */

Func mbedtls_ssl_set_hostname

int mbedtls_ssl_set_hostname( mbedtls_ssl_context *ssl, const char *hostname );
/**
 * \brief          Set or reset the hostname to check against the received
 *                 server certificate. It sets the ServerName TLS extension,
 *                 too, if that extension is enabled. (client-side only)
 *
 * \param ssl      SSL context
 * \param hostname the server hostname, may be NULL to clear hostname

 * \note           Maximum hostname length MBEDTLS_SSL_MAX_HOST_NAME_LEN.
 *
 * \return         0 if successful, MBEDTLS_ERR_SSL_ALLOC_FAILED on
 *                 allocation failure, MBEDTLS_ERR_SSL_BAD_INPUT_DATA on
 *                 too long input hostname.
 *
 *                 Hostname set to the one provided on success (cleared
 *                 when NULL). On allocation failure hostname is cleared.
 *                 On too long input failure, old hostname is unchanged.
 */

Func mbedtls_ssl_set_hs_own_cert

int mbedtls_ssl_set_hs_own_cert( mbedtls_ssl_context *ssl,
                                mbedtls_x509_crt *own_cert,
                                mbedtls_pk_context *pk_key );
/**
 * \brief          Set own certificate and key for the current handshake
 *
 * \note           Same as \c mbedtls_ssl_conf_own_cert() but for use within
 *                 the SNI callback.
 *
 * \param ssl      SSL context
 * \param own_cert own public certificate chain
 * \param pk_key   own private key
 *
 * \return         0 on success or MBEDTLS_ERR_SSL_ALLOC_FAILED
 */

Func mbedtls_ssl_set_hs_ca_chain

void mbedtls_ssl_set_hs_ca_chain( mbedtls_ssl_context *ssl,
                                 mbedtls_x509_crt *ca_chain,
                                 mbedtls_x509_crl *ca_crl );
/**
 * \brief          Set the data required to verify peer certificate for the
 *                 current handshake
 *
 * \note           Same as \c mbedtls_ssl_conf_ca_chain() but for use within
 *                 the SNI callback.
 *
 * \param ssl      SSL context
 * \param ca_chain trusted CA chain (meaning all fully trusted top-level CAs)
 * \param ca_crl   trusted CA CRLs
 */

Func mbedtls_ssl_set_hs_authmode

void mbedtls_ssl_set_hs_authmode( mbedtls_ssl_context *ssl,
                                 int authmode );
/**
 * \brief          Set authmode for the current handshake.
 *
 * \note           Same as \c mbedtls_ssl_conf_authmode() but for use within
 *                 the SNI callback.
 *
 * \param ssl      SSL context
 * \param authmode MBEDTLS_SSL_VERIFY_NONE, MBEDTLS_SSL_VERIFY_OPTIONAL or
 *                 MBEDTLS_SSL_VERIFY_REQUIRED
 */

Func mbedtls_ssl_conf_sni

void mbedtls_ssl_conf_sni( mbedtls_ssl_config *conf,
                 int (*f_sni)(void *, mbedtls_ssl_context *, const unsigned char *,
                              size_t),
                 void *p_sni );
/**
 * \brief          Set server side ServerName TLS extension callback
 *                 (optional, server-side only).
 *
 *                 If set, the ServerName callback is called whenever the
 *                 server receives a ServerName TLS extension from the client
 *                 during a handshake. The ServerName callback has the
 *                 following parameters: (void *parameter, mbedtls_ssl_context *ssl,
 *                 const unsigned char *hostname, size_t len). If a suitable
 *                 certificate is found, the callback must set the
 *                 certificate(s) and key(s) to use with \c
 *                 mbedtls_ssl_set_hs_own_cert() (can be called repeatedly),
 *                 and may optionally adjust the CA and associated CRL with \c
 *                 mbedtls_ssl_set_hs_ca_chain() as well as the client
 *                 authentication mode with \c mbedtls_ssl_set_hs_authmode(),
 *                 then must return 0. If no matching name is found, the
 *                 callback must either set a default cert, or
 *                 return non-zero to abort the handshake at this point.
 *
 * \param conf     SSL configuration
 * \param f_sni    verification function
 * \param p_sni    verification parameter
 */

Func mbedtls_ssl_set_hs_ecjpake_password

int mbedtls_ssl_set_hs_ecjpake_password( mbedtls_ssl_context *ssl,
                                        const unsigned char *pw,
                                        size_t pw_len );
/**
 * \brief          Set the EC J-PAKE password for current handshake.
 *
 * \note           An internal copy is made, and destroyed as soon as the
 *                 handshake is completed, or when the SSL context is reset or
 *                 freed.
 *
 * \note           The SSL context needs to be already set up. The right place
 *                 to call this function is between \c mbedtls_ssl_setup() or
 *                 \c mbedtls_ssl_reset() and \c mbedtls_ssl_handshake().
 *
 * \param ssl      SSL context
 * \param pw       EC J-PAKE password (pre-shared secret)
 * \param pw_len   length of pw in bytes
 *
 * \return         0 on success, or a negative error code.
 */

Func mbedtls_ssl_conf_alpn_protocols

int mbedtls_ssl_conf_alpn_protocols( mbedtls_ssl_config *conf, const char **protos );
/**
 * \brief          Set the supported Application Layer Protocols.
 *
 * \param conf     SSL configuration
 * \param protos   Pointer to a NULL-terminated list of supported protocols,
 *                 in decreasing preference order. The pointer to the list is
 *                 recorded by the library for later reference as required, so
 *                 the lifetime of the table must be atleast as long as the
 *                 lifetime of the SSL configuration structure.
 *
 * \return         0 on success, or MBEDTLS_ERR_SSL_BAD_INPUT_DATA.
 */

Func mbedtls_ssl_conf_srtp_mki_value_supported

void mbedtls_ssl_conf_srtp_mki_value_supported( mbedtls_ssl_config *conf,
                                               int support_mki_value );
/**
 * \brief                   Add support for mki value in use_srtp extension
 *                          (Default: MBEDTLS_SSL_DTLS_SRTP_MKI_UNSUPPORTED)
 *
 * \param conf              SSL configuration
 * \param support_mki_value Enable or disable (MBEDTLS_SSL_DTLS_SRTP_MKI_UNSUPPORTED
 *                          or MBEDTLS_SSL_DTLS_SRTP_MKI_SUPPORTED)
 */

Func mbedtls_ssl_conf_dtls_srtp_protection_profiles

int mbedtls_ssl_conf_dtls_srtp_protection_profiles( mbedtls_ssl_config *conf,
                                                   const mbedtls_ssl_srtp_profile *profiles,
                                                   size_t profiles_number );
/**
 * \brief                   Set the supported DTLS-SRTP protection profiles.
 *
 * \param conf              SSL configuration
 * \param profiles          List of supported protection profiles,
 *                          in decreasing preference order.
 * \param profiles_number   Number of supported profiles.
 *
 * \return         0 on success, or MBEDTLS_ERR_SSL_BAD_INPUT_DATA.
 */

Func mbedtls_ssl_dtls_srtp_set_mki_value

int mbedtls_ssl_dtls_srtp_set_mki_value( mbedtls_ssl_context *ssl,
                                        unsigned char *mki_value,
                                        size_t mki_len );
/**
 * \brief                   Set the mki_value for the current dtls session.
 *
 * \param ssl              SSL context
 * \param mki_value        MKI value to set
 * \param mki_len          MKI length
 *
 * \return         0 on success, MBEDTLS_ERR_SSL_BAD_INPUT_DATA
 *                 or MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE on failure
 */

Func mbedtls_ssl_get_dtls_srtp_key_material

int mbedtls_ssl_get_dtls_srtp_key_material( const mbedtls_ssl_context *ssl,
                                           unsigned char *key,
                                           size_t *key_len );
/**
 * \brief                  Get the generated DTLS-SRTP key material.
 *                         This function should be called after the handshake is
 *                         completed. It shall returns 80 bytes of key material
 *                         generated according to RFC5764
 *
 * \param ssl              SSL context
 * \param key              Buffer to hold the generated key material
 * \param key_len          [in/out] key buffer size. outputs the actual number
 *                         of bytes written
 *
 * \return         0 on succes, MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL if the key buffer
 *                 is too small to hold the generated key
 */

Func mbedtls_ssl_conf_max_version

void mbedtls_ssl_conf_max_version( mbedtls_ssl_config *conf, int major, int minor );
/**
 * \brief          Set the maximum supported version sent from the client side
 *                 and/or accepted at the server side
 *                 (Default: MBEDTLS_SSL_MAX_MAJOR_VERSION, MBEDTLS_SSL_MAX_MINOR_VERSION)
 *
 * \note           This ignores ciphersuites from higher versions.
 *
 * \note           With DTLS, use MBEDTLS_SSL_MINOR_VERSION_2 for DTLS 1.0 and
 *                 MBEDTLS_SSL_MINOR_VERSION_3 for DTLS 1.2
 *
 * \param conf     SSL configuration
 * \param major    Major version number (only MBEDTLS_SSL_MAJOR_VERSION_3 supported)
 * \param minor    Minor version number (MBEDTLS_SSL_MINOR_VERSION_0,
 *                 MBEDTLS_SSL_MINOR_VERSION_1 and MBEDTLS_SSL_MINOR_VERSION_2,
 *                 MBEDTLS_SSL_MINOR_VERSION_3 supported)
 */

