| // Copyright (c) 2016 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_ios.h" |
| |
| #include <CommonCrypto/CommonDigest.h> |
| |
| #include "base/logging.h" |
| #include "base/mac/scoped_cftyperef.h" |
| #include "crypto/sha2.h" |
| #include "net/base/net_errors.h" |
| #include "net/cert/asn1_util.h" |
| #include "net/cert/cert_verify_result.h" |
| #include "net/cert/test_root_certs.h" |
| #include "net/cert/x509_certificate.h" |
| #include "net/cert/x509_util_ios.h" |
| #include "net/cert/x509_util_ios_and_mac.h" |
| |
| using base::ScopedCFTypeRef; |
| |
| namespace net { |
| |
| namespace { |
| |
| int NetErrorFromOSStatus(OSStatus status) { |
| switch (status) { |
| case noErr: |
| return OK; |
| case errSecNotAvailable: |
| return ERR_NOT_IMPLEMENTED; |
| case errSecAuthFailed: |
| return ERR_ACCESS_DENIED; |
| default: |
| return ERR_FAILED; |
| } |
| } |
| |
| // Creates a series of SecPolicyRefs to be added to a SecTrustRef used to |
| // validate a certificate for an SSL server. |hostname| contains the name of |
| // the SSL server that the certificate should be verified against. If |
| // successful, returns noErr, and stores the resultant array of SecPolicyRefs |
| // in |policies|. |
| OSStatus CreateTrustPolicies(ScopedCFTypeRef<CFArrayRef>* policies) { |
| ScopedCFTypeRef<CFMutableArrayRef> local_policies( |
| CFArrayCreateMutable(kCFAllocatorDefault, 0, &kCFTypeArrayCallBacks)); |
| if (!local_policies) |
| return errSecAllocate; |
| |
| SecPolicyRef ssl_policy = SecPolicyCreateBasicX509(); |
| CFArrayAppendValue(local_policies, ssl_policy); |
| CFRelease(ssl_policy); |
| ssl_policy = SecPolicyCreateSSL(true, nullptr); |
| CFArrayAppendValue(local_policies, ssl_policy); |
| CFRelease(ssl_policy); |
| |
| policies->reset(local_policies.release()); |
| return noErr; |
| } |
| |
| // Builds and evaluates a SecTrustRef for the certificate chain contained |
| // in |cert_array|, using the verification policies in |trust_policies|. On |
| // success, returns OK, and updates |trust_ref| and |trust_result|. On failure, |
| // no output parameters are modified. |
| // |
| // Note: An OK return does not mean that |cert_array| is trusted, merely that |
| // verification was performed successfully. |
| int BuildAndEvaluateSecTrustRef(CFArrayRef cert_array, |
| CFArrayRef trust_policies, |
| ScopedCFTypeRef<SecTrustRef>* trust_ref, |
| ScopedCFTypeRef<CFArrayRef>* verified_chain, |
| SecTrustResultType* trust_result) { |
| SecTrustRef tmp_trust = nullptr; |
| OSStatus status = |
| SecTrustCreateWithCertificates(cert_array, trust_policies, &tmp_trust); |
| if (status) |
| return NetErrorFromOSStatus(status); |
| ScopedCFTypeRef<SecTrustRef> scoped_tmp_trust(tmp_trust); |
| |
| if (TestRootCerts::HasInstance()) { |
| status = TestRootCerts::GetInstance()->FixupSecTrustRef(tmp_trust); |
| if (status) |
| return NetErrorFromOSStatus(status); |
| } |
| |
| SecTrustResultType tmp_trust_result; |
| status = SecTrustEvaluate(tmp_trust, &tmp_trust_result); |
| if (status) |
| return NetErrorFromOSStatus(status); |
| |
| ScopedCFTypeRef<CFMutableArrayRef> tmp_verified_chain( |
| CFArrayCreateMutable(kCFAllocatorDefault, 0, &kCFTypeArrayCallBacks)); |
| const CFIndex chain_length = SecTrustGetCertificateCount(tmp_trust); |
| for (CFIndex i = 0; i < chain_length; ++i) { |
| SecCertificateRef chain_cert = SecTrustGetCertificateAtIndex(tmp_trust, i); |
| CFArrayAppendValue(tmp_verified_chain, chain_cert); |
| } |
| |
| trust_ref->swap(scoped_tmp_trust); |
| *trust_result = tmp_trust_result; |
