func (pk *PrivateKey) parse(r io.Reader) (err error) {
err = (&pk.PublicKey).parse(r)
if err != nil {
return
}
var buf [1]byte
_, err = readFull(r, buf[:])
if err != nil {
return
}
s2kType := buf[0]
switch s2kType {
case 0:
pk.s2k = nil
pk.Encrypted = false
case 254, 255:
_, err = readFull(r, buf[:])
if err != nil {
return
}
pk.cipher = CipherFunction(buf[0])
pk.Encrypted = true
pk.s2k, err = s2k.Parse(r)
if err != nil {
return
}
if s2kType == 254 {
pk.sha1Checksum = true
}
default:
return errors.UnsupportedError("deprecated s2k function in private key")
}
if pk.Encrypted {
blockSize := pk.cipher.blockSize()
if blockSize == 0 {
return errors.UnsupportedError("unsupported cipher in private key: " + strconv.Itoa(int(pk.cipher)))
}
pk.iv = make([]byte, blockSize)
_, err = readFull(r, pk.iv)
if err != nil {
return
}
}
pk.encryptedData, err = ioutil.ReadAll(r)
if err != nil {
return
}
if !pk.Encrypted {
return pk.parsePrivateKey(pk.encryptedData)
}
return
}
func (ske *SymmetricKeyEncrypted) parse(r io.Reader) error {
// RFC 4880, section 5.3.
var buf [2]byte
if _, err := readFull(r, buf[:]); err != nil {
return err
}
if buf[0] != symmetricKeyEncryptedVersion {
return errors.UnsupportedError("SymmetricKeyEncrypted version")
}
ske.CipherFunc = CipherFunction(buf[1])
if ske.CipherFunc.KeySize() == 0 {
return errors.UnsupportedError("unknown cipher: " + strconv.Itoa(int(buf[1])))
}
var err error
ske.s2k, err = s2k.Parse(r)
if err != nil {
return err
}
if ske.s2k == nil {
return errors.UnsupportedError("can't use dummy S2K for symmetric key encryption")
}
encryptedKey := make([]byte, maxSessionKeySizeInBytes)
// The session key may follow. We just have to try and read to find
// out. If it exists then we limit it to maxSessionKeySizeInBytes.
n, err := readFull(r, encryptedKey)
if err != nil && err != io.ErrUnexpectedEOF {
return err
}
if n != 0 {
if n == maxSessionKeySizeInBytes {
return errors.UnsupportedError("oversized encrypted session key")
}
ske.encryptedKey = encryptedKey[:n]
}
return nil
}
func (pk *PrivateKey) parse(r io.Reader) (err error) {
err = (&pk.PublicKey).parse(r)
if err != nil {
return
}
var buf [1]byte
_, err = readFull(r, buf[:])
if err != nil {
return
}
s2kType := buf[0]
switch s2kType {
case 0:
pk.s2k = nil
pk.Encrypted = false
case 254, 255:
_, err = readFull(r, buf[:])
if err != nil {
return
}
pk.cipher = CipherFunction(buf[0])
pk.Encrypted = true
pk.s2k, err = s2k.Parse(r)
if err != nil {
return
}
if s2kType == 254 {
pk.sha1Checksum = true
}
// S2K == nil implies that we got a "GNU Dummy" S2K. For instance,
// because our master secret key is on a USB key in a vault somewhere.
// In that case, there is no further data to consume here.
if pk.s2k == nil {
pk.Encrypted = false
return
}
default:
return errors.UnsupportedError("deprecated s2k function in private key")
}
if pk.Encrypted {
blockSize := pk.cipher.blockSize()
if blockSize == 0 {
return errors.UnsupportedError("unsupported cipher in private key: " + strconv.Itoa(int(pk.cipher)))
}
pk.iv = make([]byte, blockSize)
_, err = readFull(r, pk.iv)
if err != nil {
return
}
}
pk.encryptedData, err = ioutil.ReadAll(r)
if err != nil {
return
}
if !pk.Encrypted {
return pk.parsePrivateKey(pk.encryptedData)
}
return
}