Commit | Line | Data |
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4a13b9d5 | 1 | /* -*- c-file-style: "linux"; -*- |
18cc8c7e WD |
2 | |
3 | Copyright (C) 1998-2000 by Andrew Tridgell | |
4 | ||
31593dd6 AT |
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. | |
18cc8c7e | 9 | |
31593dd6 AT |
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. | |
18cc8c7e | 14 | |
31593dd6 AT |
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 | ||
38cab94d | 23 | extern char *password_file; |
38cab94d | 24 | |
bcb7e502 AT |
25 | /*************************************************************************** |
26 | encode a buffer using base64 - simple and slow algorithm. null terminates | |
27 | the result. | |
28 | ***************************************************************************/ | |
57385128 | 29 | void base64_encode(char *buf, int len, char *out) |
bcb7e502 AT |
30 | { |
31 | char *b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; | |
32 | int bit_offset, byte_offset, idx, i; | |
33 | unsigned char *d = (unsigned char *)buf; | |
bcb7e502 AT |
34 | int bytes = (len*8 + 5)/6; |
35 | ||
36 | memset(out, 0, bytes+1); | |
37 | ||
57385128 | 38 | for (i = 0; i < bytes; i++) { |
bcb7e502 AT |
39 | byte_offset = (i*6)/8; |
40 | bit_offset = (i*6)%8; | |
41 | if (bit_offset < 3) { | |
42 | idx = (d[byte_offset] >> (2-bit_offset)) & 0x3F; | |
43 | } else { | |
44 | idx = (d[byte_offset] << (bit_offset-2)) & 0x3F; | |
45 | if (byte_offset+1 < len) { | |
46 | idx |= (d[byte_offset+1] >> (8-(bit_offset-2))); | |
47 | } | |
48 | } | |
49 | out[i] = b64[idx]; | |
50 | } | |
51 | } | |
52 | ||
bf011fed | 53 | /* Generate a challenge buffer and return it base64-encoded. */ |
bcb7e502 AT |
54 | static void gen_challenge(char *addr, char *challenge) |
55 | { | |
56 | char input[32]; | |
bf011fed | 57 | char md4_out[MD4_SUM_LENGTH]; |
bcb7e502 AT |
58 | struct timeval tv; |
59 | ||
58c9b4b7 | 60 | memset(input, 0, sizeof input); |
bcb7e502 | 61 | |
37f9805d | 62 | strlcpy((char *)input, addr, 17); |
3060d4aa | 63 | sys_gettimeofday(&tv); |
bcb7e502 AT |
64 | SIVAL(input, 16, tv.tv_sec); |
65 | SIVAL(input, 20, tv.tv_usec); | |
66 | SIVAL(input, 24, getpid()); | |
67 | ||
ba582f75 | 68 | sum_init(0); |
58c9b4b7 | 69 | sum_update(input, sizeof input); |
bf011fed WD |
70 | sum_end(md4_out); |
71 | ||
72 | base64_encode(md4_out, MD4_SUM_LENGTH, challenge); | |
bcb7e502 AT |
73 | } |
74 | ||
75 | ||
38cab94d WD |
76 | /* Return the secret for a user from the secret file, null terminated. |
77 | * Maximum length is len (not counting the null). */ | |
bcb7e502 AT |
78 | static int get_secret(int module, char *user, char *secret, int len) |
79 | { | |
80 | char *fname = lp_secrets_file(module); | |
d1be2312 | 81 | STRUCT_STAT st; |
38cab94d WD |
82 | int fd, ok = 1; |
83 | char ch, *p; | |
bcb7e502 | 84 | |
38cab94d WD |
85 | if (!fname || !*fname) |
86 | return 0; | |
bcb7e502 | 87 | |
38cab94d WD |
88 | if ((fd = open(fname, O_RDONLY)) < 0) |
89 | return 0; | |
bcb7e502 | 90 | |
d1be2312 | 91 | if (do_stat(fname, &st) == -1) { |
45c49b52 | 92 | rsyserr(FLOG, errno, "stat(%s)", fname); |
d1be2312 | 93 | ok = 0; |
3ca8e68f DD |
94 | } else if (lp_strict_modes(module)) { |
95 | if ((st.st_mode & 06) != 0) { | |
30c041f9 | 96 | rprintf(FLOG, "secrets file must not be other-accessible (see strict modes option)\n"); |
3ca8e68f | 97 | ok = 0; |
351f5e2f | 98 | } else if (MY_UID() == 0 && st.st_uid != 0) { |
30c041f9 | 99 | rprintf(FLOG, "secrets file must be owned by root when running as root (see strict modes)\n"); |
3ca8e68f DD |
100 | ok = 0; |
101 | } | |
d1be2312 DD |
102 | } |
103 | if (!ok) { | |
30c041f9 | 104 | rprintf(FLOG, "continuing without secrets file\n"); |
