2 * passprompt.c - pppd plugin to invoke an external PAP password prompter
4 * Copyright 1999 Paul Mackerras, Alan Curry.
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
16 #include <pppd/pppd.h>
18 char pppd_version[] = PPPD_VERSION;
20 static char promptprog[PATH_MAX+1];
21 static int promptprog_refused = 0;
23 static option_t options[] = {
24 { "promptprog", o_string, promptprog,
25 "External PAP password prompting program",
26 OPT_STATIC, NULL, PATH_MAX },
30 static int promptpass(char *user, char *passwd)
34 int readgood, wstat, ret;
37 if (promptprog_refused || promptprog[0] == 0 || access(promptprog, X_OK) < 0)
38 return -1; /* sorry, can't help */
44 warn("Can't make a pipe for %s", promptprog);
47 if ((kid = fork()) == (pid_t) -1) {
48 warn("Can't fork to run %s", promptprog);
54 /* we are the child, exec the program */
55 char *argv[5], fdstr[32];
59 ret = seteuid(getuid());
61 warn("Couldn't set effective user id");
63 ret = setegid(getgid());
65 warn("Couldn't set effective user id");
69 argv[2] = remote_name;
70 sprintf(fdstr, "%d", p[1]);
77 /* we are the parent, read the password from the pipe */
81 red = read(p[0], passwd + readgood, MAXSECRETLEN-1 - readgood);
85 if (errno == EINTR && !got_sigterm)
87 error("Can't read secret from %s: %m", promptprog);
92 } while (readgood < MAXSECRETLEN - 1);
95 /* now wait for child to exit */
96 while (waitpid(kid, &wstat, 0) < 0) {
97 if (errno != EINTR || got_sigterm) {
98 warn("error waiting for %s: %m", promptprog);
105 passwd[readgood] = 0;
106 if (!WIFEXITED(wstat))
107 warn("%s terminated abnormally", promptprog);
108 if (WEXITSTATUS(wstat)) {
109 warn("%s exited with code %d", promptprog, WEXITSTATUS(wstat));
110 /* code when cancel was hit in the prompt prog */
111 if (WEXITSTATUS(wstat) == 128) {
112 promptprog_refused = 1;
119 void plugin_init(void)
121 add_options(options);
122 pap_passwd_hook = promptpass;
123 #ifdef PPP_WITH_EAPTLS
124 eaptls_passwd_hook = promptpass;