SHA-1（安全哈希算法实现）

如题，不知道sha-1的自己百度吧。

#include <iostream>
#include <vector>   //定义vector数组
#include <string>   //记录消息
using namespace std;

const int NUM = 8;   //一个字由32比特(或者8个16进制数)
const int BIT = 512;  //消息认证码要以512比特一组

//字常量
string H0 = "67452301";
string H1 = "EFCDAB89";
string H2 = "98BADCFE";
string H3 = "10325476";
string H4 = "C3D2E1F0";

//定义SHA1(安全哈希算法)类
class SHA1
{
public:
    //将一个字符串形式的字转化为vector数组
    vector<int> hex_into_dec(string word);

    //将vector转化为string字符串形式
    string num_into_message(vector<int> A);

    //两个字X和Y的逻辑"和"
    vector<int> word_AND(vector<int> A,vector<int> B);

    //两个字X和Y的逻辑"或"
    vector<int> word_OR(vector<int> A,vector<int> B);

    //两个字X和Y的逻辑"异或"
    vector<int> word_XOR(vector<int> A,vector<int> B);

    //两个字X和Y的逻辑"补"
    vector<int> word_COMPLEMENT(vector<int> A);

    //两个字X和Y的摸2^32整数加
    vector<int> word_ADD(vector<int> A,vector<int> B);

    //将字X循环左移s个位置
    vector<int> ROTL(vector<int> A,int s);

    //SHA-1的填充方案,我们设定msg由ASCII码组成
    vector<vector<int> > SHA_1_PAD(string msg);

    //将SHA-1压成以字为单位
    vector<vector<vector<int> > > compress(vector<vector<int> > result);

    //定义ft函数，每个ft函数都有B,C,D三个字作为输入，并产生一个字作为输出
    vector<int> Ft(int t,vector<int> B,vector<int> C,vector<int> D);

    //定义字常数K
    vector<int> K(int t);

    //开始进行SHA-1(安全Hash算法)的加密
    vector<vector<int> > SHA_1(string msg);

};

//将vector转化为string字符串形式
string SHA1::num_into_message(vector<int> A)
{
    int i;
    string msg = "";
    for(i = 0;i < A.size();i++)
    {
        if(A[i] >= 0 && A[i] <= 9)
            msg += '0' + A[i];
        else if(A[i] >= 10 && A[i] <= 15)
            msg += 'A' + (A[i] - 10);
    }
    return msg;
}

//将一个字符串形式的字转化为vector数组
vector<int> SHA1::hex_into_dec(string word)
{
    int i;
    vector<int> result(NUM,0);
    for(i = 0;i < NUM;i++)
    {
        if(word[i] >= '0' && word[i] <= '9')
        {
            result[i] = word[i] - '0';
        }
        else if(word[i] >= 'A' && word[i] <= 'F')
        {
            result[i] = 10 + word[i] - 'A';
        }
    }
    return result;
}

//两个字X和Y的逻辑"和"
vector<int> SHA1::word_AND(vector<int> A,vector<int> B)
{
    vector<int> result(NUM,0);
    int i;
    for(i = 0;i < NUM;i++)
    {
        result[i] = A[i] & B[i];
    }
    return result;
}

//两个字X和Y的逻辑"或"
vector<int> SHA1::word_OR(vector<int> A,vector<int> B)
{
    vector<int> result(NUM,0);
    int i;
    for(i = 0;i < NUM;i++)
    {
        result[i] = A[i] | B[i];
    }
    return result;
}

//两个字X和Y的逻辑"异或"
vector<int> SHA1::word_XOR(vector<int> A,vector<int> B)
{
    vector<int> result(NUM,0);
    int i;
    for(i = 0;i < NUM;i++)
    {
        result[i] = A[i] ^ B[i];
    }
    return result;
}

//两个字X和Y的逻辑"补"
vector<int> SHA1::word_COMPLEMENT(vector<int> A)
{
    vector<int> result(NUM,0);
    int i;
    for(i = 0;i < NUM;i++)
    {
        result[i] = 15 - A[i];
    }
    return result;
}

