Beispiel #1
0
        public static int[,] GetKeyExpansion(string str)
        {
            str = str.ToLower();
            byte[]        buf = Encoding.UTF8.GetBytes(str);
            StringBuilder s   = new StringBuilder(128);

            int nb = 4;
            int nk = buf.Length / 4;
            int nr = 0;

            switch (nk)
            {
            case 4: nr = 10;
                break;

            case 6: nr = 12;
                break;

            case 8: nr = 14;
                break;
            }
            int[,] key       = new int[nb * (nr + 1), nb];
            int[,] cipherKey = new int[nr + 1, 16];
            int[] temp = new int[4];

            for (int i = 0; i < buf.Length; i++)
            {
                for (int j = 7; j >= 0; j--)
                {
                    s = s.Append(buf[i] >> j & 1);
                }
            }
            for (int i = 0; i < nk; i++)
            {
                for (int j = 0; j < nb; j++)
                {
                    key[i, j] = Convert.ToInt32(s.ToString(8 * j + i * 32, 8), 2);
                }
            }
            for (int i = nk; i < nb * (nr + 1); i++)
            {
                temp[0] = key[i - 1, 0];
                temp[1] = key[i - 1, 1];
                temp[2] = key[i - 1, 2];
                temp[3] = key[i - 1, 3];
                for (int j = 0; j < nb; j++)
                {
                    if (i % nk == 0)
                    {
                        temp[j] = SubBytes.GetSubByte(key[i - 1, (j + 1) % 4]) ^ Rcon[i / nk, j];
                    }
                    else if ((nk > 6) && (i % nk == 4))
                    {
                        temp[j] = SubBytes.GetSubByte(key[i - 1, j]);
                    }
                    key[i, j] = temp[j] ^ key[i - nk, j];
                }
            }
            for (int i = 0; i < nr + 1; i++)
            {
                for (int j = 0; j < 16; j++)
                {
                    cipherKey[i, j] = key[j / 4 + i * 4, j % 4];
                }
            }
            return(cipherKey);
        }
Beispiel #2
0
        public static string Encrypt(string Source, string Key, byte KeyLengthChoiced = 16)
        {
            if (String.IsNullOrEmpty(Source))
            {
                throw new Exception("没有输入明文!");
            }

            int KeyByteLength = Encoding.Default.GetBytes(Key).Length;

            switch (KeyLengthChoiced)
            {
            case 16:
            {
                if (KeyByteLength != 16)
                {
                    throw new Exception("密钥必须为16个字符或8个汉字!");
                }
                break;
            }

            case 24:
            {
                if (KeyByteLength != 24)
                {
                    throw new Exception("密钥必须为24个字符或12个汉字!");
                }
                break;
            }

            case 32:
            {
                if (KeyByteLength != 32)
                {
                    throw new Exception("密钥必须为32个字符或16个汉字!");
                }
                break;
            }

            default:
            {
                throw new Exception("所选密钥位数错误,请选择16、24或32位密匙");
            }
            }

            int[,] key    = KeyExpansion.GetKeyExpansion(Key);
            int[,] cipher = Encryption.Getencryption(Source, key);
            StringBuilder strB = new StringBuilder();

            for (int i = 0; i < cipher.GetLength(0); i++)
            {
                for (int j = 0; j < 16; j++)
                {
                    StringBuilder s   = new StringBuilder();
                    byte[]        buf = new byte[2];
                    s      = SubBytes.GetStr(cipher[i, j]);
                    buf[0] = Convert.ToByte(s.ToString(0, 4), 2);
                    buf[1] = Convert.ToByte(s.ToString(4, 4), 2);
                    strB.Append(alphabet[buf[0]] + "" + alphabet[buf[1]]);
                }
            }
            return(strB.ToString());
        }
Beispiel #3
0
        public static int[,] Getencryption(string str, int[,] key)
        {
            str = str.ToLower();
            StringBuilder strB = new StringBuilder(str);

            if (strB.Length % 16 != 0)
            {
                int len = strB.Length;
                for (int i = 0; i < 32 - len % 32; i++)
                {
                    strB = strB.Append(" ");
                }
            }
            byte[] buf = Encoding.UTF8.GetBytes(strB.ToString());

            int[] cipherkey = new int[16];
            int[,] plain      = new int[buf.Length / 16, 16];
            int[,] ciphertext = new int[buf.Length / 16, 16];
            int[] plaintext = new int[16];

