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 WD |
23 | extern char *password_file; |
24 | extern int am_root; | |
25 | ||
bcb7e502 AT |
26 | /*************************************************************************** |
27 | encode a buffer using base64 - simple and slow algorithm. null terminates | |
28 | the result. | |
29 | ***************************************************************************/ | |
57385128 | 30 | void base64_encode(char *buf, int len, char *out) |
bcb7e502 AT |
31 | { |
32 | char *b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; | |
33 | int bit_offset, byte_offset, idx, i; | |
34 | unsigned char *d = (unsigned char *)buf; | |
bcb7e502 AT |
35 | int bytes = (len*8 + 5)/6; |
36 | ||
37 | memset(out, 0, bytes+1); | |
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 | } | |
52 | } | |
53 | ||
bf011fed | 54 | /* Generate a challenge buffer and return it base64-encoded. */ |
bcb7e502 AT |
55 | static void gen_challenge(char *addr, char *challenge) |
56 | { | |
57 | char input[32]; | |
bf011fed | 58 | char md4_out[MD4_SUM_LENGTH]; |
bcb7e502 AT |
59 | struct timeval tv; |
60 | ||
58c9b4b7 | 61 | memset(input, 0, sizeof input); |
bcb7e502 | 62 | |
37f9805d | 63 | strlcpy((char *)input, addr, 17); |
3060d4aa | 64 | sys_gettimeofday(&tv); |
bcb7e502 AT |
65 | SIVAL(input, 16, tv.tv_sec); |
66 | SIVAL(input, 20, tv.tv_usec); | |
67 | SIVAL(input, 24, getpid()); | |
68 | ||
ba582f75 | 69 | sum_init(0); |
58c9b4b7 | 70 | sum_update(input, sizeof input); |
bf011fed WD |
71 | sum_end(md4_out); |
72 | ||
73 | base64_encode(md4_out, MD4_SUM_LENGTH, challenge); | |
bcb7e502 AT |
74 | } |
75 | ||
76 | ||
38cab94d WD |
77 | /* Return the secret for a user from the secret file, null terminated. |
78 | * Maximum length is len (not counting the null). */ | |
bcb7e502 AT |
79 | static int get_secret(int module, char *user, char *secret, int len) |
80 | { | |
81 | char *fname = lp_secrets_file(module); | |
d1be2312 | 82 | STRUCT_STAT st; |
38cab94d WD |
83 | int fd, ok = 1; |
84 | char ch, *p; | |
bcb7e502 | 85 | |
38cab94d WD |
86 | if (!fname || !*fname) |
87 | return 0; | |
bcb7e502 | 88 | |
38cab94d WD |
89 | if ((fd = open(fname, O_RDONLY)) < 0) |
90 | return 0; | |
bcb7e502 | 91 | |
d1be2312 | 92 | if (do_stat(fname, &st) == -1) { |
45c49b52 | 93 | rsyserr(FLOG, errno, "stat(%s)", fname); |
d1be2312 | 94 | ok = 0; |
3ca8e68f DD |
95 | } else if (lp_strict_modes(module)) { |
96 | if ((st.st_mode & 06) != 0) { | |
30c041f9 | 97 | rprintf(FLOG, "secrets file must not be other-accessible (see strict modes option)\n"); |
3ca8e68f DD |
98 | ok = 0; |
99 | } else if (am_root && (st.st_uid != 0)) { | |
30c041f9 | 100 | rprintf(FLOG, "secrets file must be owned by root when running as root (see strict modes)\n"); |
3ca8e68f DD |
101 | ok = 0; |
102 | } | |
d1be2312 DD |
103 | } |
104 | if (!ok) { | |
30c041f9 | 105 | rprintf(FLOG, "continuing without secrets file\n"); |
d1be2312 DD |
106 | close(fd); |
107 | return 0; | |
108 | } | |
109 | ||
38cab94d WD |
110 | if (*user == '#') { |
111 | /* Reject attempt to match a comment. */ | |
112 | close(fd); | |
113 | return 0; | |
114 | } | |
115 | ||
116 | /* Try to find a line that starts with the user name and a ':'. */ | |
117 | p = user; | |
118 | while (1) { | |
119 | if (read(fd, &ch, 1) != 1) { | |
120 | close(fd); | |
121 | return 0; | |
122 | } | |
123 | if (ch == '\n') | |
124 | p = user; | |
125 | else if (p) { | |