//两个字X和Y的摸2^32整数加
vector<int> SHA1::word_ADD(vector<int> A,vector<int> B)
{
    vector<int> result(NUM,0);
    int i;
    for(i = NUM - 1;i >= 0;i--)
    {
        result[i] = A[i] + B[i];
        if(i != 0)
        {
            int temp = result[i] / 16;
            result[i-1] += temp;
        }
        result[i] %= 16;
    }
    return result;
}

//将字X循环左移s个位置
vector<int> SHA1::ROTL(vector<int> A,int s)
{
    vector<int> result = A;
    vector<int> temp(NUM,0);
    int i,j;
    for(i = 0;i < s;i++)
    {
        for(j = NUM - 1;j >= 0;j--)
        {
            if(result[j] / 8 >= 1)
            {
                temp[j] = 1;
                result[j] <<= 1;
                result[j] %= 16;
                if(j < NUM - 1)
                    result[j] += temp[j + 1];
            }
            else if(result[j] / 8 == 0)
            {
                temp[j] = 0;
                result[j] <<= 1;
                result[j] %= 16;
            }
        }
        result[NUM - 1] += temp[0];
    }
    return result;
}

//SHA-1的填充方案,我们设定msg由ASCII码组成
vector<vector<int> > SHA1::SHA_1_PAD(string msg)
{
    int len = msg.length();
    int bit_num = len * 8;
    int i,j;
    int num,lest = bit_num % 512;
    if(lest != 0)   //看消息长度是否超过512字节，我们需要将它补成512的倍数
        num = bit_num / 512 + 1;
    else
        num = bit_num / 512;
    //首先我们以8位字节为一组保存到vector里面，512比特为一组，即一组里面有64位元素
    vector<vector<int> > result;
    result.resize(num);
    for(i = 0;i < num;i++)
    {
        result[i].resize(64);
    }
    for(i = 0;i < num;i++)
    {
        for(j = 0;j < 64 && i * 64 + j < len;j++)
        {
            result[i][j] = msg[i * 64 + j];
        }
    }
    //下面开始为未够512比特的消息分组进行补长度操作
    if(lest != 0){
    int x = num - 1,last_len = lest / 8;
    result[x][last_len] = 128;   //先补一个"1"
    for(i = last_len + 1;i < 56;i++)
    {
        result[x][i] = 0;
    }
    int last_l = lest;
    j = 63;
    while(j >= 56)
    {
        result[x][j] = last_l % 128;
        last_l /= 128;
        j--;
    }
    }
    return result;
}

//将SHA-1压成以字为单位(三维数组有点复杂)
vector<vector<vector<int> > > SHA1::compress(vector<vector<int> > result)
{
    vector<vector<int> > rr;
    rr.resize(result.size());
    int i,j;
    for(i = 0;i < rr.size();i++)
    {
        rr[i].resize(128);
    }
    for(i = 0;i < result.size();i++)
    {
        for(j = 0;j < result[i].size();j++)
        {
            rr[i][2 * j] = result[i][j] / 16;
            rr[i][2 * j + 1] = result[i][j] % 16;
        }
    }
    vector<vector<vector<int> > > rrr;
    rrr.resize(result.size());
    for(i = 0;i < rrr.size();i++)
    {
        rrr[i].resize(16);
    }
    for(i = 0;i < rrr.size();i++)
    {
        for(j = 0;j < 16;j++)
        {
            rrr[i][j].resize(8);
        }
    }
    for(i = 0;i < rr.size();i++)
    {
        for(j = 0;j < rr[i].size();j++)
        {
            rrr[i][j / 8][j % 8] = rr[i][j];
        }
    }
    return rrr;
}

//定义ft函数，每个ft函数都有B,C,D三个字作为输入，并产生一个字作为输出
vector<int> SHA1::Ft(int t,vector<int> B,vector<int> C,vector<int> D)
{
    vector<int> result;
    if(t >= 0 && t <= 19)
    {
        vector<int> a1 = word_AND(B,C);
        vector<int> a2 = word_AND(word_COMPLEMENT(B),D);
        result = word_OR(a1,a2);
    }
    else if((t >= 20 && t <= 39) || (t >= 60 && t <= 79))
    {
        vector<int> a1 = word_XOR(B,C);
        result = word_XOR(a1,D);
    }
    else if(t >= 40 && t <= 59)
    {
        vector<int> a1 = word_AND(B,C);
        vector<int> a2 = word_AND(B,D);
        vector<int> a3 = word_AND(C,D);
        vector<int> a4 = word_OR(a1,a2);
        result = word_OR(a4,a3);
    }
    return result;
}