Func mbedtls_ssl_conf_min_version

void mbedtls_ssl_conf_min_version( mbedtls_ssl_config *conf, int major, int minor );
/**
 * \brief          Set the minimum accepted SSL/TLS protocol version
 *                 (Default: TLS 1.0)
 *
 * \note           Input outside of the SSL_MAX_XXXXX_VERSION and
 *                 SSL_MIN_XXXXX_VERSION range is ignored.
 *
 * \note           MBEDTLS_SSL_MINOR_VERSION_0 (SSL v3) should be avoided.
 *
 * \note           With DTLS, use MBEDTLS_SSL_MINOR_VERSION_2 for DTLS 1.0 and
 *                 MBEDTLS_SSL_MINOR_VERSION_3 for DTLS 1.2
 *
 * \param conf     SSL configuration
 * \param major    Major version number (only MBEDTLS_SSL_MAJOR_VERSION_3 supported)
 * \param minor    Minor version number (MBEDTLS_SSL_MINOR_VERSION_0,
 *                 MBEDTLS_SSL_MINOR_VERSION_1 and MBEDTLS_SSL_MINOR_VERSION_2,
 *                 MBEDTLS_SSL_MINOR_VERSION_3 supported)
 */

Func mbedtls_ssl_conf_fallback

void mbedtls_ssl_conf_fallback( mbedtls_ssl_config *conf, char fallback );
/**
 * \brief          Set the fallback flag (client-side only).
 *                 (Default: MBEDTLS_SSL_IS_NOT_FALLBACK).
 *
 * \note           Set to MBEDTLS_SSL_IS_FALLBACK when preparing a fallback
 *                 connection, that is a connection with max_version set to a
 *                 lower value than the value you're willing to use. Such
 *                 fallback connections are not recommended but are sometimes
 *                 necessary to interoperate with buggy (version-intolerant)
 *                 servers.
 *
 * \warning        You should NOT set this to MBEDTLS_SSL_IS_FALLBACK for
 *                 non-fallback connections! This would appear to work for a
 *                 while, then cause failures when the server is upgraded to
 *                 support a newer TLS version.
 *
 * \param conf     SSL configuration
 * \param fallback MBEDTLS_SSL_IS_NOT_FALLBACK or MBEDTLS_SSL_IS_FALLBACK
 */

Func mbedtls_ssl_conf_encrypt_then_mac

void mbedtls_ssl_conf_encrypt_then_mac( mbedtls_ssl_config *conf, char etm );
/**
 * \brief           Enable or disable Encrypt-then-MAC
 *                  (Default: MBEDTLS_SSL_ETM_ENABLED)
 *
 * \note            This should always be enabled, it is a security
 *                  improvement, and should not cause any interoperability
 *                  issue (used only if the peer supports it too).
 *
 * \param conf      SSL configuration
 * \param etm       MBEDTLS_SSL_ETM_ENABLED or MBEDTLS_SSL_ETM_DISABLED
 */

Func mbedtls_ssl_conf_extended_master_secret

void mbedtls_ssl_conf_extended_master_secret( mbedtls_ssl_config *conf, char ems );
/**
 * \brief           Enable or disable Extended Master Secret negotiation.
 *                  (Default: MBEDTLS_SSL_EXTENDED_MS_ENABLED)
 *
 * \note            This should always be enabled, it is a security fix to the
 *                  protocol, and should not cause any interoperability issue
 *                  (used only if the peer supports it too).
 *
 * \param conf      SSL configuration
 * \param ems       MBEDTLS_SSL_EXTENDED_MS_ENABLED or MBEDTLS_SSL_EXTENDED_MS_DISABLED
 */

Func mbedtls_ssl_conf_arc4_support

void mbedtls_ssl_conf_arc4_support( mbedtls_ssl_config *conf, char arc4 );
/**
 * \brief          Disable or enable support for RC4
 *                 (Default: MBEDTLS_SSL_ARC4_DISABLED)
 *
 * \warning        Use of RC4 in DTLS/TLS has been prohibited by RFC 7465
 *                 for security reasons. Use at your own risk.
 *
 * \note           This function is deprecated and will likely be removed in
 *                 a future version of the library.
 *                 RC4 is disabled by default at compile time and needs to be
 *                 actively enabled for use with legacy systems.
 *
 * \param conf     SSL configuration
 * \param arc4     MBEDTLS_SSL_ARC4_ENABLED or MBEDTLS_SSL_ARC4_DISABLED
 */

Func mbedtls_ssl_conf_cert_req_ca_list

void mbedtls_ssl_conf_cert_req_ca_list( mbedtls_ssl_config *conf,
                                         char cert_req_ca_list );
/**
 * \brief          Whether to send a list of acceptable CAs in
 *                 CertificateRequest messages.
 *                 (Default: do send)
 *
 * \param conf     SSL configuration
 * \param cert_req_ca_list   MBEDTLS_SSL_CERT_REQ_CA_LIST_ENABLED or
 *                          MBEDTLS_SSL_CERT_REQ_CA_LIST_DISABLED
 */

Func mbedtls_ssl_conf_max_frag_len

int mbedtls_ssl_conf_max_frag_len( mbedtls_ssl_config *conf, unsigned char mfl_code );
/**
 * \brief          Set the maximum fragment length to emit and/or negotiate.
 *                 (Typical: the smaller of #MBEDTLS_SSL_IN_CONTENT_LEN and
 *                 #MBEDTLS_SSL_OUT_CONTENT_LEN, usually `2^14` bytes)
 *                 (Server: set maximum fragment length to emit,
 *                 usually negotiated by the client during handshake)
 *                 (Client: set maximum fragment length to emit *and*
 *                 negotiate with the server during handshake)
 *                 (Default: #MBEDTLS_SSL_MAX_FRAG_LEN_NONE)
 *
 * \note           On the client side, the maximum fragment length extension
 *                 *will not* be used, unless the maximum fragment length has
 *                 been set via this function to a value different than
 *                 #MBEDTLS_SSL_MAX_FRAG_LEN_NONE.
 *
 * \note           This sets the maximum length for a record's payload,
 *                 excluding record overhead that will be added to it, see
 *                 \c mbedtls_ssl_get_record_expansion().
 *
 * \note           With TLS, this currently only affects ApplicationData (sent
 *                 with \c mbedtls_ssl_read()), not handshake messages.
 *                 With DTLS, this affects both ApplicationData and handshake.
 *
 * \note           For DTLS, it is also possible to set a limit for the total
 *                 size of daragrams passed to the transport layer, including
 *                 record overhead, see \c mbedtls_ssl_set_mtu().
 *
 * \param conf     SSL configuration
 * \param mfl_code Code for maximum fragment length (allowed values:
 *                 MBEDTLS_SSL_MAX_FRAG_LEN_512,  MBEDTLS_SSL_MAX_FRAG_LEN_1024,
 *                 MBEDTLS_SSL_MAX_FRAG_LEN_2048, MBEDTLS_SSL_MAX_FRAG_LEN_4096)
 *
 * \return         0 if successful or MBEDTLS_ERR_SSL_BAD_INPUT_DATA
 */

Func mbedtls_ssl_conf_truncated_hmac

void mbedtls_ssl_conf_truncated_hmac( mbedtls_ssl_config *conf, int truncate );
/**
 * \brief          Activate negotiation of truncated HMAC
 *                 (Default: MBEDTLS_SSL_TRUNC_HMAC_DISABLED)
 *
 * \param conf     SSL configuration
 * \param truncate Enable or disable (MBEDTLS_SSL_TRUNC_HMAC_ENABLED or
 *                                    MBEDTLS_SSL_TRUNC_HMAC_DISABLED)
 */

Func mbedtls_ssl_conf_cbc_record_splitting

void mbedtls_ssl_conf_cbc_record_splitting( mbedtls_ssl_config *conf, char split );
/**
 * \brief          Enable / Disable 1/n-1 record splitting
 *                 (Default: MBEDTLS_SSL_CBC_RECORD_SPLITTING_ENABLED)
 *
 * \note           Only affects SSLv3 and TLS 1.0, not higher versions.
 *                 Does not affect non-CBC ciphersuites in any version.
 *
 * \param conf     SSL configuration
 * \param split    MBEDTLS_SSL_CBC_RECORD_SPLITTING_ENABLED or
 *                 MBEDTLS_SSL_CBC_RECORD_SPLITTING_DISABLED
 */

