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Commit | Line | Data |
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0f78b815 WD |
1 | /* |
2 | * Support rsync daemon authentication. | |
3 | * | |
4 | * Copyright (C) 1998-2000 Andrew Tridgell | |
c5fabfb0 | 5 | * Copyright (C) 2002-2020 Wayne Davison |
0f78b815 WD |
6 | * |
7 | * This program is free software; you can redistribute it and/or modify | |
8e41b68e WD |
8 | * it under the terms of the GNU General Public License as published by |
9 | * the Free Software Foundation; either version 3 of the License, or | |
10 | * (at your option) any later version. | |
0f78b815 WD |
11 | * |
12 | * This program is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | * GNU General Public License for more details. | |
16 | * | |
e7c67065 | 17 | * You should have received a copy of the GNU General Public License along |
4fd842f9 | 18 | * with this program; if not, visit the http://fsf.org website. |
0f78b815 | 19 | */ |
18cc8c7e | 20 | |
31593dd6 | 21 | #include "rsync.h" |
5ebe9a46 | 22 | #include "itypes.h" |
11eb67ee | 23 | #include "ifuncs.h" |
31593dd6 | 24 | |
5ebe9a46 | 25 | extern int read_only; |
38cab94d | 26 | extern char *password_file; |
38cab94d | 27 | |
bcb7e502 AT |
28 | /*************************************************************************** |
29 | encode a buffer using base64 - simple and slow algorithm. null terminates | |
30 | the result. | |
31 | ***************************************************************************/ | |
4a19c3b2 | 32 | void base64_encode(const char *buf, int len, char *out, int pad) |
bcb7e502 AT |
33 | { |
34 | char *b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; | |
35 | int bit_offset, byte_offset, idx, i; | |
4a19c3b2 | 36 | const uchar *d = (const uchar *)buf; |
bcb7e502 AT |
37 | int bytes = (len*8 + 5)/6; |
38 | ||
57385128 | 39 | for (i = 0; i < bytes; i++) { |
bcb7e502 AT |
40 | byte_offset = (i*6)/8; |
41 | bit_offset = (i*6)%8; | |
42 | if (bit_offset < 3) { | |
43 | idx = (d[byte_offset] >> (2-bit_offset)) & 0x3F; | |
44 | } else { | |
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))); | |
48 | } | |
49 | } | |
50 | out[i] = b64[idx]; | |
51 | } | |
293def60 WD |
52 | |
53 | while (pad && (i % 4)) | |
54 | out[i++] = '='; | |
55 | ||
56 | out[i] = '\0'; | |
bcb7e502 AT |
57 | } |
58 | ||
bf011fed | 59 | /* Generate a challenge buffer and return it base64-encoded. */ |
4a19c3b2 | 60 | static void gen_challenge(const char *addr, char *challenge) |
bcb7e502 AT |
61 | { |
62 | char input[32]; | |
a0456b9c | 63 | char digest[MAX_DIGEST_LEN]; |
bcb7e502 | 64 | struct timeval tv; |
a0456b9c | 65 | int len; |
bcb7e502 | 66 | |
58c9b4b7 | 67 | memset(input, 0, sizeof input); |
bcb7e502 | 68 | |
4a19c3b2 | 69 | strlcpy(input, addr, 17); |
3060d4aa | 70 | sys_gettimeofday(&tv); |
bcb7e502 AT |
71 | SIVAL(input, 16, tv.tv_sec); |
72 | SIVAL(input, 20, tv.tv_usec); | |
