1 files changed, 266 insertions, 0 deletions

diff --git a/other/openssh-2.1.1p4/auth-rhosts.c b/other/openssh-2.1.1p4/auth-rhosts.c
new file mode 100644
index 0000000..f670276
--- /dev/null
+++ b/other/openssh-2.1.1p4/auth-rhosts.c
@@ -0,0 +1,266 @@
+/*
+ *
+ * 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("$OpenBSD: auth-rhosts.c,v 1.14 2000/06/20 01:39:38 markus Exp $");
+
+#include "packet.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.
+ */
+
+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("/etc/hosts.equiv", &st) < 0 &&
+            stat(SSH_HOSTS_EQUIV, &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("/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 %.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 (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;
+}