Func mbedtls_ssl_conf_session_tickets

void mbedtls_ssl_conf_session_tickets( mbedtls_ssl_config *conf, int use_tickets );
/**
 * \brief          Enable / Disable session tickets (client only).
 *                 (Default: MBEDTLS_SSL_SESSION_TICKETS_ENABLED.)
 *
 * \note           On server, use \c mbedtls_ssl_conf_session_tickets_cb().
 *
 * \param conf     SSL configuration
 * \param use_tickets   Enable or disable (MBEDTLS_SSL_SESSION_TICKETS_ENABLED or
 *                                         MBEDTLS_SSL_SESSION_TICKETS_DISABLED)
 */

Func mbedtls_ssl_conf_renegotiation

void mbedtls_ssl_conf_renegotiation( mbedtls_ssl_config *conf, int renegotiation );
/**
 * \brief          Enable / Disable renegotiation support for connection when
 *                 initiated by peer
 *                 (Default: MBEDTLS_SSL_RENEGOTIATION_DISABLED)
 *
 * \warning        It is recommended to always disable renegotation unless you
 *                 know you need it and you know what you're doing. In the
 *                 past, there have been several issues associated with
 *                 renegotiation or a poor understanding of its properties.
 *
 * \note           Server-side, enabling renegotiation also makes the server
 *                 susceptible to a resource DoS by a malicious client.
 *
 * \param conf    SSL configuration
 * \param renegotiation     Enable or disable (MBEDTLS_SSL_RENEGOTIATION_ENABLED or
 *                                             MBEDTLS_SSL_RENEGOTIATION_DISABLED)
 */

Func mbedtls_ssl_conf_legacy_renegotiation

void mbedtls_ssl_conf_legacy_renegotiation( mbedtls_ssl_config *conf, int allow_legacy );
/**
 * \brief          Prevent or allow legacy renegotiation.
 *                 (Default: MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION)
 *
 *                 MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION allows connections to
 *                 be established even if the peer does not support
 *                 secure renegotiation, but does not allow renegotiation
 *                 to take place if not secure.
 *                 (Interoperable and secure option)
 *
 *                 MBEDTLS_SSL_LEGACY_ALLOW_RENEGOTIATION allows renegotiations
 *                 with non-upgraded peers. Allowing legacy renegotiation
 *                 makes the connection vulnerable to specific man in the
 *                 middle attacks. (See RFC 5746)
 *                 (Most interoperable and least secure option)
 *
 *                 MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE breaks off connections
 *                 if peer does not support secure renegotiation. Results
 *                 in interoperability issues with non-upgraded peers
 *                 that do not support renegotiation altogether.
 *                 (Most secure option, interoperability issues)
 *
 * \param conf     SSL configuration
 * \param allow_legacy  Prevent or allow (SSL_NO_LEGACY_RENEGOTIATION,
 *                                        SSL_ALLOW_LEGACY_RENEGOTIATION or
 *                                        MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE)
 */

Func mbedtls_ssl_conf_renegotiation_enforced

void mbedtls_ssl_conf_renegotiation_enforced( mbedtls_ssl_config *conf, int max_records );
/**
 * \brief          Enforce renegotiation requests.
 *                 (Default: enforced, max_records = 16)
 *
 *                 When we request a renegotiation, the peer can comply or
 *                 ignore the request. This function allows us to decide
 *                 whether to enforce our renegotiation requests by closing
 *                 the connection if the peer doesn't comply.
 *
 *                 However, records could already be in transit from the peer
 *                 when the request is emitted. In order to increase
 *                 reliability, we can accept a number of records before the
 *                 expected handshake records.
 *
 *                 The optimal value is highly dependent on the specific usage
 *                 scenario.
 *
 * \note           With DTLS and server-initiated renegotiation, the
 *                 HelloRequest is retransmited every time mbedtls_ssl_read() times
 *                 out or receives Application Data, until:
 *                 - max_records records have beens seen, if it is >= 0, or
 *                 - the number of retransmits that would happen during an
 *                 actual handshake has been reached.
 *                 Please remember the request might be lost a few times
 *                 if you consider setting max_records to a really low value.
 *
 * \warning        On client, the grace period can only happen during
 *                 mbedtls_ssl_read(), as opposed to mbedtls_ssl_write() and mbedtls_ssl_renegotiate()
 *                 which always behave as if max_record was 0. The reason is,
 *                 if we receive application data from the server, we need a
 *                 place to write it, which only happens during mbedtls_ssl_read().
 *
 * \param conf     SSL configuration
 * \param max_records Use MBEDTLS_SSL_RENEGOTIATION_NOT_ENFORCED if you don't want to
 *                 enforce renegotiation, or a non-negative value to enforce
 *                 it but allow for a grace period of max_records records.
 */

Func mbedtls_ssl_conf_renegotiation_period

void mbedtls_ssl_conf_renegotiation_period( mbedtls_ssl_config *conf,
                                  const unsigned char period[8] );
/**
 * \brief          Set record counter threshold for periodic renegotiation.
 *                 (Default: 2^48 - 1)
 *
 *                 Renegotiation is automatically triggered when a record
 *                 counter (outgoing or ingoing) crosses the defined
 *                 threshold. The default value is meant to prevent the
 *                 connection from being closed when the counter is about to
 *                 reached its maximal value (it is not allowed to wrap).
 *
 *                 Lower values can be used to enforce policies such as "keys
 *                 must be refreshed every N packets with cipher X".
 *
 *                 The renegotiation period can be disabled by setting
 *                 conf->disable_renegotiation to
 *                 MBEDTLS_SSL_RENEGOTIATION_DISABLED.
 *
 * \note           When the configured transport is
 *                 MBEDTLS_SSL_TRANSPORT_DATAGRAM the maximum renegotiation
 *                 period is 2^48 - 1, and for MBEDTLS_SSL_TRANSPORT_STREAM,
 *                 the maximum renegotiation period is 2^64 - 1.
 *
 * \param conf     SSL configuration
 * \param period   The threshold value: a big-endian 64-bit number.
 */

Func mbedtls_ssl_check_pending

int mbedtls_ssl_check_pending( const mbedtls_ssl_context *ssl );
/**
 * \brief          Check if there is data already read from the
 *                 underlying transport but not yet processed.
 *
 * \param ssl      SSL context
 *
 * \return         0 if nothing's pending, 1 otherwise.
 *
 * \note           This is different in purpose and behaviour from
 *                 \c mbedtls_ssl_get_bytes_avail in that it considers
 *                 any kind of unprocessed data, not only unread
 *                 application data. If \c mbedtls_ssl_get_bytes
 *                 returns a non-zero value, this function will
 *                 also signal pending data, but the converse does
 *                 not hold. For example, in DTLS there might be
 *                 further records waiting to be processed from
 *                 the current underlying transport's datagram.
 *
 * \note           If this function returns 1 (data pending), this
 *                 does not imply that a subsequent call to
 *                 \c mbedtls_ssl_read will provide any data;
 *                 e.g., the unprocessed data might turn out
 *                 to be an alert or a handshake message.
 *
 * \note           This function is useful in the following situation:
 *                 If the SSL/TLS module successfully returns from an
 *                 operation - e.g. a handshake or an application record
 *                 read - and you're awaiting incoming data next, you
 *                 must not immediately idle on the underlying transport
 *                 to have data ready, but you need to check the value
 *                 of this function first. The reason is that the desired
 *                 data might already be read but not yet processed.
 *                 If, in contrast, a previous call to the SSL/TLS module
 *                 returned MBEDTLS_ERR_SSL_WANT_READ, it is not necessary
 *                 to call this function, as the latter error code entails
 *                 that all internal data has been processed.
 *
 */

Func mbedtls_ssl_get_bytes_avail

size_t mbedtls_ssl_get_bytes_avail( const mbedtls_ssl_context *ssl );
/**
 * \brief          Return the number of application data bytes
 *                 remaining to be read from the current record.
 *
 * \param ssl      SSL context
 *
 * \return         How many bytes are available in the application
 *                 data record read buffer.
 *
 * \note           When working over a datagram transport, this is
 *                 useful to detect the current datagram's boundary
 *                 in case \c mbedtls_ssl_read has written the maximal
 *                 amount of data fitting into the input buffer.
 *
 */

Func mbedtls_ssl_get_verify_result

uint32_t mbedtls_ssl_get_verify_result( const mbedtls_ssl_context *ssl );
/**
 * \brief          Return the result of the certificate verification
 *
 * \param ssl      The SSL context to use.
 *
 * \return         \c 0 if the certificate verification was successful.
 * \return         \c -1u if the result is not available. This may happen
 *                 e.g. if the handshake aborts early, or a verification
 *                 callback returned a fatal error.
 * \return         A bitwise combination of \c MBEDTLS_X509_BADCERT_XXX
 *                 and \c MBEDTLS_X509_BADCRL_XXX failure flags; see x509.h.
 */

