From 39c1f3b3559d7fe659a6fe05d5ac5c752501ed37 Mon Sep 17 00:00:00 2001
From: Mark Haines <mark.haines@matrix.org>
Date: Fri, 24 Jul 2015 14:29:52 +0100
Subject: Add methods for computing sha256 hashes and validating ed25519
 signatures

---
 src/utility.cpp | 57 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 src/utility.cpp

(limited to 'src/utility.cpp')

diff --git a/src/utility.cpp b/src/utility.cpp
new file mode 100644
index 0000000..1d8c5c1
--- /dev/null
+++ b/src/utility.cpp
@@ -0,0 +1,57 @@
+/* Copyright 2015 OpenMarket Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "olm/utility.hh"
+#include "olm/crypto.hh"
+
+
+olm::Utility::Utility(
+) : last_error(olm::ErrorCode::SUCCESS) {
+}
+
+
+size_t olm::Utility::sha256_length() {
+    return olm::HMAC_SHA256_OUTPUT_LENGTH;
+}
+
+
+size_t olm::Utility::sha256(
+    std::uint8_t const * input, std::size_t input_length,
+    std::uint8_t * output, std::size_t output_length
+) {
+    if (output_length < sha256_length()) {
+        last_error = olm::ErrorCode::OUTPUT_BUFFER_TOO_SMALL;
+        return std::size_t(-1);
+    }
+    olm::sha256(input, input_length, output);
+    return 32;
+}
+
+
+size_t olm::Utility::ed25519_verify(
+    Ed25519PublicKey const & key,
+    std::uint8_t const * message, std::size_t message_length,
+    std::uint8_t const * signature, std::size_t signature_length
+) {
+    if (signature_length < 64) {
+        last_error = olm::ErrorCode::BAD_MESSAGE_MAC;
+        return std::size_t(-1);
+    }
+    if (!olm::ed25519_verify(key, message, message_length, signature)) {
+        last_error = olm::ErrorCode::BAD_MESSAGE_MAC;
+        return std::size_t(-1);
+    }
+    return std::size_t(0);
+}
-- 
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