toaruos/userspace/core/sudo.c
2014-06-07 23:13:29 -07:00

125 lines
2.5 KiB
C

/* This file is part of ToaruOS and is released under the terms
* of the NCSA / University of Illinois License - see LICENSE.md
* Copyright (C) 2014 Kevin Lange
*/
/* vim: tabstop=4 shiftwidth=4 noexpandtab
*
* sudo
*
*/
#include <stdio.h>
#include <stdint.h>
#include <syscall.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <time.h>
#include <signal.h>
#include <termios.h>
#include <errno.h>
#include <sys/wait.h>
#include <sys/utsname.h>
#include "lib/sha2.h"
#define LINE_LEN 1024
uint32_t child = 0;
int checkUserPass(char * user, char * pass) {
/* Generate SHA512 */
char hash[SHA512_DIGEST_STRING_LENGTH];
SHA512_Data(pass, strlen(pass), hash);
/* Open up /etc/master.passwd */
FILE * passwd = fopen("/etc/master.passwd", "r");
char line[2048];
while (fgets(line, 2048, passwd) != NULL) {
line[strlen(line)-1] = '\0';
char *p, *tokens[4], *last;
int i = 0;
for ((p = strtok_r(line, ":", &last)); p;
(p = strtok_r(NULL, ":", &last)), i++) {
if (i < 511) tokens[i] = p;
}
tokens[i] = NULL;
if (strcmp(tokens[0],user) != 0) {
continue;
}
if (!strcmp(tokens[1],hash)) {
fclose(passwd);
return atoi(tokens[2]);
}
}
fclose(passwd);
return -1;
}
void usage(int argc, char * argv[]) {
fprintf(stderr, "usage: %s [command]\n", argv[0]);
}
int main(int argc, char ** argv) {
int fails = 0;
if (argc < 2) {
usage(argc, argv);
return 1;
}
while (1) {
/*
* This is not very secure, but I'm lazy and just want this to exist.
* It's not like we have file system permissions or anything like
* that sitting around anyway... So, XXX: make this not dumb.
*/
char * username = getenv("USER");
char * password = malloc(sizeof(char) * 1024);
fprintf(stdout, "[%s] password for %s: ", argv[0], username);
fflush(stdout);
/* Disable echo */
struct termios old, new;
tcgetattr(fileno(stdin), &old);
new = old;
new.c_lflag &= (~ECHO);
tcsetattr(fileno(stdin), TCSAFLUSH, &new);
fgets(password, 1024, stdin);
password[strlen(password)-1] = '\0';
tcsetattr(fileno(stdin), TCSAFLUSH, &old);
fprintf(stdout, "\n");
int uid = checkUserPass(username, password);
if (uid < 0) {
fails++;
if (fails == 3) {
fprintf(stderr, "%s: %d incorrect password attempts\n", argv[0]);
break;
}
fprintf(stderr, "Sorry, try again.\n");
continue;
}
char ** args = &argv[1];
int i = execvp(args[0], args);
/* XXX: There are other things that can cause an exec to fail. */
fprintf(stderr, "%s: %s: command not found\n", argv[0], args[0]);
}
return 1;
}