commit af03c2323d74bd1c2d0e63ddf801e7af4c314aad
parent e15477fc4f2fe0e3370ab91cbe74b6352154a707
Author: Jan Pobříslo <ccx@te2000.cz>
Date: Fri, 8 Jan 2021 19:30:41 +0000
move login.c to separate directory so toybox sources can be included, fix null pwd reference
Diffstat:
| D | login.c | | | 226 | ------------------------------------------------------------------------------- |
| A | login/login.c | | | 229 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
2 files changed, 229 insertions(+), 226 deletions(-)
diff --git a/login.c b/login.c
@@ -1,226 +0,0 @@
-/* login.c - Start a session on the system.
- *
- * Copyright 2012 Elie De Brauwer <eliedebrauwer@gmail.com>
- *
- * No support for PAM/securetty/selinux/login script/issue/utmp
- * Relies on libcrypt for hash calculation.
- *
- * TODO: this command predates "pending" but needs cleanup. It #defines
- * random stuff, calls exit() form a signal handler... yeah.
-
-USE_LOGIN(NEWTOY(login, ">1f:ph:", TOYFLAG_BIN|TOYFLAG_NEEDROOT))
-
-config LOGIN
- bool "login"
- default y
- depends on TOYBOX_SHADOW
- help
- usage: login [-p] [-h host] [-f USERNAME] [USERNAME]
-
- Log in as a user, prompting for username and password if necessary.
-
- -p Preserve environment
- -h The name of the remote host for this login
- -f login as USERNAME without authentication
-*/
-
-#define FOR_login
-#include "toys.h"
-
-GLOBALS(
- char *hostname;
- char *username;
-
- int login_timeout, login_fail_timeout;
-)
-
-static void login_timeout_handler(int sig __attribute__((unused)))
-{
- printf("\nLogin timed out after %d seconds.\n", TT.login_timeout);
- exit(0);
-}
-
-void login_main(void)
-{
- char *forbid[] = {
- "BASH_ENV", "ENV", "HOME", "IFS", "LD_LIBRARY_PATH", "LD_PRELOAD",
- "LD_TRACE_LOADED_OBJECTS", "LD_BIND_NOW", "LD_AOUT_LIBRARY_PATH",
- "LD_AOUT_PRELOAD", "LD_NOWARN", "LD_KEEPDIR", "SHELL"
- };
- int hh = toys.optflags&FLAG_h, count, tty;
- int pipefd[2] = {-1, -1};
- int child_pid;
- char uu[33], *username, *pass = 0, *ss;
- struct passwd *pwd = 0;
- char *loginexec = 0;
- unsigned char use_loginexec = 0;
-
- for (tty=0; tty<3; tty++) if (isatty(tty)) break;
- if (tty == 3) error_exit("no tty");
-
- for (count = 0; count < ARRAY_LEN(forbid); count++) unsetenv(forbid[count]);
-
- openlog("login", LOG_PID | LOG_CONS, LOG_AUTH);
- xsignal(SIGALRM, login_timeout_handler);
-
- if (TT.username) username = TT.username;
- else username = *toys.optargs;
- for (count = 0; count < 3; count++) {
- alarm(TT.login_timeout = 60);
- tcflush(0, TCIFLUSH);
-
- if (!username) {
- int i;
-
- memset(username = uu, 0, sizeof(uu));
- gethostname(uu, sizeof(uu)-1);
- printf("%s%slogin: ", *uu ? uu : "", *uu ? " " : "");
- fflush(stdout);
-
- if(!fgets(uu, sizeof(uu)-1, stdin)) _exit(1);
-
- // Remove trailing \n and so on
- for (i = 0; i<sizeof(uu); i++) if (uu[i]<=' ' || uu[i]==':') uu[i]=0;
- if (!*uu) {
- username = 0;
- continue;
- }
- }
-
- // If user exists and isn't locked
- pwd = getpwnam(username);
- if (pwd && *pwd->pw_passwd != '!' && *pwd->pw_passwd != '*') {
-
- // Pre-authenticated or passwordless
- if (TT.username || !*pwd->pw_passwd) break;
-
- // fetch shadow password if necessary
- if (*(pass = pwd->pw_passwd) == 'x') {
- struct spwd *spwd = getspnam (username);
-
- if (spwd) pass = spwd->sp_pwdp;
- }
- } else if (TT.username) error_exit("bad -f '%s'", TT.username);
-
- loginexec = xmprintf("%s/loginexec", pwd->pw_dir);
- use_loginexec = !access(loginexec, X_OK);
-
- // Verify password. (Prompt for password _before_ checking disable state.)
