1 files changed, 224 insertions, 252 deletions

diff --git a/auth-rhosts.c b/auth-rhosts.c
index dc82849be..500dcebb1 100644
--- a/auth-rhosts.c
+++ b/auth-rhosts.c
@@ -1,22 +1,22 @@
 /*
-
-auth-rhosts.c
-
-Author: Tatu Ylonen <ylo@cs.hut.fi>
-
-Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
-                   All rights reserved
-
-Created: Fri Mar 17 05:12:18 1995 ylo
-
-Rhosts authentication.  This file contains code to check whether to admit
-the login based on rhosts authentication.  This file also processes
-/etc/hosts.equiv.
-
-*/
+ * 
+ * auth-rhosts.c
+ * 
+ * Author: Tatu Ylonen <ylo@cs.hut.fi>
+ * 
+ * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
+ *                    All rights reserved
+ * 
+ * Created: Fri Mar 17 05:12:18 1995 ylo
+ * 
+ * Rhosts authentication.  This file contains code to check whether to admit
+ * the login based on rhosts authentication.  This file also processes
+ * /etc/hosts.equiv.
+ * 
+ */
 
 #include "includes.h"
-RCSID("$Id: auth-rhosts.c,v 1.4 1999/11/18 21:25:48 damien Exp $");
+RCSID("$Id: auth-rhosts.c,v 1.5 1999/11/24 13:26:21 damien Exp $");
 
 #include "packet.h"
 #include "ssh.h"
@@ -28,256 +28,228 @@ RCSID("$Id: auth-rhosts.c,v 1.4 1999/11/18 21:25:48 damien Exp $");
    /etc/hosts.equiv).  This returns true if authentication can be granted
    based on the file, and returns zero otherwise. */
 
