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4a13b9d5 MP |
1 | /* -*- c-file-style: "linux"; -*- |
2 | ||
3 | Copyright (C) 1998-2000 by Andrew Tridgell | |
31593dd6 AT |
4 | |
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. | |
9 | ||
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. | |
14 | ||
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. | |
18 | */ | |
19 | ||
20 | /* support rsync authentication */ | |
21 | #include "rsync.h" | |
22 | ||
bcb7e502 AT |
23 | /*************************************************************************** |
24 | encode a buffer using base64 - simple and slow algorithm. null terminates | |
25 | the result. | |
26 | ***************************************************************************/ | |
27 | static void base64_encode(char *buf, int len, char *out) | |
28 | { | |
29 | char *b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; | |
30 | int bit_offset, byte_offset, idx, i; | |
31 | unsigned char *d = (unsigned char *)buf; | |
bcb7e502 AT |
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 | ||
37f9805d | 59 | strlcpy((char *)input, addr, 17); |
3060d4aa | 60 | sys_gettimeofday(&tv); |
bcb7e502 AT |
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; | |
e42c9458 AT |
77 | char line[MAXPATHLEN]; |
78 | char *p, *pass=NULL; | |
d1be2312 DD |
79 | STRUCT_STAT st; |
80 | int ok = 1; | |
81 | extern int am_root; | |
bcb7e502 AT |
82 | |
83 | if (!fname || !*fname) return 0; | |
84 | ||
85 | fd = open(fname,O_RDONLY); | |
86 | if (fd == -1) return 0; | |
87 | ||
d1be2312 | 88 | if (do_stat(fname, &st) == -1) { |
a039749b | 89 | rsyserr(FERROR, errno, "stat(%s)", fname); |
d1be2312 | 90 | ok = 0; |
3ca8e68f DD |
91 | } else if (lp_strict_modes(module)) { |
92 | if ((st.st_mode & 06) != 0) { | |
93 | rprintf(FERROR,"secrets file must not be other-accessible (see strict modes option)\n"); | |
94 | ok = 0; | |
95 | } else if (am_root && (st.st_uid != 0)) { | |
96 | rprintf(FERROR,"secrets file must be owned by root when running as root (see strict modes)\n"); | |
97 | ok = 0; | |
98 | } | |
d1be2312 DD |
99 | } |
100 | if (!ok) { | |
101 | rprintf(FERROR,"continuing without secrets file\n"); | |
102 | close(fd); | |
103 | return 0; | |
104 | } | |
105 | ||
bcb7e502 AT |
106 | while (!found) { |
107 | int i = 0; | |
707de534 MP |
108 | memset(line, 0, sizeof line); |
109 | while ((size_t) i < (sizeof(line)-1)) { | |
bcb7e502 AT |
110 | if (read(fd, &line[i], 1) != 1) { |
111 | memset(line, 0, sizeof(line)); | |
112 | close(fd); | |
113 | return 0; | |
114 | } | |
115 | if (line[i] == '\r') continue; | |
116 | if (line[i] == '\n') break; | |
117 | i++; | |
118 | } | |
119 | line[i] = 0; | |
120 | if (line[0] == '#') continue; | |
121 | p = strchr(line,':'); | |
122 | if (!p) continue; | |
123 | *p = 0; | |
124 | if (strcmp(user, line)) continue; | |
125 | pass = p+1; | |
126 | found = 1; | |
127 | } | |
128 | ||
129 | close(fd); | |
130 | if (!found) return 0; | |
131 | ||
1a016bfd | 132 | strlcpy(secret, pass, len); |
bcb7e502 AT |
133 | return 1; |
134 | } | |
135 | ||
65575e96 AT |
136 | static char *getpassf(char *filename) |
137 | { | |
138 | char buffer[100]; | |
65575e96 AT |
139 | int fd=0; |
140 | STRUCT_STAT st; | |
141 | int ok = 1; | |
142 | extern int am_root; | |
143 | char *envpw=getenv("RSYNC_PASSWORD"); | |
144 | ||
145 | if (!filename) return NULL; | |
146 | ||
147 | if ( (fd=open(filename,O_RDONLY)) == -1) { | |
4a13b9d5 | 148 | rsyserr(FERROR, errno, "could not open password file \"%s\"",filename); |
65575e96 AT |
149 | if (envpw) rprintf(FERROR,"falling back to RSYNC_PASSWORD environment variable.\n"); |
150 | return NULL; | |
151 | } | |
152 | ||
153 | if (do_stat(filename, &st) == -1) { | |
a039749b | 154 | rsyserr(FERROR, errno, "stat(%s)", filename); |
65575e96 AT |
155 | ok = 0; |
156 | } else if ((st.st_mode & 06) != 0) { | |
157 | rprintf(FERROR,"password file must not be other-accessible\n"); | |
158 | ok = 0; | |
159 | } else if (am_root && (st.st_uid != 0)) { | |
160 | rprintf(FERROR,"password file must be owned by root when running as root\n"); | |
161 | ok = 0; | |
162 | } | |