            StringBuilder s = new StringBuilder(100000);

            for (int i = 0; i < buf.Length; i++)
            {
                for (int j = 7; j >= 0; j--)
                {
                    s = s.Append(buf[i] >> j & 1);
                }
            }
            for (int i = 0; i < plain.GetLength(0); i++)
            {
                for (int j = 0; j < 16; j++)
                {
                    plain[i, j] = Convert.ToInt32(s.ToString(j * 8 + i * 128, 8), 2);
                }
            }
            for (int i = 0; i < plain.GetLength(0); i++)
            {
                for (int h = 0; h < 16; h++)
                {
                    cipherkey[h] = key[0, h];
                    plaintext[h] = plain[i, h];
                }
                plaintext = AddRoundKey(plaintext, cipherkey);
                for (int j = 0; j < key.GetLength(0) - 2; j++)
                {
                    for (int h = 0; h < 16; h++)
                    {
                        cipherkey[h] = key[j + 1, h];
                    }
                    for (int h = 0; h < plaintext.Length; h++)
                    {
                        plaintext[h] = SubBytes.GetSubByte(plaintext[h]);
                    }
                    plaintext = ShiftRows(plaintext);
                    plaintext = MixColumn.GetMixColumn(plaintext);
                    plaintext = AddRoundKey(plaintext, cipherkey);
                }
                for (int h = 0; h < 16; h++)
                {
                    cipherkey[h] = key[key.GetLength(0) - 1, h];
                }
                for (int h = 0; h < plaintext.Length; h++)
                {
                    plaintext[h] = SubBytes.GetSubByte(plaintext[h]);
                }
                plaintext = ShiftRows(plaintext);
                plaintext = AddRoundKey(plaintext, cipherkey);
                for (int j = 0; j < 16; j++)
                {
                    ciphertext[i, j] = plaintext[j];
                }
            }
            return(ciphertext);
        }
Beispiel #4
0
        public static int[,] Getdecryption(string str, int[,] key)
        {
            int[] cipherkey = new int[16];
            str = str.ToLower();
            char[] ch = str.ToCharArray();

            int[,] cipher = new int[str.Length / 32, 16];
            int[,] plian  = new int[str.Length / 32, 16];
            int[] plaintext = new int[16];

            StringBuilder s = new StringBuilder(100000);

            for (int i = 0; i < str.Length; i++)
            {
                for (int j = 3; j >= 0; j--)
                {
                    s = s.Append(Decryption.GetNum(ch[i]) >> j & 1);
                }
            }
            for (int i = 0; i < cipher.GetLength(0); i++)
            {
                for (int j = 0; j < 16; j++)
                {
                    cipher[i, j] = Convert.ToInt32(s.ToString(j * 8 + i * 128, 8), 2);
                }
            }

            for (int i = 0; i < cipher.GetLength(0); i++)
            {
                for (int h = 0; h < 16; h++)
                {
                    cipherkey[h] = key[key.GetLength(0) - 1, h];
                    plaintext[h] = cipher[i, h];
                }
                plaintext = AddRoundKey(plaintext, cipherkey);
                for (int j = key.GetLength(0) - 2; j > 0; j--)
                {
                    for (int h = 0; h < 16; h++)
                    {
                        cipherkey[h] = key[j, h];
                    }
                    for (int h = 0; h < plaintext.Length; h++)
                    {
                        plaintext[h] = SubBytes.GetByteSub(plaintext[h]);
                    }
                    plaintext = InvShiftRows(plaintext);
                    plaintext = MixColumn.InvMixColumn(plaintext);
                    plaintext = AddRoundKey(plaintext, cipherkey);
                }
                for (int h = 0; h < 16; h++)
                {
                    cipherkey[h] = key[0, h];
                }
                for (int h = 0; h < plaintext.Length; h++)
                {
                    plaintext[h] = SubBytes.GetByteSub(plaintext[h]);
                }
                plaintext = InvShiftRows(plaintext);
                plaintext = AddRoundKey(plaintext, cipherkey);
                for (int j = 0; j < 16; j++)
                {
                    plian[i, j] = plaintext[j];
                }
            }
            return(plian);
        }