commit 4553dd46d6f82daaef9146789f377e0a885b3011
author gabor-mezei-arm <gabor.mezei@arm.com> Wed Aug 19 14:01:03 2020 +0200
committer gabor-mezei-arm <gabor.mezei@arm.com> Tue Aug 25 19:13:58 2020 +0200
tree 34c6c8b8bc7a76636bdc4fc0635ca80ae0418d30
parent 76749aea784cfec245390d0d6f0ab0a2d63ae90a

Force cleanup before return

Signed-off-by: gabor-mezei-arm <gabor.mezei@arm.com>

library/pkcs5.c

diff --git a/library/pkcs5.c b/library/pkcs5.c
index 049d27b..37cca00 100644
--- a/library/pkcs5.c
+++ b/library/pkcs5.c
@@ -223,7 +223,7 @@
                        unsigned int iteration_count,
                        uint32_t key_length, unsigned char *output )
 {
-    int ret, j;
+    int ret = 0, j;
     unsigned int i;
     unsigned char md1[MBEDTLS_MD_MAX_SIZE];
     unsigned char work[MBEDTLS_MD_MAX_SIZE];
@@ -247,16 +247,16 @@
         // U1 ends up in work
         //
         if( ( ret = mbedtls_md_hmac_update( ctx, salt, slen ) ) != 0 )
-            return( ret );
+            goto cleanup;
 
         if( ( ret = mbedtls_md_hmac_update( ctx, counter, 4 ) ) != 0 )
-            return( ret );
+            goto cleanup;
 
         if( ( ret = mbedtls_md_hmac_finish( ctx, work ) ) != 0 )
-            return( ret );
+            goto cleanup;
 
         if( ( ret = mbedtls_md_hmac_reset( ctx ) ) != 0 )
-           return( ret );
+            goto cleanup;
 
         memcpy( md1, work, md_size );
 
@@ -265,13 +265,13 @@
             // U2 ends up in md1
             //
             if( ( ret = mbedtls_md_hmac_update( ctx, md1, md_size ) ) != 0 )
-                return( ret );
+                goto cleanup;
 
             if( ( ret = mbedtls_md_hmac_finish( ctx, md1 ) ) != 0 )
-                return( ret );
+                goto cleanup;
 
             if( ( ret = mbedtls_md_hmac_reset( ctx ) ) != 0 )
-                return( ret );
+                goto cleanup;
 
             // U1 xor U2
             //
@@ -290,11 +290,12 @@
                 break;
     }
 
+cleanup:
     /* Zeroise buffers to clear sensitive data from memory. */
     mbedtls_platform_zeroize( work, MBEDTLS_MD_MAX_SIZE );
     mbedtls_platform_zeroize( md1, MBEDTLS_MD_MAX_SIZE );
 
-    return( 0 );
+    return( ret );
 }
 
 #if defined(MBEDTLS_SELF_TEST)