naiveproxy/net/cert/cert_verify_proc.cc
2018-08-11 05:35:24 +00:00

912 lines
34 KiB
C++

// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "net/cert/cert_verify_proc.h"
#include <stdint.h>
#include <algorithm>
#include "base/containers/span.h"
#include "base/metrics/histogram.h"
#include "base/metrics/histogram_functions.h"
#include "base/metrics/histogram_macros.h"
#include "base/sha1.h"
#include "base/stl_util.h"
#include "base/strings/string_util.h"
#include "base/strings/stringprintf.h"
#include "base/threading/scoped_blocking_call.h"
#include "base/time/time.h"
#include "build/build_config.h"
#include "crypto/sha2.h"
#include "net/base/net_errors.h"
#include "net/base/registry_controlled_domains/registry_controlled_domain.h"
#include "net/base/url_util.h"
#include "net/cert/asn1_util.h"
#include "net/cert/cert_status_flags.h"
#include "net/cert/cert_verifier.h"
#include "net/cert/cert_verify_result.h"
#include "net/cert/crl_set.h"
#include "net/cert/internal/ocsp.h"
#include "net/cert/internal/signature_algorithm.h"
#include "net/cert/known_roots.h"
#include "net/cert/ocsp_revocation_status.h"
#include "net/cert/symantec_certs.h"
#include "net/cert/x509_certificate.h"
#include "net/cert/x509_util.h"
#include "net/der/encode_values.h"
#include "url/url_canon.h"
#if defined(USE_NSS_CERTS)
#include "net/cert/cert_verify_proc_nss.h"
#elif defined(OS_ANDROID)
#include "net/cert/cert_verify_proc_android.h"
#elif defined(OS_IOS)
#include "net/cert/cert_verify_proc_ios.h"
#elif defined(OS_MACOSX)
#include "net/cert/cert_verify_proc_mac.h"
#elif defined(OS_WIN)
#include "base/win/windows_version.h"
#include "net/cert/cert_verify_proc_win.h"
#elif defined(OS_FUCHSIA)
#include "net/cert/cert_verify_proc_builtin.h"
#else
#error Implement certificate verification.
#endif
namespace net {
namespace {
// Constants used to build histogram names
const char kLeafCert[] = "Leaf";
const char kIntermediateCert[] = "Intermediate";
const char kRootCert[] = "Root";
// Histogram buckets for RSA/DSA/DH key sizes.
const int kRsaDsaKeySizes[] = {512, 768, 1024, 1536, 2048, 3072, 4096, 8192,
16384};
// Histogram buckets for ECDSA/ECDH key sizes. The list is based upon the FIPS
// 186-4 approved curves.
const int kEccKeySizes[] = {163, 192, 224, 233, 256, 283, 384, 409, 521, 571};
const char* CertTypeToString(X509Certificate::PublicKeyType cert_type) {
switch (cert_type) {
case X509Certificate::kPublicKeyTypeUnknown:
return "Unknown";
case X509Certificate::kPublicKeyTypeRSA:
return "RSA";
case X509Certificate::kPublicKeyTypeDSA:
return "DSA";
case X509Certificate::kPublicKeyTypeECDSA:
return "ECDSA";
case X509Certificate::kPublicKeyTypeDH:
return "DH";
case X509Certificate::kPublicKeyTypeECDH:
return "ECDH";
}
NOTREACHED();
return "Unsupported";
}
void RecordPublicKeyHistogram(const char* chain_position,
bool baseline_keysize_applies,
size_t size_bits,
X509Certificate::PublicKeyType cert_type) {
std::string histogram_name =
base::StringPrintf("CertificateType2.%s.%s.%s",
baseline_keysize_applies ? "BR" : "NonBR",
chain_position,
CertTypeToString(cert_type));
// Do not use UMA_HISTOGRAM_... macros here, as it caches the Histogram
// instance and thus only works if |histogram_name| is constant.
base::HistogramBase* counter = NULL;
// Histogram buckets are contingent upon the underlying algorithm being used.
if (cert_type == X509Certificate::kPublicKeyTypeECDH ||
cert_type == X509Certificate::kPublicKeyTypeECDSA) {
// Typical key sizes match SECP/FIPS 186-3 recommendations for prime and
// binary curves - which range from 163 bits to 571 bits.
counter = base::CustomHistogram::FactoryGet(
histogram_name,
base::CustomHistogram::ArrayToCustomEnumRanges(kEccKeySizes),
base::HistogramBase::kUmaTargetedHistogramFlag);
} else {
// Key sizes < 1024 bits should cause errors, while key sizes > 16K are not
// uniformly supported by the underlying cryptographic libraries.
