diff options
Diffstat (limited to 'src/auth')
| -rw-r--r-- | src/auth/crypt.c | 122 | ||||
| -rw-r--r-- | src/auth/crypt.h | 41 |
2 files changed, 163 insertions, 0 deletions
diff --git a/src/auth/crypt.c b/src/auth/crypt.c new file mode 100644 index 0000000..27238e2 --- /dev/null +++ b/src/auth/crypt.c @@ -0,0 +1,122 @@ +/** + * cerberus – Minimal login program + * + * Copyright © 2013 Mattias Andrée (maandree@member.fsf.org) + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ +#ifndef NO_SHADOW +# ifndef HAVE_SHADOW +# define HAVE_SHADOW +# endif +#endif + +#define _XOPEN_SOURCE +#include <unistd.h> +#include <stdio.h> +#include <sys/types.h> +#include <pwd.h> +#include <string.h> +#ifdef HAVE_SHADOW +#include <shadow.h> +#endif + +#include "../config.h" + +#include "crypt.h" + + +#if !defined(__USE_SVID) && !defined(__USE_MISC) && !defined(__USE_XOPEN_EXTENDED) +#define endpwent() /* do nothing */ +#endif + + +/** + * Function that can be used to read a passphrase from the terminal + */ +static char* (*passphrase_reader)(void) = NULL; + +/** + * The username of the user to log in to + */ +static char* login_username; + + + +/** + * Initialise crypt authentication module + * + * @param remote The remote computer, {@code NULL} for local login + * @param username The username of the user to log in to + * @param reader Function that can be used to read a passphrase from the terminal + */ +void initialise_crypt(char* remote, char* username, char* (*reader)(void)) +{ + (void) remote; + + login_username = username; + passphrase_reader = reader; +} + + +/** + * Perform token authentication + * + * @return Whether the user got automatically authenticated + */ +char authenticate_crypt(void) +{ +#ifdef HAVE_SHADOW + struct spwd* shadow_entry = NULL; +#endif + struct passwd* passwd_entry = NULL; + char* crypted; + char* entered; + +#ifdef HAVE_SHADOW + shadow_entry = getspnam(login_username); + endspent(); + + if (shadow_entry) + crypted = shadow_entry->sp_pwdp; + else + { +#endif + passwd_entry = getpwnam(login_username); + if (passwd_entry) + crypted = passwd_entry->pw_passwd; + else + { + perror("getpwnam"); + endpwent(); + sleep(ERROR_SLEEP); + _exit(1); + } + endpwent(); +#ifdef HAVE_SHADOW + } +#endif + + if (!(crypted && *crypted)) /* empty means that no passphrase is required (not even Enter) */ + return 1; + + entered = crypt(passphrase_reader(), crypted /* salt argument stops parsing when encrypted begins */); + if (entered && !strcmp(entered, crypted)) + return 0; + + printf("Incorrect passphrase\n"); + sleep(FAILURE_SLEEP); + _exit(1); +} + diff --git a/src/auth/crypt.h b/src/auth/crypt.h new file mode 100644 index 0000000..e75c5b5 --- /dev/null +++ b/src/auth/crypt.h @@ -0,0 +1,41 @@ +/** + * cerberus – Minimal login program + * + * Copyright © 2013 Mattias Andrée (maandree@member.fsf.org) + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ +#ifndef __CRYPT_H__ +#define __CRYPT_H__ + + +/** + * Initialise crypt authentication module + * + * @param remote The remote computer, {@code NULL} for local login + * @param username The username of the user to log in to + * @param reader Function that can be used to read a passphrase from the terminal + */ +void initialise_crypt(char* remote, char* username, char* (*reader)(void)); + +/** + * Perform token authentication + * + * @return Whether the user got automatically authenticated + */ +char authenticate_crypt(void); + + +#endif + |