feat(libcrypto): move into the Portainer repository EE-5476 (#10230)

pkg/libcrypto/ssl.go

@@ -0,0 +1,82 @@
+package libcrypto
+
+import (
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rand"
+	"crypto/x509"
+	"encoding/pem"
+	"errors"
+	"math/big"
+	"net"
+	"os"
+	"time"
+)
+
+// GenerateCertsForHost generates a self-signed certificate for host and saves them at certPath and keyPath
+func GenerateCertsForHost(hostname, ip, certPath, keyPath string, expiry time.Time) error {
+	serialNumberLimit := new(big.Int).Lsh(big.NewInt(1), 128)
+	serialNumber, err := rand.Int(rand.Reader, serialNumberLimit)
+	if err != nil {
+		return err
+	}
+
+	template := x509.Certificate{
+		SerialNumber:          serialNumber,
+		NotAfter:              expiry,
+		NotBefore:             time.Now(),
+		KeyUsage:              x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
+		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
+		BasicConstraintsValid: true,
+	}
+
+	parsedIP := net.ParseIP(ip)
+	if parsedIP == nil {
+		return errors.New("Failed parsing host ip")
+	}
+
+	template.DNSNames = append(template.DNSNames, hostname)
+	template.IPAddresses = append(template.IPAddresses, parsedIP)
+
+	keyPair, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
+	if err != nil {
+		return err
+	}
+
+	encodedCert, err := x509.CreateCertificate(rand.Reader, &template, &template, &keyPair.PublicKey, keyPair)
+	if err != nil {
+		return err
+	}
+
+	err = createPEMEncodedFile(certPath, "CERTIFICATE", encodedCert)
+	if err != nil {
+		return err
+	}
+
+	key, err := x509.MarshalECPrivateKey(keyPair)
+	if err != nil {
+		return err
+	}
+
+	err = createPEMEncodedFile(keyPath, "EC PRIVATE KEY", key)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func createPEMEncodedFile(path, header string, data []byte) error {
+	file, err := os.OpenFile(path, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	err = pem.Encode(file, &pem.Block{Type: header, Bytes: data})
+	if err != nil {
+		return err
+	}
+
+	return nil
+}