Merge pull request #21 from ericeberry/Issue_20

Issue 20: Fix cipher when bytes_to_process is 0

Author: mhabrat

reference/src/taimpl/src/ta_sa_crypto_cipher_process.c

@@ -30,9 +30,7 @@
 static size_t get_required_length(
         cipher_t* cipher,
         size_t bytes_to_process,
-        bool apply_padding,
-        sa_digest_algorithm digest_algorithm,
-        sa_digest_algorithm mgf1_digest_algorithm) {
+        bool apply_padding) {
     sa_cipher_algorithm cipher_algorithm = cipher_get_algorithm(cipher);
 
     switch (cipher_algorithm) {
@@ -415,23 +413,8 @@ sa_status ta_sa_crypto_cipher_process(
         }
 
         sa_cipher_mode cipher_mode = cipher_get_mode(cipher);
-        sa_digest_algorithm digest_algorithm;
-        sa_digest_algorithm mgf1_digest_algorithm;
-        const void* label;
-        size_t label_length;
-        status = cipher_get_oaep_parameters(cipher, &digest_algorithm, &mgf1_digest_algorithm, &label, &label_length);
-        if (status != SA_STATUS_OK) {
-            ERROR("cipher_get_oaep_parameters failed");
-            break;
-        }
-
         size_t required_length = get_required_length(cipher, *bytes_to_process,
-                !out && cipher_mode == SA_CIPHER_MODE_ENCRYPT, digest_algorithm, mgf1_digest_algorithm);
-        if (required_length == 0) {
-            status = SA_STATUS_INVALID_PARAMETER;
-            break;
-        }
-
+                !out && cipher_mode == SA_CIPHER_MODE_ENCRYPT);
         if (out == NULL) {
             *bytes_to_process = required_length;
             status = SA_STATUS_OK;