- if (!read_password(toybuf, sizeof(toybuf), "Password: ")) {
- int x = pass && (ss = crypt(toybuf, pass)) && !strcmp(pass, ss);
-
- if (x && use_loginexec) {
- if(!pipe(pipefd)) {
- if((child_pid = fork())) {
- if(child_pid == -1) {
- /* error */
- perror("fork");
- close(pipefd[0]);
- close(pipefd[1]);
- pipefd[0] = pipefd[1] = -1;
- } else {
- /* parent */
- close(pipefd[1]);
- }
- } else {
- /* child */
- dup2(pipefd[1], 1);
- xprintf("%s\n", toybuf);
- exit(0);
- }
- } else {
- /* creating pipe failed */
- perror("pipe");
- pipefd[0] = pipefd[1] = -1;
- }
- if (!access("/etc/loginexec", X_OK)) {
- if (!(toys.optflags&FLAG_p)) {
- char *term = getenv("TERM");
-
- clearenv();
- if (term) setenv("TERM", term, 1);
- }
-
- setenv("USER", pwd->pw_name, 1);
- setenv("LOGNAME", pwd->pw_name, 1);
- setenv("HOME", pwd->pw_dir, 1);
- setenv("SHELL", pwd->pw_shell, 1);
- if(pipefd[0] >= 0) {
- setenv("LOGINPASS_FD", xmprintf("%d", pipefd[0]), 1);
- }
- /* TODO */
- /* set UID, GID and GIDLIST env variables */
-
- alarm(0); // remove pending SIGALRM for stale login
-
- execl("/etc/loginexec", "/etc/loginexec", loginexec, (char *)0);
- }
- }
- // password go bye-bye now.
- memset(toybuf, 0, sizeof(toybuf));
- if (x) break;
- }
-
- syslog(LOG_WARNING, "invalid password for '%s' on %s %s%s", pwd->pw_name,
- ttyname(tty), hh ? "from " : "", hh ? TT.hostname : "");
-
- sleep(3);
- puts("Login incorrect");
-
- username = 0;
- pwd = 0;
- }
-
- alarm(0);
- // This had password data in it, and we reuse for motd below
- memset(toybuf, 0, sizeof(toybuf));
-
- if (!pwd) error_exit("max retries (3)");
-
- // Check twice because "this file exists" is a security test, and in
- // theory filehandle exhaustion or other error could make open/read fail.
- if (pwd->pw_uid && !access("/etc/nologin", R_OK)) {
- ss = readfile("/etc/nologin", toybuf, sizeof(toybuf));
- puts ((ss && *ss) ? ss : "nologin");
- free(ss);
- toys.exitval = 1;
-
- return;
- }
-
- xsetuser(pwd);
-
- if (chdir(pwd->pw_dir)) printf("bad $HOME: %s\n", pwd->pw_dir);
-
- if (!(toys.optflags&FLAG_p)) {
- char *term = getenv("TERM");
-
- clearenv();
- if (term) setenv("TERM", term, 1);
- }
-
- setenv("USER", pwd->pw_name, 1);
- setenv("LOGNAME", pwd->pw_name, 1);
- setenv("HOME", pwd->pw_dir, 1);
- setenv("SHELL", pwd->pw_shell, 1);
- if(pipefd[0] >= 0) {
- setenv("LOGINPASS_FD", xmprintf("%d", pipefd[0]), 1);
- }
-
- // Message of the day
- if ((ss = readfile("/etc/motd", 0, 0))) {
- puts(ss);
- free(ss);
- }
-
- syslog(LOG_INFO, "%s logged in on %s %s %s", pwd->pw_name,
- ttyname(tty), hh ? "from" : "", hh ? TT.hostname : "");
-
- if(use_loginexec) {
- execl(loginexec, loginexec, (char *)0);
- } else {
- // not using xexec(), login calls absolute path from filesystem so must exec()
- execl(pwd->pw_shell, xmprintf("-%s", pwd->pw_shell), (char *)0);
- perror_exit("exec shell '%s'", pwd->pw_shell);
- }
-}
diff --git a/login/login.c b/login/login.c
@@ -0,0 +1,229 @@
+/* login.c - Start a session on the system.
