Commit | Line | Data |
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31593dd6 AT |
1 | /* |
2 | Copyright (C) Andrew Tridgell 1998 | |
3 | ||
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. | |
8 | ||
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. | |
13 | ||
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. | |
17 | */ | |
18 | ||
19 | /* support rsync authentication */ | |
20 | #include "rsync.h" | |
21 | ||
bcb7e502 AT |
22 | /*************************************************************************** |
23 | encode a buffer using base64 - simple and slow algorithm. null terminates | |
24 | the result. | |
25 | ***************************************************************************/ | |
26 | static void base64_encode(char *buf, int len, char *out) | |
27 | { | |
28 | char *b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; | |
29 | int bit_offset, byte_offset, idx, i; | |
30 | unsigned char *d = (unsigned char *)buf; | |
31 | char *p; | |
32 | int bytes = (len*8 + 5)/6; | |
33 | ||
34 | memset(out, 0, bytes+1); | |
35 | ||
36 | for (i=0;i<bytes;i++) { | |
37 | byte_offset = (i*6)/8; | |
38 | bit_offset = (i*6)%8; | |
39 | if (bit_offset < 3) { | |
40 | idx = (d[byte_offset] >> (2-bit_offset)) & 0x3F; | |
41 | } else { | |
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))); | |
45 | } | |
46 | } | |
47 | out[i] = b64[idx]; | |
48 | } | |
49 | } | |
50 | ||
51 | /* create a 16 byte challenge buffer */ | |
52 | static void gen_challenge(char *addr, char *challenge) | |
53 | { | |
54 | char input[32]; | |
55 | struct timeval tv; | |
56 | ||
57 | memset(input, 0, sizeof(input)); | |
58 | ||
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()); | |
64 | ||
65 | sum_init(); | |
66 | sum_update(input, sizeof(input)); | |
67 | sum_end(challenge); | |
68 | } | |
69 | ||
70 | ||
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) | |
74 | { | |
75 | char *fname = lp_secrets_file(module); | |
76 | int fd, found=0; | |
77 | char line[1024]; | |
78 | char *p, *pass; | |
79 | ||
80 | if (!fname || !*fname) return 0; | |
81 | ||
82 | fd = open(fname,O_RDONLY); | |
83 | if (fd == -1) return 0; | |
84 | ||
85 | while (!found) { | |
86 | int i = 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)); | |
91 | close(fd); | |
92 | return 0; | |
93 | } | |
94 | if (line[i] == '\r') continue; | |
95 | if (line[i] == '\n') break; | |
96 | i++; | |
97 | } | |
98 | line[i] = 0; | |
99 | if (line[0] == '#') continue; | |
100 | p = strchr(line,':'); | |
101 | if (!p) continue; | |
102 | *p = 0; | |
103 | if (strcmp(user, line)) continue; | |
104 | pass = p+1; | |
105 | found = 1; | |
106 | } | |
107 | ||
108 | close(fd); | |
109 | if (!found) return 0; | |
110 | ||
111 | if (strlen(pass) > len-1) { | |
112 | memset(line, 0, sizeof(line)); | |
113 | return 0; | |
114 | } | |
115 | ||
116 | strcpy(secret, pass); | |
117 | return 1; | |
118 | } | |
119 | ||
120 | /* generate a 16 byte hash from a password and challenge */ | |
121 | void generate_hash(char *in, char *challenge, char *out) | |
122 | { | |
123 | char buf[16]; | |
124 | ||
125 | sum_init(); | |
126 | sum_update(in, strlen(in)); | |
127 | sum_update(challenge, strlen(challenge)); | |
128 | sum_end(buf); | |
129 | ||
130 | base64_encode(buf, 16, out); | |
131 | } | |
132 | ||
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) | |
136 | { | |
137 | char *users = lp_auth_users(module); | |
138 | char challenge[16]; | |
139 | char b64_challenge[30]; | |
140 | char line[1024]; | |
141 | char user[100]; | |
142 | char secret[100]; | |
143 | char pass[30]; | |
144 | char pass2[30]; | |
c8e78d87 | 145 | char *tok; |
bcb7e502 AT |
146 | |
147 | /* if no auth list then allow anyone in! */ | |
148 | if (!users || !*users) return 1; | |
149 | ||
150 | gen_challenge(addr, challenge); | |
151 | ||
152 | base64_encode(challenge, 16, b64_challenge); | |
153 | ||
154 | io_printf(fd,"%s%s\n", leader, b64_challenge); | |
155 | ||
156 | if (!read_line(fd, line, sizeof(line)-1)) { | |
157 | return 0; | |
158 | } | |
159 | ||
160 | memset(user, 0, sizeof(user)); | |
161 | memset(pass, 0, sizeof(pass)); | |
162 | ||
163 | if (sscanf(line,"%99s %29s", user, pass) != 2) { | |
164 | return 0; | |
165 | } | |
166 | ||
c8e78d87 AT |
167 | users = strdup(users); |
168 | if (!users) return 0; | |
169 | ||
170 | for (tok=strtok(users," ,\t"); tok; tok = strtok(NULL," ,\t")) { | |
171 | if (strcmp(tok, user) == 0) break; | |
172 | } | |
173 | free(users); | |
174 | ||
175 | if (!tok) { | |
176 | return 0; | |
177 | } | |
178 | ||
bcb7e502 AT |
179 | memset(secret, 0, sizeof(secret)); |
180 | if (!get_secret(module, user, secret, sizeof(secret)-1)) { | |
181 | memset(secret, 0, sizeof(secret)); | |
182 | return 0; | |
183 | } | |
184 | ||
185 | generate_hash(secret, b64_challenge, pass2); | |
186 | memset(secret, 0, sizeof(secret)); | |
187 | ||
188 | return (strcmp(pass, pass2) == 0); | |
189 | } | |
190 | ||
191 | ||
192 | void auth_client(int fd, char *user, char *challenge) | |
193 | { | |
194 | char *pass; | |
195 | char pass2[30]; | |
196 | ||
197 | if (!user || !*user) return; | |
198 | ||
199 | if (!(pass=getenv("RSYNC_PASSWORD"))) { | |
200 | pass = getpass("Password: "); | |
201 | } | |
202 | ||
203 | if (!pass || !*pass) { | |
204 | pass = ""; | |
205 | } | |
206 | ||
207 | generate_hash(pass, challenge, pass2); | |
208 | ||
209 | io_printf(fd, "%s %s\n", user, pass2); | |
210 | } | |
211 |