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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "CertVerifier.h"
#include <stdint.h>
#include "CTDiversityPolicy.h"
#include "CTKnownLogs.h"
#include "CTLogVerifier.h"
#include "ExtendedValidation.h"
#include "MultiLogCTVerifier.h"
#include "NSSCertDBTrustDomain.h"
#include "NSSErrorsService.h"
#include "cert.h"
#include "mozilla/Assertions.h"
#include "mozilla/Casting.h"
#include "mozilla/IntegerPrintfMacros.h"
#include "nsNSSComponent.h"
#include "nsPromiseFlatString.h"
#include "nsServiceManagerUtils.h"
#include "pk11pub.h"
#include "mozpkix/pkix.h"
#include "mozpkix/pkixnss.h"
#include "secmod.h"
using namespace mozilla::ct;
using namespace mozilla::pkix;
using namespace mozilla::psm;
mozilla::LazyLogModule gCertVerifierLog("certverifier");
// Returns the certificate validity period in calendar months (rounded down).
// "extern" to allow unit tests in CTPolicyEnforcerTest.cpp.
extern mozilla::pkix::Result GetCertLifetimeInFullMonths(PRTime certNotBefore,
PRTime certNotAfter,
size_t& months) {
if (certNotBefore >= certNotAfter) {
MOZ_ASSERT_UNREACHABLE("Expected notBefore < notAfter");
return mozilla::pkix::Result::FATAL_ERROR_INVALID_ARGS;
}
PRExplodedTime explodedNotBefore;
PRExplodedTime explodedNotAfter;
PR_ExplodeTime(certNotBefore, PR_LocalTimeParameters, &explodedNotBefore);
PR_ExplodeTime(certNotAfter, PR_LocalTimeParameters, &explodedNotAfter);
PRInt32 signedMonths =
(explodedNotAfter.tm_year - explodedNotBefore.tm_year) * 12 +
(explodedNotAfter.tm_month - explodedNotBefore.tm_month);
if (explodedNotAfter.tm_mday < explodedNotBefore.tm_mday) {
--signedMonths;
}
// Can't use `mozilla::AssertedCast<size_t>(signedMonths)` below
// since it currently generates a warning on Win x64 debug.
if (signedMonths < 0) {
MOZ_ASSERT_UNREACHABLE("Expected explodedNotBefore < explodedNotAfter");
return mozilla::pkix::Result::FATAL_ERROR_LIBRARY_FAILURE;
}
months = static_cast<size_t>(signedMonths);
return Success;
}
namespace mozilla {
namespace psm {
const CertVerifier::Flags CertVerifier::FLAG_LOCAL_ONLY = 1;
const CertVerifier::Flags CertVerifier::FLAG_MUST_BE_EV = 2;
const CertVerifier::Flags CertVerifier::FLAG_TLS_IGNORE_STATUS_REQUEST = 4;
static const unsigned int MIN_RSA_BITS = 2048;
static const unsigned int MIN_RSA_BITS_WEAK = 1024;
void CertificateTransparencyInfo::Reset() {
enabled = false;
verifyResult.Reset();
policyCompliance = CTPolicyCompliance::Unknown;
}
CertVerifier::CertVerifier(OcspDownloadConfig odc, OcspStrictConfig osc,
mozilla::TimeDuration ocspTimeoutSoft,
mozilla::TimeDuration ocspTimeoutHard,
uint32_t certShortLifetimeInDays,
PinningMode pinningMode, SHA1Mode sha1Mode,
BRNameMatchingPolicy::Mode nameMatchingMode,
NetscapeStepUpPolicy netscapeStepUpPolicy,
CertificateTransparencyMode ctMode,
DistrustedCAPolicy distrustedCAPolicy,
CRLiteMode crliteMode,
uint64_t crliteCTMergeDelaySeconds,
const Vector<EnterpriseCert>& thirdPartyCerts)
: mOCSPDownloadConfig(odc),
mOCSPStrict(osc == ocspStrict),
mOCSPTimeoutSoft(ocspTimeoutSoft),
mOCSPTimeoutHard(ocspTimeoutHard),
mCertShortLifetimeInDays(certShortLifetimeInDays),
mPinningMode(pinningMode),
mSHA1Mode(sha1Mode),
mNameMatchingMode(nameMatchingMode),
mNetscapeStepUpPolicy(netscapeStepUpPolicy),
mCTMode(ctMode),
mDistrustedCAPolicy(distrustedCAPolicy),
mCRLiteMode(crliteMode),
mCRLiteCTMergeDelaySeconds(crliteCTMergeDelaySeconds) {
LoadKnownCTLogs();
for (const auto& root : thirdPartyCerts) {
EnterpriseCert rootCopy;
// Best-effort. If we run out of memory, users might see untrusted issuer
// errors, but the browser will probably crash before then.
if (NS_SUCCEEDED(rootCopy.Init(root))) {
Unused << mThirdPartyCerts.append(std::move(rootCopy));
}
}
for (const auto& root : mThirdPartyCerts) {
Input input;
if (root.GetInput(input) == Success) {
// mThirdPartyCerts consists of roots and intermediates.
if (root.GetIsRoot()) {
// Best effort again.
