Exemple #1
0
func (crtkit *CertKit) GenerateServer(subject pkix.Name, host, email string, NotBefore ...time.Time) error {
	var e error
	var derBytes []byte
	var notBefore time.Time

	priv, err := rsa.GenerateKey(rand.Reader, 2048)
	if err != nil {
		return errors.New(fmt.Sprintf("failed to generate private key: %s", err))
	}

	if len(NotBefore) > 0 {
		notBefore = NotBefore[0]
	} else {
		notBefore = time.Now()
	}
	serialNumber, err := rand.Int(rand.Reader, new(big.Int).Lsh(big.NewInt(1), 128))
	if err != nil {
		return errors.New(fmt.Sprintf("failed to generate serial number: %s", err))
	}

	if host == "" {
		host, _ = os.Hostname()
	}

	Goose.Generator.Logf(6, "Certificate authority used: %#v", crtkit.CACert)

	template := x509.Certificate{
		SerialNumber:          serialNumber,
		Subject:               subject,
		IsCA:                  false,
		NotBefore:             notBefore,
		NotAfter:              notBefore.Add(365 * 24 * time.Hour),
		DNSNames:              []string{host, strings.Split(host, ".")[0]},
		AuthorityKeyId:        crtkit.CACert.SubjectKeyId,
		KeyUsage:              x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature | x509.KeyUsageContentCommitment,
		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth, x509.ExtKeyUsageClientAuth},
		BasicConstraintsValid: true,
	}

	Goose.Generator.Logf(4, "X509 Template: %#v", template)

	if crtkit.CACert.CRLDistributionPoints != nil {
		template.CRLDistributionPoints = crtkit.CACert.CRLDistributionPoints
	} else {
		Goose.Generator.Logf(1, "Certificate authority without CRL distribution points")
	}

	crtkit.ServerKey = priv
	crtkit.ServerCert = &template
	derBytes, e = x509.CreateCertificate(rand.Reader, &template, crtkit.CACert, &priv.PublicKey, crtkit.CAKey)
	if e != nil {
		return errors.New(fmt.Sprintf("Failed to create certificate: %s", e))
	}
	Goose.Generator.Logf(4, "DER Certificate: %s", derBytes)
	crtkit.ServerCertPem = pem.EncodeToMemory(&pem.Block{Type: "CERTIFICATE", Bytes: derBytes})
	crtkit.ServerKeyPem = pem.EncodeToMemory(&pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(priv)})
	Goose.Generator.Logf(4, "PEM Certificate: %s", crtkit.ServerCertPem)

	return nil
}
Exemple #2
0
func (s *Signer) sign(template *x509.Certificate, profile *config.SigningProfile) (cert []byte, err error) {
	var distPoints = template.CRLDistributionPoints
	err = signer.FillTemplate(template, s.policy.Default, profile)
	if distPoints != nil && len(distPoints) > 0 {
		template.CRLDistributionPoints = distPoints
	}
	if err != nil {
		return
	}

	var initRoot bool
	if s.ca == nil {
		if !template.IsCA {
			err = cferr.New(cferr.PolicyError, cferr.InvalidRequest)
			return
		}
		template.DNSNames = nil
		template.EmailAddresses = nil
		s.ca = template
		initRoot = true
	} else if template.IsCA {
		template.DNSNames = nil
		template.EmailAddresses = nil
	}

	derBytes, err := x509.CreateCertificate(rand.Reader, template, s.ca, template.PublicKey, s.priv)
	if err != nil {
		return nil, cferr.Wrap(cferr.CertificateError, cferr.Unknown, err)
	}
	if initRoot {
		s.ca, err = x509.ParseCertificate(derBytes)
		if err != nil {
			return nil, cferr.Wrap(cferr.CertificateError, cferr.ParseFailed, err)
		}
	}

	cert = pem.EncodeToMemory(&pem.Block{Type: "CERTIFICATE", Bytes: derBytes})
	log.Infof("signed certificate with serial number %d", template.SerialNumber)
	return
}
Exemple #3
0
// FillTemplate is a utility function that tries to load as much of
// the certificate template as possible from the profiles and current
// template. It fills in the key uses, expiration, revocation URLs
// and SKI.
func FillTemplate(template *x509.Certificate, defaultProfile, profile *config.SigningProfile) error {
	ski, err := ComputeSKI(template)

	var (
		eku             []x509.ExtKeyUsage
		ku              x509.KeyUsage
		backdate        time.Duration
		expiry          time.Duration
		notBefore       time.Time
		notAfter        time.Time
		crlURL, ocspURL string
	)

