The Tor Browser: security/pkix/lib/pkixcheck.cpp@925c144e1f1f (annotated)

security/pkix/lib/pkixcheck.cpp@925c144e1f1f (annotated)

security/pkix/lib/pkixcheck.cpp

Fri, 16 Jan 2015 18:13:44 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Fri, 16 Jan 2015 18:13:44 +0100
branch: TOR_BUG_9701
changeset 14: 925c144e1f1f
permissions: -rw-r--r--

Integrate suggestion from review to improve consistency with existing code.

 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
 /* Copyright 2013 Mozilla Foundation
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 #include <limits>
 #include "pkix/pkix.h"
 #include "pkixcheck.h"
 #include "pkixder.h"
 #include "pkixutil.h"
 #include "secder.h"
 namespace mozilla { namespace pkix {
 Result
 CheckTimes(const CERTCertificate* cert, PRTime time)
 {
   PR_ASSERT(cert);
   SECCertTimeValidity validity = CERT_CheckCertValidTimes(cert, time, false);
   if (validity != secCertTimeValid) {
     return Fail(RecoverableError, SEC_ERROR_EXPIRED_CERTIFICATE);
   }
   return Success;
 }
 // 4.2.1.3. Key Usage (id-ce-keyUsage)
 // As explained in the comment in CheckKeyUsage, bit 0 is the most significant
 // bit and bit 7 is the least significant bit.
 inline uint8_t KeyUsageToBitMask(KeyUsage keyUsage)
 {
   PR_ASSERT(keyUsage != KeyUsage::noParticularKeyUsageRequired);
   return 0x80u >> static_cast<uint8_t>(keyUsage);
 }
 Result
 CheckKeyUsage(EndEntityOrCA endEntityOrCA, const SECItem* encodedKeyUsage,
               KeyUsage requiredKeyUsageIfPresent)
 {
   if (!encodedKeyUsage) {
     // TODO(bug 970196): Reject certificates that are being used to verify
     // certificate signatures unless the certificate is a trust anchor, to
     // reduce the chances of an end-entity certificate being abused as a CA
     // certificate.
     // if (endEntityOrCA == EndEntityOrCA::MustBeCA && !isTrustAnchor) {
     //   return Fail(RecoverableError, SEC_ERROR_INADEQUATE_KEY_USAGE);
     // }
     //
     // TODO: Users may configure arbitrary certificates as trust anchors, not
     // just roots. We should only allow a certificate without a key usage to be
     // used as a CA when it is self-issued and self-signed.
     return Success;
   }
   der::Input input;
   if (input.Init(encodedKeyUsage->data, encodedKeyUsage->len) != der::Success) {
     return Fail(RecoverableError, SEC_ERROR_INADEQUATE_KEY_USAGE);
   }
   der::Input value;
   if (der::ExpectTagAndGetValue(input, der::BIT_STRING, value) != der::Success) {
     return Fail(RecoverableError, SEC_ERROR_INADEQUATE_KEY_USAGE);
   }
   uint8_t numberOfPaddingBits;
   if (value.Read(numberOfPaddingBits) != der::Success) {
     return Fail(RecoverableError, SEC_ERROR_INADEQUATE_KEY_USAGE);
   }
   if (numberOfPaddingBits > 7) {
     return Fail(RecoverableError, SEC_ERROR_INADEQUATE_KEY_USAGE);
   }
   uint8_t bits;
   if (value.Read(bits) != der::Success) {
     // Reject empty bit masks.
     return Fail(RecoverableError, SEC_ERROR_INADEQUATE_KEY_USAGE);
   }
   // The most significant bit is numbered 0 (digitalSignature) and the least
   // significant bit is numbered 7 (encipherOnly), and the padding is in the
   // least significant bits of the last byte. The numbering of bits in a byte
   // is backwards from how we usually interpret them.