Unused << mThirdPartyRootInputs.append(input);
} else {
Unused << mThirdPartyIntermediateInputs.append(input);
}
}
}
}
CertVerifier::~CertVerifier() = default;
Result IsCertChainRootBuiltInRoot(const UniqueCERTCertList& chain,
bool& result) {
if (!chain || CERT_LIST_EMPTY(chain)) {
return Result::FATAL_ERROR_LIBRARY_FAILURE;
}
CERTCertListNode* rootNode = CERT_LIST_TAIL(chain);
if (!rootNode) {
return Result::FATAL_ERROR_LIBRARY_FAILURE;
}
CERTCertificate* root = rootNode->cert;
if (!root) {
return Result::FATAL_ERROR_LIBRARY_FAILURE;
}
return IsCertBuiltInRoot(root, result);
}
Result IsDelegatedCredentialAcceptable(const DelegatedCredentialInfo& dcInfo,
SECOidTag evOidPolicyTag) {
bool isEcdsa = dcInfo.scheme == ssl_sig_ecdsa_secp256r1_sha256 ||
dcInfo.scheme == ssl_sig_ecdsa_secp384r1_sha384 ||
dcInfo.scheme == ssl_sig_ecdsa_secp521r1_sha512;
// Firefox currently does not advertise any RSA schemes for use
// with Delegated Credentials. As a secondary (on top of NSS)
// check, disallow any RSA SPKI here. When ssl_sig_rsa_pss_pss_*
// schemes are supported, check the modulus size and allow RSA here.
if (!isEcdsa) {
return Result::ERROR_INVALID_KEY;
}
return Result::Success;
}
// The term "builtin root" traditionally refers to a root CA certificate that
// has been added to the NSS trust store, because it has been approved
// for inclusion according to the Mozilla CA policy, and might be accepted
// by Mozilla applications as an issuer for certificates seen on the public web.
Result IsCertBuiltInRoot(CERTCertificate* cert, bool& result) {
if (NS_FAILED(BlockUntilLoadableCertsLoaded())) {
return Result::FATAL_ERROR_LIBRARY_FAILURE;
}
result = false;
#ifdef DEBUG
nsCOMPtr<nsINSSComponent> component(do_GetService(PSM_COMPONENT_CONTRACTID));
if (!component) {
return Result::FATAL_ERROR_LIBRARY_FAILURE;
}
nsresult rv = component->IsCertTestBuiltInRoot(cert, &result);
if (NS_FAILED(rv)) {
return Result::FATAL_ERROR_LIBRARY_FAILURE;
}
if (result) {
return Success;
}
#endif // DEBUG
AutoSECMODListReadLock lock;
for (SECMODModuleList* list = SECMOD_GetDefaultModuleList(); list;
list = list->next) {
for (int i = 0; i < list->module->slotCount; i++) {
PK11SlotInfo* slot = list->module->slots[i];
// We're searching for the "builtin root module", which is a module that
// contains an object with a CKA_CLASS of CKO_NETSCAPE_BUILTIN_ROOT_LIST.
// We use PK11_HasRootCerts() to identify a module with that property.
// In the past, we exclusively used the PKCS#11 module named nssckbi,
// which is provided by the NSS library.
// Nowadays, some distributions use a replacement module, which contains
// the builtin roots, but which also contains additional CA certificates,
// such as CAs trusted in a local deployment.
// We want to be able to distinguish between these two categories,
// because a CA, which may issue certificates for the public web,
// is expected to comply with additional requirements.
// If the certificate has attribute CKA_NSS_MOZILLA_CA_POLICY set to true,
// then we treat it as a "builtin root".
if (PK11_IsPresent(slot) && PK11_HasRootCerts(slot)) {
CK_OBJECT_HANDLE handle = PK11_FindCertInSlot(slot, cert, nullptr);
if (handle != CK_INVALID_HANDLE &&
PK11_HasAttributeSet(slot, handle, CKA_NSS_MOZILLA_CA_POLICY,
false)) {
// Attribute was found, and is set to true
result = true;
break;
}
}
}
}
return Success;
}
static Result BuildCertChainForOneKeyUsage(
NSSCertDBTrustDomain& trustDomain, Input certDER, Time time, KeyUsage ku1,
KeyUsage ku2, KeyUsage ku3, KeyPurposeId eku,
const CertPolicyId& requiredPolicy, const Input* stapledOCSPResponse,
/*optional out*/ CertVerifier::OCSPStaplingStatus* ocspStaplingStatus) {
trustDomain.ResetAccumulatedState();
Result rv =
BuildCertChain(trustDomain, certDER, time, EndEntityOrCA::MustBeEndEntity,
ku1, eku, requiredPolicy, stapledOCSPResponse);
if (rv == Result::ERROR_INADEQUATE_KEY_USAGE) {
trustDomain.ResetAccumulatedState();
rv = BuildCertChain(trustDomain, certDER, time,
EndEntityOrCA::MustBeEndEntity, ku2, eku,
requiredPolicy, stapledOCSPResponse);
if (rv == Result::ERROR_INADEQUATE_KEY_USAGE) {
trustDomain.ResetAccumulatedState();
rv = BuildCertChain(trustDomain, certDER, time,
EndEntityOrCA::MustBeEndEntity, ku3, eku,
requiredPolicy, stapledOCSPResponse);
if (rv != Success) {
rv = Result::ERROR_INADEQUATE_KEY_USAGE;
}
}
}
if (ocspStaplingStatus) {
*ocspStaplingStatus = trustDomain.GetOCSPStaplingStatus();
}
return rv;
}
void CertVerifier::LoadKnownCTLogs() {
if (mCTMode == CertificateTransparencyMode::Disabled) {
return;
}
mCTVerifier = MakeUnique<MultiLogCTVerifier>();
for (const CTLogInfo& log : kCTLogList) {
Input publicKey;
Result rv = publicKey.Init(
BitwiseCast<const uint8_t*, const char*>(log.key), log.keyLength);
if (rv != Success) {
MOZ_ASSERT_UNREACHABLE("Failed reading a log key for a known CT Log");
continue;
}
CTLogVerifier logVerifier;
const CTLogOperatorInfo& logOperator =
kCTLogOperatorList[log.operatorIndex];
rv = logVerifier.Init(publicKey, logOperator.id, log.status,
log.disqualificationTime);
if (rv != Success) {
MOZ_ASSERT_UNREACHABLE("Failed initializing a known CT Log");
continue;
}
mCTVerifier->AddLog(std::move(logVerifier));
}
// TBD: Initialize mCTDiversityPolicy with the CA dependency map
// of the known CT logs operators.
