Commit | Line | Data |
---|---|---|
0f78b815 WD |
1 | /* |
2 | * Support rsync daemon authentication. | |
3 | * | |
4 | * Copyright (C) 1998-2000 Andrew Tridgell | |
ba2133d6 | 5 | * Copyright (C) 2002-2007 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 AT |
21 | #include "rsync.h" |
22 | ||
38cab94d | 23 | extern char *password_file; |
c9b16cda | 24 | extern int log_got_error; |
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]; | |
a0456b9c | 61 | char digest[MAX_DIGEST_LEN]; |
bcb7e502 | 62 | struct timeval tv; |
a0456b9c | 63 | int len; |
bcb7e502 | 64 | |
58c9b4b7 | 65 | memset(input, 0, sizeof input); |
bcb7e502 | 66 | |
4a19c3b2 | 67 | strlcpy(input, addr, 17); |
3060d4aa | 68 | sys_gettimeofday(&tv); |
bcb7e502 AT |
69 | SIVAL(input, 16, tv.tv_sec); |
70 | SIVAL(input, 20, tv.tv_usec); | |
71 | SIVAL(input, 24, getpid()); | |
72 | ||
ba582f75 | 73 | sum_init(0); |
58c9b4b7 | 74 | sum_update(input, sizeof input); |
a0456b9c | 75 | len = sum_end(digest); |
bf011fed | 76 | |
a0456b9c | 77 | base64_encode(digest, len, challenge, 0); |
bcb7e502 AT |
78 | } |
79 | ||
80 | ||
38cab94d WD |
81 | /* Return the secret for a user from the secret file, null terminated. |
82 | * Maximum length is len (not counting the null). */ | |
4a19c3b2 | 83 | static int get_secret(int module, const char *user, char *secret, int len) |
bcb7e502 | 84 | { |
4a19c3b2 | 85 | const char *fname = lp_secrets_file(module); |
d1be2312 | 86 | STRUCT_STAT st; |
38cab94d | 87 | int fd, ok = 1; |
4a19c3b2 WD |
88 | const char *p; |
89 | char ch, *s; | |
bcb7e502 | 90 | |
38cab94d WD |
91 | if (!fname || !*fname) |
92 | return 0; | |
bcb7e502 | 93 | |
38cab94d WD |
94 | if ((fd = open(fname, O_RDONLY)) < 0) |
95 | return 0; | |
bcb7e502 | 96 | |
d1be2312 | 97 | if (do_stat(fname, &st) == -1) { |
45c49b52 | 98 | rsyserr(FLOG, errno, "stat(%s)", fname); |
d1be2312 | 99 | ok = 0; |
3ca8e68f DD |
100 | } else if (lp_strict_modes(module)) { |
101 | if ((st.st_mode & 06) != 0) { | |
30c041f9 | 102 | rprintf(FLOG, "secrets file must not be other-accessible (see strict modes option)\n"); |
3ca8e68f | 103 | ok = 0; |
351f5e2f | 104 | } else if (MY_UID() == 0 && st.st_uid != 0) { |
30c041f9 | 105 | rprintf(FLOG, "secrets file must be owned by root when running as root (see strict modes)\n"); |
3ca8e68f DD |
106 | ok = 0; |
107 | } | |
d1be2312 DD |
108 | } |
109 | if (!ok) { | |
30c041f9 | 110 | rprintf(FLOG, "continuing without secrets file\n"); |
d1be2312 DD |
111 | close(fd); |
112 | return 0; | |
113 | } | |
114 | ||
38cab94d WD |
115 | if (*user == '#') { |
116 | /* Reject attempt to match a comment. */ | |
117 | close(fd); | |
118 | return 0; | |
119 | } | |
120 | ||
121 | /* Try to find a line that starts with the user name and a ':'. */ | |
122 | p = user; | |
123 | while (1) { | |
124 | if (read(fd, &ch, 1) != 1) { | |
125 | close(fd); | |
126 | return 0; | |
127 | } | |
128 | if (ch == '\n') | |
129 | p = user; | |
130 | else if (p) { | |
131 | if (*p == ch) | |
132 | p++; | |
133 | else if (!*p && ch == ':') | |
134 | break; | |
135 | else | |
136 | p = NULL; | |
bcb7e502 | 137 | } |
bcb7e502 AT |
138 | } |
139 | ||
38cab94d | 140 | /* Slurp the secret into the "secret" buffer. */ |
