// Copyright 2026 Google LLC
//
// 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 "crypto/default/x509_certificate.h"

#include <string>
#include <utility>
#include <vector>

#include "absl/log/absl_check.h"
#include "absl/log/check.h"
#include "absl/status/status.h"
#include "absl/status/status_matchers.h"
#include "absl/strings/escaping.h"
#include "absl/strings/string_view.h"
#include "absl/time/time.h"
#include "crypto/algorithms.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "openssl/asn1.h"
#include "openssl/base.h"
#include "openssl/mem.h"
#include "openssl/obj.h"
#include "openssl/x509.h"
#include "proto/common.pb.h"
#include "tink/signature/ecdsa_parameters.h"
#include "tink/signature/ed25519_parameters.h"
#include "tink/signature/rsa_ssa_pss_parameters.h"

namespace credentio {
namespace {

using ::absl_testing::IsOk;
using ::absl_testing::IsOkAndHolds;
using ::absl_testing::StatusIs;
using ::crypto::tink::EcdsaParameters;
using ::crypto::tink::Ed25519Parameters;
using ::crypto::tink::RsaSsaPssParameters;
using ::testing::ElementsAre;
using ::testing::HasSubstr;
using ::testing::IsEmpty;
using ::testing::NotNull;

constexpr absl::string_view kDerRsaBase64 =
    "MIIGDDCCA/SgAwIBAgIQf/"
    "J0H9HG3kO1lHqOZXCenjANBgkqhkiG9w0BAQsFADB1MQswCQYDVQQGEwJVUzEjMCEGA1UEChMa"
    "QWRvYmUgU3lzdGVtcyBJbmNvcnBvcmF0ZWQxHTAbBgNVBAsTFEFkb2JlIFRydXN0IFNlcnZpY2"
    "VzMSIwIAYDVQQDExlBZG9iZSBQcm9kdWN0IFNlcnZpY2VzIEczMB4XDTI0MDExMTAwMDAwMFoX"
    "DTI1MDExMDIzNTk1OVowfzERMA8GA1UEAwwIY2FpLXByb2QxEzARBgNVBAoMCkFkb2JlIEluYy"
    "4xETAPBgNVBAcMCFNhbiBKb3NlMRMwEQYDVQQIDApDYWxpZm9ybmlhMQswCQYDVQQGEwJVUzEg"
    "MB4GCSqGSIb3DQEJARYRY2FpLW9wc0BhZG9iZS5jb20wggEiMA0GCSqGSIb3DQEBAQUAA4IBDw"
    "AwggEKAoIBAQDv0wCnfYY9lkHDsykrTG7FYlnYHBcyualuD5u9ULjzv+"
    "FsTWOLg8Nhrz9RTxI9EeBbu3Wm7f4vqPsQYfxkEp0wIa6DVmEOZhbAeRfbhybWQ/"
    "D4Wvvck4mEZR+QZmTpIn7HX61gbtMFHlJUxkYBctIoAt9TBAFbz9d5Ig2WG0bsH39b6/"
    "8USXnIIk4FB6dtBRT1xeEwSDtwOd1YBpXXNBJmRWHXNJZZ85of2tBTesg/"
    "kMvTrOJJxYDZ97U416wcvbVomlees+NXUY3/"
    "ZB4xH+"
    "NsZils7m1bL2v2hSnHiLoqZeUKklbHUmT4ZpjrZCdtuIsWm5j2PPXKr7HKUuCbZSXBAgMBAAWj"
    "ggGMMIIBiDAMBgNVHRMBAf8EAjAAMA4GA1UdDwEB/"
    "wQEAwIHgDAeBgNVHSUEFzAVBgkqhkiG9y8BAQwGCCsGAQUFBwMEMIGOBgNVHSAEgYYwgYMwgYA"
    "GCSqGSIb3LwECAzBzMHEGCCsGAQUFBwICMGUMY1lvdSBhcmUgbm90IHBlcm1pdHRlZCB0byB1c"
    "2UgdGhpcyBMaWNlbnNlIENlcnRpZmljYXRlIGV4Y2VwdCBhcyBwZXJtaXR0ZWQgYnkgdGhlIGx"
    "pY2Vuc2UgYWdyZWVtZW50LjBdBgNVHR8EVjBUMFKgUKBOhkxodHRwOi8vcGtpLWNybC5zeW1hd"
    "XRoLmNvbS9jYV83YTVjM2EwYzczMTE3NDA2YWRkMTkzMTJiYzFiYzIzZi9MYXRlc3RDUkwuY3J"
    "sMDcGCCsGAQUFBwEBBCswKTAnBggrBgEFBQcwAYYbaHR0cDovL3BraS1vY3NwLnN5bWF1dGguY"
    "29tMB8GA1UdIwQYMBaAFFcpejJNzP7kNU7AHyRzznNTq99qMA0GCSqGSIb3DQEBCwUAA4ICAQA"
    "hY9X822Lvow9+KlSdkAI/95WsS/"
    "n1Y5se5YJkePUHLxsablSaNOA9BiVfJOPxcT+JjbumGCseDSmIOxYPO7mzwHpMqRoyZS+"
    "C2T5SC6TJtt920ELoq+"
    "0aDLjRw7gOQRSg8OK0PFPWKBtCp0qiAChUqoMRWqcX4IVBDO1sZxmEUj1cpOwJDB/"
    "2HDsuEkKjqMA0EgAE3JC1LBYik95IQmE9WBYvIp6mBDEkyovqyBhnEar2kJJCfaBLylp/"
    "JAUsHJnAQEP8PHK1FlkvpvdleoX59lmwT1+wHGlxYWK/"
    "ykW+AFA60LOVJt8byjtuAE8lebuYADyPe3eEMR4THQbHwH/"
    "1rz2nNN5tZWsPdIR7S5mX0RtUL74XgSixEkV1jDO4/"
    "WIk7V3kjdXEZr0WtWr8VgEY5G+"
    "8NpPBqd2LMLBp7jejMIj3tA8RS1L6MnO3PWRqkdwGwsCHsvGcTzauWarWji990WxBTPscSk6Q8"
    "WTIqiHI9OfUUiriWQkpfeMEDo1r+zHJRmj26+"
    "zgID7QB41xNeV3K6BFQX6ayl1swuIh26KB0Mu74sndRzG+8tMTffvjBoO9QPW/"
    "OtdWyYmsLGT0Kcj9EaaIg1JmgNtRBwo9f89eYJSYwenQ+GddpqdnBIjk63Q+K3gCdlpTs++"
    "tJCZ7DX9yndmYlx94HgUZFPcNimun6Q==";

