From 971a7c5ff751d95bf33117e95a6acf2cfc951537 Mon Sep 17 00:00:00 2001 From: Matt Caswell Date: Sun, 11 May 2014 11:27:26 +0100 Subject: [PATCH] Move length check earlier to ensure we don't go beyond the end of the user's buffer. PR#3320 --- ssl/s3_pkt.c | 29 +++++++++++++++-------------- 1 file changed, 15 insertions(+), 14 deletions(-) diff --git a/ssl/s3_pkt.c b/ssl/s3_pkt.c index 41193bb7d1..ad9dc5154a 100644 --- a/ssl/s3_pkt.c +++ b/ssl/s3_pkt.c @@ -658,6 +658,21 @@ int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len) } } + /* ensure that if we end up with a smaller value of data to write + * out than the the original len from a write which didn't complete + * for non-blocking I/O and also somehow ended up avoiding + * the check for this in ssl3_write_pending/SSL_R_BAD_WRITE_RETRY as + * it must never be possible to end up with (len-tot) as a large + * number that will then promptly send beyond the end of the users + * buffer ... so we trap and report the error in a way the user + * will notice + */ + if ( len < tot) + { + SSLerr(SSL_F_SSL3_WRITE_BYTES,SSL_R_BAD_LENGTH); + return(-1); + } + /* first check if there is a SSL3_BUFFER still being written * out. This will happen with non blocking IO */ if (wb->left != 0) @@ -816,20 +831,6 @@ int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len) return tot; } - /* ensure that if we end up with a smaller value of data to write - * out than the the original len from a write which didn't complete - * for non-blocking I/O and also somehow ended up avoiding - * the check for this in ssl3_write_pending/SSL_R_BAD_WRITE_RETRY as - * it must never be possible to end up with (len-tot) as a large - * number that will then promptly send beyond the end of the users - * buffer ... so we trap and report the error in a way the user - * will notice - */ - if ( len < tot) - { - SSLerr(SSL_F_SSL3_WRITE_BYTES,SSL_R_BAD_LENGTH); - return(-1); - } n=(len-tot); for (;;) -- 2.25.1