counter = base::CustomHistogram::FactoryGet(
histogram_name,
base::CustomHistogram::ArrayToCustomEnumRanges(kRsaDsaKeySizes),
base::HistogramBase::kUmaTargetedHistogramFlag);
}
counter->Add(size_bits);
}
// Returns true if |type| is |kPublicKeyTypeRSA| or |kPublicKeyTypeDSA|, and
// if |size_bits| is < 1024. Note that this means there may be false
// negatives: keys for other algorithms and which are weak will pass this
// test.
bool IsWeakKey(X509Certificate::PublicKeyType type, size_t size_bits) {
switch (type) {
case X509Certificate::kPublicKeyTypeRSA:
case X509Certificate::kPublicKeyTypeDSA:
return size_bits < 1024;
default:
return false;
}
}
// Returns true if |cert| contains a known-weak key. Additionally, histograms
// the observed keys for future tightening of the definition of what
// constitutes a weak key.
bool ExaminePublicKeys(const scoped_refptr<X509Certificate>& cert,
bool should_histogram) {
// The effective date of the CA/Browser Forum's Baseline Requirements -
// 2012-07-01 00:00:00 UTC.
const base::Time kBaselineEffectiveDate =
base::Time::FromInternalValue(INT64_C(12985574400000000));
// The effective date of the key size requirements from Appendix A, v1.1.5
// 2014-01-01 00:00:00 UTC.
const base::Time kBaselineKeysizeEffectiveDate =
base::Time::FromInternalValue(INT64_C(13033008000000000));
size_t size_bits = 0;
X509Certificate::PublicKeyType type = X509Certificate::kPublicKeyTypeUnknown;
bool weak_key = false;
bool baseline_keysize_applies =
cert->valid_start() >= kBaselineEffectiveDate &&
cert->valid_expiry() >= kBaselineKeysizeEffectiveDate;
X509Certificate::GetPublicKeyInfo(cert->cert_buffer(), &size_bits, &type);
if (should_histogram) {
RecordPublicKeyHistogram(kLeafCert, baseline_keysize_applies, size_bits,
type);
}
if (IsWeakKey(type, size_bits))
weak_key = true;
const std::vector<bssl::UniquePtr<CRYPTO_BUFFER>>& intermediates =
cert->intermediate_buffers();
for (size_t i = 0; i < intermediates.size(); ++i) {
X509Certificate::GetPublicKeyInfo(intermediates[i].get(), &size_bits,
&type);
if (should_histogram) {
RecordPublicKeyHistogram(
(i < intermediates.size() - 1) ? kIntermediateCert : kRootCert,
baseline_keysize_applies,
size_bits,
type);
}
if (!weak_key && IsWeakKey(type, size_bits))
weak_key = true;
}
return weak_key;
}
// Beginning with Ballot 118, ratified in the Baseline Requirements v1.2.1,
// CAs MUST NOT issue SHA-1 certificates beginning on 1 January 2016.
bool IsPastSHA1DeprecationDate(const X509Certificate& cert) {
const base::Time& start = cert.valid_start();
if (start.is_max() || start.is_null())
return true;
// 2016-01-01 00:00:00 UTC.
const base::Time kSHA1DeprecationDate =
base::Time::FromInternalValue(INT64_C(13096080000000000));
return start >= kSHA1DeprecationDate;
}
// See
// https://security.googleblog.com/2017/09/chromes-plan-to-distrust-symantec.html
// for more details.
bool IsUntrustedSymantecCert(const X509Certificate& cert) {
const base::Time& start = cert.valid_start();
if (start.is_max() || start.is_null())
return true;
// Certificates issued on/after 2017-12-01 00:00:00 UTC are no longer
// trusted.
const base::Time kSymantecDeprecationDate =
base::Time::UnixEpoch() + base::TimeDelta::FromSeconds(1512086400);
if (start >= kSymantecDeprecationDate)
return true;
// Certificates issued prior to 2016-06-01 00:00:00 UTC are no longer
// trusted.
const base::Time kFirstAcceptedCertDate =
base::Time::UnixEpoch() + base::TimeDelta::FromSeconds(1464739200);
if (start < kFirstAcceptedCertDate)
return true;
return false;
}
void BestEffortCheckOCSP(const std::string& raw_response,
const X509Certificate& certificate,
OCSPVerifyResult* verify_result) {
if (raw_response.empty()) {
*verify_result = OCSPVerifyResult();
verify_result->response_status = OCSPVerifyResult::MISSING;
return;
}
base::StringPiece cert_der =
x509_util::CryptoBufferAsStringPiece(certificate.cert_buffer());
// Try to get the certificate that signed |certificate|. This will run into
// problems if the CertVerifyProc implementation doesn't return the ordered
// certificates. If that happens the OCSP verification may be incorrect.
base::StringPiece issuer_der;
if (certificate.intermediate_buffers().empty()) {
if (X509Certificate::IsSelfSigned(certificate.cert_buffer())) {
issuer_der = cert_der;
} else {
// A valid cert chain wasn't provided.
