/*
- * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
- * All rights reserved
- * Copyright (c) 2000 Markus Friedl. All rights reserved.
+ * Copyright (c) 2000 Markus Friedl. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "includes.h"
-RCSID("$OpenBSD: auth.c,v 1.7 2000/05/17 21:37:24 deraadt Exp $");
+RCSID("$OpenBSD: auth.c,v 1.25 2001/06/25 17:54:48 provos Exp $");
-#include "xmalloc.h"
-#include "rsa.h"
-#include "ssh.h"
-#include "pty.h"
-#include "packet.h"
-#include "buffer.h"
-#include "cipher.h"
-#include "mpaux.h"
-#include "servconf.h"
-#include "compat.h"
-#include "channels.h"
-#include "match.h"
#ifdef HAVE_LOGIN_H
#include <login.h>
#endif
+#if defined(HAVE_SHADOW_H) && !defined(DISABLE_SHADOW)
+#include <shadow.h>
+#endif /* defined(HAVE_SHADOW_H) && !defined(DISABLE_SHADOW) */
-#include "bufaux.h"
-#include "ssh2.h"
-#include "auth.h"
-#include "session.h"
-#include "dispatch.h"
+#ifdef HAVE_LIBGEN_H
+#include <libgen.h>
+#endif
+#include "xmalloc.h"
+#include "match.h"
+#include "groupaccess.h"
+#include "log.h"
+#include "servconf.h"
+#include "auth.h"
+#include "auth-options.h"
+#include "canohost.h"
+#include "buffer.h"
+#include "bufaux.h"
+#include "uidswap.h"
+#include "tildexpand.h"
/* import */
extern ServerOptions options;
-extern char *forced_command;
/*
- * Check if the user is allowed to log in via ssh. If user is listed in
- * DenyUsers or user's primary group is listed in DenyGroups, false will
- * be returned. If AllowUsers isn't empty and user isn't listed there, or
- * if AllowGroups isn't empty and user isn't listed there, false will be
- * returned.
+ * Check if the user is allowed to log in via ssh. If user is listed
+ * in DenyUsers or one of user's groups is listed in DenyGroups, false
+ * will be returned. If AllowUsers isn't empty and user isn't listed
+ * there, or if AllowGroups isn't empty and one of user's groups isn't
+ * listed there, false will be returned.
* If the user's shell is not executable, false will be returned.
* Otherwise true is returned.
*/
allowed_user(struct passwd * pw)
{
struct stat st;
- struct group *grp;
char *shell;
int i;
#ifdef WITH_AIXAUTHENTICATE
char *loginmsg;
#endif /* WITH_AIXAUTHENTICATE */
+#if !defined(USE_PAM) && defined(HAVE_SHADOW_H) && \
+ !defined(DISABLE_SHADOW) && defined(HAS_SHADOW_EXPIRE)
+ struct spwd *spw;
/* Shouldn't be called if pw is NULL, but better safe than sorry... */
- if (!pw)
+ if (!pw || !pw->pw_name)
return 0;
+ spw = getspnam(pw->pw_name);
+ if (spw != NULL) {
+ int days = time(NULL) / 86400;
+
+ /* Check account expiry */
+ if ((spw->sp_expire >= 0) && (days > spw->sp_expire))
+ return 0;
+
+ /* Check password expiry */
+ if ((spw->sp_lstchg >= 0) && (spw->sp_max >= 0) &&
+ (days > (spw->sp_lstchg + spw->sp_max)))
+ return 0;
+ }
+#else
+ /* Shouldn't be called if pw is NULL, but better safe than sorry... */
+ if (!pw || !pw->pw_name)
+ return 0;
+#endif
+
/*
* Get the shell from the password data. An empty shell field is
* legal, and means /bin/sh.