-int check_rhosts_file(const char *filename, const char *hostname,
-                      const char *ipaddr, const char *client_user,
-                      const char *server_user)
+int 
+check_rhosts_file(const char *filename, const char *hostname,
+                  const char *ipaddr, const char *client_user,
+                  const char *server_user)
 {
-  FILE *f;
-  char buf[1024]; /* Must not be larger than host, user, dummy below. */
-  
-  /* Open the .rhosts file. */
-  f = fopen(filename, "r");
-  if (!f)
-    return 0; /* Cannot read the .rhosts - deny access. */
-
-  /* Go through the file, checking every entry. */
-  while (fgets(buf, sizeof(buf), f))
-    {
-      /* All three must be at least as big as buf to avoid overflows. */
-      char hostbuf[1024], userbuf[1024], dummy[1024], *host, *user, *cp;
-      int negated;
-      
-      for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
-        ;
-      if (*cp == '#' || *cp == '\n' || !*cp)
-        continue;
-
-      /* NO_PLUS is supported at least on OSF/1.  We skip it (we don't ever
-         support the plus syntax). */
-      if (strncmp(cp, "NO_PLUS", 7) == 0)
-        continue;
-
-      /* This should be safe because each buffer is as big as the whole
-         string, and thus cannot be overwritten. */
-      switch (sscanf(buf, "%s %s %s", hostbuf, userbuf, dummy))
-        {
-        case 0:
-          packet_send_debug("Found empty line in %.100s.", filename);
-          continue; /* Empty line? */
-        case 1:
-          /* Host name only. */
-          strlcpy(userbuf, server_user, sizeof(userbuf));
-          break;
-        case 2:
-          /* Got both host and user name. */
-          break;
-        case 3:
-          packet_send_debug("Found garbage in %.100s.", filename);
-          continue; /* Extra garbage */
-        default:
-          continue; /* Weird... */
-        }
-
-      host = hostbuf;
-      user = userbuf;
-      negated = 0;
-
-      /* Process negated host names, or positive netgroups. */
-      if (host[0] == '-')
-        {
-          negated = 1;
-          host++;
-        }
-      else
-        if (host[0] == '+')
-          host++;
-
-      if (user[0] == '-')
-        {
-          negated = 1;
-          user++;
-        }
-      else
-        if (user[0] == '+')
-          user++;
-
-      /* Check for empty host/user names (particularly '+'). */
-      if (!host[0] || !user[0])
-        { 
-          /* We come here if either was '+' or '-'. */
-          packet_send_debug("Ignoring wild host/user names in %.100s.",
-                            filename);
-          continue;
-        }
-          
-      /* Verify that host name matches. */
-      if (host[0] == '@')
-        {
-          if (!innetgr(host + 1, hostname, NULL, NULL) &&
-              !innetgr(host + 1, ipaddr, NULL, NULL))
-            continue;
-        }
-      else
-        if (strcasecmp(host, hostname) && strcmp(host, ipaddr) != 0)
-          continue; /* Different hostname. */
-
-      /* Verify that user name matches. */
-      if (user[0] == '@')
-        {
-          if (!innetgr(user + 1, NULL, client_user, NULL))
-            continue;
+        FILE *f;
+        char buf[1024]; /* Must not be larger than host, user, dummy below. */
+
+        /* Open the .rhosts file, deny if unreadable */
+        f = fopen(filename, "r");
+        if (!f)
+                return 0;
+
+        /* Go through the file, checking every entry. */
+        while (fgets(buf, sizeof(buf), f)) {
+                /* All three must be at least as big as buf to avoid overflows. */
+                char hostbuf[1024], userbuf[1024], dummy[1024], *host, *user, *cp;
+                int negated;
+
+                for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
+                        ;
+                if (*cp == '#' || *cp == '\n' || !*cp)
+                        continue;
+
+                /* NO_PLUS is supported at least on OSF/1.  We skip it (we
+                   don't ever support the plus syntax). */
+                if (strncmp(cp, "NO_PLUS", 7) == 0)
+                        continue;
+
+                /* This should be safe because each buffer is as big as
+                   the whole string, and thus cannot be overwritten. */
+                switch (sscanf(buf, "%s %s %s", hostbuf, userbuf, dummy)) {
+                case 0:
+                        packet_send_debug("Found empty line in %.100s.", filename);
+                        continue;
+                case 1:
+                        /* Host name only. */
+                        strlcpy(userbuf, server_user, sizeof(userbuf));
+                        break;
+                case 2:
+                        /* Got both host and user name. */
+                        break;
+                case 3:
+                        packet_send_debug("Found garbage in %.100s.", filename);
+                        continue;
+                default:
+                        /* Weird... */
+                        continue;
+                }
+
+                host = hostbuf;
+                user = userbuf;
+                negated = 0;
+
+                /* Process negated host names, or positive netgroups. */
+                if (host[0] == '-') {
+                        negated = 1;
+                        host++;
+                } else if (host[0] == '+')
+                        host++;
+
+                if (user[0] == '-') {
+                        negated = 1;
+                        user++;
+                } else if (user[0] == '+')
+                        user++;
+
+                /* Check for empty host/user names (particularly '+'). */
+                if (!host[0] || !user[0]) {
+                        /* We come here if either was '+' or '-'. */
+                        packet_send_debug("Ignoring wild host/user names in %.100s.",
+                                          filename);
+                        continue;
+                }
+                /* Verify that host name matches. */
+                if (host[0] == '@') {
+                        if (!innetgr(host + 1, hostname, NULL, NULL) &&
+                            !innetgr(host + 1, ipaddr, NULL, NULL))
+                                continue;
+                } else if (strcasecmp(host, hostname) && strcmp(host, ipaddr) != 0)
+                        continue;       /* Different hostname. */
+
+                /* Verify that user name matches. */
+                if (user[0] == '@') {
+                        if (!innetgr(user + 1, NULL, client_user, NULL))
+                                continue;
+                } else if (strcmp(user, client_user) != 0)
+                        continue;       /* Different username. */
+
+                /* Found the user and host. */
+                fclose(f);
+
+                /* If the entry was negated, deny access. */
+                if (negated) {
+                        packet_send_debug("Matched negative entry in %.100s.",
+                                          filename);
+                        return 0;
+                }
+                /* Accept authentication. */
+                return 1;
         }
-      else
-        if (strcmp(user, client_user) != 0)
-          continue; /* Different username. */
 
-      /* Found the user and host. */
-      fclose(f);
-
-      /* If the entry was negated, deny access. */
-      if (negated)
-        {
-          packet_send_debug("Matched negative entry in %.100s.",
-                            filename);
-          return 0;
-        }
-
-      /* Accept authentication. */
-      return 1;
-    }
-     
-  /* Authentication using this file denied. */
-  fclose(f);
-  return 0;
+        /* Authentication using this file denied. */
+        fclose(f);
+        return 0;
 }
 
-/* Tries to authenticate the user using the .shosts or .rhosts file.  
+/* Tries to authenticate the user using the .shosts or .rhosts file.
    Returns true if authentication succeeds.  If ignore_rhosts is
    true, only /etc/hosts.equiv will be considered (.rhosts and .shosts
    are ignored). */
 