+ *
+ * Copyright 2012 Elie De Brauwer <eliedebrauwer@gmail.com>
+ *
+ * No support for PAM/securetty/selinux/login script/issue/utmp
+ * Relies on libcrypt for hash calculation.
+ *
+ * TODO: this command predates "pending" but needs cleanup. It #defines
+ * random stuff, calls exit() form a signal handler... yeah.
+
+USE_LOGIN(NEWTOY(login, ">1f:ph:", TOYFLAG_BIN|TOYFLAG_NEEDROOT))
+
+config LOGIN
+ bool "login"
+ default y
+ depends on TOYBOX_SHADOW
+ help
+ usage: login [-p] [-h host] [-f USERNAME] [USERNAME]
+
+ Log in as a user, prompting for username and password if necessary.
+
+ -p Preserve environment
+ -h The name of the remote host for this login
+ -f login as USERNAME without authentication
+*/
+
+#define FOR_login
+#include "toys.h"
+
+GLOBALS(
+ char *hostname;
+ char *username;
+
+ int login_timeout, login_fail_timeout;
+)
+
+static void login_timeout_handler(int sig __attribute__((unused)))
+{
+ printf("\nLogin timed out after %d seconds.\n", TT.login_timeout);
+ exit(0);
+}
+
+void login_main(void)
+{
+ char *forbid[] = {
+ "BASH_ENV", "ENV", "HOME", "IFS", "LD_LIBRARY_PATH", "LD_PRELOAD",
+ "LD_TRACE_LOADED_OBJECTS", "LD_BIND_NOW", "LD_AOUT_LIBRARY_PATH",
+ "LD_AOUT_PRELOAD", "LD_NOWARN", "LD_KEEPDIR", "SHELL"
+ };
+ int hh = toys.optflags&FLAG_h, count, tty;
+ int pipefd[2] = {-1, -1};
+ int child_pid;
+ char uu[33], *username, *pass = 0, *ss;
+ struct passwd *pwd = 0;
+ char *loginexec = 0;
+ unsigned char use_loginexec = 0;
+
+ for (tty=0; tty<3; tty++) if (isatty(tty)) break;
+ if (tty == 3) error_exit("no tty");
+
+ for (count = 0; count < ARRAY_LEN(forbid); count++) unsetenv(forbid[count]);
+
+ openlog("login", LOG_PID | LOG_CONS, LOG_AUTH);
+ xsignal(SIGALRM, login_timeout_handler);
+
+ if (TT.username) username = TT.username;
+ else username = *toys.optargs;
+ for (count = 0; count < 3; count++) {
+ alarm(TT.login_timeout = 60);
+ tcflush(0, TCIFLUSH);
+
+ if (!username) {
+ int i;
+
+ memset(username = uu, 0, sizeof(uu));
+ gethostname(uu, sizeof(uu)-1);
+ printf("%s%slogin: ", *uu ? uu : "", *uu ? " " : "");
+ fflush(stdout);
+
+ if(!fgets(uu, sizeof(uu)-1, stdin)) _exit(1);
+
+ // Remove trailing \n and so on
+ for (i = 0; i<sizeof(uu); i++) if (uu[i]<=' ' || uu[i]==':') uu[i]=0;
+ if (!*uu) {
+ username = 0;
+ continue;
+ }
+ }
+
+ // If user exists and isn't locked
+ pwd = getpwnam(username);
+ if (pwd && *pwd->pw_passwd != '!' && *pwd->pw_passwd != '*') {
+
+ // Pre-authenticated or passwordless
+ if (TT.username || !*pwd->pw_passwd) break;
+
+ // fetch shadow password if necessary
+ if (*(pass = pwd->pw_passwd) == 'x') {
+ struct spwd *spwd = getspnam (username);
+
+ if (spwd) pass = spwd->sp_pwdp;
+ }
+
+ loginexec = xmprintf("%s/loginexec", pwd->pw_dir);
+ use_loginexec = !access(loginexec, X_OK);
+
+ } else if (TT.username) error_exit("bad -f '%s'", TT.username);
+
+
+ // Verify password. (Prompt for password _before_ checking disable state.)