*verify_result = OCSPVerifyResult();
return;
}
} else {
issuer_der = x509_util::CryptoBufferAsStringPiece(
certificate.intermediate_buffers().front().get());
}
verify_result->revocation_status =
CheckOCSP(raw_response, cert_der, issuer_der, base::Time::Now(),
kMaxOCSPLeafUpdateAge, &verify_result->response_status);
}
// Records histograms indicating whether the certificate |cert|, which
// is assumed to have been validated chaining to a private root,
// contains the TLS Feature Extension (https://tools.ietf.org/html/rfc7633) and
// has valid OCSP information stapled.
void RecordTLSFeatureExtensionWithPrivateRoot(
X509Certificate* cert,
const OCSPVerifyResult& ocsp_result) {
// This checks only for the presence of the TLS Feature Extension, but
// does not check the feature list, and in particular does not verify that
// its value is 'status_request' or 'status_request2'. In practice the
// only use of the TLS feature extension is for OCSP stapling, so
// don't bother to check the value.
bool has_extension = asn1::HasTLSFeatureExtension(
x509_util::CryptoBufferAsStringPiece(cert->cert_buffer()));
UMA_HISTOGRAM_BOOLEAN("Net.Certificate.TLSFeatureExtensionWithPrivateRoot",
has_extension);
if (!has_extension)
return;
UMA_HISTOGRAM_BOOLEAN(
"Net.Certificate.TLSFeatureExtensionWithPrivateRootHasOCSP",
(ocsp_result.response_status != OCSPVerifyResult::MISSING));
}
// Records details about the most-specific trust anchor in |hashes|, which is
// expected to be ordered with the leaf cert first and the root cert last.
// "Most-specific" refers to the case that it is not uncommon to have multiple
// potential trust anchors present in a chain, depending on the client trust
// store. For example, '1999-Root' cross-signing '2005-Root' cross-signing
// '2012-Root' cross-signing '2017-Root', then followed by intermediate and
// leaf. For purposes of assessing impact of, say, removing 1999-Root, while
// including 2017-Root as a trust anchor, then the validation should be
// counted as 2017-Root, rather than 1999-Root.
//
// This also accounts for situations in which a new CA is introduced, and
// has been cross-signed by an existing CA. Assessing impact should use the
// most-specific trust anchor, when possible.
//
// This also histograms for divergence between the root store and
// |spki_hashes| - that is, situations in which the OS methods of detecting
// a known root flag a certificate as known, but its hash is not known as part
// of the built-in list.
void RecordTrustAnchorHistogram(const HashValueVector& spki_hashes,
bool is_issued_by_known_root) {
int32_t id = 0;
for (const auto& hash : spki_hashes) {
id = GetNetTrustAnchorHistogramIdForSPKI(hash);
if (id != 0)
break;
}
base::UmaHistogramSparse("Net.Certificate.TrustAnchor.Verify", id);
// Record when a known trust anchor is not found within the chain, but the
// certificate is flagged as being from a known root (meaning a fallback to
// OS-based methods of determination).
if (id == 0) {
UMA_HISTOGRAM_BOOLEAN("Net.Certificate.TrustAnchor.VerifyOutOfDate",
is_issued_by_known_root);
}
}
// Comparison functor used for binary searching whether a given HashValue,
// which MUST be a SHA-256 hash, is contained with an array of SHA-256
// hashes.
struct HashToArrayComparator {
template <size_t N>
bool operator()(const uint8_t(&lhs)[N], const HashValue& rhs) const {
static_assert(N == crypto::kSHA256Length,
"Only SHA-256 hashes are supported");
return memcmp(lhs, rhs.data(), crypto::kSHA256Length) < 0;
}
template <size_t N>
bool operator()(const HashValue& lhs, const uint8_t(&rhs)[N]) const {
static_assert(N == crypto::kSHA256Length,
"Only SHA-256 hashes are supported");
return memcmp(lhs.data(), rhs, crypto::kSHA256Length) < 0;
}
};
bool AreSHA1IntermediatesAllowed() {
#if defined(OS_WIN)
// TODO(rsleevi): Remove this once https://crbug.com/588789 is resolved
// for Windows 7/2008 users.
