cert/internal/trust_store_mac_unittest.cc

// Copyright 2017 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "net/cert/internal/trust_store_mac.h"

#include <algorithm>
#include <set>

#include "base/apple/scoped_cftyperef.h"
#include "base/base_paths.h"
#include "base/containers/to_vector.h"
#include "base/files/file_util.h"
#include "base/files/scoped_temp_dir.h"
#include "base/logging.h"
#include "base/path_service.h"
#include "base/process/launch.h"
#include "base/strings/strcat.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_split.h"
#include "base/synchronization/lock.h"
#include "base/test/metrics/histogram_tester.h"
#include "base/test/scoped_feature_list.h"
#include "crypto/mac_security_services_lock.h"
#include "crypto/sha2.h"
#include "net/base/features.h"
#include "net/cert/internal/test_helpers.h"
#include "net/cert/test_keychain_search_list_mac.h"
#include "net/cert/x509_certificate.h"
#include "net/cert/x509_util.h"
#include "net/cert/x509_util_apple.h"
#include "net/test/test_data_directory.h"
#include "testing/gmock/include/gmock/gmock.h"
#include "testing/gtest/include/gtest/gtest.h"
#include "third_party/boringssl/src/pki/cert_errors.h"
#include "third_party/boringssl/src/pki/parsed_certificate.h"
#include "third_party/boringssl/src/pki/pem.h"
#include "third_party/boringssl/src/pki/trust_store.h"

using ::testing::UnorderedElementsAreArray;

namespace net {

namespace {

// The PEM block header used for DER certificates
const char kCertificateHeader[] = "CERTIFICATE";

// Parses a PEM encoded certificate from |file_name| and stores in |result|.
::testing::AssertionResult ReadTestCert(
    const std::string& file_name,
    std::shared_ptr<const bssl::ParsedCertificate>* result) {
  std::string der;
  const PemBlockMapping mappings[] = {
      {kCertificateHeader, &der},
  };

  ::testing::AssertionResult r = ReadTestDataFromPemFile(
      "net/data/ssl/certificates/" + file_name, mappings);
  if (!r)
    return r;

  bssl::CertErrors errors;
  *result = bssl::ParsedCertificate::Create(x509_util::CreateCryptoBuffer(der),
                                            {}, &errors);
  if (!*result) {
    return ::testing::AssertionFailure()
           << "bssl::ParseCertificate::Create() failed:\n"
           << errors.ToDebugString();
  }
  return ::testing::AssertionSuccess();
}

// Returns the DER encodings of the ParsedCertificates in |list|.
std::vector<std::string> ParsedCertificateListAsDER(
    bssl::ParsedCertificateList list) {
  std::vector<std::string> result;
  for (const auto& it : list)
    result.push_back(it->der_cert().AsString());
  return result;
}

std::set<std::string> ParseFindCertificateOutputToDerCerts(std::string output) {
  std::set<std::string> certs;
  for (const std::string& hash_and_pem_partial : base::SplitStringUsingSubstr(
           output, "-----END CERTIFICATE-----", base::TRIM_WHITESPACE,
           base::SPLIT_WANT_NONEMPTY)) {
    // Re-add the PEM ending mark, since SplitStringUsingSubstr eats it.
    const std::string hash_and_pem =
        hash_and_pem_partial + "\n-----END CERTIFICATE-----\n";

    // Parse the PEM encoded text to DER bytes.
    bssl::PEMTokenizer pem_tokenizer(hash_and_pem, {kCertificateHeader});
    if (!pem_tokenizer.GetNext()) {
      ADD_FAILURE() << "!pem_tokenizer.GetNext()";
      continue;
    }
    std::string cert_der(pem_tokenizer.data());
    EXPECT_FALSE(pem_tokenizer.GetNext());
    certs.insert(cert_der);
  }
  return certs;
}

const char* TrustImplTypeToString(TrustStoreMac::TrustImplType t) {
  switch (t) {
    case TrustStoreMac::TrustImplType::kDomainCacheFullCerts:
      return "DomainCacheFullCerts";
    case TrustStoreMac::TrustImplType::kKeychainCacheFullCerts:
      return "KeychainCacheFullCerts";
    case TrustStoreMac::TrustImplType::kUnknown:
      return "Unknown";
  }
}

