Fix potential bad read in parsing ServerHello
diff --git a/ChangeLog b/ChangeLog
index 4d6b7de..dd1a3c5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -7,6 +7,10 @@
(server is not affected if it doesn't ask for a client certificate).
(Found using Codenomicon Defensics.)
+Bugfix
+ * Fix potential bad read in parsing ServerHello (found by Adrien
+ Vialletelle).
+
Changes
* X.509 certificates with more than one AttributeTypeAndValue per
RelativeDistinguishedName are not accepted any more.
diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index 15fc554..032e506 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -377,7 +377,7 @@
#endif
int ret, i, comp;
size_t n;
- size_t ext_len = 0;
+ size_t ext_len;
unsigned char *buf, *ext;
int renegotiation_info_seen = 0;
int handshake_failure = 0;
@@ -464,7 +464,7 @@
* 42+n . 43+n extensions length
* 44+n . 44+n+m extensions
*/
- if( ssl->in_hslen > 42 + n )
+ if( ssl->in_hslen > 43 + n )
{
ext_len = ( ( buf[42 + n] << 8 )
| ( buf[43 + n] ) );
@@ -476,6 +476,15 @@
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO );
}
}
+ else if( ssl->in_hslen == 42 + n )
+ {
+ ext_len = 0;
+ }
+ else
+ {
+ SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO );
+ }
i = ( buf[39 + n] << 8 ) | buf[40 + n];
comp = buf[41 + n];