shadow/libmisc/pam_pass_non_interactive.c

/*
 * SPDX-FileCopyrightText: 2009 - 2010, Nicolas François
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#include <config.h>

#ident "$Id:$"

#ifdef USE_PAM
#include <assert.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <security/pam_appl.h>
#include "prototypes.h"
#include "shadowlog.h"

/*@null@*/ /*@only@*/static const char *non_interactive_password = NULL;
static int ni_conv (int num_msg,
                    const struct pam_message **msg,
                    struct pam_response **resp,
                    unused void *appdata_ptr);
static struct pam_conv non_interactive_pam_conv = {
	ni_conv,
	NULL
};



static int ni_conv (int num_msg,
                    const struct pam_message **msg,
                    struct pam_response **resp,
                    unused void *appdata_ptr)
{
	struct pam_response *responses;
	int count;

	assert (NULL != non_interactive_password);

	if (num_msg <= 0) {
		return PAM_CONV_ERR;
	}

	responses = (struct pam_response *) calloc ((size_t) num_msg,
	                                            sizeof (*responses));
	if (NULL == responses) {
		return PAM_CONV_ERR;
	}

	for (count=0; count < num_msg; count++) {
		responses[count].resp_retcode = 0;

		switch (msg[count]->msg_style) {
		case PAM_PROMPT_ECHO_ON:
			fprintf (log_get_logfd(),
			         _("%s: PAM modules requesting echoing are not supported.\n"),
			         log_get_progname());
			goto failed_conversation;
		case PAM_PROMPT_ECHO_OFF:
			responses[count].resp = strdup (non_interactive_password);
			if (NULL == responses[count].resp) {
				goto failed_conversation;
			}
			break;
		case PAM_ERROR_MSG:
			if (   (NULL == msg[count]->msg)
			    || (fprintf (log_get_logfd(), "%s\n", msg[count]->msg) <0)) {
				goto failed_conversation;
			}
			responses[count].resp = NULL;
			break;
		case PAM_TEXT_INFO:
			if (   (NULL == msg[count]->msg)
			    || (fprintf (stdout, "%s\n", msg[count]->msg) <0)) {
				goto failed_conversation;
			}
			responses[count].resp = NULL;
			break;
		default:
			(void) fprintf (log_get_logfd(),
			                _("%s: conversation type %d not supported.\n"),
			                log_get_progname(), msg[count]->msg_style);
			goto failed_conversation;
		}
	}

	*resp = responses;

	return PAM_SUCCESS;

failed_conversation:
	for (count=0; count < num_msg; count++) {
		if (NULL != responses[count].resp) {
			memset (responses[count].resp, 0,
			        strlen (responses[count].resp));
			free (responses[count].resp);
			responses[count].resp = NULL;
		}
	}

	free (responses);
	*resp = NULL;

	return PAM_CONV_ERR;
}


/*
 * Change non interactively the user's password using PAM.
 *
 * Return 0 on success, 1 on failure.
 */
int do_pam_passwd_non_interactive (const char *pam_service,
                                    const char *username,
                                    const char* password)
{
	pam_handle_t *pamh = NULL;
	int ret;

	ret = pam_start (pam_service, username, &non_interactive_pam_conv, &pamh);
	if (ret != PAM_SUCCESS) {
		fprintf (log_get_logfd(),
		         _("%s: (user %s) pam_start failure %d\n"),
		         log_get_progname(), username, ret);
		return 1;
	}

	non_interactive_password = password;
	ret = pam_chauthtok (pamh, 0);
	if (ret != PAM_SUCCESS) {
		fprintf (log_get_logfd(),
		         _("%s: (user %s) pam_chauthtok() failed, error:\n"
		           "%s\n"),
		         log_get_progname(), username, pam_strerror (pamh, ret));
	}

	(void) pam_end (pamh, PAM_SUCCESS);

	return ((PAM_SUCCESS == ret) ? 0 : 1);
}
#else				/* !USE_PAM */
extern int errno;		/* warning: ANSI C forbids an empty source file */
#endif				/* !USE_PAM */