/**
* Return a copy of the passed in secret key, encrypted using a new
* password and the passed in algorithm.
*
* @param key the PgpSecretKey to be copied.
* @param oldKeyDecryptor the current decryptor based on the current password for key.
* @param newKeyEncryptor a new encryptor based on a new password for encrypting the secret key material.
*/
public static PgpSecretKey CopyWithNewPassword(
PgpSecretKey key,
IPbeSecretKeyDecryptorProvider oldKeyDecryptor,
IPbeSecretKeyEncryptor newKeyEncryptor)
{
if (key.IsPrivateKeyEmpty)
{
throw new PgpException("no private key in this SecretKey - public key present only.");
}
byte[] rawKeyData = key.extractKeyData(oldKeyDecryptor);
int s2kUsage = key.secret.S2kUsage;
byte[] iv = null;
S2k s2k = null;
byte[] keyData = null;
SymmetricKeyAlgorithmTag newEncAlgorithm = SymmetricKeyAlgorithmTag.Null;
if (newKeyEncryptor == null || newKeyEncryptor.AlgorithmDetails.Algorithm == SymmetricKeyAlgorithmTag.Null)
{
s2kUsage = SecretKeyPacket.UsageNone;
if (key.secret.S2kUsage == SecretKeyPacket.UsageSha1) // SHA-1 hash, need to rewrite checksum
{
keyData = new byte[rawKeyData.Length - 18];
Array.Copy(rawKeyData, 0, keyData, 0, keyData.Length - 2);
byte[] check = checksum(null, keyData, keyData.Length - 2);
keyData[keyData.Length - 2] = check[0];
keyData[keyData.Length - 1] = check[1];
}
else
{
keyData = rawKeyData;
}
}
else
{
if (s2kUsage == SecretKeyPacket.UsageNone)
{
s2kUsage = SecretKeyPacket.UsageChecksum;
}
if (key.secret.PublicKeyPacket.Version < 4)
{
// Version 2 or 3 - RSA Keys only
keyData = new byte[rawKeyData.Length];
if (newKeyEncryptor.ChecksumCalculatorFactory.AlgorithmDetails.Algorithm != HashAlgorithmTag.MD5)
{
throw new PgpException("MD5 Digest Calculator required for version 3 key encryptor.");
}
//
// process 4 numbers
//
int pos = 0;
for (int i = 0; i != 4; i++)
{
int encLen = (((rawKeyData[pos] << 8) | (rawKeyData[pos + 1] & 0xff)) + 7) / 8;
keyData[pos] = rawKeyData[pos];
keyData[pos + 1] = rawKeyData[pos + 1];
byte[] tmp;
if (i == 0)
{
tmp = newKeyEncryptor.Wrap(Arrays.CopyOfRange(rawKeyData, pos + 2, pos + 2 + encLen)).Collect();
iv = newKeyEncryptor.AlgorithmDetails.GetIV();
}
else
{
byte[] tmpIv = new byte[iv.Length];
Array.Copy(keyData, pos - iv.Length, tmpIv, 0, tmpIv.Length);
newKeyEncryptor = newKeyEncryptor.WithIV(tmpIv);
tmp = newKeyEncryptor.Wrap(Arrays.CopyOfRange(rawKeyData, pos + 2, pos + 2 + encLen)).Collect();
}
Array.Copy(tmp, 0, keyData, pos + 2, tmp.Length);
pos += 2 + encLen;
}
//
// copy in checksum.
//
keyData[pos] = rawKeyData[pos];
keyData[pos + 1] = rawKeyData[pos + 1];
s2k = newKeyEncryptor.AlgorithmDetails.S2k;
newEncAlgorithm = newKeyEncryptor.AlgorithmDetails.Algorithm;
}
else
{
keyData = newKeyEncryptor.Wrap(rawKeyData).Collect();
iv = newKeyEncryptor.AlgorithmDetails.GetIV();
s2k = newKeyEncryptor.AlgorithmDetails.S2k;
newEncAlgorithm = newKeyEncryptor.AlgorithmDetails.Algorithm;
}
}
SecretKeyPacket secret;
if (key.secret is SecretSubkeyPacket)
{
secret = new SecretSubkeyPacket(key.secret.PublicKeyPacket,
newEncAlgorithm, s2kUsage, s2k, iv, keyData);
}
else
{
secret = new SecretKeyPacket(key.secret.PublicKeyPacket,
newEncAlgorithm, s2kUsage, s2k, iv, keyData);
}
return(new PgpSecretKey(secret, key.pub));
}
private static SecretKeyPacket buildSecretKeyPacket(bool isMasterKey, PgpPrivateKey privKey, PgpPublicKey pubKey, IPbeSecretKeyEncryptor keyEncryptor)
{
BcpgObject secKey = (BcpgObject)privKey.Key;
if (secKey == null)
{
if (isMasterKey)
{
return(new SecretKeyPacket(pubKey.publicPk, SymmetricKeyAlgorithmTag.Null, null, null, new byte[0]));
}
else
{
return(new SecretSubkeyPacket(pubKey.publicPk, SymmetricKeyAlgorithmTag.Null, null, null, new byte[0]));
}
}
try
{
MemoryOutputStream bOut = new MemoryOutputStream();
BcpgOutputStream pOut = new BcpgOutputStream(bOut);
pOut.WriteObject(secKey);
byte[] keyData = bOut.ToArray();
byte[] checkData = checksum(keyEncryptor.ChecksumCalculatorFactory, keyData, keyData.Length);
pOut.Write(checkData, 0, checkData.Length);
PgpPbeKeyEncryptionParameters encParams = keyEncryptor.AlgorithmDetails;
SymmetricKeyAlgorithmTag encAlgorithm = (keyEncryptor != null) ? encParams.Algorithm : SymmetricKeyAlgorithmTag.Null;
if (encAlgorithm != SymmetricKeyAlgorithmTag.Null)
{
keyData = bOut.ToArray(); // include checksum
byte[] encData = keyEncryptor.Wrap(keyData).Collect();
byte[] iv = encParams.GetIV();
S2k s2k = encParams.S2k;
int s2kUsage;
if (keyEncryptor.ChecksumCalculatorFactory != null)
{
if (keyEncryptor.ChecksumCalculatorFactory.AlgorithmDetails.Algorithm != HashAlgorithmTag.Sha1)
{
throw new PgpException("only SHA1 supported for key checksum calculations.");
}
s2kUsage = SecretKeyPacket.UsageSha1;
}
else
{
s2kUsage = SecretKeyPacket.UsageChecksum;
}
if (isMasterKey)
{
return(new SecretKeyPacket(pubKey.publicPk, encAlgorithm, s2kUsage, s2k, iv, encData));
}
else
{
return(new SecretSubkeyPacket(pubKey.publicPk, encAlgorithm, s2kUsage, s2k, iv, encData));
}
}
else
{
if (isMasterKey)
{
return(new SecretKeyPacket(pubKey.publicPk, encAlgorithm, null, null, bOut.ToArray()));
}
else
{
return(new SecretSubkeyPacket(pubKey.publicPk, encAlgorithm, null, null, bOut.ToArray()));
}
}
}
catch (PgpException e)
{
throw e;
}
catch (Exception e)
{
throw new PgpException("Exception encrypting key", e);
}
}