   //
   // For example, let's say bits is encoded in one byte with of value 0xB0 and
   // numberOfPaddingBits == 4. Then, bits is 10110000 in binary:
   //
   //      bit 0  bit 3
   //          |  |
   //          v  v
   //          10110000
   //              ^^^^
   //               |
   //               4 padding bits
   //
   // Since bits is the last byte, we have to consider the padding by ensuring
   // that the least significant 4 bits are all zero, since DER rules require
   // all padding bits to be zero. Then we have to look at the bit N bits to the
   // right of the most significant bit, where N is a value from the KeyUsage
   // enumeration.
   //
   // Let's say we're interested in the keyCertSign (5) bit. We'd need to look
   // at bit 5, which is zero, so keyCertSign is not asserted. (Since we check
   // that the padding is all zeros, it is OK to read from the padding bits.)
   //
   // Let's say we're interested in the digitalSignature (0) bit. We'd need to
   // look at the bit 0 (the most significant bit), which is set, so that means
   // digitalSignature is asserted. Similarly, keyEncipherment (2) and
   // dataEncipherment (3) are asserted.
   //
   // Note that since the KeyUsage enumeration is limited to values 0-7, we
   // only ever need to examine the first byte test for
   // requiredKeyUsageIfPresent.
   if (requiredKeyUsageIfPresent != KeyUsage::noParticularKeyUsageRequired) {
     // Check that the required key usage bit is set.
     if ((bits & KeyUsageToBitMask(requiredKeyUsageIfPresent)) == 0) {
       return Fail(RecoverableError, SEC_ERROR_INADEQUATE_KEY_USAGE);
     }
   }
   if (endEntityOrCA != EndEntityOrCA::MustBeCA) {
     // RFC 5280 says "The keyCertSign bit is asserted when the subject public
     // key is used for verifying signatures on public key certificates. If the
     // keyCertSign bit is asserted, then the cA bit in the basic constraints
     // extension (Section 4.2.1.9) MUST also be asserted."
     if ((bits & KeyUsageToBitMask(KeyUsage::keyCertSign)) != 0) {
       return Fail(RecoverableError, SEC_ERROR_INADEQUATE_KEY_USAGE);
     }
   }
   // The padding applies to the last byte, so skip to the last byte.
   while (!value.AtEnd()) {
     if (value.Read(bits) != der::Success) {
       return Fail(RecoverableError, SEC_ERROR_INADEQUATE_KEY_USAGE);
     }
   }
   // All of the padding bits must be zero, according to DER rules.
   uint8_t paddingMask = static_cast<uint8_t>((1 << numberOfPaddingBits) - 1);
   if ((bits & paddingMask) != 0) {
     return Fail(RecoverableError, SEC_ERROR_INADEQUATE_KEY_USAGE);
   }
   return Success;
 }
 // RFC5820 4.2.1.4. Certificate Policies
 //
 // "The user-initial-policy-set contains the special value any-policy if the
 // user is not concerned about certificate policy."
 Result
 CheckCertificatePolicies(BackCert& cert, EndEntityOrCA endEntityOrCA,
                          bool isTrustAnchor, SECOidTag requiredPolicy)
 {
   if (requiredPolicy == SEC_OID_X509_ANY_POLICY) {
     return Success;
   }
   // It is likely some callers will pass SEC_OID_UNKNOWN when they don't care,
   // instead of passing SEC_OID_X509_ANY_POLICY. Help them out by failing hard.
   if (requiredPolicy == SEC_OID_UNKNOWN) {
     PR_SetError(SEC_ERROR_INVALID_ARGS, 0);
     return FatalError;
   }
   // Bug 989051. Until we handle inhibitAnyPolicy we will fail close when
   // inhibitAnyPolicy extension is present and we need to evaluate certificate
   // policies.
   if (cert.encodedInhibitAnyPolicy) {
     PR_SetError(SEC_ERROR_POLICY_VALIDATION_FAILED, 0);
     return RecoverableError;
   }
   // The root CA certificate may omit the policies that it has been
   // trusted for, so we cannot require the policies to be present in those
   // certificates. Instead, the determination of which roots are trusted for
   // which policies is made by the TrustDomain's GetCertTrust method.