4a19c3b2 | 141 | s = secret; |
38cab94d | 142 | while (len > 0) { |
4a19c3b2 | 143 | if (read(fd, s, 1) != 1 || *s == '\n') |
38cab94d | 144 | break; |
4a19c3b2 | 145 | if (*s == '\r') |
38cab94d | 146 | continue; |
4a19c3b2 | 147 | s++; |
38cab94d WD |
148 | len--; |
149 | } | |
4a19c3b2 | 150 | *s = '\0'; |
bcb7e502 | 151 | close(fd); |
bcb7e502 | 152 | |
bcb7e502 AT |
153 | return 1; |
154 | } | |
155 | ||
4a19c3b2 | 156 | static const char *getpassf(const char *filename) |
65575e96 | 157 | { |
65575e96 | 158 | STRUCT_STAT st; |
38cab94d WD |
159 | char buffer[512], *p; |
160 | int fd, n, ok = 1; | |
4a19c3b2 | 161 | const char *envpw = getenv("RSYNC_PASSWORD"); |
65575e96 | 162 | |
38cab94d WD |
163 | if (!filename) |
164 | return NULL; | |
65575e96 | 165 | |
38cab94d | 166 | if ((fd = open(filename,O_RDONLY)) < 0) { |
4875d6b6 | 167 | rsyserr(FERROR, errno, "could not open password file \"%s\"", |
45c49b52 | 168 | filename); |
38cab94d | 169 | if (envpw) |
3f655ca0 | 170 | rprintf(FINFO, "falling back to RSYNC_PASSWORD environment variable.\n"); |
65575e96 AT |
171 | return NULL; |
172 | } | |
18cc8c7e | 173 | |
65575e96 | 174 | if (do_stat(filename, &st) == -1) { |
45c49b52 | 175 | rsyserr(FERROR, errno, "stat(%s)", filename); |
65575e96 AT |
176 | ok = 0; |
177 | } else if ((st.st_mode & 06) != 0) { | |
3f655ca0 | 178 | rprintf(FERROR, "password file must not be other-accessible\n"); |
65575e96 | 179 | ok = 0; |
351f5e2f | 180 | } else if (MY_UID() == 0 && st.st_uid != 0) { |
3f655ca0 | 181 | rprintf(FERROR, "password file must be owned by root when running as root\n"); |
65575e96 AT |
182 | ok = 0; |
183 | } | |
184 | if (!ok) { | |
65575e96 | 185 | close(fd); |
3f655ca0 WD |
186 | rprintf(FERROR, "continuing without password file\n"); |
187 | if (envpw) | |
188 | rprintf(FINFO, "falling back to RSYNC_PASSWORD environment variable.\n"); | |
65575e96 AT |
189 | return NULL; |
190 | } | |
191 | ||
38cab94d WD |
192 | n = read(fd, buffer, sizeof buffer - 1); |
193 | close(fd); | |
194 | if (n > 0) { | |
195 | buffer[n] = '\0'; | |
196 | if ((p = strtok(buffer, "\n\r")) != NULL) | |
197 | return strdup(p); | |
18cc8c7e | 198 | } |
65575e96 AT |
199 | |
200 | return NULL; | |
201 | } | |
202 | ||
bf011fed WD |
203 | /* Generate an MD4 hash created from the combination of the password |
204 | * and the challenge string and return it base64-encoded. */ | |
4a19c3b2 | 205 | static void generate_hash(const char *in, const char *challenge, char *out) |
bcb7e502 | 206 | { |
a0456b9c WD |
207 | char buf[MAX_DIGEST_LEN]; |
208 | int len; | |
bcb7e502 | 209 | |
ba582f75 | 210 | sum_init(0); |
bcb7e502 AT |
211 | sum_update(in, strlen(in)); |
212 | sum_update(challenge, strlen(challenge)); | |
a0456b9c | 213 | len = sum_end(buf); |
bcb7e502 | 214 | |
a0456b9c | 215 | base64_encode(buf, len, out, 0); |
bcb7e502 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]; |
5037cf3a | 230 | char secret[512]; |
a0456b9c | 231 | char pass2[MAX_DIGEST_LEN*2]; |
5037cf3a | 232 | char *tok, *pass; |
bcb7e502 AT |
233 | |
234 | /* if no auth list then allow anyone in! */ | |
58c9b4b7 WD |
235 | if (!users || !*users) |
236 | return ""; | |
bcb7e502 AT |