163 | if (!ok) { | |
164 | rprintf(FERROR,"continuing without password file\n"); | |
165 | if (envpw) rprintf(FERROR,"using RSYNC_PASSWORD environment variable.\n"); | |
166 | close(fd); | |
167 | return NULL; | |
168 | } | |
169 | ||
170 | if (envpw) rprintf(FERROR,"RSYNC_PASSWORD environment variable ignored\n"); | |
171 | ||
172 | buffer[sizeof(buffer)-1]='\0'; | |
ae682c3e | 173 | if (read(fd,buffer,sizeof(buffer)-1) > 0) |
65575e96 | 174 | { |
379e689d | 175 | char *p = strtok(buffer,"\n\r"); |
65575e96 | 176 | close(fd); |
379e689d AT |
177 | if (p) p = strdup(p); |
178 | return p; | |
65575e96 AT |
179 | } |
180 | ||
181 | return NULL; | |
182 | } | |
183 | ||
bcb7e502 | 184 | /* generate a 16 byte hash from a password and challenge */ |
6e4fb64e | 185 | static void generate_hash(char *in, char *challenge, char *out) |
bcb7e502 AT |
186 | { |
187 | char buf[16]; | |
188 | ||
189 | sum_init(); | |
190 | sum_update(in, strlen(in)); | |
191 | sum_update(challenge, strlen(challenge)); | |
192 | sum_end(buf); | |
193 | ||
194 | base64_encode(buf, 16, out); | |
195 | } | |
196 | ||
197 | /* possible negotiate authentication with the client. Use "leader" to | |
d0d56395 AT |
198 | start off the auth if necessary |
199 | ||
200 | return NULL if authentication failed | |
201 | ||
202 | return "" if anonymous access | |
203 | ||
204 | otherwise return username | |
205 | */ | |
206 | char *auth_server(int fd, int module, char *addr, char *leader) | |
bcb7e502 AT |
207 | { |
208 | char *users = lp_auth_users(module); | |
209 | char challenge[16]; | |
210 | char b64_challenge[30]; | |
e42c9458 | 211 | char line[MAXPATHLEN]; |
d0d56395 | 212 | static char user[100]; |
bcb7e502 AT |
213 | char secret[100]; |
214 | char pass[30]; | |
215 | char pass2[30]; | |
c8e78d87 | 216 | char *tok; |
bcb7e502 AT |
217 | |
218 | /* if no auth list then allow anyone in! */ | |
d0d56395 | 219 | if (!users || !*users) return ""; |
bcb7e502 AT |
220 | |
221 | gen_challenge(addr, challenge); | |
222 | ||
223 | base64_encode(challenge, 16, b64_challenge); | |
224 | ||
225 | io_printf(fd,"%s%s\n", leader, b64_challenge); | |
226 | ||
227 | if (!read_line(fd, line, sizeof(line)-1)) { | |
d0d56395 | 228 | return NULL; |
bcb7e502 AT |
229 | } |
230 | ||
231 | memset(user, 0, sizeof(user)); | |
232 | memset(pass, 0, sizeof(pass)); | |
233 | ||
234 | if (sscanf(line,"%99s %29s", user, pass) != 2) { | |
d0d56395 | 235 | return NULL; |
bcb7e502 | 236 | } |
5d78a102 | 237 | |
c8e78d87 | 238 | users = strdup(users); |
d0d56395 | 239 | if (!users) return NULL; |
c8e78d87 AT |
240 | |
241 | for (tok=strtok(users," ,\t"); tok; tok = strtok(NULL," ,\t")) { | |
5d78a102 | 242 | if (fnmatch(tok, user, 0) == 0) break; |
c8e78d87 AT |
243 | } |
244 | free(users); | |
245 | ||
246 | if (!tok) { | |
d0d56395 | 247 | return NULL; |
c8e78d87 AT |
248 | } |
249 | ||
bcb7e502 AT |
250 | memset(secret, 0, sizeof(secret)); |
251 | if (!get_secret(module, user, secret, sizeof(secret)-1)) { | |
252 | memset(secret, 0, sizeof(secret)); | |
d0d56395 | 253 | return NULL; |
bcb7e502 AT |
254 | } |
255 | ||
256 | generate_hash(secret, b64_challenge, pass2); | |
257 | memset(secret, 0, sizeof(secret)); | |
258 | ||
d0d56395 AT |
259 | if (strcmp(pass, pass2) == 0) |
260 | return user; | |
261 | ||
262 | return NULL; | |
bcb7e502 AT |
263 | } |
264 | ||
265 | ||
266 | void auth_client(int fd, char *user, char *challenge) | |
267 | { | |
268 | char *pass; | |
269 | char pass2[30]; | |
65575e96 | 270 | extern char *password_file; |
bcb7e502 AT |
271 | |
272 | if (!user || !*user) return; | |
273 | ||
65575e96 | 274 | if (!(pass=getpassf(password_file)) && !(pass=getenv("RSYNC_PASSWORD"))) { |
64bd7568 MP |
275 | /* XXX: cyeoh says that getpass is deprecated, because |
276 | it may return a truncated password on some systems, | |
277 | and it is not in the LSB. */ | |
bcb7e502 AT |
278 | pass = getpass("Password: "); |
279 | } | |
280 | ||
281 | if (!pass || !*pass) { | |
282 | pass = ""; | |
283 | } | |
284 | ||
285 | generate_hash(pass, challenge, pass2); | |
bcb7e502 AT |
286 | io_printf(fd, "%s %s\n", user, pass2); |
287 | } | |
288 | ||
65575e96 | 289 |