toaruos/lib/auth.c

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/**
* @brief Authentication routines.
*
* @copyright
* This file is part of ToaruOS and is released under the terms
* of the NCSA / University of Illinois License - see LICENSE.md
* Copyright (C) 2013-2018 K. Lange
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <pwd.h>
#ifndef fgetpwent
extern struct passwd *fgetpwent(FILE *stream);
#endif
extern int setgroups(int size, const gid_t list[]);
#define MASTER_PASSWD "/etc/master.passwd"
int toaru_auth_check_pass(char * user, char * pass) {
/* XXX DO something useful */
/* Open up /etc/master.passwd */
FILE * master = fopen(MASTER_PASSWD, "r");
struct passwd * p;
while ((p = fgetpwent(master))) {
if (!strcmp(p->pw_name, user) && !strcmp(p->pw_passwd, pass)) {
fclose(master);
return p->pw_uid;
}
}
fclose(master);
return -1;
}
void toaru_auth_set_vars(void) {
int uid = getuid();
struct passwd * p = getpwuid(uid);
if (!p) {
char tmp[10];
sprintf(tmp, "%d", uid);
setenv("USER", strdup(tmp), 1);
setenv("HOME", "/", 1);
setenv("SHELL", "/bin/sh", 1);
} else {
setenv("USER", strdup(p->pw_name), 1);
setenv("HOME", strdup(p->pw_dir), 1);
setenv("SHELL", strdup(p->pw_shell), 1);
setenv("WM_THEME", strdup(p->pw_comment), 1);
}
endpwent();
setenv("PATH", "/usr/bin:/bin", 0);
chdir(getenv("HOME"));
}
void toaru_auth_set_groups(uid_t uid) {
/* Get the username for this uid */
struct passwd * pwd = getpwuid(uid);
/* No username? No group memberships! */
if (!pwd) goto no_groups;
/* Open the group file */
FILE * groupList = fopen("/etc/group","r");
/* No groups? No membership. */
if (!groupList) goto no_groups;
/* Scan through lines of groups. */
#define LINE_LEN 2048
char * pw_blob = malloc(LINE_LEN);
int groupCount = 0;
gid_t myGroups[32] = {0};
while (!feof(groupList)) {
memset(pw_blob, 0x00, LINE_LEN);
fgets(pw_blob, LINE_LEN, groupList);
if (pw_blob[strlen(pw_blob)-1] == '\n') {
pw_blob[strlen(pw_blob)-1] = '\0'; /* erase newline */
}
/* Tokenize */
char * memberlist = NULL;
char *p, *last;
gid_t groupNumber = -1;
int i = 0;
for ((p = strtok_r(pw_blob, ":", &last)); p;
(p = strtok_r(NULL, ":", &last)), i++) {
if (i == 2) {
groupNumber = atoi(p);
} else if (i == 3) {
memberlist = p;
break;
}
}
if (groupNumber == -1) continue;
if (!memberlist) continue;
for ((p = strtok_r(memberlist, ",", &last)); p;
(p = strtok_r(NULL, ",", &last))) {
if (!strcmp(p, pwd->pw_name)) {
if (groupCount < 32) {
myGroups[groupCount] = groupNumber;
groupCount++;
}
}
}
}
setgroups(groupCount, myGroups);
free(pw_blob);
fclose(groupList);
return;
no_groups:
setgroups(0, NULL);
}
void toaru_set_credentials(uid_t uid) {
toaru_auth_set_groups(uid);
setgid(uid);
setuid(uid);
toaru_auth_set_vars();
}