73 | SIVAL(input, 24, getpid()); | |
74 | ||
a5a7d3a2 | 75 | sum_init(-1, 0); |
58c9b4b7 | 76 | sum_update(input, sizeof input); |
a0456b9c | 77 | len = sum_end(digest); |
bf011fed | 78 | |
a0456b9c | 79 | base64_encode(digest, len, challenge, 0); |
bcb7e502 AT |
80 | } |
81 | ||
5ebe9a46 WD |
82 | /* Generate an MD4 hash created from the combination of the password |
83 | * and the challenge string and return it base64-encoded. */ | |
84 | static void generate_hash(const char *in, const char *challenge, char *out) | |
85 | { | |
86 | char buf[MAX_DIGEST_LEN]; | |
87 | int len; | |
88 | ||
a5a7d3a2 | 89 | sum_init(-1, 0); |
5ebe9a46 WD |
90 | sum_update(in, strlen(in)); |
91 | sum_update(challenge, strlen(challenge)); | |
92 | len = sum_end(buf); | |
93 | ||
94 | base64_encode(buf, len, out, 0); | |
95 | } | |
bcb7e502 | 96 | |
38cab94d WD |
97 | /* Return the secret for a user from the secret file, null terminated. |
98 | * Maximum length is len (not counting the null). */ | |
5ebe9a46 WD |
99 | static const char *check_secret(int module, const char *user, const char *group, |
100 | const char *challenge, const char *pass) | |
bcb7e502 | 101 | { |
5ebe9a46 WD |
102 | char line[1024]; |
103 | char pass2[MAX_DIGEST_LEN*2]; | |
4a19c3b2 | 104 | const char *fname = lp_secrets_file(module); |
d1be2312 | 105 | STRUCT_STAT st; |
0dedfbce | 106 | int ok = 1; |
5ebe9a46 WD |
107 | int user_len = strlen(user); |
108 | int group_len = group ? strlen(group) : 0; | |
109 | char *err; | |
0dedfbce | 110 | FILE *fh; |
bcb7e502 | 111 | |
0dedfbce | 112 | if (!fname || !*fname || (fh = fopen(fname, "r")) == NULL) |
5ebe9a46 | 113 | return "no secrets file"; |
bcb7e502 | 114 | |
0dedfbce | 115 | if (do_fstat(fileno(fh), &st) == -1) { |
5ebe9a46 | 116 | rsyserr(FLOG, errno, "fstat(%s)", fname); |
d1be2312 | 117 | ok = 0; |
3ca8e68f DD |
118 | } else if (lp_strict_modes(module)) { |
119 | if ((st.st_mode & 06) != 0) { | |
30c041f9 | 120 | rprintf(FLOG, "secrets file must not be other-accessible (see strict modes option)\n"); |
3ca8e68f | 121 | ok = 0; |
59cb358f | 122 | } else if (MY_UID() == ROOT_UID && st.st_uid != ROOT_UID) { |
30c041f9 | 123 | rprintf(FLOG, "secrets file must be owned by root when running as root (see strict modes)\n"); |
3ca8e68f DD |
124 | ok = 0; |
125 | } | |
d1be2312 DD |
126 | } |
127 | if (!ok) { | |
0dedfbce | 128 | fclose(fh); |
5ebe9a46 | 129 | return "ignoring secrets file"; |
d1be2312 DD |
130 | } |
131 | ||
38cab94d WD |
132 | if (*user == '#') { |
133 | /* Reject attempt to match a comment. */ | |
0dedfbce | 134 | fclose(fh); |
5ebe9a46 | 135 | return "invalid username"; |
38cab94d WD |
136 | } |
137 | ||
5ebe9a46 WD |
138 | /* Try to find a line that starts with the user (or @group) name and a ':'. */ |
139 | err = "secret not found"; | |
0dedfbce WD |
140 | while ((user || group) && fgets(line, sizeof line, fh) != NULL) { |