// Note: This must be kept in sync with cert_verify_proc_unittest.cc
return base::win::GetVersion() < base::win::VERSION_WIN8;
#else
return false;
#endif
};
// Sets the "has_*" boolean members in |verify_result| that correspond with
// the the presence of |hash| somewhere in the certificate chain (excluding the
// trust anchor).
void MapAlgorithmToBool(DigestAlgorithm hash, CertVerifyResult* verify_result) {
switch (hash) {
case DigestAlgorithm::Md2:
verify_result->has_md2 = true;
break;
case DigestAlgorithm::Md4:
verify_result->has_md4 = true;
break;
case DigestAlgorithm::Md5:
verify_result->has_md5 = true;
break;
case DigestAlgorithm::Sha1:
verify_result->has_sha1 = true;
break;
case DigestAlgorithm::Sha256:
case DigestAlgorithm::Sha384:
case DigestAlgorithm::Sha512:
break;
}
}
// Inspects the signature algorithms in a single certificate |cert|.
//
// * Sets |verify_result->has_md2| to true if the certificate uses MD2.
// * Sets |verify_result->has_md4| to true if the certificate uses MD4.
// * Sets |verify_result->has_md5| to true if the certificate uses MD5.
// * Sets |verify_result->has_sha1| to true if the certificate uses SHA1.
//
// Returns false if the signature algorithm was unknown or mismatched.
WARN_UNUSED_RESULT bool InspectSignatureAlgorithmForCert(
const CRYPTO_BUFFER* cert,
CertVerifyResult* verify_result) {
base::StringPiece cert_algorithm_sequence;
base::StringPiece tbs_algorithm_sequence;
// Extract the AlgorithmIdentifier SEQUENCEs
if (!asn1::ExtractSignatureAlgorithmsFromDERCert(
x509_util::CryptoBufferAsStringPiece(cert), &cert_algorithm_sequence,
&tbs_algorithm_sequence)) {
return false;
}
if (!SignatureAlgorithm::IsEquivalent(der::Input(cert_algorithm_sequence),
der::Input(tbs_algorithm_sequence))) {
return false;
}
std::unique_ptr<SignatureAlgorithm> algorithm =
SignatureAlgorithm::Create(der::Input(cert_algorithm_sequence), nullptr);
if (!algorithm)
return false;
MapAlgorithmToBool(algorithm->digest(), verify_result);
// Check algorithm-specific parameters.
switch (algorithm->algorithm()) {
case SignatureAlgorithmId::Dsa:
case SignatureAlgorithmId::RsaPkcs1:
case SignatureAlgorithmId::Ecdsa:
DCHECK(!algorithm->has_params());
break;
case SignatureAlgorithmId::RsaPss:
MapAlgorithmToBool(algorithm->ParamsForRsaPss()->mgf1_hash(),
verify_result);
break;
}
return true;
}
// InspectSignatureAlgorithmsInChain() sets |verify_result->has_*| based on
// the signature algorithms used in the chain, and also checks that certificates
// don't have contradictory signature algorithms.
//
// Returns false if any signature algorithm in the chain is unknown or
// mismatched.
//
// Background:
//
// X.509 certificates contain two redundant descriptors for the signature
// algorithm; one is covered by the signature, but in order to verify the
// signature, the other signature algorithm is untrusted.
//
// RFC 5280 states that the two should be equal, in order to mitigate risk of
// signature substitution attacks, but also discourages verifiers from enforcing
// the profile of RFC 5280.
//
// System verifiers are inconsistent - some use the unsigned signature, some use
// the signed signature, and they generally do not enforce that both match. This
// creates confusion, as it's possible that the signature itself may be checked
// using algorithm A, but if subsequent consumers report the certificate
// algorithm, they may end up reporting algorithm B, which was not used to
// verify the certificate. This function enforces that the two signatures match
// in order to prevent such confusion.
WARN_UNUSED_RESULT bool InspectSignatureAlgorithmsInChain(
CertVerifyResult* verify_result) {
const std::vector<bssl::UniquePtr<CRYPTO_BUFFER>>& intermediates =
verify_result->verified_cert->intermediate_buffers();
// If there are no intermediates, then the leaf is trusted or verification
// failed.
if (intermediates.empty())
return true;
DCHECK(!verify_result->has_sha1);
// Fill in hash algorithms for the leaf certificate.
if (!InspectSignatureAlgorithmForCert(
verify_result->verified_cert->cert_buffer(), verify_result)) {
return false;
}
verify_result->has_sha1_leaf = verify_result->has_sha1;
// Fill in hash algorithms for the intermediate cerificates, excluding the
// final one (which is presumably the trust anchor; may be incorrect for
// partial chains).