126 | if (*p == ch) | |
127 | p++; | |
128 | else if (!*p && ch == ':') | |
129 | break; | |
130 | else | |
131 | p = NULL; | |
bcb7e502 | 132 | } |
bcb7e502 AT |
133 | } |
134 | ||
38cab94d WD |
135 | /* Slurp the secret into the "secret" buffer. */ |
136 | p = secret; | |
137 | while (len > 0) { | |
138 | if (read(fd, p, 1) != 1 || *p == '\n') | |
139 | break; | |
140 | if (*p == '\r') | |
141 | continue; | |
142 | p++; | |
143 | len--; | |
144 | } | |
145 | *p = '\0'; | |
bcb7e502 | 146 | close(fd); |
bcb7e502 | 147 | |
bcb7e502 AT |
148 | return 1; |
149 | } | |
150 | ||
65575e96 AT |
151 | static char *getpassf(char *filename) |
152 | { | |
65575e96 | 153 | STRUCT_STAT st; |
38cab94d WD |
154 | char buffer[512], *p; |
155 | int fd, n, ok = 1; | |
156 | char *envpw = getenv("RSYNC_PASSWORD"); | |
65575e96 | 157 | |
38cab94d WD |
158 | if (!filename) |
159 | return NULL; | |
65575e96 | 160 | |
38cab94d | 161 | if ((fd = open(filename,O_RDONLY)) < 0) { |
4875d6b6 | 162 | rsyserr(FERROR, errno, "could not open password file \"%s\"", |
45c49b52 | 163 | filename); |
38cab94d | 164 | if (envpw) |
18cc8c7e | 165 | rprintf(FERROR, "falling back to RSYNC_PASSWORD environment variable.\n"); |
65575e96 AT |
166 | return NULL; |
167 | } | |
18cc8c7e | 168 | |
65575e96 | 169 | if (do_stat(filename, &st) == -1) { |
45c49b52 | 170 | rsyserr(FERROR, errno, "stat(%s)", filename); |
65575e96 AT |
171 | ok = 0; |
172 | } else if ((st.st_mode & 06) != 0) { | |
173 | rprintf(FERROR,"password file must not be other-accessible\n"); | |
174 | ok = 0; | |
38cab94d | 175 | } else if (am_root && st.st_uid != 0) { |
65575e96 AT |
176 | rprintf(FERROR,"password file must be owned by root when running as root\n"); |
177 | ok = 0; | |
178 | } | |
179 | if (!ok) { | |
180 | rprintf(FERROR,"continuing without password file\n"); | |
38cab94d WD |
181 | if (envpw) |
182 | rprintf(FERROR, "using RSYNC_PASSWORD environment variable.\n"); | |
65575e96 AT |
183 | close(fd); |
184 | return NULL; | |
185 | } | |
186 | ||
38cab94d WD |
187 | if (envpw) |
188 | rprintf(FERROR, "RSYNC_PASSWORD environment variable ignored\n"); | |
65575e96 | 189 | |
38cab94d WD |
190 | n = read(fd, buffer, sizeof buffer - 1); |
191 | close(fd); | |
192 | if (n > 0) { | |
193 | buffer[n] = '\0'; | |
194 | if ((p = strtok(buffer, "\n\r")) != NULL) | |
195 | return strdup(p); | |
18cc8c7e | 196 | } |
65575e96 AT |
197 | |
198 | return NULL; | |
199 | } | |
200 | ||
bf011fed WD |
201 | /* Generate an MD4 hash created from the combination of the password |
202 | * and the challenge string and return it base64-encoded. */ | |
6e4fb64e | 203 | static void generate_hash(char *in, char *challenge, char *out) |
bcb7e502 | 204 | { |
5037cf3a | 205 | char buf[MD4_SUM_LENGTH]; |
bcb7e502 | 206 | |
ba582f75 | 207 | sum_init(0); |
bcb7e502 AT |
208 | sum_update(in, strlen(in)); |
209 | sum_update(challenge, strlen(challenge)); | |
210 | sum_end(buf); | |
211 | ||
5037cf3a | 212 | base64_encode(buf, MD4_SUM_LENGTH, out); |
bcb7e502 AT |
213 | } |
214 | ||
18cc8c7e WD |
215 | /* Possibly negotiate authentication with the client. Use "leader" to |
216 | * start off the auth if necessary. | |
217 | * | |
218 | * Return NULL if authentication failed. Return "" if anonymous access. | |
219 | * Otherwise return username. | |
220 | */ | |
5037cf3a WD |
221 | char *auth_server(int f_in, int f_out, int module, char *host, char *addr, |
222 | char *leader) | |
bcb7e502 AT |
