- markus@cvs.openbsd.org 2002/06/11 04:14:26

     [ssh.c sshconnect.c sshconnect.h]
     no longer use uidswap.[ch] from the ssh client
     run less code with euid==0 if ssh is installed setuid root
     just switch the euid, don't switch the complete set of groups
     (this is only needed by sshd). ok provos@

1 files changed, 16 insertions, 31 deletions

diff --git a/sshconnect.c b/sshconnect.c
index 651e3fcf4..3a93a4fbb 100644
--- a/sshconnect.c
+++ b/sshconnect.c
@@ -13,7 +13,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: sshconnect.c,v 1.123 2002/06/09 22:17:21 itojun Exp $");
+RCSID("$OpenBSD: sshconnect.c,v 1.124 2002/06/11 04:14:26 markus Exp $");
 
 #include <openssl/bn.h>
 
@@ -36,8 +36,11 @@ RCSID("$OpenBSD: sshconnect.c,v 1.123 2002/06/09 22:17:21 itojun Exp $");
 char *client_version_string = NULL;
 char *server_version_string = NULL;
 
+/* import */
 extern Options options;
 extern char *__progname;
+extern uid_t original_real_uid;
+extern uid_t original_effective_uid;
 
 #ifndef INET6_ADDRSTRLEN                /* for non IPv6 machines */
 #define INET6_ADDRSTRLEN 46
@@ -58,8 +61,7 @@ sockaddr_ntop(struct sockaddr *sa, socklen_t salen)
  * Connect to the given ssh server using a proxy command.
  */
 static int
-ssh_proxy_connect(const char *host, u_short port, struct passwd *pw,
-                  const char *proxy_command)
+ssh_proxy_connect(const char *host, u_short port, const char *proxy_command)
 {
         Buffer command;
         const char *cp;
@@ -109,7 +111,8 @@ ssh_proxy_connect(const char *host, u_short port, struct passwd *pw,
                 char *argv[10];
 
                 /* Child.  Permanently give up superuser privileges. */
-                permanently_set_uid(pw);
+                seteuid(original_real_uid);
+                setuid(original_real_uid);
 
                 /* Redirect stdin and stdout. */
                 close(pin[1]);
@@ -159,7 +162,7 @@ ssh_proxy_connect(const char *host, u_short port, struct passwd *pw,
  * Creates a (possibly privileged) socket for use as the ssh connection.
  */
 static int
-ssh_create_socket(struct passwd *pw, int privileged, int family)
+ssh_create_socket(int privileged, int family)
 {
         int sock, gaierr;
         struct addrinfo hints, *res;
@@ -170,22 +173,18 @@ ssh_create_socket(struct passwd *pw, int privileged, int family)
          */
         if (privileged) {
                 int p = IPPORT_RESERVED - 1;
+                PRIV_START;
                 sock = rresvport_af(&p, family);
+                PRIV_END;
                 if (sock < 0)
                         error("rresvport: af=%d %.100s", family, strerror(errno));
                 else
                         debug("Allocated local port %d.", p);
                 return sock;
         }
-        /*
-         * Just create an ordinary socket on arbitrary port.  We use
-         * the user's uid to create the socket.
-         */
-        temporarily_use_uid(pw);
         sock = socket(family, SOCK_STREAM, 0);
         if (sock < 0)
                 error("socket: %.100s", strerror(errno));
-        restore_uid();
 
         /* Bind the socket to an alternative local IP address */
         if (options.bind_address == NULL)
@@ -215,9 +214,9 @@ ssh_create_socket(struct passwd *pw, int privileged, int family)
 /*
  * Opens a TCP/IP connection to the remote server on the given host.
  * The address of the remote host will be returned in hostaddr.
- * If port is 0, the default port will be used.  If anonymous is zero,
+ * If port is 0, the default port will be used.  If needpriv is true,
  * a privileged port will be allocated to make the connection.
- * This requires super-user privileges if anonymous is false.
+ * This requires super-user privileges if needpriv is true.
  * Connection_attempts specifies the maximum number of tries (one per
  * second).  If proxy_command is non-NULL, it specifies the command (with %h
  * and %p substituted for host and port, respectively) to use to contact
@@ -232,7 +231,7 @@ ssh_create_socket(struct passwd *pw, int privileged, int family)
 int
 ssh_connect(const char *host, struct sockaddr_storage * hostaddr,
     u_short port, int family, int connection_attempts,
-    int anonymous, struct passwd *pw, const char *proxy_command)
+    int needpriv, const char *proxy_command)
 {
         int gaierr;
         int on = 1;
@@ -248,8 +247,7 @@ ssh_connect(const char *host, struct sockaddr_storage * hostaddr,
          */
         int full_failure = 1;
 
-        debug("ssh_connect: getuid %u geteuid %u anon %d",
-            (u_int) getuid(), (u_int) geteuid(), anonymous);
+        debug("ssh_connect: needpriv %d", needpriv);
 
         /* Get default port if port has not been set. */
         if (port == 0) {
@@ -261,7 +259,7 @@ ssh_connect(const char *host, struct sockaddr_storage * hostaddr,
         }
         /* If a proxy command is given, connect using it. */
         if (proxy_command != NULL)
-                return ssh_proxy_connect(host, port, pw, proxy_command);
+                return ssh_proxy_connect(host, port, proxy_command);
 
         /* No proxy command. */
 
@@ -297,26 +295,14 @@ ssh_connect(const char *host, struct sockaddr_storage * hostaddr,
                                 host, ntop, strport);
 
                         /* Create a socket for connecting. */
-                        sock = ssh_create_socket(pw,
-#ifdef HAVE_CYGWIN
-                            !anonymous,
-#else
-                            !anonymous && geteuid() == 0,
-#endif
-                            ai->ai_family);
+                        sock = ssh_create_socket(needpriv, ai->ai_family);
                         if (sock < 0)
                                 /* Any error is already output */
                                 continue;
 
-                        /* Connect to the host.  We use the user's uid in the
-                         * hope that it will help with tcp_wrappers showing
-                         * the remote uid as root.
-                         */
-                        temporarily_use_uid(pw);
                         if (connect(sock, ai->ai_addr, ai->ai_addrlen) >= 0) {
                                 /* Successful connection. */
                                 memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen);
-                                restore_uid();
                                 break;
                         } else {
                                 if (errno == ECONNREFUSED)
@@ -324,7 +310,6 @@ ssh_connect(const char *host, struct sockaddr_storage * hostaddr,
                                 log("ssh: connect to address %s port %s: %s",
                                     sockaddr_ntop(ai->ai_addr, ai->ai_addrlen),
                                     strport, strerror(errno));
-                                restore_uid();
                                 /*
                                  * Close the failed socket; there appear to
                                  * be some problems when reusing a socket for