mCTDiversityPolicy = MakeUnique<CTDiversityPolicy>();
}
Result CertVerifier::VerifyCertificateTransparencyPolicy(
NSSCertDBTrustDomain& trustDomain, const UniqueCERTCertList& builtChain,
Input sctsFromTLS, Time time,
/*optional out*/ CertificateTransparencyInfo* ctInfo) {
if (ctInfo) {
ctInfo->Reset();
}
if (mCTMode == CertificateTransparencyMode::Disabled) {
return Success;
}
if (ctInfo) {
ctInfo->enabled = true;
}
if (!builtChain || CERT_LIST_EMPTY(builtChain)) {
return Result::FATAL_ERROR_INVALID_ARGS;
}
Input embeddedSCTs = trustDomain.GetSCTListFromCertificate();
if (embeddedSCTs.GetLength() > 0) {
MOZ_LOG(gCertVerifierLog, LogLevel::Debug,
("Got embedded SCT data of length %zu\n",
static_cast<size_t>(embeddedSCTs.GetLength())));
}
Input sctsFromOCSP = trustDomain.GetSCTListFromOCSPStapling();
if (sctsFromOCSP.GetLength() > 0) {
MOZ_LOG(gCertVerifierLog, LogLevel::Debug,
("Got OCSP SCT data of length %zu\n",
static_cast<size_t>(sctsFromOCSP.GetLength())));
}
if (sctsFromTLS.GetLength() > 0) {
MOZ_LOG(gCertVerifierLog, LogLevel::Debug,
("Got TLS SCT data of length %zu\n",
static_cast<size_t>(sctsFromTLS.GetLength())));
}
CERTCertListNode* endEntityNode = CERT_LIST_HEAD(builtChain);
if (!endEntityNode || CERT_LIST_END(endEntityNode, builtChain)) {
return Result::FATAL_ERROR_INVALID_ARGS;
}
CERTCertListNode* issuerNode = CERT_LIST_NEXT(endEntityNode);
if (!issuerNode || CERT_LIST_END(issuerNode, builtChain)) {
// Issuer certificate is required for SCT verification.
// If we've arrived here, we probably have a "trust chain" with only one
// certificate (i.e. a self-signed end-entity that has been set as a trust
// anchor either by a third party modifying our trust DB or via the
// enterprise roots feature). If this is the case, certificate transparency
// information will probably not be present, and it certainly won't verify
// correctly. To simplify things, we return an empty CTVerifyResult and a
// "not enough SCTs" CTPolicyCompliance result.
if (ctInfo) {
CTVerifyResult emptyResult;
ctInfo->verifyResult = std::move(emptyResult);
ctInfo->policyCompliance = CTPolicyCompliance::NotEnoughScts;
}
return Success;
}
CERTCertificate* endEntity = endEntityNode->cert;
CERTCertificate* issuer = issuerNode->cert;
if (!endEntity || !issuer) {
return Result::FATAL_ERROR_INVALID_ARGS;
}
if (endEntity->subjectName) {
MOZ_LOG(gCertVerifierLog, LogLevel::Debug,
("Verifying CT Policy compliance of subject %s\n",
endEntity->subjectName));
}
Input endEntityDER;
Result rv =
endEntityDER.Init(endEntity->derCert.data, endEntity->derCert.len);
if (rv != Success) {
return rv;
}
Input issuerPublicKeyDER;
rv = issuerPublicKeyDER.Init(issuer->derPublicKey.data,
issuer->derPublicKey.len);
if (rv != Success) {
return rv;
}
CTVerifyResult result;
rv = mCTVerifier->Verify(endEntityDER, issuerPublicKeyDER, embeddedSCTs,
sctsFromOCSP, sctsFromTLS, time, result);
if (rv != Success) {
MOZ_LOG(gCertVerifierLog, LogLevel::Debug,
("SCT verification failed with fatal error %" PRId32 "\n",
static_cast<uint32_t>(rv)));
return rv;
}
if (MOZ_LOG_TEST(gCertVerifierLog, LogLevel::Debug)) {
size_t validCount = 0;
size_t unknownLogCount = 0;
size_t disqualifiedLogCount = 0;
size_t invalidSignatureCount = 0;
size_t invalidTimestampCount = 0;
for (const VerifiedSCT& verifiedSct : result.verifiedScts) {
switch (verifiedSct.status) {
case VerifiedSCT::Status::Valid:
validCount++;
break;
case VerifiedSCT::Status::ValidFromDisqualifiedLog:
disqualifiedLogCount++;
break;
case VerifiedSCT::Status::UnknownLog:
unknownLogCount++;
break;
case VerifiedSCT::Status::InvalidSignature:
invalidSignatureCount++;
break;
case VerifiedSCT::Status::InvalidTimestamp:
invalidTimestampCount++;
break;
case VerifiedSCT::Status::None:
default:
MOZ_ASSERT_UNREACHABLE("Unexpected SCT verification status");
}
}
MOZ_LOG(
gCertVerifierLog, LogLevel::Debug,