Func mbedtls_ssl_get_record_expansion

int mbedtls_ssl_get_record_expansion( const mbedtls_ssl_context *ssl );
/**
 * \brief          Return the (maximum) number of bytes added by the record
 *                 layer: header + encryption/MAC overhead (inc. padding)
 *
 * \note           This function is not available (always returns an error)
 *                 when record compression is enabled.
 *
 * \param ssl      SSL context
 *
 * \return         Current maximum record expansion in bytes, or
 *                 MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE if compression is
 *                 enabled, which makes expansion much less predictable
 */

Func mbedtls_ssl_get_max_frag_len

size_t mbedtls_ssl_get_max_frag_len( const mbedtls_ssl_context *ssl );
/**
 * \brief          Return the maximum fragment length (payload, in bytes).
 *                 This is the value negotiated with peer if any,
 *                 or the locally configured value.
 *
 * \sa             mbedtls_ssl_conf_max_frag_len()
 * \sa             mbedtls_ssl_get_max_record_payload()
 *
 * \param ssl      SSL context
 *
 * \return         Current maximum fragment length.
 */

Func mbedtls_ssl_get_max_out_record_payload

int mbedtls_ssl_get_max_out_record_payload( const mbedtls_ssl_context *ssl );
/**
 * \brief          Return the current maximum outgoing record payload in bytes.
 *                 This takes into account the config.h setting \c
 *                 MBEDTLS_SSL_OUT_CONTENT_LEN, the configured and negotiated
 *                 max fragment length extension if used, and for DTLS the
 *                 path MTU as configured and current record expansion.
 *
 * \note           With DTLS, \c mbedtls_ssl_write() will return an error if
 *                 called with a larger length value.
 *                 With TLS, \c mbedtls_ssl_write() will fragment the input if
 *                 necessary and return the number of bytes written; it is up
 *                 to the caller to call \c mbedtls_ssl_write() again in
 *                 order to send the remaining bytes if any.
 *
 * \note           This function is not available (always returns an error)
 *                 when record compression is enabled.
 *
 * \sa             mbedtls_ssl_set_mtu()
 * \sa             mbedtls_ssl_get_max_frag_len()
 * \sa             mbedtls_ssl_get_record_expansion()
 *
 * \param ssl      SSL context
 *
 * \return         Current maximum payload for an outgoing record,
 *                 or a negative error code.
 */

Func mbedtls_ssl_get_session

int mbedtls_ssl_get_session( const mbedtls_ssl_context *ssl, mbedtls_ssl_session *session );
/**
 * \brief          Save session in order to resume it later (client-side only)
 *                 Session data is copied to presented session structure.
 *
 *
 * \param ssl      SSL context
 * \param session  session context
 *
 * \return         0 if successful,
 *                 MBEDTLS_ERR_SSL_ALLOC_FAILED if memory allocation failed,
 *                 MBEDTLS_ERR_SSL_BAD_INPUT_DATA if used server-side or
 *                 arguments are otherwise invalid.
 *
 * \note           Only the server certificate is copied, and not the full chain,
 *                 so you should not attempt to validate the certificate again
 *                 by calling \c mbedtls_x509_crt_verify() on it.
 *                 Instead, you should use the results from the verification
 *                 in the original handshake by calling \c mbedtls_ssl_get_verify_result()
 *                 after loading the session again into a new SSL context
 *                 using \c mbedtls_ssl_set_session().
 *
 * \note           Once the session object is not needed anymore, you should
 *                 free it by calling \c mbedtls_ssl_session_free().
 *
 * \sa             mbedtls_ssl_set_session()
 */

Func mbedtls_ssl_handshake

int mbedtls_ssl_handshake( mbedtls_ssl_context *ssl );
/**
 * \brief          Perform the SSL handshake
 *
 * \param ssl      SSL context
 *
 * \return         \c 0 if successful.
 * \return         #MBEDTLS_ERR_SSL_WANT_READ or #MBEDTLS_ERR_SSL_WANT_WRITE
 *                 if the handshake is incomplete and waiting for data to
 *                 be available for reading from or writing to the underlying
 *                 transport - in this case you must call this function again
 *                 when the underlying transport is ready for the operation.
 * \return         #MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS if an asynchronous
 *                 operation is in progress (see
 *                 mbedtls_ssl_conf_async_private_cb()) - in this case you
 *                 must call this function again when the operation is ready.
 * \return         #MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS if a cryptographic
 *                 operation is in progress (see mbedtls_ecp_set_max_ops()) -
 *                 in this case you must call this function again to complete
 *                 the handshake when you're done attending other tasks.
 * \return         #MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED if DTLS is in use
 *                 and the client did not demonstrate reachability yet - in
 *                 this case you must stop using the context (see below).
 * \return         Another SSL error code - in this case you must stop using
 *                 the context (see below).
 *
 * \warning        If this function returns something other than
 *                 \c 0,
 *                 #MBEDTLS_ERR_SSL_WANT_READ,
 *                 #MBEDTLS_ERR_SSL_WANT_WRITE,
 *                 #MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS or
 *                 #MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS,
 *                 you must stop using the SSL context for reading or writing,
 *                 and either free it or call \c mbedtls_ssl_session_reset()
 *                 on it before re-using it for a new connection; the current
 *                 connection must be closed.
 *
 * \note           If DTLS is in use, then you may choose to handle
 *                 #MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED specially for logging
 *                 purposes, as it is an expected return value rather than an
 *                 actual error, but you still need to reset/free the context.
 *
 * \note           Remarks regarding event-driven DTLS:
 *                 If the function returns #MBEDTLS_ERR_SSL_WANT_READ, no datagram
 *                 from the underlying transport layer is currently being processed,
 *                 and it is safe to idle until the timer or the underlying transport
 *                 signal a new event. This is not true for a successful handshake,
 *                 in which case the datagram of the underlying transport that is
 *                 currently being processed might or might not contain further
 *                 DTLS records.
 */

Func mbedtls_ssl_handshake_step

int mbedtls_ssl_handshake_step( mbedtls_ssl_context *ssl );
/**
 * \brief          Perform a single step of the SSL handshake
 *
 * \note           The state of the context (ssl->state) will be at
 *                 the next state after this function returns \c 0. Do not
 *                 call this function if state is MBEDTLS_SSL_HANDSHAKE_OVER.
 *
 * \param ssl      SSL context
 *
 * \return         See mbedtls_ssl_handshake().
 *
 * \warning        If this function returns something other than \c 0,
 *                 #MBEDTLS_ERR_SSL_WANT_READ, #MBEDTLS_ERR_SSL_WANT_WRITE,
 *                 #MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS or
 *                 #MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS, you must stop using
 *                 the SSL context for reading or writing, and either free it
 *                 or call \c mbedtls_ssl_session_reset() on it before
 *                 re-using it for a new connection; the current connection
 *                 must be closed.
 */

Func mbedtls_ssl_renegotiate

int mbedtls_ssl_renegotiate( mbedtls_ssl_context *ssl );
/**
 * \brief          Initiate an SSL renegotiation on the running connection.
 *                 Client: perform the renegotiation right now.
 *                 Server: request renegotiation, which will be performed
 *                 during the next call to mbedtls_ssl_read() if honored by
 *                 client.
 *
 * \param ssl      SSL context
 *
 * \return         0 if successful, or any mbedtls_ssl_handshake() return
 *                 value except #MBEDTLS_ERR_SSL_CLIENT_RECONNECT that can't
 *                 happen during a renegotiation.
 *
 * \warning        If this function returns something other than \c 0,
 *                 #MBEDTLS_ERR_SSL_WANT_READ, #MBEDTLS_ERR_SSL_WANT_WRITE,
 *                 #MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS or
 *                 #MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS, you must stop using
 *                 the SSL context for reading or writing, and either free it
 *                 or call \c mbedtls_ssl_session_reset() on it before
 *                 re-using it for a new connection; the current connection
 *                 must be closed.
 *
 */