237 | |
238 | gen_challenge(addr, challenge); | |
18cc8c7e | 239 | |
bf011fed | 240 | io_printf(f_out, "%s%s\n", leader, challenge); |
bcb7e502 | 241 | |
f74a3d81 | 242 | if (!read_line_old(f_in, line, sizeof line) |
5037cf3a WD |
243 | || (pass = strchr(line, ' ')) == NULL) { |
244 | rprintf(FLOG, "auth failed on module %s from %s (%s): " | |
245 | "invalid challenge response\n", | |
246 | lp_name(module), host, addr); | |
d0d56395 | 247 | return NULL; |
5037cf3a WD |
248 | } |
249 | *pass++ = '\0'; | |
18cc8c7e | 250 | |
5037cf3a WD |
251 | if (!(users = strdup(users))) |
252 | out_of_memory("auth_server"); | |
c8e78d87 | 253 | |
5037cf3a WD |
254 | for (tok = strtok(users, " ,\t"); tok; tok = strtok(NULL, " ,\t")) { |
255 | if (wildmatch(tok, line)) | |
58c9b4b7 | 256 | break; |
c8e78d87 AT |
257 | } |
258 | free(users); | |
259 | ||
5037cf3a WD |
260 | if (!tok) { |
261 | rprintf(FLOG, "auth failed on module %s from %s (%s): " | |
262 | "unauthorized user\n", | |
263 | lp_name(module), host, addr); | |
d0d56395 | 264 | return NULL; |
5037cf3a | 265 | } |
18cc8c7e | 266 | |
58c9b4b7 | 267 | memset(secret, 0, sizeof secret); |
5037cf3a | 268 | if (!get_secret(module, line, secret, sizeof secret - 1)) { |
58c9b4b7 | 269 | memset(secret, 0, sizeof secret); |
5037cf3a WD |
270 | rprintf(FLOG, "auth failed on module %s from %s (%s): " |
271 | "missing secret for user \"%s\"\n", | |
272 | lp_name(module), host, addr, line); | |
d0d56395 | 273 | return NULL; |
bcb7e502 AT |
274 | } |
275 | ||
bf011fed | 276 | generate_hash(secret, challenge, pass2); |
58c9b4b7 | 277 | memset(secret, 0, sizeof secret); |
18cc8c7e | 278 | |
5037cf3a WD |
279 | if (strcmp(pass, pass2) != 0) { |
280 | rprintf(FLOG, "auth failed on module %s from %s (%s): " | |
281 | "password mismatch\n", | |
282 | lp_name(module), host, addr); | |
283 | return NULL; | |
284 | } | |
d0d56395 | 285 | |
5037cf3a | 286 | return strdup(line); |
bcb7e502 AT |
287 | } |
288 | ||
4a19c3b2 | 289 | void auth_client(int fd, const char *user, const char *challenge) |
bcb7e502 | 290 | { |
4a19c3b2 | 291 | const char *pass; |
a0456b9c | 292 | char pass2[MAX_DIGEST_LEN*2]; |
bcb7e502 | 293 | |
ef383c0d | 294 | if (!user || !*user) |
4b2f6a7c | 295 | user = "nobody"; |
bcb7e502 | 296 | |
58c9b4b7 WD |
297 | if (!(pass = getpassf(password_file)) |
298 | && !(pass = getenv("RSYNC_PASSWORD"))) { | |
64bd7568 | 299 | /* XXX: cyeoh says that getpass is deprecated, because |
908f5a9f MP |
300 | * it may return a truncated password on some systems, |
301 | * and it is not in the LSB. | |
302 | * | |
303 | * Andrew Klein says that getpassphrase() is present | |
304 | * on Solaris and reads up to 256 characters. | |
305 | * | |
306 | * OpenBSD has a readpassphrase() that might be more suitable. | |
307 | */ | |
bcb7e502 AT |
308 | pass = getpass("Password: "); |
309 | } | |
310 | ||
c9b16cda WD |
311 | /* Any errors output during password handling aren't transfer errors. */ |
312 | log_got_error = 0; | |
313 | ||
38cab94d | 314 | if (!pass) |
bcb7e502 | 315 | pass = ""; |
bcb7e502 AT |
316 | |
317 | generate_hash(pass, challenge, pass2); | |
bcb7e502 AT |
318 | io_printf(fd, "%s %s\n", user, pass2); |
319 | } |