Add CRC64 (ECMA-182, reflected form polynomial) calculation

util/oc_crc.c

@@ -0,0 +1,50 @@
+/******************************************************************
+ *
+ * Copyright (c) 2023 plgd.dev s.r.o.
+ *
+ * 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 "util/oc_crc_internal.h"
+
+#ifdef OC_HAS_FEATURE_CRC64
+
+// ECMA-182, reflected form polynomial
+#define CRC64_POLYNOMIAL (0xC96C5795D7870F42ULL)
+
+static uint64_t
+crc64_update(uint64_t crc, uint8_t byte)
+{
+  crc ^= (uint64_t)byte;
+  for (int i = 0; i < 8; ++i) {
+    if (crc & 1) {
+      crc = (crc >> 1) ^ CRC64_POLYNOMIAL;
+    } else {
+      crc >>= 1;
+    }
+  }
+  return crc;
+}
+
+uint64_t
+oc_crc64(const uint8_t *buffer, size_t size)
+{
+  uint64_t crc = 0;
+  for (size_t i = 0; i < size; i++) {
+    crc = crc64_update(crc, buffer[i]);
+  }
+  return crc;
+}
+
+#endif /* OC_HAS_FEATURE_CRC64 */

util/oc_crc_internal.h

@@ -0,0 +1,49 @@
+/******************************************************************
+ *
+ * Copyright (c) 2023 plgd.dev s.r.o.
+ *
+ * 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.
+ *
+ ******************************************************************/
+
+#ifndef OC_CRC_INTERNAL_H
+#define OC_CRC_INTERNAL_H
+
+#include "util/oc_compiler.h"
+#include "util/oc_features.h"
+#include <stddef.h>
+#include <stdint.h>
+
+#ifdef OC_HAS_FEATURE_CRC64
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief Calculate CRC64 for a buffer of data.
+ *
+ * @param buffer The buffer of data to calculate CRC64 for (cannot be NULL);
+ * @param size The size of the buffer of data to calculate CRC64 for.
+ *
+ * @return The CRC64 value.
+ */
+uint64_t oc_crc64(const uint8_t *buffer, size_t size) OC_NONNULL();
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* OC_HAS_FEATURE_CRC64 */
+
+#endif /* OC_CRC_INTERNAL_H */

util/oc_features.h

@@ -62,4 +62,8 @@
 
 #endif /* OC_ETAG && OC_SERVER */
 
+#ifdef OC_HAS_FEATURE_ETAG
+#define OC_HAS_FEATURE_CRC64
+#endif /* OC_HAS_FEATURE_ETAG */
+
 #endif /* OC_FEATURES_H */

util/unittest/crc64test.cpp

@@ -0,0 +1,51 @@
+/****************************************************************************
+ *
+ * Copyright (c) 2023 plgd.dev s.r.o.
+ *
+ * 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 "util/oc_features.h"
+
+#ifdef OC_HAS_FEATURE_CRC64
+
+#include "util/oc_crc_internal.h"
+
+#include <gtest/gtest.h>
+
+TEST(TestCRC, CRC64)
+{
+  struct test
+  {
+    std::string input;
+    uint64_t crc;
+  };
+
+  std::vector<test> inputs{
+    { "", 0x0 },
+    { "Hello, World!", 0xA885B0FA12A6B582 },
+    { "1234567890", 0x4CCE99FD976EC1A8 },
+    { "Lorem ipsum dolor sit amet, consectetur adipiscing elit.",
+      0x9A076C1F9CFD879C },
+    { "IoTivity-Lite is the best IoT C library on the flat plane!",
+      0xB54B2DCA2CFA4D9E },
+  };
+
+  for (auto &input : inputs) {
+    EXPECT_EQ(input.crc,
+              oc_crc64((uint8_t *)&input.input[0], input.input.size()));
+  }
+}
+
+#endif /* OC_HAS_FEATURE_CRC64 */