Ejemplo n.º 1
0
        /// <summary>
        /// Decrypt data.
        /// </summary>
        /// <param name="p">Decryption parameters</param>
        /// <returns>Decrypted data.</returns>
        public static byte[] DecryptAesGcm(AesGcmParameter p, GXByteBuffer data)
        {
            if (data == null || data.Size < 2)
            {
                throw new ArgumentOutOfRangeException("cryptedData");
            }
            byte[]  tmp;
            int     len;
            Command cmd = (Command)data.GetUInt8();

            switch (cmd)
            {
            case Command.GeneralGloCiphering:
            case Command.GeneralDedCiphering:
                len = GXCommon.GetObjectCount(data);
                if (len != 0)
                {
                    p.SystemTitle = new byte[len];
                    data.Get(p.SystemTitle);
                    if (p.Xml != null && p.Xml.Comments)
                    {
                        p.Xml.AppendComment(GXCommon.SystemTitleToString(Standard.DLMS, p.SystemTitle));
                    }
                }
                if (p.SystemTitle == null || p.SystemTitle.Length != 8)
                {
                    if (p.Xml == null)
                    {
                        throw new ArgumentNullException("Invalid sender system title.");
                    }
                    else
                    {
                        p.Xml.AppendComment("Invalid sender system title.");
                    }
                }
                break;

            case Command.GeneralCiphering:
            case Command.GloInitiateRequest:
            case Command.GloInitiateResponse:
            case Command.GloReadRequest:
            case Command.GloReadResponse:
            case Command.GloWriteRequest:
            case Command.GloWriteResponse:
            case Command.GloGetRequest:
            case Command.GloGetResponse:
            case Command.GloSetRequest:
            case Command.GloSetResponse:
            case Command.GloMethodRequest:
            case Command.GloMethodResponse:
            case Command.GloEventNotification:
            case Command.DedInitiateRequest:
            case Command.DedInitiateResponse:
            case Command.DedGetRequest:
            case Command.DedGetResponse:
            case Command.DedSetRequest:
            case Command.DedSetResponse:
            case Command.DedMethodRequest:
            case Command.DedMethodResponse:
            case Command.DedEventNotification:
            case Command.DedReadRequest:
            case Command.DedReadResponse:
            case Command.DedWriteRequest:
            case Command.DedWriteResponse:
            case Command.GloConfirmedServiceError:
            case Command.DedConfirmedServiceError:
                break;

            default:
                throw new ArgumentOutOfRangeException("cryptedData");
            }
            int    value         = 0;
            UInt64 transactionId = 0;

            if (cmd == Command.GeneralCiphering)
            {
                len = GXCommon.GetObjectCount(data);
                tmp = new byte[len];
                data.Get(tmp);
                GXByteBuffer t = new GXByteBuffer(tmp);
                transactionId = t.GetUInt64();
                len           = GXCommon.GetObjectCount(data);
                if (len != 0)
                {
                    tmp = new byte[len];
                    data.Get(tmp);
                    p.SystemTitle = tmp;
                }
                if (p.SystemTitle == null || p.SystemTitle.Length != 8)
                {
                    if (p.Xml == null)
                    {
                        throw new ArgumentNullException("Invalid sender system title.");
                    }
                    else
                    {
                        p.Xml.AppendComment("Invalid sender system title.");
                    }
                }
                len = GXCommon.GetObjectCount(data);
                tmp = new byte[len];
                data.Get(tmp);
                p.RecipientSystemTitle = tmp;
                // Get date time.
                len = GXCommon.GetObjectCount(data);
                if (len != 0)
                {
                    tmp = new byte[len];
                    data.Get(tmp);
                    p.DateTime = tmp;
                }
                // other-information
                len = data.GetUInt8();
                if (len != 0)
                {
                    tmp = new byte[len];
                    data.Get(tmp);
                    p.OtherInformation = tmp;
                }
                // KeyInfo OPTIONAL
                len = data.GetUInt8();
                // AgreedKey CHOICE tag.
                data.GetUInt8();
                // key-parameters
                len             = data.GetUInt8();
                value           = data.GetUInt8();
                p.KeyParameters = value;
                if (value == 1)
                {
                    // KeyAgreement.ONE_PASS_DIFFIE_HELLMAN
                    // key-ciphered-data
                    len = GXCommon.GetObjectCount(data);
                    tmp = new byte[len];
                    data.Get(tmp);
                    p.KeyCipheredData = tmp;
                }
                else if (value == 2)
                {
                    // KeyAgreement.STATIC_UNIFIED_MODEL
                    len = GXCommon.GetObjectCount(data);
                    if (len != 0)
                    {
                        throw new ArgumentException("Invalid key parameters");
                    }
                }
                else
                {
                    throw new ArgumentException("key-parameters");
                }
            }
            len = GXCommon.GetObjectCount(data);
            p.CipheredContent = data.Remaining();
            byte sc = (byte)data.GetUInt8();