-int auth_rhosts(struct passwd *pw, const char *client_user)
+int 
+auth_rhosts(struct passwd *pw, const char *client_user)
 {
-  extern ServerOptions options;
-  char buf[1024];
-  const char *hostname, *ipaddr;
-  struct stat st;
-  static const char *rhosts_files[] = { ".shosts", ".rhosts", NULL };
-  unsigned int rhosts_file_index;
-
-  /* Quick check: if the user has no .shosts or .rhosts files, return failure
-     immediately without doing costly lookups from name servers. */
-  /* Switch to the user's uid. */
-  temporarily_use_uid(pw->pw_uid);
-  for (rhosts_file_index = 0; rhosts_files[rhosts_file_index];
-       rhosts_file_index++)
-    {
-      /* Check users .rhosts or .shosts. */
-      snprintf(buf, sizeof buf, "%.500s/%.100s", 
-              pw->pw_dir, rhosts_files[rhosts_file_index]);
-      if (stat(buf, &st) >= 0)
-        break;
-    }
-  /* Switch back to privileged uid. */
-  restore_uid();
-
-  if (!rhosts_files[rhosts_file_index] && stat("/etc/hosts.equiv", &st) < 0 &&
-      stat(SSH_HOSTS_EQUIV, &st) < 0)
-    return 0; /* The user has no .shosts or .rhosts file and there are no
-                 system-wide files. */
-
-  /* Get the name, address, and port of the remote host.  */
-  hostname = get_canonical_hostname();
-  ipaddr = get_remote_ipaddr();
-
-  /* If not logging in as superuser, try /etc/hosts.equiv and shosts.equiv. */
-  if (pw->pw_uid != 0)
-    {
-      if (check_rhosts_file("/etc/hosts.equiv", hostname, ipaddr, client_user,
-                            pw->pw_name))
-        {
-          packet_send_debug("Accepted for %.100s [%.100s] by /etc/hosts.equiv.",
-                            hostname, ipaddr);
-          return 1;
+        extern ServerOptions options;
+        char buf[1024];
+        const char *hostname, *ipaddr;
+        struct stat st;
+        static const char *rhosts_files[] = {".shosts", ".rhosts", NULL};
+        unsigned int rhosts_file_index;
+
+        /* Quick check: if the user has no .shosts or .rhosts files,
+           return failure immediately without doing costly lookups from
+           name servers. */
+        /* Switch to the user's uid. */
+        temporarily_use_uid(pw->pw_uid);
+        for (rhosts_file_index = 0; rhosts_files[rhosts_file_index];
+             rhosts_file_index++) {
+                /* Check users .rhosts or .shosts. */
+                snprintf(buf, sizeof buf, "%.500s/%.100s",
+                         pw->pw_dir, rhosts_files[rhosts_file_index]);
+                if (stat(buf, &st) >= 0)
+                        break;
         }
-      if (check_rhosts_file(SSH_HOSTS_EQUIV, hostname, ipaddr, client_user,
-                            pw->pw_name))
-        {
-          packet_send_debug("Accepted for %.100s [%.100s] by %.100s.", 
-                            hostname, ipaddr, SSH_HOSTS_EQUIV);
-          return 1;
+        /* Switch back to privileged uid. */
+        restore_uid();
+
+        /* Deny if The user has no .shosts or .rhosts file and there are no system-wide files. */
+        if (!rhosts_files[rhosts_file_index] &&
+            stat("/etc/hosts.equiv", &st) < 0 &&
+            stat(SSH_HOSTS_EQUIV, &st) < 0)
+                return 0;
+
+        /* Get the name, address, and port of the remote host.  */
+        hostname = get_canonical_hostname();
+        ipaddr = get_remote_ipaddr();
+
+        /* If not logging in as superuser, try /etc/hosts.equiv and shosts.equiv. */
+        if (pw->pw_uid != 0) {
+                if (check_rhosts_file("/etc/hosts.equiv", hostname, ipaddr, client_user,
+                                      pw->pw_name)) {
+                        packet_send_debug("Accepted for %.100s [%.100s] by /etc/hosts.equiv.",
+                                          hostname, ipaddr);
+                        return 1;
+                }
+                if (check_rhosts_file(SSH_HOSTS_EQUIV, hostname, ipaddr, client_user,
+                                      pw->pw_name)) {
+                        packet_send_debug("Accepted for %.100s [%.100s] by %.100s.",
+                                      hostname, ipaddr, SSH_HOSTS_EQUIV);
+                        return 1;
+                }
         }
-    }
-
-  /* Check that the home directory is owned by root or the user, and is not 
-     group or world writable. */
-  if (stat(pw->pw_dir, &st) < 0)
-    {
-      log("Rhosts authentication refused for %.100s: no home directory %.200s",
-          pw->pw_name, pw->pw_dir);
-      packet_send_debug("Rhosts authentication refused for %.100: no home directory %.200s",
-                        pw->pw_name, pw->pw_dir);
-      return 0;
-    }
-  if (options.strict_modes && 
-      ((st.st_uid != 0 && st.st_uid != pw->pw_uid) ||
-       (st.st_mode & 022) != 0))
-    {
-      log("Rhosts authentication refused for %.100s: bad ownership or modes for home directory.",
-          pw->pw_name);
-      packet_send_debug("Rhosts authentication refused for %.100s: bad ownership or modes for home directory.",
-                        pw->pw_name);
