Add certificate management funcs

provisioner/cert.go

@@ -0,0 +1,152 @@
+package provisioner
+
+import (
+	"bytes"
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/tls"
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"encoding/pem"
+	"math/big"
+	"net"
+	"time"
+)
+
+func newCertificate(org string) (*x509.Certificate, error) {
+	now := time.Now()
+	// need to set notBefore slightly in the past to account for time
+	// skew in the VMs otherwise the certs sometimes are not yet valid
+	notBefore := time.Date(now.Year(), now.Month(), now.Day(), now.Hour(), now.Minute()-5, 0, 0, time.Local)
+	notAfter := notBefore.Add(time.Hour * 24 * 1080)
+
+	serialNumberLimit := new(big.Int).Lsh(big.NewInt(1), 128)
+	serialNumber, err := rand.Int(rand.Reader, serialNumberLimit)
+	if err != nil {
+		return nil, err
+	}
+
+	return &x509.Certificate{
+		SerialNumber: serialNumber,
+		Subject: pkix.Name{
+			Organization: []string{org},
+		},
+		NotBefore: notBefore,
+		NotAfter:  notAfter,
+
+		KeyUsage:              x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature | x509.KeyUsageKeyAgreement,
+		BasicConstraintsValid: true,
+	}, nil
+
+}
+
+func GenerateCACertificate(org string) ([]byte, []byte, error) {
+	template, err := newCertificate(org)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	template.IsCA = true
+	template.KeyUsage |= x509.KeyUsageCertSign
+	template.KeyUsage |= x509.KeyUsageKeyEncipherment
+	template.KeyUsage |= x509.KeyUsageKeyAgreement
+
+	priv, err := rsa.GenerateKey(rand.Reader, 2048)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	derBytes, err := x509.CreateCertificate(rand.Reader, template, template, &priv.PublicKey, priv)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	cert := new(bytes.Buffer)
+	key := new(bytes.Buffer)
+	pem.Encode(cert, &pem.Block{Type: "CERTIFICATE", Bytes: derBytes})
+	pem.Encode(key, &pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(priv)})
+
+	return cert.Bytes(), key.Bytes(), nil
+}
+
+func GenerateClientCertificate(org string, caCert, caKey []byte) ([]byte, []byte, error) {
+	template, err := newCertificate(org)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	template.ExtKeyUsage = []x509.ExtKeyUsage{x509.ExtKeyUsageClientAuth}
+	template.KeyUsage = x509.KeyUsageDigitalSignature
+
+	tlsCert, err := tls.X509KeyPair(caCert, caKey)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	priv, err := rsa.GenerateKey(rand.Reader, 2048)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	x509Cert, err := x509.ParseCertificate(tlsCert.Certificate[0])
+	if err != nil {
+		return nil, nil, err
+	}
+
+	derBytes, err := x509.CreateCertificate(rand.Reader, template, x509Cert, &priv.PublicKey, tlsCert.PrivateKey)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	cert := new(bytes.Buffer)
+	key := new(bytes.Buffer)
+
+	pem.Encode(cert, &pem.Block{Type: "CERTIFICATE", Bytes: derBytes})
+	pem.Encode(key, &pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(priv)})
+
+	return cert.Bytes(), key.Bytes(), nil
+}
+
+func GenerateServerCertificate(org string, caCert, caKey []byte, hosts []string) ([]byte, []byte, error) {
+	template, err := newCertificate(org)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	template.ExtKeyUsage = []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth}
+	for _, h := range hosts {
+		if ip := net.ParseIP(h); ip != nil {
+			template.IPAddresses = append(template.IPAddresses, ip)
+		} else {
+			template.DNSNames = append(template.DNSNames, h)
+		}
+	}
+
+	tlsCert, err := tls.X509KeyPair(caCert, caKey)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	priv, err := rsa.GenerateKey(rand.Reader, 2048)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	x509Cert, err := x509.ParseCertificate(tlsCert.Certificate[0])
+	if err != nil {
+		return nil, nil, err
+	}
+
+	derBytes, err := x509.CreateCertificate(rand.Reader, template, x509Cert, &priv.PublicKey, tlsCert.PrivateKey)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	cert := new(bytes.Buffer)
+	key := new(bytes.Buffer)
+
+	pem.Encode(cert, &pem.Block{Type: "CERTIFICATE", Bytes: derBytes})
+	pem.Encode(key, &pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(priv)})
+
+	return cert.Bytes(), key.Bytes(), nil
+}