            Enums.Security security = (Enums.Security)(sc & 0x30);
            if ((sc & 0x80) != 0)
            {
                System.Diagnostics.Debug.WriteLine("Compression is used.");
            }
            if ((sc & 0x40) != 0)
            {
                System.Diagnostics.Debug.WriteLine("Error: Key_Set is used.");
            }
            if ((sc & 0x20) != 0)
            {
                System.Diagnostics.Debug.WriteLine("Encryption is applied.");
            }

            SecuritySuite ss = (SecuritySuite)(sc & 0x3);

            p.Security = (byte)security;
            UInt32 invocationCounter = data.GetUInt32();

            p.InvocationCounter = invocationCounter;
            if (ss == SecuritySuite.Version2)
            {
                throw new NotImplementedException("Security Suite 2 is not implemented.");
            }
            System.Diagnostics.Debug.WriteLine("Decrypt settings: " + p.ToString());
            System.Diagnostics.Debug.WriteLine("Encrypted: " + GXCommon.ToHex(data.Data,
                                                                              false, data.Position, data.Size - data.Position));
            byte[] tag = new byte[12];
            byte[] encryptedData;
            int    length;

            if (security == Enums.Security.Authentication)
            {
                length        = data.Size - data.Position - 12;
                encryptedData = new byte[length];
                data.Get(encryptedData);
                data.Get(tag);
                // Check tag.
                EncryptAesGcm(p, encryptedData);
                if (!GXDLMSChipperingStream.TagsEquals(tag, p.CountTag))
                {
                    if (transactionId != 0)
                    {
                        p.InvocationCounter = transactionId;
                    }
                    if (p.Xml == null)
                    {
                        throw new GXDLMSException("Decrypt failed. Invalid tag.");
                    }
                    else
                    {
                        p.Xml.AppendComment("Decrypt failed. Invalid tag.");
                    }
                }
                return(encryptedData);
            }
            byte[] ciphertext = null;
            if (security == Enums.Security.Encryption)
            {
                length     = data.Size - data.Position;
                ciphertext = new byte[length];
                data.Get(ciphertext);
            }
            else if (security == Enums.Security.AuthenticationEncryption)
            {
                length     = data.Size - data.Position - 12;
                ciphertext = new byte[length];
                data.Get(ciphertext);
                data.Get(tag);
            }
            byte[] aad = GetAuthenticatedData(p, ciphertext),
            iv = GetNonse(invocationCounter, p.SystemTitle);
            GXDLMSChipperingStream gcm = new GXDLMSChipperingStream((byte)security, true,
                                                                    p.BlockCipherKey, aad, iv, tag);

            gcm.Write(ciphertext);
            if (transactionId != 0)
            {
                p.InvocationCounter = transactionId;
            }
            return(gcm.FlushFinalBlock());
        }
Ejemplo n.º 2
0
        /// <summary>
        /// Decrypt data.
        /// </summary>
        /// <param name="p">Decryption parameters</param>
        /// <returns>Decrypted data.</returns>
        public static byte[] DecryptAesGcm(AesGcmParameter p, GXByteBuffer data)
        {
            if (data == null || data.Size < 2)
            {
                throw new ArgumentOutOfRangeException("cryptedData");
            }
            byte[]  tmp;
            int     len;
            Command cmd = (Command)data.GetUInt8();

