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/*
* Implements the PAM password group API (pam_sm_chauthtok).
*
* Copyright 2005, 2006, 2007, 2008, 2009 Russ Allbery <rra@stanford.edu>
* Copyright 2005 Andres Salomon <dilinger@debian.org>
* Copyright 1999, 2000 Frank Cusack <fcusack@fcusack.com>
*
* See LICENSE for licensing terms.
*/
/* Get declarations for the password functions. */
#define PAM_SM_PASSWORD
#include <config.h>
#include <portable/pam.h>
#include <errno.h>
#include <string.h>
#include <internal.h>
/*
* The main PAM interface for password changing.
*/
int
pam_sm_chauthtok(pam_handle_t *pamh, int flags, int argc, const char **argv)
{
struct context *ctx = NULL;
struct pam_args *args;
int pamret = PAM_SUCCESS;
int status;
PAM_CONST char *user;
char *pass = NULL;
args = pamk5_args_parse(pamh, flags, argc, argv);
if (args == NULL) {
pamk5_crit(NULL, "cannot allocate memory: %s", strerror(errno));
pamret = PAM_AUTHTOK_ERR;
goto done;
}
pamret = pamk5_context_fetch(args);
ENTRY(args, flags);
/* We only support password changes. */
if (!(flags & PAM_UPDATE_AUTHTOK) && !(flags & PAM_PRELIM_CHECK)) {
pamk5_err(args, "invalid pam_chauthtok flags %d", flags);
pamret = PAM_AUTHTOK_ERR;
goto done;
}
/*
* Check whether we should ignore this user.
*
* If we do ignore this user, and we're not in the preliminary check
* phase, still prompt the user for the new password, but suppress our
* banner. This is a little strange, but it allows another module to be
* stacked behind pam-krb5 with use_authtok and have it still work for
* ignored users.
*
* We ignore the return status when prompting for the new password in this
* case. The worst thing that can happen is to fail to get the password,
* in which case the other module will fail (or might even not care).
*/
if (args->ignore_root || args->minimum_uid > 0) {
status = pam_get_user(pamh, &user, NULL);
if (status == PAM_SUCCESS && pamk5_should_ignore(args, user)) {
if (flags & PAM_UPDATE_AUTHTOK) {
if (args->banner != NULL) {
free(args->banner);
args->banner = NULL;
}
pamk5_password_prompt(args, NULL);
}
pamret = PAM_IGNORE;
goto done;
}
}
/*
* If we weren't able to find an existing context to use, we're going
* into this fresh and need to create a new context.
*/
if (args->ctx == NULL) {
pamret = pamk5_context_new(args);
if (pamret != PAM_SUCCESS) {
pamk5_debug_pam(args, pamret, "creating context failed");
pamret = PAM_AUTHTOK_ERR;
goto done;
}
pamret = pam_set_data(pamh, "pam_krb5", args->ctx,
pamk5_context_destroy);
if (pamret != PAM_SUCCESS) {
pamk5_err_pam(args, pamret, "cannot set context data");
pamret = PAM_AUTHTOK_ERR;
goto done;
}
}
ctx = args->ctx;
/* Tell the user what's going on if we're handling an expiration. */
if (ctx->expired && ctx->creds == NULL)
pamk5_conv(args, "Password expired. You must change it now.",
PAM_TEXT_INFO, NULL);
/*
* Do the password change. This may only get tickets if we're doing the
* preliminary check phase.
*/
pamret = pamk5_password_change(args, !(flags & PAM_UPDATE_AUTHTOK));
if (!(flags & PAM_UPDATE_AUTHTOK))
goto done;
/*
* If we were handling a password change for an expired password, now
* try to get a ticket cache with the new password.
*/
if (pamret == PAM_SUCCESS && ctx->expired) {
krb5_creds *creds = NULL;
pamk5_debug(args, "obtaining credentials with new password");
args->force_first_pass = 1;
pamret = pamk5_password_auth(args, NULL, &creds);
if (pamret != PAM_SUCCESS)
goto done;
pamret = pamk5_cache_init_random(args, creds);
}
done:
if (pamret != PAM_SUCCESS) {
if (pamret == PAM_SERVICE_ERR || pamret == PAM_AUTH_ERR)
pamret = PAM_AUTHTOK_ERR;
if (pamret == PAM_AUTHINFO_UNAVAIL)
pamret = PAM_AUTHTOK_ERR;
}
EXIT(args, pamret);
if (pass != NULL) {
memset(pass, 0, strlen(pass));
free(pass);
}
pamk5_args_free(args);
return pamret;
}
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