// CanonicalKeyID returns the ID of the public bytes version of a TUF key.
// On regular RSA/ECDSA TUF keys, this is just the key ID. On X509 RSA/ECDSA
// TUF keys, this is the key ID of the public key part of the key.
func CanonicalKeyID(k data.PublicKey) (string, error) {
switch k.Algorithm() {
case data.ECDSAx509Key, data.RSAx509Key:
return trustmanager.X509PublicKeyID(k)
default:
return k.ID(), nil
}
}
func initRoles(kdb *keys.KeyDB, rootKey, targetsKey, snapshotKey, timestampKey data.PublicKey) error {
rootRole, err := data.NewRole("root", 1, []string{rootKey.ID()}, nil, nil)
if err != nil {
return err
}
targetsRole, err := data.NewRole("targets", 1, []string{targetsKey.ID()}, nil, nil)
if err != nil {
return err
}
snapshotRole, err := data.NewRole("snapshot", 1, []string{snapshotKey.ID()}, nil, nil)
if err != nil {
return err
}
timestampRole, err := data.NewRole("timestamp", 1, []string{timestampKey.ID()}, nil, nil)
if err != nil {
return err
}
if err := kdb.AddRole(rootRole); err != nil {
return err
}
if err := kdb.AddRole(targetsRole); err != nil {
return err
}
if err := kdb.AddRole(snapshotRole); err != nil {
return err
}
if err := kdb.AddRole(timestampRole); err != nil {
return err
}
return nil
}
func (v Ed25519Verifier) Verify(key data.PublicKey, sig []byte, msg []byte) error {
var sigBytes [ed25519.SignatureSize]byte
if len(sig) != len(sigBytes) {
logrus.Infof("signature length is incorrect, must be %d, was %d.", ed25519.SignatureSize, len(sig))
return ErrInvalid
}
copy(sigBytes[:], sig)
var keyBytes [ed25519.PublicKeySize]byte
copy(keyBytes[:], key.Public())
if !ed25519.Verify(&keyBytes, msg, &sigBytes) {
logrus.Infof("failed ed25519 verification")
return ErrInvalid
}
return nil
}
// Verify does the actual check.
// N.B. We have not been able to make this work in a way that is compatible
// with PyCrypto.
func (v RSAPyCryptoVerifier) Verify(key data.PublicKey, sig []byte, msg []byte) error {
digest := sha256.Sum256(msg)
k, _ := pem.Decode([]byte(key.Public()))
if k == nil {
logrus.Infof("failed to decode PEM-encoded x509 certificate")
return ErrInvalid
}
pub, err := x509.ParsePKIXPublicKey(k.Bytes)
if err != nil {
logrus.Infof("failed to parse public key: %s\n", err)
return ErrInvalid
}
return verifyPSS(pub, digest[:], sig)
}
func (v Ed25519Verifier) Verify(key data.PublicKey, sig []byte, msg []byte) error {
if key.Algorithm() != data.ED25519Key {
return ErrInvalidKeyType{}
}
var sigBytes [ed25519.SignatureSize]byte
if len(sig) != ed25519.SignatureSize {
logrus.Infof("signature length is incorrect, must be %d, was %d.", ed25519.SignatureSize, len(sig))
return ErrInvalid
}
copy(sigBytes[:], sig)
var keyBytes [ed25519.PublicKeySize]byte
pub := key.Public()
if len(pub) != ed25519.PublicKeySize {
logrus.Errorf("public key is incorrect size, must be %d, was %d.", ed25519.PublicKeySize, len(pub))
return ErrInvalidKeyLength{msg: fmt.Sprintf("ed25519 public key must be %d bytes.", ed25519.PublicKeySize)}
}
n := copy(keyBytes[:], key.Public())
if n < ed25519.PublicKeySize {
logrus.Errorf("failed to copy the key, must have %d bytes, copied %d bytes.", ed25519.PublicKeySize, n)
return ErrInvalid
}
if !ed25519.Verify(&keyBytes, msg, &sigBytes) {
logrus.Infof("failed ed25519 verification")
return ErrInvalid
}
return nil
}
func getRSAPubKey(key data.PublicKey) (crypto.PublicKey, error) {
algorithm := key.Algorithm()
var pubKey crypto.PublicKey
switch algorithm {
case data.RSAx509Key:
pemCert, _ := pem.Decode([]byte(key.Public()))
if pemCert == nil {
logrus.Infof("failed to decode PEM-encoded x509 certificate")
return nil, ErrInvalid
}
cert, err := x509.ParseCertificate(pemCert.Bytes)
if err != nil {
logrus.Infof("failed to parse x509 certificate: %s\n", err)
return nil, ErrInvalid
}
pubKey = cert.PublicKey
case data.RSAKey:
var err error
pubKey, err = x509.ParsePKIXPublicKey(key.Public())
if err != nil {
logrus.Infof("failed to parse public key: %s\n", err)
return nil, ErrInvalid
}
default:
// only accept RSA keys
logrus.Infof("invalid key type for RSAPSS verifier: %s", algorithm)
return nil, ErrInvalidKeyType{}
}
return pubKey, nil
}
// Verify does the actual check.
func (v ECDSAVerifier) Verify(key data.PublicKey, sig []byte, msg []byte) error {
algorithm := key.Algorithm()
var pubKey crypto.PublicKey
switch algorithm {
case data.ECDSAx509Key:
pemCert, _ := pem.Decode([]byte(key.Public()))
if pemCert == nil {
logrus.Infof("failed to decode PEM-encoded x509 certificate for keyID: %s", key.ID())
logrus.Debugf("certificate bytes: %s", string(key.Public()))
return ErrInvalid
}
cert, err := x509.ParseCertificate(pemCert.Bytes)
if err != nil {
logrus.Infof("failed to parse x509 certificate: %s\n", err)
return ErrInvalid
}
pubKey = cert.PublicKey
case data.ECDSAKey:
var err error
pubKey, err = x509.ParsePKIXPublicKey(key.Public())
if err != nil {
logrus.Infof("Failed to parse private key for keyID: %s, %s\n", key.ID(), err)
return ErrInvalid
}
default:
// only accept ECDSA keys.
logrus.Infof("invalid key type for ECDSA verifier: %s", algorithm)
return ErrInvalidKeyType{}
}
ecdsaPubKey, ok := pubKey.(*ecdsa.PublicKey)
if !ok {
logrus.Infof("value isn't an ECDSA public key")
return ErrInvalid
}
sigLength := len(sig)
expectedOctetLength := 2 * ((ecdsaPubKey.Params().BitSize + 7) >> 3)
if sigLength != expectedOctetLength {
logrus.Infof("signature had an unexpected length")
return ErrInvalid
}
rBytes, sBytes := sig[:sigLength/2], sig[sigLength/2:]
r := new(big.Int).SetBytes(rBytes)
s := new(big.Int).SetBytes(sBytes)
digest := sha256.Sum256(msg)
if !ecdsa.Verify(ecdsaPubKey, digest[:], r, s) {
logrus.Infof("failed ECDSA signature validation")
return ErrInvalid
}
return nil
}
func (db *KeyDB) AddKey(k *data.PublicKey) {
db.keys[k.ID()] = k
}