無線區域網產品使用的SMS4密碼演算法及其實現

cnbragon發表於2007-02-24
密碼演算法

SMS4演算法由國家商用密碼管理辦公室釋出，其演算法的介紹可以從國家商用密碼管理辦公室的網站上下載到：

http://www.oscca.gov.cn/Doc/6/News_1106.htm

我花了點時間，簡單的實現了這個演算法，程式碼如下：

 其中有不少程式碼是可以進一步最佳化以提高速度的，比如 i%4 => i&3 ; i*8 =>  i << 3

#include <stdio.h>

#define ROUND            32

static unsigned long FK[4]={
    0xA3B1BAC6,0x56AA3350,0x677D9197,0xB27022DC
};

static unsigned long CK[ROUND]={
    0x00070e15, 0x1c232a31, 0x383f464d, 0x545b6269,
    0x70777e85, 0x8c939aa1, 0xa8afb6bd, 0xc4cbd2d9,
    0xe0e7eef5, 0xfc030a11, 0x181f262d, 0x343b4249,
    0x50575e65, 0x6c737a81, 0x888f969d, 0xa4abb2b9,
    0xc0c7ced5, 0xdce3eaf1, 0xf8ff060d, 0x141b2229,
    0x30373e45, 0x4c535a61, 0x686f767d, 0x848b9299,
    0xa0a7aeb5, 0xbcc3cad1, 0xd8dfe6ed, 0xf4fb0209,
    0x10171e25, 0x2c333a41, 0x484f565d, 0x646b7279
};

static unsigned char Sbox[256]={
    0xd6,0x90,0xe9,0xfe,0xcc,0xe1,0x3d,0xb7,0x16,0xb6,0x14,0xc2,0x28,0xfb,0x2c,0x05,
    0x2b,0x67,0x9a,0x76,0x2a,0xbe,0x04,0xc3,0xaa,0x44,0x13,0x26,0x49,0x86,0x06,0x99,
    0x9c,0x42,0x50,0xf4,0x91,0xef,0x98,0x7a,0x33,0x54,0x0b,0x43,0xed,0xcf,0xac,0x62,
    0xe4,0xb3,0x1c,0xa9,0xc9,0x08,0xe8,0x95,0x80,0xdf,0x94,0xfa,0x75,0x8f,0x3f,0xa6,
    0x47,0x07,0xa7,0xfc,0xf3,0x73,0x17,0xba,0x83,0x59,0x3c,0x19,0xe6,0x85,0x4f,0xa8,
    0x68,0x6b,0x81,0xb2,0x71,0x64,0xda,0x8b,0xf8,0xeb,0x0f,0x4b,0x70,0x56,0x9d,0x35,
    0x1e,0x24,0x0e,0x5e,0x63,0x58,0xd1,0xa2,0x25,0x22,0x7c,0x3b,0x01,0x21,0x78,0x87,
    0xd4,0x00,0x46,0x57,0x9f,0xd3,0x27,0x52,0x4c,0x36,0x02,0xe7,0xa0,0xc4,0xc8,0x9e,
    0xea,0xbf,0x8a,0xd2,0x40,0xc7,0x38,0xb5,0xa3,0xf7,0xf2,0xce,0xf9,0x61,0x15,0xa1,
    0xe0,0xae,0x5d,0xa4,0x9b,0x34,0x1a,0x55,0xad,0x93,0x32,0x30,0xf5,0x8c,0xb1,0xe3,
    0x1d,0xf6,0xe2,0x2e,0x82,0x66,0xca,0x60,0xc0,0x29,0x23,0xab,0x0d,0x53,0x4e,0x6f,
    0xd5,0xdb,0x37,0x45,0xde,0xfd,0x8e,0x2f,0x03,0xff,0x6a,0x72,0x6d,0x6c,0x5b,0x51,
    0x8d,0x1b,0xaf,0x92,0xbb,0xdd,0xbc,0x7f,0x11,0xd9,0x5c,0x41,0x1f,0x10,0x5a,0xd8,
    0x0a,0xc1,0x31,0x88,0xa5,0xcd,0x7b,0xbd,0x2d,0x74,0xd0,0x12,0xb8,0xe5,0xb4,0xb0,
    0x89,0x69,0x97,0x4a,0x0c,0x96,0x77,0x7e,0x65,0xb9,0xf1,0x09,0xc5,0x6e,0xc6,0x84,
    0x18,0xf0,0x7d,0xec,0x3a,0xdc,0x4d,0x20,0x79,0xee,0x5f,0x3e,0xd7,0xcb,0x39,0x48
};