| verified_chain->reset(tmp_verified_chain.release()); |
| return OK; |
| } |
| |
| void GetCertChainInfo(CFArrayRef cert_chain, CertVerifyResult* verify_result) { |
| DCHECK_LT(0, CFArrayGetCount(cert_chain)); |
| |
| SecCertificateRef verified_cert = nullptr; |
| std::vector<SecCertificateRef> verified_chain; |
| for (CFIndex i = 0, count = CFArrayGetCount(cert_chain); i < count; ++i) { |
| SecCertificateRef chain_cert = reinterpret_cast<SecCertificateRef>( |
| const_cast<void*>(CFArrayGetValueAtIndex(cert_chain, i))); |
| if (i == 0) { |
| verified_cert = chain_cert; |
| } else { |
| verified_chain.push_back(chain_cert); |
| } |
| |
| base::ScopedCFTypeRef<CFDataRef> der_data( |
| SecCertificateCopyData(chain_cert)); |
| if (!der_data) { |
| verify_result->cert_status |= CERT_STATUS_INVALID; |
| return; |
| } |
| |
| base::StringPiece spki_bytes; |
| if (!asn1::ExtractSPKIFromDERCert( |
| base::StringPiece( |
| reinterpret_cast<const char*>(CFDataGetBytePtr(der_data)), |
| CFDataGetLength(der_data)), |
| &spki_bytes)) { |
| verify_result->cert_status |= CERT_STATUS_INVALID; |
| return; |
| } |
| |
| HashValue sha256(HASH_VALUE_SHA256); |
| CC_SHA256(spki_bytes.data(), spki_bytes.size(), sha256.data()); |
| verify_result->public_key_hashes.push_back(sha256); |
| |
| // Ignore the signature algorithm for the trust anchor. |
| if ((verify_result->cert_status & CERT_STATUS_AUTHORITY_INVALID) == 0 && |
| i == count - 1) { |
| continue; |
| } |
| } |
| if (!verified_cert) { |
| NOTREACHED(); |
| verify_result->cert_status |= CERT_STATUS_INVALID; |
| return; |
| } |
| |
| scoped_refptr<X509Certificate> verified_cert_with_chain = |
| x509_util::CreateX509CertificateFromSecCertificate(verified_cert, |
| verified_chain); |
| if (verified_cert_with_chain) |
| verify_result->verified_cert = std::move(verified_cert_with_chain); |
| else |
| verify_result->cert_status |= CERT_STATUS_INVALID; |
| } |
| |
| } // namespace |
| |
| CertVerifyProcIOS::CertVerifyProcIOS() {} |
| |
| // The iOS APIs don't expose an API-stable set of reasons for certificate |
| // validation failures. However, internally, the reason is tracked, and it's |
| // converted to user-facing localized strings. |
| // |
| // In the absence of a consistent API, convert the English strings to their |
| // localized counterpart, and then compare that with the error properties. If |
| // they're equal, it's a strong sign that this was the cause for the error. |
| // While this will break if/when iOS changes the contents of these strings, |
| // it's sufficient enough for now. |
| // |
| // TODO(rsleevi): https://crbug.com/601915 - Use a less brittle solution when |
| // possible. |
| // static |
| CertStatus CertVerifyProcIOS::GetCertFailureStatusFromTrust(SecTrustRef trust) { |
| CertStatus reason = 0; |
| |
| base::ScopedCFTypeRef<CFArrayRef> properties(SecTrustCopyProperties(trust)); |
| if (!properties) |
| return CERT_STATUS_INVALID; |
| |
| const CFIndex properties_length = CFArrayGetCount(properties); |
| if (properties_length == 0) |
| return CERT_STATUS_INVALID; |
| |
| CFBundleRef bundle = |
| CFBundleGetBundleWithIdentifier(CFSTR("com.apple.Security")); |
| CFStringRef date_string = |
| CFSTR("One or more certificates have expired or are not valid yet."); |
| ScopedCFTypeRef<CFStringRef> date_error(CFBundleCopyLocalizedString( |
| bundle, date_string, date_string, CFSTR("SecCertificate"))); |
| CFStringRef trust_string = CFSTR("Root certificate is not trusted."); |
