Java对称加密编码：IDEA

原作者：http://jatula.iteye.com/blog/315449
package
 cn.lake.util;

/**
 * Java对称加密编码：IDEA
 *
 * @author lake_xie
 *
 */
class
 IDEADemo {

    /* 源数据 */
    private
 
byte
 m_string[];
    /* 目标数据 */
    private
 
byte
 c_string[];
    /* 密钥 */
    private
 
byte
 k_string[];
    /* 数据块 1, 2, 3, 4 */
    private
 
char
 X1, X2, X3, X4;
    /* 加密子密钥 */
    private
 
char
 Z[];
    /* 解密子密钥 */
    private
 
char
 Z_1[];
    /*   */
    private
 
char
 temp1, temp2, temp3, temp4, temp5;
    private
 
char
 temp6, temp7, temp8, temp9, temp10;

    /* 初始化 */
    IDEADemo() {
        m_string = new
 
byte
[
8
];
        c_string = new
 
byte
[
8
];
        k_string = new
 
byte
[
16
];
        Z = new
 
char
[
53
];
        Z_1 = new
 
char
[
53
];
    }

    /*   */
    private
 
char
 inv(
char
 x) {
        char
 t0, t1, q, y;
        if
 (x <= 
1
)
            return
 x; 
/* 0 and 1 are self-inverse */
        t1 = (char
) (
0x10001
 / x);
        /* Since x >= 2, this fits into 16 bits */
        y = (char
) (
0x10001
 % x);
        if
 (y == 
1
)
            return
 (
char
) (
1
 - t1);
        t0 = 1
;
        do
 {
            q = (char
) (x / y);
            x = (char
) (x % y);
            t0 += (char
) (q * t1);
            if
 (x == 
1
)
                return
 t0;
            q = (char
) (y / x);
            y = (char
) (y % x);
            t1 += (char
) (q * t0);
        } while
 (y != 
1
);
        return
 (
char
) (
1
 - t1);
    }

    /*   */
    private
 
char
 multiply(
char
 input1, 
char
 input2) {
        long
 p = input1 * input2;
        if
 (p == 
0
)
            input2 = (char
) (
65537
 - input1 - input2);
        else
 {
            input1 = (char
) (p >> 
16
);
            input2 = (char
) p;
            input1 = (char
) (input2 - input1);

            if
 (input2 < input1)
                input1 += 65537
;
        }
        return
 input1;
    }

    /*   */
    private
 
void
 Separate_m_2_X() {
        // 本函数的目的是从m string中得到X1,X2,X3,X4
        // get X1,X2,X3,X4 from m string
        char
 temp;

        X1 = (char
) m_string[
0
];
        X1 <<= 8
;
        temp = (char
) m_string[
1
];
        temp &= 0xFF
;
        X1 |= temp;

        X2 = (char
) m_string[
2
];
        X2 <<= 8
;
        temp = (char
) m_string[
3
];
        temp &= 0xFF
;
        X2 |= temp;

        X3 = (char
) m_string[
4
];
        X3 <<= 8
;
        temp = (char
) m_string[
5
];
        temp &= 0xFF
;
        X3 |= temp;

        X4 = (char
) m_string[
6
];
        X4 <<= 8
;
        temp = (char
) m_string[
7
];
        temp &= 0xFF
;
        X4 |= temp;
    }

    /**
     * 设置密钥
     *
     * @param input_k_string
     *            input the 128bit key(16 byte)
     * @return No return value
     */
    void
 Set_k(
byte
[] input_k_string) {
        // 本函数的目的是设置密钥
        for
 (
int
 i = 
0
; i <= 
15
; i++)
            k_string[i] = input_k_string[i];
    }

