Commit | Line | Data |
---|---|---|
0f78b815 WD |
1 | /* |
2 | * Support rsync daemon authentication. | |
3 | * | |
4 | * Copyright (C) 1998-2000 Andrew Tridgell | |
5 | * Copyright (C) 2002, 2004, 2005, 2006 Wayne Davison | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License as published by | |
9 | * the Free Software Foundation; either version 2 of the License, or | |
10 | * (at your option) any later version. | |
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 WD |
17 | * You should have received a copy of the GNU General Public License along |
18 | * with this program; if not, write to the Free Software Foundation, Inc., | |
19 | * 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. | |
0f78b815 | 20 | */ |
18cc8c7e | 21 | |
31593dd6 AT |
22 | #include "rsync.h" |
23 | ||
38cab94d | 24 | extern char *password_file; |
38cab94d | 25 | |
bcb7e502 AT |
26 | /*************************************************************************** |
27 | encode a buffer using base64 - simple and slow algorithm. null terminates | |
28 | the result. | |
29 | ***************************************************************************/ | |
4a19c3b2 | 30 | void base64_encode(const char *buf, int len, char *out, int pad) |
bcb7e502 AT |
31 | { |
32 | char *b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; | |
33 | int bit_offset, byte_offset, idx, i; | |
4a19c3b2 | 34 | const uchar *d = (const uchar *)buf; |
bcb7e502 AT |
35 | int bytes = (len*8 + 5)/6; |
36 | ||
57385128 | 37 | for (i = 0; i < bytes; i++) { |
bcb7e502 AT |
38 | byte_offset = (i*6)/8; |
39 | bit_offset = (i*6)%8; | |
40 | if (bit_offset < 3) { | |
41 | idx = (d[byte_offset] >> (2-bit_offset)) & 0x3F; | |
42 | } else { | |
43 | idx = (d[byte_offset] << (bit_offset-2)) & 0x3F; | |
44 | if (byte_offset+1 < len) { | |
45 | idx |= (d[byte_offset+1] >> (8-(bit_offset-2))); | |
46 | } | |
47 | } | |
48 | out[i] = b64[idx]; | |
49 | } | |
293def60 WD |
50 | |
51 | while (pad && (i % 4)) | |
52 | out[i++] = '='; | |
53 | ||
54 | out[i] = '\0'; | |
bcb7e502 AT |
55 | } |
56 | ||
bf011fed | 57 | /* Generate a challenge buffer and return it base64-encoded. */ |
4a19c3b2 | 58 | static void gen_challenge(const char *addr, char *challenge) |
bcb7e502 AT |
59 | { |
60 | char input[32]; | |
bf011fed | 61 | char md4_out[MD4_SUM_LENGTH]; |
bcb7e502 AT |
62 | struct timeval tv; |
63 | ||
58c9b4b7 | 64 | memset(input, 0, sizeof input); |
bcb7e502 | 65 | |
4a19c3b2 | 66 | strlcpy(input, addr, 17); |
3060d4aa | 67 | sys_gettimeofday(&tv); |
bcb7e502 AT |
68 | SIVAL(input, 16, tv.tv_sec); |
69 | SIVAL(input, 20, tv.tv_usec); | |
70 | SIVAL(input, 24, getpid()); | |
71 | ||
ba582f75 | 72 | sum_init(0); |
58c9b4b7 | 73 | sum_update(input, sizeof input); |
bf011fed WD |
74 | sum_end(md4_out); |
75 | ||
293def60 | 76 | base64_encode(md4_out, MD4_SUM_LENGTH, challenge, 0); |
bcb7e502 AT |
77 | } |
78 | ||
79 | ||
38cab94d WD |
80 | /* Return the secret for a user from the secret file, null terminated. |
