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 /* create a 16 byte challenge buffer */
55 static void gen_challenge(char *addr, char *challenge)
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);
74 /* Return the secret for a user from the secret file, null terminated.
75 * Maximum length is len (not counting the null). */
76 static int get_secret(int module, char *user, char *secret, int len)
78 char *fname = lp_secrets_file(module);
83 if (!fname || !*fname)
86 if ((fd = open(fname, O_RDONLY)) < 0)
89 if (do_stat(fname, &st) == -1) {
90 rsyserr(FERROR, errno, "stat(%s)", fname);
92 } else if (lp_strict_modes(module)) {
93 if ((st.st_mode & 06) != 0) {
94 rprintf(FERROR,"secrets file must not be other-accessible (see strict modes option)\n");
96 } else if (am_root && (st.st_uid != 0)) {
97 rprintf(FERROR,"secrets file must be owned by root when running as root (see strict modes)\n");
102 rprintf(FERROR,"continuing without secrets file\n");
108 /* Reject attempt to match a comment. */
113 /* Try to find a line that starts with the user name and a ':'. */
116 if (read(fd, &ch, 1) != 1) {
125 else if (!*p && ch == ':')
132 /* Slurp the secret into the "secret" buffer. */
135 if (read(fd, p, 1) != 1 || *p == '\n')
148 static char *getpassf(char *filename)
151 char buffer[512], *p;
153 char *envpw = getenv("RSYNC_PASSWORD");
158 if ((fd = open(filename,O_RDONLY)) < 0) {
159 rsyserr(FERROR, errno, "could not open password file \"%s\"",filename);
161 rprintf(FERROR, "falling back to RSYNC_PASSWORD environment variable.\n");
165 if (do_stat(filename, &st) == -1) {
166 rsyserr(FERROR, errno, "stat(%s)", filename);
168 } else if ((st.st_mode & 06) != 0) {
169 rprintf(FERROR,"password file must not be other-accessible\n");
171 } else if (am_root && st.st_uid != 0) {
172 rprintf(FERROR,"password file must be owned by root when running as root\n");
176 rprintf(FERROR,"continuing without password file\n");
178 rprintf(FERROR, "using RSYNC_PASSWORD environment variable.\n");
184 rprintf(FERROR, "RSYNC_PASSWORD environment variable ignored\n");
186 n = read(fd, buffer, sizeof buffer - 1);
190 if ((p = strtok(buffer, "\n\r")) != NULL)
197 /* generate a 16 byte hash from a password and challenge */
198 static void generate_hash(char *in, char *challenge, char *out)
203 sum_update(in, strlen(in));
204 sum_update(challenge, strlen(challenge));
207 base64_encode(buf, 16, out);
210 /* Possibly negotiate authentication with the client. Use "leader" to
211 * start off the auth if necessary.
213 * Return NULL if authentication failed. Return "" if anonymous access.
214 * Otherwise return username.
216 char *auth_server(int f_in, int f_out, int module, char *addr, char *leader)
218 char *users = lp_auth_users(module);
220 char b64_challenge[30];
221 char line[MAXPATHLEN];
222 static char user[100];
228 /* if no auth list then allow anyone in! */
229 if (!users || !*users)
232 gen_challenge(addr, challenge);
234 base64_encode(challenge, 16, b64_challenge);
236 io_printf(f_out, "%s%s\n", leader, b64_challenge);
238 if (!read_line(f_in, line, sizeof line - 1))
241 memset(user, 0, sizeof user);
242 memset(pass, 0, sizeof pass);
244 if (sscanf(line,"%99s %29s", user, pass) != 2)
247 users = strdup(users);
251 for (tok=strtok(users," ,\t"); tok; tok = strtok(NULL," ,\t")) {
252 if (wildmatch(tok, user))
260 memset(secret, 0, sizeof secret);
261 if (!get_secret(module, user, secret, sizeof secret - 1)) {
262 memset(secret, 0, sizeof secret);
266 generate_hash(secret, b64_challenge, pass2);
267 memset(secret, 0, sizeof secret);
269 if (strcmp(pass, pass2) == 0)
276 void auth_client(int fd, char *user, char *challenge)
284 if (!(pass = getpassf(password_file))
285 && !(pass = getenv("RSYNC_PASSWORD"))) {
286 /* XXX: cyeoh says that getpass is deprecated, because
287 * it may return a truncated password on some systems,
288 * and it is not in the LSB.
290 * Andrew Klein says that getpassphrase() is present
291 * on Solaris and reads up to 256 characters.
293 * OpenBSD has a readpassphrase() that might be more suitable.
295 pass = getpass("Password: ");
301 generate_hash(pass, challenge, pass2);
302 io_printf(fd, "%s %s\n", user, pass2);