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

 //字常量
 string H0 = "";
 string H1 = "EFCDAB89";
 string H2 = "98BADCFE";
 string H3 = "";
 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 = ;i < A.size();i++)
     {
         if(A[i] >=  && A[i] <= )
             msg += '' + A[i];
         else if(A[i] >=  && A[i] <= )
             msg += 'A' + (A[i] - );
     }
     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,);
     for(i = ;i < NUM;i++)
     {
         if(word[i] >= '' && word[i] <= '')
         {
             result[i] = word[i] - '';
         }
         else if(word[i] >= 'A' && word[i] <= 'F')
         {
             result[i] =  + 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,);
     int i;
     for(i = ;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,);
     int i;
     for(i = ;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,);
     int i;
     for(i = ;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,);
     int i;
     for(i = ;i < NUM;i++)
     {
         result[i] =  - 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,);
     int i;
     for(i = NUM - ;i >= ;i--)
     {
         result[i] = A[i] + B[i];
         if(i != )
         {
             int temp = result[i] / ;
             result[i-] += temp;
         }
         result[i] %= ;
     }
     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,);
     int i,j;
     for(i = ;i < s;i++)
     {
         for(j = NUM - ;j >= ;j--)
         {
             if(result[j] /  >= )
             {
                 temp[j] = ;
                 result[j] <<= ;
                 result[j] %= ;
                 if(j < NUM - )
                     result[j] += temp[j + ];
             }
             else if(result[j] /  == )
             {
                 temp[j] = ;
                 result[j] <<= ;
                 result[j] %= ;
             }
         }
         result[NUM - ] += temp[];
     }
     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 * ;
     int i,j;
     int num,lest = bit_num % ;
     if(lest != )   //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 /  + ;
     else
         num = bit_num / ;
     //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 = ;i < num;i++)
     {
         result[i].resize();
     }
     for(i = ;i < num;i++)
     {
         for(j = ;j <  && i *  + j < len;j++)
         {
             result[i][j] = msg[i *  + 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 != ){
     int x = num - ,last_len = lest / ;
     result[x][last_len] = ;   //先补一个"1"
     for(i = last_len + ;i < ;i++)
     {
         result[x][i] = ;
     }
     int last_l = lest;
     j = ;
     while(j >= )
     {
         result[x][j] = last_l % ;
         last_l /= ;
         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 = ;i < rr.size();i++)
     {
         rr[i].resize();
     }
     for(i = ;i < result.size();i++)
     {
         for(j = ;j < result[i].size();j++)
         {
             rr[i][ * j] = result[i][j] / ;
             rr[i][ * j + ] = result[i][j] % ;
         }
     }
     vector<vector<vector<int> > > rrr;
     rrr.resize(result.size());
     for(i = ;i < rrr.size();i++)
     {
         rrr[i].resize();
     }
     for(i = ;i < rrr.size();i++)
     {
         for(j = ;j < ;j++)
         {
             rrr[i][j].resize();
         }
     }
     for(i = ;i < rr.size();i++)
     {
         for(j = ;j < rr[i].size();j++)
         {
             rrr[i][j / ][j % ] = 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 >=  && t <= )
     {
         vector<int> a1 = word_AND(B,C);
         vector<int> a2 = word_AND(word_COMPLEMENT(B),D);
         result = word_OR(a1,a2);
     }
     else if((t >=  && t <= ) || (t >=  && t <= ))
     {
         vector<int> a1 = word_XOR(B,C);
         result = word_XOR(a1,D);
     }
     else if(t >=  && t <= )
     {
         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 >=  && t <= )
     {
         result = hex_into_dec("5A827999");
     }
     else if(t >=  && t <= )
     {
         result = hex_into_dec("6ED9EBA1");
     }
     else if(t >=  && t <= )
     {
         result = hex_into_dec("8F1BBCDC");
     }
     else if(t >=  && t <= )
     {
         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 = ;i < n;i++)
     {
         vector<vector<int> > W;
         W.resize();
         for(j = ;j < ;j++)
         {
             W[j] = result2[i][j];
         }
         for(j = ;j < ;j++)
         {
             vector<int> a1 = word_XOR(W[j-],W[j-]);
             vector<int> a2 = word_XOR(a1,W[j-]);
             vector<int> a3 = word_XOR(a2,W[j-]);
             W[j] = ROTL(a3,);
         }

         //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 = ;j < ;j++)
         {
             vector<int> a1 = ROTL(A,);
             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,);
             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 = ;i < result.size();i++)
     {
         cout << sha1.num_into_message(result[i]);
     }
     cout << endl;
     return ;
 }

就这样，请多多指教！