C++/python求哈希值(SHA256)

发现一个很奇怪的现象：

python语言求哈希值所用时间竟然比C++少：

C++ code

  1 #include "stdafx.h"
  2 #include <windows.h>
  3 #include <time.h>
  4 #include <iostream>
  5 void ShowError(char *pszText)
  6 {
  7     char szErr[MAX_PATH] = { 0 };
  8     ::sprintf_s(szErr, "%s Error[%d]\n", pszText, ::GetLastError());
  9 #ifdef _DEBUG
 10     // required size
 11     int size = MultiByteToWideChar(CP_UTF8, 0, szErr, -1, NULL, 0);
 12     wchar_t *pwcsName = new wchar_t[size];
 13     MultiByteToWideChar(CP_UTF8, 0, szErr, -1, (LPWSTR)pwcsName, size);
 14     ::MessageBox(NULL, pwcsName, L"ERROR", MB_OK | MB_ICONERROR);
 15     delete[] pwcsName;
 16 #endif
 17 }
 18
 19
 20 BOOL GetFileData(char *pszFilePath, BYTE **ppFileData, DWORD *pdwFileDataLength)
 21 {
 22     BOOL bRet = TRUE;
 23     BYTE *pFileData = NULL;
 24     DWORD dwFileDataLength = 0;
 25     HANDLE hFile = NULL;
 26     DWORD dwTemp = 0;
 27
 28     do
 29     {
 30         // required size
 31         int size = MultiByteToWideChar(CP_UTF8, 0, pszFilePath, -1, NULL, 0);
 32         wchar_t *pwcsName = new wchar_t[size];
 33         MultiByteToWideChar(CP_UTF8, 0, pszFilePath, -1, (LPWSTR)pwcsName, size);
 34         hFile = ::CreateFile(pwcsName, GENERIC_READ | GENERIC_WRITE,
 35             FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING,
 36             FILE_ATTRIBUTE_ARCHIVE, NULL);
 37         delete[] pwcsName;
 38         if (INVALID_HANDLE_VALUE == hFile)
 39         {
 40             bRet = FALSE;
 41             ShowError("CreateFile");
 42             break;
 43         }
 44
 45         dwFileDataLength = ::GetFileSize(hFile, NULL);
 46
 47         pFileData = new BYTE[dwFileDataLength];
 48         if (NULL == pFileData)
 49         {
 50             bRet = FALSE;
 51             ShowError("new");
 52             break;
 53         }
 54         ::RtlZeroMemory(pFileData, dwFileDataLength);
 55
 56         ::ReadFile(hFile, pFileData, dwFileDataLength, &dwTemp, NULL);
 57
 58         // 返回
 59         *ppFileData = pFileData;
 60         *pdwFileDataLength = dwFileDataLength;
 61
 62     } while (FALSE);
 63
 64     if (hFile)
 65     {
 66         ::CloseHandle(hFile);
 67     }
 68
 69     return bRet;
 70 }
 71
 72
 73 BOOL CalculateHash(BYTE *pData, DWORD dwDataLength, ALG_ID algHashType, BYTE **ppHashData, DWORD *pdwHashDataLength)
 74 {
 75     HCRYPTPROV hCryptProv = NULL;
 76     HCRYPTHASH hCryptHash = NULL;
 77     BYTE *pHashData = NULL;
 78     DWORD dwHashDataLength = 0;
 79     DWORD dwTemp = 0;
 80     BOOL bRet = FALSE;
 81
 82
 83     do
 84     {
 85         // 获得指定CSP的密钥容器的句柄
 86         bRet = ::CryptAcquireContext(&hCryptProv, NULL, NULL, PROV_RSA_AES, CRYPT_VERIFYCONTEXT);
 87         if (FALSE == bRet)
 88         {
 89             ShowError("CryptAcquireContext");
 90             break;
 91         }
 92
 93         // 创建一个HASH对象, 指定HASH算法
 94         bRet = ::CryptCreateHash(hCryptProv, algHashType, NULL, NULL, &hCryptHash);
 95         if (FALSE == bRet)
 96         {
 97             ShowError("CryptCreateHash");
 98             break;
 99         }
100
101         // 计算HASH数据
102         bRet = ::CryptHashData(hCryptHash, pData, dwDataLength, 0);
103         if (FALSE == bRet)
104         {
105             ShowError("CryptHashData");
106             break;
107         }
108
109         // 获取HASH结果的大小
110         dwTemp = sizeof(dwHashDataLength);
111         bRet = ::CryptGetHashParam(hCryptHash, HP_HASHSIZE, (BYTE *)(&dwHashDataLength), &dwTemp, 0);
112         if (FALSE == bRet)
