X-Git-Url: http://git.osdn.net/view?p=bytom%2Fvapor.git;a=blobdiff_plain;f=crypto%2Fsm2%2Fverify.go;fp=crypto%2Fsm2%2Fverify.go;h=0000000000000000000000000000000000000000;hp=ec23e4821e7751b1e7df7b28a163329819af5dc3;hb=cb120a52d80aaf7c52f101644b5aa2f521588382;hpb=4e7f502753546efa47d58ab770a5c275e7b41c77 diff --git a/crypto/sm2/verify.go b/crypto/sm2/verify.go deleted file mode 100644 index ec23e482..00000000 --- a/crypto/sm2/verify.go +++ /dev/null @@ -1,553 +0,0 @@ -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 -}