//定义字常数K
vector<int> SHA1::K(int t)
{
    vector<int> result;
    if(t >= 0 && t <= 19)
    {
        result = hex_into_dec("5A827999");
    }
    else if(t >= 20 && t <= 39)
    {
        result = hex_into_dec("6ED9EBA1");
    }
    else if(t >= 40 && t <= 59)
    {
        result = hex_into_dec("8F1BBCDC");
    }
    else if(t >= 60 && t <= 79)
    {
        result = hex_into_dec("CA62C1D6");
    }
    return result;
}

//开始进行SHA-1(安全Hash算法)的加密
vector<vector<int> > SHA1::SHA_1(string msg)
{
    vector<int> h0 = hex_into_dec(H0);
    vector<int> h1 = hex_into_dec(H1);
    vector<int> h2 = hex_into_dec(H2);
    vector<int> h3 = hex_into_dec(H3);
    vector<int> h4 = hex_into_dec(H4);
    
    vector<vector<int> > result1 = SHA_1_PAD(msg);
    vector<vector<vector<int> > > result2 = compress(result1);
    int n = result2.size();
    int i,j;
    for(i = 0;i < n;i++)
    {
        vector<vector<int> > W;
        W.resize(80);
        for(j = 0;j < 16;j++)
        {
            W[j] = result2[i][j];
        }
        for(j = 16;j < 80;j++)
        {
            vector<int> a1 = word_XOR(W[j-3],W[j-8]);
            vector<int> a2 = word_XOR(a1,W[j-14]);
            vector<int> a3 = word_XOR(a2,W[j-16]);
            W[j] = ROTL(a3,1);
        }
        
        //将string转化为vector数组
        vector<int> A = hex_into_dec(H0);
        vector<int> B = hex_into_dec(H1);
        vector<int> C = hex_into_dec(H2);
        vector<int> D = hex_into_dec(H3);
        vector<int> E = hex_into_dec(H4);

        for(j = 0;j < 80;j++)
        {
            vector<int> a1 = ROTL(A,5);
            vector<int> a2 = Ft(j,B,C,D);
            vector<int> a3 = word_ADD(a1,a2);
            vector<int> a4 = word_ADD(a3,E);
            vector<int> a5 = word_ADD(a4,W[j]);
            vector<int> temp = word_ADD(a5,K(j));
            E = D;
            D = C;
            C = ROTL(B,30);
            B = A;
            A = temp;
        }

        h0 = word_ADD(h0,A);
        h1 = word_ADD(h1,B);
        h2 = word_ADD(h2,C);
        h3 = word_ADD(h3,D);
        h4 = word_ADD(h4,E);
    }

    //返回结果(H0||H1||H2||H3||H4)
    vector<vector<int> > result;
    result.push_back(h0);
    result.push_back(h1);
    result.push_back(h2);
    result.push_back(h3);
    result.push_back(h4);

    return result;
}

int main()
{
    SHA1 sha1;   //定义SHA1算法类
    string message = "cryptographyisthepracticeandstudyoftechniquesforsecurecommunicationinthepresenceofthirdpartiesmoregenerallyitisaboutconstructingandanalyzingprotocolsthatovercometheinfluenceofadversariesandwhicharerelatedtovariousaspectsininformationsecuritysuchasdataconfidentialitydataintegrityauthenticationandnonrepudiationmoderncryptographyintersectsthedisciplinesofmathematicscomputerscienceandelectricalengineeringapplicationsofcryptographyincludeATMcardscomputerpasswordsandelectroniccommerce";
    vector<vector<int> > result;
    result = sha1.SHA_1(message);
    cout << "消息为:" << endl << message << endl;
    cout << "利用填充方案SHA-1-PAD给出对消息的填充,得出SHA-1(x)得:" << endl;
    int i;
    for(i = 0;i < result.size();i++)
    {
        cout << sha1.num_into_message(result[i]);
    }
    cout << endl;
    return 0;
}

就这样，请多多指教！