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Diffstat (limited to 'openvpn/plugin/auth-pam/auth-pam.c')
-rw-r--r--openvpn/plugin/auth-pam/auth-pam.c755
1 files changed, 0 insertions, 755 deletions
diff --git a/openvpn/plugin/auth-pam/auth-pam.c b/openvpn/plugin/auth-pam/auth-pam.c
deleted file mode 100644
index 5047b34..0000000
--- a/openvpn/plugin/auth-pam/auth-pam.c
+++ /dev/null
@@ -1,755 +0,0 @@
-/*
- * OpenVPN -- An application to securely tunnel IP networks
- * over a single TCP/UDP port, with support for SSL/TLS-based
- * session authentication and key exchange,
- * packet encryption, packet authentication, and
- * packet compression.
- *
- * Copyright (C) 2002-2005 OpenVPN Solutions LLC <info@openvpn.net>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2
- * as published by the Free Software Foundation.
- *
- * 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 (see the file COPYING included with this
- * distribution); if not, write to the Free Software Foundation, Inc.,
- * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- */
-
-/*
- * OpenVPN plugin module to do PAM authentication using a split
- * privilege model.
- */
-
-#if DLOPEN_PAM
-#include <dlfcn.h>
-#include "pamdl.h"
-#else
-#include <security/pam_appl.h>
-#endif
-
-#include <stdio.h>
-#include <string.h>
-#include <ctype.h>
-#include <unistd.h>
-#include <stdlib.h>
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <sys/wait.h>
-#include <fcntl.h>
-#include <signal.h>
-#include <syslog.h>
-
-#include "openvpn-plugin.h"
-
-#define DEBUG(verb) ((verb) >= 7)
-
-/* Command codes for foreground -> background communication */
-#define COMMAND_VERIFY 0
-#define COMMAND_EXIT 1
-
-/* Response codes for background -> foreground communication */
-#define RESPONSE_INIT_SUCCEEDED 10
-#define RESPONSE_INIT_FAILED 11
-#define RESPONSE_VERIFY_SUCCEEDED 12
-#define RESPONSE_VERIFY_FAILED 13
-
-/*
- * Plugin state, used by foreground
- */
-struct auth_pam_context
-{
- /* Foreground's socket to background process */
- int foreground_fd;
-
- /* Process ID of background process */
- pid_t background_pid;
-
- /* Verbosity level of OpenVPN */
- int verb;
-};
-
-/*
- * Name/Value pairs for conversation function.
- * Special Values:
- *
- * "USERNAME" -- substitute client-supplied username
- * "PASSWORD" -- substitute client-specified password
- */
-
-#define N_NAME_VALUE 16
-
-struct name_value {
- const char *name;
- const char *value;
-};
-
-struct name_value_list {
- int len;
- struct name_value data[N_NAME_VALUE];
-};
-
-/*
- * Used to pass the username/password
- * to the PAM conversation function.
- */
-struct user_pass {
- int verb;
-
- char username[128];
- char password[128];
-
- const struct name_value_list *name_value_list;
-};
-
-/* Background process function */
-static void pam_server (int fd, const char *service, int verb, const struct name_value_list *name_value_list);
-
-/*
- * Given an environmental variable name, search
- * the envp array for its value, returning it
- * if found or NULL otherwise.
- */
-static const char *
-get_env (const char *name, const char *envp[])
-{
- if (envp)
- {
- int i;
- const int namelen = strlen (name);
- for (i = 0; envp[i]; ++i)
- {
- if (!strncmp (envp[i], name, namelen))
- {
- const char *cp = envp[i] + namelen;
- if (*cp == '=')
- return cp + 1;
- }
- }
- }
- return NULL;
-}
-
-/*
- * Return the length of a string array
- */
-static int
-string_array_len (const char *array[])
-{
- int i = 0;
- if (array)
- {
- while (array[i])
- ++i;
- }
- return i;
-}
-
-/*
- * Socket read/write functions.