for (size_t i = 0; i + 1 < intermediates.size(); ++i) {
if (!InspectSignatureAlgorithmForCert(intermediates[i].get(),
verify_result))
return false;
}
return true;
}
} // namespace
// static
scoped_refptr<CertVerifyProc> CertVerifyProc::CreateDefault() {
#if defined(USE_NSS_CERTS)
return new CertVerifyProcNSS();
#elif defined(OS_ANDROID)
return new CertVerifyProcAndroid();
#elif defined(OS_IOS)
return new CertVerifyProcIOS();
#elif defined(OS_MACOSX)
return new CertVerifyProcMac();
#elif defined(OS_WIN)
return new CertVerifyProcWin();
#elif defined(OS_FUCHSIA)
return CreateCertVerifyProcBuiltin();
#else
#error Unsupported platform
#endif
}
CertVerifyProc::CertVerifyProc()
: sha1_legacy_mode_enabled(base::FeatureList::IsEnabled(kSHA1LegacyMode)) {}
CertVerifyProc::~CertVerifyProc() = default;
int CertVerifyProc::Verify(X509Certificate* cert,
const std::string& hostname,
const std::string& ocsp_response,
int flags,
CRLSet* crl_set,
const CertificateList& additional_trust_anchors,
CertVerifyResult* verify_result) {
// CertVerifyProc's contract allows ::VerifyInternal() to wait on File I/O
// (such as the Windows registry or smart cards on all platforms) or may re-
// enter this code via extension hooks (such as smart card UI). To ensure
// threads are not starved or deadlocked, the base::ScopedBlockingCall below
// increments the thread pool capacity when this method takes too much time to
// run.
base::ScopedBlockingCall scoped_blocking_call(base::BlockingType::MAY_BLOCK);
verify_result->Reset();
verify_result->verified_cert = cert;
if (IsBlacklisted(cert)) {
verify_result->cert_status |= CERT_STATUS_REVOKED;
return ERR_CERT_REVOKED;
}
int rv = VerifyInternal(cert, hostname, ocsp_response, flags, crl_set,
additional_trust_anchors, verify_result);
// Check for mismatched signature algorithms and unknown signature algorithms
// in the chain. Also fills in the has_* booleans for the digest algorithms
// present in the chain.
if (!InspectSignatureAlgorithmsInChain(verify_result)) {
verify_result->cert_status |= CERT_STATUS_INVALID;
rv = MapCertStatusToNetError(verify_result->cert_status);
}
if (!cert->VerifyNameMatch(hostname)) {
verify_result->cert_status |= CERT_STATUS_COMMON_NAME_INVALID;
rv = MapCertStatusToNetError(verify_result->cert_status);
}
BestEffortCheckOCSP(ocsp_response, *verify_result->verified_cert,
&verify_result->ocsp_result);
// This check is done after VerifyInternal so that VerifyInternal can fill
// in the list of public key hashes.
if (IsPublicKeyBlacklisted(verify_result->public_key_hashes)) {
verify_result->cert_status |= CERT_STATUS_REVOKED;
rv = MapCertStatusToNetError(verify_result->cert_status);
}
std::vector<std::string> dns_names, ip_addrs;
cert->GetSubjectAltName(&dns_names, &ip_addrs);
if (HasNameConstraintsViolation(verify_result->public_key_hashes,
cert->subject().common_name,
dns_names,
ip_addrs)) {
verify_result->cert_status |= CERT_STATUS_NAME_CONSTRAINT_VIOLATION;
rv = MapCertStatusToNetError(verify_result->cert_status);
}
// Check for weak keys in the entire verified chain.
bool weak_key = ExaminePublicKeys(verify_result->verified_cert,
verify_result->is_issued_by_known_root);
if (weak_key) {
verify_result->cert_status |= CERT_STATUS_WEAK_KEY;
// Avoid replacing a more serious error, such as an OS/library failure,
// by ensuring that if verification failed, it failed with a certificate
// error.
if (rv == OK || IsCertificateError(rv))
rv = MapCertStatusToNetError(verify_result->cert_status);
}
// Treat certificates signed using broken signature algorithms as invalid.
if (verify_result->has_md2 || verify_result->has_md4) {
verify_result->cert_status |= CERT_STATUS_INVALID;
rv = MapCertStatusToNetError(verify_result->cert_status);
}
if (verify_result->has_sha1)
verify_result->cert_status |= CERT_STATUS_SHA1_SIGNATURE_PRESENT;
// Flag certificates using weak signature algorithms.
