2 * Copyright (c) 1997 - 2005 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the Institute nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
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23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
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34 #include "krb5_locl.h"
39 /* see if principal is mentioned in the filename access file, return
40 TRUE (in result) if so, FALSE otherwise */
42 static krb5_error_code
43 check_one_file(krb5_context context,
46 krb5_principal principal,
56 f = fopen (filename, "r");
61 /* check type and mode of file */
62 if (fstat(fileno(f), &st) != 0) {
66 if (S_ISDIR(st.st_mode)) {
70 if (st.st_uid != pwd->pw_uid && st.st_uid != 0) {
74 if ((st.st_mode & (S_IWGRP | S_IWOTH)) != 0) {
79 while (fgets (buf, sizeof(buf), f) != NULL) {
81 char *newline = buf + strcspn(buf, "\n");
83 if(*newline != '\n') {
87 while(c != EOF && c != '\n')
89 /* line was too long, so ignore it */
94 ret = krb5_parse_name (context, buf, &tmp);
97 *result = krb5_principal_compare (context, principal, tmp);
98 krb5_free_principal (context, tmp);
108 static krb5_error_code
109 check_directory(krb5_context context,
112 krb5_principal principal,
113 krb5_boolean *result)
117 char filename[MAXPATHLEN];
118 krb5_error_code ret = 0;
123 if(lstat(dirname, &st) < 0)
126 if (!S_ISDIR(st.st_mode))
129 if (st.st_uid != pwd->pw_uid && st.st_uid != 0)
131 if ((st.st_mode & (S_IWGRP | S_IWOTH)) != 0)
134 if((d = opendir(dirname)) == NULL)
142 if(fstat(fd, &st2) < 0) {
146 if(st.st_dev != st2.st_dev || st.st_ino != st2.st_ino) {
152 while((dent = readdir(d)) != NULL) {
153 if(strcmp(dent->d_name, ".") == 0 ||
154 strcmp(dent->d_name, "..") == 0 ||
155 dent->d_name[0] == '#' || /* emacs autosave */
156 dent->d_name[strlen(dent->d_name) - 1] == '~') /* emacs backup */
158 snprintf(filename, sizeof(filename), "%s/%s", dirname, dent->d_name);
159 ret = check_one_file(context, filename, pwd, principal, result);
160 if(ret == 0 && *result == TRUE)
162 ret = 0; /* don't propagate errors upstream */
171 match_local_principals(krb5_context context,
172 krb5_principal principal,
176 krb5_realm *realms, *r;
177 krb5_boolean result = FALSE;
179 /* multi-component principals can never match */
180 if(krb5_principal_get_comp_string(context, principal, 1) != NULL)
183 ret = krb5_get_default_realms (context, &realms);
187 for (r = realms; *r != NULL; ++r) {
188 if(strcmp(krb5_principal_get_realm(context, principal),
191 if(strcmp(krb5_principal_get_comp_string(context, principal, 0),
197 krb5_free_host_realm (context, realms);
202 * This function takes the name of a local user and checks if
203 * principal is allowed to log in as that user.
205 * The user may have a ~/.k5login file listing principals that are
206 * allowed to login as that user. If that file does not exist, all
207 * principals with a first component identical to the username, and a
208 * realm considered local, are allowed access.
210 * The .k5login file must contain one principal per line, be owned by
211 * user and not be writable by group or other (but must be readable by
214 * Note that if the file exists, no implicit access rights are given
215 * to user@@LOCALREALM.
217 * Optionally, a set of files may be put in ~/.k5login.d (a
218 * directory), in which case they will all be checked in the same
219 * manner as .k5login. The files may be called anything, but files
220 * starting with a hash (#) , or ending with a tilde (~) are
221 * ignored. Subdirectories are not traversed. Note that this directory
222 * may not be checked by other Kerberos implementations.
224 * If no configuration file exists, match user against local domains,
225 * ie luser@@LOCAL-REALMS-IN-CONFIGURATION-FILES.
227 * @param context Kerberos 5 context.
228 * @param principal principal to check if allowed to login
229 * @param luser local user id
231 * @return returns TRUE if access should be granted, FALSE otherwise.
233 * @ingroup krb5_support
236 KRB5_LIB_FUNCTION krb5_boolean KRB5_LIB_CALL
237 krb5_kuserok (krb5_context context,
238 krb5_principal principal,
244 struct passwd *pwd = NULL;
245 char *profile_dir = NULL;
247 krb5_boolean result = FALSE;
249 krb5_boolean found_file = FALSE;
251 #ifdef POSIX_GETPWNAM_R
255 if(getpwnam_r(luser, &pw, pwbuf, sizeof(pwbuf), &pwd) != 0)
258 pwd = getpwnam (luser);
262 profile_dir = pwd->pw_dir;
264 #define KLOGIN "/.k5login"
265 buflen = strlen(profile_dir) + sizeof(KLOGIN) + 2; /* 2 for .d */
266 buf = malloc(buflen);
269 /* check user's ~/.k5login */
270 strlcpy(buf, profile_dir, buflen);
271 strlcat(buf, KLOGIN, buflen);
272 ret = check_one_file(context, buf, pwd, principal, &result);
274 if(ret == 0 && result == TRUE) {
282 strlcat(buf, ".d", buflen);
283 ret = check_directory(context, buf, pwd, principal, &result);
285 if(ret == 0 && result == TRUE)
288 if(ret != ENOENT && ret != ENOTDIR)
291 /* finally if no files exist, allow all principals matching
292 <localuser>@<LOCALREALM> */
293 if(found_file == FALSE)
294 return match_local_principals(context, principal, luser);
298 /* The .k5login file may be on a remote profile and we don't have
299 access to the profile until we have a token handle for the
300 user's credentials. */
301 return match_local_principals(context, principal, luser);