constexpr absl::string_view kDerEcdsaBase64 =
    "MIIChzCCAi6gAwIBAgIUcCTmJHYF8dZfG0d1UdT6/"
    "LXtkeYwCgYIKoZIzj0EAwIwgYwxCzAJBgNVBAYTAlVTMQswCQYDVQQIDAJDQTESMBAGA1UEBww"
    "JU29tZXdoZXJlMScwJQYDVQQKDB5DMlBBIFRlc3QgSW50ZXJtZWRpYXRlIFJvb3QgQ0ExGTAXB"
    "gNVBAsMEEZPUiBURVNUSU5HX09OTFkxGDAWBgNVBAMMD0ludGVybWVkaWF0ZSBDQTAeFw0yMjA"
    "2MTAxODQ2NDBaFw0zMDA4MjYxODQ2NDBaMIGAMQswCQYDVQQGEwJVUzELMAkGA1UECAwCQ0ExE"
    "jAQBgNVBAcMCVNvbWV3aGVyZTEfMB0GA1UECgwWQzJQQSBUZXN0IFNpZ25pbmcgQ2VydDEZMBc"
    "GA1UECwwQRk9SIFRFU1RJTkdfT05MWTEUMBIGA1UEAwwLQzJQQSBTaWduZXIwWTATBgcqhkjOP"
    "QIBBggqhkjOPQMBBwNCAAQPaL6RkAkYkKU4+IryBSYxJM3h77sFiMrbvbI8fG7w2Bbl9otNG/"
    "cch3DAw5rGAPV7NWkyl3QGuV/wt0MrAPDoo3gwdjAMBgNVHRMBAf8EAjAAMBYGA1UdJQEB/"
    "wQMMAoGCCsGAQUFBwMEMA4GA1UdDwEB/"
    "wQEAwIGwDAdBgNVHQ4EFgQUFznP0y83joiNOCedQkxTtAMyNcowHwYDVR0jBBgwFoAUDnyNcma"
    "/osnlAJTvtW6A4rYOL2swCgYIKoZIzj0EAwIDRwAwRAIgOY/2szXjslg/"
    "MyJFZ2y7OH8giPYTsvS7UPRP9GI9NgICIDQPMKrELQUJEtipZ0TqvI/"
    "4mieoyRCeIiQtyuS0LACz";