            switch (cmd)
            {
            case Command.GeneralGloCiphering:
                len = GXCommon.GetObjectCount(data);
                if (len != 0)
                {
                    p.SystemTitle = new byte[len];
                    data.Get(p.SystemTitle);
                }
                break;

            case Command.GeneralCiphering:
            case Command.GloInitiateRequest:
            case Command.GloInitiateResponse:
            case Command.GloReadRequest:
            case Command.GloReadResponse:
            case Command.GloWriteRequest:
            case Command.GloWriteResponse:
            case Command.GloGetRequest:
            case Command.GloGetResponse:
            case Command.GloSetRequest:
            case Command.GloSetResponse:
            case Command.GloMethodRequest:
            case Command.GloMethodResponse:
            case Command.GloEventNotificationRequest:
                break;

            default:
                throw new ArgumentOutOfRangeException("cryptedData");
            }
            int    value         = 0;
            UInt64 transactionId = 0;

            if (cmd == Command.GeneralCiphering)
            {
                len = GXCommon.GetObjectCount(data);
                tmp = new byte[len];
                data.Get(tmp);
                GXByteBuffer t = new GXByteBuffer(tmp);
                transactionId = t.GetUInt64();
                len           = GXCommon.GetObjectCount(data);
                tmp           = new byte[len];
                data.Get(tmp);
                p.SystemTitle = tmp;
                len           = GXCommon.GetObjectCount(data);
                tmp           = new byte[len];
                data.Get(tmp);
                p.RecipientSystemTitle = tmp;
                // Get date time.
                len = GXCommon.GetObjectCount(data);
                if (len != 0)
                {
                    tmp = new byte[len];
                    data.Get(tmp);
                    p.DateTime = tmp;
                }
                // other-information
                len = data.GetUInt8();
                if (len != 0)
                {
                    tmp = new byte[len];
                    data.Get(tmp);
                    p.OtherInformation = tmp;
                }
                // KeyInfo OPTIONAL
                len = data.GetUInt8();
                // AgreedKey CHOICE tag.
                data.GetUInt8();
                // key-parameters
                len             = data.GetUInt8();
                value           = data.GetUInt8();
                p.KeyParameters = value;
                if (value == 1)
                {
                    // KeyAgreement.ONE_PASS_DIFFIE_HELLMAN
                    // key-ciphered-data
                    len = GXCommon.GetObjectCount(data);
                    tmp = new byte[len];
                    data.Get(tmp);
                    p.KeyCipheredData = tmp;
                }
                else if (value == 2)
                {
                    // KeyAgreement.STATIC_UNIFIED_MODEL
                    len = GXCommon.GetObjectCount(data);
                    if (len != 0)
                    {
                        throw new ArgumentException("Invalid key parameters");
                    }
                }
                else
                {
                    throw new ArgumentException("key-parameters");
                }
            }
            len = GXCommon.GetObjectCount(data);
            p.CipheredContent = data.Remaining();
            byte sc = (byte)data.GetUInt8();

            Enums.Security security = (Enums.Security)(sc & 0x30);
            SecuritySuite  ss       = (SecuritySuite)(sc & 0x3);

            p.Security = security;
            UInt32 invocationCounter = data.GetUInt32();

            p.InvocationCounter = invocationCounter;
            if (ss != SecuritySuite.AesGcm128)
            {
                throw new NotImplementedException("Security Suite 1 is not implemented.");
            }
            System.Diagnostics.Debug.WriteLine("Decrypt settings: " + p.ToString());
            System.Diagnostics.Debug.WriteLine("Encrypted: " + GXCommon.ToHex(data.Data,
                                                                              false, data.Position, data.Size - data.Position));
            byte[] tag = new byte[12];
            byte[] encryptedData;
            int    length;

