SSL_accept(3)               OpenSSL               SSL_accept(3)





NAME
       SSL_accept - wait for a TLS/SSL client to initiate a
       TLS/SSL handshake

SYNOPSIS
        #include <openssl/ssl.h>

        int SSL_accept(SSL *ssl);

DESCRIPTION
       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.

NOTES
       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 Cryptogra-
       phy). 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 sat-
       isfy 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.

RETURN VALUES
       The following return values can occur:

       1   The TLS/SSL handshake was successfully completed, a
           TLS/SSL connection has been established.

       o   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.

       <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 con-
           tinue the operation for non-blocking BIOs. Call
           SSL_get_error() with the return value ret to find
           out the reason.

SEE ALSO
       SSL_get_error(3), SSL_connect(3), SSL_shutdown(3),
       ssl(3), bio(3), SSL_set_connect_state(3), SSL_do_hand-
       shake(3), SSL_CTX_new(3)