223 | { |
224 | char *users = lp_auth_users(module); | |
bf011fed | 225 | char challenge[MD4_SUM_LENGTH*2]; |
d999d312 | 226 | char line[BIGPATHBUFLEN]; |
5037cf3a WD |
227 | char secret[512]; |
228 | char pass2[MD4_SUM_LENGTH*2]; | |
229 | char *tok, *pass; | |
bcb7e502 AT |
230 | |
231 | /* if no auth list then allow anyone in! */ | |
58c9b4b7 WD |
232 | if (!users || !*users) |
233 | return ""; | |
bcb7e502 AT |
234 | |
235 | gen_challenge(addr, challenge); | |
18cc8c7e | 236 | |
bf011fed | 237 | io_printf(f_out, "%s%s\n", leader, challenge); |
bcb7e502 | 238 | |
5037cf3a WD |
239 | if (!read_line(f_in, line, sizeof line - 1) |
240 | || (pass = strchr(line, ' ')) == NULL) { | |
241 | rprintf(FLOG, "auth failed on module %s from %s (%s): " | |
242 | "invalid challenge response\n", | |
243 | lp_name(module), host, addr); | |
d0d56395 | 244 | return NULL; |
5037cf3a WD |
245 | } |
246 | *pass++ = '\0'; | |
18cc8c7e | 247 | |
5037cf3a WD |
248 | if (!(users = strdup(users))) |
249 | out_of_memory("auth_server"); | |
c8e78d87 | 250 | |
5037cf3a WD |
251 | for (tok = strtok(users, " ,\t"); tok; tok = strtok(NULL, " ,\t")) { |
252 | if (wildmatch(tok, line)) | |
58c9b4b7 | 253 | break; |
c8e78d87 AT |
254 | } |
255 | free(users); | |
256 | ||
5037cf3a WD |
257 | if (!tok) { |
258 | rprintf(FLOG, "auth failed on module %s from %s (%s): " | |
259 | "unauthorized user\n", | |
260 | lp_name(module), host, addr); | |
d0d56395 | 261 | return NULL; |
5037cf3a | 262 | } |
18cc8c7e | 263 | |
58c9b4b7 | 264 | memset(secret, 0, sizeof secret); |
5037cf3a | 265 | if (!get_secret(module, line, secret, sizeof secret - 1)) { |
58c9b4b7 | 266 | memset(secret, 0, sizeof secret); |
5037cf3a WD |
267 | rprintf(FLOG, "auth failed on module %s from %s (%s): " |
268 | "missing secret for user \"%s\"\n", | |
269 | lp_name(module), host, addr, line); | |
d0d56395 | 270 | return NULL; |
bcb7e502 AT |
271 | } |
272 | ||
bf011fed | 273 | generate_hash(secret, challenge, pass2); |
58c9b4b7 | 274 | memset(secret, 0, sizeof secret); |
18cc8c7e | 275 | |
5037cf3a WD |
276 | if (strcmp(pass, pass2) != 0) { |
277 | rprintf(FLOG, "auth failed on module %s from %s (%s): " | |
278 | "password mismatch\n", | |
279 | lp_name(module), host, addr); | |
280 | return NULL; | |
281 | } | |
d0d56395 | 282 | |
5037cf3a | 283 | return strdup(line); |
bcb7e502 AT |
284 | } |
285 | ||
286 | ||
287 | void auth_client(int fd, char *user, char *challenge) | |
288 | { | |
289 | char *pass; | |
5037cf3a | 290 | char pass2[MD4_SUM_LENGTH*2]; |
bcb7e502 | 291 | |
ef383c0d | 292 | if (!user || !*user) |
4b2f6a7c | 293 | user = "nobody"; |
bcb7e502 | 294 | |
58c9b4b7 WD |
295 | if (!(pass = getpassf(password_file)) |
296 | && !(pass = getenv("RSYNC_PASSWORD"))) { | |
64bd7568 | 297 | /* XXX: cyeoh says that getpass is deprecated, because |
908f5a9f MP |
298 | * it may return a truncated password on some systems, |
299 | * and it is not in the LSB. | |
300 | * | |
301 | * Andrew Klein says that getpassphrase() is present | |
302 | * on Solaris and reads up to 256 characters. | |
303 | * | |
304 | * OpenBSD has a readpassphrase() that might be more suitable. | |
305 | */ | |
bcb7e502 AT |
306 | pass = getpass("Password: "); |
307 | } | |
308 | ||
38cab94d | 309 | if (!pass) |
bcb7e502 | 310 | pass = ""; |
bcb7e502 AT |
311 | |
312 | generate_hash(pass, challenge, pass2); | |
bcb7e502 AT |
313 | io_printf(fd, "%s %s\n", user, pass2); |
314 | } |