private static byte[] checksum(PGPDigestCalculator digCalc, byte[] bytes, int length)
throws PGPException {
if (digCalc != null) {
OutputStream dOut = digCalc.getOutputStream();
try {
dOut.write(bytes, 0, length);
dOut.close();
} catch (Exception e) {
throw new PGPException("checksum digest calculation failed: " + e.getMessage(), e);
}
return digCalc.getDigest();
} else {
int checksum = 0;
for (int i = 0; i != length; i++) {
checksum += bytes[i] & 0xff;
}
byte[] check = new byte[2];
check[0] = (byte) (checksum >> 8);
check[1] = (byte) checksum;
return check;
}
}
PGPSecretKey(
PGPPrivateKey privKey,
PGPPublicKey pubKey,
PGPDigestCalculator checksumCalculator,
boolean isMasterKey,
PBESecretKeyEncryptor keyEncryptor)
throws PGPException {
this.pub = pubKey;
BCPGObject secKey = (BCPGObject) privKey.getPrivateKeyDataPacket();
try {
ByteArrayOutputStream bOut = new ByteArrayOutputStream();
BCPGOutputStream pOut = new BCPGOutputStream(bOut);
pOut.writeObject(secKey);
byte[] keyData = bOut.toByteArray();
pOut.write(checksum(checksumCalculator, keyData, keyData.length));
int encAlgorithm = keyEncryptor.getAlgorithm();
if (encAlgorithm != SymmetricKeyAlgorithmTags.NULL) {
keyData = bOut.toByteArray(); // include checksum
byte[] encData = keyEncryptor.encryptKeyData(keyData, 0, keyData.length);
byte[] iv = keyEncryptor.getCipherIV();
S2K s2k = keyEncryptor.getS2K();
int s2kUsage;
if (checksumCalculator != null) {
if (checksumCalculator.getAlgorithm() != HashAlgorithmTags.SHA1) {
throw new PGPException("only SHA1 supported for key checksum calculations.");
}
s2kUsage = SecretKeyPacket.USAGE_SHA1;
} else {
s2kUsage = SecretKeyPacket.USAGE_CHECKSUM;
}
if (isMasterKey) {
this.secret = new SecretKeyPacket(pub.publicPk, encAlgorithm, s2kUsage, s2k, iv, encData);
} else {
this.secret =
new SecretSubkeyPacket(pub.publicPk, encAlgorithm, s2kUsage, s2k, iv, encData);
}
} else {
if (isMasterKey) {
this.secret =
new SecretKeyPacket(pub.publicPk, encAlgorithm, null, null, bOut.toByteArray());
} else {
this.secret =
new SecretSubkeyPacket(pub.publicPk, encAlgorithm, null, null, bOut.toByteArray());
}
}
} catch (PGPException e) {
throw e;
} catch (Exception e) {
throw new PGPException("Exception encrypting key", e);
}
}