Commit f85c9904 authored by Geoff Thorpe's avatar Geoff Thorpe
Browse files

Fix an oversight - when checking a potential session ID for conflicts with 

an SSL_CTX's session cache, it is necessary to compare the ssl_version at
the same time (a conflict is defined, courtesy of SSL_SESSION_cmp(), as a
matching id/id_length pair and a matching ssl_version). However, the
SSL_SESSION that will result from the current negotiation does not
necessarily have the same ssl version as the "SSL_METHOD" in use by the
SSL_CTX - part of the work in a handshake is to agree on an ssl version!

This is fixed by having the check function accept an SSL pointer rather
than the SSL_CTX it belongs to.

[Thanks to Lutz for illuminating the full extent of my stupidity]
parent 48bf4aae

ssl/ssl.h

+2 −2
Original line number Diff line number Diff line
@@ -391,7 +391,7 @@ typedef struct ssl_session_st 
 * callbacks should themselves check if the id they generate is unique otherwise

 * the SSL handshake will fail with an error - callbacks can do this using the

 * 'ssl' value they're passed by;

 *      SSL_CTX_has_matching_session_id(ssl->ctx, id, *id_len)

 *      SSL_has_matching_session_id(ssl, id, *id_len)

 * The length value passed in is set at the maximum size the session ID can be.

 * In SSLv2 this is 16 bytes, whereas SSLv3/TLSv1 it is 32 bytes. The callback

 * can alter this length to be less if desired, but under SSLv2 session IDs are
@@ -1054,7 +1054,7 @@ int SSL_CTX_add_session(SSL_CTX *s, SSL_SESSION *c); 
int	SSL_CTX_remove_session(SSL_CTX *,SSL_SESSION *c);

int	SSL_CTX_set_generate_session_id(SSL_CTX *, GEN_SESSION_CB);

int	SSL_set_generate_session_id(SSL *, GEN_SESSION_CB);

int	SSL_CTX_has_matching_session_id(const SSL_CTX *ctx, const unsigned char *id,

int	SSL_has_matching_session_id(const SSL *ssl, const unsigned char *id,

					unsigned int id_len);

SSL_SESSION *d2i_SSL_SESSION(SSL_SESSION **a,unsigned char **pp,long length);

ssl/ssl_lib.c

+4 −4
Original line number Diff line number Diff line
@@ -299,16 +299,16 @@ int SSL_set_generate_session_id(SSL *ssl, GEN_SESSION_CB cb) 
	return 1;

	}



int SSL_CTX_has_matching_session_id(const SSL_CTX *ctx, const unsigned char *id,

int SSL_has_matching_session_id(const SSL *ssl, const unsigned char *id,

				unsigned int id_len)

	{

	/* A quick examination of SSL_SESSION_hash and SSL_SESSION_cmp shows how

	 * we can "construct" a session to give us the desired check - ie. to

	 * find if there's a session in the hash table that would conflict with

	 * any new session built out of this id/id_len and the ssl_version in

	 * use by this SSL_CTX. */

	 * use by this SSL. */

	SSL_SESSION r, *p;

	r.ssl_version = ctx->method->version;

	r.ssl_version = ssl->version;

	r.session_id_length = id_len;

	memcpy(r.session_id, id, id_len);

	/* NB: SSLv2 always uses a fixed 16-byte session ID, so even if a
@@ -324,7 +324,7 @@ int SSL_CTX_has_matching_session_id(const SSL_CTX *ctx, const unsigned char *id, 
		}



	CRYPTO_r_lock(CRYPTO_LOCK_SSL_CTX);

	p = (SSL_SESSION *)lh_retrieve(ctx->sessions, &r);

	p = (SSL_SESSION *)lh_retrieve(ssl->ctx->sessions, &r);

	CRYPTO_r_unlock(CRYPTO_LOCK_SSL_CTX);

	return (p != NULL);

	}

ssl/ssl_sess.c

+2 −2
Original line number Diff line number Diff line
@@ -146,7 +146,7 @@ static int def_generate_session_id(const SSL *ssl, unsigned char *id, 
	unsigned int retry = 0;

	do

		RAND_pseudo_bytes(id, *id_len);

	while(SSL_CTX_has_matching_session_id(ssl->ctx, id, *id_len) &&

	while(SSL_has_matching_session_id(ssl, id, *id_len) &&

		(++retry < MAX_SESS_ID_ATTEMPTS));

	if(retry < MAX_SESS_ID_ATTEMPTS)

		return 1;
@@ -240,7 +240,7 @@ int ssl_get_new_session(SSL *s, int session) 
		else

			ss->session_id_length = tmp;

		/* Finally, check for a conflict */

		if(SSL_CTX_has_matching_session_id(s->ctx, ss->session_id,

		if(SSL_has_matching_session_id(s, ss->session_id,

						ss->session_id_length))

			{

			SSLerr(SSL_F_SSL_GET_NEW_SESSION,