141 | const char **ptr, *s = strtok(line, "\n\r"); | |
5ebe9a46 | 142 | int len; |
0dedfbce WD |
143 | if (!s) |
144 | continue; | |
145 | if (*s == '@') { | |
5ebe9a46 WD |
146 | ptr = &group; |
147 | len = group_len; | |
0dedfbce | 148 | s++; |
5ebe9a46 WD |
149 | } else { |
150 | ptr = &user; | |
151 | len = user_len; | |
38cab94d | 152 | } |
5ebe9a46 WD |
153 | if (!*ptr || strncmp(s, *ptr, len) != 0 || s[len] != ':') |
154 | continue; | |
155 | generate_hash(s+len+1, challenge, pass2); | |
156 | if (strcmp(pass, pass2) == 0) { | |
157 | err = NULL; | |
158 | break; | |
bcb7e502 | 159 | } |
5ebe9a46 WD |
160 | err = "password mismatch"; |
161 | *ptr = NULL; /* Don't look for name again. */ | |
bcb7e502 AT |
162 | } |
163 | ||
0dedfbce | 164 | fclose(fh); |
bcb7e502 | 165 | |
c3761706 WD |
166 | force_memzero(line, sizeof line); |
167 | force_memzero(pass2, sizeof pass2); | |
5ebe9a46 WD |
168 | |
169 | return err; | |
bcb7e502 AT |
170 | } |
171 | ||
4a19c3b2 | 172 | static const char *getpassf(const char *filename) |
65575e96 | 173 | { |
65575e96 | 174 | STRUCT_STAT st; |
38cab94d | 175 | char buffer[512], *p; |
12505e02 | 176 | int n; |
65575e96 | 177 | |
38cab94d WD |
178 | if (!filename) |
179 | return NULL; | |
65575e96 | 180 | |
12505e02 WD |
181 | if (strcmp(filename, "-") == 0) { |
182 | n = fgets(buffer, sizeof buffer, stdin) == NULL ? -1 : (int)strlen(buffer); | |
183 | } else { | |
184 | int fd; | |
18cc8c7e | 185 | |
12505e02 WD |
186 | if ((fd = open(filename,O_RDONLY)) < 0) { |
187 | rsyserr(FERROR, errno, "could not open password file %s", filename); | |
188 | exit_cleanup(RERR_SYNTAX); | |
189 | } | |
190 | ||
191 | if (do_stat(filename, &st) == -1) { | |
192 | rsyserr(FERROR, errno, "stat(%s)", filename); | |
193 | exit_cleanup(RERR_SYNTAX); | |
194 | } | |
195 | if ((st.st_mode & 06) != 0) { | |
196 | rprintf(FERROR, "ERROR: password file must not be other-accessible\n"); | |
197 | exit_cleanup(RERR_SYNTAX); | |
198 | } | |
59cb358f | 199 | if (MY_UID() == ROOT_UID && st.st_uid != ROOT_UID) { |
12505e02 WD |
200 | rprintf(FERROR, "ERROR: password file must be owned by root when running as root\n"); |
201 | exit_cleanup(RERR_SYNTAX); | |
202 | } | |
203 | ||
204 | n = read(fd, buffer, sizeof buffer - 1); | |
205 | close(fd); | |
65575e96 AT |
206 | } |
207 | ||
38cab94d WD |
208 | if (n > 0) { |
209 | buffer[n] = '\0'; | |
210 | if ((p = strtok(buffer, "\n\r")) != NULL) | |
211 | return strdup(p); | |
18cc8c7e | 212 | } |
65575e96 | 213 | |
70c4bfb7 WD |
214 | rprintf(FERROR, "ERROR: failed to read a password from %s\n", filename); |
215 | exit_cleanup(RERR_SYNTAX); | |
65575e96 AT |
216 | } |
217 | ||
18cc8c7e WD |
218 | /* Possibly negotiate authentication with the client. Use "leader" to |
219 | * start off the auth if necessary. | |
220 | * | |
221 | * Return NULL if authentication failed. Return "" if anonymous access. | |
222 | * Otherwise return username. | |
