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 | ||
54 | /* create a 16 byte challenge buffer */ | |
55 | static void gen_challenge(char *addr, char *challenge) | |
56 | { | |
57 | char input[32]; | |
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 | ||
68 | sum_init(); | |
58c9b4b7 | 69 | sum_update(input, sizeof input); |
bcb7e502 AT |
70 | sum_end(challenge); |
71 | } | |
72 | ||
73 | ||
38cab94d WD |
74 | /* Return the secret for a user from the secret file, null terminated. |
75 | * Maximum length is len (not counting the null). */ | |
bcb7e502 AT |
76 | static int get_secret(int module, char *user, char *secret, int len) |
77 | { | |
78 | char *fname = lp_secrets_file(module); | |
d1be2312 | 79 | STRUCT_STAT st; |
38cab94d WD |
80 | int fd, ok = 1; |
81 | char ch, *p; | |
bcb7e502 | 82 | |
38cab94d WD |
83 | if (!fname || !*fname) |
84 | return 0; | |
bcb7e502 | 85 | |
38cab94d WD |
86 | if ((fd = open(fname, O_RDONLY)) < 0) |
87 | return 0; | |
bcb7e502 | 88 | |
d1be2312 | 89 | if (do_stat(fname, &st) == -1) { |
a039749b | 90 | rsyserr(FERROR, errno, "stat(%s)", fname); |
d1be2312 | 91 | ok = 0; |
3ca8e68f DD |
92 | } else if (lp_strict_modes(module)) { |
93 | if ((st.st_mode & 06) != 0) { | |
94 | rprintf(FERROR,"secrets file must not be other-accessible (see strict modes option)\n"); | |
95 | ok = 0; | |
96 | } else if (am_root && (st.st_uid != 0)) { | |
97 | rprintf(FERROR,"secrets file must be owned by root when running as root (see strict modes)\n"); | |
98 | ok = 0; | |
99 | } | |
d1be2312 DD |
100 | } |
101 | if (!ok) { | |
102 | rprintf(FERROR,"continuing without secrets file\n"); | |
103 | close(fd); | |
104 | return 0; | |
105 | } | |
106 | ||
38cab94d WD |
107 | if (*user == '#') { |
108 | /* Reject attempt to match a comment. */ | |
109 | close(fd); | |
110 | return 0; | |
111 | } | |
112 | ||
113 | /* Try to find a line that starts with the user name and a ':'. */ | |
114 | p = user; | |
115 | while (1) { | |
116 | if (read(fd, &ch, 1) != 1) { | |
117 | close(fd); | |
118 | return 0; | |
119 | } | |
120 | if (ch == '\n') | |
121 | p = user; | |
122 | else if (p) { | |
123 | if (*p == ch) | |
124 | p++; | |
125 | else if (!*p && ch == ':') | |
126 | break; | |
127 | else | |
128 | p = NULL; | |
bcb7e502 | 129 | } |
bcb7e502 AT |
130 | } |
131 | ||
38cab94d WD |
132 | /* Slurp the secret into the "secret" buffer. */ |
133 | p = secret; | |
134 | while (len > 0) { | |
135 | if (read(fd, p, 1) != 1 || *p == '\n') | |
136 | break; | |
137 | if (*p == '\r') | |
138 | continue; | |
139 | p++; | |
140 | len--; | |
141 | } | |
142 | *p = '\0'; | |
bcb7e502 | 143 | close(fd); |
bcb7e502 | 144 | |
bcb7e502 AT |
145 | return 1; |
146 | } | |
147 | ||
65575e96 AT |
148 | static char *getpassf(char *filename) |
149 | { | |
65575e96 | 150 | STRUCT_STAT st; |
38cab94d WD |
151 | char buffer[512], *p; |
152 | int fd, n, ok = 1; | |
153 | char *envpw = getenv("RSYNC_PASSWORD"); | |
65575e96 | 154 | |
38cab94d WD |
155 | if (!filename) |
156 | return NULL; | |
65575e96 | 157 | |
38cab94d | 158 | if ((fd = open(filename,O_RDONLY)) < 0) { |
4a13b9d5 | 159 | rsyserr(FERROR, errno, "could not open password file \"%s\"",filename); |