Func mbedtls_ssl_read

int mbedtls_ssl_read( mbedtls_ssl_context *ssl, unsigned char *buf, size_t len );
/**
 * \brief          Read at most 'len' application data bytes
 *
 * \param ssl      SSL context
 * \param buf      buffer that will hold the data
 * \param len      maximum number of bytes to read
 *
 * \return         The (positive) number of bytes read if successful.
 * \return         \c 0 if the read end of the underlying transport was closed
 *                 - in this case you must stop using the context (see below).
 * \return         #MBEDTLS_ERR_SSL_WANT_READ or #MBEDTLS_ERR_SSL_WANT_WRITE
 *                 if the handshake is incomplete and waiting for data to
 *                 be available for reading from or writing to the underlying
 *                 transport - in this case you must call this function again
 *                 when the underlying transport is ready for the operation.
 * \return         #MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS if an asynchronous
 *                 operation is in progress (see
 *                 mbedtls_ssl_conf_async_private_cb()) - in this case you
 *                 must call this function again when the operation is ready.
 * \return         #MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS if a cryptographic
 *                 operation is in progress (see mbedtls_ecp_set_max_ops()) -
 *                 in this case you must call this function again to complete
 *                 the handshake when you're done attending other tasks.
 * \return         #MBEDTLS_ERR_SSL_CLIENT_RECONNECT if we're at the server
 *                 side of a DTLS connection and the client is initiating a
 *                 new connection using the same source port. See below.
 * \return         Another SSL error code - in this case you must stop using
 *                 the context (see below).
 *
 * \warning        If this function returns something other than
 *                 a positive value,
 *                 #MBEDTLS_ERR_SSL_WANT_READ,
 *                 #MBEDTLS_ERR_SSL_WANT_WRITE,
 *                 #MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS,
 *                 #MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS or
 *                 #MBEDTLS_ERR_SSL_CLIENT_RECONNECT,
 *                 you must stop using the SSL context for reading or writing,
 *                 and either free it or call \c mbedtls_ssl_session_reset()
 *                 on it before re-using it for a new connection; the current
 *                 connection must be closed.
 *
 * \note           When this function returns #MBEDTLS_ERR_SSL_CLIENT_RECONNECT
 *                 (which can only happen server-side), it means that a client
 *                 is initiating a new connection using the same source port.
 *                 You can either treat that as a connection close and wait
 *                 for the client to resend a ClientHello, or directly
 *                 continue with \c mbedtls_ssl_handshake() with the same
 *                 context (as it has been reset internally). Either way, you
 *                 must make sure this is seen by the application as a new
 *                 connection: application state, if any, should be reset, and
 *                 most importantly the identity of the client must be checked
 *                 again. WARNING: not validating the identity of the client
 *                 again, or not transmitting the new identity to the
 *                 application layer, would allow authentication bypass!
 *
 * \note           Remarks regarding event-driven DTLS:
 *                 - If the function returns #MBEDTLS_ERR_SSL_WANT_READ, no datagram
 *                   from the underlying transport layer is currently being processed,
 *                   and it is safe to idle until the timer or the underlying transport
 *                   signal a new event.
 *                 - This function may return MBEDTLS_ERR_SSL_WANT_READ even if data was
 *                   initially available on the underlying transport, as this data may have
 *                   been only e.g. duplicated messages or a renegotiation request.
 *                   Therefore, you must be prepared to receive MBEDTLS_ERR_SSL_WANT_READ even
 *                   when reacting to an incoming-data event from the underlying transport.
 *                 - On success, the datagram of the underlying transport that is currently
 *                   being processed may contain further DTLS records. You should call
 *                   \c mbedtls_ssl_check_pending to check for remaining records.
 *
 */

Func mbedtls_ssl_write

int mbedtls_ssl_write( mbedtls_ssl_context *ssl, const unsigned char *buf, size_t len );
/**
 * \brief          Try to write exactly 'len' application data bytes
 *
 * \warning        This function will do partial writes in some cases. If the
 *                 return value is non-negative but less than length, the
 *                 function must be called again with updated arguments:
 *                 buf + ret, len - ret (if ret is the return value) until
 *                 it returns a value equal to the last 'len' argument.
 *
 * \param ssl      SSL context
 * \param buf      buffer holding the data
 * \param len      how many bytes must be written
 *
 * \return         The (non-negative) number of bytes actually written if
 *                 successful (may be less than \p len).
 * \return         #MBEDTLS_ERR_SSL_WANT_READ or #MBEDTLS_ERR_SSL_WANT_WRITE
 *                 if the handshake is incomplete and waiting for data to
 *                 be available for reading from or writing to the underlying
 *                 transport - in this case you must call this function again
 *                 when the underlying transport is ready for the operation.
 * \return         #MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS if an asynchronous
 *                 operation is in progress (see
 *                 mbedtls_ssl_conf_async_private_cb()) - in this case you
 *                 must call this function again when the operation is ready.
 * \return         #MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS if a cryptographic
 *                 operation is in progress (see mbedtls_ecp_set_max_ops()) -
 *                 in this case you must call this function again to complete
 *                 the handshake when you're done attending other tasks.
 * \return         Another SSL error code - in this case you must stop using
 *                 the context (see below).
 *
 * \warning        If this function returns something other than
 *                 a non-negative value,
 *                 #MBEDTLS_ERR_SSL_WANT_READ,
 *                 #MBEDTLS_ERR_SSL_WANT_WRITE,
 *                 #MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS or
 *                 #MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS,
 *                 you must stop using the SSL context for reading or writing,
 *                 and either free it or call \c mbedtls_ssl_session_reset()
 *                 on it before re-using it for a new connection; the current
 *                 connection must be closed.
 *
 * \note           When this function returns #MBEDTLS_ERR_SSL_WANT_WRITE/READ,
 *                 it must be called later with the *same* arguments,
 *                 until it returns a value greater that or equal to 0. When
 *                 the function returns #MBEDTLS_ERR_SSL_WANT_WRITE there may be
 *                 some partial data in the output buffer, however this is not
 *                 yet sent.
 *
 * \note           If the requested length is greater than the maximum
 *                 fragment length (either the built-in limit or the one set
 *                 or negotiated with the peer), then:
 *                 - with TLS, less bytes than requested are written.
 *                 - with DTLS, MBEDTLS_ERR_SSL_BAD_INPUT_DATA is returned.
 *                 \c mbedtls_ssl_get_max_frag_len() may be used to query the
 *                 active maximum fragment length.
 *
 * \note           Attempting to write 0 bytes will result in an empty TLS
 *                 application record being sent.
 */

Func mbedtls_ssl_send_alert_message

int mbedtls_ssl_send_alert_message( mbedtls_ssl_context *ssl,
                           unsigned char level,
                           unsigned char message );
/**
 * \brief           Send an alert message
 *
 * \param ssl       SSL context
 * \param level     The alert level of the message
 *                  (MBEDTLS_SSL_ALERT_LEVEL_WARNING or MBEDTLS_SSL_ALERT_LEVEL_FATAL)
 * \param message   The alert message (SSL_ALERT_MSG_*)
 *
 * \return          0 if successful, or a specific SSL error code.
 *
 * \note           If this function returns something other than 0 or
 *                 MBEDTLS_ERR_SSL_WANT_READ/WRITE, you must stop using
 *                 the SSL context for reading or writing, and either free it or
 *                 call \c mbedtls_ssl_session_reset() on it before re-using it
 *                 for a new connection; the current connection must be closed.
 */

Func mbedtls_ssl_close_notify

int mbedtls_ssl_close_notify( mbedtls_ssl_context *ssl );
/**
 * \brief          Notify the peer that the connection is being closed
 *
 * \param ssl      SSL context
 *
 * \return          0 if successful, or a specific SSL error code.
 *
 * \note           If this function returns something other than 0 or
 *                 MBEDTLS_ERR_SSL_WANT_READ/WRITE, you must stop using
 *                 the SSL context for reading or writing, and either free it or
 *                 call \c mbedtls_ssl_session_reset() on it before re-using it
 *                 for a new connection; the current connection must be closed.
 */

Func mbedtls_ssl_free

void mbedtls_ssl_free( mbedtls_ssl_context *ssl );
/**
 * \brief          Free referenced items in an SSL context and clear memory
 *
 * \param ssl      SSL context
 */

Func mbedtls_ssl_free_session_negotiate_peer_cert

void mbedtls_ssl_free_session_negotiate_peer_cert( mbedtls_ssl_context *ssl );


      

Func mbedtls_ssl_config_init

void mbedtls_ssl_config_init( mbedtls_ssl_config *conf );
/**
 * \brief          Initialize an SSL configuration context
 *                 Just makes the context ready for
 *                 mbedtls_ssl_config_defaults() or mbedtls_ssl_config_free().
 *
 * \note           You need to call mbedtls_ssl_config_defaults() unless you
 *                 manually set all of the relevent fields yourself.
 *
 * \param conf     SSL configuration context
 */

Func mbedtls_ssl_config_defaults

int mbedtls_ssl_config_defaults( mbedtls_ssl_config *conf,
                                int endpoint, int transport, int preset );
/**
 * \brief          Load reasonnable default SSL configuration values.
 *                 (You need to call mbedtls_ssl_config_init() first.)
 *
 * \param conf     SSL configuration context
 * \param endpoint MBEDTLS_SSL_IS_CLIENT or MBEDTLS_SSL_IS_SERVER
 * \param transport MBEDTLS_SSL_TRANSPORT_STREAM for TLS, or
 *                  MBEDTLS_SSL_TRANSPORT_DATAGRAM for DTLS
 * \param preset   a MBEDTLS_SSL_PRESET_XXX value
 *
 * \note           See \c mbedtls_ssl_conf_transport() for notes on DTLS.
 *
 * \return         0 if successful, or
 *                 MBEDTLS_ERR_XXX_ALLOC_FAILED on memory allocation error.
 */

Func mbedtls_ssl_config_free

void mbedtls_ssl_config_free( mbedtls_ssl_config *conf );
/**
 * \brief          Free an SSL configuration context
 *
 * \param conf     SSL configuration context
 */

