test: add unit-tests for the crc module

Copied the unit-tests from phosphor-ipmi-blobs.  The CRC module there
will be dropped in favor of this one.

Change-Id: I875ec67820218c7b9d1feec8aee84cdbbe84df54
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/test/crc_unittest.cpp b/test/crc_unittest.cpp
new file mode 100644
index 0000000..3816bba
--- /dev/null
+++ b/test/crc_unittest.cpp
@@ -0,0 +1,42 @@
+#include <cstdint>
+#include <ipmiblob/crc.hpp>
+#include <string>
+#include <vector>
+
+#include <gtest/gtest.h>
+
+namespace ipmiblob
+{
+
+TEST(Crc16Test, VerifyCrcValue)
+{
+    // Verify the crc16 is producing the value we expect.
+
+    // Origin: security/crypta/ipmi/portable/ipmi_utils_test.cc
+    struct CrcTestVector
+    {
+        std::string input;
+        uint16_t output;
+    };
+
+    std::string longString =
+        "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
+        "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
+        "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
+        "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
+        "AAAAAAAAAAAAAAAA";
+
+    std::vector<CrcTestVector> vectors({{"", 0x1D0F},
+                                        {"A", 0x9479},
+                                        {"123456789", 0xE5CC},
+                                        {longString, 0xE938}});
+
+    for (const CrcTestVector& testVector : vectors)
+    {
+        std::vector<std::uint8_t> input;
+        input.insert(input.begin(), testVector.input.begin(),
+                     testVector.input.end());
+        EXPECT_EQ(generateCrc(input), testVector.output);
+    }
+}
+} // namespace ipmiblob