-      return 0;
-    }
-  
-  /* Check all .rhosts files (currently .shosts and .rhosts). */
-  /* Temporarily use the user's uid. */
-  temporarily_use_uid(pw->pw_uid);
-  for (rhosts_file_index = 0; rhosts_files[rhosts_file_index];
-       rhosts_file_index++)
-    {
-      /* Check users .rhosts or .shosts. */
-      snprintf(buf, sizeof buf, "%.500s/%.100s", 
-              pw->pw_dir, rhosts_files[rhosts_file_index]);
-      if (stat(buf, &st) < 0)
-        continue; /* No such file. */
-
-      /* Make sure that the file is either owned by the user or by root,
-         and make sure it is not writable by anyone but the owner.  This is
-         to help avoid novices accidentally allowing access to their account
-         by anyone. */
-      if (options.strict_modes &&
-          ((st.st_uid != 0 && st.st_uid != pw->pw_uid) ||
-           (st.st_mode & 022) != 0))
-        {
-          log("Rhosts authentication refused for %.100s: bad modes for %.200s",
-              pw->pw_name, buf);
-          packet_send_debug("Bad file modes for %.200s", buf);
-          continue;
+        /* Check that the home directory is owned by root or the user, and
+           is not group or world writable. */
+        if (stat(pw->pw_dir, &st) < 0) {
+                log("Rhosts authentication refused for %.100s: no home directory %.200s",
+                    pw->pw_name, pw->pw_dir);
+                packet_send_debug("Rhosts authentication refused for %.100: no home directory %.200s",
+                                  pw->pw_name, pw->pw_dir);
+                return 0;
         }
-
-      /* Check if we have been configured to ignore .rhosts and .shosts 
-         files. */
-      if (options.ignore_rhosts)
-        {
-          packet_send_debug("Server has been configured to ignore %.100s.",
-                            rhosts_files[rhosts_file_index]);
-          continue;
+        if (options.strict_modes &&
+            ((st.st_uid != 0 && st.st_uid != pw->pw_uid) ||
+             (st.st_mode & 022) != 0)) {
+                log("Rhosts authentication refused for %.100s: bad ownership or modes for home directory.",
+                    pw->pw_name);
+                packet_send_debug("Rhosts authentication refused for %.100s: bad ownership or modes for home directory.",
+                                  pw->pw_name);
+                return 0;
         }
-
-      /* Check if authentication is permitted by the file. */
-      if (check_rhosts_file(buf, hostname, ipaddr, client_user, pw->pw_name))
-        {
-          packet_send_debug("Accepted by %.100s.",
-                            rhosts_files[rhosts_file_index]);
-          /* Restore the privileged uid. */
-          restore_uid();
-          return 1;
+        /* Temporarily use the user's uid. */
+        temporarily_use_uid(pw->pw_uid);
+
+        /* Check all .rhosts files (currently .shosts and .rhosts). */
+        for (rhosts_file_index = 0; rhosts_files[rhosts_file_index];
+             rhosts_file_index++) {
+                /* Check users .rhosts or .shosts. */
+                snprintf(buf, sizeof buf, "%.500s/%.100s",
+                         pw->pw_dir, rhosts_files[rhosts_file_index]);
+                if (stat(buf, &st) < 0)
+                        continue;
+
+                /* Make sure that the file is either owned by the user or
+                   by root, and make sure it is not writable by anyone but
+                   the owner.  This is to help avoid novices accidentally
+                   allowing access to their account by anyone. */
+                if (options.strict_modes &&
+                    ((st.st_uid != 0 && st.st_uid != pw->pw_uid) ||
+                     (st.st_mode & 022) != 0)) {
+                        log("Rhosts authentication refused for %.100s: bad modes for %.200s",
+                            pw->pw_name, buf);
+                        packet_send_debug("Bad file modes for %.200s", buf);
+                        continue;
+                }
+                /* Check if we have been configured to ignore .rhosts and .shosts files. */
+                if (options.ignore_rhosts) {
+                        packet_send_debug("Server has been configured to ignore %.100s.",
+                                          rhosts_files[rhosts_file_index]);
+                        continue;
+                }
+                /* Check if authentication is permitted by the file. */
+                if (check_rhosts_file(buf, hostname, ipaddr, client_user, pw->pw_name)) {
+                        packet_send_debug("Accepted by %.100s.",
+                                          rhosts_files[rhosts_file_index]);
+                        /* Restore the privileged uid. */
+                        restore_uid();
+                        return 1;
+                }
         }
-    }
 
-  /* Rhosts authentication denied. */
-  /* Restore the privileged uid. */
-  restore_uid();
-  return 0;
+        /* Restore the privileged uid. */
+        restore_uid();
+        return 0;
 }