1SSL_connect(3)                      OpenSSL                     SSL_connect(3)
2
3
4

NAME

6       SSL_connect - initiate the TLS/SSL handshake with an TLS/SSL server
7

SYNOPSIS

9        #include <openssl/ssl.h>
10
11        int SSL_connect(SSL *ssl);
12

DESCRIPTION

14       SSL_connect() initiates the TLS/SSL handshake with a server. The
15       communication channel must already have been set and assigned to the
16       ssl by setting an underlying BIO.
17

NOTES

19       The behaviour of SSL_connect() depends on the underlying BIO.
20
21       If the underlying BIO is blocking, SSL_connect() will only return once
22       the handshake has been finished or an error occurred.
23
24       If the underlying BIO is non-blocking, SSL_connect() will also return
25       when the underlying BIO could not satisfy the needs of SSL_connect() to
26       continue the handshake, indicating the problem by the return value -1.
27       In this case a call to SSL_get_error() with the return value of
28       SSL_connect() will yield SSL_ERROR_WANT_READ or SSL_ERROR_WANT_WRITE.
29       The calling process then must repeat the call after taking appropriate
30       action to satisfy the needs of SSL_connect().  The action depends on
31       the underlying BIO. When using a non-blocking socket, nothing is to be
32       done, but select() can be used to check for the required condition.
33       When using a buffering BIO, like a BIO pair, data must be written into
34       or retrieved out of the BIO before being able to continue.
35

RETURN VALUES

37       The following return values can occur:
38
39       0   The TLS/SSL handshake was not successful but was shut down
40           controlled and by the specifications of the TLS/SSL protocol. Call
41           SSL_get_error() with the return value ret to find out the reason.
42
43       1   The TLS/SSL handshake was successfully completed, a TLS/SSL
44           connection has been established.
45
46       <0  The TLS/SSL handshake was not successful, because a fatal error
47           occurred either at the protocol level or a connection failure
48           occurred. The shutdown was not clean. It can also occur of action
49           is need to continue the operation for non-blocking BIOs. Call
50           SSL_get_error() with the return value ret to find out the reason.
51

SEE ALSO

53       SSL_get_error(3), SSL_accept(3), SSL_shutdown(3), ssl(3), bio(3),
54       SSL_set_connect_state(3), SSL_do_handshake(3), SSL_CTX_new(3)
55
56
57
581.0.2o                            2020-08-01                    SSL_connect(3)
Impressum