Func mbedtls_ssl_session_init

void mbedtls_ssl_session_init( mbedtls_ssl_session *session );
/**
 * \brief          Initialize SSL session structure
 *
 * \param session  SSL session
 */

Func mbedtls_ssl_session_free

void mbedtls_ssl_session_free( mbedtls_ssl_session *session );
/**
 * \brief          Free referenced items in an SSL session including the
 *                 peer certificate and clear memory
 *
 * \note           A session object can be freed even if the SSL context
 *                 that was used to retrieve the session is still in use.
 *
 * \param session  SSL session
 */

Func mbedtls_ssl_session_free_peer_cert

void mbedtls_ssl_session_free_peer_cert( mbedtls_ssl_session *session );

      

Vars

Variable MBEDTLS_DEPRECATED

MBEDTLS_DEPRECATED int mbedtls_ssl_conf_dh_param( mbedtls_ssl_config *conf,
                                                 const char *dhm_P,
                                                 const char *dhm_G );
/**
 * \brief          Set the Diffie-Hellman public P and G values,
 *                 read as hexadecimal strings (server-side only)
 *                 (Default values: MBEDTLS_DHM_RFC3526_MODP_2048_[PG])
 *
 * \param conf     SSL configuration
 * \param dhm_P    Diffie-Hellman-Merkle modulus
 * \param dhm_G    Diffie-Hellman-Merkle generator
 *
 * \deprecated     Superseded by \c mbedtls_ssl_conf_dh_param_bin.
 *
 * \return         0 if successful
 */

Variable mbedtls_ssl_srtp_profile

mbedtls_ssl_srtp_profile mbedtls_ssl_get_dtls_srtp_protection_profile( const mbedtls_ssl_context *ssl );
/**
 * \brief          Get the negotiated DTLS-SRTP Protection Profile.
 *                 This function should be called after the handshake is
 *                 completed.
 *
 * \param ssl      SSL context
 *
 * \return         Protection Profile enum member,
 *                 MBEDTLS_SRTP_UNSET_PROFILE if no protocol was negotiated.
 */

Consts

Const

const unsigned char *key_enc, const unsigned char *key_dec,
               size_t keylen,
               const unsigned char *iv_enc, const unsigned char *iv_dec,
               size_t ivlen,
               const unsigned char *mac_enc, const unsigned char *mac_dec,
               size_t maclen);


      

Const

const char *mbedtls_ssl_get_ciphersuite_name( const int ciphersuite_id );
/**
 * \brief               Return the name of the ciphersuite associated with the
 *                      given ID
 *
 * \param ciphersuite_id SSL ciphersuite ID
 *
 * \return              a string containing the ciphersuite name
 */

Const

const char *mbedtls_ssl_get_alpn_protocol( const mbedtls_ssl_context *ssl );
/**
 * \brief          Get the name of the negotiated Application Layer Protocol.
 *                 This function should be called after the handshake is
 *                 completed.
 *
 * \param ssl      SSL context
 *
 * \return         Protcol name, or NULL if no protocol was negotiated.
 */

Const

const mbedtls_ssl_srtp_profile_info *mbedtls_ssl_dtls_srtp_profile_info_from_id( mbedtls_ssl_srtp_profile profile );
/**
 * \brief                  Utility function to get information on dtls srtp profile.
 *
 * \param profile          The dtls-srtp profile id to get info on.
 *
 * \return         mbedtls_ssl_srtp_profile_info* on success, NULL if not found
 */

Const

const char *mbedtls_ssl_get_ciphersuite( const mbedtls_ssl_context *ssl );
/**
 * \brief          Return the name of the current ciphersuite
 *
 * \param ssl      SSL context
 *
 * \return         a string containing the ciphersuite name
 */

Const

const char *mbedtls_ssl_get_version( const mbedtls_ssl_context *ssl );
/**
 * \brief          Return the current SSL version (SSLv3/TLSv1/etc)
 *
 * \param ssl      SSL context
 *
 * \return         a string containing the SSL version
 */

Const

const mbedtls_x509_crt *mbedtls_ssl_get_peer_cert( const mbedtls_ssl_context *ssl );
/**
 * \brief          Return the peer certificate from the current connection
 *
 *                 Note: Can be NULL in case no certificate was sent during
 *                 the handshake. Different calls for the same connection can
 *                 return the same or different pointers for the same
 *                 certificate and even a different certificate altogether.
 *                 The peer cert CAN change in a single connection if
 *                 renegotiation is performed.
 *
 * \param ssl      SSL context
 *
 * \return         the current peer certificate
 */

Types

Typedefs

Typedef mbedtls_ssl_states;

typedef enum
{
   MBEDTLS_SSL_HELLO_REQUEST,
   MBEDTLS_SSL_CLIENT_HELLO,
   MBEDTLS_SSL_SERVER_HELLO,
   MBEDTLS_SSL_SERVER_CERTIFICATE,
   MBEDTLS_SSL_SERVER_KEY_EXCHANGE,
   MBEDTLS_SSL_CERTIFICATE_REQUEST,
   MBEDTLS_SSL_SERVER_HELLO_DONE,
   MBEDTLS_SSL_CLIENT_CERTIFICATE,
   MBEDTLS_SSL_CLIENT_KEY_EXCHANGE,
   MBEDTLS_SSL_CERTIFICATE_VERIFY,
   MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC,
   MBEDTLS_SSL_CLIENT_FINISHED,
   MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC,
   MBEDTLS_SSL_SERVER_FINISHED,
   MBEDTLS_SSL_FLUSH_BUFFERS,
   MBEDTLS_SSL_HANDSHAKE_WRAPUP,
   MBEDTLS_SSL_HANDSHAKE_OVER,
   MBEDTLS_SSL_SERVER_NEW_SESSION_TICKET,
   MBEDTLS_SSL_SERVER_HELLO_VERIFY_REQUEST_SENT,
}
mbedtls_ssl_states;
/*
 * SSL state machine
 */

Typedef mbedtls_ssl_send_t

typedef int mbedtls_ssl_send_t( void *ctx,
                               const unsigned char *buf,
                               size_t len );
/**
 * \brief          Callback type: send data on the network.
 *
 * \note           That callback may be either blocking or non-blocking.
 *
 * \param ctx      Context for the send callback (typically a file descriptor)
 * \param buf      Buffer holding the data to send
 * \param len      Length of the data to send
 *
 * \return         The callback must return the number of bytes sent if any,
 *                 or a non-zero error code.
 *                 If performing non-blocking I/O, \c MBEDTLS_ERR_SSL_WANT_WRITE
 *                 must be returned when the operation would block.
 *
 * \note           The callback is allowed to send fewer bytes than requested.
 *                 It must always return the number of bytes actually sent.
 */

Typedef mbedtls_ssl_recv_t

typedef int mbedtls_ssl_recv_t( void *ctx,
                               unsigned char *buf,
                               size_t len );
/**
 * \brief          Callback type: receive data from the network.
 *
 * \note           That callback may be either blocking or non-blocking.
 *
 * \param ctx      Context for the receive callback (typically a file
 *                 descriptor)
 * \param buf      Buffer to write the received data to
 * \param len      Length of the receive buffer
 *
 * \return         The callback must return the number of bytes received,
 *                 or a non-zero error code.
 *                 If performing non-blocking I/O, \c MBEDTLS_ERR_SSL_WANT_READ
 *                 must be returned when the operation would block.
 *
 * \note           The callback may receive fewer bytes than the length of the
 *                 buffer. It must always return the number of bytes actually
 *                 received and written to the buffer.
 */

Typedef mbedtls_ssl_recv_timeout_t

typedef int mbedtls_ssl_recv_timeout_t( void *ctx,
                                       unsigned char *buf,
                                       size_t len,
                                       uint32_t timeout );
/**
 * \brief          Callback type: receive data from the network, with timeout
 *
 * \note           That callback must block until data is received, or the
 *                 timeout delay expires, or the operation is interrupted by a
 *                 signal.
 *
 * \param ctx      Context for the receive callback (typically a file descriptor)
 * \param buf      Buffer to write the received data to
 * \param len      Length of the receive buffer
 * \param timeout  Maximum nomber of millisecondes to wait for data
 *                 0 means no timeout (potentially waiting forever)
 *
 * \return         The callback must return the number of bytes received,
 *                 or a non-zero error code:
 *                 \c MBEDTLS_ERR_SSL_TIMEOUT if the operation timed out,
 *                 \c MBEDTLS_ERR_SSL_WANT_READ if interrupted by a signal.
 *
 * \note           The callback may receive fewer bytes than the length of the
 *                 buffer. It must always return the number of bytes actually
 *                 received and written to the buffer.
 */