    /**
     * 加密用子密钥运算
     *
     * @param No
     *            param
     * @return No return value
     */
    void
 Creat_encrypt_sub_k() {
        // 本函数的目的是生成加密子密钥
        // creat encrypt sub key and store to Z[57]
        char
 temp;
        byte
 temp1, temp2, temp3;
        int
 i;
        int
 num;
        for
 (num = 
0
; num <= 
6
; num++) {
            Z[1
 + num * 
8
] = (
char
) k_string[
0
];
            Z[1
 + num * 
8
] <<= 
8
;
            temp = (char
) k_string[
1
];
            temp = (char
) (temp & 
0x00FF
);
            Z[1
 + num * 
8
] |= temp;

            Z[2
 + num * 
8
] = (
char
) k_string[
2
];
            Z[2
 + num * 
8
] <<= 
8
;
            temp = (char
) k_string[
3
];
            temp = (char
) (temp & 
0x00FF
);
            Z[2
 + num * 
8
] |= temp;

            Z[3
 + num * 
8
] = (
char
) k_string[
4
];
            Z[3
 + num * 
8
] <<= 
8
;
            temp = (char
) k_string[
5
];
            temp = (char
) (temp & 
0x00FF
);
            Z[3
 + num * 
8
] |= temp;

            Z[4
 + num * 
8
] = (
char
) k_string[
6
];
            Z[4
 + num * 
8
] <<= 
8
;
            temp = (char
) k_string[
7
];
            temp = (char
) (temp & 
0x00FF
);
            Z[4
 + num * 
8
] |= temp;
            if
 (num != 
6
) {
                Z[5
 + num * 
8
] = (
char
) k_string[
8
];
                Z[5
 + num * 
8
] <<= 
8
;
                temp = (char
) k_string[
9
];
                temp = (char
) (temp & 
0x00FF
);
                Z[5
 + num * 
8
] |= temp;
            }
            if
 (num != 
6
) {
                Z[6
 + num * 
8
] = (
char
) k_string[
10
];
                Z[6
 + num * 
8
] <<= 
8
;
                temp = (char
) k_string[
11
];
                temp = (char
) (temp & 
0x00FF
);
                Z[6
 + num * 
8
] |= temp;
            }
            if
 (num != 
6
) {
                Z[7
 + num * 
8
] = (
char
) k_string[
12
];
                Z[7
 + num * 
8
] <<= 
8
;
                temp = (char
) k_string[
13
];
                temp = (char
) (temp & 
0x00FF
);
                Z[7
 + num * 
8
] |= temp;
            }
            if
 (num != 
6
) {
                Z[8
 + num * 
8
] = (
char
) k_string[
14
];
                Z[8
 + num * 
8
] <<= 
8
;
                temp = (char
) k_string[
15
];
                temp = (char
) (temp & 
0x00FF
);
                Z[8
 + num * 
8
] |= temp;
            }

            // now,start to left move 25 bit
            // first left move 24 bit
            temp1 = k_string[0
];
            temp2 = k_string[1
];
            temp3 = k_string[2
];
            for
 (i = 
0
; i <= 
12
; i++)
                k_string[i] = k_string[i + 3
];
            k_string[13
] = temp1;
            k_string[14
] = temp2;
            k_string[15
] = temp3;

            // then left move 1 bit,sum 25 bit
            byte
 store_bit[] = 
new
 
byte
[
16
]; 
// store k_strings first bit.
            for
 (i = 
15
; i >= 
0
; i--) {
                // from high bit to low
                store_bit[i] = (byte
) (k_string[i] >> 
7
);
                store_bit[i] &= 0x01
;
                k_string[i] <<= 1
;
                if
 (i != 
15
)
                    k_string[i] += store_bit[i + 1
];
            }
            k_string[15
] += store_bit[
0
];
            // complete to left move 25 bit
        } // All encrypt sub key created
    }

