/
sshkey-gen.go
79 lines (62 loc) · 1.73 KB
/
sshkey-gen.go
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package gitops
import (
"crypto/rand"
"crypto/rsa"
"crypto/x509"
"encoding/pem"
log "github.com/sirupsen/logrus"
"golang.org/x/crypto/ssh"
)
func GenerateKeys() (string, string, error) {
bitSize := 4096
privateKey, err := generatePrivateKey(bitSize)
if err != nil {
return "", "", err
}
publicKeyBytes, err := generatePublicKey(&privateKey.PublicKey)
if err != nil {
return "", "", err
}
privateKeyBytes := encodePrivateKeyToPEM(privateKey)
return string(publicKeyBytes), string(privateKeyBytes), nil
}
// generatePrivateKey creates a RSA Private Key of specified byte size
func generatePrivateKey(bitSize int) (*rsa.PrivateKey, error) {
// Private Key generation
privateKey, err := rsa.GenerateKey(rand.Reader, bitSize)
if err != nil {
return nil, err
}
// Validate Private Key
err = privateKey.Validate()
if err != nil {
return nil, err
}
log.Info("private Key generated")
return privateKey, nil
}
// encodePrivateKeyToPEM encodes Private Key from RSA to PEM format
func encodePrivateKeyToPEM(privateKey *rsa.PrivateKey) []byte {
// Get ASN.1 DER format
privDER := x509.MarshalPKCS1PrivateKey(privateKey)
// pem.Block
privBlock := pem.Block{
Type: "RSA PRIVATE KEY",
Headers: nil,
Bytes: privDER,
}
// Private key in PEM format
privatePEM := pem.EncodeToMemory(&privBlock)
return privatePEM
}
// generatePublicKey take a rsa.PublicKey and return bytes suitable for writing to .pub file
// returns in the format "ssh-rsa ..."
func generatePublicKey(privatekey *rsa.PublicKey) ([]byte, error) {
publicRsaKey, err := ssh.NewPublicKey(privatekey)
if err != nil {
return nil, err
}
pubKeyBytes := ssh.MarshalAuthorizedKey(publicRsaKey)
log.Info("public key generated")
return pubKeyBytes, nil
}