/* Return false if user is listed in DenyUsers */
if (options.num_deny_users > 0) {
- if (!pw->pw_name)
- return 0;
for (i = 0; i < options.num_deny_users; i++)
if (match_pattern(pw->pw_name, options.deny_users[i]))
return 0;
}
/* Return false if AllowUsers isn't empty and user isn't listed there */
if (options.num_allow_users > 0) {
- if (!pw->pw_name)
- return 0;
for (i = 0; i < options.num_allow_users; i++)
if (match_pattern(pw->pw_name, options.allow_users[i]))
break;
if (i >= options.num_allow_users)
return 0;
}
- /* Get the primary group name if we need it. Return false if it fails */
if (options.num_deny_groups > 0 || options.num_allow_groups > 0) {
- grp = getgrgid(pw->pw_gid);
- if (!grp)
+ /* Get the user's group access list (primary and supplementary) */
+ if (ga_init(pw->pw_name, pw->pw_gid) == 0)
return 0;
- /* Return false if user's group is listed in DenyGroups */
- if (options.num_deny_groups > 0) {
- if (!grp->gr_name)
+ /* Return false if one of user's groups is listed in DenyGroups */
+ if (options.num_deny_groups > 0)
+ if (ga_match(options.deny_groups,
+ options.num_deny_groups)) {
+ ga_free();
return 0;
- for (i = 0; i < options.num_deny_groups; i++)
- if (match_pattern(grp->gr_name, options.deny_groups[i]))
- return 0;
- }
+ }
/*
- * Return false if AllowGroups isn't empty and user's group
+ * Return false if AllowGroups isn't empty and one of user's groups
* isn't listed there
*/
- if (options.num_allow_groups > 0) {
- if (!grp->gr_name)
+ if (options.num_allow_groups > 0)
+ if (!ga_match(options.allow_groups,
+ options.num_allow_groups)) {
+ ga_free();
return 0;
- for (i = 0; i < options.num_allow_groups; i++)
- if (match_pattern(grp->gr_name, options.allow_groups[i]))
- break;
- /* i < options.num_allow_groups iff we break for
- loop */
- if (i >= options.num_allow_groups)
- return 0;
- }
+ }
+ ga_free();
}
#ifdef WITH_AIXAUTHENTICATE
/* We found no reason not to let this user try to log on... */
return 1;
}
+
+Authctxt *
+authctxt_new(void)
+{
+ Authctxt *authctxt = xmalloc(sizeof(*authctxt));
+ memset(authctxt, 0, sizeof(*authctxt));
+ return authctxt;
+}
+
+void
+auth_log(Authctxt *authctxt, int authenticated, char *method, char *info)
+{
+ void (*authlog) (const char *fmt,...) = verbose;
+ char *authmsg;
+
+ /* Raise logging level */
+ if (authenticated == 1 ||
+ !authctxt->valid ||
+ authctxt->failures >= AUTH_FAIL_LOG ||
+ strcmp(method, "password") == 0)
+ authlog = log;
+
+ if (authctxt->postponed)
+ authmsg = "Postponed";
+ else
+ authmsg = authenticated ? "Accepted" : "Failed";
+
+ authlog("%s %s for %s%.100s from %.200s port %d%s",
+ authmsg,
+ method,
+ authctxt->valid ? "" : "illegal user ",
+ authctxt->valid && authctxt->pw->pw_uid == 0 ? "ROOT" : authctxt->user,
+ get_remote_ipaddr(),
+ get_remote_port(),
+ info);
+}
+
+/*
+ * Check whether root logins are disallowed.
+ */
+int
+auth_root_allowed(char *method)
+{
+ switch (options.permit_root_login) {
+ case PERMIT_YES:
+ return 1;
+ break;
+ case PERMIT_NO_PASSWD:
+ if (strcmp(method, "password") != 0)
+ return 1;
+ break;
+ case PERMIT_FORCED_ONLY:
+ if (forced_command) {
+ log("Root login accepted for forced command.");
+ return 1;
+ }
+ break;
+ }
+ log("ROOT LOGIN REFUSED FROM %.200s", get_remote_ipaddr());
+ return 0;
+}
+
+
+/*
+ * Given a template and a passwd structure, build a filename
+ * by substituting % tokenised options. Currently, %% becomes '%',
+ * %h becomes the home directory and %u the username.
+ *
+ * This returns a buffer allocated by xmalloc.
+ */
+char *
+expand_filename(const char *filename, struct passwd *pw)
+{
+ Buffer buffer;
+ char *file;
+ const char *cp;
+
+ /*
+ * Build the filename string in the buffer by making the appropriate
+ * substitutions to the given file name.