#define ROL(x,y)    ((x)<<(y) |    (x)>>(32-(y)))

unsigned long T1(unsigned long    dwA)
{
    unsigned char    a0[4]={0};
    unsigned char    b0[4]={0};
    unsigned long    dwB=0;
    unsigned long    dwC=0;
    int                i=0;

    for (i=0;i<4;i++)
    {
        a0[i]    =    (dwA>>(i*8))        &    0xff;
        b0[i]    =    Sbox[a0[i]];
        dwB        |=    (b0[i]<<(i*8));
    }

    dwC=dwB^ROL(dwB,2)^ROL(dwB,10)^ROL(dwB,18)^ROL(dwB,24);

    return dwC;
}

unsigned long T2(unsigned long    dwA)
{
    unsigned char    a0[4]={0};
    unsigned char    b0[4]={0};
    unsigned long    dwB=0;
    unsigned long    dwC=0;
    int        i=0;

    for (i=0;i<4;i++)
    {
        a0[i]    =    (dwA>>(i*8))        &    0xff;
        b0[i]    =    Sbox[a0[i]];
        dwB        |=    (b0[i]<<(i*8));
    }

    dwC=dwB^ROL(dwB,13)^ROL(dwB,23);

    return dwC;
}

/* MK[4] is the Encrypt Key, rk[32] is Round Key */
void Key_Expansion(unsigned long MK[],    unsigned long rk[])
{
    unsigned long    K[4]={0};
    int        i=0;

    for (i=0;i<4;i++)
    {
        K[i]    =    MK[i]    ^    FK[i];
    }

    for (i=0;i<ROUND;i++)
    {
        K[i%4]^=T2(K[(i+1)%4]^K[(i+2)%4]^K[(i+3)%4]^CK[i]);
        rk[i]=K[i%4];
    }
}

/* X[4] is PlainText, rk[32] is round Key, Y[4] is CipherText */
void ECB_Encryption(unsigned long X[], unsigned long rk[], unsigned long Y[])
{
    unsigned long    tempX[4]={0};
    int                i=0;
    
    for (i=0;i<4;i++)
    {
        tempX[i]=X[i];
    }

    for (i=0;i<ROUND;i++)
    {
        tempX[i%4]^=T1(tempX[(i+1)%4]^tempX[(i+2)%4]^tempX[(i+3)%4]^rk[i]);
    }

    for (i=0;i<4;i++)
    {
        Y[i]=tempX[3-i];
    }
}

/* X[4] is PlainText, rk[32] is round Key, Y[4] is CipherText */
void ECB_Decryption(unsigned long X[], unsigned long rk[], unsigned long Y[])
{
    unsigned long    tempX[4]={0};
    int                i=0;
    
    for (i=0;i<4;i++)
    {
        tempX[i]=X[i];
    }

    for (i=0;i<ROUND;i++)
    {
        tempX[i%4]^=T1(tempX[(i+1)%4]^tempX[(i+2)%4]^tempX[(i+3)%4]^rk[(31-i)]);
    }

    for (i=0;i<4;i++)
    {
        Y[i]=tempX[3-i];
    }
}

void main()
{
    unsigned long key[4]={0x01234567,0x89abcdef,0xfedcba98,0x76543210};
    unsigned long roundkey[32]={0};
    unsigned long plaintext[4]={0x01234567,0x89abcdef,0xfedcba98,0x76543210};
    unsigned long ciphertext[4]={0};
    unsigned long test[4]={0};
    int    i=0;
    int j=0;

    Key_Expansion(key,roundkey);

    for (i=0;i<ROUND;i++)
    {
        printf("rk[ %d ] = %08x ", i,roundkey[i]);
    }
    
    printf("Encrypt: ");
    ECB_Encryption(plaintext,roundkey,ciphertext);
    for (i=0;i<4;i++)
    {
        printf("X[ %d ] = %08x ", i,ciphertext[i]);
    }

    printf("Decrypt: ");
    ECB_Decryption(ciphertext,roundkey,test);
    for (i=0;i<4;i++)
    {
        printf("X[ %d ] = %08x ", i,test[i]);
    }

    printf("Encrypt 1000000 times: ");
    for (i=0;i<1000000;i++)
    {
        ECB_Encryption(plaintext,roundkey,ciphertext);
        for (j=0;j<4;j++)
        {
            plaintext[j]=ciphertext[j];
        }
    }

    for (i=0;i<4;i++)
    {
        printf("Y[ %d ] = %08x ",i,ciphertext[i]);
    }
}

 

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