d1be2312 DD |
105 | close(fd); |
106 | return 0; | |
107 | } | |
108 | ||
38cab94d WD |
109 | if (*user == '#') { |
110 | /* Reject attempt to match a comment. */ | |
111 | close(fd); | |
112 | return 0; | |
113 | } | |
114 | ||
115 | /* Try to find a line that starts with the user name and a ':'. */ | |
116 | p = user; | |
117 | while (1) { | |
118 | if (read(fd, &ch, 1) != 1) { | |
119 | close(fd); | |
120 | return 0; | |
121 | } | |
122 | if (ch == '\n') | |
123 | p = user; | |
124 | else if (p) { | |
125 | if (*p == ch) | |
126 | p++; | |
127 | else if (!*p && ch == ':') | |
128 | break; | |
129 | else | |
130 | p = NULL; | |
bcb7e502 | 131 | } |
bcb7e502 AT |
132 | } |
133 | ||
38cab94d WD |
134 | /* Slurp the secret into the "secret" buffer. */ |
135 | p = secret; | |
136 | while (len > 0) { | |
137 | if (read(fd, p, 1) != 1 || *p == '\n') | |
138 | break; | |
139 | if (*p == '\r') | |
140 | continue; | |
141 | p++; | |
142 | len--; | |
143 | } | |
144 | *p = '\0'; | |
bcb7e502 | 145 | close(fd); |
bcb7e502 | 146 | |
bcb7e502 AT |
147 | return 1; |
148 | } | |
149 | ||
65575e96 AT |
150 | static char *getpassf(char *filename) |
151 | { | |
65575e96 | 152 | STRUCT_STAT st; |
38cab94d WD |
153 | char buffer[512], *p; |
154 | int fd, n, ok = 1; | |
155 | char *envpw = getenv("RSYNC_PASSWORD"); | |
65575e96 | 156 | |
38cab94d WD |
157 | if (!filename) |
158 | return NULL; | |
65575e96 | 159 | |
38cab94d | 160 | if ((fd = open(filename,O_RDONLY)) < 0) { |
4875d6b6 | 161 | rsyserr(FERROR, errno, "could not open password file \"%s\"", |
45c49b52 | 162 | filename); |
38cab94d | 163 | if (envpw) |
18cc8c7e | 164 | rprintf(FERROR, "falling back to RSYNC_PASSWORD environment variable.\n"); |
65575e96 AT |
165 | return NULL; |
166 | } | |
18cc8c7e | 167 | |
65575e96 | 168 | if (do_stat(filename, &st) == -1) { |
45c49b52 | 169 | rsyserr(FERROR, errno, "stat(%s)", filename); |
65575e96 AT |
170 | ok = 0; |
171 | } else if ((st.st_mode & 06) != 0) { | |
172 | rprintf(FERROR,"password file must not be other-accessible\n"); | |
173 | ok = 0; | |
351f5e2f | 174 | } else if (MY_UID() == 0 && st.st_uid != 0) { |
65575e96 AT |
175 | rprintf(FERROR,"password file must be owned by root when running as root\n"); |
176 | ok = 0; | |
177 | } | |
178 | if (!ok) { | |
179 | rprintf(FERROR,"continuing without password file\n"); | |
38cab94d WD |
180 | if (envpw) |
181 | rprintf(FERROR, "using RSYNC_PASSWORD environment variable.\n"); | |
65575e96 AT |
182 | close(fd); |
183 | return NULL; | |
184 | } | |
185 | ||
38cab94d WD |
186 | if (envpw) |
187 | rprintf(FERROR, "RSYNC_PASSWORD environment variable ignored\n"); | |
65575e96 | 188 | |
38cab94d WD |
189 | n = read(fd, buffer, sizeof buffer - 1); |
190 | close(fd); | |
191 | if (n > 0) { | |
192 | buffer[n] = '\0'; | |
193 | if ((p = strtok(buffer, "\n\r")) != NULL) | |
194 | return strdup(p); | |
18cc8c7e | 195 | } |
65575e96 AT |
196 | |
197 | return NULL; | |
198 | } | |
199 | ||
bf011fed WD |
200 | /* Generate an MD4 hash created from the combination of the password |
201 | * and the challenge string and return it base64-encoded. */ | |
6e4fb64e | 202 | static void generate_hash(char *in, char *challenge, char *out) |
bcb7e502 | 203 | { |
5037cf3a | 204 | char buf[MD4_SUM_LENGTH]; |
bcb7e502 | 205 | |
ba582f75 | 206 | sum_init(0); |
bcb7e502 AT |
207 | sum_update(in, strlen(in)); |
208 | sum_update(challenge, strlen(challenge)); | |
209 | sum_end(buf); | |
210 | ||
5037cf3a | 211 | base64_encode(buf, MD4_SUM_LENGTH, out); |
bcb7e502 AT |
212 | } |
213 | ||
18cc8c7e WD |
214 | /* Possibly negotiate authentication with the client. Use "leader" to |
215 | * start off the auth if necessary. | |
216 | * | |