+ */
+ buffer_init(&buffer);
+ for (cp = filename; *cp; cp++) {
+ if (cp[0] == '%' && cp[1] == '%') {
+ buffer_append(&buffer, "%", 1);
+ cp++;
+ continue;
+ }
+ if (cp[0] == '%' && cp[1] == 'h') {
+ buffer_append(&buffer, pw->pw_dir, strlen(pw->pw_dir));
+ cp++;
+ continue;
+ }
+ if (cp[0] == '%' && cp[1] == 'u') {
+ buffer_append(&buffer, pw->pw_name,
+ strlen(pw->pw_name));
+ cp++;
+ continue;
+ }
+ buffer_append(&buffer, cp, 1);
+ }
+ buffer_append(&buffer, "\0", 1);
+
+ /*
+ * Ensure that filename starts anchored. If not, be backward
+ * compatible and prepend the '%h/'
+ */
+ file = xmalloc(MAXPATHLEN);
+ cp = buffer_ptr(&buffer);
+ if (*cp != '/')
+ snprintf(file, MAXPATHLEN, "%s/%s", pw->pw_dir, cp);
+ else
+ strlcpy(file, cp, MAXPATHLEN);
+
+ buffer_free(&buffer);
+ return file;
+}
+
+char *
+authorized_keys_file(struct passwd *pw)
+{
+ return expand_filename(options.authorized_keys_file, pw);
+}
+
+char *
+authorized_keys_file2(struct passwd *pw)
+{
+ return expand_filename(options.authorized_keys_file2, pw);
+}
+
+/* return ok if key exists in sysfile or userfile */
+HostStatus
+check_key_in_hostfiles(struct passwd *pw, Key *key, const char *host,
+ const char *sysfile, const char *userfile)
+{
+ Key *found;
+ char *user_hostfile;
+ struct stat st;
+ int host_status;
+
+ /* Check if we know the host and its host key. */
+ found = key_new(key->type);
+ host_status = check_host_in_hostfile(sysfile, host, key, found, NULL);
+
+ if (host_status != HOST_OK && userfile != NULL) {
+ user_hostfile = tilde_expand_filename(userfile, pw->pw_uid);
+ if (options.strict_modes &&
+ (stat(user_hostfile, &st) == 0) &&
+ ((st.st_uid != 0 && st.st_uid != pw->pw_uid) ||
+ (st.st_mode & 022) != 0)) {
+ log("Authentication refused for %.100s: "
+ "bad owner or modes for %.200s",
+ pw->pw_name, user_hostfile);
+ } else {
+ temporarily_use_uid(pw);
+ host_status = check_host_in_hostfile(user_hostfile,
+ host, key, found, NULL);
+ restore_uid();
+ }
+ xfree(user_hostfile);
+ }
+ key_free(found);
+
+ debug2("check_key_in_hostfiles: key %s for %s", host_status == HOST_OK ?
+ "ok" : "not found", host);
+ return host_status;
+}
+
+
+/*
+ * Check a given file for security. This is defined as all components
+ * of the path to the file must either be owned by either the owner of
+ * of the file or root and no directories must be group or world writable.
+ *
+ * XXX Should any specific check be done for sym links ?
+ *
+ * Takes an open file descriptor, the file name, a uid and and
+ * error buffer plus max size as arguments.
+ *
+ * Returns 0 on success and -1 on failure
+ */
+int
+secure_filename(FILE *f, const char *file, struct passwd *pw,
+ char *err, size_t errlen)
+{
+ uid_t uid = pw->pw_uid;
+ char homedir[MAXPATHLEN];
+ char buf[MAXPATHLEN];
+ char *cp;
+ struct stat st;
+
+ strlcpy(homedir, dirname(pw->pw_dir), sizeof(homedir));
+
+ if (realpath(file, buf) == NULL) {
+ snprintf(err, errlen, "realpath %s failed: %s", file,
+ strerror(errno));
+ return -1;
+ }
+
+ /* check the open file to avoid races */
+ if (fstat(fileno(f), &st) < 0 ||
+ (st.st_uid != 0 && st.st_uid != uid) ||
+ (st.st_mode & 022) != 0) {
+ snprintf(err, errlen, "bad ownership or modes for file %s",
+ buf);
+ return -1;
+ }
+
+ debug3("secure_filename: terminating check at '%s'", homedir);
+
+ /* for each component of the canonical path, walking upwards */
+ for (;;) {
+ if ((cp = dirname(buf)) == NULL) {
+ snprintf(err, errlen, "dirname() failed");
+ return -1;
+ }
+ strlcpy(buf, cp, sizeof(buf));
+
+ /* If are passed the homedir then we can stop */
+ if (strcmp(buf, homedir) == 0)
+ break;
+
+ debug3("secure_filename: checking '%s'", buf);
+ if (stat(buf, &st) < 0 ||
+ (st.st_uid != 0 && st.st_uid != uid) ||
+ (st.st_mode & 022) != 0) {
+ snprintf(err, errlen,
+ "bad ownership or modes for directory %s", buf);
+ return -1;
+ }
+
+ /*
+ * dirname should always complete with a "/" path,
+ * but we can be paranoid and check for "." too
+ */
+ if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0))
+ break;
+ }
+ return 0;
+}
andersk / openssh.git / blobdiff