SSL_get_error

SSL_get_error(3)		   OpenSSL		     SSL_get_error(3)



NAME
       SSL_get_error - obtain result code for TLS/SSL I/O operation

SYNOPSIS
	#include <openssl/ssl.h>

	int SSL_get_error(SSL *ssl, int ret);

DESCRIPTION
       SSL_get_error() returns a result code (suitable for the C "switch"
       statement) for a preceding call to SSL_connect(), SSL_accept(),
       SSL_do_handshake(), SSL_read(), SSL_peek(), or SSL_write() on ssl.
       The value returned by that TLS/SSL I/O function must be passed to
       SSL_get_error() in parameter ret.

       In addition to ssl and 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 TLS/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 TLS/SSL I/O operation is
       attempted, or SSL_get_error() will not work reliably.

RETURN VALUES
       The following return values can currently occur:

       SSL_ERROR_NONE
	   The TLS/SSL I/O operation completed.	 This result code is returned
	   if and only if ret > 0.

       SSL_ERROR_ZERO_RETURN
	   The TLS/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 clo-
	   sure alert has occurred in the protocol, i.e. if the connection
	   has been closed cleanly. Note that in this case
	   SSL_ERROR_ZERO_RETURN does not necessarily indicate that the
	   underlying transport has been closed.

       SSL_ERROR_WANT_READ, SSL_ERROR_WANT_WRITE
	   The operation did not complete; the same TLS/SSL I/O function
	   should be called again later.  If, by then, the underlying BIO has
	   data available for reading (if the result code is
	   SSL_ERROR_WANT_READ) or allows writing data
	   (SSL_ERROR_WANT_WRITE), then some TLS/SSL protocol progress will
	   take place, i.e. at least part of an TLS/SSL record will be read
	   or written.	Note that the retry may again lead to a
	   SSL_ERROR_WANT_READ or SSL_ERROR_WANT_WRITE condition.  There is
	   no fixed upper limit for the number of iterations that may be nec-
	   essary until progress becomes visible at application protocol
	   level.

	   For socket BIOs (e.g. when SSL_set_fd() was used), select() or
	   poll() on the underlying socket can be used to find out when the
	   TLS/SSL I/O function should be retried.

	   Caveat: Any TLS/SSL I/O function can lead to either of
	   SSL_ERROR_WANT_READ and SSL_ERROR_WANT_WRITE.  In particular,
	   SSL_read() or SSL_peek() may want to write data and SSL_write()
	   may want to read data.  This is mainly because TLS/SSL handshakes
	   may occur at any time during the protocol (initiated by either the
	   client or the server); SSL_read(), SSL_peek(), and SSL_write()
	   will handle any pending handshakes.

       SSL_ERROR_WANT_CONNECT, SSL_ERROR_WANT_ACCEPT
	   The operation did not complete; the same TLS/SSL I/O function
	   should be called again later. The underlying BIO was not connected
	   yet to the peer and the call would block in connect()/accept().
	   The SSL function should be called again when the connection is
	   established. These messages can only appear with a BIO_s_connect()
	   or BIO_s_accept() BIO, respectively.	 In order to find out, when
	   the connection has been successfully established, on many plat-
	   forms select() or poll() for writing on the socket file descriptor
	   can be used.

       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
	   TLS/SSL I/O function should be called again later.  Details depend
	   on the application.

       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), ret can be used to find out more about
	   the error: If ret == 0, an EOF was observed that violates the pro-
	   tocol.  If ret == -1, the underlying BIO reported an I/O error
	   (for socket I/O on Unix systems, consult errno for details).

       SSL_ERROR_SSL
	   A failure in the SSL library occurred, usually a protocol error.
	   The OpenSSL error queue contains more information on the error.

SEE ALSO
       ssl(3), err(3)

HISTORY
       SSL_get_error() was added in SSLeay 0.8.



0.9.7a				  2002-07-29		     SSL_get_error(3)