minix/commands/pwdauth/pwdauth.c
Ben Gras 5c00743626 Switch to NetBSD passwd format
Based on work by Vivek Prakash and Gianluca Guida.

See UPDATING about caveats on currently existing accounts.

	. restores netbsd libc pwcache functions
2011-11-14 14:47:42 +00:00

75 lines
1.9 KiB
C

/* pwdauth 2.0 - check a shadow password Author: Kees J. Bot
* 7 Feb 1994
*
* This program gets as input the key and salt arguments of the crypt(3)
* function as two null terminated strings. The crypt result is output as
* one null terminated string. Input and output must be <= 1024 characters.
* The exit code will be 1 on any error.
*
* If the key has the form '##name' then the key will be encrypted and the
* result checked to be equal to the encrypted password in the shadow password
* file. If equal than '##name' will be returned, otherwise exit code 2.
*
* Otherwise the key will be encrypted normally and the result returned.
*
* As a special case, anything matches a null encrypted password to allow
* a no-password login.
*/
#define nil 0
#include <sys/types.h>
#include <pwd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#ifdef __NBSD_LIBC
#define setkey pwdauth_setkey
#define encrypt pwdauth_encrypt
#endif
#define LEN 1024
int main(int argc, char **argv)
{
char key[LEN];
char *salt;
struct passwd *pw;
int n;
/* Read input data. Check if there are exactly two null terminated
* strings.
*/
n= read(0, key, LEN);
if (n < 0) return 1;
salt = key + n;
n = 0;
while (salt > key) if (*--salt == 0) n++;
if (n != 2) return 1;
salt = key + strlen(key) + 1;
if (salt[0] == '#' && salt[1] == '#') {
if ((pw= getpwnam(salt + 2)) == nil) return 2;
/* A null encrypted password matches a null key, otherwise
* do the normal crypt(3) authentication check.
*/
if (*pw->pw_passwd == 0 && *key == 0) {
/* fine */
} else
if (strcmp(crypt(key, pw->pw_passwd), pw->pw_passwd) != 0) {
return 2;
}
} else {
/* Normal encryption. */
if (*salt == 0 && *key == 0) {
/* fine */
} else {
salt= crypt(key, salt);
}
}
/* Return the (possibly new) salt to the caller. */
if (write(1, salt, strlen(salt) + 1) < 0) return 1;
return 0;
}