81 | * Maximum length is len (not counting the null). */ | |
4a19c3b2 | 82 | static int get_secret(int module, const char *user, char *secret, int len) |
bcb7e502 | 83 | { |
4a19c3b2 | 84 | const char *fname = lp_secrets_file(module); |
d1be2312 | 85 | STRUCT_STAT st; |
38cab94d | 86 | int fd, ok = 1; |
4a19c3b2 WD |
87 | const char *p; |
88 | char ch, *s; | |
bcb7e502 | 89 | |
38cab94d WD |
90 | if (!fname || !*fname) |
91 | return 0; | |
bcb7e502 | 92 | |
38cab94d WD |
93 | if ((fd = open(fname, O_RDONLY)) < 0) |
94 | return 0; | |
bcb7e502 | 95 | |
d1be2312 | 96 | if (do_stat(fname, &st) == -1) { |
45c49b52 | 97 | rsyserr(FLOG, errno, "stat(%s)", fname); |
d1be2312 | 98 | ok = 0; |
3ca8e68f DD |
99 | } else if (lp_strict_modes(module)) { |
100 | if ((st.st_mode & 06) != 0) { | |
30c041f9 | 101 | rprintf(FLOG, "secrets file must not be other-accessible (see strict modes option)\n"); |
3ca8e68f | 102 | ok = 0; |
351f5e2f | 103 | } else if (MY_UID() == 0 && st.st_uid != 0) { |
30c041f9 | 104 | rprintf(FLOG, "secrets file must be owned by root when running as root (see strict modes)\n"); |
3ca8e68f DD |
105 | ok = 0; |
106 | } | |
d1be2312 DD |
107 | } |
108 | if (!ok) { | |
30c041f9 | 109 | rprintf(FLOG, "continuing without secrets file\n"); |
d1be2312 DD |
110 | close(fd); |
111 | return 0; | |
112 | } | |
113 | ||
38cab94d WD |
114 | if (*user == '#') { |
115 | /* Reject attempt to match a comment. */ | |
116 | close(fd); | |
117 | return 0; | |
118 | } | |
119 | ||
120 | /* Try to find a line that starts with the user name and a ':'. */ | |
121 | p = user; | |
122 | while (1) { | |
123 | if (read(fd, &ch, 1) != 1) { | |
124 | close(fd); | |
125 | return 0; | |
126 | } | |
127 | if (ch == '\n') | |
128 | p = user; | |
129 | else if (p) { | |
130 | if (*p == ch) | |
131 | p++; | |
132 | else if (!*p && ch == ':') | |
133 | break; | |
134 | else | |
135 | p = NULL; | |
bcb7e502 | 136 | } |
bcb7e502 AT |
137 | } |
138 | ||
38cab94d | 139 | /* Slurp the secret into the "secret" buffer. */ |
4a19c3b2 | 140 | s = secret; |
38cab94d | 141 | while (len > 0) { |
4a19c3b2 | 142 | if (read(fd, s, 1) != 1 || *s == '\n') |
38cab94d | 143 | break; |
4a19c3b2 | 144 | if (*s == '\r') |
38cab94d | 145 | continue; |
4a19c3b2 | 146 | s++; |
38cab94d WD |
147 | len--; |
148 | } | |
4a19c3b2 | 149 | *s = '\0'; |
bcb7e502 | 150 | close(fd); |
bcb7e502 | 151 | |
bcb7e502 AT |
152 | return 1; |
153 | } | |
154 | ||
4a19c3b2 | 155 | static const char *getpassf(const char *filename) |
65575e96 | 156 | { |
65575e96 | 157 | STRUCT_STAT st; |
38cab94d WD |
158 | char buffer[512], *p; |
159 | int fd, n, ok = 1; | |
4a19c3b2 | 160 | const char *envpw = getenv("RSYNC_PASSWORD"); |
65575e96 | 161 | |
38cab94d WD |
162 | if (!filename) |
163 | return NULL; | |
65575e96 | 164 | |
38cab94d | 165 | if ((fd = open(filename,O_RDONLY)) < 0) { |
4875d6b6 | 166 | rsyserr(FERROR, errno, "could not open password file \"%s\"", |
