- markus@cvs.openbsd.org 2002/06/10 22:28:41

     [channels.c channels.h session.c]
     move creation of agent socket to session.c; no need for uidswapping
     in channel.c.

1 files changed, 91 insertions, 4 deletions

diff --git a/session.c b/session.c
index dcecf1ae3..d2a460f89 100644
--- a/session.c
+++ b/session.c
@@ -33,7 +33,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: session.c,v 1.135 2002/05/16 22:09:59 stevesk Exp $");
+RCSID("$OpenBSD: session.c,v 1.136 2002/06/10 22:28:41 markus Exp $");
 
 #include "ssh.h"
 #include "ssh1.h"
@@ -111,6 +111,93 @@ char *aixloginmsg;
 login_cap_t *lc;
 #endif
 
+/* Name and directory of socket for authentication agent forwarding. */
+static char *auth_sock_name = NULL;
+static char *auth_sock_dir = NULL;
+
+/* removes the agent forwarding socket */
+
+static void
+auth_sock_cleanup_proc(void *_pw)
+{
+        struct passwd *pw = _pw;
+
+        if (auth_sock_name != NULL) {
+                temporarily_use_uid(pw);
+                unlink(auth_sock_name);
+                rmdir(auth_sock_dir);
+                auth_sock_name = NULL;
+                restore_uid();
+        }
+}
+
+static int
+auth_input_request_forwarding(struct passwd * pw)
+{
+        Channel *nc;
+        int sock;
+        struct sockaddr_un sunaddr;
+
+        if (auth_sock_name != NULL) {
+                error("authentication forwarding requested twice.");
+                return 0;
+        }
+
+        /* Temporarily drop privileged uid for mkdir/bind. */
+        temporarily_use_uid(pw);
+
+        /* Allocate a buffer for the socket name, and format the name. */
+        auth_sock_name = xmalloc(MAXPATHLEN);
+        auth_sock_dir = xmalloc(MAXPATHLEN);
+        strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
+
+        /* Create private directory for socket */
+        if (mkdtemp(auth_sock_dir) == NULL) {
+                packet_send_debug("Agent forwarding disabled: "
+                    "mkdtemp() failed: %.100s", strerror(errno));
+                restore_uid();
+                xfree(auth_sock_name);
+                xfree(auth_sock_dir);
+                auth_sock_name = NULL;
+                auth_sock_dir = NULL;
+                return 0;
+        }
+        snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%d",
+                 auth_sock_dir, (int) getpid());
+
+        /* delete agent socket on fatal() */
+        fatal_add_cleanup(auth_sock_cleanup_proc, pw);
+
+        /* Create the socket. */
+        sock = socket(AF_UNIX, SOCK_STREAM, 0);
+        if (sock < 0)
+                packet_disconnect("socket: %.100s", strerror(errno));
+
+        /* Bind it to the name. */
+        memset(&sunaddr, 0, sizeof(sunaddr));
+        sunaddr.sun_family = AF_UNIX;
+        strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
+
+        if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
+                packet_disconnect("bind: %.100s", strerror(errno));
+
+        /* Restore the privileged uid. */
+        restore_uid();
+
+        /* Start listening on the socket. */
+        if (listen(sock, 5) < 0)
+                packet_disconnect("listen: %.100s", strerror(errno));
+
+        /* Allocate a channel for the authentication agent socket. */
+        nc = channel_new("auth socket",
+            SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
+            CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
+            0, xstrdup("auth socket"), 1);
+        strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
+        return 1;
+}
+
+
 void
 do_authenticated(Authctxt *authctxt)
 {
@@ -141,7 +228,7 @@ do_authenticated(Authctxt *authctxt)
                 do_authenticated1(authctxt);
 
         /* remove agent socket */
-        if (auth_get_socket_name())
+        if (auth_sock_name != NULL)
                 auth_sock_cleanup_proc(authctxt->pw);
 #ifdef KRB4
         if (options.kerberos_ticket_cleanup)
@@ -948,9 +1035,9 @@ do_setup_env(Session *s, const char *shell)
         copy_environment(fetch_pam_environment(), &env, &envsize);
 #endif /* USE_PAM */
 
-        if (auth_get_socket_name() != NULL)
+        if (auth_sock_name != NULL)
                 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
-                    auth_get_socket_name());
+                    auth_sock_name);
 
         /* read $HOME/.ssh/environment. */
         if (!options.use_login) {