}  // namespace

class TrustStoreMacImplTest
    : public testing::TestWithParam<TrustStoreMac::TrustImplType> {
 public:
  TrustStoreMac::TrustImplType GetImplParam() const { return GetParam(); }

  bssl::CertificateTrust ExpectedTrustForAnchor() const {
    return bssl::CertificateTrust::ForTrustAnchorOrLeaf()
        .WithEnforceAnchorExpiry()
        .WithEnforceAnchorConstraints()
        .WithRequireAnchorBasicConstraints();
  }
};

// Much of the Keychain API was marked deprecated as of the macOS 13 SDK.
// Removal of its use is tracked in https://crbug.com/1348251 but deprecation
// warnings are disabled in the meanwhile.
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-declarations"

// Test the trust store using known test certificates in a keychain.  Tests
// that issuer searching returns the expected certificates, and that none of
// the certificates are trusted.
TEST_P(TrustStoreMacImplTest, MultiRootNotTrusted) {
  std::unique_ptr<TestKeychainSearchList> test_keychain_search_list(
      TestKeychainSearchList::Create());
  ASSERT_TRUE(test_keychain_search_list);
  base::FilePath keychain_path(
      GetTestCertsDirectory().AppendASCII("multi-root.keychain"));
  // SecKeychainOpen does not fail if the file doesn't exist, so assert it here
  // for easier debugging.
  ASSERT_TRUE(base::PathExists(keychain_path));
  base::apple::ScopedCFTypeRef<SecKeychainRef> keychain;
  OSStatus status = SecKeychainOpen(keychain_path.MaybeAsASCII().c_str(),
                                    keychain.InitializeInto());
  ASSERT_EQ(errSecSuccess, status);
  ASSERT_TRUE(keychain);
  test_keychain_search_list->AddKeychain(keychain.get());

#pragma clang diagnostic pop

  const TrustStoreMac::TrustImplType trust_impl = GetImplParam();
  TrustStoreMac trust_store(kSecPolicyAppleSSL, trust_impl);

  std::map<std::vector<uint8_t>, bssl::CertificateTrust> user_added_certs;
  for (const auto& cert_with_trust : trust_store.GetAllUserAddedCerts()) {
    user_added_certs[cert_with_trust.cert_bytes] = cert_with_trust.trust;
  }

  std::shared_ptr<const bssl::ParsedCertificate> a_by_b, b_by_c, b_by_f, c_by_d,
      c_by_e, f_by_e, d_by_d, e_by_e;
  ASSERT_TRUE(ReadTestCert("multi-root-A-by-B.pem", &a_by_b));
  ASSERT_TRUE(ReadTestCert("multi-root-B-by-C.pem", &b_by_c));
  ASSERT_TRUE(ReadTestCert("multi-root-B-by-F.pem", &b_by_f));
  ASSERT_TRUE(ReadTestCert("multi-root-C-by-D.pem", &c_by_d));
  ASSERT_TRUE(ReadTestCert("multi-root-C-by-E.pem", &c_by_e));
  ASSERT_TRUE(ReadTestCert("multi-root-F-by-E.pem", &f_by_e));
  ASSERT_TRUE(ReadTestCert("multi-root-D-by-D.pem", &d_by_d));
  ASSERT_TRUE(ReadTestCert("multi-root-E-by-E.pem", &e_by_e));

  // Test that the untrusted keychain certs would be found during issuer
  // searching.
  {
    bssl::ParsedCertificateList found_issuers;
    trust_store.SyncGetIssuersOf(a_by_b.get(), &found_issuers);
    EXPECT_THAT(ParsedCertificateListAsDER(found_issuers),
                UnorderedElementsAreArray(
                    ParsedCertificateListAsDER({b_by_c, b_by_f})));
  }