("SCT verification result: "
"valid=%zu unknownLog=%zu disqualifiedLog=%zu "
"invalidSignature=%zu invalidTimestamp=%zu "
"decodingErrors=%zu\n",
validCount, unknownLogCount, disqualifiedLogCount,
invalidSignatureCount, invalidTimestampCount, result.decodingErrors));
}
PRTime notBefore;
PRTime notAfter;
if (CERT_GetCertTimes(endEntity, &notBefore, &notAfter) != SECSuccess) {
return Result::FATAL_ERROR_LIBRARY_FAILURE;
}
size_t lifetimeInMonths;
rv = GetCertLifetimeInFullMonths(notBefore, notAfter, lifetimeInMonths);
if (rv != Success) {
return rv;
}
CTLogOperatorList allOperators;
GetCTLogOperatorsFromVerifiedSCTList(result.verifiedScts, allOperators);
CTLogOperatorList dependentOperators;
rv = mCTDiversityPolicy->GetDependentOperators(builtChain.get(), allOperators,
dependentOperators);
if (rv != Success) {
return rv;
}
CTPolicyEnforcer ctPolicyEnforcer;
CTPolicyCompliance ctPolicyCompliance;
ctPolicyEnforcer.CheckCompliance(result.verifiedScts, lifetimeInMonths,
dependentOperators, ctPolicyCompliance);
if (ctInfo) {
ctInfo->verifyResult = std::move(result);
ctInfo->policyCompliance = ctPolicyCompliance;
}
return Success;
}
bool CertVerifier::SHA1ModeMoreRestrictiveThanGivenMode(SHA1Mode mode) {
switch (mSHA1Mode) {
case SHA1Mode::Forbidden:
return mode != SHA1Mode::Forbidden;
case SHA1Mode::ImportedRoot:
return mode != SHA1Mode::Forbidden && mode != SHA1Mode::ImportedRoot;
case SHA1Mode::ImportedRootOrBefore2016:
return mode == SHA1Mode::Allowed;
case SHA1Mode::Allowed:
return false;
// MSVC warns unless we explicitly handle this now-unused option.
case SHA1Mode::UsedToBeBefore2016ButNowIsForbidden:
default:
MOZ_ASSERT(false, "unexpected SHA1Mode type");
return true;
}
}
Result CertVerifier::VerifyCert(
CERTCertificate* cert, SECCertificateUsage usage, Time time, void* pinArg,
const char* hostname,
/*out*/ UniqueCERTCertList& builtChain,
/*optional*/ const Flags flags,
/*optional*/ const Maybe<nsTArray<nsTArray<uint8_t>>>& extraCertificates,
/*optional*/ const Maybe<nsTArray<uint8_t>>& stapledOCSPResponseArg,
/*optional*/ const Maybe<nsTArray<uint8_t>>& sctsFromTLS,
/*optional*/ const OriginAttributes& originAttributes,
/*optional out*/ SECOidTag* evOidPolicy,
/*optional out*/ OCSPStaplingStatus* ocspStaplingStatus,
/*optional out*/ KeySizeStatus* keySizeStatus,
/*optional out*/ SHA1ModeResult* sha1ModeResult,
/*optional out*/ PinningTelemetryInfo* pinningTelemetryInfo,
/*optional out*/ CertificateTransparencyInfo* ctInfo,
/*optional out*/ CRLiteTelemetryInfo* crliteInfo) {
MOZ_LOG(gCertVerifierLog, LogLevel::Debug, ("Top of VerifyCert\n"));
MOZ_ASSERT(cert);
MOZ_ASSERT(usage == certificateUsageSSLServer || !(flags & FLAG_MUST_BE_EV));
MOZ_ASSERT(usage == certificateUsageSSLServer || !keySizeStatus);
MOZ_ASSERT(usage == certificateUsageSSLServer || !sha1ModeResult);
if (NS_FAILED(BlockUntilLoadableCertsLoaded())) {
return Result::FATAL_ERROR_LIBRARY_FAILURE;
}
if (NS_FAILED(CheckForSmartCardChanges())) {
return Result::FATAL_ERROR_LIBRARY_FAILURE;
}
if (evOidPolicy) {
*evOidPolicy = SEC_OID_UNKNOWN;
}
if (ocspStaplingStatus) {
if (usage != certificateUsageSSLServer) {
return Result::FATAL_ERROR_INVALID_ARGS;
}
*ocspStaplingStatus = OCSP_STAPLING_NEVER_CHECKED;
}
if (keySizeStatus) {
if (usage != certificateUsageSSLServer) {
return Result::FATAL_ERROR_INVALID_ARGS;
}
*keySizeStatus = KeySizeStatus::NeverChecked;
}
if (sha1ModeResult) {
if (usage != certificateUsageSSLServer) {
return Result::FATAL_ERROR_INVALID_ARGS;
}
*sha1ModeResult = SHA1ModeResult::NeverChecked;
}
if (!cert ||
(usage != certificateUsageSSLServer && (flags & FLAG_MUST_BE_EV))) {
return Result::FATAL_ERROR_INVALID_ARGS;
}
Input certDER;
Result rv = certDER.Init(cert->derCert.data, cert->derCert.len);
if (rv != Success) {
return rv;
}
// We configure the OCSP fetching modes separately for EV and non-EV
// verifications.