+ if (!read_password(toybuf, sizeof(toybuf), "Password: ")) {
+ int x = pass && (ss = crypt(toybuf, pass)) && !strcmp(pass, ss);
+
+ if (x && use_loginexec) {
+ if(!pipe(pipefd)) {
+ if((child_pid = fork())) {
+ if(child_pid == -1) {
+ /* error */
+ perror("fork");
+ close(pipefd[0]);
+ close(pipefd[1]);
+ pipefd[0] = pipefd[1] = -1;
+ } else {
+ /* parent */
+ close(pipefd[1]);
+ }
+ } else {
+ /* child */
+ dup2(pipefd[1], 1);
+ xprintf("%s\n", toybuf);
+ exit(0);
+ }
+ } else {
+ /* creating pipe failed */
+ perror("pipe");
+ pipefd[0] = pipefd[1] = -1;
+ }
+ if (!access("/etc/loginexec", X_OK)) {
+ if (!(toys.optflags&FLAG_p)) {
+ char *term = getenv("TERM");
+
+ clearenv();
+ if (term) setenv("TERM", term, 1);
+ }
+
+ setenv("USER", pwd->pw_name, 1);
+ setenv("LOGNAME", pwd->pw_name, 1);
+ setenv("HOME", pwd->pw_dir, 1);
+ setenv("SHELL", pwd->pw_shell, 1);
+ if(pipefd[0] >= 0) {
+ setenv("LOGINPASS_FD", xmprintf("%d", pipefd[0]), 1);
+ }
+ /* TODO */
+ /* set UID, GID and GIDLIST env variables */
+
+ alarm(0); // remove pending SIGALRM for stale login
+
+ execl("/etc/loginexec", "/etc/loginexec", loginexec, (char *)0);
+ }
+ }
+ // password go bye-bye now.
+ memset(toybuf, 0, sizeof(toybuf));
+ if (x) break;
+ }
+
+ syslog(LOG_WARNING, "invalid password for '%s' on %s %s%s",
+ pwd ? pwd->pw_name : "UNKNOWN",
+ ttyname(tty), hh ? "from " : "", hh ? TT.hostname : "");
+
+ sleep(3);
+ puts("Login incorrect");
+
+ username = 0;
+ pwd = 0;
+ }
+
+ alarm(0);
+ // This had password data in it, and we reuse for motd below
+ memset(toybuf, 0, sizeof(toybuf));
+
+ if (!pwd) error_exit("max retries (3)");
+
+ // Check twice because "this file exists" is a security test, and in
+ // theory filehandle exhaustion or other error could make open/read fail.
+ if (pwd->pw_uid && !access("/etc/nologin", R_OK)) {
+ ss = readfile("/etc/nologin", toybuf, sizeof(toybuf));
+ puts ((ss && *ss) ? ss : "nologin");
+ free(ss);
+ toys.exitval = 1;
+
+ return;
+ }
+
+ xsetuser(pwd);
+
+ if (chdir(pwd->pw_dir)) printf("bad $HOME: %s\n", pwd->pw_dir);
+
+ if (!(toys.optflags&FLAG_p)) {
+ char *term = getenv("TERM");
+
+ clearenv();
+ if (term) setenv("TERM", term, 1);
+ }
+
+ setenv("USER", pwd->pw_name, 1);
+ setenv("LOGNAME", pwd->pw_name, 1);
+ setenv("HOME", pwd->pw_dir, 1);
+ setenv("SHELL", pwd->pw_shell, 1);
+ if(pipefd[0] >= 0) {
+ setenv("LOGINPASS_FD", xmprintf("%d", pipefd[0]), 1);
+ }
+
+ // Message of the day
+ if ((ss = readfile("/etc/motd", 0, 0))) {
+ puts(ss);
+ free(ss);
+ }
+
+ syslog(LOG_INFO, "%s logged in on %s %s %s", pwd->pw_name,
+ ttyname(tty), hh ? "from" : "", hh ? TT.hostname : "");
+
+ if(use_loginexec) {
+ execl(loginexec, loginexec, (char *)0);
+ } else {
+ // not using xexec(), login calls absolute path from filesystem so must exec()
+ execl(pwd->pw_shell, xmprintf("-%s", pwd->pw_shell), (char *)0);
+ perror_exit("exec shell '%s'", pwd->pw_shell);
+ }
+}