223 | */ | |
4a19c3b2 WD |
224 | char *auth_server(int f_in, int f_out, int module, const char *host, |
225 | const char *addr, const char *leader) | |
bcb7e502 AT |
226 | { |
227 | char *users = lp_auth_users(module); | |
a0456b9c | 228 | char challenge[MAX_DIGEST_LEN*2]; |
d999d312 | 229 | char line[BIGPATHBUFLEN]; |
d6f0342a | 230 | const char **auth_uid_groups = NULL; |
5ebe9a46 WD |
231 | int auth_uid_groups_cnt = -1; |
232 | const char *err = NULL; | |
233 | int group_match = -1; | |
5037cf3a | 234 | char *tok, *pass; |
5ebe9a46 | 235 | char opt_ch = '\0'; |
bcb7e502 AT |
236 | |
237 | /* if no auth list then allow anyone in! */ | |
58c9b4b7 WD |
238 | if (!users || !*users) |
239 | return ""; | |
bcb7e502 AT |
240 | |
241 | gen_challenge(addr, challenge); | |
18cc8c7e | 242 | |
bf011fed | 243 | io_printf(f_out, "%s%s\n", leader, challenge); |
bcb7e502 | 244 | |
5ebe9a46 | 245 | if (!read_line_old(f_in, line, sizeof line, 0) |
5037cf3a WD |
246 | || (pass = strchr(line, ' ')) == NULL) { |
247 | rprintf(FLOG, "auth failed on module %s from %s (%s): " | |
248 | "invalid challenge response\n", | |
249 | lp_name(module), host, addr); | |
d0d56395 | 250 | return NULL; |
5037cf3a WD |
251 | } |
252 | *pass++ = '\0'; | |
18cc8c7e | 253 | |
11eb67ee | 254 | users = strdup(users); |
c8e78d87 | 255 | |
5037cf3a | 256 | for (tok = strtok(users, " ,\t"); tok; tok = strtok(NULL, " ,\t")) { |
5ebe9a46 WD |
257 | char *opts; |
258 | /* See if the user appended :deny, :ro, or :rw. */ | |
259 | if ((opts = strchr(tok, ':')) != NULL) { | |
260 | *opts++ = '\0'; | |
261 | opt_ch = isUpper(opts) ? toLower(opts) : *opts; | |
262 | if (opt_ch == 'r') { /* handle ro and rw */ | |
263 | opt_ch = isUpper(opts+1) ? toLower(opts+1) : opts[1]; | |
264 | if (opt_ch == 'o') | |
265 | opt_ch = 'r'; | |
266 | else if (opt_ch != 'w') | |
267 | opt_ch = '\0'; | |
268 | } else if (opt_ch != 'd') /* if it's not deny, ignore it */ | |
269 | opt_ch = '\0'; | |
270 | } else | |
271 | opt_ch = '\0'; | |
272 | if (*tok != '@') { | |
273 | /* Match the username */ | |
274 | if (wildmatch(tok, line)) | |
275 | break; | |
276 | } else { | |
277 | #ifdef HAVE_GETGROUPLIST | |
278 | int j; | |
279 | /* See if authorizing user is a real user, and if so, see | |
280 | * if it is in a group that matches tok+1 wildmat. */ | |
281 | if (auth_uid_groups_cnt < 0) { | |
2a7355fb | 282 | item_list gid_list = EMPTY_ITEM_LIST; |
5ebe9a46 | 283 | uid_t auth_uid; |
5ebe9a46 | 284 | if (!user_to_uid(line, &auth_uid, False) |
2a7355fb | 285 | || getallgroups(auth_uid, &gid_list) != NULL) |
5ebe9a46 WD |
286 | auth_uid_groups_cnt = 0; |
287 | else { | |
2a7355fb WD |
288 | gid_t *gid_array = gid_list.items; |
289 | auth_uid_groups_cnt = gid_list.count; | |
d6f0342a | 290 | auth_uid_groups = new_array(const char *, auth_uid_groups_cnt); |
5ebe9a46 | 291 | for (j = 0; j < auth_uid_groups_cnt; j++) |