NSSCertDBTrustDomain::OCSPFetching defaultOCSPFetching =
(mOCSPDownloadConfig == ocspOff) || (mOCSPDownloadConfig == ocspEVOnly) ||
(flags & FLAG_LOCAL_ONLY)
? NSSCertDBTrustDomain::NeverFetchOCSP
: !mOCSPStrict ? NSSCertDBTrustDomain::FetchOCSPForDVSoftFail
: NSSCertDBTrustDomain::FetchOCSPForDVHardFail;
Input stapledOCSPResponseInput;
const Input* stapledOCSPResponse = nullptr;
if (stapledOCSPResponseArg) {
rv = stapledOCSPResponseInput.Init(stapledOCSPResponseArg->Elements(),
stapledOCSPResponseArg->Length());
if (rv != Success) {
// The stapled OCSP response was too big.
return Result::ERROR_OCSP_MALFORMED_RESPONSE;
}
stapledOCSPResponse = &stapledOCSPResponseInput;
}
Input sctsFromTLSInput;
if (sctsFromTLS) {
rv = sctsFromTLSInput.Init(sctsFromTLS->Elements(), sctsFromTLS->Length());
if (rv != Success && sctsFromTLSInput.GetLength() != 0) {
return Result::FATAL_ERROR_LIBRARY_FAILURE;
}
}
switch (usage) {
case certificateUsageSSLClient: {
// XXX: We don't really have a trust bit for SSL client authentication so
// just use trustEmail as it is the closest alternative.
NSSCertDBTrustDomain trustDomain(
trustEmail, defaultOCSPFetching, mOCSPCache, pinArg, mOCSPTimeoutSoft,
mOCSPTimeoutHard, mCertShortLifetimeInDays, pinningDisabled,
MIN_RSA_BITS_WEAK, ValidityCheckingMode::CheckingOff,
SHA1Mode::Allowed, NetscapeStepUpPolicy::NeverMatch,
mDistrustedCAPolicy, mCRLiteMode, mCRLiteCTMergeDelaySeconds,
originAttributes, mThirdPartyRootInputs,
mThirdPartyIntermediateInputs, extraCertificates, builtChain, nullptr,
nullptr);
rv = BuildCertChain(
trustDomain, certDER, time, EndEntityOrCA::MustBeEndEntity,
KeyUsage::digitalSignature, KeyPurposeId::id_kp_clientAuth,
CertPolicyId::anyPolicy, stapledOCSPResponse);
break;
}
case certificateUsageSSLServer: {
// TODO: When verifying a certificate in an SSL handshake, we should
// restrict the acceptable key usage based on the key exchange method
// chosen by the server.
// These configurations are in order of most restrictive to least
// restrictive. This enables us to gather telemetry on the expected
// results of setting the default policy to a particular configuration.
SHA1Mode sha1ModeConfigurations[] = {
SHA1Mode::Forbidden,
SHA1Mode::ImportedRoot,
SHA1Mode::ImportedRootOrBefore2016,
SHA1Mode::Allowed,
};
SHA1ModeResult sha1ModeResults[] = {
SHA1ModeResult::SucceededWithoutSHA1,
SHA1ModeResult::SucceededWithImportedRoot,
SHA1ModeResult::SucceededWithImportedRootOrSHA1Before2016,
SHA1ModeResult::SucceededWithSHA1,
};
size_t sha1ModeConfigurationsCount =
MOZ_ARRAY_LENGTH(sha1ModeConfigurations);
static_assert(MOZ_ARRAY_LENGTH(sha1ModeConfigurations) ==
MOZ_ARRAY_LENGTH(sha1ModeResults),
"digestAlgorithm array lengths differ");
rv = Result::ERROR_UNKNOWN_ERROR;
// Try to validate for EV first.
NSSCertDBTrustDomain::OCSPFetching evOCSPFetching =
(mOCSPDownloadConfig == ocspOff) || (flags & FLAG_LOCAL_ONLY)
? NSSCertDBTrustDomain::LocalOnlyOCSPForEV
: NSSCertDBTrustDomain::FetchOCSPForEV;
CertPolicyId evPolicy;
SECOidTag evPolicyOidTag;
bool foundEVPolicy = GetFirstEVPolicy(*cert, evPolicy, evPolicyOidTag);
for (size_t i = 0;
i < sha1ModeConfigurationsCount && rv != Success && foundEVPolicy;
i++) {
// Don't attempt verification if the SHA1 mode set by preferences
// (mSHA1Mode) is more restrictive than the SHA1 mode option we're on.
// (To put it another way, only attempt verification if the SHA1 mode
// option we're on is as restrictive or more restrictive than
// mSHA1Mode.) This allows us to gather telemetry information while
// still enforcing the mode set by preferences.
if (SHA1ModeMoreRestrictiveThanGivenMode(sha1ModeConfigurations[i])) {
continue;
}
// Because of the try-strict and fallback approach, we have to clear any
// previously noted telemetry information.
