X-Git-Url: http://git.osdn.net/view?p=bytom%2Fvapor.git;a=blobdiff_plain;f=vendor%2Fgithub.com%2Fbytom%2Fcrypto%2Fsm2%2Fverify.go;fp=vendor%2Fgithub.com%2Fbytom%2Fcrypto%2Fsm2%2Fverify.go;h=ec23e4821e7751b1e7df7b28a163329819af5dc3;hp=0000000000000000000000000000000000000000;hb=8da5d90ecadf13f1510dbbc4bce05645684142a2;hpb=0bd22d212b767702bd1c99edb05d5f3a57cb572c diff --git a/vendor/github.com/bytom/crypto/sm2/verify.go b/vendor/github.com/bytom/crypto/sm2/verify.go new file mode 100644 index 00000000..ec23e482 --- /dev/null +++ b/vendor/github.com/bytom/crypto/sm2/verify.go @@ -0,0 +1,553 @@ +package sm2 + +import ( + "bytes" + "errors" + "fmt" + "net" + "runtime" + "strings" + "time" + "unicode/utf8" +) + +type InvalidReason int + +const ( + // NotAuthorizedToSign results when a certificate is signed by another + // which isn't marked as a CA certificate. + NotAuthorizedToSign InvalidReason = iota + // Expired results when a certificate has expired, based on the time + // given in the VerifyOptions. + Expired + // CANotAuthorizedForThisName results when an intermediate or root + // certificate has a name constraint which doesn't include the name + // being checked. + CANotAuthorizedForThisName + // TooManyIntermediates results when a path length constraint is + // violated. + TooManyIntermediates + // IncompatibleUsage results when the certificate's key usage indicates + // that it may only be used for a different purpose. + IncompatibleUsage + // NameMismatch results when the subject name of a parent certificate + // does not match the issuer name in the child. + NameMismatch +) + +// CertificateInvalidError results when an odd error occurs. Users of this +// library probably want to handle all these errors uniformly. +type CertificateInvalidError struct { + Cert *Certificate + Reason InvalidReason +} + +func (e CertificateInvalidError) Error() string { + switch e.Reason { + case NotAuthorizedToSign: + return "x509: certificate is not authorized to sign other certificates" + case Expired: + return "x509: certificate has expired or is not yet valid" + case CANotAuthorizedForThisName: + return "x509: a root or intermediate certificate is not authorized to sign in this domain" + case TooManyIntermediates: + return "x509: too many intermediates for path length constraint" + case IncompatibleUsage: + return "x509: certificate specifies an incompatible key usage" + case NameMismatch: + return "x509: issuer name does not match subject from issuing certificate" + } + return "x509: unknown error" +} + +// HostnameError results when the set of authorized names doesn't match the +// requested name. +type HostnameError struct { + Certificate *Certificate + Host string +} + +func (h HostnameError) Error() string { + c := h.Certificate + + var valid string + if ip := net.ParseIP(h.Host); ip != nil { + // Trying to validate an IP + if len(c.IPAddresses) == 0 { + return "x509: cannot validate certificate for " + h.Host + " because it doesn't contain any IP SANs" + } + for _, san := range c.IPAddresses { + if len(valid) > 0 { + valid += ", " + } + valid += san.String() + } + } else { + if len(c.DNSNames) > 0 { + valid = strings.Join(c.DNSNames, ", ") + } else { + valid = c.Subject.CommonName + } + } + + if len(valid) == 0 { + return "x509: certificate is not valid for any names, but wanted to match " + h.Host + } + return "x509: certificate is valid for " + valid + ", not " + h.Host +} + +// UnknownAuthorityError results when the certificate issuer is unknown +type UnknownAuthorityError struct { + Cert *Certificate + // hintErr contains an error that may be helpful in determining why an + // authority wasn't found. + hintErr error + // hintCert contains a possible authority certificate that was rejected + // because of the error in hintErr. + hintCert *Certificate +} + +func (e UnknownAuthorityError) Error() string { + s := "x509: certificate signed by unknown authority" + if e.hintErr != nil { + certName := e.hintCert.Subject.CommonName + if len(certName) == 0 { + if len(e.hintCert.Subject.Organization) > 0 { + certName = e.hintCert.Subject.Organization[0] + } else { + certName = "serial:" + e.hintCert.SerialNumber.String() + } + } + s += fmt.Sprintf(" (possibly because of %q while trying to verify candidate authority certificate %q)", e.hintErr, certName) + } + return s +} + +// SystemRootsError results when we fail to load the system root certificates. +type SystemRootsError struct { + Err error +} + +func (se SystemRootsError) Error() string { + msg := "x509: failed to load system roots and no roots provided" + if se.Err != nil { + return msg + "; " + se.Err.Error() + } + return msg +} + +// errNotParsed is returned when a certificate without ASN.1 contents is +// verified. Platform-specific verification needs the ASN.1 contents. +var errNotParsed = errors.New("x509: missing ASN.1 contents; use ParseCertificate") + +// VerifyOptions contains parameters for Certificate.Verify. It's a structure +// because other PKIX verification APIs have ended up needing many options. +type VerifyOptions struct { + DNSName string + Intermediates *CertPool + Roots *CertPool // if nil, the system roots are used + CurrentTime time.Time // if zero, the current time is used + // KeyUsage specifies which Extended Key Usage values are acceptable. + // An empty list means ExtKeyUsageServerAuth. Key usage is considered a + // constraint down the chain which mirrors Windows CryptoAPI behavior, + // but not the spec. To accept any key usage, include ExtKeyUsageAny. + KeyUsages []ExtKeyUsage +} + +const ( + leafCertificate = iota + intermediateCertificate + rootCertificate +) + +func matchNameConstraint(domain, constraint string) bool { + // The meaning of zero length constraints is not specified, but this + // code follows NSS and accepts them as valid for everything. + if len(constraint) == 0 { + return true + } + + if len(domain) < len(constraint) { + return false + } + + prefixLen := len(domain) - len(constraint) + if !strings.EqualFold(domain[prefixLen:], constraint) { + return false + } + + if prefixLen == 0 { + return true + } + + isSubdomain := domain[prefixLen-1] == '.' + constraintHasLeadingDot := constraint[0] == '.' + return isSubdomain != constraintHasLeadingDot +} + +// isValid performs validity checks on the c. +func (c *Certificate) isValid(certType int, currentChain []*Certificate, opts *VerifyOptions) error { + if len(currentChain) > 0 { + child := currentChain[len(currentChain)-1] + if !bytes.Equal(child.RawIssuer, c.RawSubject) { + return CertificateInvalidError{c, NameMismatch} + } + } + now := opts.CurrentTime + if now.IsZero() { + now = time.Now() + } + if now.Before(c.NotBefore) || now.After(c.NotAfter) { + return CertificateInvalidError{c, Expired} + } + if len(c.PermittedDNSDomains) > 0 { + ok := false + for _, constraint := range c.PermittedDNSDomains { + ok = matchNameConstraint(opts.DNSName, constraint) + if ok { + break + } + } + + if !ok { + return CertificateInvalidError{c, CANotAuthorizedForThisName} + } + } + + // KeyUsage status flags are ignored. From Engineering Security, Peter + // Gutmann: A European government CA marked its signing certificates as + // being valid for encryption only, but no-one noticed. Another + // European CA marked its signature keys as not being valid for + // signatures. A different CA marked its own trusted root certificate + // as being invalid for certificate signing. Another national CA + // distributed a certificate to be used to encrypt data for the + // country’s tax authority that was marked as only being usable for + // digital signatures but not for encryption. Yet another CA reversed + // the order of the bit flags in the keyUsage due to confusion over + // encoding endianness, essentially setting a random keyUsage in + // certificates that it issued. Another CA created a self-invalidating + // certificate by adding a certificate policy statement stipulating + // that the certificate had to be used strictly as specified in the + // keyUsage, and a keyUsage containing a flag indicating that the RSA + // encryption key could only be used for Diffie-Hellman key agreement. + + if certType == intermediateCertificate && (!c.BasicConstraintsValid || !c.IsCA) { + return CertificateInvalidError{c, NotAuthorizedToSign} + } + + if c.BasicConstraintsValid && c.MaxPathLen >= 0 { + numIntermediates := len(currentChain) - 1 + if numIntermediates > c.MaxPathLen { + return CertificateInvalidError{c, TooManyIntermediates} + } + } + + return nil +} + +// Verify attempts to verify c by building one or more chains from c to a +// certificate in opts.Roots, using certificates in opts.Intermediates if +// needed. If successful, it returns one or more chains where the first +// element of the chain is c and the last element is from opts.Roots. +// +// If opts.Roots is nil and system roots are unavailable the returned error +// will be of type SystemRootsError. +// +// WARNING: this doesn't do any revocation checking. +func (c *Certificate) Verify(opts VerifyOptions) (chains [][]*Certificate, err error) { + // Platform-specific verification needs the ASN.1 contents so + // this makes the behavior consistent across platforms. + if len(c.Raw) == 0 { + return nil, errNotParsed + } + if opts.Intermediates != nil { + for _, intermediate := range opts.Intermediates.certs { + if len(intermediate.Raw) == 0 { + return nil, errNotParsed + } + } + } + + // Use Windows's own verification and chain building. + if opts.Roots == nil && runtime.GOOS == "windows" { + return c.systemVerify(&opts) + } + + if len(c.UnhandledCriticalExtensions) > 0 { + return nil, UnhandledCriticalExtension{} + } + + if opts.Roots == nil { + opts.Roots = systemRootsPool() + if opts.Roots == nil { + return nil, SystemRootsError{systemRootsErr} + } + } + + err = c.isValid(leafCertificate, nil, &opts) + if err != nil { + return + } + + if len(opts.DNSName) > 0 { + err = c.VerifyHostname(opts.DNSName) + if err != nil { + return + } + } + + var candidateChains [][]*Certificate + if opts.Roots.contains(c) { + candidateChains = append(candidateChains, []*Certificate{c}) + } else { + if candidateChains, err = c.buildChains(make(map[int][][]*Certificate), []*Certificate{c}, &opts); err != nil { + return nil, err + } + } + + keyUsages := opts.KeyUsages + if len(keyUsages) == 0 { + keyUsages = []ExtKeyUsage{ExtKeyUsageServerAuth} + } + + // If any key usage is acceptable then we're done. + for _, usage := range keyUsages { + if usage == ExtKeyUsageAny { + chains = candidateChains + return + } + } + + for _, candidate := range candidateChains { + if checkChainForKeyUsage(candidate, keyUsages) { + chains = append(chains, candidate) + } + } + + if len(chains) == 0 { + err = CertificateInvalidError{c, IncompatibleUsage} + } + + return +} + +func appendToFreshChain(chain []*Certificate, cert *Certificate) []*Certificate { + n := make([]*Certificate, len(chain)+1) + copy(n, chain) + n[len(chain)] = cert + return n +} + +func (c *Certificate) buildChains(cache map[int][][]*Certificate, currentChain []*Certificate, opts *VerifyOptions) (chains [][]*Certificate, err error) { + possibleRoots, failedRoot, rootErr := opts.Roots.findVerifiedParents(c) +nextRoot: + for _, rootNum := range possibleRoots { + root := opts.Roots.certs[rootNum] + + for _, cert := range currentChain { + if cert.Equal(root) { + continue nextRoot + } + } + + err = root.isValid(rootCertificate, currentChain, opts) + if err != nil { + continue + } + chains = append(chains, appendToFreshChain(currentChain, root)) + } + + possibleIntermediates, failedIntermediate, intermediateErr := opts.Intermediates.findVerifiedParents(c) +nextIntermediate: + for _, intermediateNum := range possibleIntermediates { + intermediate := opts.Intermediates.certs[intermediateNum] + for _, cert := range currentChain { + if cert.Equal(intermediate) { + continue nextIntermediate + } + } + err = intermediate.isValid(intermediateCertificate, currentChain, opts) + if err != nil { + continue + } + var childChains [][]*Certificate + childChains, ok := cache[intermediateNum] + if !ok { + childChains, err = intermediate.buildChains(cache, appendToFreshChain(currentChain, intermediate), opts) + cache[intermediateNum] = childChains + } + chains = append(chains, childChains...) + } + + if len(chains) > 