=pod =head1 NAME SSL_get_error - obtain result code for SSL I/O operation =head1 SYNOPSIS #include <openssl/ssl.h> int SSL_get_error(SSL *ssl, int ret); =head1 DESCRIPTION SSL_get_error() returns a result code (suitable for the C "switch" statement) for a preceding call to SSL_connect(), SSL_accept(), SSL_read(), or SSL_write() on B<ssl>. The value returned by that SSL I/O function must be passed to SSL_get_error() in parameter B<ret>. In addition to B<ssl> and B<ret>, SSL_get_error() inspects the current thread's OpenSSL error queue. Thus, SSL_get_error() must be used in the same thread that performed the SSL I/O operation, and no other OpenSSL function calls should appear in between. The current thread's error queue must be empty before the SSL I/O operation is attempted, or SSL_get_error() will not work reliably. =head1 RETURN VALUES The following return values can currently occur: =over 4 =item SSL_ERROR_NONE The SSL I/O operation completed. This result code is returned if and only if B<ret E<gt> 0>. =item SSL_ERROR_ZERO_RETURN The SSL connection has been closed. If the protocol version is SSL 3.0 or TLS 1.0, this result code is returned only if a closure alerts has occurred in the protocol, i.e. if the connection has been closed cleanly. =item SSL_ERROR_WANT_READ, SSL_ERROR_WANT_WRITE The operation did not complete; the same SSL I/O function should be called again later. There will be protocol progress if, by then, the underlying B<BIO> has data available for reading (if the result code is B<SSL_ERROR_WANT_READ>) or allows writing data (B<SSL_ERROR_WANT_WRITE>). For socket B<BIO>s (e.g. when SSL_set_fd() was used) this means that select() or poll() on the underlying socket can be used to find out when the SSL I/O function should be retried. Caveat: Any SSL I/O function can lead to either of B<SSL_ERROR_WANT_READ> and B<SSL_ERROR_WANT_WRITE>, i.e. SSL_read() may want to write data and SSL_write() may want to read data. =item SSL_ERROR_WANT_X509_LOOKUP The operation did not complete because an application callback set by SSL_CTX_set_client_cert_cb() has asked to be called again. The SSL I/O function should be called again later. Details depend on the application. =item SSL_ERROR_SYSCALL Some I/O error occurred. The OpenSSL error queue may contain more information on the error. If the error queue is empty (i.e. ERR_get_error() returns 0), B<ret> can be used to find out more about the error: If B<ret == 0>, an EOF was observed that violates the protocol. If B<ret == -1>, the underlying B<BIO> reported an I/O error (for socket I/O on Unix systems, consult B<errno> for details). =item SSL_ERROR_SSL A failure in the SSL library occurred, usually a protocol error. The OpenSSL error queue contains more information on the error. =back =head1 SEE ALSO L<ssl(3)|ssl(3)>, L<err(3)|err(3)> =head1 HISTORY SSL_get_error() was added in SSLeay 0.8. =cut