if (pinningTelemetryInfo) {
pinningTelemetryInfo->Reset();
}
if (crliteInfo) {
crliteInfo->Reset();
}
NSSCertDBTrustDomain trustDomain(
trustSSL, evOCSPFetching, mOCSPCache, pinArg, mOCSPTimeoutSoft,
mOCSPTimeoutHard, mCertShortLifetimeInDays, mPinningMode,
MIN_RSA_BITS, ValidityCheckingMode::CheckForEV,
sha1ModeConfigurations[i], mNetscapeStepUpPolicy,
mDistrustedCAPolicy, mCRLiteMode, mCRLiteCTMergeDelaySeconds,
originAttributes, mThirdPartyRootInputs,
mThirdPartyIntermediateInputs, extraCertificates, builtChain,
pinningTelemetryInfo, crliteInfo, hostname);
rv = BuildCertChainForOneKeyUsage(
trustDomain, certDER, time,
KeyUsage::digitalSignature, // (EC)DHE
KeyUsage::keyEncipherment, // RSA
KeyUsage::keyAgreement, // (EC)DH
KeyPurposeId::id_kp_serverAuth, evPolicy, stapledOCSPResponse,
ocspStaplingStatus);
if (rv == Success &&
sha1ModeConfigurations[i] == SHA1Mode::ImportedRoot) {
bool isBuiltInRoot = false;
rv = IsCertChainRootBuiltInRoot(builtChain, isBuiltInRoot);
if (rv != Success) {
break;
}
if (isBuiltInRoot) {
rv = Result::ERROR_CERT_SIGNATURE_ALGORITHM_DISABLED;
}
}
if (rv == Success) {
MOZ_LOG(gCertVerifierLog, LogLevel::Debug,
("cert is EV with status %i\n",
static_cast<int>(sha1ModeResults[i])));
if (evOidPolicy) {
*evOidPolicy = evPolicyOidTag;
}
if (sha1ModeResult) {
*sha1ModeResult = sha1ModeResults[i];
}
rv = VerifyCertificateTransparencyPolicy(
trustDomain, builtChain, sctsFromTLSInput, time, ctInfo);
if (rv != Success) {
break;
}
}
}
if (rv == Success) {
break;
}
if (flags & FLAG_MUST_BE_EV) {
rv = Result::ERROR_POLICY_VALIDATION_FAILED;
break;
}
// Now try non-EV.
unsigned int keySizeOptions[] = {MIN_RSA_BITS, MIN_RSA_BITS_WEAK};
KeySizeStatus keySizeStatuses[] = {KeySizeStatus::LargeMinimumSucceeded,
KeySizeStatus::CompatibilityRisk};
static_assert(
MOZ_ARRAY_LENGTH(keySizeOptions) == MOZ_ARRAY_LENGTH(keySizeStatuses),
"keySize array lengths differ");
size_t keySizeOptionsCount = MOZ_ARRAY_LENGTH(keySizeStatuses);
for (size_t i = 0; i < keySizeOptionsCount && rv != Success; i++) {
for (size_t j = 0; j < sha1ModeConfigurationsCount && rv != Success;
j++) {
// Don't attempt verification if the SHA1 mode set by preferences
// (mSHA1Mode) is more restrictive than the SHA1 mode option we're on.
// (To put it another way, only attempt verification if the SHA1 mode
// option we're on is as restrictive or more restrictive than
// mSHA1Mode.) This allows us to gather telemetry information while
// still enforcing the mode set by preferences.
if (SHA1ModeMoreRestrictiveThanGivenMode(sha1ModeConfigurations[j])) {
continue;
}
// invalidate any telemetry info relating to failed chains
if (pinningTelemetryInfo) {
pinningTelemetryInfo->Reset();
}
if (crliteInfo) {
crliteInfo->Reset();
}
NSSCertDBTrustDomain trustDomain(
trustSSL, defaultOCSPFetching, mOCSPCache, pinArg,
mOCSPTimeoutSoft, mOCSPTimeoutHard, mCertShortLifetimeInDays,
mPinningMode, keySizeOptions[i],
ValidityCheckingMode::CheckingOff, sha1ModeConfigurations[j],
mNetscapeStepUpPolicy, mDistrustedCAPolicy, mCRLiteMode,
mCRLiteCTMergeDelaySeconds, originAttributes,
mThirdPartyRootInputs, mThirdPartyIntermediateInputs,
extraCertificates, builtChain, pinningTelemetryInfo, crliteInfo,
hostname);
rv = BuildCertChainForOneKeyUsage(
trustDomain, certDER, time,
KeyUsage::digitalSignature, //(EC)DHE
KeyUsage::keyEncipherment, // RSA
KeyUsage::keyAgreement, //(EC)DH
KeyPurposeId::id_kp_serverAuth, CertPolicyId::anyPolicy,
stapledOCSPResponse, ocspStaplingStatus);
if (rv != Success && !IsFatalError(rv) &&
rv != Result::ERROR_REVOKED_CERTIFICATE &&
trustDomain.GetIsErrorDueToDistrustedCAPolicy()) {
// Bug 1444440 - If there are multiple paths, at least one to a CA
// distrusted-by-policy, and none of them ending in a trusted root,
// then we might show a different error (UNKNOWN_ISSUER) than we
// intend, confusing users.
rv = Result::ERROR_ADDITIONAL_POLICY_CONSTRAINT_FAILED;
}
if (rv == Success &&
sha1ModeConfigurations[j] == SHA1Mode::ImportedRoot) {
bool isBuiltInRoot = false;
rv = IsCertChainRootBuiltInRoot(builtChain, isBuiltInRoot);
if (rv != Success) {
break;
}
if (isBuiltInRoot) {
rv = Result::ERROR_CERT_SIGNATURE_ALGORITHM_DISABLED;
}
}
if (rv == Success) {
if (keySizeStatus) {
*keySizeStatus = keySizeStatuses[i];
}
if (sha1ModeResult) {
*sha1ModeResult = sha1ModeResults[j];
}
rv = VerifyCertificateTransparencyPolicy(
trustDomain, builtChain, sctsFromTLSInput, time, ctInfo);
if (rv != Success) {
break;
}
}
}
}
if (rv == Success) {
break;
}
if (keySizeStatus) {
*keySizeStatus = KeySizeStatus::AlreadyBad;
}
// The telemetry probe CERT_CHAIN_SHA1_POLICY_STATUS gives us feedback on
// the result of setting a specific policy. However, we don't want noise
// from users who have manually set the policy to something other than the
// default, so we only collect for ImportedRoot (which is the default).
