SSL_get_error(3)

     SSL_get_error(3)       0.9.6h (2002-07-29)       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 closure 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 necessary
              until progress becomes visible at application protocol
              level.

     Page 1                                         (printed 1/19/103)

     SSL_get_error(3)       0.9.6h (2002-07-29)       SSL_get_error(3)

              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 platforms 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 protocol.  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.

     Page 2                                         (printed 1/19/103)