From 2984b0ae248f876823e8981d3b1bbf9f9bf2e3ff Mon Sep 17 00:00:00 2001 From: =?utf8?q?Bodo=20M=C3=B6ller?= Date: Sun, 12 Nov 2000 19:17:22 +0000 Subject: [PATCH] Additional explanations for SSL_ERROR_WANT_READ/WRITE. --- doc/ssl/SSL_get_error.pod | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-) diff --git a/doc/ssl/SSL_get_error.pod b/doc/ssl/SSL_get_error.pod index d85b564258..747b99741b 100644 --- a/doc/ssl/SSL_get_error.pod +++ b/doc/ssl/SSL_get_error.pod @@ -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 has data available for reading (if the result code is -B) or allows writing data (B). -For socket Bs (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 has data +available for reading (if the result code is B) +or allows writing data (B), 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 or B 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 Bs (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 and B, i.e. SSL_read() -may want to write data and SSL_write() may want to read data. +B and B. In particular, +SSL_read() may want to write data and SSL_write() may want to read +data. This is because TLS/SSL handshakes may occur at any time +during the protocol (initiated by either the client or the server); +SSL_read() and SSL_write() will handle any pending handshakes. =item SSL_ERROR_WANT_X509_LOOKUP -- 2.25.1