aaa.zip.zip_cryptoAPI_www.aaa.chm_zip

#include <stdio.h> #include <windows.h> #include <wincrypt.h> #define MY_ENCODING_TYPE (PKCS_7_ASN_ENCODING | X509_ASN_ENCODING) #define KEYLENGTH 0x00800000 void HandleError(char *s); //-------------------------------------------------------------------- // These additional #define statements are required. #define ENCRYPT_ALGORITHM CALG_RC4 #define ENCRYPT_BLOCK_SIZE 8 // Declare the function EncryptFile. The function definition // follows main. BOOL EncryptFile( PCHAR szSource, PCHAR szDestination, PCHAR szPassword); //-------------------------------------------------------------------- // Begin main. void main(void) { CHAR szSource[100]; CHAR szDestination[100]; CHAR szPassword[100]; printf("Encrypt a file. \n\n"); printf("Enter the name of the file to be encrypted: "); scanf("%s",szSource); printf("Enter the name of the output file: "); scanf("%s",szDestination); printf("Enter the password:"); scanf("%s",szPassword); //-------------------------------------------------------------------- // Call EncryptFile to do the actual encryption. if(EncryptFile(szSource, szDestination, szPassword)) { printf("Encryption of the file %s was a success. \n", szSource); printf("The encrypted data is in file %s.\n",szDestination); } else { HandleError("Error encrypting file!"); } } // End of main //-------------------------------------------------------------------- // Code for the function EncryptFile called by main. static BOOL EncryptFile( PCHAR szSource, PCHAR szDestination, PCHAR szPassword) //-------------------------------------------------------------------- // Parameters passed are: // szSource, the name of the input, a plaintext file. // szDestination, the name of the output, an encrypted file to be // created. // szPassword, the password. { //-------------------------------------------------------------------- // Declare and initialize local variables. FILE *hSource; FILE *hDestination; HCRYPTPROV hCryptProv; HCRYPTKEY hKey; HCRYPTHASH hHash; PBYTE pbBuffer; DWORD dwBlockLen; DWORD dwBufferLen; DWORD dwCount; //-------------------------------------------------------------------- // Open source file. if(hSource = fopen(szSource,"rb")) { printf("The source plaintext file, %s, is open. \n", szSource); } else { HandleError("Error opening source plaintext file!"); } //-------------------------------------------------------------------- // Open destination file. if(hDestination = fopen(szDestination,"wb")) { printf("Destination file %s is open. \n", szDestination); } else { HandleError("Error opening destination ciphertext file!"); } //以下获得一个CSP句柄 if(CryptAcquireContext( &hCryptProv, NULL, //NULL表示使用默认密钥容器，默认密钥容器名为用户登陆名 NULL, PROV_RSA_FULL, 0)) { printf("A cryptographic provider has been acquired. \n"); } else//密钥容器不存在 { if(CryptAcquireContext( &hCryptProv, NULL, NULL, PROV_RSA_FULL, CRYPT_NEWKEYSET))//创建密钥容器 { //创建密钥容器成功，并得到CSP句柄 printf("A new key container has been created.\n"); } else { HandleError("Could not create a new key container.\n"); } } //-------------------------------------------------------------------- // 创建一个会话密钥（session key） // 会话密钥也叫对称密钥，用于对称加密算法。 // （注: 一个Session是指从调用函数CryptAcquireContext到调用函数 // CryptReleaseContext 期间的阶段。） //-------------------------------------------------------------------- // Create a hash object. if(CryptCreateHash( hCryptProv, CALG_MD5, 0, 0, &hHash)) { printf("A hash object has been created. \n"); } else { HandleError("Error during CryptCreateHash!\n"); } //-------------------------------------------------------------------- // 用输入的密码产生一个散列 if(CryptHashData( hHash, (BYTE *)szPassword, strlen(szPassword), 0)) { printf("The password has been added to the hash. \n"); } else { HandleError("Error during CryptHashData. \n"); } //-------------------------------------------------------------------- // 通过散列生成会话密钥(session key) if(CryptDeriveKey( hCryptProv, ENCRYPT_ALGORITHM, hHash, KEYLENGTH, &hKey)) { printf("An encryption key is derived from the password hash. \n"); } else { HandleError("Error during CryptDeriveKey!\n"); } //-------------------------------------------------------------------- // Destroy the hash object. CryptDestroyHash(hHash); hHash = NULL; //-------------------------------------------------------------------- // The session key is now ready. //-------------------------------------------------------------------- // 因为加密算法是按ENCRYPT_BLOCK_SIZE 大小的块加密的，所以被加密的 // 数据长度必须是ENCRYPT_BLOCK_SIZE 的整数倍。下面计算一次加密的 // 数据长度。 dwBlockLen = 1000 - 1000 % ENCRYPT_BLOCK_SIZE; //-------------------------------------------------------------------- // Determine the block size. If a block cipher is used, // it must have room for an extra block. if(ENCRYPT_BLOCK_SIZE > 1) dwBufferLen = dwBlockLen + ENCRYPT_BLOCK_SIZE; else dwBufferLen = dwBlockLen; //-------------------------------------------------------------------- // Allocate memory. if(pbBuffer = (BYTE *)malloc(dwBufferLen)) { printf("Memory has been allocated for the buffer. \n"); } else { HandleError("Out of memory. \n"); } //-------------------------------------------------------------------- // In a do loop, encrypt the source file and write to the source file. do { //-------------------------------------------------------------------- // Read up to dwBlockLen bytes from the source file. dwCount = fread(pbBuffer, 1, dwBlockLen, hSource); if(ferror(hSource)) { HandleError("Error reading plaintext!\n"); } //-------------------------------------------------------------------- // 加密数据 if(!CryptEncrypt( hKey, //密钥 0, //如果数据同时进行散列和加密，这里传入一个散列对象 feof(hSource), //如果是最后一个被加密的块，输入TRUE.如果不是输入FALSE. //这里通过判断是否到文件尾来决定是否为最后一块。 0, //保留 pbBuffer, //输入被加密数据，输出加密后的数据 &dwCount, //输入被加密数据实际长度，输出加密后数据长度 dwBufferLen)) //pbBuffer的大小。 { HandleError("Error during CryptEncrypt. \n"); } //-------------------------------------------------------------------- // Write data to the destination file. fwrite(pbBuffer, 1, dwCount, hDestination); if(ferror(hDestination)) { HandleError("Error writing ciphertext."); } } while(!feof(hSource)); //-------------------------------------------------------------------- // End the do loop when the last block of the source file has been // read, encrypted, and written to the destination file. //-------------------------------------------------------------------- // Close files. if(hSource) fclose(hSource); if(hDestination) fclose(hDestination); //-------------------------------------------------------------------- // Free memory. if(pbBuffer) free(pbBuffer); //-------------------------------------------------------------------- // Destroy session key. if(hKey) CryptDestroyKey(hKey); //-------------------------------------------------------------------- // Destroy hash object. if(hHash) CryptDestroyHash(hHash); //---------------------------------------------