	// The third value returned from Usages is a list of unknown key usages.
	// This should be used when validating the profile at load, and isn't used
	// here.
	ku, eku, _ = profile.Usages()
	if profile.IssuerURL == nil {
		profile.IssuerURL = defaultProfile.IssuerURL
	}

	if ku == 0 && len(eku) == 0 {
		return cferr.New(cferr.PolicyError, cferr.NoKeyUsages)
	}

	if expiry = profile.Expiry; expiry == 0 {
		expiry = defaultProfile.Expiry
	}

	if crlURL = profile.CRL; crlURL == "" {
		crlURL = defaultProfile.CRL
	}
	if ocspURL = profile.OCSP; ocspURL == "" {
		ocspURL = defaultProfile.OCSP
	}
	if backdate = profile.Backdate; backdate == 0 {
		backdate = -5 * time.Minute
	} else {
		backdate = -1 * profile.Backdate
	}

	if !profile.NotBefore.IsZero() {
		notBefore = profile.NotBefore.UTC()
	} else {
		notBefore = time.Now().Round(time.Minute).Add(backdate).UTC()
	}

	if !profile.NotAfter.IsZero() {
		notAfter = profile.NotAfter.UTC()
	} else {
		notAfter = notBefore.Add(expiry).UTC()
	}

	template.NotBefore = notBefore
	template.NotAfter = notAfter
	template.KeyUsage = ku
	template.ExtKeyUsage = eku
	template.BasicConstraintsValid = true
	template.IsCA = profile.CA
	template.SubjectKeyId = ski

	if ocspURL != "" {
		template.OCSPServer = []string{ocspURL}
	}
	if crlURL != "" {
		template.CRLDistributionPoints = []string{crlURL}
	}

	if len(profile.IssuerURL) != 0 {
		template.IssuingCertificateURL = profile.IssuerURL
	}
	if len(profile.Policies) != 0 {
		err = addPolicies(template, profile.Policies)
		if err != nil {
			return cferr.Wrap(cferr.PolicyError, cferr.InvalidPolicy, err)
		}
	}
	if profile.OCSPNoCheck {
		ocspNoCheckExtension := pkix.Extension{
			Id:       asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 48, 1, 5},
			Critical: false,
			Value:    []byte{0x05, 0x00},
		}
		template.ExtraExtensions = append(template.ExtraExtensions, ocspNoCheckExtension)
	}

	return nil
}
Exemple #4
0
func (s *Signer) sign(template *x509.Certificate, profile *config.SigningProfile) (cert []byte, err error) {
	pub := template.PublicKey
	encodedpub, err := x509.MarshalPKIXPublicKey(pub)
	if err != nil {
		return
	}
	pubhash := sha1.New()
	pubhash.Write(encodedpub)

	if profile == nil {
		profile = s.Policy.Default
	}

	var (
		eku             []x509.ExtKeyUsage
		ku              x509.KeyUsage
		expiry          time.Duration
		crlURL, ocspURL string
	)

	// The third value returned from Usages is a list of unknown key usages.
	// This should be used when validating the profile at load, and isn't used
	// here.
	ku, eku, _ = profile.Usages()
	expiry = profile.Expiry
	if profile.IssuerURL == nil {
		profile.IssuerURL = s.Policy.Default.IssuerURL
	}

	if ku == 0 && len(eku) == 0 {
		err = cferr.New(cferr.PolicyError, cferr.NoKeyUsages, errors.New("no key usage available"))
		return
	}

	if expiry == 0 {
		expiry = s.Policy.Default.Expiry
	}

	if crlURL = profile.CRL; crlURL == "" {
		crlURL = s.Policy.Default.CRL
	}
	if ocspURL = profile.OCSP; ocspURL == "" {
		ocspURL = s.Policy.Default.OCSP
	}

	now := time.Now()
	serialNumber, err := rand.Int(rand.Reader, new(big.Int).SetInt64(math.MaxInt64))
	if err != nil {
		err = cferr.New(cferr.CertificateError, cferr.Unknown, err)
	}

	template.SerialNumber = serialNumber
	template.NotBefore = now.Add(-5 * time.Minute).UTC()
	template.NotAfter = now.Add(expiry).UTC()
	template.KeyUsage = ku
	template.ExtKeyUsage = eku
	template.BasicConstraintsValid = true
	template.IsCA = profile.CA
	template.SubjectKeyId = pubhash.Sum(nil)

	if ocspURL != "" {
		template.OCSPServer = []string{ocspURL}
	}
	if crlURL != "" {
		template.CRLDistributionPoints = []string{crlURL}
	}

	if len(profile.IssuerURL) != 0 {
		template.IssuingCertificateURL = profile.IssuerURL
	}