45c49b52 | 167 | filename); |
38cab94d | 168 | if (envpw) |
18cc8c7e | 169 | rprintf(FERROR, "falling back to RSYNC_PASSWORD environment variable.\n"); |
65575e96 AT |
170 | return NULL; |
171 | } | |
18cc8c7e | 172 | |
65575e96 | 173 | if (do_stat(filename, &st) == -1) { |
45c49b52 | 174 | rsyserr(FERROR, errno, "stat(%s)", filename); |
65575e96 AT |
175 | ok = 0; |
176 | } else if ((st.st_mode & 06) != 0) { | |
177 | rprintf(FERROR,"password file must not be other-accessible\n"); | |
178 | ok = 0; | |
351f5e2f | 179 | } else if (MY_UID() == 0 && st.st_uid != 0) { |
65575e96 AT |
180 | rprintf(FERROR,"password file must be owned by root when running as root\n"); |
181 | ok = 0; | |
182 | } | |
183 | if (!ok) { | |
184 | rprintf(FERROR,"continuing without password file\n"); | |
38cab94d WD |
185 | if (envpw) |
186 | rprintf(FERROR, "using RSYNC_PASSWORD environment variable.\n"); | |
65575e96 AT |
187 | close(fd); |
188 | return NULL; | |
189 | } | |
190 | ||
38cab94d WD |
191 | if (envpw) |
192 | rprintf(FERROR, "RSYNC_PASSWORD environment variable ignored\n"); | |
65575e96 | 193 | |
38cab94d WD |
194 | n = read(fd, buffer, sizeof buffer - 1); |
195 | close(fd); | |
196 | if (n > 0) { | |
197 | buffer[n] = '\0'; | |
198 | if ((p = strtok(buffer, "\n\r")) != NULL) | |
199 | return strdup(p); | |
18cc8c7e | 200 | } |
65575e96 AT |
201 | |
202 | return NULL; | |
203 | } | |
204 | ||
bf011fed WD |
205 | /* Generate an MD4 hash created from the combination of the password |
206 | * and the challenge string and return it base64-encoded. */ | |
4a19c3b2 | 207 | static void generate_hash(const char *in, const char *challenge, char *out) |
bcb7e502 | 208 | { |
5037cf3a | 209 | char buf[MD4_SUM_LENGTH]; |
bcb7e502 | 210 | |
ba582f75 | 211 | sum_init(0); |
bcb7e502 AT |
212 | sum_update(in, strlen(in)); |
213 | sum_update(challenge, strlen(challenge)); | |
214 | sum_end(buf); | |
215 | ||
293def60 | 216 | base64_encode(buf, MD4_SUM_LENGTH, out, 0); |
bcb7e502 AT |
217 | } |
218 | ||
18cc8c7e WD |
219 | /* Possibly negotiate authentication with the client. Use "leader" to |
220 | * start off the auth if necessary. | |
221 | * | |
222 | * Return NULL if authentication failed. Return "" if anonymous access. | |
223 | * Otherwise return username. | |
224 | */ | |
4a19c3b2 WD |
225 | char *auth_server(int f_in, int f_out, int module, const char *host, |
226 | const char *addr, const char *leader) | |
bcb7e502 AT |
227 | { |
228 | char *users = lp_auth_users(module); | |
bf011fed | 229 | char challenge[MD4_SUM_LENGTH*2]; |
d999d312 | 230 | char line[BIGPATHBUFLEN]; |
5037cf3a WD |
231 | char secret[512]; |
232 | char pass2[MD4_SUM_LENGTH*2]; | |
233 | char *tok, *pass; | |
bcb7e502 AT |
234 | |
235 | /* if no auth list then allow anyone in! */ | |
58c9b4b7 WD |
236 | if (!users || !*users) |
237 | return ""; | |
bcb7e502 AT |
238 | |
239 | gen_challenge(addr, challenge); | |
18cc8c7e | 240 | |
