public byte[] decryptBytes(byte[] combined) throws IOException, InvalidMessageException {
try {
byte[][] parts =
Util.split(combined, PublicKey.KEY_SIZE, combined.length - PublicKey.KEY_SIZE);
PublicKey theirPublicKey = new PublicKey(parts[0], 0);
ECPrivateKey ourPrivateKey = asymmetricMasterSecret.getPrivateKey();
byte[] secret = Curve.calculateAgreement(theirPublicKey.getKey(), ourPrivateKey);
MasterCipher masterCipher = getMasterCipherForSecret(secret);
return masterCipher.decryptBytes(parts[1]);
} catch (InvalidKeyException e) {
throw new InvalidMessageException(e);
}
}
public byte[] encryptBytes(byte[] body) {
try {
ECPublicKey theirPublic = asymmetricMasterSecret.getDjbPublicKey();
ECKeyPair ourKeyPair = Curve.generateKeyPair();
byte[] secret = Curve.calculateAgreement(theirPublic, ourKeyPair.getPrivateKey());
MasterCipher masterCipher = getMasterCipherForSecret(secret);
byte[] encryptedBodyBytes = masterCipher.encryptBytes(body);
PublicKey ourPublicKey = new PublicKey(31337, ourKeyPair.getPublicKey());
byte[] publicKeyBytes = ourPublicKey.serialize();
return Util.combine(publicKeyBytes, encryptedBodyBytes);
} catch (InvalidKeyException e) {
throw new AssertionError(e);
}
}
