2 Copyright (C) Andrew Tridgell 1998
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 /* support rsync authentication */
22 /***************************************************************************
23 encode a buffer using base64 - simple and slow algorithm. null terminates
25 ***************************************************************************/
26 static void base64_encode(char *buf, int len, char *out)
28 char *b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
29 int bit_offset, byte_offset, idx, i;
30 unsigned char *d = (unsigned char *)buf;
31 int bytes = (len*8 + 5)/6;
33 memset(out, 0, bytes+1);
35 for (i=0;i<bytes;i++) {
36 byte_offset = (i*6)/8;
39 idx = (d[byte_offset] >> (2-bit_offset)) & 0x3F;
41 idx = (d[byte_offset] << (bit_offset-2)) & 0x3F;
42 if (byte_offset+1 < len) {
43 idx |= (d[byte_offset+1] >> (8-(bit_offset-2)));
50 /* create a 16 byte challenge buffer */
51 static void gen_challenge(char *addr, char *challenge)
56 memset(input, 0, sizeof(input));
58 strlcpy((char *)input, addr, 16);
59 gettimeofday(&tv, NULL);
60 SIVAL(input, 16, tv.tv_sec);
61 SIVAL(input, 20, tv.tv_usec);
62 SIVAL(input, 24, getpid());
65 sum_update(input, sizeof(input));
70 /* return the secret for a user from the sercret file. maximum length
71 is len. null terminate it */
72 static int get_secret(int module, char *user, char *secret, int len)
74 char *fname = lp_secrets_file(module);
76 char line[MAXPATHLEN];
79 if (!fname || !*fname) return 0;
81 fd = open(fname,O_RDONLY);
82 if (fd == -1) return 0;
86 memset(line, 0, sizeof(line));
87 while (i<(sizeof(line)-1)) {
88 if (read(fd, &line[i], 1) != 1) {
89 memset(line, 0, sizeof(line));
93 if (line[i] == '\r') continue;
94 if (line[i] == '\n') break;
98 if (line[0] == '#') continue;
102 if (strcmp(user, line)) continue;
108 if (!found) return 0;
110 strlcpy(secret, pass, len);
114 /* generate a 16 byte hash from a password and challenge */
115 void generate_hash(char *in, char *challenge, char *out)
120 sum_update(in, strlen(in));
121 sum_update(challenge, strlen(challenge));
124 base64_encode(buf, 16, out);
127 /* possible negotiate authentication with the client. Use "leader" to
128 start off the auth if necessary */
129 int auth_server(int fd, int module, char *addr, char *leader)
131 char *users = lp_auth_users(module);
133 char b64_challenge[30];
134 char line[MAXPATHLEN];
141 /* if no auth list then allow anyone in! */
142 if (!users || !*users) return 1;
144 gen_challenge(addr, challenge);
146 base64_encode(challenge, 16, b64_challenge);
148 io_printf(fd,"%s%s\n", leader, b64_challenge);
150 if (!read_line(fd, line, sizeof(line)-1)) {
154 memset(user, 0, sizeof(user));
155 memset(pass, 0, sizeof(pass));
157 if (sscanf(line,"%99s %29s", user, pass) != 2) {
161 users = strdup(users);
162 if (!users) return 0;
164 for (tok=strtok(users," ,\t"); tok; tok = strtok(NULL," ,\t")) {
165 if (strcmp(tok, user) == 0) break;
173 memset(secret, 0, sizeof(secret));
174 if (!get_secret(module, user, secret, sizeof(secret)-1)) {
175 memset(secret, 0, sizeof(secret));
179 generate_hash(secret, b64_challenge, pass2);
180 memset(secret, 0, sizeof(secret));
182 return (strcmp(pass, pass2) == 0);
186 void auth_client(int fd, char *user, char *challenge)
191 if (!user || !*user) return;
193 if (!(pass=getenv("RSYNC_PASSWORD"))) {
194 pass = getpass("Password: ");
197 if (!pass || !*pass) {
201 generate_hash(pass, challenge, pass2);
203 io_printf(fd, "%s %s\n", user, pass2);