- */
-
-static int
-recv_control (int fd)
-{
- unsigned char c;
- const ssize_t size = read (fd, &c, sizeof (c));
- if (size == sizeof (c))
- return c;
- else
- {
- /*fprintf (stderr, "AUTH-PAM: DEBUG recv_control.read=%d\n", (int)size);*/
- return -1;
- }
-}
-
-static int
-send_control (int fd, int code)
-{
- unsigned char c = (unsigned char) code;
- const ssize_t size = write (fd, &c, sizeof (c));
- if (size == sizeof (c))
- return (int) size;
- else
- return -1;
-}
-
-static int
-recv_string (int fd, char *buffer, int len)
-{
- if (len > 0)
- {
- ssize_t size;
- memset (buffer, 0, len);
- size = read (fd, buffer, len);
- buffer[len-1] = 0;
- if (size >= 1)
- return (int)size;
- }
- return -1;
-}
-
-static int
-send_string (int fd, const char *string)
-{
- const int len = strlen (string) + 1;
- const ssize_t size = write (fd, string, len);
- if (size == len)
- return (int) size;
- else
- return -1;
-}
-
-/*
- * Daemonize if "daemon" env var is true.
- * Preserve stderr across daemonization if
- * "daemon_log_redirect" env var is true.
- */
-static void
-daemonize (const char *envp[])
-{
- const char *daemon_string = get_env ("daemon", envp);
- if (daemon_string && daemon_string[0] == '1')
- {
- const char *log_redirect = get_env ("daemon_log_redirect", envp);
- int fd = -1;
- if (log_redirect && log_redirect[0] == '1')
- fd = dup (2);
- if (daemon (0, 0) < 0)
- {
- fprintf (stderr, "AUTH-PAM: daemonization failed\n");
- }
- else if (fd >= 3)
- {
- dup2 (fd, 2);
- close (fd);
- }
- }
-}
-
-/*
- * Close most of parent's fds.
- * Keep stdin/stdout/stderr, plus one
- * other fd which is presumed to be
- * our pipe back to parent.
- * Admittedly, a bit of a kludge,
- * but posix doesn't give us a kind
- * of FD_CLOEXEC which will stop
- * fds from crossing a fork().
- */
-static void
-close_fds_except (int keep)
-{
- int i;
- closelog ();
- for (i = 3; i <= 100; ++i)
- {
- if (i != keep)
- close (i);
- }
-}
-
-/*
- * Usually we ignore signals, because our parent will
- * deal with them.
- */
-static void
-set_signals (void)
-{
- signal (SIGTERM, SIG_DFL);
-
- signal (SIGINT, SIG_IGN);
- signal (SIGHUP, SIG_IGN);
- signal (SIGUSR1, SIG_IGN);
- signal (SIGUSR2, SIG_IGN);
- signal (SIGPIPE, SIG_IGN);
-}
-
-/*
- * Return 1 if query matches match.
- */
-static int
-name_value_match (const char *query, const char *match)
-{
- while (!isalnum (*query))
- {
- if (*query == '\0')
- return 0;
- ++query;
- }
- return strncasecmp (match, query, strlen (match)) == 0;
-}
-
-OPENVPN_EXPORT openvpn_plugin_handle_t
-openvpn_plugin_open_v1 (unsigned int *type_mask, const char *argv[], const char *envp[])
-{
- pid_t pid;
- int fd[2];
-
- struct auth_pam_context *context;
- struct name_value_list name_value_list;
-
- const int base_parms = 2;
-
- /*
- * Allocate our context
- */
- context = (struct auth_pam_context *) calloc (1, sizeof (struct auth_pam_context));
- context->foreground_fd = -1;
-
- /*
- * Intercept the --auth-user-pass-verify callback.
- */
- *type_mask = OPENVPN_PLUGIN_MASK (OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY);
-
- /*
- * Make sure we have two string arguments: the first is the .so name,
- * the second is the PAM service type.
- */
- if (string_array_len (argv) < base_parms)
- {
- fprintf (stderr, "AUTH-PAM: need PAM service parameter\n");
- goto error;
- }
-
- /*
- * See if we have optional name/value pairs to match against
- * PAM module queried fields in the conversation function.