   if (isTrustAnchor && endEntityOrCA == MustBeCA) {
     return Success;
   }
   if (!cert.encodedCertificatePolicies) {
     PR_SetError(SEC_ERROR_POLICY_VALIDATION_FAILED, 0);
     return RecoverableError;
   }
   ScopedPtr<CERTCertificatePolicies, CERT_DestroyCertificatePoliciesExtension>
     policies(CERT_DecodeCertificatePoliciesExtension(
                 cert.encodedCertificatePolicies));
   if (!policies) {
     return MapSECStatus(SECFailure);
   }
   for (const CERTPolicyInfo* const* policyInfos = policies->policyInfos;
        *policyInfos; ++policyInfos) {
     if ((*policyInfos)->oid == requiredPolicy) {
       return Success;
     }
     // Intermediate certs are allowed to have the anyPolicy OID
     if (endEntityOrCA == MustBeCA &&
         (*policyInfos)->oid == SEC_OID_X509_ANY_POLICY) {
       return Success;
     }
   }
   PR_SetError(SEC_ERROR_POLICY_VALIDATION_FAILED, 0);
   return RecoverableError;
 }
 //  BasicConstraints ::= SEQUENCE {
 //          cA                      BOOLEAN DEFAULT FALSE,
 //          pathLenConstraint       INTEGER (0..MAX) OPTIONAL }
 der::Result
 DecodeBasicConstraints(const SECItem* encodedBasicConstraints,
                        CERTBasicConstraints& basicConstraints)
 {
   PR_ASSERT(encodedBasicConstraints);
   if (!encodedBasicConstraints) {
     return der::Fail(SEC_ERROR_INVALID_ARGS);
   }
   basicConstraints.isCA = false;
   basicConstraints.pathLenConstraint = 0;
   der::Input input;
   if (input.Init(encodedBasicConstraints->data, encodedBasicConstraints->len)
         != der::Success) {
     return der::Fail(SEC_ERROR_EXTENSION_VALUE_INVALID);
   }
   if (der::ExpectTagAndIgnoreLength(input, der::SEQUENCE) != der::Success) {
     return der::Fail(SEC_ERROR_EXTENSION_VALUE_INVALID);
   }
   bool isCA = false;
   // TODO(bug 989518): cA is by default false. According to DER, default
   // values must not be explicitly encoded in a SEQUENCE. So, if this
   // value is present and false, it is an encoding error. However, Go Daddy
   // has issued many certificates with this improper encoding, so we can't
   // enforce this yet (hence passing true for allowInvalidExplicitEncoding
   // to der::OptionalBoolean).
   if (der::OptionalBoolean(input, true, isCA) != der::Success) {
     return der::Fail(SEC_ERROR_EXTENSION_VALUE_INVALID);
   }
   basicConstraints.isCA = isCA;
   if (input.Peek(der::INTEGER)) {
     SECItem pathLenConstraintEncoded;
     if (der::Integer(input, pathLenConstraintEncoded) != der::Success) {
       return der::Fail(SEC_ERROR_EXTENSION_VALUE_INVALID);
     }
     long pathLenConstraint = DER_GetInteger(&pathLenConstraintEncoded);
     if (pathLenConstraint >= std::numeric_limits<int>::max() ||
         pathLenConstraint < 0) {
       return der::Fail(SEC_ERROR_EXTENSION_VALUE_INVALID);
     }
     basicConstraints.pathLenConstraint = static_cast<int>(pathLenConstraint);
     // TODO(bug 985025): If isCA is false, pathLenConstraint MUST NOT
     // be included (as per RFC 5280 section 4.2.1.9), but for compatibility
     // reasons, we don't check this for now.
