Remove a reachable assert from ssl3_write_bytes

A buggy application that call SSL_write with a different length after a
NBIO event could cause an OPENSSL_assert to be reached. The assert is not
actually necessary because there was an explicit check a little further
down that would catch this scenario. Therefore remove the assert an move
the check a little higher up.

Reviewed-by: Rich Salz <rsalz@openssl.org>
This commit is contained in:
Matt Caswell 2015-10-30 17:01:01 +00:00
parent 6929b4477b
commit 1c2e5d560d

View File

@ -455,8 +455,22 @@ int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len)
}
s->rwstate = SSL_NOTHING;
OPENSSL_assert(s->rlayer.wnum <= INT_MAX);
tot = s->rlayer.wnum;
/*
* 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 ((unsigned int)len < s->rlayer.wnum) {
SSLerr(SSL_F_SSL3_WRITE_BYTES, SSL_R_BAD_LENGTH);
return -1;
}
s->rlayer.wnum = 0;
if (SSL_in_init(s) && !ossl_statem_get_in_handshake(s)) {
@ -469,20 +483,6 @@ 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