  {
    bssl::ParsedCertificateList found_issuers;
    trust_store.SyncGetIssuersOf(b_by_c.get(), &found_issuers);
    EXPECT_THAT(ParsedCertificateListAsDER(found_issuers),
                UnorderedElementsAreArray(
                    ParsedCertificateListAsDER({c_by_d, c_by_e})));
  }

  {
    bssl::ParsedCertificateList found_issuers;
    trust_store.SyncGetIssuersOf(b_by_f.get(), &found_issuers);
    EXPECT_THAT(
        ParsedCertificateListAsDER(found_issuers),
        UnorderedElementsAreArray(ParsedCertificateListAsDER({f_by_e})));
  }

  {
    bssl::ParsedCertificateList found_issuers;
    trust_store.SyncGetIssuersOf(c_by_d.get(), &found_issuers);
    EXPECT_THAT(
        ParsedCertificateListAsDER(found_issuers),
        UnorderedElementsAreArray(ParsedCertificateListAsDER({d_by_d})));
  }

  {
    bssl::ParsedCertificateList found_issuers;
    trust_store.SyncGetIssuersOf(f_by_e.get(), &found_issuers);
    EXPECT_THAT(
        ParsedCertificateListAsDER(found_issuers),
        UnorderedElementsAreArray(ParsedCertificateListAsDER({e_by_e})));
  }

  // Verify that none of the added certificates are considered trusted (since
  // the test certs in the keychain aren't trusted, unless someone manually
  // added and trusted the test certs on the machine the test is being run on).
  for (const auto& cert :
       {a_by_b, b_by_c, b_by_f, c_by_d, c_by_e, f_by_e, d_by_d, e_by_e}) {
    bssl::CertificateTrust trust = trust_store.GetTrust(cert.get());
    EXPECT_EQ(bssl::CertificateTrust::ForUnspecified().ToDebugString(),
              trust.ToDebugString());

    std::vector<uint8_t> cert_bytes = base::ToVector(cert->der_cert());
    if (cert == a_by_b) {
      // If the certificate is the leaf, it should not be present in the
      // GetAllUserAddedCerts results, which only returns trusted/distrusted
      // certs or intermediates.
      EXPECT_FALSE(user_added_certs.contains(cert_bytes));
    } else {
      // Otherwise it should be present in the list and be untrusted.
      EXPECT_TRUE(user_added_certs.contains(cert_bytes));
      EXPECT_TRUE(user_added_certs[cert_bytes].HasUnspecifiedTrust());
    }
  }
}

// Test against all the certificates in the default keychains. Confirms that
// the computed trust value matches that of SecTrustEvaluateWithError.
TEST_P(TrustStoreMacImplTest, SystemCerts) {
  // Get the list of all certificates in the user & system keychains.
  // This may include both trusted and untrusted certificates.
  //
  // The output contains zero or more repetitions of:
  // "SHA-1 hash: <hash>\n<PEM encoded cert>\n"
  // Starting with macOS 10.15, it includes both SHA-256 and SHA-1 hashes:
  // "SHA-256 hash: <hash>\nSHA-1 hash: <hash>\n<PEM encoded cert>\n"
  std::string find_certificate_default_search_list_output;
  ASSERT_TRUE(
      base::GetAppOutput({"security", "find-certificate", "-a", "-p", "-Z"},
                         &find_certificate_default_search_list_output));
  // Get the list of all certificates in the system roots keychain.
  // (Same details as above.)
  std::string find_certificate_system_roots_output;
  ASSERT_TRUE(base::GetAppOutput(
      {"security", "find-certificate", "-a", "-p", "-Z",
       "/System/Library/Keychains/SystemRootCertificates.keychain"},
      &find_certificate_system_roots_output));