   } else if (basicConstraints.isCA) {
     // If this is a CA but the path length is omitted, it is unlimited.
     basicConstraints.pathLenConstraint = CERT_UNLIMITED_PATH_CONSTRAINT;
   }
   if (der::End(input) != der::Success) {
     return der::Fail(SEC_ERROR_EXTENSION_VALUE_INVALID);
   }
   return der::Success;
 }
 // RFC5280 4.2.1.9. Basic Constraints (id-ce-basicConstraints)
 Result
 CheckBasicConstraints(const BackCert& cert,
                       EndEntityOrCA endEntityOrCA,
                       bool isTrustAnchor,
                       unsigned int subCACount)
 {
   CERTBasicConstraints basicConstraints;
   if (cert.encodedBasicConstraints) {
     if (DecodeBasicConstraints(cert.encodedBasicConstraints,
                                basicConstraints) != der::Success) {
       return RecoverableError;
     }
   } else {
     // Synthesize a non-CA basic constraints by default
     basicConstraints.isCA = false;
     basicConstraints.pathLenConstraint = 0;
     // "If the basic constraints extension is not present in a version 3
     //  certificate, or the extension is present but the cA boolean is not
     //  asserted, then the certified public key MUST NOT be used to verify
     //  certificate signatures."
     //
     // For compatibility, we must accept v1 trust anchors without basic
     // constraints as CAs.
     //
     // TODO: add check for self-signedness?
     if (endEntityOrCA == MustBeCA && isTrustAnchor) {
       const CERTCertificate* nssCert = cert.GetNSSCert();
       // We only allow trust anchor CA certs to omit the
       // basicConstraints extension if they are v1. v1 is encoded
       // implicitly.
       if (!nssCert->version.data && !nssCert->version.len) {
         basicConstraints.isCA = true;
         basicConstraints.pathLenConstraint = CERT_UNLIMITED_PATH_CONSTRAINT;
       }
     }
   }
   if (endEntityOrCA == MustBeEndEntity) {
     // CA certificates are not trusted as EE certs.
     if (basicConstraints.isCA) {
       // XXX: We use SEC_ERROR_CA_CERT_INVALID here so we can distinguish
       // this error from other errors, given that NSS does not have a "CA cert
       // used as end-entity" error code since it doesn't have such a
       // prohibition. We should add such an error code and stop abusing
       // SEC_ERROR_CA_CERT_INVALID this way.
       //
       // Note, in particular, that this check prevents a delegated OCSP
       // response signing certificate with the CA bit from successfully
       // validating when we check it from pkixocsp.cpp, which is a good thing.
       //
       return Fail(RecoverableError, SEC_ERROR_CA_CERT_INVALID);
     }
     return Success;
   }
   PORT_Assert(endEntityOrCA == MustBeCA);
   // End-entity certificates are not allowed to act as CA certs.
   if (!basicConstraints.isCA) {
     return Fail(RecoverableError, SEC_ERROR_CA_CERT_INVALID);
   }
   if (basicConstraints.pathLenConstraint >= 0) {
     if (subCACount >
            static_cast<unsigned int>(basicConstraints.pathLenConstraint)) {
       return Fail(RecoverableError, SEC_ERROR_PATH_LEN_CONSTRAINT_INVALID);
     }
   }
   return Success;
 }
 Result
 BackCert::GetConstrainedNames(/*out*/ const CERTGeneralName** result)
 {
   if (!constrainedNames) {
     if (!GetArena()) {
       return FatalError;
     }
     constrainedNames =
       CERT_GetConstrainedCertificateNames(nssCert, arena.get(),
                                           cnOptions == IncludeCN);
     if (!constrainedNames) {
       return MapSECStatus(SECFailure);
     }
   }
   *result = constrainedNames;
   return Success;
 }
 // 4.2.1.10. Name Constraints
 Result
 CheckNameConstraints(BackCert& cert)
 {
   static const char constraintFranceGov[] =
                                      "\x30\x5D" /* sequence len 93*/
                                      "\xA0\x5B" /* element len 91 */
                                      "\x30\x05" /* sequence len 5 */
                                      "\x82\x03" /* entry len 3 */
                                      ".fr"
