diff options
Diffstat (limited to 'modules/pam_unix/pam_unix_auth.c')
| -rw-r--r-- | modules/pam_unix/pam_unix_auth.c | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/modules/pam_unix/pam_unix_auth.c b/modules/pam_unix/pam_unix_auth.c new file mode 100644 index 00000000..dfedd608 --- /dev/null +++ b/modules/pam_unix/pam_unix_auth.c @@ -0,0 +1,229 @@ +/* + * Copyright Alexander O. Yuriev, 1996. All rights reserved. + * NIS+ support by Thorsten Kukuk <kukuk@weber.uni-paderborn.de> + * Copyright Jan Rêkorajski, 1999. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, and the entire permission notice in its entirety, + * including the disclaimer of warranties. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote + * products derived from this software without specific prior + * written permission. + * + * ALTERNATIVELY, this product may be distributed under the terms of + * the GNU Public License, in which case the provisions of the GPL are + * required INSTEAD OF the above restrictions. (This clause is + * necessary due to a potential bad interaction between the GPL and + * the restrictions contained in a BSD-style copyright.) + * + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, + * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED + * OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/* #define DEBUG */ + +#include "config.h" + +#include <stdio.h> +#include <stdlib.h> +#include <stdarg.h> +#include <string.h> +#include <unistd.h> +#include <fcntl.h> +#include <ctype.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <syslog.h> + +/* indicate the following groups are defined */ + +#define PAM_SM_AUTH + +#define _PAM_EXTERN_FUNCTIONS +#include <security/_pam_macros.h> +#include <security/pam_modules.h> +#include <security/pam_ext.h> + +#include "support.h" + +/* + * PAM framework looks for these entry-points to pass control to the + * authentication module. + */ + +/* Fun starts here :) + + * pam_sm_authenticate() performs UNIX/shadow authentication + * + * First, if shadow support is available, attempt to perform + * authentication using shadow passwords. If shadow is not + * available, or user does not have a shadow password, fallback + * onto a normal UNIX authentication + */ + +#define _UNIX_AUTHTOK "-UN*X-PASS" + +#define AUTH_RETURN \ +do { \ + if (on(UNIX_LIKE_AUTH, ctrl) && ret_data) { \ + D(("recording return code for next time [%d]", \ + retval)); \ + *ret_data = retval; \ + pam_set_data(pamh, "unix_setcred_return", \ + (void *) ret_data, setcred_free); \ + } else if (ret_data) \ + free (ret_data); \ + D(("done. [%s]", pam_strerror(pamh, retval))); \ + return retval; \ +} while (0) + + +static void +setcred_free (pam_handle_t *pamh UNUSED, void *ptr, int err UNUSED) +{ + if (ptr) + free (ptr); +} + + +PAM_EXTERN int pam_sm_authenticate(pam_handle_t * pamh, int flags + ,int argc, const char **argv) +{ + unsigned int ctrl; + int retval, *ret_data = NULL; + const char *name; + const void *p; + + D(("called.")); + + ctrl = _set_ctrl(pamh, flags, NULL, NULL, argc, argv); + + /* Get a few bytes so we can pass our return value to + pam_sm_setcred(). */ + if (on(UNIX_LIKE_AUTH, ctrl)) + ret_data = malloc(sizeof(int)); + + /* get the user'name' */ + + retval = pam_get_user(pamh, &name, NULL); + if (retval == PAM_SUCCESS) { + /* + * Various libraries at various times have had bugs related to + * '+' or '-' as the first character of a user name. Don't + * allow this characters here. + */ + if (name == NULL || name[0] == '-' || name[0] == '+') { + pam_syslog(pamh, LOG_ERR, "bad username [%s]", name); + retval = PAM_USER_UNKNOWN; + AUTH_RETURN; + } + if (retval == PAM_SUCCESS && on(UNIX_DEBUG, ctrl)) + D(("username [%s] obtained", name)); + } else { + D(("trouble reading username")); + if (retval == PAM_CONV_AGAIN) { + D(("pam_get_user/conv() function is not ready yet")); + /* it is safe to resume this function so we translate this + * retval to the value that indicates we're happy to resume. + */ + retval = PAM_INCOMPLETE; + } + AUTH_RETURN; + } + + /* if this user does not have a password... */ + + if (_unix_blankpasswd(pamh, ctrl, name)) { + D(("user '%s' has blank passwd", name)); + name = NULL; + retval = PAM_SUCCESS; + AUTH_RETURN; + } + /* get this user's authentication token */ + + retval = _unix_read_password(pamh, ctrl, NULL, _("Password: "), NULL + ,_UNIX_AUTHTOK, &p); + if (retval != PAM_SUCCESS) { + if (retval != PAM_CONV_AGAIN) { + pam_syslog(pamh, LOG_CRIT, + "auth could not identify password for [%s]", name); + } else { + D(("conversation function is not ready yet")); + /* + * it is safe to resume this function so we translate this + * retval to the value that indicates we're happy to resume. + */ + retval = PAM_INCOMPLETE; + } + name = NULL; + AUTH_RETURN; + } + D(("user=%s, password=[%s]", name, p)); + + /* verify the password of this user */ + retval = _unix_verify_password(pamh, name, p, ctrl); + name = p = NULL; + + AUTH_RETURN; +} + + +/* + * The only thing _pam_set_credentials_unix() does is initialization of + * UNIX group IDs. + * + * Well, everybody but me on linux-pam is convinced that it should not + * initialize group IDs, so I am not doing it but don't say that I haven't + * warned you. -- AOY + */ + +PAM_EXTERN int +pam_sm_setcred (pam_handle_t *pamh, int flags UNUSED, + int argc UNUSED, const char **argv UNUSED) +{ + int retval; + const void *pretval = NULL; + + D(("called.")); + + retval = PAM_SUCCESS; + + D(("recovering return code from auth call")); + /* We will only find something here if UNIX_LIKE_AUTH is set -- + don't worry about an explicit check of argv. */ + if (pam_get_data(pamh, "unix_setcred_return", &pretval) == PAM_SUCCESS + && pretval) { + retval = *(const int *)pretval; + pam_set_data(pamh, "unix_setcred_return", NULL, NULL); + D(("recovered data indicates that old retval was %d", retval)); + } + + return retval; +} + +#ifdef PAM_STATIC +struct pam_module _pam_unix_auth_modstruct = { + "pam_unix_auth", + pam_sm_authenticate, + pam_sm_setcred, + NULL, + NULL, + NULL, + NULL, +}; +#endif |