	var initRoot bool
	if s.CA == nil {
		if !template.IsCA {
			err = cferr.New(cferr.PolicyError, cferr.InvalidRequest, nil)
			return
		}
		template.DNSNames = nil
		s.CA = template
		initRoot = true
		template.MaxPathLen = 2
	} else if template.IsCA {
		template.MaxPathLen = 1
		template.DNSNames = nil
	}

	derBytes, err := x509.CreateCertificate(rand.Reader, template, s.CA, pub, s.Priv)
	if err != nil {
		return
	}
	if initRoot {
		s.CA, err = x509.ParseCertificate(derBytes)
		if err != nil {
			err = cferr.New(cferr.CertificateError, cferr.ParseFailed, err)
			return
		}
	}
	cert = pem.EncodeToMemory(&pem.Block{Type: "CERTIFICATE", Bytes: derBytes})
	return
}
Exemple #5
0
// Sign signs a new certificate based on the PEM-encoded client
// certificate or certificate request with the signing profile,
// specified by profileName.
func (s *Signer) Sign(req signer.SignRequest) (cert []byte, err error) {
	profile, err := signer.Profile(s, req.Profile)
	if err != nil {
		return
	}

	block, _ := pem.Decode([]byte(req.Request))
	if block == nil {
		return nil, cferr.New(cferr.CSRError, cferr.DecodeFailed)
	}

	if block.Type != "NEW CERTIFICATE REQUEST" && block.Type != "CERTIFICATE REQUEST" {
		return nil, cferr.Wrap(cferr.CSRError,
			cferr.BadRequest, errors.New("not a certificate or csr"))
	}

	csrTemplate, err := signer.ParseCertificateRequest(s, block.Bytes)
	if err != nil {
		return nil, err
	}

	// Copy out only the fields from the CSR authorized by policy.
	safeTemplate := x509.Certificate{}
	// If the profile contains no explicit whitelist, assume that all fields
	// should be copied from the CSR.
	if profile.CSRWhitelist == nil {
		safeTemplate = *csrTemplate
	} else {
		if profile.CSRWhitelist.Subject {
			safeTemplate.Subject = csrTemplate.Subject
		}
		if profile.CSRWhitelist.PublicKeyAlgorithm {
			safeTemplate.PublicKeyAlgorithm = csrTemplate.PublicKeyAlgorithm
		}
		if profile.CSRWhitelist.PublicKey {
			safeTemplate.PublicKey = csrTemplate.PublicKey
		}
		if profile.CSRWhitelist.SignatureAlgorithm {
			safeTemplate.SignatureAlgorithm = csrTemplate.SignatureAlgorithm
		}
		if profile.CSRWhitelist.DNSNames {
			safeTemplate.DNSNames = csrTemplate.DNSNames
		}
		if profile.CSRWhitelist.IPAddresses {
			safeTemplate.IPAddresses = csrTemplate.IPAddresses
		}
		if profile.CSRWhitelist.EmailAddresses {
			safeTemplate.EmailAddresses = csrTemplate.EmailAddresses
		}
	}

	if req.CRLOverride != "" {
		safeTemplate.CRLDistributionPoints = []string{req.CRLOverride}
	}

	if safeTemplate.IsCA {
		if !profile.CA {
			return nil, cferr.New(cferr.CertificateError, cferr.InvalidRequest)
		}

		if s.ca != nil && s.ca.MaxPathLen > 0 {
			if safeTemplate.MaxPathLen >= s.ca.MaxPathLen {
				// do not sign a cert with pathlen > current
				return nil, cferr.New(cferr.CertificateError, cferr.InvalidRequest)
			}
		} else if s.ca != nil && s.ca.MaxPathLen == 0 && s.ca.MaxPathLenZero {
			// signer has pathlen of 0, do not sign more intermediate CAs
			return nil, cferr.New(cferr.CertificateError, cferr.InvalidRequest)
		}
	}

	OverrideHosts(&safeTemplate, req.Hosts)
	safeTemplate.Subject = PopulateSubjectFromCSR(req.Subject, safeTemplate.Subject)

