SSL_accept(3) OpenSSL SSL_accept(3)
SSL_accept - wait for a TLS/SSL client to initiate a TLS/SSL handshake
int SSL_accept(SSL *ssl);
SSL_accept() waits for a TLS/SSL client to initiate the TLS/SSL handshake. The communication channel must already have been set and
assigned to the ssl by setting an underlying BIO.
The behaviour of SSL_accept() depends on the underlying BIO.
If the underlying BIO is blocking, SSL_accept() will only return once the handshake has been finished or an error occurred, except for SGC
(Server Gated Cryptography). For SGC, SSL_accept() may return with -1, but SSL_get_error() will yield SSL_ERROR_WANT_READ/WRITE and
SSL_accept() should be called again.
If the underlying BIO is non-blocking, SSL_accept() will also return when the underlying BIO could not satisfy the needs of SSL_accept() 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_accept() will yield SSL_ERROR_WANT_READ or SSL_ERROR_WANT_WRITE. The calling process then must repeat the call after taking appropriate
action to satisfy the needs of SSL_accept(). 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.
The following return values can occur:
1. The TLS/SSL handshake was successfully completed, a TLS/SSL connection has been established.
2. 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 ret to find out the reason.
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 operation for non-blocking BIOs. Call SSL_get_error()
with the return value ret to find out the reason.
SSL_get_error(3), SSL_connect(3), SSL_shutdown(3), ssl(3), bio(3), SSL_set_connect_state(3), SSL_do_handshake(3), SSL_CTX_new(3)
Hey! The above document had some coding errors, which are explained below:
Around line 52:
You have '=item 0' instead of the expected '=item 2'
Around line 58:
Expected '=item 3'
50 2013-03-05 SSL_accept(3)