Typedef mbedtls_ssl_set_timer_t

typedef void mbedtls_ssl_set_timer_t( void * ctx,
                                     uint32_t int_ms,
                                     uint32_t fin_ms );
/**
 * \brief          Callback type: set a pair of timers/delays to watch
 *
 * \param ctx      Context pointer
 * \param int_ms   Intermediate delay in milliseconds
 * \param fin_ms   Final delay in milliseconds
 *                 0 cancels the current timer.
 *
 * \note           This callback must at least store the necessary information
 *                 for the associated \c mbedtls_ssl_get_timer_t callback to
 *                 return correct information.
 *
 * \note           If using a event-driven style of programming, an event must
 *                 be generated when the final delay is passed. The event must
 *                 cause a call to \c mbedtls_ssl_handshake() with the proper
 *                 SSL context to be scheduled. Care must be taken to ensure
 *                 that at most one such call happens at a time.
 *
 * \note           Only one timer at a time must be running. Calling this
 *                 function while a timer is running must cancel it. Cancelled
 *                 timers must not generate any event.
 */

Typedef mbedtls_ssl_get_timer_t

typedef int mbedtls_ssl_get_timer_t( void * ctx );
/**
 * \brief          Callback type: get status of timers/delays
 *
 * \param ctx      Context pointer
 *
 * \return         This callback must return:
 *                 -1 if cancelled (fin_ms == 0),
 *                  0 if none of the delays have passed,
 *                  1 if only the intermediate delay has passed,
 *                  2 if the final delay has passed.
 */

Typedef mbedtls_ssl_session

typedef struct mbedtls_ssl_session mbedtls_ssl_session;
/* Defined below */

Typedef mbedtls_ssl_context

typedef struct mbedtls_ssl_context mbedtls_ssl_context;


      

Typedef mbedtls_ssl_config

typedef struct mbedtls_ssl_config mbedtls_ssl_config;


      

Typedef mbedtls_ssl_transform

typedef struct mbedtls_ssl_transform mbedtls_ssl_transform;
/* Defined in ssl_internal.h */

Typedef mbedtls_ssl_handshake_params

typedef struct mbedtls_ssl_handshake_params mbedtls_ssl_handshake_params;


      

Typedef mbedtls_ssl_sig_hash_set_t

typedef struct mbedtls_ssl_sig_hash_set_t mbedtls_ssl_sig_hash_set_t;
#if defined(MBEDTLS_X509_CRT_PARSE_C)
typedef struct mbedtls_ssl_key_cert mbedtls_ssl_key_cert;


      

Typedef mbedtls_ssl_flight_item

typedef struct mbedtls_ssl_flight_item mbedtls_ssl_flight_item;


      

Typedef mbedtls_ssl_async_sign_t

typedef int mbedtls_ssl_async_sign_t( mbedtls_ssl_context *ssl,
                                     mbedtls_x509_crt *cert,
                                     mbedtls_md_type_t md_alg,
                                     const unsigned char *hash,
                                     size_t hash_len );
/**
 * \brief           Callback type: start fal signature operation.
 *
 *                  This callback is called during an SSL handshake to start
 *                  a signature decryption operation using an
 *                  external processor. The parameter \p cert contains
 *                  the public key; it is up to the callback function to
 *                  determine how to access the associated private key.
 *
 *                  This function typically sends or enqueues a request, and
 *                  does not wait for the operation to complete. This allows
 *                  the handshake step to be non-blocking.
 *
 *                  The parameters \p ssl and \p cert are guaranteed to remain
 *                  valid throughout the handshake. On the other hand, this
 *                  function must save the contents of \p hash if the value
 *                  is needed for later processing, because the \p hash buffer
 *                  is no longer valid after this function returns.
 *
 *                  This function may call mbedtls_ssl_set_async_operation_data()
 *                  to store an operation context for later retrieval
 *                  by the resume or cancel callback.
 *
 * \note            For RSA signatures, this function must produce output
 *                  that is consistent with PKCS#1 v1.5 in the same way as
 *                  mbedtls_rsa_pkcs1_sign(). Before the private key operation,
 *                  apply the padding steps described in RFC 8017, section 9.2
 *                  "EMSA-PKCS1-v1_5" as follows.
 *                  - If \p md_alg is #MBEDTLS_MD_NONE, apply the PKCS#1 v1.5
 *                    encoding, treating \p hash as the DigestInfo to be
 *                    padded. In other words, apply EMSA-PKCS1-v1_5 starting
 *                    from step 3, with `T = hash` and `tLen = hash_len`.
 *                  - If `md_alg != MBEDTLS_MD_NONE`, apply the PKCS#1 v1.5
 *                    encoding, treating \p hash as the hash to be encoded and
 *                    padded. In other words, apply EMSA-PKCS1-v1_5 starting
 *                    from step 2, with `digestAlgorithm` obtained by calling
 *                    mbedtls_oid_get_oid_by_md() on \p md_alg.
 *
 * \note            For ECDSA signatures, the output format is the DER encoding
 *                  `Ecdsa-Sig-Value` defined in
 *                  [RFC 4492 section 5.4](https://tools.ietf.org/html/rfc4492#section-5.4).
 *
 * \param ssl             The SSL connection instance. It should not be
 *                        modified other than via
 *                        mbedtls_ssl_set_async_operation_data().
 * \param cert            Certificate containing the public key.
 *                        In simple cases, this is one of the pointers passed to
 *                        mbedtls_ssl_conf_own_cert() when configuring the SSL
 *                        connection. However, if other callbacks are used, this
 *                        property may not hold. For example, if an SNI callback
 *                        is registered with mbedtls_ssl_conf_sni(), then
 *                        this callback determines what certificate is used.
 * \param md_alg          Hash algorithm.
 * \param hash            Buffer containing the hash. This buffer is
 *                        no longer valid when the function returns.
 * \param hash_len        Size of the \c hash buffer in bytes.
 *
 * \return          0 if the operation was started successfully and the SSL
 *                  stack should call the resume callback immediately.
 * \return          #MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS if the operation
 *                  was started successfully and the SSL stack should return
 *                  immediately without calling the resume callback yet.
 * \return          #MBEDTLS_ERR_SSL_HW_ACCEL_FALLTHROUGH if the external
 *                  processor does not support this key. The SSL stack will
 *                  use the private key object instead.
 * \return          Any other error indicates a fatal failure and is
 *                  propagated up the call chain. The callback should
 *                  use \c MBEDTLS_ERR_PK_xxx error codes, and must not
 *                  use \c MBEDTLS_ERR_SSL_xxx error codes except as
 *                  directed in the documentation of this callback.
 */

Typedef mbedtls_ssl_async_decrypt_t

typedef int mbedtls_ssl_async_decrypt_t( mbedtls_ssl_context *ssl,
                                        mbedtls_x509_crt *cert,
                                        const unsigned char *input,
                                        size_t input_len );
/**
 * \brief           Callback type: start external decryption operation.
 *
 *                  This callback is called during an SSL handshake to start
 *                  an RSA decryption operation using an
 *                  external processor. The parameter \p cert contains
 *                  the public key; it is up to the callback function to
 *                  determine how to access the associated private key.
 *
 *                  This function typically sends or enqueues a request, and
 *                  does not wait for the operation to complete. This allows
 *                  the handshake step to be non-blocking.
 *
 *                  The parameters \p ssl and \p cert are guaranteed to remain
 *                  valid throughout the handshake. On the other hand, this
 *                  function must save the contents of \p input if the value
 *                  is needed for later processing, because the \p input buffer
 *                  is no longer valid after this function returns.
 *
 *                  This function may call mbedtls_ssl_set_async_operation_data()
 *                  to store an operation context for later retrieval
 *                  by the resume or cancel callback.
 *
 * \warning         RSA decryption as used in TLS is subject to a potential
 *                  timing side channel attack first discovered by Bleichenbacher
 *                  in 1998. This attack can be remotely exploitable
 *                  in practice. To avoid this attack, you must ensure that
 *                  if the callback performs an RSA decryption, the time it
 *                  takes to execute and return the result does not depend
 *                  on whether the RSA decryption succeeded or reported
 *                  invalid padding.
 *
 * \param ssl             The SSL connection instance. It should not be
 *                        modified other than via
 *                        mbedtls_ssl_set_async_operation_data().
 * \param cert            Certificate containing the public key.
 *                        In simple cases, this is one of the pointers passed to
 *                        mbedtls_ssl_conf_own_cert() when configuring the SSL
 *                        connection. However, if other callbacks are used, this
 *                        property may not hold. For example, if an SNI callback
 *                        is registered with mbedtls_ssl_conf_sni(), then
 *                        this callback determines what certificate is used.
 * \param input           Buffer containing the input ciphertext. This buffer
 *                        is no longer valid when the function returns.
 * \param input_len       Size of the \p input buffer in bytes.
 *
 * \return          0 if the operation was started successfully and the SSL
 *                  stack should call the resume callback immediately.
 * \return          #MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS if the operation
 *                  was started successfully and the SSL stack should return
 *                  immediately without calling the resume callback yet.
 * \return          #MBEDTLS_ERR_SSL_HW_ACCEL_FALLTHROUGH if the external
 *                  processor does not support this key. The SSL stack will
 *                  use the private key object instead.
 * \return          Any other error indicates a fatal failure and is
 *                  propagated up the call chain. The callback should
 *                  use \c MBEDTLS_ERR_PK_xxx error codes, and must not
 *                  use \c MBEDTLS_ERR_SSL_xxx error codes except as
 *                  directed in the documentation of this callback.
 */