// Base64 encoded string of DER bytes of an X.509 certificate signed with
// Ed25519 algorithm, which is generated by following commands:
//
// openssl genpkey -algorithm Ed25519 -outform PEM -out private.pem
// openssl pkey -in private.pem -pubout -outform PEM -out public.pem
// openssl req -x509 -key private.pem -out cert.pem -days 99999
// openssl x509 -in cert.pem -outform DER -out cert.der
// cat cert.der | base64
//
// This certificate is self-signed on 2024-09-18 and it will expire on
// 2298-07-03. So, if this code is still around in 2298 and you wonder why your
// test that relies on this certificate being valid fails, please update your
// test certificate.

constexpr absl::string_view kDerEdBase64 =
    "MIIBoTCCAVOgAwIBAgIUZnrWsn3k+"
    "VyZMdOt2jHxA4Z6QNIwBQYDK2VwMEUxCzAJBgNVBAYTAkFVMRMwEQYDVQQIDApTb21lLVN0YXR"
    "lMSEwHwYDVQQKDBhJbnRlcm5ldCBXaWRnaXRzIFB0eSBMdGQwIBcNMjQwOTE4MTkxMTMyWhgPM"
    "jI5ODA3MDMxOTExMzJaMEUxCzAJBgNVBAYTAkFVMRMwEQYDVQQIDApTb21lLVN0YXRlMSEwHwY"
    "DVQQKDBhJbnRlcm5ldCBXaWRnaXRzIFB0eSBMdGQwKjAFBgMrZXADIQAYkLGZHs4BuUq11RLkR"
    "V3lX6U1CMxpkKMI3dFBkQjDFKNTMFEwHQYDVR0OBBYEFPl9A331I54qf4vhLTs5KZqsJznSMB8"
    "GA1UdIwQYMBaAFPl9A331I54qf4vhLTs5KZqsJznSMA8GA1UdEwEB/"
    "wQFMAMBAf8wBQYDK2VwA0EAxWKyUVcH4hoW/"
    "mS66Ot4UGqaEKUANiyT6khvcUZLUpM2m7Cmh7ZwmjBz7b6X9nqHwd+8WnSMUZHKL5bLmZmsDw="
    "=";

// Base64 encoded string of the signature obtained by running the following
// commands:
//
// openssl pkeyutl -sign -inkey private.pem -rawin -in data.txt -out sig.bin
// cat sig.bin | base64
//
// where data.txt contains the text "test data" (without a new line).
constexpr absl::string_view kEdSignatureBase64 =
    "wB5+rUKWp47TZ8VPpUlA32IO033ggYB63qXLPyb8bDEGJyD8TBM/"
    "psRxl5Z8EsglhzdmvB29VL62xp4+3On/Bg==";

std::string Base64Unescape(absl::string_view base64) {
  std::string bytes;
  ABSL_CHECK(absl::Base64Unescape(base64, &bytes));
  return bytes;
}

TEST(X509CertificateTest, GetPemKeyParamsForRsaKey) {
  auto x509 = X509Certificate::Create(Base64Unescape(kDerRsaBase64));
  ABSL_ASSERT_OK(x509.status());

  const crypto::tink::BigInteger exponent(std::string("\001\000\005", 3));

  absl::StatusOr<std::vector<X509Certificate::TinkKeyParameters>> params_ps256 =
      (*x509)->GetPemKeyParams(SigningAlgorithm::kPs256);
  ABSL_ASSERT_OK(params_ps256.status());
  absl::StatusOr<RsaSsaPssParameters> want_ps256_params =
      RsaSsaPssParameters::Builder()
          .SetModulusSizeInBits(2048)
          .SetPublicExponent(exponent)
          .SetMgf1HashType(RsaSsaPssParameters::HashType::kSha256)
          .SetSigHashType(RsaSsaPssParameters::HashType::kSha256)
          .SetSaltLengthInBytes(32)
          .SetVariant(RsaSsaPssParameters::Variant::kNoPrefix)
          .Build();
  ABSL_ASSERT_OK(want_ps256_params.status());
  EXPECT_THAT(*params_ps256, ElementsAre(*want_ps256_params));

