网上没找到什么资料，最后还是看login源码找到的方法。
/*
* 密码加密
*
* 编译： cc pwd.c -lcrypt
* usage:
* ./a.out passwd
*
*
*/
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| #include
#include
#include
#include
#include
#define SHADOW_PWD
int checkpasswd(const char *username, const char *passwd)
{
struct passwd *pwd=NULL;
char *salt=NULL;
if ((pwd = getpwnam(username))) {
# ifdef SHADOW_PWD
struct spwd *sp;
if ((sp = getspnam(username)))
pwd->pw_passwd = sp->sp_pwdp;
# endif
salt = pwd->pw_passwd;
} else
salt = "xx";
//printf("read from /etc/shadow passwd:\t%s\n",pwd->pw_passwd);
//printf("crypted from %s passwd:\t%s\n",passwd,crypt(passwd, salt));
if (!strncmp(crypt(passwd, salt),pwd->pw_passwd,strlen(pwd->pw_passwd))) {
return 0;
}
return -1;
}
int main(int argc, char **argv)
{
int ret=checkpasswd(argv[1],argv[2]);
if (!ret)
printf("success\n");
else
printf("wrong passwd\n");
return 0;
} |