Typedef mbedtls_ssl_async_resume_t

typedef int mbedtls_ssl_async_resume_t( mbedtls_ssl_context *ssl,
                                       unsigned char *output,
                                       size_t *output_len,
                                       size_t output_size );
/**
 * \brief           Callback type: resume external operation.
 *
 *                  This callback is called during an SSL handshake to resume
 *                  an external operation started by the
 *                  ::mbedtls_ssl_async_sign_t or
 *                  ::mbedtls_ssl_async_decrypt_t callback.
 *
 *                  This function typically checks the status of a pending
 *                  request or causes the request queue to make progress, and
 *                  does not wait for the operation to complete. This allows
 *                  the handshake step to be non-blocking.
 *
 *                  This function may call mbedtls_ssl_get_async_operation_data()
 *                  to retrieve an operation context set by the start callback.
 *                  It may call mbedtls_ssl_set_async_operation_data() to modify
 *                  this context.
 *
 *                  Note that when this function returns a status other than
 *                  #MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS, it must free any
 *                  resources associated with the operation.
 *
 * \param ssl             The SSL connection instance. It should not be
 *                        modified other than via
 *                        mbedtls_ssl_set_async_operation_data().
 * \param output          Buffer containing the output (signature or decrypted
 *                        data) on success.
 * \param output_len      On success, number of bytes written to \p output.
 * \param output_size     Size of the \p output buffer in bytes.
 *
 * \return          0 if output of the operation is available in the
 *                  \p output buffer.
 * \return          #MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS if the operation
 *                  is still in progress. Subsequent requests for progress
 *                  on the SSL connection will call the resume callback
 *                  again.
 * \return          Any other error means that the operation is aborted.
 *                  The SSL handshake is aborted. The callback should
 *                  use \c MBEDTLS_ERR_PK_xxx error codes, and must not
 *                  use \c MBEDTLS_ERR_SSL_xxx error codes except as
 *                  directed in the documentation of this callback.
 */

Typedef mbedtls_ssl_async_cancel_t

typedef void mbedtls_ssl_async_cancel_t( mbedtls_ssl_context *ssl );
/**
 * \brief           Callback type: cancel external operation.
 *
 *                  This callback is called if an SSL connection is closed
 *                  while an asynchronous operation is in progress. Note that
 *                  this callback is not called if the
 *                  ::mbedtls_ssl_async_resume_t callback has run and has
 *                  returned a value other than
 *                  #MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS, since in that case
 *                  the asynchronous operation has already completed.
 *
 *                  This function may call mbedtls_ssl_get_async_operation_data()
 *                  to retrieve an operation context set by the start callback.
 *
 * \param ssl             The SSL connection instance. It should not be
 *                        modified.
 */

Typedef mbedtls_ssl_srtp_profile;

typedef enum
{
   MBEDTLS_SRTP_UNSET_PROFILE,
   MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_80,
   MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_32,
   MBEDTLS_SRTP_NULL_HMAC_SHA1_80,
   MBEDTLS_SRTP_NULL_HMAC_SHA1_32,
}
mbedtls_ssl_srtp_profile;
/*
 * List of SRTP profiles for DTLS-SRTP
 */

Typedef mbedtls_ssl_srtp_profile_info;

typedef struct
{
   const mbedtls_ssl_srtp_profile  profile;
   const char                     *name;
}
mbedtls_ssl_srtp_profile_info;


      

Typedef mbedtls_dtls_srtp_info;

typedef struct mbedtls_dtls_srtp_info_t
{
   mbedtls_ssl_srtp_profile chosen_dtls_srtp_profile; /*!< negotiated SRTP profile */
   unsigned char dtls_srtp_keys[MBEDTLS_DTLS_SRTP_MAX_KEY_MATERIAL_LENGTH]; /*!< master keys and master salt for SRTP generated during handshake */
   size_t dtls_srtp_keys_len; /*!< length in bytes of master keys and master salt for SRTP generated during handshake */
   unsigned char mki_value[MBEDTLS_DTLS_SRTP_MAX_MKI_LENGTH]; /* opaque srtp_mki<0..255> */
   size_t                mki_len;
}
mbedtls_dtls_srtp_info;


      

Typedef psk_func_cb

typedef void (*psk_func_cb)(void *ctx);


      

Typedef mbedtls_ssl_ticket_write_t

typedef int mbedtls_ssl_ticket_write_t( void *p_ticket,
                                       const mbedtls_ssl_session *session,
                                       unsigned char *start,
                                       const unsigned char *end,
                                       size_t *tlen,
                                       uint32_t *lifetime );
/**
 * \brief           Callback type: generate and write session ticket
 *
 * \note            This describes what a callback implementation should do.
 *                  This callback should generate an encrypted and
 *                  authenticated ticket for the session and write it to the
 *                  output buffer. Here, ticket means the opaque ticket part
 *                  of the NewSessionTicket structure of RFC 5077.
 *
 * \param p_ticket  Context for the callback
 * \param session   SSL session to be written in the ticket
 * \param start     Start of the output buffer
 * \param end       End of the output buffer
 * \param tlen      On exit, holds the length written
 * \param lifetime  On exit, holds the lifetime of the ticket in seconds
 *
 * \return          0 if successful, or
 *                  a specific MBEDTLS_ERR_XXX code.
 */

Typedef mbedtls_ssl_export_keys_t

typedef int mbedtls_ssl_export_keys_t( void *p_expkey,
                               const unsigned char *ms,
                               const unsigned char *kb,
                               size_t maclen,
                               size_t keylen,
                               size_t ivlen );
/**
 * \brief           Callback type: Export key block and master secret
 *
 * \note            This is required for certain uses of TLS, e.g. EAP-TLS
 *                  (RFC 5216) and Thread. The key pointers are ephemeral and
 *                  therefore must not be stored. The master secret and keys
 *                  should not be used directly except as an input to a key
 *                  derivation function.
 *
 * \param p_expkey  Context for the callback
 * \param ms        Pointer to master secret (fixed length: 48 bytes)
 * \param kb        Pointer to key block, see RFC 5246 section 6.3
 *                  (variable length: 2 * maclen + 2 * keylen + 2 * ivlen).
 * \param maclen    MAC length
 * \param keylen    Key length
 * \param ivlen     IV length
 *
 * \return          0 if successful, or
 *                  a specific MBEDTLS_ERR_XXX code.
 */

Typedef mbedtls_ssl_ticket_parse_t

typedef int mbedtls_ssl_ticket_parse_t( void *p_ticket,
                                       mbedtls_ssl_session *session,
                                       unsigned char *buf,
                                       size_t len );
/**
 * \brief           Callback type: parse and load session ticket
 *
 * \note            This describes what a callback implementation should do.
 *                  This callback should parse a session ticket as generated
 *                  by the corresponding mbedtls_ssl_ticket_write_t function,
 *                  and, if the ticket is authentic and valid, load the
 *                  session.
 *
 * \note            The implementation is allowed to modify the first len
 *                  bytes of the input buffer, eg to use it as a temporary
 *                  area for the decrypted ticket contents.
 *
 * \param p_ticket  Context for the callback
 * \param session   SSL session to be loaded
 * \param buf       Start of the buffer containing the ticket
 * \param len       Length of the ticket.
 *
 * \return          0 if successful, or
 *                  MBEDTLS_ERR_SSL_INVALID_MAC if not authentic, or
 *                  MBEDTLS_ERR_SSL_SESSION_TICKET_EXPIRED if expired, or
 *                  any other non-zero code for other failures.
 */
typedef int mbedtls_ssl_cookie_write_t( void *ctx,
                               unsigned char **p, unsigned char *end,
                               const unsigned char *info, size_t ilen );
/**
 * \brief          Callback type: generate a cookie
 *
 * \param ctx      Context for the callback
 * \param p        Buffer to write to,
 *                 must be updated to point right after the cookie
 * \param end      Pointer to one past the end of the output buffer
 * \param info     Client ID info that was passed to
 *                 \c mbedtls_ssl_set_client_transport_id()
 * \param ilen     Length of info in bytes
 *
 * \return         The callback must return 0 on success,
 *                 or a negative error code.
 */
typedef int mbedtls_ssl_cookie_check_t( void *ctx,
                               const unsigned char *cookie, size_t clen,
                               const unsigned char *info, size_t ilen );
/**
 * \brief          Callback type: verify a cookie
 *
 * \param ctx      Context for the callback
 * \param cookie   Cookie to verify
 * \param clen     Length of cookie
 * \param info     Client ID info that was passed to
 *                 \c mbedtls_ssl_set_client_transport_id()
 * \param ilen     Length of info in bytes
 *
 * \return         The callback must return 0 if cookie is valid,
 *                 or a negative error code.
 */