  absl::StatusOr<std::vector<X509Certificate::TinkKeyParameters>> params_ps384 =
      (*x509)->GetPemKeyParams(SigningAlgorithm::kPs384);
  ABSL_ASSERT_OK(params_ps384.status());
  absl::StatusOr<RsaSsaPssParameters> want_ps384_params =
      RsaSsaPssParameters::Builder()
          .SetModulusSizeInBits(2048)
          .SetPublicExponent(exponent)
          .SetMgf1HashType(RsaSsaPssParameters::HashType::kSha384)
          .SetSigHashType(RsaSsaPssParameters::HashType::kSha384)
          .SetVariant(RsaSsaPssParameters::Variant::kNoPrefix)
          .SetSaltLengthInBytes(48)
          .Build();
  ABSL_ASSERT_OK(want_ps384_params.status());
  EXPECT_THAT(*params_ps384, ElementsAre(*want_ps384_params));

  absl::StatusOr<std::vector<X509Certificate::TinkKeyParameters>> params_ps512 =
      (*x509)->GetPemKeyParams(SigningAlgorithm::kPs512);
  ABSL_ASSERT_OK(params_ps512.status());
  absl::StatusOr<RsaSsaPssParameters> want_ps512_params =
      RsaSsaPssParameters::Builder()
          .SetModulusSizeInBits(2048)
          .SetPublicExponent(exponent)
          .SetMgf1HashType(RsaSsaPssParameters::HashType::kSha512)
          .SetSigHashType(RsaSsaPssParameters::HashType::kSha512)
          .SetVariant(RsaSsaPssParameters::Variant::kNoPrefix)
          .SetSaltLengthInBytes(64)
          .Build();
  ABSL_ASSERT_OK(want_ps512_params.status());
  EXPECT_THAT(*params_ps512, ElementsAre(*want_ps512_params));

  EXPECT_THAT((*x509)->GetPemKeyParams(SigningAlgorithm::kEs256),
              StatusIs(absl::StatusCode::kInvalidArgument,
                       HasSubstr("Wrong key type")));
  EXPECT_THAT((*x509)->GetPemKeyParams(SigningAlgorithm::kEdDsa),
              StatusIs(absl::StatusCode::kInvalidArgument,
                       HasSubstr("Wrong key type")));
}

TEST(X509CertificateTest, GetPemKeyParamsForEcdsaKey) {
  auto x509 = X509Certificate::Create(Base64Unescape(kDerEcdsaBase64));
  ABSL_ASSERT_OK(x509.status());

  absl::StatusOr<std::vector<X509Certificate::TinkKeyParameters>> params_es256 =
      (*x509)->GetPemKeyParams(SigningAlgorithm::kEs256);
  ABSL_ASSERT_OK(params_es256.status());
  absl::StatusOr<EcdsaParameters> want_p256_der_ecdsa_params =
      EcdsaParameters::Builder()
          .SetCurveType(EcdsaParameters::CurveType::kNistP256)
          .SetHashType(EcdsaParameters::HashType::kSha256)
          .SetSignatureEncoding(EcdsaParameters::SignatureEncoding::kDer)
          .SetVariant(EcdsaParameters::Variant::kNoPrefix)
          .Build();
  ABSL_ASSERT_OK(want_p256_der_ecdsa_params.status());
  absl::StatusOr<EcdsaParameters> want_p256_ieee_ecdsa_params =
      EcdsaParameters::Builder()
          .SetCurveType(EcdsaParameters::CurveType::kNistP256)
          .SetHashType(EcdsaParameters::HashType::kSha256)
          .SetSignatureEncoding(EcdsaParameters::SignatureEncoding::kIeeeP1363)
          .SetVariant(EcdsaParameters::Variant::kNoPrefix)
          .Build();
  ABSL_ASSERT_OK(want_p256_ieee_ecdsa_params.status());
  EXPECT_THAT(*params_es256, ElementsAre(*want_p256_ieee_ecdsa_params,
                                         *want_p256_der_ecdsa_params));

