// Copyright 2022 The Abseil Authors // // 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 // // https://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 "absl/crc/crc32c.h" #include #include #include #include #include #include #include "gtest/gtest.h" #include "absl/crc/internal/crc32c.h" #include "absl/strings/str_cat.h" #include "absl/strings/str_format.h" #include "absl/strings/string_view.h" namespace { TEST(CRC32C, RFC3720) { // Test the results of the vectors from // https://www.rfc-editor.org/rfc/rfc3720#appendix-B.4 char data[32]; // 32 bytes of ones. memset(data, 0, sizeof(data)); EXPECT_EQ(absl::ComputeCrc32c(absl::string_view(data, sizeof(data))), absl::crc32c_t{0x8a9136aa}); // 32 bytes of ones. memset(data, 0xff, sizeof(data)); EXPECT_EQ(absl::ComputeCrc32c(absl::string_view(data, sizeof(data))), absl::crc32c_t{0x62a8ab43}); // 32 incrementing bytes. for (int i = 0; i < 32; ++i) data[i] = static_cast(i); EXPECT_EQ(absl::ComputeCrc32c(absl::string_view(data, sizeof(data))), absl::crc32c_t{0x46dd794e}); // 32 decrementing bytes. for (int i = 0; i < 32; ++i) data[i] = static_cast(31 - i); EXPECT_EQ(absl::ComputeCrc32c(absl::string_view(data, sizeof(data))), absl::crc32c_t{0x113fdb5c}); // An iSCSI - SCSI Read (10) Command PDU. constexpr uint8_t cmd[48] = { 0x01, 0xc0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x14, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x00, 0x14, 0x00, 0x00, 0x00, 0x18, 0x28, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, }; EXPECT_EQ(absl::ComputeCrc32c(absl::string_view( reinterpret_cast(cmd), sizeof(cmd))), absl::crc32c_t{0xd9963a56}); } std::string TestString(size_t len) { std::string result; result.reserve(len); for (size_t i = 0; i < len; ++i) { result.push_back(static_cast(i % 256)); } return result; } TEST(CRC32C, Compute) { EXPECT_EQ(absl::ComputeCrc32c(""), absl::crc32c_t{0}); EXPECT_EQ(absl::ComputeCrc32c("hello world"), absl::crc32c_t{0xc99465aa}); } TEST(CRC32C, Extend) { uint32_t base = 0xC99465AA; // CRC32C of "Hello World" std::string extension = "Extension String"; EXPECT_EQ( absl::ExtendCrc32c(absl::crc32c_t{base}, extension), absl::crc32c_t{0xD2F65090}); // CRC32C of "Hello WorldExtension String" } TEST(CRC32C, ExtendByZeroes) { std::string base = "hello world"; absl::crc32c_t base_crc = absl::crc32c_t{0xc99465aa}; constexpr size_t kExtendByValues[] = {100, 10000, 100000}; for (const size_t extend_by : kExtendByValues) { SCOPED_TRACE(extend_by); absl::crc32c_t crc2 = absl::ExtendCrc32cByZeroes(base_crc, extend_by); EXPECT_EQ(crc2, absl::ComputeCrc32c(base + std::string(extend_by, '\0'))); } } TEST(CRC32C, UnextendByZeroes) { constexpr size_t kExtendByValues[] = {2, 200, 20000, 200000, 20000000}; constexpr size_t kUnextendByValues[] = {0, 100, 10000, 100000, 10000000}; for (auto seed_crc : {absl::crc32c_t{0}, absl::crc32c_t{0xc99465aa}}) { SCOPED_TRACE(seed_crc); for (const size_t size_1 : kExtendByValues) { for (const size_t size_2 : kUnextendByValues) { size_t extend_size = std::max(size_1, size_2); size_t unextend_size = std::min(size_1, size_2); SCOPED_TRACE(extend_size); SCOPED_TRACE(unextend_size); // Extending by A zeroes an unextending by B