C# (CSharp) I2PCore.TunnelLayer.I2NP.Data GarlicAESBlock.VerifyPayloadHash Exemples

Exemple #1

        public static (GarlicAESBlock, I2PSessionKey) EGDecryptGarlic(
            GarlicMessage garlic,
            I2PPrivateKey privkey)
        {
            var cipher = new CbcBlockCipher(new AesEngine());
            var egdata = garlic.EGData;

            var egbuf    = new BufLen(egdata, 0, 514);
            var egheader = ElGamalCrypto.Decrypt(egbuf, privkey, true);

            var sessionkey = new I2PSessionKey(new BufLen(egheader, 0, 32));
            var preiv      = new BufLen(egheader, 32, 32);
            var egpadding  = new BufLen(egheader, 64, 158);
            var aesbuf     = new BufLen(egdata, 514);

            var pivh = I2PHashSHA256.GetHash(preiv);

            cipher.Init(false, sessionkey.Key.ToParametersWithIV(new BufLen(pivh, 0, 16)));
            cipher.ProcessBytes(aesbuf);

            GarlicAESBlock aesblock =
                new GarlicAESBlock(new BufRefLen(aesbuf));

            if (!aesblock.VerifyPayloadHash())
            {
                throw new ChecksumFailureException("AES block hash check failed!");
            }

            return(aesblock, sessionkey);
        }

Exemple #2

        public static (GarlicAESBlock, I2PSessionKey) RetrieveAESBlock(
            GarlicMessage garlic,
            I2PPrivateKey privatekey,
            Func <I2PSessionTag, I2PSessionKey> findsessionkey)
        {
            GarlicAESBlock result;

            var cipher = new CbcBlockCipher(new AesEngine());

            var tag        = new I2PSessionTag(new BufRefLen(garlic.EGData, 0, 32));
            var sessionkey = findsessionkey?.Invoke(tag);

#if LOG_ALL_LEASE_MGMT
            Logging.LogDebug($"Garlic: Session key found {sessionkey}");
#endif
            if (sessionkey != null)
            {
                var aesbuf = new BufLen(garlic.EGData, 32);
                var pivh   = I2PHashSHA256.GetHash(tag.Value);

                cipher.Init(false, sessionkey.Key.ToParametersWithIV(new BufLen(pivh, 0, 16)));
                cipher.ProcessBytes(aesbuf);

                try
                {
                    result = new GarlicAESBlock(new BufRefLen(aesbuf));

                    if (!result.VerifyPayloadHash())
                    {
                        Logging.LogDebug("Garlic: DecryptMessage: AES block SHA256 check failed.");
                        return(null, null);
                    }

                    return(result, sessionkey);
                }
                catch (ArgumentException ex)
                {
                    Logging.Log("Garlic", ex);
                }
                catch (Exception ex)
                {
                    Logging.Log("Garlic", ex);
                    return(null, null);
                }
            }

#if LOG_ALL_LEASE_MGMT
            Logging.LogDebug("Garlic: No session key. Using ElGamal to decrypt.");
#endif

            try
            {
                (result, sessionkey) = Garlic.EGDecryptGarlic(garlic, privatekey);
#if LOG_ALL_LEASE_MGMT
                Logging.LogDebug($"Garlic: EG session key {sessionkey}");
#endif
            }
            catch (Exception ex)
            {
                Logging.LogDebug("Garlic: ElGamal DecryptMessage failed");
                Logging.LogDebugData($"ReceivedSessions {ex}");
                return(null, null);
            }

            return(result, sessionkey);
        }