mirror of
https://github.com/edgelesssys/constellation.git
synced 2024-12-25 07:29:38 -05:00
95 lines
2.5 KiB
Go
95 lines
2.5 KiB
Go
/*
|
|
Copyright (c) Edgeless Systems GmbH
|
|
|
|
SPDX-License-Identifier: AGPL-3.0-only
|
|
*/
|
|
package sigstore
|
|
|
|
import (
|
|
"bytes"
|
|
"crypto"
|
|
"crypto/ecdsa"
|
|
"crypto/ed25519"
|
|
"crypto/rsa"
|
|
"crypto/x509"
|
|
"encoding/base64"
|
|
"encoding/pem"
|
|
"errors"
|
|
"fmt"
|
|
|
|
"github.com/secure-systems-lab/go-securesystemslib/encrypted"
|
|
"github.com/sigstore/sigstore/pkg/signature"
|
|
)
|
|
|
|
const (
|
|
cosignPrivateKeyPemType = "ENCRYPTED COSIGN PRIVATE KEY"
|
|
sigstorePrivateKeyPemType = "ENCRYPTED SIGSTORE PRIVATE KEY"
|
|
)
|
|
|
|
// Signer is used to sign the version file. Used for unit testing.
|
|
type Signer interface {
|
|
Sign(content []byte) (res []byte, err error)
|
|
}
|
|
|
|
// NewSigner returns a new Signer.
|
|
func NewSigner(cosignPwd, privKey []byte) Signer {
|
|
return signer{cosignPwd: cosignPwd, privKey: privKey}
|
|
}
|
|
|
|
type signer struct {
|
|
cosignPwd []byte // used to decrypt the cosign private key
|
|
privKey []byte // used to sign
|
|
}
|
|
|
|
func (s signer) Sign(content []byte) (signature []byte, err error) {
|
|
signature, err = SignContent(s.cosignPwd, s.privKey, content)
|
|
if err != nil {
|
|
return signature, fmt.Errorf("sign version file: %w", err)
|
|
}
|
|
return
|
|
}
|
|
|
|
// SignContent signs the content with the cosign encrypted private key and corresponding cosign password.
|
|
func SignContent(password, encryptedPrivateKey, content []byte) ([]byte, error) {
|
|
sv, err := loadPrivateKey(encryptedPrivateKey, password)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("loading private key: %w", err)
|
|
}
|
|
sig, err := sv.SignMessage(bytes.NewReader(content))
|
|
if err != nil {
|
|
return nil, fmt.Errorf("signing message: %w", err)
|
|
}
|
|
return []byte(base64.StdEncoding.EncodeToString(sig)), nil
|
|
}
|
|
|
|
func loadPrivateKey(key []byte, pass []byte) (signature.SignerVerifier, error) {
|
|
// Decrypt first
|
|
p, _ := pem.Decode(key)
|
|
if p == nil {
|
|
return nil, errors.New("invalid pem block")
|
|
}
|
|
if p.Type != cosignPrivateKeyPemType && p.Type != sigstorePrivateKeyPemType {
|
|
return nil, fmt.Errorf("unsupported pem type: %s", p.Type)
|
|
}
|
|
|
|
x509Encoded, err := encrypted.Decrypt(p.Bytes, pass)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("decrypt: %w", err)
|
|
}
|
|
|
|
pk, err := x509.ParsePKCS8PrivateKey(x509Encoded)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("parsing private key: %w", err)
|
|
}
|
|
switch pk := pk.(type) {
|
|
case *rsa.PrivateKey:
|
|
return signature.LoadRSAPKCS1v15SignerVerifier(pk, crypto.SHA256)
|
|
case *ecdsa.PrivateKey:
|
|
return signature.LoadECDSASignerVerifier(pk, crypto.SHA256)
|
|
case ed25519.PrivateKey:
|
|
return signature.LoadED25519SignerVerifier(pk)
|
|
default:
|
|
return nil, errors.New("unsupported key type")
|
|
}
|
|
}
|