commit 7040553a02ac1454a6b73044f9abd36274d34c08
author Krzysztof Stachowiak <krzysiek.stachowiak@gmail.com> Wed Mar 14 11:31:13 2018 +0100
committer Krzysztof Stachowiak <krzysiek.stachowiak@gmail.com> Wed Mar 14 14:35:12 2018 +0100
tree bb2006d9019ba03840ad7e9f5d761c30ab307227
parent 5273182a20e14e24707dbd3009d53fcb18eadb84

Add bounds check before length read

library/ssl_cli.c

diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index 94c521d..7bf9933 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -1850,6 +1850,12 @@
      *
      * opaque psk_identity_hint<0..2^16-1>;
      */
+    if( (*p) > end - 2 )
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message "
+                                    "(psk_identity_hint length)" ) );
+        return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
+    }
     len = (*p)[0] << 8 | (*p)[1];
     *p += 2;