0 { + err = nil + } + + if len(chains) == 0 && err == nil { + hintErr := rootErr + hintCert := failedRoot + if hintErr == nil { + hintErr = intermediateErr + hintCert = failedIntermediate + } + err = UnknownAuthorityError{c, hintErr, hintCert} + } + + return +} + +func matchHostnames(pattern, host string) bool { + host = strings.TrimSuffix(host, ".") + pattern = strings.TrimSuffix(pattern, ".") + + if len(pattern) == 0 || len(host) == 0 { + return false + } + + patternParts := strings.Split(pattern, ".") + hostParts := strings.Split(host, ".") + + if len(patternParts) != len(hostParts) { + return false + } + + for i, patternPart := range patternParts { + if i == 0 && patternPart == "*" { + continue + } + if patternPart != hostParts[i] { + return false + } + } + + return true +} + +// toLowerCaseASCII returns a lower-case version of in. See RFC 6125 6.4.1. We use +// an explicitly ASCII function to avoid any sharp corners resulting from +// performing Unicode operations on DNS labels. +func toLowerCaseASCII(in string) string { + // If the string is already lower-case then there's nothing to do. + isAlreadyLowerCase := true + for _, c := range in { + if c == utf8.RuneError { + // If we get a UTF-8 error then there might be + // upper-case ASCII bytes in the invalid sequence. + isAlreadyLowerCase = false + break + } + if 'A' <= c && c <= 'Z' { + isAlreadyLowerCase = false + break + } + } + + if isAlreadyLowerCase { + return in + } + + out := []byte(in) + for i, c := range out { + if 'A' <= c && c <= 'Z' { + out[i] += 'a' - 'A' + } + } + return string(out) +} + +// VerifyHostname returns nil if c is a valid certificate for the named host. +// Otherwise it returns an error describing the mismatch. +func (c *Certificate) VerifyHostname(h string) error { + // IP addresses may be written in [ ]. + candidateIP := h + if len(h) >= 3 && h[0] == '[' && h[len(h)-1] == ']' { + candidateIP = h[1 : len(h)-1] + } + if ip := net.ParseIP(candidateIP); ip != nil { + // We only match IP addresses against IP SANs. + // https://tools.ietf.org/html/rfc6125#appendix-B.2 + for _, candidate := range c.IPAddresses { + if ip.Equal(candidate) { + return nil + } + } + return HostnameError{c, candidateIP} + } + + lowered := toLowerCaseASCII(h) + + if len(c.DNSNames) > 0 { + for _, match := range c.DNSNames { + if matchHostnames(toLowerCaseASCII(match), lowered) { + return nil + } + } + // If Subject Alt Name is given, we ignore the common name. + } else if matchHostnames(toLowerCaseASCII(c.Subject.CommonName), lowered) { + return nil + } + + return HostnameError{c, h} +} + +func checkChainForKeyUsage(chain []*Certificate, keyUsages []ExtKeyUsage) bool { + usages := make([]ExtKeyUsage, len(keyUsages)) + copy(usages, keyUsages) + + if len(chain) == 0 { + return false + } + + usagesRemaining := len(usages) + + // We walk down the list and cross out any usages that aren't supported + // by each certificate. If we cross out all the usages, then the chain + // is unacceptable. + +NextCert: + for i := len(chain) - 1; i >= 0; i-- { + cert := chain[i] + if len(cert.ExtKeyUsage) == 0 && len(cert.UnknownExtKeyUsage) == 0 { + // The certificate doesn't have any extended key usage specified. + continue + } + + for _, usage := range cert.ExtKeyUsage { + if usage == ExtKeyUsageAny { + // The certificate is explicitly good for any usage. + continue NextCert + } + } + + const invalidUsage ExtKeyUsage = -1 + + NextRequestedUsage: + for i, requestedUsage := range usages { + if requestedUsage == invalidUsage { + continue + } + + for _, usage := range cert.ExtKeyUsage { + if requestedUsage == usage { + continue NextRequestedUsage + } else if requestedUsage == ExtKeyUsageServerAuth && + (usage == ExtKeyUsageNetscapeServerGatedCrypto || + usage == ExtKeyUsageMicrosoftServerGatedCrypto) { + // In order to support COMODO + // certificate chains, we have to + // accept Netscape or Microsoft SGC + // usages as equal to ServerAuth. + continue NextRequestedUsage + } + } + + usages[i] = invalidUsage + usagesRemaining-- + if usagesRemaining == 0 { + return false + } + } + } + + return true +}