commit 77d940170574fc4e347bc9bb363857269686d2bd
author gabor-mezei-arm <gabor.mezei@arm.com> Wed Aug 19 14:01:03 2020 +0200
committer gabor-mezei-arm <gabor.mezei@arm.com> Wed Sep 09 14:51:03 2020 +0200
tree ac044f7384d18650e3dc9098fcc669f2495a4709
parent 461c5a89dfd9cccd76815b2ce38e1edc501edf77

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 1533a92..7d392a6 100644
--- a/library/pkcs5.c
+++ b/library/pkcs5.c
@@ -252,7 +252,7 @@
                        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];
@@ -274,16 +274,16 @@
         // U1 ends up in work
         //
         if( ( ret = mbedtls_md_hmac_starts( ctx, password, plen ) ) != 0 )
-            return( ret );
+            goto cleanup;
 
         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;
 
         memcpy( md1, work, md_size );
 
@@ -292,13 +292,13 @@
             // U2 ends up in md1
             //
             if( ( ret = mbedtls_md_hmac_starts( ctx, password, plen ) ) != 0 )
-                return( ret );
+                goto cleanup;
 
             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;
 
             // U1 xor U2
             //
@@ -317,11 +317,12 @@
                 break;
     }
 
+cleanup:
     /* Zeroise buffers to clear sensitive data from memory. */
     mbedtls_zeroize( work, MBEDTLS_MD_MAX_SIZE );
     mbedtls_zeroize( md1, MBEDTLS_MD_MAX_SIZE );
 
-    return( 0 );
+    return( ret );
 }
 
 #if defined(MBEDTLS_SELF_TEST)