Key wrapping memory optimization.

Change-Id: Ibf49fa12fc7f89554e5c00a0e84d0f832e686fcb

diff --git a/src/encrypt.c b/src/encrypt.c
index 03c515a..10400a4 100644 (file)
--- a/src/encrypt.c
+++ b/src/encrypt.c
@@ -276,13 +276,14 @@ int get_wrap_output_length(const yaca_context_h ctx, size_t input_len, size_t *o
                return YACA_ERROR_INVALID_PARAMETER;
        assert(c->cipher_ctx != NULL);
 
+       bool encryption = is_encryption_op(c->op_type);
        int type = EVP_CIPHER_type(c->cipher_ctx->cipher);
 
        if (input_len > 0) {
                if (type == NID_id_aes128_wrap || type == NID_id_aes192_wrap || type == NID_id_aes256_wrap) {
-                       *output_len = input_len + 8;
+                       *output_len = encryption ? input_len + 8 : input_len - 8;
                } else if (type == NID_id_smime_alg_CMS3DESwrap) {
-                       *output_len = input_len + 16;
+                       *output_len = encryption ? input_len + 16 : input_len - 16;
                } else {
                        assert(false);
                        return YACA_ERROR_INTERNAL;