diff options
Diffstat (limited to 'crypto/openssl/doc/ssl/SSL_get_error.pod')
| -rw-r--r-- | crypto/openssl/doc/ssl/SSL_get_error.pod | 30 |
1 files changed, 20 insertions, 10 deletions
diff --git a/crypto/openssl/doc/ssl/SSL_get_error.pod b/crypto/openssl/doc/ssl/SSL_get_error.pod index d85b564..fefaf61 100644 --- a/crypto/openssl/doc/ssl/SSL_get_error.pod +++ b/crypto/openssl/doc/ssl/SSL_get_error.pod @@ -14,8 +14,8 @@ SSL_get_error - obtain result code for TLS/SSL I/O operation 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 -TLS/SSL I/O function must be passed to SSL_get_error() in parameter +SSL_read(), SSL_peek(), or SSL_write() on B<ssl>. The value returned by +that TLS/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 @@ -48,16 +48,26 @@ has been closed. =item 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. 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 TLS/SSL I/O function should be retried. +called again later. 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>), 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 B<SSL_ERROR_WANT_READ> or B<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. + +For socket B<BIO>s (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 -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. +B<SSL_ERROR_WANT_READ> and B<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. =item SSL_ERROR_WANT_X509_LOOKUP |
