private byte[] getPlaintext(uint version, MessageKeys messageKeys, byte[] cipherText)
{
try
{
//Cipher cipher;
if (version >= 3)
{
//cipher = getCipher(Cipher.DECRYPT_MODE, messageKeys.getCipherKey(), messageKeys.getIv());
return Decrypt.aesCbcPkcs5(cipherText, messageKeys.getCipherKey(), messageKeys.getIv());
}
else
{
//cipher = getCipher(Cipher.DECRYPT_MODE, messageKeys.getCipherKey(), messageKeys.getCounter())
return Decrypt.aesCtr(cipherText, messageKeys.getCipherKey(), messageKeys.getCounter());
}
}
catch (/*IllegalBlockSizeException | BadPadding*/Exception e)
{
throw new InvalidMessageException(e);
}
}
public void setMessageKeys(ECPublicKey senderEphemeral, MessageKeys messageKeys)
{
Pair<Chain, uint> chainAndIndex = getReceiverChain(senderEphemeral);
Chain chain = chainAndIndex.first();
Chain.Types.MessageKey messageKeyStructure = Chain.Types.MessageKey.CreateBuilder()
.SetCipherKey(ByteString.CopyFrom(messageKeys.getCipherKey()/*.getEncoded()*/))
.SetMacKey(ByteString.CopyFrom(messageKeys.getMacKey()/*.getEncoded()*/))
.SetIndex(messageKeys.getCounter())
.SetIv(ByteString.CopyFrom(messageKeys.getIv()/*.getIV()*/))
.Build();
Chain.Builder updatedChain = chain.ToBuilder().AddMessageKeys(messageKeyStructure);
if (updatedChain.MessageKeysList.Count > MAX_MESSAGE_KEYS)
{
updatedChain.MessageKeysList.RemoveAt(0);
}
this.sessionStructure = this.sessionStructure.ToBuilder()
.SetReceiverChains((int)chainAndIndex.second(), updatedChain.Build()) // TODO: conv
.Build();
}
private byte[] getCiphertext(uint version, MessageKeys messageKeys, byte[] plaintext)
{
try
{
if (version >= 3)
{
//cipher = getCipher(Cipher.ENCRYPT_MODE, messageKeys.getCipherKey(), messageKeys.getIv());
return Encrypt.aesCbcPkcs5(plaintext, messageKeys.getCipherKey(), messageKeys.getIv());
}
else
{
//cipher = getCipher(Cipher.ENCRYPT_MODE, messageKeys.getCipherKey(), messageKeys.getCounter());
return Encrypt.aesCtr(plaintext, messageKeys.getCipherKey(), messageKeys.getCounter());
}
}
catch (/*IllegalBlockSizeException | BadPadding*/Exception e)
{
throw new Exception(e.Message);
}
}
public MessageKeys removeMessageKeys(ECPublicKey senderEphemeral, uint counter)
{
Pair<Chain, uint> chainAndIndex = getReceiverChain(senderEphemeral);
Chain chain = chainAndIndex.first();
if (chain == null)
{
return null;
}
List<Chain.Types.MessageKey> messageKeyList = new List<Chain.Types.MessageKey>(chain.MessageKeysList);
IEnumerator<Chain.Types.MessageKey> messageKeyIterator = messageKeyList.GetEnumerator();
MessageKeys result = null;
while (messageKeyIterator.MoveNext()) //hasNext()
{
Chain.Types.MessageKey messageKey = messageKeyIterator.Current; // next()
if (messageKey.Index == counter)
{
result = new MessageKeys(messageKey.CipherKey.ToByteArray(),
messageKey.MacKey.ToByteArray(),
messageKey.Iv.ToByteArray(),
messageKey.Index);
messageKeyList.Remove(messageKey); //messageKeyIterator.remove();
break;
}
}
Chain updatedChain = chain.ToBuilder().ClearMessageKeys()
.AddRangeMessageKeys(messageKeyList) // AddAllMessageKeys
.Build();
this.sessionStructure = this.sessionStructure.ToBuilder()
.SetReceiverChains((int)chainAndIndex.second(), updatedChain) // TODO: conv
.Build();
return result;
}
