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[src/netbsd-1-5]: src/crypto/dist/ssh pull up rev 1.2 (approved by thorpej):



details:   https://anonhg.NetBSD.org/src/rev/4221b5ab170e
branches:  netbsd-1-5
changeset: 489660:4221b5ab170e
user:      lukem <lukem%NetBSD.org@localhost>
date:      Tue Oct 03 21:55:26 2000 +0000

description:
pull up rev 1.2 (approved by thorpej):
        - implement IgnoreRootRhosts

diffstat:

 crypto/dist/ssh/auth-rhosts.c |  274 +++++++++++
 crypto/dist/ssh/servconf.c    |  706 +++++++++++++++++++++++++++++
 crypto/dist/ssh/servconf.h    |  126 +++++
 crypto/dist/ssh/sshd.8        |  999 ++++++++++++++++++++++++++++++++++++++++++
 crypto/dist/ssh/sshd.conf     |   57 ++
 crypto/dist/ssh/version.h     |    3 +
 6 files changed, 2165 insertions(+), 0 deletions(-)

diffs (truncated from 2189 to 300 lines):

diff -r 5791e1d8f942 -r 4221b5ab170e crypto/dist/ssh/auth-rhosts.c
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/crypto/dist/ssh/auth-rhosts.c     Tue Oct 03 21:55:26 2000 +0000
@@ -0,0 +1,274 @@
+/*     $NetBSD: auth-rhosts.c,v 1.1.1.1.2.2 2000/10/03 21:55:26 lukem Exp $    */
+
+/*
+ * Author: Tatu Ylonen <ylo%cs.hut.fi@localhost>
+ * Copyright (c) 1995 Tatu Ylonen <ylo%cs.hut.fi@localhost>, Espoo, Finland
+ *                    All rights reserved
+ * Rhosts authentication.  This file contains code to check whether to admit
+ * the login based on rhosts authentication.  This file also processes
+ * /etc/hosts.equiv.
+ *
+ * As far as I am concerned, the code I have written for this software
+ * can be used freely for any purpose.  Any derived versions of this
+ * software must be clearly marked as such, and if the derived work is
+ * incompatible with the protocol description in the RFC file, it must be
+ * called by a name other than "ssh" or "Secure Shell".
+ */
+
+/* from OpenBSD: auth-rhosts.c,v 1.15 2000/09/07 20:27:49 deraadt Exp */
+
+#include <sys/cdefs.h>
+#ifndef lint
+__RCSID("$NetBSD: auth-rhosts.c,v 1.1.1.1.2.2 2000/10/03 21:55:26 lukem Exp $");
+#endif
+
+#include "includes.h"
+
+#include "packet.h"
+#include "pathnames.h"
+#include "ssh.h"
+#include "xmalloc.h"
+#include "uidswap.h"
+#include "servconf.h"
+
+/*
+ * This function processes an rhosts-style file (.rhosts, .shosts, or
+ * /etc/hosts.equiv).  This returns true if authentication can be granted
+ * based on the file, and returns zero otherwise.
+ */
+
+static 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, deny if unreadable */
+       f = fopen(filename, "r");
+       if (!f)
+               return 0;
+
+       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;
+       }
+
+       /* Authentication using this file denied. */
+       fclose(f);
+       return 0;
+}
+
+/*
+ * 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)
+{
+       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;
+
+       /* Switch to the user's uid. */
+       temporarily_use_uid(pw->pw_uid);
+       /*
+        * Quick check: if the user has no .shosts or .rhosts files, return
+        * failure immediately without doing costly lookups from name
+        * servers.
+        */
+       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();
+
+       /* Deny if The user has no .shosts or .rhosts file and there are no system-wide files. */
+       if (!rhosts_files[rhosts_file_index] &&
+           stat(_PATH_HEQUIV, &st) < 0 &&
+           stat(_PATH_SSH_HEQUIV, &st) < 0)
+               return 0;
+
+       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(_PATH_HEQUIV, hostname, ipaddr, client_user,
+                                     pw->pw_name)) {
+                       packet_send_debug("Accepted for %.100s [%.100s] by " _PATH_HEQUIV ".",
+                                         hostname, ipaddr);
+                       return 1;
+               }
+               if (check_rhosts_file(_PATH_SSH_HEQUIV, hostname, ipaddr, client_user,
+                                     pw->pw_name)) {
+                       packet_send_debug("Accepted for %.100s [%.100s] by %.100s.",
+                                     hostname, ipaddr, _PATH_SSH_HEQUIV);
+                       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 %.100s: 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;
+       }
+       /* 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 ((pw->pw_uid == 0 && options.ignore_root_rhosts) ||
+                   (pw->pw_uid != 0 && 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;
+               }
+       }
+
+       /* Restore the privileged uid. */
+       restore_uid();
+       return 0;
+}
diff -r 5791e1d8f942 -r 4221b5ab170e crypto/dist/ssh/servconf.c
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/crypto/dist/ssh/servconf.c        Tue Oct 03 21:55:26 2000 +0000
@@ -0,0 +1,706 @@
+/*     $NetBSD: servconf.c,v 1.1.1.1.2.2 2000/10/03 21:55:26 lukem Exp $       */
+
+/*
+ * Copyright (c) 1995 Tatu Ylonen <ylo%cs.hut.fi@localhost>, Espoo, Finland
+ *                    All rights reserved
+ *
+ * As far as I am concerned, the code I have written for this software
+ * can be used freely for any purpose.  Any derived versions of this
+ * software must be clearly marked as such, and if the derived work is
+ * incompatible with the protocol description in the RFC file, it must be
+ * called by a name other than "ssh" or "Secure Shell".
+ */
+
+/* from OpenBSD: servconf.c,v 1.51 2000/09/07 20:27:53 deraadt Exp */
+
+#include <sys/cdefs.h>
+#ifndef lint
+__RCSID("$NetBSD: servconf.c,v 1.1.1.1.2.2 2000/10/03 21:55:26 lukem Exp $");



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