                                      "\x30\x05\x82\x03" /* sequence len 5, entry len 3 */
                                      ".gp"
                                      "\x30\x05\x82\x03"
                                      ".gf"
                                      "\x30\x05\x82\x03"
                                      ".mq"
                                      "\x30\x05\x82\x03"
                                      ".re"
                                      "\x30\x05\x82\x03"
                                      ".yt"
                                      "\x30\x05\x82\x03"
                                      ".pm"
                                      "\x30\x05\x82\x03"
                                      ".bl"
                                      "\x30\x05\x82\x03"
                                      ".mf"
                                      "\x30\x05\x82\x03"
                                      ".wf"
                                      "\x30\x05\x82\x03"
                                      ".pf"
                                      "\x30\x05\x82\x03"
                                      ".nc"
                                      "\x30\x05\x82\x03"
                                      ".tf";
   /* The stringified value for the subject is:
      E=igca@sgdn.pm.gouv.fr,CN=IGC/A,OU=DCSSI,O=PM/SGDN,L=Paris,ST=France,C=FR
    */
   static const char rawANSSISubject[] =
                                  "\x30\x81\x85\x31\x0B\x30\x09\x06\x03\x55\x04"
                                  "\x06\x13\x02\x46\x52\x31\x0F\x30\x0D\x06\x03"
                                  "\x55\x04\x08\x13\x06\x46\x72\x61\x6E\x63\x65"
                                  "\x31\x0E\x30\x0C\x06\x03\x55\x04\x07\x13\x05"
                                  "\x50\x61\x72\x69\x73\x31\x10\x30\x0E\x06\x03"
                                  "\x55\x04\x0A\x13\x07\x50\x4D\x2F\x53\x47\x44"
                                  "\x4E\x31\x0E\x30\x0C\x06\x03\x55\x04\x0B\x13"
                                  "\x05\x44\x43\x53\x53\x49\x31\x0E\x30\x0C\x06"
                                  "\x03\x55\x04\x03\x13\x05\x49\x47\x43\x2F\x41"
                                  "\x31\x23\x30\x21\x06\x09\x2A\x86\x48\x86\xF7"
                                  "\x0D\x01\x09\x01\x16\x14\x69\x67\x63\x61\x40"
                                  "\x73\x67\x64\x6E\x2E\x70\x6D\x2E\x67\x6F\x75"
                                  "\x76\x2E\x66\x72";
   const SECItem ANSSI_SUBJECT = {
     siBuffer,
     reinterpret_cast<uint8_t *>(const_cast<char *>(rawANSSISubject)),
     sizeof(rawANSSISubject) - 1
   };
   const SECItem PERMIT_FRANCE_GOV_NC = {
     siBuffer,
     reinterpret_cast<uint8_t *>(const_cast<char *>(constraintFranceGov)),
     sizeof(constraintFranceGov) - 1
   };
   const SECItem* nameConstraintsToUse = cert.encodedNameConstraints;
   if (!nameConstraintsToUse) {
     if (SECITEM_ItemsAreEqual(&cert.GetNSSCert()->derSubject, &ANSSI_SUBJECT)) {
       nameConstraintsToUse = &PERMIT_FRANCE_GOV_NC;
     } else {
       return Success;
     }
   }
   PLArenaPool* arena = cert.GetArena();
   if (!arena) {
     return FatalError;
   }
   // Owned by arena
   const CERTNameConstraints* constraints =
     CERT_DecodeNameConstraintsExtension(arena, nameConstraintsToUse);
   if (!constraints) {
     return MapSECStatus(SECFailure);
   }
   for (BackCert* prev = cert.childCert; prev; prev = prev->childCert) {
     const CERTGeneralName* names = nullptr;
     Result rv = prev->GetConstrainedNames(&names);
     if (rv != Success) {
       return rv;
     }
     PORT_Assert(names);
     CERTGeneralName* currentName = const_cast<CERTGeneralName*>(names);
     do {
       if (CERT_CheckNameSpace(arena, constraints, currentName) != SECSuccess) {
         // XXX: It seems like CERT_CheckNameSpace doesn't always call
         // PR_SetError when it fails. We set the error code here, though this
         // may be papering over some fatal errors. NSS's
         // cert_VerifyCertChainOld does something similar.