113         {
114             ShowError("CryptGetHashParam");
115             break;
116         }
117
118         // 申请内存
119         pHashData = new BYTE[dwHashDataLength];
120         if (NULL == pHashData)
121         {
122             bRet = FALSE;
123             ShowError("new");
124             break;
125         }
126         ::RtlZeroMemory(pHashData, dwHashDataLength);
127
128         // 获取HASH结果数据
129         bRet = ::CryptGetHashParam(hCryptHash, HP_HASHVAL, pHashData, &dwHashDataLength, 0);
130         if (FALSE == bRet)
131         {
132             ShowError("CryptGetHashParam");
133             break;
134         }
135
136         // 返回数据
137         *ppHashData = pHashData;
138         *pdwHashDataLength = dwHashDataLength;
139
140     } while (FALSE);
141
142     // 释放关闭
143     if (FALSE == bRet)
144     {
145         if (pHashData)
146         {
147             delete[]pHashData;
148             pHashData = NULL;
149         }
150     }
151     if (hCryptHash)
152     {
153         ::CryptDestroyHash(hCryptHash);
154     }
155     if (hCryptProv)
156     {
157         ::CryptReleaseContext(hCryptProv, 0);
158     }
159
160     return bRet;
161 }
162
163
164 int _tmain(int argc, _TCHAR* argv[])
165 {
166     BYTE *pData = NULL;
167     DWORD dwDataLength = 0;
168     DWORD i = 0;
169     BYTE *pHashData = NULL;
170     DWORD dwHashDataLength = 0;
171
172     // 读取文件数据
173     GetFileData("C:\\Users\\Administrator\\Desktop\\paraseLED\\white\\process.exe", &pData, &dwDataLength);
174
175     // MD5
176     CalculateHash(pData, dwDataLength, CALG_MD5, &pHashData, &dwHashDataLength);
177     printf("MD5[%d]\n", dwHashDataLength);
178     for (i = 0; i < dwHashDataLength; i++)
179     {
180         printf("%x", pHashData[i]);
181     }
182     printf("\n\n");
183     if (pHashData)
184     {
185         delete[]pHashData;
186         pHashData = NULL;
187     }
188
189     // SHA1
190     CalculateHash(pData, dwDataLength, CALG_SHA1, &pHashData, &dwHashDataLength);
191     printf("SHA1[%d]\n", dwHashDataLength);
192     std::string hash_ = "";
193     for (i = 0; i < dwHashDataLength; i++)
194     {
195         char temp[32] = { 0 };
196         sprintf_s(temp, "%x", pHashData[i]);
197         hash_.append(temp);
198         printf("%x", pHashData[i]);
199     }
200     printf("\n\n");
201     std::cout << hash_.c_str() << std::endl;
202     printf("\n\n");
203     if (pHashData)
204     {
205         delete[]pHashData;
206         pHashData = NULL;
207     }
208
209     // SHA256
210     clock_t start, end;
211     start = clock();
212     CalculateHash(pData, dwDataLength, CALG_SHA_256, &pHashData, &dwHashDataLength);
213     printf("SHA256[%d]\n", dwHashDataLength);
214     for (i = 0; i < dwHashDataLength; i++)
215     {
216         printf("%x", pHashData[i]);
217     }
218     end = clock();
219     printf("\n\n");
220     printf("timestamp = %f\n", double(end - start) / CLOCKS_PER_SEC);
221     if (pHashData)
222     {
223         delete[]pHashData;
224         pHashData = NULL;
225     }
226
227     system("pause");
228     return 0;
229 }

python code

 1 # Python program to find SHA256 hexadecimal hash string of a file
 2 import hashlib
 3 import time
 4
 5 start = time.time()
 6 filename = r'C:\Users\Administrator\Desktop\paraseLED\white\process.exe'
 7 with open(filename,"rb") as f:
 8     bytes = f.read() # read entire file as bytes
 9     readable_hash = hashlib.sha256(bytes).hexdigest();
10     print(readable_hash)
11 end = time.time()
12 print('timestamp = {}'.format(end - start))