/usr/man/cat.3/SSL_CTX_set_psk_client_callback.3

SSL_CTX_set_psk_client_callback(3OpenSSSSL_CTX_set_psk_client_callback(3)

NAME

     SSL_CTX_set_psk_client_callback, SSL_set_psk_client_callback
     - set PSK client callback

SYNOPSIS

      #include <openssl/ssl.h>

      void SSL_CTX_set_psk_client_callback(SSL_CTX *ctx,
             unsigned int (*callback)(SSL *ssl, const char *hint,
             char *identity, unsigned int max_identity_len,
             unsigned char *psk, unsigned int max_psk_len));
      void SSL_set_psk_client_callback(SSL *ssl,
             unsigned int (*callback)(SSL *ssl, const char *hint,
             char *identity, unsigned int max_identity_len,
             unsigned char *psk, unsigned int max_psk_len));

DESCRIPTION

     A client application must provide a callback function which
     is called when the client is sending the ClientKeyExchange
     message to the server.

     The purpose of the callback function is to select the PSK
     identity and the pre-shared key to use during the connection
     setup phase.

     The callback is set using functions
     SSL_CTX_set_psk_client_callback() or
     SSL_set_psk_client_callback(). The callback function is
     given the connection in parameter ssl, a NULL-terminated PSK
     identity hint sent by the server in parameter hint, a buffer
     identity of length max_identity_len bytes where the the
     resulting NULL-terminated identity is to be stored, and a
     buffer psk of length max_psk_len bytes where the resulting
     pre-shared key is to be stored.

NOTES

     Note that parameter hint given to the callback may be NULL.

RETURN VALUES

     Return values from the client callback are interpreted as
     follows:

     On success (callback found a PSK identity and a pre-shared
     key to use) the length (> 0) of psk in bytes is returned.

     Otherwise or on errors callback should return 0. In this
     case the connection setup fails.

1.0.2t               Last change: 2019-09-10                    1

See also SSL_set_psk_client_callback(3)