         PR_SetError(SEC_ERROR_CERT_NOT_IN_NAME_SPACE, 0);
         return RecoverableError;
       }
       currentName = CERT_GetNextGeneralName(currentName);
     } while (currentName != names);
   }
   return Success;
 }
 // 4.2.1.12. Extended Key Usage (id-ce-extKeyUsage)
 // 4.2.1.12. Extended Key Usage (id-ce-extKeyUsage)
 Result
 CheckExtendedKeyUsage(EndEntityOrCA endEntityOrCA, const SECItem* encodedEKUs,
                       SECOidTag requiredEKU)
 {
   // TODO: Either do not allow anyExtendedKeyUsage to be passed as requiredEKU,
   // or require that callers pass anyExtendedKeyUsage instead of
   // SEC_OID_UNKNWON and disallow SEC_OID_UNKNWON.
   // XXX: We're using SEC_ERROR_INADEQUATE_CERT_TYPE here so that callers can
   // distinguish EKU mismatch from KU mismatch from basic constraints mismatch.
   // We should probably add a new error code that is more clear for this type
   // of problem.
   bool foundOCSPSigning = false;
   if (encodedEKUs) {
     ScopedPtr<CERTOidSequence, CERT_DestroyOidSequence>
       seq(CERT_DecodeOidSequence(encodedEKUs));
     if (!seq) {
       PR_SetError(SEC_ERROR_INADEQUATE_CERT_TYPE, 0);
       return RecoverableError;
     }
     bool found = false;
     // XXX: We allow duplicate entries.
     for (const SECItem* const* oids = seq->oids; oids && *oids; ++oids) {
       SECOidTag oidTag = SECOID_FindOIDTag(*oids);
       if (requiredEKU != SEC_OID_UNKNOWN && oidTag == requiredEKU) {
         found = true;
       } else {
         // Treat CA certs with step-up OID as also having SSL server type.
         // COMODO has issued certificates that require this behavior
         // that don't expire until June 2020!
         // TODO 982932: Limit this expection to old certificates
         if (endEntityOrCA == MustBeCA &&
             requiredEKU == SEC_OID_EXT_KEY_USAGE_SERVER_AUTH &&
             oidTag == SEC_OID_NS_KEY_USAGE_GOVT_APPROVED) {
           found = true;
         }
       }
       if (oidTag == SEC_OID_OCSP_RESPONDER) {
         foundOCSPSigning = true;
       }
     }
     // If the EKU extension was included, then the required EKU must be in the
     // list.
     if (!found) {
       PR_SetError(SEC_ERROR_INADEQUATE_CERT_TYPE, 0);
       return RecoverableError;
     }
   }
   // pkixocsp.cpp depends on the following additional checks.
   if (endEntityOrCA == MustBeEndEntity) {
     // When validating anything other than an delegated OCSP signing cert,
     // reject any cert that also claims to be an OCSP responder, because such
     // a cert does not make sense. For example, if an SSL certificate were to
     // assert id-kp-OCSPSigning then it could sign OCSP responses for itself,
     // if not for this check.
     // That said, we accept CA certificates with id-kp-OCSPSigning because
     // some CAs in Mozilla's CA program have issued such intermediate
     // certificates, and because some CAs have reported some Microsoft server
     // software wrongly requires CA certificates to have id-kp-OCSPSigning.
     // Allowing this exception does not cause any security issues because we
     // require delegated OCSP response signing certificates to be end-entity
     // certificates.
     if (foundOCSPSigning && requiredEKU != SEC_OID_OCSP_RESPONDER) {
       PR_SetError(SEC_ERROR_INADEQUATE_CERT_TYPE, 0);
       return RecoverableError;
     }
     // http://tools.ietf.org/html/rfc6960#section-4.2.2.2:
     // "OCSP signing delegation SHALL be designated by the inclusion of
     // id-kp-OCSPSigning in an extended key usage certificate extension
     // included in the OCSP response signer's certificate."
