1 /* -*- c-file-style: "linux"; -*-
3 Copyright (C) 1998-2000 by Andrew Tridgell
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 /* support rsync authentication */
23 extern char *password_file;
26 /***************************************************************************
27 encode a buffer using base64 - simple and slow algorithm. null terminates
29 ***************************************************************************/
30 void base64_encode(char *buf, int len, char *out)
32 char *b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
33 int bit_offset, byte_offset, idx, i;
34 unsigned char *d = (unsigned char *)buf;
35 int bytes = (len*8 + 5)/6;
37 memset(out, 0, bytes+1);
39 for (i = 0; i < bytes; i++) {
40 byte_offset = (i*6)/8;
43 idx = (d[byte_offset] >> (2-bit_offset)) & 0x3F;
45 idx = (d[byte_offset] << (bit_offset-2)) & 0x3F;
46 if (byte_offset+1 < len) {
47 idx |= (d[byte_offset+1] >> (8-(bit_offset-2)));
54 /* Generate a challenge buffer and return it base64-encoded. */
55 static void gen_challenge(char *addr, char *challenge)
58 char md4_out[MD4_SUM_LENGTH];
61 memset(input, 0, sizeof input);
63 strlcpy((char *)input, addr, 17);
64 sys_gettimeofday(&tv);
65 SIVAL(input, 16, tv.tv_sec);
66 SIVAL(input, 20, tv.tv_usec);
67 SIVAL(input, 24, getpid());
70 sum_update(input, sizeof input);
73 base64_encode(md4_out, MD4_SUM_LENGTH, challenge);
77 /* Return the secret for a user from the secret file, null terminated.
78 * Maximum length is len (not counting the null). */
79 static int get_secret(int module, char *user, char *secret, int len)
81 char *fname = lp_secrets_file(module);
86 if (!fname || !*fname)
89 if ((fd = open(fname, O_RDONLY)) < 0)
92 if (do_stat(fname, &st) == -1) {
93 rsyserr(FLOG, errno, "stat(%s)", safe_fname(fname));
95 } else if (lp_strict_modes(module)) {
96 if ((st.st_mode & 06) != 0) {
97 rprintf(FLOG, "secrets file must not be other-accessible (see strict modes option)\n");
99 } else if (am_root && (st.st_uid != 0)) {
100 rprintf(FLOG, "secrets file must be owned by root when running as root (see strict modes)\n");
105 rprintf(FLOG, "continuing without secrets file\n");
111 /* Reject attempt to match a comment. */
116 /* Try to find a line that starts with the user name and a ':'. */
119 if (read(fd, &ch, 1) != 1) {
128 else if (!*p && ch == ':')
135 /* Slurp the secret into the "secret" buffer. */
138 if (read(fd, p, 1) != 1 || *p == '\n')
151 static char *getpassf(char *filename)
154 char buffer[512], *p;
156 char *envpw = getenv("RSYNC_PASSWORD");
161 if ((fd = open(filename,O_RDONLY)) < 0) {
162 rsyserr(FERROR, errno, "could not open password file \"%s\"",
163 safe_fname(filename));
165 rprintf(FERROR, "falling back to RSYNC_PASSWORD environment variable.\n");
169 if (do_stat(filename, &st) == -1) {
170 rsyserr(FERROR, errno, "stat(%s)", safe_fname(filename));
172 } else if ((st.st_mode & 06) != 0) {
173 rprintf(FERROR,"password file must not be other-accessible\n");
175 } else if (am_root && st.st_uid != 0) {
176 rprintf(FERROR,"password file must be owned by root when running as root\n");
180 rprintf(FERROR,"continuing without password file\n");
182 rprintf(FERROR, "using RSYNC_PASSWORD environment variable.\n");
188 rprintf(FERROR, "RSYNC_PASSWORD environment variable ignored\n");
190 n = read(fd, buffer, sizeof buffer - 1);
194 if ((p = strtok(buffer, "\n\r")) != NULL)
201 /* Generate an MD4 hash created from the combination of the password
202 * and the challenge string and return it base64-encoded. */
203 static void generate_hash(char *in, char *challenge, char *out)
205 char buf[MD4_SUM_LENGTH];
208 sum_update(in, strlen(in));
209 sum_update(challenge, strlen(challenge));
212 base64_encode(buf, MD4_SUM_LENGTH, out);
215 /* Possibly negotiate authentication with the client. Use "leader" to
216 * start off the auth if necessary.
218 * Return NULL if authentication failed. Return "" if anonymous access.
219 * Otherwise return username.
221 char *auth_server(int f_in, int f_out, int module, char *host, char *addr,
224 char *users = lp_auth_users(module);
225 char challenge[MD4_SUM_LENGTH*2];
226 char line[MAXPATHLEN];
228 char pass2[MD4_SUM_LENGTH*2];
231 /* if no auth list then allow anyone in! */
232 if (!users || !*users)
235 gen_challenge(addr, challenge);
237 io_printf(f_out, "%s%s\n", leader, challenge);
239 if (!read_line(f_in, line, sizeof line - 1)
240 || (pass = strchr(line, ' ')) == NULL) {
241 rprintf(FLOG, "auth failed on module %s from %s (%s): "
242 "invalid challenge response\n",
243 lp_name(module), host, addr);
248 if (!(users = strdup(users)))
249 out_of_memory("auth_server");
251 for (tok = strtok(users, " ,\t"); tok; tok = strtok(NULL, " ,\t")) {
252 if (wildmatch(tok, line))
258 rprintf(FLOG, "auth failed on module %s from %s (%s): "
259 "unauthorized user\n",
260 lp_name(module), host, addr);
264 memset(secret, 0, sizeof secret);
265 if (!get_secret(module, line, secret, sizeof secret - 1)) {
266 memset(secret, 0, sizeof secret);
267 rprintf(FLOG, "auth failed on module %s from %s (%s): "
268 "missing secret for user \"%s\"\n",
269 lp_name(module), host, addr, line);
273 generate_hash(secret, challenge, pass2);
274 memset(secret, 0, sizeof secret);
276 if (strcmp(pass, pass2) != 0) {
277 rprintf(FLOG, "auth failed on module %s from %s (%s): "
278 "password mismatch\n",
279 lp_name(module), host, addr);
287 void auth_client(int fd, char *user, char *challenge)
290 char pass2[MD4_SUM_LENGTH*2];
295 if (!(pass = getpassf(password_file))
296 && !(pass = getenv("RSYNC_PASSWORD"))) {
297 /* XXX: cyeoh says that getpass is deprecated, because
298 * it may return a truncated password on some systems,
299 * and it is not in the LSB.
301 * Andrew Klein says that getpassphrase() is present
302 * on Solaris and reads up to 256 characters.
304 * OpenBSD has a readpassphrase() that might be more suitable.
306 pass = getpass("Password: ");
312 generate_hash(pass, challenge, pass2);
313 io_printf(fd, "%s %s\n", user, pass2);