示例#1
0
            public int TransformBlock(byte[] inputBuffer, int inputOffset, int inputCount, byte[] outputBuffer, int outputOffset)
            {
                int returnCount = inputCount;

                this.LengthCipher += inputCount;

                for (int i = 0; i < inputCount; i += OutputBlockSize)
                {
                    IncrementCounter();

                    byte[] iBuffer = new byte[InputBlockSize];
                    byte[] oBuffer = new byte[OutputBlockSize];

                    Array.Copy(inputBuffer, inputOffset + i, iBuffer, 0, InputBlockSize);
                    this.Aes.Encrypt(Counter, 0, oBuffer, 0);
                    oBuffer = iBuffer.Add(oBuffer);

                    if (Encrypt)
                    {
                        ByteTag = GaloisMultiplication.GMul128(oBuffer.Add(ByteTag), H);
                    }
                    else
                    {
                        ByteTag = GaloisMultiplication.GMul128(iBuffer.Add(ByteTag), H);
                    }

                    Array.Copy(oBuffer, 0, outputBuffer, outputOffset + i, OutputBlockSize);
                }

                return(returnCount);
            }
示例#2
0
            public byte[] TransformFinalBlock(byte[] inputBuffer, int inputOffset, int inputCount)
            {
                this.LengthCipher += inputCount;

                byte[] output = new byte[inputCount];

                byte[] oBuffer = new byte[OutputBlockSize];

                if (inputCount > 0)
                {
                    IncrementCounter();

                    byte[] iBuffer = new byte[InputBlockSize];

                    Array.Copy(inputBuffer, inputOffset, iBuffer, 0, InputBlockSize);
                    this.Aes.Encrypt(Counter, 0, oBuffer, 0);
                    oBuffer = iBuffer.Add(oBuffer);

                    if (Encrypt)
                    {
                        Array.Clear(oBuffer, inputCount, oBuffer.Length - inputCount);
                        ByteTag = GaloisMultiplication.GMul128(oBuffer.Add(ByteTag), H);
                    }
                    else
                    {
                        ByteTag = GaloisMultiplication.GMul128(iBuffer.Add(ByteTag), H);
                    }

                    Array.Copy(oBuffer, 0, output, 0, inputCount);
                }

                byte[] length = ConvertToByteArray(AdditionalData.Length * 8, LengthCipher * 8);
                ByteTag = GaloisMultiplication.GMul128(ByteTag.Add(length), H);
                this.Aes.Encrypt(InitialCounter, 0, oBuffer, 0);
                ByteTag = oBuffer.Add(ByteTag);

                if (Encrypt)
                {
                    SetTag();
                }
                else
                {
                    AssertAuthentication();
                }

                return(output);
            }
示例#3
0
            /// <summary>
            /// 1:		X0 = 0
            /// 2:		For i = 1; i <= m; i++
            ///		        Xi = (Xi-1 XOR Ai) * H
            /// </summary>
            private void CreateByteTagWithAAD()
            {
                ByteTag = new byte[OutputBlockSize];
                int blocks = (AdditionalData.Length % 16) == 0 ? AdditionalData.Length / 16 : AdditionalData.Length / 16 + 1;

                byte[] temp = new byte[OutputBlockSize];

                for (int i = 1; i <= blocks; i++)
                {
                    byte[] aadBlock = new byte[OutputBlockSize];
                    int    length   = AdditionalData.Length - ((i - 1) * 16) > 16 ? 16 : AdditionalData.Length - ((i - 1) * 16);
                    Array.Copy(AdditionalData, (i - 1) * 16, aadBlock, 0, length);
                    temp = GaloisMultiplication.GMul128(temp.Add(aadBlock), H);
                }

                Array.Copy(temp, 0, ByteTag, 0, OutputBlockSize);
            }
示例#4
0
            /// <summary>
            /// 3:		For i = 1; i <= n; i++
            ///             Xi = (Xi-1 XOR IV) * H
            /// 4:		T = (Xn XOR (0 || length(IV))) * H
            /// </summary>
            /// <param name="H"></param>
            /// <param name="IV"></param>
            /// <returns></returns>
            private byte[] GHashIV(byte[] H, byte[] IV)
            {
                int blocks = IV.Length / 16;

                blocks += IV.Length % 16 == 0 ? 1 : 2;
                byte[] temp = new byte[OutputBlockSize];

                for (int i = 1; i < blocks; i++)
                {
                    byte[] IVBlock  = new byte[OutputBlockSize];
                    int    cpLength = IV.Length - ((i - 1) * 16);
                    cpLength = cpLength > 16 ? 16 : cpLength;
                    Array.Copy(IV, (i - 1) * 16, IVBlock, 0, cpLength);
                    temp = GaloisMultiplication.GMul128(temp.Add(IVBlock), H);
                }

                return(GaloisMultiplication.GMul128(temp.Add(ConvertToByteArray(IV.Length * 8)), H));
            }