blowfishcfb.cs

source for advanced algorithm

                posOut += 8;
            }

            // store back the new IV
            iv[0] = (byte)(hi >> 24);
            iv[1] = (byte)(hi >> 16);
            iv[2] = (byte)(hi >>  8);
            iv[3] = (byte) hi       ;
            iv[4] = (byte)(lo >> 24);
            iv[5] = (byte)(lo >> 16);
            iv[6] = (byte)(lo >>  8);
            iv[7] = (byte) lo       ;

            // emit the rest
            for (int i = 0; i < rest; i++)
            {
                iv[i] = dataOut[posOut++] = (byte)(dataIn[posIn++] ^ iv[i]);
            }

            this.ivBytesLeft = iv.Length - rest;

            return count;
        }

        /// <see cref="BlowfishNET.BlowfishECB.Decrypt"/>
        public new int Decrypt(
            byte[] dataIn,
            int posIn,
            byte[] dataOut,
            int posOut,
            int count)
        {
            // same as above except that the ciphertext (input data) is what we keep...

            int end = posIn + count;

            byte[] iv = this.iv;

            int ivBytesLeft = this.ivBytesLeft;
            int ivPos = iv.Length - ivBytesLeft;

            if (ivBytesLeft >= count)
            {
                for (; posIn < end; posIn++, posOut++, ivPos++)
                {
                    int b = dataIn[posIn];
                    dataOut[posOut] = (byte)(b ^ iv[ivPos]);
                    dataIn[posIn] = (byte)b;
                }
                this.ivBytesLeft = iv.Length - ivPos;
                return count;
            }
            for (; ivPos < BLOCK_SIZE; posIn++, posOut++, ivPos++)
            {
                iv[ivPos] = dataOut[posOut] = (byte)(dataIn[posIn] ^ iv[ivPos]);
            }
            count -= ivBytesLeft;

            uint[] sbox1 = this.sbox1;
            uint[] sbox2 = this.sbox2;
            uint[] sbox3 = this.sbox3;
            uint[] sbox4 = this.sbox4;

            uint[] pbox = this.pbox;

            uint pbox00 = pbox[0];
            uint pbox01 = pbox[1];
            uint pbox02 = pbox[2];
            uint pbox03 = pbox[3];
            uint pbox04 = pbox[4];
            uint pbox05 = pbox[5];
            uint pbox06 = pbox[6];
            uint pbox07 = pbox[7];
            uint pbox08 = pbox[8];
            uint pbox09 = pbox[9];
            uint pbox10 = pbox[10];
            uint pbox11 = pbox[11];
            uint pbox12 = pbox[12];
            uint pbox13 = pbox[13];
            uint pbox14 = pbox[14];
            uint pbox15 = pbox[15];
            uint pbox16 = pbox[16];
            uint pbox17 = pbox[17];

            uint hi = (((uint)iv[0]) << 24) |
                      (((uint)iv[1]) << 16) |
                      (((uint)iv[2]) <<  8) |
                              iv[3];

            uint lo = (((uint)iv[4]) << 24) |
                      (((uint)iv[5]) << 16) |
                      (((uint)iv[6]) <<  8) |
                              iv[7];

            int rest = count % BLOCK_SIZE;
            end -= rest;