| ScopedCFTypeRef<CFStringRef> trust_error(CFBundleCopyLocalizedString( |
| bundle, trust_string, trust_string, CFSTR("SecCertificate"))); |
| CFStringRef weak_string = |
| CFSTR("One or more certificates is using a weak key size."); |
| ScopedCFTypeRef<CFStringRef> weak_error(CFBundleCopyLocalizedString( |
| bundle, weak_string, weak_string, CFSTR("SecCertificate"))); |
| CFStringRef hostname_mismatch_string = CFSTR("Hostname mismatch."); |
| ScopedCFTypeRef<CFStringRef> hostname_mismatch_error( |
| CFBundleCopyLocalizedString(bundle, hostname_mismatch_string, |
| hostname_mismatch_string, |
| CFSTR("SecCertificate"))); |
| |
| for (CFIndex i = 0; i < properties_length; ++i) { |
| CFDictionaryRef dict = reinterpret_cast<CFDictionaryRef>( |
| const_cast<void*>(CFArrayGetValueAtIndex(properties, i))); |
| CFStringRef error = reinterpret_cast<CFStringRef>( |
| const_cast<void*>(CFDictionaryGetValue(dict, CFSTR("value")))); |
| |
| if (CFEqual(error, date_error)) { |
| reason |= CERT_STATUS_DATE_INVALID; |
| } else if (CFEqual(error, trust_error)) { |
| reason |= CERT_STATUS_AUTHORITY_INVALID; |
| } else if (CFEqual(error, weak_error)) { |
| reason |= CERT_STATUS_WEAK_KEY; |
| } else if (CFEqual(error, hostname_mismatch_error)) { |
| reason |= CERT_STATUS_COMMON_NAME_INVALID; |
| } else { |
| reason |= CERT_STATUS_INVALID; |
| } |
| } |
| |
| return reason; |
| } |
| |
| bool CertVerifyProcIOS::SupportsAdditionalTrustAnchors() const { |
| return false; |
| } |
| |
| bool CertVerifyProcIOS::SupportsOCSPStapling() const { |
| return false; |
| } |
| |
| CertVerifyProcIOS::~CertVerifyProcIOS() = default; |
| |
| int CertVerifyProcIOS::VerifyInternal( |
| X509Certificate* cert, |
| const std::string& hostname, |
| const std::string& ocsp_response, |
| int flags, |
| CRLSet* crl_set, |
| const CertificateList& additional_trust_anchors, |
| CertVerifyResult* verify_result) { |
| ScopedCFTypeRef<CFArrayRef> trust_policies; |
| OSStatus status = CreateTrustPolicies(&trust_policies); |
| if (status) |
| return NetErrorFromOSStatus(status); |
| |
| ScopedCFTypeRef<CFMutableArrayRef> cert_array( |
| x509_util::CreateSecCertificateArrayForX509Certificate( |
| cert, x509_util::InvalidIntermediateBehavior::kIgnore)); |
| if (!cert_array) { |
| verify_result->cert_status |= CERT_STATUS_INVALID; |
| return ERR_CERT_INVALID; |
| } |
| |
| ScopedCFTypeRef<SecTrustRef> trust_ref; |
| SecTrustResultType trust_result = kSecTrustResultDeny; |
| ScopedCFTypeRef<CFArrayRef> final_chain; |
| |
| status = BuildAndEvaluateSecTrustRef(cert_array, trust_policies, &trust_ref, |
| &final_chain, &trust_result); |
| if (status) |
| return NetErrorFromOSStatus(status); |
| |
| if (CFArrayGetCount(final_chain) == 0) |
| return ERR_FAILED; |
| |
| // TODO(sleevi): Support CRLSet revocation. |
| switch (trust_result) { |
| case kSecTrustResultUnspecified: |
| case kSecTrustResultProceed: |
| break; |
| case kSecTrustResultDeny: |
| verify_result->cert_status |= CERT_STATUS_AUTHORITY_INVALID; |
| break; |
| default: |
| verify_result->cert_status |= GetCertFailureStatusFromTrust(trust_ref); |
| } |
| |
| GetCertChainInfo(final_chain, verify_result); |
| |
| // iOS lacks the ability to distinguish built-in versus non-built-in roots, |
| // so opt to 'fail open' of any restrictive policies that apply to built-in |
| // roots. |
| verify_result->is_issued_by_known_root = false; |
| |
| if (IsCertStatusError(verify_result->cert_status)) |
| return MapCertStatusToNetError(verify_result->cert_status); |
| |
| return OK; |
| } |
| |
| } // namespace net |