// Legacy SHA-1 behaviour:
// - Reject all publicly trusted SHA-1 leaf certs issued after
// 2016-01-01.
bool legacy_sha1_issue = verify_result->has_sha1_leaf &&
verify_result->is_issued_by_known_root &&
IsPastSHA1DeprecationDate(*cert);
// Current SHA-1 behaviour:
// - Reject all SHA-1
// - ... unless it's not publicly trusted and SHA-1 is allowed
// - ... or SHA-1 is in the intermediate and SHA-1 intermediates are
// allowed for that platform. See https://crbug.com/588789
bool current_sha1_issue =
(verify_result->is_issued_by_known_root ||
!(flags & CertVerifier::VERIFY_ENABLE_SHA1_LOCAL_ANCHORS)) &&
(verify_result->has_sha1_leaf ||
(verify_result->has_sha1 && !AreSHA1IntermediatesAllowed()));
if (verify_result->has_md5 ||
(sha1_legacy_mode_enabled && legacy_sha1_issue) ||
(!sha1_legacy_mode_enabled && current_sha1_issue)) {
verify_result->cert_status |= CERT_STATUS_WEAK_SIGNATURE_ALGORITHM;
// Avoid replacing a more serious error, such as an OS/library failure,
// by ensuring that if verification failed, it failed with a certificate
// error.
if (rv == OK || IsCertificateError(rv))
rv = MapCertStatusToNetError(verify_result->cert_status);
}
// Distrust Symantec-issued certificates, as described at
// https://security.googleblog.com/2017/09/chromes-plan-to-distrust-symantec.html
if (!(flags & CertVerifier::VERIFY_DISABLE_SYMANTEC_ENFORCEMENT) &&
IsLegacySymantecCert(verify_result->public_key_hashes)) {
if (IsUntrustedSymantecCert(*verify_result->verified_cert)) {
verify_result->cert_status |= CERT_STATUS_SYMANTEC_LEGACY;
if (rv == OK || IsCertificateError(rv))
rv = MapCertStatusToNetError(verify_result->cert_status);
}
}
// Flag certificates from publicly-trusted CAs that are issued to intranet
// hosts. While the CA/Browser Forum Baseline Requirements (v1.1) permit
// these to be issued until 1 November 2015, they represent a real risk for
// the deployment of gTLDs and are being phased out ahead of the hard
// deadline.
if (verify_result->is_issued_by_known_root && IsHostnameNonUnique(hostname)) {
verify_result->cert_status |= CERT_STATUS_NON_UNIQUE_NAME;
// CERT_STATUS_NON_UNIQUE_NAME will eventually become a hard error. For
// now treat it as a warning and do not map it to an error return value.
}
// Flag certificates using too long validity periods.
if (verify_result->is_issued_by_known_root && HasTooLongValidity(*cert)) {
verify_result->cert_status |= CERT_STATUS_VALIDITY_TOO_LONG;
if (rv == OK)
rv = MapCertStatusToNetError(verify_result->cert_status);
}
// Record a histogram for the presence of the TLS feature extension in
// a certificate chaining to a private root.
if (rv == OK && !verify_result->is_issued_by_known_root)
RecordTLSFeatureExtensionWithPrivateRoot(cert, verify_result->ocsp_result);
// Record a histogram for per-verification usage of root certs.
if (rv == OK) {
RecordTrustAnchorHistogram(verify_result->public_key_hashes,
verify_result->is_issued_by_known_root);
}
return rv;
}
// static
bool CertVerifyProc::IsBlacklisted(X509Certificate* cert) {
// CloudFlare revoked all certificates issued prior to April 2nd, 2014. Thus
// all certificates where the CN ends with ".cloudflare.com" with a prior
// issuance date are rejected.
//
// The old certs had a lifetime of five years, so this can be removed April
// 2nd, 2019.
const base::StringPiece cn(cert->subject().common_name);
static constexpr base::StringPiece kCloudflareCNSuffix(".cloudflare.com");
// April 2nd, 2014 UTC, expressed as seconds since the Unix Epoch.
static constexpr base::TimeDelta kCloudflareEpoch =
base::TimeDelta::FromSeconds(1396396800);
if (cn.ends_with(kCloudflareCNSuffix) &&
cert->valid_start() < (base::Time::UnixEpoch() + kCloudflareEpoch)) {
return true;
}
return false;
}
// static
bool CertVerifyProc::IsPublicKeyBlacklisted(
const HashValueVector& public_key_hashes) {
// Defines kBlacklistedSPKIs.
