Changeset 1042

Timestamp:

05/14/08 17:22:03 (7 months ago)

Author:

alonbl

Message:

Non privileged operation

As OpenCT is a security component, it best to use least privileged mode, and udev allows this now.
The attached patch allows users to run the ifdhandler as none root user.

The configuration file was modified, not the ifdhandler is a node in the following format:

#
# Path to ifdhandler
ifdhandler {

program = SBINDIR/ifdhandler;

# user = openctd;
# groups = {
# usb,
# };
};

I believe this place is correct, but if people want to keep backward compatibility I guess
this can be splitted, and keep current ifdhandler key.

The openct-control running from init.d script or udev rule script will fork the ifdhandler using
the specified user and set the context to the specified groups. There may be more than one
group as there are more than one device type.

It also set the /var/run/openct/status owner to the specified user.

M src/tools/openct-control.c
M src/ifd/utils.c
M src/ifd/init.c
M src/include/openct/openct.h
M src/ct/status.c
M etc/openct.conf.in

Location:

trunk

Files:

• etc/openct.conf.in (modified) (1 diff)
• src/ct/status.c (modified) (3 diffs)
• src/ifd/init.c (modified) (1 diff)
• src/ifd/utils.c (modified) (3 diffs)
• src/include/openct/openct.h (modified) (1 diff)
• src/tools/openct-control.c (modified) (2 diffs)

trunk/etc/openct.conf.in

@@ -4 +4 @@
 # Enable hot plugging
 hotplug = yes;
+
 #
 # Path to ifdhandler
-ifdhandler = SBINDIR/ifdhandler;
+ifdhandler {
+        program         = SBINDIR/ifdhandler;
+#       user            = openctd;
+#       groups = {
+#               usb,
+#       };
+};
 
 #

trunk/src/ct/status.c

@@ -11 +11 @@
 #include <sys/mman.h>
 #include <sys/stat.h>
+#include <sys/types.h>
+#include <pwd.h>
 #include <signal.h>
 #include <unistd.h>
@@ -62 +64 @@
 }
 
-int ct_status_clear(unsigned int count)
-{
-        int fd;
+int ct_status_clear(unsigned int count, const char *owner)
+{
+        int fd = -1;
         char status_path[PATH_MAX];
 
@@ -76 +78 @@
             || fchmod(fd, 0644) < 0) {
                 ct_error("cannot create %s: %m", status_path);
-                unlink(status_path);
-                if (fd >= 0)
-                        close(fd);
-                return -1;
+                goto error;
+        }
+
+        if (owner != NULL) {
+                struct passwd *p = getpwnam(owner);
+
+                if (p == NULL) {
+                        ct_error("cannot parse user %s", owner);
+                        goto error;
+                }
+
+                if (fchown(fd, p->pw_uid, -1) == -1) {
+                        ct_error("cannot chown %s to %s: %m", status_path, owner);
+                        goto error;
+                }
         }
 
         return 0;
+
+error:
+
+        unlink(status_path);
+        if (fd >= 0)
+                close(fd);
+        return -1;
 }
 

trunk/src/ifd/init.c

@@ -62 +62 @@
                 ct_config.debug = ival;
 
-        if (ifd_conf_get_string("ifdhandler", &sval) >= 0)
+        if (ifd_conf_get_string("ifdhandler.program", &sval) >= 0)
                 ct_config.ifdhandler = sval;
 

trunk/src/ifd/utils.c

@@ -14 +14 @@
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include <sys/types.h>
+#include <pwd.h>
+#include <grp.h>
 
 #ifndef __GNUC__
@@ -87 +90 @@
         int argc, n;
         pid_t pid;
+        char *user = NULL;
 
         ifd_debug(1, "driver=%s, devtype=%s, index=%d", driver, devtype, idx);
@@ -141 +145 @@
         while (--n > 2)
                 close(n);
+        
+        if ((n = ifd_conf_get_string_list("ifdhandler.groups", NULL, 0)) > 0) {
+                char **groups = (char **)calloc(n, sizeof(char *));
+                gid_t *gids = (gid_t *)calloc(n, sizeof(gid_t));
+                int j;
+                if (!groups || !gids) {
+                        ct_error("out of memory");
+                        exit(1);
+                }
+                n = ifd_conf_get_string_list("ifdhandler.groups", groups, n);
+                for (j = 0; j < n; j++) {
+                        struct group *g = getgrnam(groups[j]);
+                        if (g == NULL) {
+                                ct_error("failed to parse group %s", groups[j]);
+                                exit(1);
+                        }
+                        gids[j] = g->gr_gid;
+                }
+                if (setgroups(n-1, &gids[1]) == -1) {
+                        ct_error("failed set groups %m");
+                        exit(1);
+                }
+                if (setgid(gids[0]) == -1) {
+                        ct_error("failed setgid %d %m", gids[0]);
+                        exit(1);
+                }
+                free(groups);
+                free(gids);
+        }
+
+        if (ifd_conf_get_string("ifdhandler.user", &user) >= 0) {
+                struct passwd *p = getpwnam(user);
+
+                if (p == NULL) {
+                        ct_error("failed to parse user %s", user);
+                        exit(1);
+                }
+
+                if (setuid(p->pw_uid) == -1) {
+                        ct_error("failed to set*uid user %s %m", user);
+                        exit(1);
+                }
+        }
 
         execv(ct_config.ifdhandler, (char **)argv);

trunk/src/include/openct/openct.h

@@ -92 +92 @@
                                 const void *send_buf, size_t send_len);
 
-extern int              ct_status_clear(unsigned int);
+extern int              ct_status_clear(unsigned int, const char *);
 extern ct_info_t *      ct_status_alloc_slot(int *);
 extern int              ct_status_update(ct_info_t *);

trunk/src/tools/openct-control.c

@@ -94 +94 @@
 static int mgr_init(int argc, char **argv)
 {
+        char *ifdhandler_user = NULL;
+        char *sval;
         int n;
 
@@ -99 +101 @@
                 usage(1);
 
+        /* Get the ifdhandler user so we can set ownership */
+        if (ifd_conf_get_string("ifdhandler.user", &sval) >= 0)
+                ifdhandler_user = sval;
+
         /* Zap the status file */
-        ct_status_clear(OPENCT_MAX_READERS);
+        ct_status_clear(OPENCT_MAX_READERS, ifdhandler_user);
 
         /* Initialize IFD library */