key_pair.go

package ssh

import (
	"crypto/rsa"
	"crypto/rand"
	"encoding/pem"
	"crypto/x509"
	"testing"
	"golang.org/x/crypto/ssh"
	"github.com/gruntwork-io/terratest/modules/logger"
)

// A public and private key pair that can be used for SSH access
type KeyPair struct {
	PublicKey	string
	PrivateKey	string
}

// Generate an RSA Keypair and return the public and private keys
func GenerateRSAKeyPair(t *testing.T, keySize int) *KeyPair {
	keyPair, err := GenerateRSAKeyPairE(t, keySize)
	if err != nil {
		t.Fatal(err)
	}
	return keyPair
}

// Generate an RSA Keypair and return the public and private keys
func GenerateRSAKeyPairE(t *testing.T, keySize int) (*KeyPair, error) {
	logger.Logf(t, "Generating new public/private key of size %d", keySize)

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

	// Extract the private key
	keyPemBlock := &pem.Block{
		Type:	"RSA PRIVATE KEY",
		Bytes:	x509.MarshalPKCS1PrivateKey(rsaKeyPair),
	}

	keyPem := string(pem.EncodeToMemory(keyPemBlock))

	// Extract the public key
	sshPubKey, err := ssh.NewPublicKey(rsaKeyPair.Public())
	if err != nil {
		return nil, err
	}

	sshPubKeyBytes := ssh.MarshalAuthorizedKey(sshPubKey)
	sshPubKeyStr := string(sshPubKeyBytes)

	// Return
	return &KeyPair{ PublicKey: sshPubKeyStr, PrivateKey: keyPem }, nil
}