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decrypted return SecretBox has wrong message authentication code (MAC) #71
Description
Activity
This issue is still there. Here is my code:
Encryption
final streamCipherAlgorithm = crypto.Xchacha20.poly1305Aead(); final nonce = streamCipherAlgorithm.newNonce(); crypto.SecretKey secretKey = await streamCipherAlgorithm .newSecretKeyFromBytes(argonResult.rawBytes); crypto.SecretBox secretBox = await streamCipherAlgorithm.encrypt( utf8.encode(initialMessage), secretKey: secretKey, nonce: nonce, aad: utf8.encode(associatedData), ); String encryptedInitialMessage = base64Encode(secretBox.cipherText); // encryptedInitialMessage is sent to the other party along with Mac and nonce.Decryption
crypto.SecretBox secretBox = crypto.SecretBox( base64Decode(encryptedInitialMessage), nonce: base64Decode(nonce), mac: crypto.Mac( base64Decode( mac, ), ), );Decryption fails with 'SecretBox has wrong Message Authentication Code (MAC)' error.
I have tried using the 'Cipher' class as shown in the example, still fails on decryption with the same exception.
I believe any possible issue was fixed in cryptography 2.2.0 + cryptography_flutter 2.1.0.
Hi,
I received from python the Ciphertext (this is formated from StringEcrypted + first 4 elements from MAC.
When I'll try to decrypt the message I received wrong MAC.
I think the problem is on MAC. I'm able to set the MAC length with 4 on the SecretBox?
I'll add the code:
Future<List> decrypt(List message) async {
final algorithm = AesGcm.with128bits();
final key = await kdf(isEncrypt: true);
final secretKey = SecretKey(key);
final mac = Mac(message.skip(message.length - 4).toList());
final secretMessage =
SecretBox(message.take(message.length - 4).toList(), nonce: HEX.decode(cpIV), mac: mac);
final clearText = await algorithm.decrypt(secretMessage, secretKey: secretKey);
print(clearText);
return clearText;
}
SecretBox details
"Nonce: [174, 1, 226, 226, 211, 55, 4, 206, 188, 172, 17, 149]"
"Ciphertext: [179, 43, 17]"
"MAC: [255, 47, 7, 170]"