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;
25 /***************************************************************************
26 encode a buffer using base64 - simple and slow algorithm. null terminates
28 ***************************************************************************/
29 void base64_encode(char *buf, int len, char *out)
31 char *b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
32 int bit_offset, byte_offset, idx, i;
33 unsigned char *d = (unsigned char *)buf;
34 int bytes = (len*8 + 5)/6;
36 memset(out, 0, bytes+1);
38 for (i = 0; i < bytes; i++) {
39 byte_offset = (i*6)/8;
42 idx = (d[byte_offset] >> (2-bit_offset)) & 0x3F;
44 idx = (d[byte_offset] << (bit_offset-2)) & 0x3F;
45 if (byte_offset+1 < len) {
46 idx |= (d[byte_offset+1] >> (8-(bit_offset-2)));
53 /* Generate a challenge buffer and return it base64-encoded. */
54 static void gen_challenge(char *addr, char *challenge)
57 char md4_out[MD4_SUM_LENGTH];
60 memset(input, 0, sizeof input);
62 strlcpy((char *)input, addr, 17);
63 sys_gettimeofday(&tv);
64 SIVAL(input, 16, tv.tv_sec);
65 SIVAL(input, 20, tv.tv_usec);
66 SIVAL(input, 24, getpid());
69 sum_update(input, sizeof input);
72 base64_encode(md4_out, MD4_SUM_LENGTH, challenge);
76 /* Return the secret for a user from the secret file, null terminated.
77 * Maximum length is len (not counting the null). */
78 static int get_secret(int module, char *user, char *secret, int len)
80 char *fname = lp_secrets_file(module);
85 if (!fname || !*fname)
88 if ((fd = open(fname, O_RDONLY)) < 0)
91 if (do_stat(fname, &st) == -1) {
92 rsyserr(FLOG, errno, "stat(%s)", fname);
94 } else if (lp_strict_modes(module)) {
95 if ((st.st_mode & 06) != 0) {
96 rprintf(FLOG, "secrets file must not be other-accessible (see strict modes option)\n");
98 } else if (MY_UID() == 0 && st.st_uid != 0) {
99 rprintf(FLOG, "secrets file must be owned by root when running as root (see strict modes)\n");
104 rprintf(FLOG, "continuing without secrets file\n");
110 /* Reject attempt to match a comment. */
115 /* Try to find a line that starts with the user name and a ':'. */
118 if (read(fd, &ch, 1) != 1) {
127 else if (!*p && ch == ':')
134 /* Slurp the secret into the "secret" buffer. */
137 if (read(fd, p, 1) != 1 || *p == '\n')
150 static char *getpassf(char *filename)
153 char buffer[512], *p;
155 char *envpw = getenv("RSYNC_PASSWORD");
160 if ((fd = open(filename,O_RDONLY)) < 0) {
161 rsyserr(FERROR, errno, "could not open password file \"%s\"",
164 rprintf(FERROR, "falling back to RSYNC_PASSWORD environment variable.\n");
168 if (do_stat(filename, &st) == -1) {
169 rsyserr(FERROR, errno, "stat(%s)", filename);
171 } else if ((st.st_mode & 06) != 0) {
172 rprintf(FERROR,"password file must not be other-accessible\n");
174 } else if (MY_UID() == 0 && st.st_uid != 0) {
175 rprintf(FERROR,"password file must be owned by root when running as root\n");
179 rprintf(FERROR,"continuing without password file\n");
181 rprintf(FERROR, "using RSYNC_PASSWORD environment variable.\n");
187 rprintf(FERROR, "RSYNC_PASSWORD environment variable ignored\n");
189 n = read(fd, buffer, sizeof buffer - 1);
193 if ((p = strtok(buffer, "\n\r")) != NULL)
200 /* Generate an MD4 hash created from the combination of the password
201 * and the challenge string and return it base64-encoded. */
202 static void generate_hash(char *in, char *challenge, char *out)
204 char buf[MD4_SUM_LENGTH];
207 sum_update(in, strlen(in));
208 sum_update(challenge, strlen(challenge));
211 base64_encode(buf, MD4_SUM_LENGTH, out);
214 /* Possibly negotiate authentication with the client. Use "leader" to
215 * start off the auth if necessary.
217 * Return NULL if authentication failed. Return "" if anonymous access.
218 * Otherwise return username.
220 char *auth_server(int f_in, int f_out, int module, char *host, char *addr,
223 char *users = lp_auth_users(module);
224 char challenge[MD4_SUM_LENGTH*2];
225 char line[BIGPATHBUFLEN];
227 char pass2[MD4_SUM_LENGTH*2];
230 /* if no auth list then allow anyone in! */
231 if (!users || !*users)
234 gen_challenge(addr, challenge);
236 io_printf(f_out, "%s%s\n", leader, challenge);
238 if (!read_line(f_in, line, sizeof line - 1)
239 || (pass = strchr(line, ' ')) == NULL) {
240 rprintf(FLOG, "auth failed on module %s from %s (%s): "
241 "invalid challenge response\n",
242 lp_name(module), host, addr);
247 if (!(users = strdup(users)))
248 out_of_memory("auth_server");
250 for (tok = strtok(users, " ,\t"); tok; tok = strtok(NULL, " ,\t")) {
251 if (wildmatch(tok, line))
257 rprintf(FLOG, "auth failed on module %s from %s (%s): "
258 "unauthorized user\n",
259 lp_name(module), host, addr);
263 memset(secret, 0, sizeof secret);
264 if (!get_secret(module, line, secret, sizeof secret - 1)) {
265 memset(secret, 0, sizeof secret);
266 rprintf(FLOG, "auth failed on module %s from %s (%s): "
267 "missing secret for user \"%s\"\n",
268 lp_name(module), host, addr, line);
272 generate_hash(secret, challenge, pass2);
273 memset(secret, 0, sizeof secret);
275 if (strcmp(pass, pass2) != 0) {
276 rprintf(FLOG, "auth failed on module %s from %s (%s): "
277 "password mismatch\n",
278 lp_name(module), host, addr);
286 void auth_client(int fd, char *user, char *challenge)
289 char pass2[MD4_SUM_LENGTH*2];
294 if (!(pass = getpassf(password_file))
295 && !(pass = getenv("RSYNC_PASSWORD"))) {
296 /* XXX: cyeoh says that getpass is deprecated, because
297 * it may return a truncated password on some systems,
298 * and it is not in the LSB.
300 * Andrew Klein says that getpassphrase() is present
301 * on Solaris and reads up to 256 characters.
303 * OpenBSD has a readpassphrase() that might be more suitable.
305 pass = getpass("Password: ");
311 generate_hash(pass, challenge, pass2);
312 io_printf(fd, "%s %s\n", user, pass2);