Add tests for ec_util

Remove ComputeSharedEcdh function because: + It's moved to subtle_util_boringssl + It's not used any more and it's not carefully tested. PiperOrigin-RevId: 202044794 GitOrigin-RevId: 2248584d3263c9382471b3f5028a5de506e1d6ff
sixh · Jun 27, 2018 · 507da6a · 507da6a
1 parent 250cb6a
commit 507da6a
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Showing 3 changed files with 35 additions and 80 deletions.
diff --git a/cc/subtle/ec_util.cc b/cc/subtle/ec_util.cc
@@ -30,23 +30,6 @@ namespace crypto {
 namespace tink {
 namespace subtle {
 
-// static
-crypto::tink::util::StatusOr<std::string> EcUtil::ComputeEcdhSharedSecret(
-    EllipticCurveType curve_type, absl::string_view priv,
-    absl::string_view pub_x, absl::string_view pub_y) {
-  bssl::UniquePtr<BIGNUM> priv_key(
-      BN_bin2bn(reinterpret_cast<const unsigned char *>(priv.data()),
-                priv.size(), nullptr));
-  auto status_or_ec_point =
-      SubtleUtilBoringSSL::GetEcPoint(curve_type, pub_x, pub_y);
-  if (!status_or_ec_point.ok()) {
-    return status_or_ec_point.status();
-  }
-  bssl::UniquePtr<EC_POINT> pub_key(status_or_ec_point.ValueOrDie());
-  return SubtleUtilBoringSSL::ComputeEcdhSharedSecret(
-      curve_type, priv_key.get(), pub_key.get());
-}
-
 // static
 uint32_t EcUtil::FieldSizeInBytes(EllipticCurveType curve_type) {
   auto ec_group_result = SubtleUtilBoringSSL::GetEcGroup(curve_type);

diff --git a/cc/subtle/ec_util.h b/cc/subtle/ec_util.h
@@ -28,16 +28,6 @@ namespace subtle {
 
 class EcUtil {
  public:
-  // Computes and returns the ECDH shared secret, which is the x-coordinate of
-  // the shared point, from a private key and a public key.
-  // Returns an error if the public key is not a valid point on the private
-  // key's curve.
-  static crypto::tink::util::StatusOr<std::string> ComputeEcdhSharedSecret(
-      EllipticCurveType curve_type,
-      absl::string_view priv,
-      absl::string_view pub_x,
-      absl::string_view pub_y);
-
   // Returns the encoding size of a point on the specified elliptic curve
   // when the given 'point_format' is used.
   static crypto::tink::util::StatusOr<uint32_t> EncodingSizeInBytes(

diff --git a/cc/subtle/ec_util_test.cc b/cc/subtle/ec_util_test.cc
@@ -14,6 +14,7 @@
 //
 ////////////////////////////////////////////////////////////////////////////////
 
+#include "tink/subtle/common_enums.h"
 #include "tink/subtle/ec_util.h"
 #include "tink/util/status.h"
 #include "tink/util/statusor.h"
@@ -25,62 +26,43 @@ namespace tink {
 namespace subtle {
 namespace {
 
-// TODO(quannguyen): Add extensive tests.
-class EcUtilTest : public ::testing::Test {};
+TEST(EcUtilTest, testFieldSizeInBytes) {
+  EXPECT_EQ(256/8, EcUtil::FieldSizeInBytes(EllipticCurveType::NIST_P256));
+  EXPECT_EQ(384/8, EcUtil::FieldSizeInBytes(EllipticCurveType::NIST_P384));
+  EXPECT_EQ((521 + 7)/8,
+            EcUtil::FieldSizeInBytes(EllipticCurveType::NIST_P521));
 
