Result
BackCert::Init()
{
Result rv;
// Certificate ::= SEQUENCE {
// tbsCertificate TBSCertificate,
// signatureAlgorithm AlgorithmIdentifier,
// signatureValue BIT STRING }
Reader tbsCertificate;
// The scope of |input| and |certificate| are limited to this block so we
// don't accidentally confuse them for tbsCertificate later.
{
Reader certificate;
rv = der::ExpectTagAndGetValueAtEnd(der, der::SEQUENCE, certificate);
if (rv != Success) {
return rv;
}
rv = der::SignedData(certificate, tbsCertificate, signedData);
if (rv != Success) {
return rv;
}
rv = der::End(certificate);
if (rv != Success) {
return rv;
}
}
// TBSCertificate ::= SEQUENCE {
// version [0] EXPLICIT Version DEFAULT v1,
// serialNumber CertificateSerialNumber,
// signature AlgorithmIdentifier,
// issuer Name,
// validity Validity,
// subject Name,
// subjectPublicKeyInfo SubjectPublicKeyInfo,
// issuerUniqueID [1] IMPLICIT UniqueIdentifier OPTIONAL,
// -- If present, version MUST be v2 or v3
// subjectUniqueID [2] IMPLICIT UniqueIdentifier OPTIONAL,
// -- If present, version MUST be v2 or v3
// extensions [3] EXPLICIT Extensions OPTIONAL
// -- If present, version MUST be v3
// }
rv = der::OptionalVersion(tbsCertificate, version);
if (rv != Success) {
return rv;
}
rv = der::CertificateSerialNumber(tbsCertificate, serialNumber);
if (rv != Success) {
return rv;
}
rv = der::ExpectTagAndGetValue(tbsCertificate, der::SEQUENCE, signature);
if (rv != Success) {
return rv;
}
rv = der::ExpectTagAndGetTLV(tbsCertificate, der::SEQUENCE, issuer);
if (rv != Success) {
return rv;
}
rv = der::ExpectTagAndGetValue(tbsCertificate, der::SEQUENCE, validity);
if (rv != Success) {
return rv;
}
// TODO(bug XXXXXXX): We rely on the the caller of mozilla::pkix to validate
// that the name is syntactically valid, if they care. In Gecko we do this
// implicitly by parsing the certificate into a CERTCertificate object.
// Instead of relying on the caller to do this, we should do it ourselves.
rv = der::ExpectTagAndGetTLV(tbsCertificate, der::SEQUENCE, subject);
if (rv != Success) {
return rv;
}
rv = der::ExpectTagAndGetTLV(tbsCertificate, der::SEQUENCE,
subjectPublicKeyInfo);
if (rv != Success) {
return rv;
}
static const uint8_t CSC = der::CONTEXT_SPECIFIC | der::CONSTRUCTED;
// According to RFC 5280, all fields below this line are forbidden for
// certificate versions less than v3. However, for compatibility reasons,
// we parse v1/v2 certificates in the same way as v3 certificates. So if
// these fields appear in a v1 certificate, they will be used.
// Ignore issuerUniqueID if present.
if (tbsCertificate.Peek(CSC | 1)) {
rv = der::ExpectTagAndSkipValue(tbsCertificate, CSC | 1);
if (rv != Success) {
return rv;
}
}
// Ignore subjectUniqueID if present.
if (tbsCertificate.Peek(CSC | 2)) {
rv = der::ExpectTagAndSkipValue(tbsCertificate, CSC | 2);
if (rv != Success) {
return rv;
}
}
rv = der::OptionalExtensions(
tbsCertificate, CSC | 3,
[this](Reader& extnID, const Input& extnValue, bool critical,
/*out*/ bool& understood) {
return RememberExtension(extnID, extnValue, critical, understood);
});
if (rv != Success) {
return rv;
}
// The Netscape Certificate Type extension is an obsolete
// Netscape-proprietary mechanism that we ignore in favor of the standard
// extensions. However, some CAs have issued certificates with the Netscape
// Cert Type extension marked critical. Thus, for compatibility reasons, we
// "understand" this extension by ignoring it when it is not critical, and
// by ensuring that the equivalent standardized extensions are present when
// it is marked critical, based on the assumption that the information in
// the Netscape Cert Type extension is consistent with the information in
// the standard extensions.
//
// Here is a mapping between the Netscape Cert Type extension and the
// standard extensions:
//
// Netscape Cert Type | BasicConstraints.cA | Extended Key Usage
// --------------------+-----------------------+----------------------
// SSL Server | false | id_kp_serverAuth
// SSL Client | false | id_kp_clientAuth
// S/MIME Client | false | id_kp_emailProtection
// Object Signing | false | id_kp_codeSigning
// SSL Server CA | true | id_pk_serverAuth
// SSL Client CA | true | id_kp_clientAuth
// S/MIME CA | true | id_kp_emailProtection
// Object Signing CA | true | id_kp_codeSigning
if (criticalNetscapeCertificateType.GetLength() > 0 &&
(basicConstraints.GetLength() == 0 || extKeyUsage.GetLength() == 0)) {
return Result::ERROR_UNKNOWN_CRITICAL_EXTENSION;
}
return der::End(tbsCertificate);
}
void CombinedEventDelta::RememberExtensions(const SmartPointer<ExtensionPoint>& extensionPoint,
const QList<int>& exts)
{
for (int i = 0; i < exts.size(); ++i)
RememberExtension(extensionPoint, exts[i]);
}
