张家港那家做网站,深圳seo推广公司,辽宁省建设工程信息网入辽打印,网站登录怎么做SHA256 例程
一般文件的完整性要使用md5或者sha进行完整性校验#xff0c;这里提供两个函数#xff0c;
intact_update_sha 是计算指定文件SHA值并保存到SHA文件
intact_check_sha 计算文件SHA值并和SHA文件进行对比
编译方法#xff1a;
gcc demo.c -lssl -lcrypto
#…SHA256 例程
一般文件的完整性要使用md5或者sha进行完整性校验这里提供两个函数
intact_update_sha 是计算指定文件SHA值并保存到SHA文件
intact_check_sha 计算文件SHA值并和SHA文件进行对比
编译方法
gcc demo.c -lssl -lcrypto
#include stdio.h
#include openssl/sha.h
#include string.h
#include unistd.h
#include sys/stat.h
#include sys/types.h
#include openssl/md5.h
#include stdlib.henum {ERR_OK,ERR_FAIL,ERR_OPEN,ERR_OPEN_SHA,ERR_PATH,ERR_PARAM,ERR_NOEXIST,ERR_NOEXIST_SHA,ERR_KEY,ERR_MALLOC,};#define MAX_BUFFER_SIZE 1024
#define SHA_FILE_PATH /home/hfs/sha/%s.sha
#define SHA_FILE_DIR /home/hfs/shastatic int intact_get_sha_file_path(char *path)
{int offset 0;for (int i 0; i strlen(path); i) {if (*(path i) /)offset i;}return offset;
}
int intact_check_sha(char *path)
{SHA256_CTX ctx;char buffer[MAX_BUFFER_SIZE];char sha_str[MAX_BUFFER_SIZE];int len 0;FILE *fp NULL;FILE *fp_sha NULL;unsigned char sha[SHA256_DIGEST_LENGTH];char tmp[MAX_BUFFER_SIZE] {0};char sha_file[MAX_BUFFER_SIZE] {0};int offset;if (path NULL) {return ERR_PARAM;}if (access(path, F_OK)) {return ERR_NOEXIST;}strcpy(tmp, path);if (tmp[strlen(tmp) - 1] /) {tmp[strlen(tmp) - 1] \0;}offset intact_get_sha_file_path(tmp);if (offset 0) {return ERR_PATH;}sprintf(sha_file, SHA_FILE_PATH, tmp offset 1);if (access(sha_file, F_OK)) {return ERR_NOEXIST_SHA;}fp fopen(path, r);if (fp NULL) { return ERR_OPEN; }fp_sha fopen(sha_file, r);if (fp NULL) { fclose(fp);fp NULL;return ERR_OPEN_SHA; } SHA256_Init(ctx);while ((len fread(buffer, 1, MAX_BUFFER_SIZE, fp)) 0) {SHA256_Update(ctx, buffer, len); memset(buffer, 0, sizeof(buffer)); } SHA256_Final((sha[0]), ctx);sprintf(sha_str, %02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x,sha[0], sha[1], sha[2], sha[3], sha[4], sha[5], sha[6], sha[7],sha[8], sha[9], sha[10], sha[11], sha[12], sha[13], sha[14], sha[15]);fread(buffer, 1, MAX_BUFFER_SIZE, fp_sha);if (strncmp(sha_str, buffer, 32) 0) {fclose(fp);fp NULL;fclose(fp_sha);fp_sha NULL;return ERR_OK;}fclose(fp);fp NULL;fclose(fp_sha);fp_sha NULL;return ERR_FAIL;
}
int intact_update_sha(char *path)
{SHA256_CTX ctx;char buffer[MAX_BUFFER_SIZE];char sha_str[MAX_BUFFER_SIZE] {0};int len 0;FILE *fp NULL;FILE *fp_sha NULL;unsigned char sha[SHA256_DIGEST_LENGTH];char tmp[MAX_BUFFER_SIZE] {0};char sha_file[MAX_BUFFER_SIZE] {0};int offset;if (path NULL) {return ERR_PARAM;}if (access(path, F_OK)) {return ERR_NOEXIST;}strcpy(tmp, path);if (tmp[strlen(tmp) - 1] /) {tmp[strlen(tmp) - 1] \0;}offset intact_get_sha_file_path(tmp);if (offset 0) {return ERR_PATH;}sprintf(sha_file, SHA_FILE_PATH, tmp offset 1);if (access(SHA_FILE_DIR, F_OK)) {mkdir(SHA_FILE_DIR, S_IRUSR | S_IWUSR | S_IXUSR);}fp fopen(path, r);if (fp NULL) { return ERR_OPEN; }fp_sha fopen(sha_file, w);if (fp NULL) { fclose(fp);fp NULL;return ERR_OPEN_SHA; } SHA256_Init(ctx);while ((len fread(buffer, 1, MAX_BUFFER_SIZE, fp)) 0) {SHA256_Update(ctx, buffer, len); memset(buffer, 0, sizeof(buffer)); } SHA256_Final((sha[0]), ctx);sprintf(sha_str, %02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x,sha[0], sha[1], sha[2], sha[3], sha[4], sha[5], sha[6], sha[7],sha[8], sha[9], sha[10], sha[11], sha[12], sha[13], sha[14], sha[15]);fwrite(sha_str, 1, MAX_BUFFER_SIZE, fp_sha);fclose(fp);fp NULL;fclose(fp_sha);fp_sha NULL;return ERR_OK;
}
