return plaintext data faster on unpadded decryption
@@ -325,8 +325,10 @@ int mbedtls_cipher_update( mbedtls_cipher_context_t *ctx, const unsigned char *i
/*
* If there is not enough data for a full block, cache it.
*/
- if( ( ctx->operation == MBEDTLS_DECRYPT &&
+ if( ( ctx->operation == MBEDTLS_DECRYPT && NULL != ctx->add_padding &&
ilen <= block_size - ctx->unprocessed_len ) ||
+ ( ctx->operation == MBEDTLS_DECRYPT && NULL == ctx->add_padding &&
+ ilen < block_size - ctx->unprocessed_len ) ||
( ctx->operation == MBEDTLS_ENCRYPT &&
ilen < block_size - ctx->unprocessed_len ) )
{
@@ -372,9 +374,17 @@ int mbedtls_cipher_update( mbedtls_cipher_context_t *ctx, const unsigned char *i
return MBEDTLS_ERR_CIPHER_INVALID_CONTEXT;
}
+ /* Encryption: only cache partial blocks
+ * Decryption w/ padding: always keep at least one whole block
+ * Decryption w/o padding: only cache partial blocks
+ */
copy_len = ilen % block_size;
- if( copy_len == 0 && ctx->operation == MBEDTLS_DECRYPT )
+ if( copy_len == 0 &&
+ ctx->operation == MBEDTLS_DECRYPT &&
+ NULL != ctx->add_padding)
+ {
copy_len = block_size;
+ }
memcpy( ctx->unprocessed_data, &( input[ilen - copy_len] ),
copy_len );