- */
- name_value_list.len = 0;
- if (string_array_len (argv) > base_parms)
- {
- const int nv_len = string_array_len (argv) - base_parms;
- int i;
-
- if ((nv_len & 1) == 1 || (nv_len / 2) > N_NAME_VALUE)
- {
- fprintf (stderr, "AUTH-PAM: bad name/value list length\n");
- goto error;
- }
-
- name_value_list.len = nv_len / 2;
- for (i = 0; i < name_value_list.len; ++i)
- {
- const int base = base_parms + i * 2;
- name_value_list.data[i].name = argv[base];
- name_value_list.data[i].value = argv[base+1];
- }
- }
-
- /*
- * Get verbosity level from environment
- */
- {
- const char *verb_string = get_env ("verb", envp);
- if (verb_string)
- context->verb = atoi (verb_string);
- }
-
- /*
- * Make a socket for foreground and background processes
- * to communicate.
- */
- if (socketpair (PF_UNIX, SOCK_DGRAM, 0, fd) == -1)
- {
- fprintf (stderr, "AUTH-PAM: socketpair call failed\n");
- goto error;
- }
-
- /*
- * Fork off the privileged process. It will remain privileged
- * even after the foreground process drops its privileges.
- */
- pid = fork ();
-
- if (pid)
- {
- int status;
-
- /*
- * Foreground Process
- */
-
- context->background_pid = pid;
-
- /* close our copy of child's socket */
- close (fd[1]);
-
- /* don't let future subprocesses inherit child socket */
- if (fcntl (fd[0], F_SETFD, FD_CLOEXEC) < 0)
- fprintf (stderr, "AUTH-PAM: Set FD_CLOEXEC flag on socket file descriptor failed\n");
-
- /* wait for background child process to initialize */
- status = recv_control (fd[0]);
- if (status == RESPONSE_INIT_SUCCEEDED)
- {
- context->foreground_fd = fd[0];
- return (openvpn_plugin_handle_t) context;
- }
- }
- else
- {
- /*
- * Background Process
- */
-
- /* close all parent fds except our socket back to parent */
- close_fds_except (fd[1]);
-
- /* Ignore most signals (the parent will receive them) */
- set_signals ();
-
- /* Daemonize if --daemon option is set. */
- daemonize (envp);
-
- /* execute the event loop */
- pam_server (fd[1], argv[1], context->verb, &name_value_list);
-
- close (fd[1]);
-
- exit (0);
- return 0; /* NOTREACHED */
- }
-
- error:
- if (context)
- free (context);
- return NULL;
-}
-
-OPENVPN_EXPORT int
-openvpn_plugin_func_v1 (openvpn_plugin_handle_t handle, const int type, const char *argv[], const char *envp[])
-{
- struct auth_pam_context *context = (struct auth_pam_context *) handle;
-
- if (type == OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY && context->foreground_fd >= 0)
- {
- /* get username/password from envp string array */
- const char *username = get_env ("username", envp);
- const char *password = get_env ("password", envp);
-
- if (username && strlen (username) > 0 && password)
- {
- if (send_control (context->foreground_fd, COMMAND_VERIFY) == -1
- || send_string (context->foreground_fd, username) == -1
- || send_string (context->foreground_fd, password) == -1)
- {
- fprintf (stderr, "AUTH-PAM: Error sending auth info to background process\n");
- }
- else
- {
- const int status = recv_control (context->foreground_fd);
- if (status == RESPONSE_VERIFY_SUCCEEDED)
- return OPENVPN_PLUGIN_FUNC_SUCCESS;
- if (status == -1)
- fprintf (stderr, "AUTH-PAM: Error receiving auth confirmation from background process\n");
- }
- }
- }
- return OPENVPN_PLUGIN_FUNC_ERROR;
-}
-
-OPENVPN_EXPORT void
-openvpn_plugin_close_v1 (openvpn_plugin_handle_t handle)
-{
