pkg/tls/cert.go

package tls

import (
	"bytes"
	"crypto/rand"
	"crypto/rsa"
	"crypto/x509"
	"crypto/x509/pkix"
	"encoding/pem"
	"math/big"
	"time"
)

// NewFakeTLSCredentials generates a self-signed certificate and private key for testing.
func NewFakeTLSCredentials() ([]byte, []byte, error) {
	ca := &x509.Certificate{
		SerialNumber: big.NewInt(2023),
		Subject: pkix.Name{
			Organization:  []string{"Fake Org"},
			Country:       []string{"US"},
			Province:      []string{""},
			Locality:      []string{"Fake City"},
			StreetAddress: []string{"Fake Address"},
			PostalCode:    []string{"12345"},
		},
		NotBefore:             time.Now(),
		NotAfter:              time.Now().AddDate(10, 0, 0),
		IsCA:                  true,
		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageClientAuth, x509.ExtKeyUsageServerAuth},
		KeyUsage:              x509.KeyUsageDigitalSignature | x509.KeyUsageCertSign,
		BasicConstraintsValid: true,
	}

	caPrivKey, err := rsa.GenerateKey(rand.Reader, 4096)
	if err != nil {
		return nil, nil, err
	}

	cert := &x509.Certificate{
		SerialNumber: big.NewInt(2023),
		Subject: pkix.Name{
			Organization:  []string{"Fake Org"},
			Country:       []string{"US"},
			Province:      []string{""},
			Locality:      []string{"Fake City"},
			StreetAddress: []string{"Fake Address"},
			PostalCode:    []string{"94016"},
		},
		NotBefore:             time.Now(),
		NotAfter:              time.Now().AddDate(10, 0, 0),
		IsCA:                  true,
		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageClientAuth, x509.ExtKeyUsageServerAuth},
		KeyUsage:              x509.KeyUsageDigitalSignature | x509.KeyUsageCertSign,
		BasicConstraintsValid: true,
	}

	certPrivKey, err := rsa.GenerateKey(rand.Reader, 2048)
	if err != nil {
		return nil, nil, err
	}

	certBytes, err := x509.CreateCertificate(rand.Reader, cert, ca, &certPrivKey.PublicKey, caPrivKey)
	if err != nil {
		return nil, nil, err
	}

	certPEM := new(bytes.Buffer)
	pem.Encode(certPEM, &pem.Block{
		Type:  "CERTIFICATE",
		Bytes: certBytes,
	})
	certPrivKeyPEM := new(bytes.Buffer)
	pem.Encode(certPrivKeyPEM, &pem.Block{
		Type:  "RSA PRIVATE KEY",
		Bytes: x509.MarshalPKCS1PrivateKey(certPrivKey),
	})

	return certPEM.Bytes(), certPrivKeyPEM.Bytes(), nil
}