    /**
     * 解密子密钥计算
     *
     * @param No
     *            param
     * @return No return value
     */
    void
 Creat_decrypt_sub_k() {
        // 本函数的目的是生成解密子密钥
        Z_1[1
] = inv(Z[
49
]);
        Z_1[2
] = (
char
) (
0
 - Z[
50
]);
        Z_1[3
] = (
char
) (
0
 - Z[
51
]);
        Z_1[4
] = inv(Z[
52
]);
        Z_1[5
] = (
char
) (Z[
47
]);
        Z_1[6
] = Z[
48
];

        for
 (
int
 i = 
1
; i <= 
7
; i++) {
            Z_1[1
 + i * 
6
] = inv(Z[
49
 - i * 
6
]);
            Z_1[2
 + i * 
6
] = (
char
) (
0
 - Z[
51
 - i * 
6
]);
            Z_1[3
 + i * 
6
] = (
char
) (
0
 - Z[
50
 - i * 
6
]);
            Z_1[4
 + i * 
6
] = inv(Z[
52
 - i * 
6
]);
            Z_1[5
 + i * 
6
] = Z[
47
 - i * 
6
];
            Z_1[6
 + i * 
6
] = Z[
48
 - i * 
6
];
        }
        Z_1[49
] = inv(Z[
1
]);
        Z_1[50
] = (
char
) (
0
 - Z[
2
]);
        Z_1[51
] = (
char
) (
0
 - Z[
3
]);
        Z_1[52
] = inv(Z[
4
]);
    }

    /**
     * 设置源数据
     *
     * @param input_m_string
     *            input the source data to be processed
     * @return No return value
     */
    void
 Set_m(
byte
[] input_m_string) {
        // 本函数的目的是设置源数据
        for
 (
int
 i = 
0
; i <= 
7
; i++)
            m_string[i] = input_m_string[i];
    }

    /**
     * 加密运算
     *
     * @param No
     *            param
     * @return No return value
     */
    void
 Encrypt() {
        // 本函数的目的是加密

        // 把m分成X1,X2,X3,X4
        Separate_m_2_X();

        // 下面做8圈叠代
        for
 (
int
 num = 
0
; num <= 
7
; num++) {
            temp1 = multiply(Z[1
 + num * 
6
], X1); 
// 1
            temp2 = (char
) (X2 + Z[
2
 + num * 
6
]); 
// 2
            temp3 = (char
) (X3 + Z[
3
 + num * 
6
]); 
// 3
            temp4 = multiply(Z[4
 + num * 
6
], X4); 
// 4
            temp5 = (char
) (temp1 ^ temp3); 
// 5
            temp6 = (char
) (temp2 ^ temp4); 
// 6
            temp7 = multiply(Z[5
 + num * 
6
], temp5); 
// 7
            temp8 = (char
) (temp7 + temp6);
            temp10 = multiply(Z[6
 + num * 
6
], temp8);
            temp9 = (char
) (temp7 + temp10);

            X1 = (char
) (temp1 ^ temp10);
            if
 (num != 
7
) {
                X2 = (char
) (temp3 ^ temp10);
                X3 = (char
) (temp2 ^ temp9);
            } else
 {
                X2 = (char
) (temp2 ^ temp9);
                X3 = (char
) (temp3 ^ temp10);
            }
            X4 = (char
) (temp4 ^ temp9);
        } // end of 8 times

        // 输出变换
        X1 = multiply(Z[49
], X1);
        X2 += Z[50
];
        X3 += Z[51
];
        X4 = multiply(Z[52
], X4);

        // 把X1,X2,X3,X4复制到c_string中。
        // now,creat c_string from X1..X4;
        c_string[1
] = (
byte
) X1;
        c_string[0
] = (
byte
) (X1 >> 
8
);
        c_string[3
] = (
byte
) X2;
        c_string[2
] = (
byte
) (X2 >> 
8
);
        c_string[5
] = (
byte
) X3;
        c_string[4
] = (
byte
) (X3 >> 
8
);
        c_string[7
] = (
byte
) X4;
        c_string[6
] = (
byte
) (X4 >> 
8
);

        // end of encryption
    }

    /**
     * 解密运算
     *
     * @param No
     *            param
     * @return No return value
     */
    void
 Decrypt() { 
// 本函数的目的是解密

        // 把m分成X1,X2,X3,X4
        Separate_m_2_X();

