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;
32 int bytes = (len*8 + 5)/6;
34 memset(out, 0, bytes+1);
36 for (i=0;i<bytes;i++) {
37 byte_offset = (i*6)/8;
40 idx = (d[byte_offset] >> (2-bit_offset)) & 0x3F;
42 idx = (d[byte_offset] << (bit_offset-2)) & 0x3F;
43 if (byte_offset+1 < len) {
44 idx |= (d[byte_offset+1] >> (8-(bit_offset-2)));
51 /* create a 16 byte challenge buffer */
52 static void gen_challenge(char *addr, char *challenge)
57 memset(input, 0, sizeof(input));
59 strncpy((char *)input, addr, 16);
60 gettimeofday(&tv, NULL);
61 SIVAL(input, 16, tv.tv_sec);
62 SIVAL(input, 20, tv.tv_usec);
63 SIVAL(input, 24, getpid());
66 sum_update(input, sizeof(input));
71 /* return the secret for a user from the sercret file. maximum length
72 is len. null terminate it */
73 static int get_secret(int module, char *user, char *secret, int len)
75 char *fname = lp_secrets_file(module);
80 if (!fname || !*fname) return 0;
82 fd = open(fname,O_RDONLY);
83 if (fd == -1) return 0;
87 memset(line, 0, sizeof(line));
88 while (i<(sizeof(line)-1)) {
89 if (read(fd, &line[i], 1) != 1) {
90 memset(line, 0, sizeof(line));
94 if (line[i] == '\r') continue;
95 if (line[i] == '\n') break;
99 if (line[0] == '#') continue;
100 p = strchr(line,':');
103 if (strcmp(user, line)) continue;
109 if (!found) return 0;
111 if (strlen(pass) > len-1) {
112 memset(line, 0, sizeof(line));
116 strcpy(secret, pass);
120 /* generate a 16 byte hash from a password and challenge */
121 void generate_hash(char *in, char *challenge, char *out)
126 sum_update(in, strlen(in));
127 sum_update(challenge, strlen(challenge));
130 base64_encode(buf, 16, out);
133 /* possible negotiate authentication with the client. Use "leader" to
134 start off the auth if necessary */
135 int auth_server(int fd, int module, char *addr, char *leader)
137 char *users = lp_auth_users(module);
139 char b64_challenge[30];
147 /* if no auth list then allow anyone in! */
148 if (!users || !*users) return 1;
150 gen_challenge(addr, challenge);
152 base64_encode(challenge, 16, b64_challenge);
154 io_printf(fd,"%s%s\n", leader, b64_challenge);
156 if (!read_line(fd, line, sizeof(line)-1)) {
160 memset(user, 0, sizeof(user));
161 memset(pass, 0, sizeof(pass));
163 if (sscanf(line,"%99s %29s", user, pass) != 2) {
167 users = strdup(users);
168 if (!users) return 0;
170 for (tok=strtok(users," ,\t"); tok; tok = strtok(NULL," ,\t")) {
171 if (strcmp(tok, user) == 0) break;
179 memset(secret, 0, sizeof(secret));
180 if (!get_secret(module, user, secret, sizeof(secret)-1)) {
181 memset(secret, 0, sizeof(secret));
185 generate_hash(secret, b64_challenge, pass2);
186 memset(secret, 0, sizeof(secret));
188 return (strcmp(pass, pass2) == 0);
192 void auth_client(int fd, char *user, char *challenge)
197 if (!user || !*user) return;
199 if (!(pass=getenv("RSYNC_PASSWORD"))) {
200 pass = getpass("Password: ");
203 if (!pass || !*pass) {
207 generate_hash(pass, challenge, pass2);
209 io_printf(fd, "%s %s\n", user, pass2);