  std::set<std::string> find_certificate_default_search_list_certs =
      ParseFindCertificateOutputToDerCerts(
          find_certificate_default_search_list_output);
  std::set<std::string> find_certificate_system_roots_certs =
      ParseFindCertificateOutputToDerCerts(
          find_certificate_system_roots_output);

  const TrustStoreMac::TrustImplType trust_impl = GetImplParam();

  base::HistogramTester histogram_tester;
  TrustStoreMac trust_store(kSecPolicyAppleX509Basic, trust_impl);

  std::map<std::string, bssl::CertificateTrust> user_added_certs;
  for (const auto& cert_with_trust : trust_store.GetAllUserAddedCerts()) {
    user_added_certs[std::string(base::as_string_view(
        cert_with_trust.cert_bytes))] = cert_with_trust.trust;
  }

  base::apple::ScopedCFTypeRef<SecPolicyRef> sec_policy(
      SecPolicyCreateBasicX509());
  ASSERT_TRUE(sec_policy);
  std::vector<std::string> all_certs;
  std::set_union(find_certificate_default_search_list_certs.begin(),
                 find_certificate_default_search_list_certs.end(),
                 find_certificate_system_roots_certs.begin(),
                 find_certificate_system_roots_certs.end(),
                 std::back_inserter(all_certs));
  for (const std::string& cert_der : all_certs) {
    std::string hash = crypto::SHA256HashString(cert_der);
    std::string hash_text = base::HexEncode(hash);
    SCOPED_TRACE(hash_text);

    bssl::CertErrors errors;
    // Note: don't actually need to make a bssl::ParsedCertificate here, just
    // need the DER bytes. But parsing it here ensures the test can skip any
    // certs that won't be returned due to parsing failures inside
    // TrustStoreMac. The parsing options set here need to match the ones used
    // in trust_store_mac.cc.
    bssl::ParseCertificateOptions options;
    // For https://crt.sh/?q=D3EEFBCBBCF49867838626E23BB59CA01E305DB7:
    options.allow_invalid_serial_numbers = true;
    std::shared_ptr<const bssl::ParsedCertificate> cert =
        bssl::ParsedCertificate::Create(x509_util::CreateCryptoBuffer(cert_der),
                                        options, &errors);
    if (!cert) {
      LOG(WARNING) << "bssl::ParseCertificate::Create " << hash_text
                   << " failed:\n"
                   << errors.ToDebugString();
      continue;
    }

    base::apple::ScopedCFTypeRef<SecCertificateRef> cert_handle(
        x509_util::CreateSecCertificateFromBytes(cert->der_cert()));
    if (!cert_handle) {
      ADD_FAILURE() << "CreateCertBufferFromBytes " << hash_text;
      continue;
    }

    // Check if this cert is considered a trust anchor by TrustStoreMac.
    bssl::CertificateTrust cert_trust = trust_store.GetTrust(cert.get());
    bool is_trusted = cert_trust.IsTrustAnchor() || cert_trust.IsTrustLeaf();
    if (is_trusted) {
      EXPECT_EQ(ExpectedTrustForAnchor().ToDebugString(),
                cert_trust.ToDebugString());
      // If the cert is trusted, it should be in the GetAllUserAddedCerts
      // result with the same trust value. (If it's not trusted, it may or may
      // not be present so we can't test that here, MultiRootNotTrusted tests
      // that.)
      EXPECT_TRUE(user_added_certs.contains(cert_der));
      EXPECT_EQ(user_added_certs[cert_der].ToDebugString(),
                cert_trust.ToDebugString());
    }