- struct auth_pam_context *context = (struct auth_pam_context *) handle;
-
- if (DEBUG (context->verb))
- fprintf (stderr, "AUTH-PAM: close\n");
-
- if (context->foreground_fd >= 0)
- {
- /* tell background process to exit */
- if (send_control (context->foreground_fd, COMMAND_EXIT) == -1)
- fprintf (stderr, "AUTH-PAM: Error signaling background process to exit\n");
-
- /* wait for background process to exit */
- if (context->background_pid > 0)
- waitpid (context->background_pid, NULL, 0);
-
- close (context->foreground_fd);
- context->foreground_fd = -1;
- }
-
- free (context);
-}
-
-OPENVPN_EXPORT void
-openvpn_plugin_abort_v1 (openvpn_plugin_handle_t handle)
-{
- struct auth_pam_context *context = (struct auth_pam_context *) handle;
-
- /* tell background process to exit */
- if (context->foreground_fd >= 0)
- {
- send_control (context->foreground_fd, COMMAND_EXIT);
- close (context->foreground_fd);
- context->foreground_fd = -1;
- }
-}
-
-/*
- * PAM conversation function
- */
-static int
-my_conv (int n, const struct pam_message **msg_array,
- struct pam_response **response_array, void *appdata_ptr)
-{
- const struct user_pass *up = ( const struct user_pass *) appdata_ptr;
- struct pam_response *aresp;
- int i;
- int ret = PAM_SUCCESS;
-
- *response_array = NULL;
-
- if (n <= 0 || n > PAM_MAX_NUM_MSG)
- return (PAM_CONV_ERR);
- if ((aresp = calloc (n, sizeof *aresp)) == NULL)
- return (PAM_BUF_ERR);
-
- /* loop through each PAM-module query */
- for (i = 0; i < n; ++i)
- {
- const struct pam_message *msg = msg_array[i];
- aresp[i].resp_retcode = 0;
- aresp[i].resp = NULL;
-
- if (DEBUG (up->verb))
- {
- fprintf (stderr, "AUTH-PAM: BACKGROUND: my_conv[%d] query='%s' style=%d\n",
- i,
- msg->msg ? msg->msg : "NULL",
- msg->msg_style);
- }
-
- if (up->name_value_list && up->name_value_list->len > 0)
- {
- /* use name/value list match method */
- const struct name_value_list *list = up->name_value_list;
- int j;
-
- /* loop through name/value pairs */
- for (j = 0; j < list->len; ++j)
- {
- const char *match_name = list->data[j].name;
- const char *match_value = list->data[j].value;
-
- if (name_value_match (msg->msg, match_name))
- {
- /* found name/value match */
- const char *return_value = NULL;
-
- if (DEBUG (up->verb))
- fprintf (stderr, "AUTH-PAM: BACKGROUND: name match found, query/match-string ['%s', '%s'] = '%s'\n",
- msg->msg,
- match_name,
- match_value);
-
- if (!strcmp (match_value, "USERNAME"))
- return_value = up->username;
- else if (!strcmp (match_value, "PASSWORD"))
- return_value = up->password;
- else
- return_value = match_value;
-
- aresp[i].resp = strdup (return_value);
- if (aresp[i].resp == NULL)
- ret = PAM_CONV_ERR;
- break;
- }
- }
-
- if (j == list->len)
- ret = PAM_CONV_ERR;
- }
- else
- {
- /* use PAM_PROMPT_ECHO_x hints */
- switch (msg->msg_style)
- {
- case PAM_PROMPT_ECHO_OFF:
- aresp[i].resp = strdup (up->password);
- if (aresp[i].resp == NULL)
- ret = PAM_CONV_ERR;
- break;
-
- case PAM_PROMPT_ECHO_ON:
- aresp[i].resp = strdup (up->username);
- if (aresp[i].resp == NULL)
- ret = PAM_CONV_ERR;
- break;
-
- case PAM_ERROR_MSG:
- case PAM_TEXT_INFO:
- break;
-
- default:
- ret = PAM_CONV_ERR;
- break;
- }
- }
- }
-
- if (ret == PAM_SUCCESS)
- *response_array = aresp;
- return ret;
-}
-
-/*
- * Return 1 if authenticated and 0 if failed.
- * Called once for every username/password
- * to be authenticated.