  absl::StatusOr<std::vector<X509Certificate::TinkKeyParameters>> params_es384 =
      (*x509)->GetPemKeyParams(SigningAlgorithm::kEs384);
  ABSL_ASSERT_OK(params_es384.status());
  absl::StatusOr<EcdsaParameters> want_p384_der_ecdsa_params =
      EcdsaParameters::Builder()
          .SetCurveType(EcdsaParameters::CurveType::kNistP384)
          .SetHashType(EcdsaParameters::HashType::kSha384)
          .SetSignatureEncoding(EcdsaParameters::SignatureEncoding::kDer)
          .SetVariant(EcdsaParameters::Variant::kNoPrefix)
          .Build();
  ABSL_ASSERT_OK(want_p384_der_ecdsa_params.status());
  absl::StatusOr<EcdsaParameters> want_p384_ieee_ecdsa_params =
      EcdsaParameters::Builder()
          .SetCurveType(EcdsaParameters::CurveType::kNistP384)
          .SetHashType(EcdsaParameters::HashType::kSha384)
          .SetSignatureEncoding(EcdsaParameters::SignatureEncoding::kIeeeP1363)
          .SetVariant(EcdsaParameters::Variant::kNoPrefix)
          .Build();
  ABSL_ASSERT_OK(want_p384_ieee_ecdsa_params.status());
  EXPECT_THAT(*params_es384, ElementsAre(*want_p384_ieee_ecdsa_params,
                                         *want_p384_der_ecdsa_params));

  absl::StatusOr<std::vector<X509Certificate::TinkKeyParameters>> params_es521 =
      (*x509)->GetPemKeyParams(SigningAlgorithm::kEs512);
  ABSL_ASSERT_OK(params_es521.status());
  absl::StatusOr<EcdsaParameters> want_p521_der_ecdsa_params =
      EcdsaParameters::Builder()
          .SetCurveType(EcdsaParameters::CurveType::kNistP521)
          .SetHashType(EcdsaParameters::HashType::kSha512)
          .SetSignatureEncoding(EcdsaParameters::SignatureEncoding::kDer)
          .SetVariant(EcdsaParameters::Variant::kNoPrefix)
          .Build();
  ABSL_ASSERT_OK(want_p521_der_ecdsa_params.status());
  absl::StatusOr<EcdsaParameters> want_p521_ieee_ecdsa_params =
      EcdsaParameters::Builder()
          .SetCurveType(EcdsaParameters::CurveType::kNistP521)
          .SetHashType(EcdsaParameters::HashType::kSha512)
          .SetSignatureEncoding(EcdsaParameters::SignatureEncoding::kIeeeP1363)
          .SetVariant(EcdsaParameters::Variant::kNoPrefix)
          .Build();
  ABSL_ASSERT_OK(want_p521_ieee_ecdsa_params.status());
  EXPECT_THAT(*params_es521, ElementsAre(*want_p521_ieee_ecdsa_params,
                                         *want_p521_der_ecdsa_params));

  EXPECT_THAT((*x509)->GetPemKeyParams(SigningAlgorithm::kPs256),
              StatusIs(absl::StatusCode::kInvalidArgument,
                       HasSubstr("Wrong key type")));
  EXPECT_THAT((*x509)->GetPemKeyParams(SigningAlgorithm::kEdDsa),
              StatusIs(absl::StatusCode::kInvalidArgument,
                       HasSubstr("Wrong key type")));
}

TEST(X509CertificateTest, GetPemKeyParamsForEdKey) {
  auto x509 = X509Certificate::Create(Base64Unescape(kDerEdBase64));
  ABSL_ASSERT_OK(x509.status());
  absl::StatusOr<std::vector<X509Certificate::TinkKeyParameters>> params_eddsa =
      (*x509)->GetPemKeyParams(SigningAlgorithm::kEdDsa);
  ABSL_ASSERT_OK(params_eddsa.status());
  absl::StatusOr<Ed25519Parameters> want_params =
      Ed25519Parameters::Create(Ed25519Parameters::Variant::kNoPrefix);
  ABSL_ASSERT_OK(want_params.status());
  EXPECT_THAT(*params_eddsa, ElementsAre(*want_params));

  EXPECT_THAT((*x509)->GetPemKeyParams(SigningAlgorithm::kPs256),
              StatusIs(absl::StatusCode::kInvalidArgument,
                       HasSubstr("Wrong key type")));
  EXPECT_THAT((*x509)->GetPemKeyParams(SigningAlgorithm::kEs256),
              StatusIs(absl::StatusCode::kInvalidArgument,
                       HasSubstr("Wrong key type")));
}
TEST(X509CertificateTest, VerifyEdSignedData) {
  auto x509 = X509Certificate::Create(Base64Unescape(kDerEdBase64));
  ABSL_ASSERT_OK(x509.status());
  EXPECT_THAT(
      (*x509)->VerifySignature(Base64Unescape(kEdSignatureBase64),
                               "this is a test", SigningAlgorithm::kEdDsa),
      IsOk());
}