217 | * Return NULL if authentication failed. Return "" if anonymous access. | |
218 | * Otherwise return username. | |
219 | */ | |
5037cf3a WD |
220 | char *auth_server(int f_in, int f_out, int module, char *host, char *addr, |
221 | char *leader) | |
bcb7e502 AT |
222 | { |
223 | char *users = lp_auth_users(module); | |
bf011fed | 224 | char challenge[MD4_SUM_LENGTH*2]; |
d999d312 | 225 | char line[BIGPATHBUFLEN]; |
5037cf3a WD |
226 | char secret[512]; |
227 | char pass2[MD4_SUM_LENGTH*2]; | |
228 | char *tok, *pass; | |
bcb7e502 AT |
229 | |
230 | /* if no auth list then allow anyone in! */ | |
58c9b4b7 WD |
231 | if (!users || !*users) |
232 | return ""; | |
bcb7e502 AT |
233 | |
234 | gen_challenge(addr, challenge); | |
18cc8c7e | 235 | |
bf011fed | 236 | io_printf(f_out, "%s%s\n", leader, challenge); |
bcb7e502 | 237 | |
5037cf3a WD |
238 | if (!read_line(f_in, line, sizeof line - 1) |
239 | || (pass = strchr(line, ' ')) == NULL) { | |
240 | rprintf(FLOG, "auth failed on module %s from %s (%s): " | |
241 | "invalid challenge response\n", | |
242 | lp_name(module), host, addr); | |
d0d56395 | 243 | return NULL; |
5037cf3a WD |
244 | } |
245 | *pass++ = '\0'; | |
18cc8c7e | 246 | |
5037cf3a WD |
247 | if (!(users = strdup(users))) |
248 | out_of_memory("auth_server"); | |
c8e78d87 | 249 | |
5037cf3a WD |
250 | for (tok = strtok(users, " ,\t"); tok; tok = strtok(NULL, " ,\t")) { |
251 | if (wildmatch(tok, line)) | |
58c9b4b7 | 252 | break; |
c8e78d87 AT |
253 | } |
254 | free(users); | |
255 | ||
5037cf3a WD |
256 | if (!tok) { |
257 | rprintf(FLOG, "auth failed on module %s from %s (%s): " | |
258 | "unauthorized user\n", | |
259 | lp_name(module), host, addr); | |
d0d56395 | 260 | return NULL; |
5037cf3a | 261 | } |
18cc8c7e | 262 | |
58c9b4b7 | 263 | memset(secret, 0, sizeof secret); |
5037cf3a | 264 | if (!get_secret(module, line, secret, sizeof secret - 1)) { |
58c9b4b7 | 265 | memset(secret, 0, sizeof secret); |
5037cf3a WD |
266 | rprintf(FLOG, "auth failed on module %s from %s (%s): " |
267 | "missing secret for user \"%s\"\n", | |
268 | lp_name(module), host, addr, line); | |
d0d56395 | 269 | return NULL; |
bcb7e502 AT |
270 | } |
271 | ||
bf011fed | 272 | generate_hash(secret, challenge, pass2); |
58c9b4b7 | 273 | memset(secret, 0, sizeof secret); |
18cc8c7e | 274 | |
5037cf3a WD |
275 | if (strcmp(pass, pass2) != 0) { |
276 | rprintf(FLOG, "auth failed on module %s from %s (%s): " | |
277 | "password mismatch\n", | |
278 | lp_name(module), host, addr); | |
279 | return NULL; | |
280 | } | |
d0d56395 | 281 | |
5037cf3a | 282 | return strdup(line); |
bcb7e502 AT |
283 | } |
284 | ||
285 | ||
286 | void auth_client(int fd, char *user, char *challenge) | |
287 | { | |
288 | char *pass; | |
5037cf3a | 289 | char pass2[MD4_SUM_LENGTH*2]; |
bcb7e502 | 290 | |
ef383c0d | 291 | if (!user || !*user) |
4b2f6a7c | 292 | user = "nobody"; |
bcb7e502 | 293 | |
58c9b4b7 WD |
294 | if (!(pass = getpassf(password_file)) |
295 | && !(pass = getenv("RSYNC_PASSWORD"))) { | |
64bd7568 | 296 | /* XXX: cyeoh says that getpass is deprecated, because |
908f5a9f MP |
297 | * it may return a truncated password on some systems, |
298 | * and it is not in the LSB. | |
299 | * | |
300 | * Andrew Klein says that getpassphrase() is present | |
301 | * on Solaris and reads up to 256 characters. | |
302 | * | |
303 | * OpenBSD has a readpassphrase() that might be more suitable. | |
304 | */ | |
bcb7e502 AT |
305 | pass = getpass("Password: "); |
306 | } | |
307 | ||
38cab94d | 308 | if (!pass) |
bcb7e502 | 309 | pass = ""; |
bcb7e502 AT |
310 | |
311 | generate_hash(pass, challenge, pass2); | |
bcb7e502 AT |
312 | io_printf(fd, "%s %s\n", user, pass2); |
313 | } |