commit 73e7f4c0eec1108dd331224b65184bc3b61b10ff
author Gilles Peskine <Gilles.Peskine@arm.com> Fri May 05 19:24:06 2017 +0200
committer Simon Butcher <simon.butcher@arm.com> Mon May 15 13:58:45 2017 +0100
tree 721ea7901123c8823989b7e2642d096f92e5f183
parent 213aec86885befa99a2db3bdd2091438a9013706

RSA: wipe more stack buffers

MGF mask and PSS salt are not highly sensitive, but wipe them anyway
for good hygiene.

library/rsa.c

diff --git a/library/rsa.c b/library/rsa.c
index 09477cb..8d7e9e6 100644
--- a/library/rsa.c
+++ b/library/rsa.c
@@ -492,6 +492,8 @@
 
         dlen -= use_len;
     }
+
+    polarssl_zeroize( mask, sizeof( mask ) );
 }
 #endif /* POLARSSL_PKCS1_V21 */
 
@@ -1011,6 +1013,7 @@
     if( ( ret = md_init_ctx( &md_ctx, md_info ) ) != 0 )
     {
         md_free( &md_ctx );
+        /* No need to zeroize salt: we didn't use it. */
         return( ret );
     }
 
@@ -1021,6 +1024,7 @@
     md_update( &md_ctx, hash, hashlen );
     md_update( &md_ctx, salt, slen );
     md_finish( &md_ctx, p );
+    polarssl_zeroize( salt, sizeof( salt ) );
 
     // Compensate for boundary condition when applying mask
     //