TEST(X509CertificateTest, VerifySignatureWithRsaKey) {
  auto x509 = X509Certificate::Create(Base64Unescape(kDerRsaBase64));
  ABSL_ASSERT_OK(x509.status());
  // The actual signature and data don't matter for covering the lines in
  // MaybeConvertPssToRsa, as the key conversion happens before signature
  // verification. We expect a failure because the signature is invalid.
  EXPECT_THAT((*x509)->VerifySignature("fake_signature", "fake_data",
                                       SigningAlgorithm::kPs256),
              StatusIs(absl::StatusCode::kInvalidArgument,
                       HasSubstr("Tink verification failed")));
}

TEST(X509CertificateTest, GetStartTime) {
  auto x509 = X509Certificate::Create(Base64Unescape(kDerRsaBase64));
  ABSL_ASSERT_OK(x509.status());
  auto start_time = (*x509)->StartTime();
  ABSL_ASSERT_OK(start_time.status());
  EXPECT_EQ(absl::ToUnixSeconds(*start_time), 1704931200);
}

TEST(X509CertificateTest, GetEndTime) {
  auto x509 = X509Certificate::Create(Base64Unescape(kDerRsaBase64));
  ABSL_ASSERT_OK(x509.status());
  auto end_time = (*x509)->EndTime();
  ABSL_ASSERT_OK(end_time.status());
  EXPECT_EQ(absl::ToUnixSeconds(*end_time), 1736553599);
}

TEST(X509CertificateTest, GetSubjectIssuerNullName) {
  bssl::UniquePtr<X509> x509(X509_new());
  X509Certificate cert(std::move(x509));
  EXPECT_THAT(cert.GetSubject(), IsEmpty());
  EXPECT_THAT(cert.GetIssuer(), IsEmpty());
}

TEST(X509CertificateTest, GetSerialNumberHexRsa) {
  auto x509 = X509Certificate::Create(Base64Unescape(kDerRsaBase64));
  ABSL_ASSERT_OK(x509.status());
  auto serial_hex = (*x509)->GetSerialNumberHex();
  ABSL_ASSERT_OK(serial_hex.status());
  EXPECT_EQ(*serial_hex, "7ff2741fd1c6de43b5947a8e65709e9e");
}

TEST(X509CertificateTest, GetSerialNumberHexEcdsa) {
  auto x509 = X509Certificate::Create(Base64Unescape(kDerEcdsaBase64));
  ABSL_ASSERT_OK(x509.status());
  auto serial_hex = (*x509)->GetSerialNumberHex();
  ABSL_ASSERT_OK(serial_hex.status());
  EXPECT_EQ(*serial_hex, "7024e6247605f1d65f1b477551d4fafcb5ed91e6");
}

TEST(X509CertificateTest, GetSerialNumberHexEdDsa) {
  auto x509 = X509Certificate::Create(Base64Unescape(kDerEdBase64));
  ABSL_ASSERT_OK(x509.status());
  auto serial_hex = (*x509)->GetSerialNumberHex();
  ABSL_ASSERT_OK(serial_hex.status());
  EXPECT_EQ(*serial_hex, "667ad6b27de4f95c9931d3adda31f103867a40d2");
}

TEST(X509CertificateTest, GetAssuranceLevelNotFound) {
  auto x509 = X509Certificate::Create(Base64Unescape(kDerRsaBase64));
  ABSL_ASSERT_OK(x509.status());
  EXPECT_THAT((*x509)->GetAssuranceLevel(),
              StatusIs(absl::StatusCode::kNotFound));
}

