From 907025eb40f2f940e34046a73d9664b05ac31eda Mon Sep 17 00:00:00 2001 From: nekral-guest Date: Thu, 16 Jun 2011 21:21:29 +0000 Subject: [PATCH] * src/su.c: environ is provided by . * src/su.c: Added function prototypes. * src/su.c: Rename shellstr parameter to shellname to avoid collision with static variable. * NEWS, src/su.c: Added support for PAM modules which change PAM_USER. --- ChangeLog | 9 ++++++++ NEWS | 2 ++ src/su.c | 63 ++++++++++++++++++++++++++++++++++++++++++------------- 3 files changed, 60 insertions(+), 14 deletions(-) diff --git a/ChangeLog b/ChangeLog index 04cd6789..0a62f68c 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,12 @@ +2011-06-16 Nicolas François + + * src/su.c: environ is provided by . + * src/su.c: Added function prototypes. + * src/su.c: Rename shellstr parameter to shellname to avoid + collision with static variable. + * NEWS, src/su.c: Added support for PAM modules which change + PAM_USER. + 2011-06-13 Nicolas François * src/su.c (prepare_pam_close_session): Extract the creation of a diff --git a/NEWS b/NEWS index 4a8c1608..f544a851 100644 --- a/NEWS +++ b/NEWS @@ -48,6 +48,7 @@ shadow-4.1.4.3 -> shadow-4.1.5 UNRELEASED caller's privileges. * Close PAM sessions as root. This will be more friendly to PAM modules like pam_mount or pam_systemd. + * Added support for PAM modules which change PAM_USER. - newgrp, sg, groupmems * Fix parsing of gshadow entries. - useradd @@ -67,6 +68,7 @@ shadow-4.1.4.3 -> shadow-4.1.5 UNRELEASED * Updated Czech translation. * Updated Danish translation. * Updated French translation. + * Updated French man pages translation. * Updated German translation. * Updated German man pages translation. * Updated Japanese translation. diff --git a/src/su.c b/src/su.c index 67c3e6a0..84ac42b9 100644 --- a/src/su.c +++ b/src/su.c @@ -115,13 +115,12 @@ static pid_t pid_child = 0; * External identifiers */ -extern char **newenvp; -extern char **environ; -extern size_t newenvc; +extern char **newenvp; /* libmisc/env.c */ +extern size_t newenvc; /* libmisc/env.c */ /* local function prototypes */ -static void execve_shell (const char *shellstr, +static void execve_shell (const char *shellname, char *args[], char *const envp[]); #ifdef USE_PAM @@ -131,6 +130,8 @@ static void prepare_pam_close_session (void); static RETSIGTYPE die (int); static bool iswheel (const char *); #endif /* !USE_PAM */ +static bool restricted_shell (const char *shellname); +static void su_failure (const char *tty, bool su_to_root); static struct passwd * check_perms (void); #ifdef USE_PAM static void check_perms_pam (struct passwd *pw); @@ -139,6 +140,7 @@ static void check_perms_nopam (struct passwd *pw); #endif /* !USE_PAM */ static void save_caller_context (char **argv); static void process_flags (int argc, char **argv); +static void set_environment (struct passwd *pw); #ifndef USE_PAM /* @@ -190,13 +192,13 @@ static RETSIGTYPE kill_child (int unused(s)) #endif /* USE_PAM */ /* borrowed from GNU sh-utils' "su.c" */ -static bool restricted_shell (const char *shellstr) +static bool restricted_shell (const char *shellname) { char *line; setusershell (); while ((line = getusershell ()) != NULL) { - if (('#' != *line) && (strcmp (line, shellstr) == 0)) { + if (('#' != *line) && (strcmp (line, shellname) == 0)) { endusershell (); return false; } @@ -224,15 +226,15 @@ static void su_failure (const char *tty, bool su_to_root) * execve_shell - Execute a shell with execve, or interpret it with * /bin/sh */ -static void execve_shell (const char *shellstr, +static void execve_shell (const char *shellname, char *args[], char *const envp[]) { int err; - (void) execve (shellstr, (char **) args, envp); + (void) execve (shellname, (char **) args, envp); err = errno; - if (access (shellstr, R_OK|X_OK) == 0) { + if (access (shellname, R_OK|X_OK) == 0) { /* * Assume this is a shell script (with no shebang). * Interpret it with /bin/sh @@ -245,7 +247,7 @@ static void execve_shell (const char *shellstr, targs = (char **) xmalloc ((n_args + 3) * sizeof (args[0])); targs[0] = "sh"; targs[1] = "-"; - targs[2] = xstrdup (shellstr); + targs[2] = xstrdup (shellname); targs[n_args+2] = NULL; while (1 != n_args) { targs[n_args+1] = args[n_args - 1]; @@ -570,24 +572,57 @@ static void check_perms_nopam (struct passwd *pw) */ static struct passwd * check_perms (void) { +#ifdef USE_PAM + const char *tmp_name; + int ret; +#endif /* !USE_PAM */ /* * The password file entries for the user is gotten and the account * validated. */ struct passwd *pw = xgetpwnam (name); if (NULL == pw) { - (void) fprintf (stderr, _("Unknown id: %s\n"), name); - closelog (); - exit (1); + (void) fprintf (stderr, + _("No passwd entry for user '%s'\n"), name); + SYSLOG ((LOG_ERR, "No passwd entry for user '%s'", name)); + su_failure (caller_tty, true); } (void) signal (SIGINT, SIG_IGN); (void) signal (SIGQUIT, SIG_IGN); + #ifdef USE_PAM check_perms_pam (pw); + /* PAM authentication can request a change of account */ + ret = pam_get_item(pamh, PAM_USER, (const void **) &tmp_name); + if (ret != PAM_SUCCESS) { + SYSLOG((LOG_ERR, "pam_get_item: internal PAM error\n")); + (void) fprintf (stderr, + "%s: Internal PAM error retrieving username\n", + Prog); + (void) pam_end (pamh, ret); + su_failure (caller_tty, 0 == pw->pw_uid); + } + if (strcmp (name, tmp_name) != 0) { + SYSLOG ((LOG_INFO, + "Change user from '%s' to '%s' as requested by PAM", + name, tmp_name)); + strncpy (name, tmp_name, sizeof(name) - 1); + name[sizeof(name) - 1] = '\0'; + pw = xgetpwnam (name); + if (NULL == pw) { + (void) fprintf (stderr, + _("No passwd entry for user '%s'\n"), + name); + SYSLOG ((LOG_ERR, + "No passwd entry for user '%s'", name)); + su_failure (caller_tty, true); + } + } #else /* !USE_PAM */ check_perms_nopam (pw); #endif /* !USE_PAM */ + (void) signal (SIGINT, SIG_DFL); (void) signal (SIGQUIT, SIG_DFL); @@ -659,7 +694,7 @@ static void save_caller_context (char **argv) Prog); SYSLOG ((LOG_WARN, "Cannot determine the user name of the caller (UID %lu)", (unsigned long) caller_uid)); - su_failure (caller_tty, true); // FIXME: at this time I do not know the target UID + su_failure (caller_tty, true); /* unknown target UID*/ } STRFCPY (caller_name, pw->pw_name);