#include "net/cert/cert_verify_proc_blacklist.inc"
for (const auto& hash : public_key_hashes) {
if (hash.tag() != HASH_VALUE_SHA256)
continue;
if (std::binary_search(std::begin(kBlacklistedSPKIs),
std::end(kBlacklistedSPKIs), hash,
HashToArrayComparator())) {
return true;
}
}
return false;
}
// CheckNameConstraints verifies that every name in |dns_names| is in one of
// the domains specified by |domains|.
static bool CheckNameConstraints(const std::vector<std::string>& dns_names,
base::span<const base::StringPiece> domains) {
for (const auto& host : dns_names) {
bool ok = false;
url::CanonHostInfo host_info;
const std::string dns_name = CanonicalizeHost(host, &host_info);
if (host_info.IsIPAddress())
continue;
// If the name is not in a known TLD, ignore it. This permits internal
// server names.
if (!registry_controlled_domains::HostHasRegistryControlledDomain(
dns_name, registry_controlled_domains::EXCLUDE_UNKNOWN_REGISTRIES,
registry_controlled_domains::INCLUDE_PRIVATE_REGISTRIES)) {
continue;
}
for (const auto& domain : domains) {
// The |domain| must be of ".somesuffix" form, and |dns_name| must
// have |domain| as a suffix.
DCHECK_EQ('.', domain[0]);
if (dns_name.size() <= domain.size())
continue;
base::StringPiece suffix =
base::StringPiece(dns_name).substr(dns_name.size() - domain.size());
if (!base::LowerCaseEqualsASCII(suffix, domain))
continue;
ok = true;
break;
}
if (!ok)
return false;
}
return true;
}
// static
bool CertVerifyProc::HasNameConstraintsViolation(
const HashValueVector& public_key_hashes,
const std::string& common_name,
const std::vector<std::string>& dns_names,
const std::vector<std::string>& ip_addrs) {
static constexpr base::StringPiece kDomainsANSSI[] = {
".fr", // France
".gp", // Guadeloupe
".gf", // Guyane
".mq", // Martinique
".re", // Réunion
".yt", // Mayotte
".pm", // Saint-Pierre et Miquelon
".bl", // Saint Barthélemy
".mf", // Saint Martin
".wf", // Wallis et Futuna
".pf", // Polynésie française
".nc", // Nouvelle Calédonie
".tf", // Terres australes et antarctiques françaises
};
static constexpr base::StringPiece kDomainsIndiaCCA[] = {
".gov.in", ".nic.in", ".ac.in", ".rbi.org.in", ".bankofindia.co.in",
".ncode.in", ".tcs.co.in",
};
static constexpr base::StringPiece kDomainsTest[] = {
".example.com",
};
// PublicKeyDomainLimitation contains SHA-256(SPKI) and a pointer to an array
// of fixed-length strings that contain the domains that the SPKI is allowed
// to issue for.
static const struct PublicKeyDomainLimitation {
SHA256HashValue public_key_hash;
base::span<const base::StringPiece> domains;
} kLimits[] = {
// C=FR, ST=France, L=Paris, O=PM/SGDN, OU=DCSSI,
// CN=IGC/A/emailAddress=igca@sgdn.pm.gouv.fr
//
// net/data/ssl/blacklist/b9bea7860a962ea3611dab97ab6da3e21c1068b97d55575ed0e11279c11c8932.pem
{
{{0x86, 0xc1, 0x3a, 0x34, 0x08, 0xdd, 0x1a, 0xa7, 0x7e, 0xe8, 0xb6,
0x94, 0x7c, 0x03, 0x95, 0x87, 0x72, 0xf5, 0x31, 0x24, 0x8c, 0x16,
0x27, 0xbe, 0xfb, 0x2c, 0x4f, 0x4b, 0x04, 0xd0, 0x44, 0x96}},
kDomainsANSSI,
},
// C=IN, O=India PKI, CN=CCA India 2007
// Expires: July 4th 2015.
//
// net/data/ssl/blacklist/f375e2f77a108bacc4234894a9af308edeca1acd8fbde0e7aaa9634e9daf7e1c.pem
{
{{0x7e, 0x6a, 0xcd, 0x85, 0x3c, 0xac, 0xc6, 0x93, 0x2e, 0x9b, 0x51,
0x9f, 0xda, 0xd1, 0xbe, 0xb5, 0x15, 0xed, 0x2a, 0x2d, 0x00, 0x25,
0xcf, 0xd3, 0x98, 0xc3, 0xac, 0x1f, 0x0d, 0xbb, 0x75, 0x4b}},
kDomainsIndiaCCA,
},
// C=IN, O=India PKI, CN=CCA India 2011
// Expires: March 11 2016.
//
// net/data/ssl/blacklist/2d66a702ae81ba03af8cff55ab318afa919039d9f31b4d64388680f81311b65a.pem
{
{{0x42, 0xa7, 0x09, 0x84, 0xff, 0xd3, 0x99, 0xc4, 0xea, 0xf0, 0xe7,
0x02, 0xa4, 0x4b, 0xef, 0x2a, 0xd8, 0xa7, 0x9b, 0x8b, 0xf4, 0x64,
0x8f, 0x6b, 0xb2, 0x10, 0xe1, 0x23, 0xfd, 0x07, 0x57, 0x93}},
kDomainsIndiaCCA,
},
// C=IN, O=India PKI, CN=CCA India 2014
// Expires: March 5 2024.
