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Remove method-switching codepath in SSL_clear.

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Although the comment suggests this was added with an s->session check to
account for SSL_set_session switching methods (which we will remove in the next
commit) and to account for SSLv23_method switching methods (which we hope to
remove after a long tower of cleanup), the current codepath never runs and
can't work:

If it is called prior to handshaking or setting a session, no method switch has
happened so that codepath is dead. If it is called after setting a session, the
s->session check will keep it from running. If it is called after a handshake,
we will have established a session so that check will again keep it from
running. (Finally, if it is called during the handshake, the in_handshake check
will stop; that there is an SSL_clear call in the handshake state machine at
all is a bug that will be addressed once more things are disentangled. See
upstream's 979689aa5cfa100ccbc1f25064e9398be4b7b05c.)

Were that code to ever run, the SSL* would be in an inconsistent state. It
switches the method, but not the handshake_func. The handshake_func isn't
switched to NULL, so that will keep the SSL_connect and SSL_accept code from fixing it.

It seems the intent was that the caller would always call
SSL_set_{connect,accept}_state to fix this. But as of upstream's
b31b04d951e9b65bde29657e1ae057b76f0f0a73, this is not necessary and indeed
isn't called by a lot of consumer code.

Change-Id: I710652b1d565b77bc26f913c2066ce749a9025c9
Reviewed-on: https://boringssl-review.googlesource.com/2430
Reviewed-by: Adam Langley <agl@google.com>
This commit is contained in:
David Benjamin 2014-11-29 16:03:41 -05:00 committed by Adam Langley
parent 52d699f668
commit bb15e3ddb5
1 changed files with 1 additions and 13 deletions
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14
ssl/ssl_lib.c
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@ -234,19 +234,7 @@ int SSL_clear(SSL *s)
s->first_packet=0;
#if 1
/* Check to see if we were changed into a different method, if
* so, revert back if we are not doing session-id reuse. */
if (!s->in_handshake && (s->session == NULL) && (s->method != s->ctx->method))
{
s->method->ssl_free(s);
s->method=s->ctx->method;
if (!s->method->ssl_new(s))
return(0);
}
else
#endif
s->method->ssl_clear(s);
s->method->ssl_clear(s);
return(1);
}