-// Test vectors from
-// http://csrc.nist.gov/groups/STM/cavp/component-testing.html#ecc-cdh.
-struct TestVector {
-  std::string pubx_hex;
-  std::string puby_hex;
-  std::string priv_hex;
-  std::string shared_hex;
-  EllipticCurveType curve;
-};
-
-static const std::vector<TestVector> test_vector(
-    {{"700c48f77f56584c5cc632ca65640db91b6bacce3a4df6b42ce7cc838833d287",
-      "db71e509e3fd9b060ddb20ba5c51dcc5948d46fbf640dfe0441782cab85fa4ac",
-      "7d7dc5f71eb29ddaf80d6214632eeae03d9058af1fb6d22ed80badb62bc1a534",
-      "46fc62106420ff012e54a434fbdd2d25ccc5852060561e68040dd7778997bd7b",
-      EllipticCurveType::NIST_P256},
-     {"a7c76b970c3b5fe8b05d2838ae04ab47697b9eaf52e764592efda27fe7513272734466b4"
-      "00091adbf2d68c58e0c50066",
-      "ac68f19f2e1cb879aed43a9969b91a0839c4c38a49749b661efedf243451915ed0905a32"
-      "b060992b468c64766fc8437a",
-      "3cc3122a68f0d95027ad38c067916ba0eb8c38894d22e1b15618b6818a661774ad463b20"
-      "5da88cf699ab4d43c9cf98a1",
-      "5f9d29dc5e31a163060356213669c8ce132e22f57c9a04f40ba7fcead493b457e5621e76"
-      "6c40a2e3d4d6a04b25e533f1",
-      EllipticCurveType::NIST_P384},
-     {"000000685a48e86c79f0f0875f7bc18d25eb5fc8c0b07e5da4f4370f3a9490340854334b"
-      "1e1b87fa395464c60626124a4e70d0f785601d37c09870ebf176666877a2046d",
-      "000001ba52c56fc8776d9e8f5db4f0cc27636d0b741bbe05400697942e80b739884a83bd"
-      "e99e0f6716939e632bc8986fa18dccd443a348b6c3e522497955a4f3c302f676",
-      "0000017eecc07ab4b329068fba65e56a1f8890aa935e57134ae0ffcce802735151f4eac6"
-      "564f6ee9974c5e6887a1fefee5743ae2241bfeb95d5ce31ddcb6f9edb4d6fc47",
-      "005fc70477c3e63bc3954bd0df3ea0d1f41ee21746ed95fc5e1fdf90930d5e136672d72c"
-      "c770742d1711c3c3a4c334a0ad9759436a4d3c5bf6e74b9578fac148c831",
-      EllipticCurveType::NIST_P521}});
+  EXPECT_EQ(0, EcUtil::FieldSizeInBytes(EllipticCurveType::UNKNOWN_CURVE));
+}
 
-TEST_F(EcUtilTest, testBasic) {
-  for (const TestVector& test : test_vector) {
-    std::string pubx = test::HexDecodeOrDie(test.pubx_hex);
-    std::string puby = test::HexDecodeOrDie(test.puby_hex);
-    std::string priv = test::HexDecodeOrDie(test.priv_hex);
-    std::string shared = test::HexDecodeOrDie(test.shared_hex);
-    auto computed_shared =
-        EcUtil::ComputeEcdhSharedSecret(test.curve, priv, pubx, puby);
-    EXPECT_TRUE(computed_shared.ok());
-    EXPECT_EQ(test.shared_hex, test::HexEncode(computed_shared.ValueOrDie()));
+TEST(EcUtilTest, testEncodingSizeInBytes) {
+  EXPECT_EQ(2 * (256/8) + 1,
+            EcUtil::EncodingSizeInBytes(EllipticCurveType::NIST_P256,
+                                        EcPointFormat::UNCOMPRESSED)
+            .ValueOrDie());
+  EXPECT_EQ(256/8 + 1,
+            EcUtil::EncodingSizeInBytes(EllipticCurveType::NIST_P256,
+                                        EcPointFormat::COMPRESSED)
+            .ValueOrDie());
+  EXPECT_EQ(2 * (384/8) + 1,
+            EcUtil::EncodingSizeInBytes(EllipticCurveType::NIST_P384,
+                                        EcPointFormat::UNCOMPRESSED)
+            .ValueOrDie());
+  EXPECT_EQ(384/8 + 1,
+            EcUtil::EncodingSizeInBytes(EllipticCurveType::NIST_P384,
+                                        EcPointFormat::COMPRESSED)
+            .ValueOrDie());
+  EXPECT_EQ(2 * ((521 + 7)/8) + 1,
+            EcUtil::EncodingSizeInBytes(EllipticCurveType::NIST_P521,
+                                        EcPointFormat::UNCOMPRESSED)
+            .ValueOrDie());
+  EXPECT_EQ((521 + 7)/8 + 1,
+            EcUtil::EncodingSizeInBytes(EllipticCurveType::NIST_P521,
+                                        EcPointFormat::COMPRESSED)
+            .ValueOrDie());
 
-    // Modify the y coordinate of public key.
-    puby = puby.substr(0, puby.length() - 1) +
-           static_cast<char>(puby[puby.length() - 1] + 1);
-    auto modified_shared =
-        EcUtil::ComputeEcdhSharedSecret(test.curve, priv, pubx, puby);
-    EXPECT_FALSE(modified_shared.ok());
-  }
+  EXPECT_FALSE(EcUtil::EncodingSizeInBytes(EllipticCurveType::NIST_P256,
+                                           EcPointFormat::UNKNOWN_FORMAT).ok());
 }
 
 }  // namespace