Improve speed of PBKDF2 by caching the digest state of the passphrase
@@ -243,13 +243,12 @@ int mbedtls_pkcs5_pbkdf2_hmac( mbedtls_md_context_t *ctx,
return( MBEDTLS_ERR_PKCS5_BAD_INPUT_DATA );
#endif
+ if( ( ret = mbedtls_md_hmac_starts( ctx, password, plen ) ) != 0 )
+ return( ret );
while( key_length )
{
// U1 ends up in work
//
- if( ( ret = mbedtls_md_hmac_starts( ctx, password, plen ) ) != 0 )
- return( ret );
-
if( ( ret = mbedtls_md_hmac_update( ctx, salt, slen ) ) != 0 )
return( ret );
@@ -259,21 +258,24 @@ int mbedtls_pkcs5_pbkdf2_hmac( mbedtls_md_context_t *ctx,
if( ( ret = mbedtls_md_hmac_finish( ctx, work ) ) != 0 )
return( ret );
+ if( ( ret = mbedtls_md_hmac_reset( ctx ) ) != 0 )
+ return( ret );
+
memcpy( md1, work, md_size );
for( i = 1; i < iteration_count; i++ )
{
// U2 ends up in md1
//
- if( ( ret = mbedtls_md_hmac_starts( ctx, password, plen ) ) != 0 )
- return( ret );
-
if( ( ret = mbedtls_md_hmac_update( ctx, md1, md_size ) ) != 0 )
return( ret );
if( ( ret = mbedtls_md_hmac_finish( ctx, md1 ) ) != 0 )
return( ret );
+ if( ( ret = mbedtls_md_hmac_reset( ctx ) ) != 0 )
+ return( ret );
+
// U1 xor U2
//
for( j = 0; j < md_size; j++ )
