Allow the user to change their password if expired on AIX.

Bug #883

diff --git a/plugins/sudoers/auth/aix_auth.c b/plugins/sudoers/auth/aix_auth.c
index 41d40941ebaf05fe1a15e25547d3992705418761..b40382c52061664763aa56b59f1d97aabeceb09a 100644 (file)
--- a/plugins/sudoers/auth/aix_auth.c
+++ b/plugins/sudoers/auth/aix_auth.c
@@ -30,6 +30,7 @@
 #ifdef HAVE_AIXAUTH
 
 #include <sys/types.h>
+#include <sys/wait.h>
 #include <stdio.h>
 #include <stdlib.h>
 #ifdef HAVE_STRING_H
@@ -40,7 +41,9 @@
 #endif /* HAVE_STRING_H */
 #include <unistd.h>
 #include <ctype.h>
+#include <errno.h>
 #include <pwd.h>
+#include <signal.h>
 #include <usersec.h>
 
 #include "sudoers.h"
@@ -169,6 +172,67 @@ sudo_aix_valid_message(const char *message)
     debug_return_bool(true);
 }
 
+/* 
+ * Change the user's password.  If root changes the user's password
+ * the ADMCHG flag is set on the account (and the user must change
+ * it again) so we run passwd(1) as the user.  This does mean that
+ * the user will need to re-enter their original password again,
+ * unlike with su(1).  We may consider using pwdadm(1) as root to
+ * change the password and then clear the flag in the future.
+ */
+static bool
+sudo_aix_change_password(const char *user)
+{
+    struct sigaction sa, savechld;
+    pid_t child, pid;
+    bool ret = false;
+    sigset_t mask;
+    int status;
+    debug_decl(sudo_aix_change_password, SUDOERS_DEBUG_AUTH)
+
+    /* Set SIGCHLD handler to default since we call waitpid() below. */
+    memset(&sa, 0, sizeof(sa));                
+    sigemptyset(&sa.sa_mask);
+    sa.sa_flags = SA_RESTART;     
+    sa.sa_handler = SIG_DFL;
+    (void) sigaction(SIGCHLD, &sa, &savechld);
+
+    switch (child = sudo_debug_fork()) {
+    case -1:
+       /* error */
+       sudo_warn(U_("unable to fork"));
+       break;
+    case 0:
+       /* child, run passwd(1) */
+       sigemptyset(&mask);
+       sigaddset(&mask, SIGINT);
+       sigaddset(&mask, SIGQUIT);
+       (void) sigprocmask(SIG_UNBLOCK, &mask, NULL);
+       set_perms(PERM_USER);
+       execl("/usr/bin/passwd", "passwd", user, (char *)NULL);
+       sudo_warn("passwd");
+       _exit(127);
+       /* NOTREACHED */
+    default:
+       /* parent */
+       break;
+    }
+
+    /* Wait for passwd(1) to complete. */
+    do {
+       pid = waitpid(child, &status, 0);
+    } while (pid == -1 && errno == EINTR);
+    sudo_debug_printf(SUDO_DEBUG_INFO|SUDO_DEBUG_LINENO,
+       "child (%d) exit value %d", (int)child, status);
+    if (pid != -1 && WIFEXITED(status) && WEXITSTATUS(status) == 0)
+       ret = true;
+
+    /* Restore saved SIGCHLD handler. */
+    (void) sigaction(SIGCHLD, &savechld, NULL);
+
+    debug_return_bool(ret);
+}
+
 int
 sudo_aix_verify(struct passwd *pw, char *prompt, sudo_auth *auth, struct sudo_conv_callback *callback)
 {
@@ -196,6 +260,40 @@ sudo_aix_verify(struct passwd *pw, char *prompt, sudo_auth *auth, struct sudo_co
        ret = pass ? AUTH_FAILURE : AUTH_INTR;
     }
     free(message);
+    message = NULL;
+
+    /* Check if password expired and allow user to change it if possible. */
+    if (ret == AUTH_SUCCESS) {
+       result = passwdexpired(pw->pw_name, &message);
+       if (message != NULL && message[0] != '\0') {
+           sudo_printf(result ? SUDO_CONV_ERROR_MSG : SUDO_CONV_INFO_MSG,
+               "%s", message);
+           free(message);
+           message = NULL;
+       }
+       switch (result) {
+       case 0:
+           /* password not expired. */
+           break;
+       case 1:
+           /* password expired, user must change it */
+           if (!sudo_aix_change_password(pw->pw_name)) {
+               sudo_warnx(U_("unable to change password for %s"), pw->pw_name);
+               ret = AUTH_FATAL;
+           }
+           break;
+       case 2:
+           /* password expired, only admin can change it */
+           ret = AUTH_FATAL;
+           break;
+       default:
+           /* error (-1) */
+           sudo_warn("passwdexpired");
+           ret = AUTH_FATAL;
+           break;
+       }
+    }
+
     debug_return_int(ret);
 }