- */
-static int
-pam_auth (const char *service, const struct user_pass *up)
-{
- struct pam_conv conv;
- pam_handle_t *pamh = NULL;
- int status = PAM_SUCCESS;
- int ret = 0;
- const int name_value_list_provided = (up->name_value_list && up->name_value_list->len > 0);
-
- /* Initialize PAM */
- conv.conv = my_conv;
- conv.appdata_ptr = (void *)up;
- status = pam_start (service, name_value_list_provided ? NULL : up->username, &conv, &pamh);
- if (status == PAM_SUCCESS)
- {
- /* Call PAM to verify username/password */
- status = pam_authenticate(pamh, 0);
- if (status == PAM_SUCCESS)
- status = pam_acct_mgmt (pamh, 0);
- if (status == PAM_SUCCESS)
- ret = 1;
-
- /* Output error message if failed */
- if (!ret)
- {
- fprintf (stderr, "AUTH-PAM: BACKGROUND: user '%s' failed to authenticate: %s\n",
- up->username,
- pam_strerror (pamh, status));
- }
-
- /* Close PAM */
- pam_end (pamh, status);
- }
-
- return ret;
-}
-
-/*
- * Background process -- runs with privilege.
- */
-static void
-pam_server (int fd, const char *service, int verb, const struct name_value_list *name_value_list)
-{
- struct user_pass up;
- int command;
-#if DLOPEN_PAM
- static const char pam_so[] = "libpam.so";
-#endif
-
- /*
- * Do initialization
- */
- if (DEBUG (verb))
- fprintf (stderr, "AUTH-PAM: BACKGROUND: INIT service='%s'\n", service);
-
-#if DLOPEN_PAM
- /*
- * Load PAM shared object
- */
- if (!dlopen_pam (pam_so))
- {
- fprintf (stderr, "AUTH-PAM: BACKGROUND: could not load PAM lib %s: %s\n", pam_so, dlerror());
- send_control (fd, RESPONSE_INIT_FAILED);
- goto done;
- }
-#endif
-
- /*
- * Tell foreground that we initialized successfully
- */
- if (send_control (fd, RESPONSE_INIT_SUCCEEDED) == -1)
- {
- fprintf (stderr, "AUTH-PAM: BACKGROUND: write error on response socket [1]\n");
- goto done;
- }
-
- /*
- * Event loop
- */
- while (1)
- {
- memset (&up, 0, sizeof (up));
- up.verb = verb;
- up.name_value_list = name_value_list;
-
- /* get a command from foreground process */
- command = recv_control (fd);
-
- if (DEBUG (verb))
- fprintf (stderr, "AUTH-PAM: BACKGROUND: received command code: %d\n", command);
-
- switch (command)
- {
- case COMMAND_VERIFY:
- if (recv_string (fd, up.username, sizeof (up.username)) == -1
- || recv_string (fd, up.password, sizeof (up.password)) == -1)
- {
- fprintf (stderr, "AUTH-PAM: BACKGROUND: read error on command channel: code=%d, exiting\n",
- command);
- goto done;
- }
-
- if (DEBUG (verb))
- fprintf (stderr, "AUTH-PAM: BACKGROUND: USER/PASS: %s/%s\n",
- up.username, up.password);
-
- if (pam_auth (service, &up)) /* Succeeded */
- {
- if (send_control (fd, RESPONSE_VERIFY_SUCCEEDED) == -1)
- {
- fprintf (stderr, "AUTH-PAM: BACKGROUND: write error on response socket [2]\n");
- goto done;
- }
- }
- else /* Failed */
- {
- if (send_control (fd, RESPONSE_VERIFY_FAILED) == -1)
- {
- fprintf (stderr, "AUTH-PAM: BACKGROUND: write error on response socket [3]\n");
- goto done;
- }
- }
- break;
-
- case COMMAND_EXIT:
- goto done;
-
- case -1:
- fprintf (stderr, "AUTH-PAM: BACKGROUND: read error on command channel\n");
- goto done;
-
- default:
- fprintf (stderr, "AUTH-PAM: BACKGROUND: unknown command code: code=%d, exiting\n",
- command);
- goto done;
- }
- }
- done:
-
-#if DLOPEN_PAM
- dlclose_pam ();
-#endif
- if (DEBUG (verb))
- fprintf (stderr, "AUTH-PAM: BACKGROUND: EXIT\n");
-
- return;
-}
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