OpenSSL SSL_connect(3openssl)
NNNNAAAAMMMMEEEESSL_connect - initiate the TLS/SSL handshake with an TLS/SSL
server SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS#include
int SSL_connect(SSL *ssl);
DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNNSSL_connect() initiates the TLS/SSL handshake with a server.
The communication channel must already have been set and assigned to the ssssssssllll by setting an underlying BBBBIIIIOOOO. NNNNOOOOTTTTEEEESSSSThe behaviour of SSL_connect() depends on the underlying
BIO.If the underlying BIO is bbbblllloooocccckkkkiiiinnnngggg, SSL_connect() will only
return once the handshake has been finished or an error occurred.If the underlying BIO is nnnnoooonnnn---bbblllloooocccckkkkiiiinnnngggg, SSL_connect() will
also return when the underlying BIO could not satisfy theneeds of SSL_connect() to continue the handshake, indicating
the problem by the return value -1. In this case a call to
SSL_get_error() with the return value of SSL_connect() will
yield SSSSSSSSLLLL_EEEERRRRRRRROOOORRRR_WWWWAAAANNNNTTTT_RRRREEEEAAAADDDD or SSSSSSSSLLLL_EEEERRRRRRRROOOORRRR_WWWWAAAANNNNTTTT_WWWWRRRRIIIITTTTEEEE. The
calling process then must repeat the call after takingappropriate action to satisfy the needs of SSL_connect().
The action depends on the underlying BIO. When using a non-
blocking socket, nothing is to be done, but select() can be used to check for the required condition. When using a buffering BIO, like a BIO pair, data must be written into or retrieved out of the BIO before being able to continue. RRRREEEETTTTUUUURRRRNNNN VVVVAAAALLLLUUUUEEEESSSS The following return values can occur:1 The TLS/SSL handshake was successfully completed, a
TLS/SSL connection has been established.
0 The TLS/SSL handshake was not successful but was shut
down controlled and by the specifications of the TLS/SSL
protocol. Call SSL_get_error() with the return value rrrreeeetttt
to find out the reason.<0 The TLS/SSL handshake was not successful, because a fatal error occurred either at the protocol level or a connection failure occurred. The shutdown was not clean. It can also occur of action is need to continue the
3/Jun/2003 Last change: 0.9.8o 1
OpenSSL SSL_connect(3openssl)
operation for non-blocking BIOs. Call SSL_get_error()
with the return value rrrreeeetttt to find out the reason. SSSSEEEEEEEE AAAALLLLSSSSOOOOSSL_get_error(3), SSL_accept(3), SSL_shutdown(3), ssl(3),
bio(3), SSL_set_connect_state(3), SSL_do_handshake(3),
SSL_CTX_new(3)
3/Jun/2003 Last change: 0.9.8o 2