            if (security == Enums.Security.Authentication)
            {
                length        = data.Size - data.Position - 12;
                encryptedData = new byte[length];
                data.Get(encryptedData);
                data.Get(tag);
                // Check tag.
                EncryptAesGcm(p, encryptedData);
                if (!GXDLMSChipperingStream.TagsEquals(tag, p.CountTag))
                {
                    if (transactionId != 0)
                    {
                        p.InvocationCounter = transactionId;
                    }
                    throw new GXDLMSException("Decrypt failed. Invalid tag.");
                }
                return(encryptedData);
            }
            byte[] ciphertext = null;
            if (security == Enums.Security.Encryption)
            {
                length     = data.Size - data.Position;
                ciphertext = new byte[length];
                data.Get(ciphertext);
            }
            else if (security == Enums.Security.AuthenticationEncryption)
            {
                length     = data.Size - data.Position - 12;
                ciphertext = new byte[length];
                data.Get(ciphertext);
                data.Get(tag);
            }
            byte[] aad = GetAuthenticatedData(p, ciphertext),
            iv = GetNonse(invocationCounter, p.SystemTitle);
            GXDLMSChipperingStream gcm = new GXDLMSChipperingStream(security, true,
                                                                    p.BlockCipherKey, aad, iv, tag);

            gcm.Write(ciphertext);
            if (transactionId != 0)
            {
                p.InvocationCounter = transactionId;
            }
            return(gcm.FlushFinalBlock());

            /*
             * len = Gurux.DLMS.Internal.GXCommon.GetObjectCount(data);
             * p.Security = (Gurux.DLMS.Enums.Security)data.GetUInt8();
             * p.InvocationCounter = data.GetUInt32();
             * System.Diagnostics.Debug.WriteLine("Decrypt settings: " + p.ToString());
             * System.Diagnostics.Debug.WriteLine("Encrypted: " + GXCommon.ToHex(data.Array(), true));
             *
             * byte[] tag = new byte[12];
             * byte[] encryptedData;
             * int length;
             * if (p.Security == Gurux.DLMS.Enums.Security.Authentication)
             * {
             *  length = data.Size - data.Position - 12;
             *  encryptedData = new byte[length];
             *  data.Get(encryptedData);
             *  data.Get(tag);
             *  // Check tag.
             *  EncryptAesGcm(p, encryptedData);
             *  if (!GXDLMSChipperingStream.TagsEquals(tag, p.CountTag))
             *  {
             *      throw new GXDLMSException("Decrypt failed. Invalid tag.");
             *  }
             *  return encryptedData;
             * }
             * byte[] ciphertext = null;
             * if (p.Security == Gurux.DLMS.Enums.Security.Encryption)
             * {
             *  length = data.Size - data.Position;
             *  ciphertext = new byte[length];
             *  data.Get(ciphertext);
             * }
             * else if (p.Security == Gurux.DLMS.Enums.Security.AuthenticationEncryption)
             * {
             *  length = data.Size - data.Position - 12;
             *  ciphertext = new byte[length];
             *  data.Get(ciphertext);
             *  data.Get(tag);
             * }
             * byte[] aad = GetAuthenticatedData(p.Security, p.AuthenticationKey, ciphertext);
             * byte[] iv = GetNonse(p.InvocationCounter, p.SystemTitle);
             * GXDLMSChipperingStream gcm = new GXDLMSChipperingStream(p.Security, true, p.BlockCipherKey, aad, iv, tag);
             * gcm.Write(ciphertext);
             * ciphertext = gcm.FlushFinalBlock();
             * if (p.Security == Gurux.DLMS.Enums.Security.AuthenticationEncryption)
             * {
             *  // Check tag.
             *  EncryptAesGcm(p, ciphertext);
             *  if (!GXDLMSChipperingStream.TagsEquals(tag, p.CountTag))
             *  {
             *      //    throw new GXDLMSException("Decrypt failed. Invalid tag.");
             *  }
             * }
             * return ciphertext;
             */
        }