if (sha1ModeResult && mSHA1Mode == SHA1Mode::ImportedRoot) {
*sha1ModeResult = SHA1ModeResult::Failed;
}
break;
}
case certificateUsageSSLCA: {
NSSCertDBTrustDomain trustDomain(
trustSSL, defaultOCSPFetching, mOCSPCache, pinArg, mOCSPTimeoutSoft,
mOCSPTimeoutHard, mCertShortLifetimeInDays, pinningDisabled,
MIN_RSA_BITS_WEAK, ValidityCheckingMode::CheckingOff,
SHA1Mode::Allowed, mNetscapeStepUpPolicy, mDistrustedCAPolicy,
mCRLiteMode, mCRLiteCTMergeDelaySeconds, originAttributes,
mThirdPartyRootInputs, mThirdPartyIntermediateInputs,
extraCertificates, builtChain, nullptr, nullptr);
rv = BuildCertChain(trustDomain, certDER, time, EndEntityOrCA::MustBeCA,
KeyUsage::keyCertSign, KeyPurposeId::id_kp_serverAuth,
CertPolicyId::anyPolicy, stapledOCSPResponse);
break;
}
case certificateUsageEmailSigner: {
NSSCertDBTrustDomain trustDomain(
trustEmail, defaultOCSPFetching, mOCSPCache, pinArg, mOCSPTimeoutSoft,
mOCSPTimeoutHard, mCertShortLifetimeInDays, pinningDisabled,
MIN_RSA_BITS_WEAK, ValidityCheckingMode::CheckingOff,
SHA1Mode::Allowed, NetscapeStepUpPolicy::NeverMatch,
mDistrustedCAPolicy, mCRLiteMode, mCRLiteCTMergeDelaySeconds,
originAttributes, mThirdPartyRootInputs,
mThirdPartyIntermediateInputs, extraCertificates, builtChain, nullptr,
nullptr);
rv = BuildCertChain(
trustDomain, certDER, time, EndEntityOrCA::MustBeEndEntity,
KeyUsage::digitalSignature, KeyPurposeId::id_kp_emailProtection,
CertPolicyId::anyPolicy, stapledOCSPResponse);
if (rv == Result::ERROR_INADEQUATE_KEY_USAGE) {
rv = BuildCertChain(
trustDomain, certDER, time, EndEntityOrCA::MustBeEndEntity,
KeyUsage::nonRepudiation, KeyPurposeId::id_kp_emailProtection,
CertPolicyId::anyPolicy, stapledOCSPResponse);
}
break;
}
case certificateUsageEmailRecipient: {
// TODO: The higher level S/MIME processing should pass in which key
// usage it is trying to verify for, and base its algorithm choices
// based on the result of the verification(s).
NSSCertDBTrustDomain trustDomain(
trustEmail, defaultOCSPFetching, mOCSPCache, pinArg, mOCSPTimeoutSoft,
mOCSPTimeoutHard, mCertShortLifetimeInDays, pinningDisabled,
MIN_RSA_BITS_WEAK, ValidityCheckingMode::CheckingOff,
SHA1Mode::Allowed, NetscapeStepUpPolicy::NeverMatch,
mDistrustedCAPolicy, mCRLiteMode, mCRLiteCTMergeDelaySeconds,
originAttributes, mThirdPartyRootInputs,
mThirdPartyIntermediateInputs, extraCertificates, builtChain, nullptr,
nullptr);
rv = BuildCertChain(trustDomain, certDER, time,
EndEntityOrCA::MustBeEndEntity,
KeyUsage::keyEncipherment, // RSA
KeyPurposeId::id_kp_emailProtection,
CertPolicyId::anyPolicy, stapledOCSPResponse);
if (rv == Result::ERROR_INADEQUATE_KEY_USAGE) {
rv = BuildCertChain(trustDomain, certDER, time,
EndEntityOrCA::MustBeEndEntity,
KeyUsage::keyAgreement, // ECDH/DH
KeyPurposeId::id_kp_emailProtection,
CertPolicyId::anyPolicy, stapledOCSPResponse);
}
break;
}
default:
rv = Result::FATAL_ERROR_INVALID_ARGS;
}
if (rv != Success) {
return rv;
}
return Success;
}
static bool CertIsSelfSigned(const UniqueCERTCertificate& cert, void* pinarg) {
if (!SECITEM_ItemsAreEqual(&cert->derIssuer, &cert->derSubject)) {
return false;
}
// Check that the certificate is signed with the cert's spki.