bf011fed | 241 | io_printf(f_out, "%s%s\n", leader, challenge); |
bcb7e502 | 242 | |
5037cf3a WD |
243 | if (!read_line(f_in, line, sizeof line - 1) |
244 | || (pass = strchr(line, ' ')) == NULL) { | |
245 | rprintf(FLOG, "auth failed on module %s from %s (%s): " | |
246 | "invalid challenge response\n", | |
247 | lp_name(module), host, addr); | |
d0d56395 | 248 | return NULL; |
5037cf3a WD |
249 | } |
250 | *pass++ = '\0'; | |
18cc8c7e | 251 | |
5037cf3a WD |
252 | if (!(users = strdup(users))) |
253 | out_of_memory("auth_server"); | |
c8e78d87 | 254 | |
5037cf3a WD |
255 | for (tok = strtok(users, " ,\t"); tok; tok = strtok(NULL, " ,\t")) { |
256 | if (wildmatch(tok, line)) | |
58c9b4b7 | 257 | break; |
c8e78d87 AT |
258 | } |
259 | free(users); | |
260 | ||
5037cf3a WD |
261 | if (!tok) { |
262 | rprintf(FLOG, "auth failed on module %s from %s (%s): " | |
263 | "unauthorized user\n", | |
264 | lp_name(module), host, addr); | |
d0d56395 | 265 | return NULL; |
5037cf3a | 266 | } |
18cc8c7e | 267 | |
58c9b4b7 | 268 | memset(secret, 0, sizeof secret); |
5037cf3a | 269 | if (!get_secret(module, line, secret, sizeof secret - 1)) { |
58c9b4b7 | 270 | memset(secret, 0, sizeof secret); |
5037cf3a WD |
271 | rprintf(FLOG, "auth failed on module %s from %s (%s): " |
272 | "missing secret for user \"%s\"\n", | |
273 | lp_name(module), host, addr, line); | |
d0d56395 | 274 | return NULL; |
bcb7e502 AT |
275 | } |
276 | ||
bf011fed | 277 | generate_hash(secret, challenge, pass2); |
58c9b4b7 | 278 | memset(secret, 0, sizeof secret); |
18cc8c7e | 279 | |
5037cf3a WD |
280 | if (strcmp(pass, pass2) != 0) { |
281 | rprintf(FLOG, "auth failed on module %s from %s (%s): " | |
282 | "password mismatch\n", | |
283 | lp_name(module), host, addr); | |
284 | return NULL; | |
285 | } | |
d0d56395 | 286 | |
5037cf3a | 287 | return strdup(line); |
bcb7e502 AT |
288 | } |
289 | ||
4a19c3b2 | 290 | void auth_client(int fd, const char *user, const char *challenge) |
bcb7e502 | 291 | { |
4a19c3b2 | 292 | const char *pass; |
5037cf3a | 293 | char pass2[MD4_SUM_LENGTH*2]; |
bcb7e502 | 294 | |
ef383c0d | 295 | if (!user || !*user) |
4b2f6a7c | 296 | user = "nobody"; |
bcb7e502 | 297 | |
58c9b4b7 WD |
298 | if (!(pass = getpassf(password_file)) |
299 | && !(pass = getenv("RSYNC_PASSWORD"))) { | |
64bd7568 | 300 | /* XXX: cyeoh says that getpass is deprecated, because |
908f5a9f MP |
301 | * it may return a truncated password on some systems, |
302 | * and it is not in the LSB. | |
303 | * | |
304 | * Andrew Klein says that getpassphrase() is present | |
305 | * on Solaris and reads up to 256 characters. | |
306 | * | |
307 | * OpenBSD has a readpassphrase() that might be more suitable. | |
308 | */ | |
bcb7e502 AT |
309 | pass = getpass("Password: "); |
310 | } | |
311 | ||
38cab94d | 312 | if (!pass) |
bcb7e502 | 313 | pass = ""; |
bcb7e502 AT |
314 | |
315 | generate_hash(pass, challenge, pass2); | |
bcb7e502 AT |
316 | io_printf(fd, "%s %s\n", user, pass2); |
317 | } |