2a7355fb | 292 | auth_uid_groups[j] = gid_to_group(gid_array[j]); |
5ebe9a46 WD |
293 | } |
294 | } | |
295 | for (j = 0; j < auth_uid_groups_cnt; j++) { | |
296 | if (auth_uid_groups[j] && wildmatch(tok+1, auth_uid_groups[j])) { | |
297 | group_match = j; | |
298 | break; | |
299 | } | |
300 | } | |
301 | if (group_match >= 0) | |
302 | break; | |
303 | #else | |
304 | rprintf(FLOG, "your computer doesn't support getgrouplist(), so no @group authorization is possible.\n"); | |
305 | #endif | |
306 | } | |
c8e78d87 | 307 | } |
5ebe9a46 | 308 | |
c8e78d87 AT |
309 | free(users); |
310 | ||
5ebe9a46 WD |
311 | if (!tok) |
312 | err = "no matching rule"; | |
313 | else if (opt_ch == 'd') | |
314 | err = "denied by rule"; | |
315 | else { | |
d6f0342a | 316 | const char *group = group_match >= 0 ? auth_uid_groups[group_match] : NULL; |
5ebe9a46 | 317 | err = check_secret(module, line, group, challenge, pass); |
5037cf3a | 318 | } |
18cc8c7e | 319 | |
c3761706 WD |
320 | force_memzero(challenge, sizeof challenge); |
321 | force_memzero(pass, strlen(pass)); | |
bcb7e502 | 322 | |
5ebe9a46 WD |
323 | if (auth_uid_groups) { |
324 | int j; | |
325 | for (j = 0; j < auth_uid_groups_cnt; j++) { | |
326 | if (auth_uid_groups[j]) | |
d6f0342a | 327 | free((char*)auth_uid_groups[j]); |
5ebe9a46 WD |
328 | } |
329 | free(auth_uid_groups); | |
330 | } | |
18cc8c7e | 331 | |
5ebe9a46 WD |
332 | if (err) { |
333 | rprintf(FLOG, "auth failed on module %s from %s (%s) for %s: %s\n", | |
334 | lp_name(module), host, addr, line, err); | |
5037cf3a WD |
335 | return NULL; |
336 | } | |
d0d56395 | 337 | |
5ebe9a46 WD |
338 | if (opt_ch == 'r') |
339 | read_only = 1; | |
340 | else if (opt_ch == 'w') | |
341 | read_only = 0; | |
342 | ||
5037cf3a | 343 | return strdup(line); |
bcb7e502 AT |
344 | } |
345 | ||
4a19c3b2 | 346 | void auth_client(int fd, const char *user, const char *challenge) |
bcb7e502 | 347 | { |
4a19c3b2 | 348 | const char *pass; |
a0456b9c | 349 | char pass2[MAX_DIGEST_LEN*2]; |
bcb7e502 | 350 | |
ef383c0d | 351 | if (!user || !*user) |
4b2f6a7c | 352 | user = "nobody"; |
bcb7e502 | 353 | |
58c9b4b7 WD |
354 | if (!(pass = getpassf(password_file)) |
355 | && !(pass = getenv("RSYNC_PASSWORD"))) { | |
64bd7568 | 356 | /* XXX: cyeoh says that getpass is deprecated, because |
908f5a9f MP |
357 | * it may return a truncated password on some systems, |
358 | * and it is not in the LSB. | |
8475e0e4 WD |
359 | * |
360 | * Andrew Klein says that getpassphrase() is present | |
361 | * on Solaris and reads up to 256 characters. | |
362 | * | |
363 | * OpenBSD has a readpassphrase() that might be more suitable. | |
364 | */ | |
bcb7e502 AT |
365 | pass = getpass("Password: "); |
366 | } | |
367 | ||
38cab94d | 368 | if (!pass) |
bcb7e502 | 369 | pass = ""; |
bcb7e502 AT |
370 | |
371 | generate_hash(pass, challenge, pass2); | |
bcb7e502 AT |
372 | io_printf(fd, "%s %s\n", user, pass2); |
373 | } |