SECStatus rv = CERT_VerifySignedDataWithPublicKeyInfo(
const_cast<CERTSignedData*>(&cert->signatureWrap),
const_cast<CERTSubjectPublicKeyInfo*>(&cert->subjectPublicKeyInfo),
pinarg);
if (rv != SECSuccess) {
return false;
}
return true;
}
Result CertVerifier::VerifySSLServerCert(
const UniqueCERTCertificate& peerCert, Time time,
/*optional*/ void* pinarg, const nsACString& hostname,
/*out*/ UniqueCERTCertList& builtChain,
/*optional*/ Flags flags,
/*optional*/ const Maybe<nsTArray<nsTArray<uint8_t>>>& extraCertificates,
/*optional*/ const Maybe<nsTArray<uint8_t>>& stapledOCSPResponse,
/*optional*/ const Maybe<nsTArray<uint8_t>>& sctsFromTLS,
/*optional*/ const Maybe<DelegatedCredentialInfo>& dcInfo,
/*optional*/ const OriginAttributes& originAttributes,
/*optional*/ bool saveIntermediatesInPermanentDatabase,
/*optional out*/ SECOidTag* evOidPolicy,
/*optional out*/ OCSPStaplingStatus* ocspStaplingStatus,
/*optional out*/ KeySizeStatus* keySizeStatus,
/*optional out*/ SHA1ModeResult* sha1ModeResult,
/*optional out*/ PinningTelemetryInfo* pinningTelemetryInfo,
/*optional out*/ CertificateTransparencyInfo* ctInfo,
/*optional out*/ CRLiteTelemetryInfo* crliteInfo,
/*optional out*/ bool* isBuiltCertChainRootBuiltInRoot) {
MOZ_ASSERT(peerCert);
// XXX: MOZ_ASSERT(pinarg);
MOZ_ASSERT(!hostname.IsEmpty());
SECOidTag evPolicyOidTag = SEC_OID_UNKNOWN;
if (isBuiltCertChainRootBuiltInRoot) {
*isBuiltCertChainRootBuiltInRoot = false;
}
if (evOidPolicy) {
*evOidPolicy = evPolicyOidTag;
}
if (hostname.IsEmpty()) {
return Result::ERROR_BAD_CERT_DOMAIN;
}
// CreateCertErrorRunnable assumes that CheckCertHostname is only called
// if VerifyCert succeeded.
Result rv = VerifyCert(peerCert.get(), certificateUsageSSLServer, time,
pinarg, PromiseFlatCString(hostname).get(), builtChain,
flags, extraCertificates, stapledOCSPResponse,
sctsFromTLS, originAttributes, &evPolicyOidTag,
ocspStaplingStatus, keySizeStatus, sha1ModeResult,
pinningTelemetryInfo, ctInfo, crliteInfo);
if (rv != Success) {
if (rv == Result::ERROR_UNKNOWN_ISSUER &&
CertIsSelfSigned(peerCert, pinarg)) {
// In this case we didn't find any issuer for the certificate and the
// certificate is self-signed.
return Result::ERROR_SELF_SIGNED_CERT;
}
if (rv == Result::ERROR_UNKNOWN_ISSUER) {
// In this case we didn't get any valid path for the cert. Let's see if
// the issuer is the same as the issuer for our canary probe. If yes, this
// connection is connecting via a misconfigured proxy.
// Note: The MitM canary might not be set. In this case we consider this
// an unknown issuer error.
nsCOMPtr<nsINSSComponent> component(
do_GetService(PSM_COMPONENT_CONTRACTID));
if (!component) {
return Result::FATAL_ERROR_LIBRARY_FAILURE;
}
// IssuerMatchesMitmCanary succeeds if the issuer matches the canary and
// the feature is enabled.
nsresult rv = component->IssuerMatchesMitmCanary(peerCert->issuerName);
if (NS_SUCCEEDED(rv)) {
return Result::ERROR_MITM_DETECTED;
}
}
return rv;
}
if (dcInfo) {
rv = IsDelegatedCredentialAcceptable(*dcInfo, evPolicyOidTag);
if (rv != Success) {
return rv;
}
}
Input peerCertInput;
rv = peerCertInput.Init(peerCert->derCert.data, peerCert->derCert.len);
if (rv != Success) {
return rv;
}
Input stapledOCSPResponseInput;
Input* responseInputPtr = nullptr;
if (stapledOCSPResponse) {
rv = stapledOCSPResponseInput.Init(stapledOCSPResponse->Elements(),
stapledOCSPResponse->Length());
if (rv != Success) {
// The stapled OCSP response was too big.
return Result::ERROR_OCSP_MALFORMED_RESPONSE;
}
responseInputPtr = &stapledOCSPResponseInput;
}
if (!(flags & FLAG_TLS_IGNORE_STATUS_REQUEST)) {
rv = CheckTLSFeaturesAreSatisfied(peerCertInput, responseInputPtr);
if (rv != Success) {
return rv;
}
}
Input hostnameInput;
rv = hostnameInput.Init(
BitwiseCast<const uint8_t*, const char*>(hostname.BeginReading()),
hostname.Length());
if (rv != Success) {
return Result::FATAL_ERROR_INVALID_ARGS;
}
bool isBuiltInRoot;
rv = IsCertChainRootBuiltInRoot(builtChain, isBuiltInRoot);
if (rv != Success) {
return rv;
}
if (isBuiltCertChainRootBuiltInRoot) {
*isBuiltCertChainRootBuiltInRoot = isBuiltInRoot;
}
BRNameMatchingPolicy nameMatchingPolicy(
isBuiltInRoot ? mNameMatchingMode
: BRNameMatchingPolicy::Mode::DoNotEnforce);
rv = CheckCertHostname(peerCertInput, hostnameInput, nameMatchingPolicy);
if (rv != Success) {
// Treat malformed name information as a domain mismatch.
if (rv == Result::ERROR_BAD_DER) {
return Result::ERROR_BAD_CERT_DOMAIN;
}
return rv;
}
if (saveIntermediatesInPermanentDatabase) {
SaveIntermediateCerts(builtChain);
}
if (evOidPolicy) {
*evOidPolicy = evPolicyOidTag;
}
return Success;
}
} // namespace psm
} // namespace mozilla