    // Check if this cert is considered a trust anchor by the OS.
    base::apple::ScopedCFTypeRef<SecTrustRef> trust;
    {
      base::AutoLock lock(crypto::GetMacSecurityServicesLock());
      ASSERT_EQ(noErr, SecTrustCreateWithCertificates(cert_handle.get(),
                                                      sec_policy.get(),
                                                      trust.InitializeInto()));
      ASSERT_EQ(noErr, SecTrustSetOptions(trust.get(),
                                          kSecTrustOptionLeafIsCA |
                                              kSecTrustOptionAllowExpired |
                                              kSecTrustOptionAllowExpiredRoot));

      if (find_certificate_default_search_list_certs.count(cert_der) &&
          find_certificate_system_roots_certs.count(cert_der)) {
        // If the same certificate is present in both the System and User/Admin
        // domains, and TrustStoreMac is only using trust settings from
        // User/Admin, then it's not possible for this test to know whether the
        // result from SecTrustEvaluate should match the TrustStoreMac result.
        // Just ignore such certificates.
      } else if (!find_certificate_default_search_list_certs.count(cert_der)) {
        // Cert is only in the system domain. It should be untrusted.
        EXPECT_FALSE(is_trusted);
        // It should not be in the GetAllUserAddedCerts results either.
        EXPECT_FALSE(user_added_certs.contains(cert_der));
      } else {
        bool trusted = SecTrustEvaluateWithError(trust.get(), nullptr);
        bool expected_trust_anchor =
            trusted && (SecTrustGetCertificateCount(trust.get()) == 1);
        EXPECT_EQ(expected_trust_anchor, is_trusted);
      }
    }

    // Call GetTrust again on the same cert. This should exercise the code
    // that checks the trust value for a cert which has already been cached.
    bssl::CertificateTrust cert_trust2 = trust_store.GetTrust(cert.get());
    EXPECT_EQ(cert_trust.ToDebugString(), cert_trust2.ToDebugString());
  }

  // Since this is testing the actual platform certs and trust settings, we
  // don't know what values the histograms should be, so just verify that the
  // histogram is recorded (or not) depending on the requested trust impl.

  {
    // Histograms only logged by DomainCacheFullCerts impl:
    const int expected_count =
        (trust_impl == TrustStoreMac::TrustImplType::kDomainCacheFullCerts) ? 1
                                                                            : 0;
    histogram_tester.ExpectTotalCount(
        "Net.CertVerifier.MacTrustDomainCertCount.User", expected_count);
    histogram_tester.ExpectTotalCount(
        "Net.CertVerifier.MacTrustDomainCertCount.Admin", expected_count);
    histogram_tester.ExpectTotalCount(
        "Net.CertVerifier.MacTrustDomainCacheInitTime", expected_count);
    histogram_tester.ExpectTotalCount(
        "Net.CertVerifier.MacKeychainCerts.IntermediateCacheInitTime",
        expected_count);
  }

  {
    // Histograms only logged by KeychainCacheFullCerts impl:
    const int expected_count =
        (trust_impl == TrustStoreMac::TrustImplType::kKeychainCacheFullCerts)
            ? 1
            : 0;
    histogram_tester.ExpectTotalCount(
        "Net.CertVerifier.MacKeychainCerts.TrustCount", expected_count);
  }

  {
    // Histograms logged by both DomainCacheFullCerts and KeychainCacheFullCerts
    // impls:
    const int expected_count =
        (trust_impl == TrustStoreMac::TrustImplType::kDomainCacheFullCerts ||
         trust_impl == TrustStoreMac::TrustImplType::kKeychainCacheFullCerts)
            ? 1
            : 0;
    histogram_tester.ExpectTotalCount(
        "Net.CertVerifier.MacKeychainCerts.IntermediateCount", expected_count);
    histogram_tester.ExpectTotalCount(
        "Net.CertVerifier.MacKeychainCerts.TotalCount", expected_count);
    histogram_tester.ExpectTotalCount(
        "Net.CertVerifier.MacTrustImplCacheInitTime", expected_count);
  }
}

INSTANTIATE_TEST_SUITE_P(
    Impl,
    TrustStoreMacImplTest,
    testing::Values(TrustStoreMac::TrustImplType::kDomainCacheFullCerts,
                    TrustStoreMac::TrustImplType::kKeychainCacheFullCerts),
    [](const testing::TestParamInfo<TrustStoreMacImplTest::ParamType>& info) {
      return TrustImplTypeToString(info.param);
    });

}  // namespace net