     //
     // id-kp-OCSPSigning is the only EKU that isn't implicitly assumed when the
     // EKU extension is missing from an end-entity certificate. However, any CA
     // certificate can issue a delegated OCSP response signing certificate, so
     // we can't require the EKU be explicitly included for CA certificates.
     if (!foundOCSPSigning && requiredEKU == SEC_OID_OCSP_RESPONDER) {
       PR_SetError(SEC_ERROR_INADEQUATE_CERT_TYPE, 0);
       return RecoverableError;
     }
   }
   return Success;
 }
 Result
 CheckIssuerIndependentProperties(TrustDomain& trustDomain,
                                  BackCert& cert,
                                  PRTime time,
                                  EndEntityOrCA endEntityOrCA,
                                  KeyUsage requiredKeyUsageIfPresent,
                                  SECOidTag requiredEKUIfPresent,
                                  SECOidTag requiredPolicy,
                                  unsigned int subCACount,
                 /*optional out*/ TrustDomain::TrustLevel* trustLevelOut)
 {
   Result rv;
   TrustDomain::TrustLevel trustLevel;
   rv = MapSECStatus(trustDomain.GetCertTrust(endEntityOrCA,
                                              requiredPolicy,
                                              cert.GetNSSCert(),
                                              &trustLevel));
   if (rv != Success) {
     return rv;
   }
   if (trustLevel == TrustDomain::ActivelyDistrusted) {
     PORT_SetError(SEC_ERROR_UNTRUSTED_CERT);
     return RecoverableError;
   }
   if (trustLevel != TrustDomain::TrustAnchor &&
       trustLevel != TrustDomain::InheritsTrust) {
     // The TrustDomain returned a trust level that we weren't expecting.
     PORT_SetError(PR_INVALID_STATE_ERROR);
     return FatalError;
   }
   if (trustLevelOut) {
     *trustLevelOut = trustLevel;
   }
   bool isTrustAnchor = endEntityOrCA == MustBeCA &&
                        trustLevel == TrustDomain::TrustAnchor;
   PLArenaPool* arena = cert.GetArena();
   if (!arena) {
     return FatalError;
   }
   // 4.2.1.1. Authority Key Identifier is ignored (see bug 965136).
   // 4.2.1.2. Subject Key Identifier is ignored (see bug 965136).
   // 4.2.1.3. Key Usage
   rv = CheckKeyUsage(endEntityOrCA, cert.encodedKeyUsage,
                      requiredKeyUsageIfPresent);
   if (rv != Success) {
     return rv;
   }
   // 4.2.1.4. Certificate Policies
   rv = CheckCertificatePolicies(cert, endEntityOrCA, isTrustAnchor,
                                 requiredPolicy);
   if (rv != Success) {
     return rv;
   }
   // 4.2.1.5. Policy Mappings are not supported; see the documentation about
   //          policy enforcement in pkix.h.
   // 4.2.1.6. Subject Alternative Name dealt with during name constraint
   //          checking and during name verification (CERT_VerifyCertName).
   // 4.2.1.7. Issuer Alternative Name is not something that needs checking.
   // 4.2.1.8. Subject Directory Attributes is not something that needs
   //          checking.
   // 4.2.1.9. Basic Constraints.
   rv = CheckBasicConstraints(cert, endEntityOrCA, isTrustAnchor, subCACount);
   if (rv != Success) {
     return rv;
   }
   // 4.2.1.10. Name Constraints is dealt with in during path building.
   // 4.2.1.11. Policy Constraints are implicitly supported; see the
   //           documentation about policy enforcement in pkix.h.
   // 4.2.1.12. Extended Key Usage
   rv = CheckExtendedKeyUsage(endEntityOrCA, cert.encodedExtendedKeyUsage,
                              requiredEKUIfPresent);
   if (rv != Success) {
     return rv;
   }
   // 4.2.1.13. CRL Distribution Points is not supported, though the
   //           TrustDomain's CheckRevocation method may parse it and process it
   //           on its own.
   // 4.2.1.14. Inhibit anyPolicy is implicitly supported; see the documentation
   //           about policy enforcement in pkix.h.
   // IMPORTANT: This check must come after the other checks in order for error
   // ranking to work correctly.
   rv = CheckTimes(cert.GetNSSCert(), time);
   if (rv != Success) {
     return rv;
   }
   return Success;
 }
 } } // namespace mozilla::pkix

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security/pkix/lib/pkixcheck.cpp@925c144e1f1f (annotated)

security/pkix/lib/pkixcheck.cpp