            for (; ; )
            {
                hi ^= pbox00;
                lo ^= (((sbox1[(int)(hi >> 24)] + sbox2[(int)((hi >> 16) & 0x0ff)]) ^ sbox3[(int)((hi >> 8) & 0x0ff)]) + sbox4[(int)(hi & 0x0ff)]) ^ pbox01;
                hi ^= (((sbox1[(int)(lo >> 24)] + sbox2[(int)((lo >> 16) & 0x0ff)]) ^ sbox3[(int)((lo >> 8) & 0x0ff)]) + sbox4[(int)(lo & 0x0ff)]) ^ pbox02;
                lo ^= (((sbox1[(int)(hi >> 24)] + sbox2[(int)((hi >> 16) & 0x0ff)]) ^ sbox3[(int)((hi >> 8) & 0x0ff)]) + sbox4[(int)(hi & 0x0ff)]) ^ pbox03;
                hi ^= (((sbox1[(int)(lo >> 24)] + sbox2[(int)((lo >> 16) & 0x0ff)]) ^ sbox3[(int)((lo >> 8) & 0x0ff)]) + sbox4[(int)(lo & 0x0ff)]) ^ pbox04;
                lo ^= (((sbox1[(int)(hi >> 24)] + sbox2[(int)((hi >> 16) & 0x0ff)]) ^ sbox3[(int)((hi >> 8) & 0x0ff)]) + sbox4[(int)(hi & 0x0ff)]) ^ pbox05;
                hi ^= (((sbox1[(int)(lo >> 24)] + sbox2[(int)((lo >> 16) & 0x0ff)]) ^ sbox3[(int)((lo >> 8) & 0x0ff)]) + sbox4[(int)(lo & 0x0ff)]) ^ pbox06;
                lo ^= (((sbox1[(int)(hi >> 24)] + sbox2[(int)((hi >> 16) & 0x0ff)]) ^ sbox3[(int)((hi >> 8) & 0x0ff)]) + sbox4[(int)(hi & 0x0ff)]) ^ pbox07;
                hi ^= (((sbox1[(int)(lo >> 24)] + sbox2[(int)((lo >> 16) & 0x0ff)]) ^ sbox3[(int)((lo >> 8) & 0x0ff)]) + sbox4[(int)(lo & 0x0ff)]) ^ pbox08;
                lo ^= (((sbox1[(int)(hi >> 24)] + sbox2[(int)((hi >> 16) & 0x0ff)]) ^ sbox3[(int)((hi >> 8) & 0x0ff)]) + sbox4[(int)(hi & 0x0ff)]) ^ pbox09;
                hi ^= (((sbox1[(int)(lo >> 24)] + sbox2[(int)((lo >> 16) & 0x0ff)]) ^ sbox3[(int)((lo >> 8) & 0x0ff)]) + sbox4[(int)(lo & 0x0ff)]) ^ pbox10;
                lo ^= (((sbox1[(int)(hi >> 24)] + sbox2[(int)((hi >> 16) & 0x0ff)]) ^ sbox3[(int)((hi >> 8) & 0x0ff)]) + sbox4[(int)(hi & 0x0ff)]) ^ pbox11;
                hi ^= (((sbox1[(int)(lo >> 24)] + sbox2[(int)((lo >> 16) & 0x0ff)]) ^ sbox3[(int)((lo >> 8) & 0x0ff)]) + sbox4[(int)(lo & 0x0ff)]) ^ pbox12;
                lo ^= (((sbox1[(int)(hi >> 24)] + sbox2[(int)((hi >> 16) & 0x0ff)]) ^ sbox3[(int)((hi >> 8) & 0x0ff)]) + sbox4[(int)(hi & 0x0ff)]) ^ pbox13;
                hi ^= (((sbox1[(int)(lo >> 24)] + sbox2[(int)((lo >> 16) & 0x0ff)]) ^ sbox3[(int)((lo >> 8) & 0x0ff)]) + sbox4[(int)(lo & 0x0ff)]) ^ pbox14;
                lo ^= (((sbox1[(int)(hi >> 24)] + sbox2[(int)((hi >> 16) & 0x0ff)]) ^ sbox3[(int)((hi >> 8) & 0x0ff)]) + sbox4[(int)(hi & 0x0ff)]) ^ pbox15;
                hi ^= (((sbox1[(int)(lo >> 24)] + sbox2[(int)((lo >> 16) & 0x0ff)]) ^ sbox3[(int)((lo >> 8) & 0x0ff)]) + sbox4[(int)(lo & 0x0ff)]) ^ pbox16;

                uint swap = lo ^ pbox17;
                lo = hi;
                hi = swap;

                if (posIn >= end)
                {
                    break;
                }

                uint chi = (((uint)dataIn[posIn]    ) << 24) |
                           (((uint)dataIn[posIn + 1]) << 16) |
                           (((uint)dataIn[posIn + 2]) <<  8) |
                                   dataIn[posIn + 3];
                
                uint clo = (((uint)dataIn[posIn + 4]) << 24) |
                           (((uint)dataIn[posIn + 5]) << 16) |
                           (((uint)dataIn[posIn + 6]) <<  8) |
                                   dataIn[posIn + 7];

                posIn += 8;

                hi ^= chi;
                lo ^= clo;

                dataOut[posOut]     = (byte)(hi >> 24);
                dataOut[posOut + 1] = (byte)(hi >> 16);
                dataOut[posOut + 2] = (byte)(hi >>  8);
                dataOut[posOut + 3] = (byte) hi;

                dataOut[posOut + 4] = (byte)(lo >> 24);
                dataOut[posOut + 5] = (byte)(lo >> 16);
                dataOut[posOut + 6] = (byte)(lo >>  8);
                dataOut[posOut + 7] = (byte) lo;

                posOut += 8;

                hi = chi;
                lo = clo;
            }

            iv[0] = (byte)(hi >> 24);
            iv[1] = (byte)(hi >> 16);
            iv[2] = (byte)(hi >>  8);
            iv[3] = (byte) hi;
            iv[4] = (byte)(lo >> 24);
            iv[5] = (byte)(lo >> 16);
            iv[6] = (byte)(lo >>  8);
            iv[7] = (byte) lo;

            for (int i = 0; i < rest; i++, posIn++, posOut++)
            {
                int b = dataIn[posIn];
                dataOut[posOut] = (byte)(b ^ iv[i]);
                iv[i] = (byte)b;
            }

            this.ivBytesLeft = iv.Length - rest;

            return count;
        }

        /// <see cref="BlowfishNET.BlowfishECB.Clone"/>
        public new object Clone()
        {
            BlowfishCFB result;

            result = new BlowfishCFB();

            result.pbox = (uint[])this.pbox.Clone();

            result.sbox1 = (uint[])this.sbox1.Clone();
            result.sbox2 = (uint[])this.sbox2.Clone();
            result.sbox3 = (uint[])this.sbox3.Clone();
            result.sbox4 = (uint[])this.sbox4.Clone();

            result.block = (byte[])this.block.Clone();

            result.isWeakKey = this.isWeakKey;

            result.iv = (byte[])this.iv.Clone();

            return result;
        }
    }
}