TEST(X509CertificateTest, GetAssuranceLevelCorrectlyDecodesExtension) {
  constexpr absl::string_view kAssuranceLevelValueOid =
      "1.3.6.1.4.1.62558.3.20";
  constexpr absl::string_view kAssuranceLevelExtensionOid =
      "1.3.6.1.4.1.62558.3";
  bssl::UniquePtr<X509> x509(X509_new());
  ASSERT_NE(x509, nullptr);

  bssl::UniquePtr<ASN1_OBJECT> ext_oid(
      OBJ_txt2obj(kAssuranceLevelExtensionOid.data(), /*dont_search_names=*/1));
  ASSERT_NE(ext_oid, nullptr);

  bssl::UniquePtr<ASN1_OBJECT> val_oid(
      OBJ_txt2obj(kAssuranceLevelValueOid.data(), /*dont_search_names=*/1));
  ASSERT_NE(val_oid, nullptr);

  unsigned char* der_data = nullptr;
  int der_len = i2d_ASN1_OBJECT(val_oid.get(), &der_data);
  ASSERT_GT(der_len, 0);

  bssl::UniquePtr<ASN1_OCTET_STRING> octet_str(ASN1_OCTET_STRING_new());
  ASSERT_TRUE(ASN1_OCTET_STRING_set(octet_str.get(), der_data, der_len));
  OPENSSL_free(der_data);

  bssl::UniquePtr<X509_EXTENSION> ext(X509_EXTENSION_create_by_OBJ(
      nullptr, ext_oid.get(), /*crit=*/0, octet_str.get()));
  ASSERT_NE(ext, nullptr);
  ASSERT_TRUE(X509_add_ext(x509.get(), ext.get(), -1));

  X509Certificate cert(std::move(x509));
  EXPECT_THAT(cert.GetAssuranceLevel(), IsOkAndHolds(kAssuranceLevelValueOid));
}

TEST(X509CertificateTest, GetConformingProductIdNotFound) {
  auto x509 = X509Certificate::Create(Base64Unescape(kDerRsaBase64));
  ABSL_ASSERT_OK(x509.status());
  EXPECT_THAT((*x509)->GetConformingProductId(),
              StatusIs(absl::StatusCode::kNotFound));
}

TEST(X509CertificateTest, GetConformingProductIdCorrectlyDecodesExtension) {
  // Create a cert with the conforming product id extension.
  bssl::UniquePtr<X509> x509(X509_new());

  bssl::UniquePtr<ASN1_OBJECT> ext_oid(
      OBJ_txt2obj("1.3.6.1.4.1.62558.4", /*dont_search_names=*/1));
  ASSERT_THAT(ext_oid, NotNull());

  bssl::UniquePtr<ASN1_UTF8STRING> val_str(ASN1_UTF8STRING_new());
  constexpr absl::string_view kUuid = "c25c0e15-84dc-4cd7-95de-1d9ea4c7f0db";
  ASSERT_TRUE(ASN1_STRING_set(val_str.get(), kUuid.data(), kUuid.size()));

  unsigned char* der_data = nullptr;
  int der_len = i2d_ASN1_UTF8STRING(val_str.get(), &der_data);
  ASSERT_GT(der_len, 0);

  bssl::UniquePtr<ASN1_OCTET_STRING> octet_str(ASN1_OCTET_STRING_new());
  ASSERT_TRUE(ASN1_OCTET_STRING_set(octet_str.get(), der_data, der_len));
  OPENSSL_free(der_data);

  bssl::UniquePtr<X509_EXTENSION> ext(X509_EXTENSION_create_by_OBJ(
      nullptr, ext_oid.get(), /*crit=*/0, octet_str.get()));
  ASSERT_THAT(ext, NotNull());
  ASSERT_TRUE(X509_add_ext(x509.get(), ext.get(), -1));

  // Parse cert and extract the conforming product id.
  X509Certificate cert(std::move(x509));
  EXPECT_THAT(cert.GetConformingProductId(), IsOkAndHolds(kUuid));
}

TEST(X509CertificateTest, CertificateWithoutValidPublicKey) {
  bssl::UniquePtr<X509> x509(X509_new());
  ASSERT_NE(x509, nullptr);
  X509Certificate cert(std::move(x509));
  EXPECT_THAT(
      cert.VerifySignature("sig", "data", SigningAlgorithm::kPs256),
      StatusIs(absl::StatusCode::kInvalidArgument,
               HasSubstr("Certificate does not have a valid public key")));
  EXPECT_THAT(
      cert.GetPemKeyParams(SigningAlgorithm::kPs256),
      StatusIs(absl::StatusCode::kInvalidArgument,
               HasSubstr("Certificate does not have a valid public key")));
}

}  // namespace
}  // namespace credentio