	// If there is a whitelist, ensure that both the Common Name and SAN DNSNames match
	if profile.NameWhitelist != nil {
		if safeTemplate.Subject.CommonName != "" {
			if profile.NameWhitelist.Find([]byte(safeTemplate.Subject.CommonName)) == nil {
				return nil, cferr.New(cferr.PolicyError, cferr.InvalidPolicy)
			}
		}
		for _, name := range safeTemplate.DNSNames {
			if profile.NameWhitelist.Find([]byte(name)) == nil {
				return nil, cferr.New(cferr.PolicyError, cferr.InvalidPolicy)
			}
		}
		for _, name := range safeTemplate.EmailAddresses {
			if profile.NameWhitelist.Find([]byte(name)) == nil {
				return nil, cferr.New(cferr.PolicyError, cferr.InvalidPolicy)
			}
		}
	}

	if profile.ClientProvidesSerialNumbers {
		if req.Serial == nil {
			return nil, cferr.New(cferr.CertificateError, cferr.MissingSerial)
		}
		safeTemplate.SerialNumber = req.Serial
	} else {
		// RFC 5280 4.1.2.2:
		// Certificate users MUST be able to handle serialNumber
		// values up to 20 octets.  Conforming CAs MUST NOT use
		// serialNumber values longer than 20 octets.
		//
		// If CFSSL is providing the serial numbers, it makes
		// sense to use the max supported size.
		serialNumber := make([]byte, 20)
		_, err = io.ReadFull(rand.Reader, serialNumber)
		if err != nil {
			return nil, cferr.Wrap(cferr.CertificateError, cferr.Unknown, err)
		}

		// SetBytes interprets buf as the bytes of a big-endian
		// unsigned integer. The leading byte should be masked
		// off to ensure it isn't negative.
		serialNumber[0] &= 0x7F

		safeTemplate.SerialNumber = new(big.Int).SetBytes(serialNumber)
	}

	if len(req.Extensions) > 0 {
		for _, ext := range req.Extensions {
			oid := asn1.ObjectIdentifier(ext.ID)
			if !profile.ExtensionWhitelist[oid.String()] {
				return nil, cferr.New(cferr.CertificateError, cferr.InvalidRequest)
			}

			rawValue, err := hex.DecodeString(ext.Value)
			if err != nil {
				return nil, cferr.Wrap(cferr.CertificateError, cferr.InvalidRequest, err)
			}

			safeTemplate.ExtraExtensions = append(safeTemplate.ExtraExtensions, pkix.Extension{
				Id:       oid,
				Critical: ext.Critical,
				Value:    rawValue,
			})
		}
	}

	var certTBS = safeTemplate

	if len(profile.CTLogServers) > 0 {
		// Add a poison extension which prevents validation
		var poisonExtension = pkix.Extension{Id: signer.CTPoisonOID, Critical: true, Value: []byte{0x05, 0x00}}
		var poisonedPreCert = certTBS
		poisonedPreCert.ExtraExtensions = append(safeTemplate.ExtraExtensions, poisonExtension)
		cert, err = s.sign(&poisonedPreCert, profile)
		if err != nil {
			return
		}

		derCert, _ := pem.Decode(cert)
		prechain := []ct.ASN1Cert{derCert.Bytes, s.ca.Raw}
		var sctList []ct.SignedCertificateTimestamp

		for _, server := range profile.CTLogServers {
			log.Infof("submitting poisoned precertificate to %s", server)
			var ctclient = client.New(server)
			var resp *ct.SignedCertificateTimestamp
			resp, err = ctclient.AddPreChain(prechain)
			if err != nil {
				return nil, cferr.Wrap(cferr.CTError, cferr.PrecertSubmissionFailed, err)
			}
			sctList = append(sctList, *resp)
		}

		var serializedSCTList []byte
		serializedSCTList, err = serializeSCTList(sctList)
		if err != nil {
			return nil, cferr.Wrap(cferr.CTError, cferr.Unknown, err)
		}

		// Serialize again as an octet string before embedding
		serializedSCTList, err = asn1.Marshal(serializedSCTList)
		if err != nil {
			return nil, cferr.Wrap(cferr.CTError, cferr.Unknown, err)
		}

		var SCTListExtension = pkix.Extension{Id: signer.SCTListOID, Critical: false, Value: serializedSCTList}
		certTBS.ExtraExtensions = append(certTBS.ExtraExtensions, SCTListExtension)
	}
	var signedCert []byte
	signedCert, err = s.sign(&certTBS, profile)
	if err != nil {
		return nil, err
	}

	if s.dbAccessor != nil {
		var certRecord = certdb.CertificateRecord{
			Serial: certTBS.SerialNumber.String(),
			// this relies on the specific behavior of x509.CreateCertificate
			// which updates certTBS AuthorityKeyId from the signer's SubjectKeyId
			AKI:     hex.EncodeToString(certTBS.AuthorityKeyId),
			CALabel: req.Label,
			Status:  "good",
			Expiry:  certTBS.NotAfter,
			PEM:     string(signedCert),
		}

		err = s.dbAccessor.InsertCertificate(certRecord)
		if err != nil {
			return nil, err
		}
		log.Debug("saved certificate with serial number ", certTBS.SerialNumber)
	}

	return signedCert, nil
}