        // 下面做8圈叠代
        for
 (
int
 num = 
0
; num <= 
7
; num++) {
            temp1 = multiply(Z_1[1
 + num * 
6
], X1); 
// 1
            temp2 = (char
) (X2 + Z_1[
2
 + num * 
6
]); 
// 2
            temp3 = (char
) (X3 + Z_1[
3
 + num * 
6
]); 
// 3
            temp4 = multiply(Z_1[4
 + num * 
6
], X4); 
// 4
            temp5 = (char
) (temp1 ^ temp3); 
// 5
            temp6 = (char
) (temp2 ^ temp4); 
// 6
            temp7 = multiply(Z_1[5
 + num * 
6
], temp5); 
// 7
            temp8 = (char
) (temp7 + temp6);
            temp10 = multiply(Z_1[6
 + num * 
6
], temp8);
            temp9 = (char
) (temp7 + temp10);

            X1 = (char
) (temp1 ^ temp10);
            if
 (num != 
7
) {
                X2 = (char
) (temp3 ^ temp10);
                X3 = (char
) (temp2 ^ temp9);
            } else
 {
                X2 = (char
) (temp2 ^ temp9);
                X3 = (char
) (temp3 ^ temp10);
            }
            X4 = (char
) (temp4 ^ temp9);
        } // end of 8 times

        // 输出变换
        X1 = multiply(Z_1[49
], X1);
        X2 += Z_1[50
];
        X3 += Z_1[51
];
        X4 = multiply(Z_1[52
], X4);

        // 把X1,X2,X3,X4复制到c_string中。
        // now,creat c_string from X1..X4;
        c_string[1
] = (
byte
) X1;
        c_string[0
] = (
byte
) (X1 >> 
8
);
        c_string[3
] = (
byte
) X2;
        c_string[2
] = (
byte
) (X2 >> 
8
);
        c_string[5
] = (
byte
) X3;
        c_string[4
] = (
byte
) (X3 >> 
8
);
        c_string[7
] = (
byte
) X4;
        c_string[6
] = (
byte
) (X4 >> 
8
);
        // end of decryption
    }

    /**
     * 结果输出
     *
     * @param output_c_string
     *            output the result
     * @return No return value
     */
    void
 Get_c(
byte
[] output_c_string) {
        // 本函数的目的是获得目标数据
        for
 (
int
 i = 
0
; i <= 
7
; i++)
            output_c_string[i] = c_string[i];
    }

    public
 
static
 
void
 main(String[] args) {
        int
 i;
        IDEADemo demoTest = new
 IDEADemo();
        byte
[] m = { 
1
, 
2
, 
3
, 
4
, 
5
, 
6
, 
7
, 
8
, 
9
 };
        byte
[] k = { 
9
, 
8
, 
7
, 
6
, 
5
, 
4
, 
3
, 
2
, 
1
, 
0
, 
1
, 
2
, 
3
, 
4
, 
5
, 
6
 };
        byte
[] c = 
new
 
byte
[
8
];
        demoTest.Set_k(k);
        demoTest.Creat_encrypt_sub_k();
        demoTest.Creat_decrypt_sub_k();
        System.out.println("密钥:"
);
        for
 (i = 
0
; i <= 
15
; i++)
            System.out.print(k[i]);
        System.out.println(""
);

        demoTest.Set_m(m);
        System.out.println("明文:"
);
        for
 (i = 
0
; i <= 
7
; i++)
            System.out.print(m[i]);
        System.out.println(""
);

        demoTest.Encrypt();
        demoTest.Get_c(c);
        System.out.println("密文:"
);
        for
 (i = 
0
; i <= 
7
; i++)
            System.out.print((int
) (c[i]) + 
"   "
);
        System.out.println(""
);

        demoTest.Set_m(c);
        demoTest.Decrypt();
        demoTest.Get_c(c);
        System.out.println("解密后明文:"
);
        for
 (i = 
0
; i <= 
7
; i++)
            System.out.print(c[i]);
        System.out.println(""
);

        System.out.println("hello!"
);
    }
}