//
// net/data/ssl/blacklist/60109bc6c38328598a112c7a25e38b0f23e5a7511cb815fb64e0c4ff05db7df7.pem
{
{{0x9c, 0xf4, 0x70, 0x4f, 0x3e, 0xe5, 0xa5, 0x98, 0x94, 0xb1, 0x6b,
0xf0, 0x0c, 0xfe, 0x73, 0xd5, 0x88, 0xda, 0xe2, 0x69, 0xf5, 0x1d,
0xe6, 0x6a, 0x4b, 0xa7, 0x74, 0x46, 0xee, 0x2b, 0xd1, 0xf7}},
kDomainsIndiaCCA,
},
// Not a real certificate - just for testing.
// net/data/ssl/certificates/name_constraint_*.pem
{
{{0x8e, 0x9b, 0x14, 0x9f, 0x01, 0x45, 0x4c, 0xee, 0xde, 0xfa, 0x5e,
0x73, 0x40, 0x36, 0x21, 0xba, 0xd9, 0x1f, 0xee, 0xe0, 0x3e, 0x74,
0x25, 0x6c, 0x59, 0xf4, 0x6f, 0xbf, 0x45, 0x03, 0x5f, 0x8d}},
kDomainsTest,
},
};
for (const auto& limit : kLimits) {
for (const auto& hash : public_key_hashes) {
if (hash.tag() != HASH_VALUE_SHA256)
continue;
if (memcmp(hash.data(), limit.public_key_hash.data, hash.size()) != 0)
continue;
if (dns_names.empty() && ip_addrs.empty()) {
std::vector<std::string> names;
names.push_back(common_name);
if (!CheckNameConstraints(names, limit.domains))
return true;
} else {
if (!CheckNameConstraints(dns_names, limit.domains))
return true;
}
}
}
return false;
}
// static
bool CertVerifyProc::HasTooLongValidity(const X509Certificate& cert) {
const base::Time& start = cert.valid_start();
const base::Time& expiry = cert.valid_expiry();
if (start.is_max() || start.is_null() || expiry.is_max() ||
expiry.is_null() || start > expiry) {
return true;
}
// These dates are derived from the transitions noted in Section 1.2.2
// (Relevant Dates) of the Baseline Requirements.
const base::Time time_2012_07_01 =
base::Time::UnixEpoch() + base::TimeDelta::FromSeconds(1341100800);
const base::Time time_2015_04_01 =
base::Time::UnixEpoch() + base::TimeDelta::FromSeconds(1427846400);
const base::Time time_2018_03_01 =
base::Time::UnixEpoch() + base::TimeDelta::FromSeconds(1519862400);
const base::Time time_2019_07_01 =
base::Time::UnixEpoch() + base::TimeDelta::FromSeconds(1561939200);
// Compute the maximally permissive interpretations, accounting for leap
// years.
// 10 years - two possible leap years.
constexpr base::TimeDelta kTenYears =
base::TimeDelta::FromDays((365 * 8) + (366 * 2));
// 5 years - two possible leap years (year 0/year 4 or year 1/year 5).
constexpr base::TimeDelta kSixtyMonths =
base::TimeDelta::FromDays((365 * 3) + (366 * 2));
// 39 months - one possible leap year, two at 365 days, and the longest
// monthly sequence of 31/31/30 days (June/July/August).
constexpr base::TimeDelta kThirtyNineMonths =
base::TimeDelta::FromDays(366 + 365 + 365 + 31 + 31 + 30);
base::TimeDelta validity_duration = cert.valid_expiry() - cert.valid_start();
// For certificates issued before the BRs took effect.
if (start < time_2012_07_01 &&
(validity_duration > kTenYears || expiry > time_2019_07_01)) {
return true;
}
// For certificates issued after the BR effective date of 1 July 2012: 60
// months.
if (start >= time_2012_07_01 && validity_duration > kSixtyMonths)
return true;
// For certificates issued after 1 April 2015: 39 months.
if (start >= time_2015_04_01 && validity_duration > kThirtyNineMonths)
return true;
// For certificates issued after 1 March 2018: 825 days.
if (start >= time_2018_03_01 &&
validity_duration > base::TimeDelta::FromDays(825)) {
return true;
}
return false;
}
// static
const base::Feature CertVerifyProc::kSHA1LegacyMode{
"SHA1LegacyMode", base::FEATURE_DISABLED_BY_DEFAULT};
} // namespace net