38cab94d | 160 | if (envpw) |
18cc8c7e | 161 | rprintf(FERROR, "falling back to RSYNC_PASSWORD environment variable.\n"); |
65575e96 AT |
162 | return NULL; |
163 | } | |
18cc8c7e | 164 | |
65575e96 | 165 | if (do_stat(filename, &st) == -1) { |
a039749b | 166 | rsyserr(FERROR, errno, "stat(%s)", filename); |
65575e96 AT |
167 | ok = 0; |
168 | } else if ((st.st_mode & 06) != 0) { | |
169 | rprintf(FERROR,"password file must not be other-accessible\n"); | |
170 | ok = 0; | |
38cab94d | 171 | } else if (am_root && st.st_uid != 0) { |
65575e96 AT |
172 | rprintf(FERROR,"password file must be owned by root when running as root\n"); |
173 | ok = 0; | |
174 | } | |
175 | if (!ok) { | |
176 | rprintf(FERROR,"continuing without password file\n"); | |
38cab94d WD |
177 | if (envpw) |
178 | rprintf(FERROR, "using RSYNC_PASSWORD environment variable.\n"); | |
65575e96 AT |
179 | close(fd); |
180 | return NULL; | |
181 | } | |
182 | ||
38cab94d WD |
183 | if (envpw) |
184 | rprintf(FERROR, "RSYNC_PASSWORD environment variable ignored\n"); | |
65575e96 | 185 | |
38cab94d WD |
186 | n = read(fd, buffer, sizeof buffer - 1); |
187 | close(fd); | |
188 | if (n > 0) { | |
189 | buffer[n] = '\0'; | |
190 | if ((p = strtok(buffer, "\n\r")) != NULL) | |
191 | return strdup(p); | |
18cc8c7e | 192 | } |
65575e96 AT |
193 | |
194 | return NULL; | |
195 | } | |
196 | ||
bcb7e502 | 197 | /* generate a 16 byte hash from a password and challenge */ |
6e4fb64e | 198 | static void generate_hash(char *in, char *challenge, char *out) |
bcb7e502 AT |
199 | { |
200 | char buf[16]; | |
201 | ||
202 | sum_init(); | |
203 | sum_update(in, strlen(in)); | |
204 | sum_update(challenge, strlen(challenge)); | |
205 | sum_end(buf); | |
206 | ||
207 | base64_encode(buf, 16, out); | |
208 | } | |
209 | ||
18cc8c7e WD |
210 | /* Possibly negotiate authentication with the client. Use "leader" to |
211 | * start off the auth if necessary. | |
212 | * | |
213 | * Return NULL if authentication failed. Return "" if anonymous access. | |
214 | * Otherwise return username. | |
215 | */ | |
973007da | 216 | char *auth_server(int f_in, int f_out, int module, char *addr, char *leader) |
bcb7e502 AT |
217 | { |
218 | char *users = lp_auth_users(module); | |
219 | char challenge[16]; | |
220 | char b64_challenge[30]; | |
e42c9458 | 221 | char line[MAXPATHLEN]; |
d0d56395 | 222 | static char user[100]; |
bcb7e502 AT |
223 | char secret[100]; |
224 | char pass[30]; | |
225 | char pass2[30]; | |
c8e78d87 | 226 | char *tok; |
bcb7e502 AT |
227 | |
228 | /* if no auth list then allow anyone in! */ | |
58c9b4b7 WD |
229 | if (!users || !*users) |
230 | return ""; | |
bcb7e502 AT |
231 | |
232 | gen_challenge(addr, challenge); | |
18cc8c7e | 233 | |
bcb7e502 AT |
234 | base64_encode(challenge, 16, b64_challenge); |
235 | ||
973007da | 236 | io_printf(f_out, "%s%s\n", leader, b64_challenge); |
bcb7e502 | 237 | |
58c9b4b7 | 238 | if (!read_line(f_in, line, sizeof line - 1)) |
d0d56395 | 239 | return NULL; |
bcb7e502 | 240 | |
58c9b4b7 WD |
241 | memset(user, 0, sizeof user); |
242 | memset(pass, 0, sizeof pass); | |
bcb7e502 | 243 | |
58c9b4b7 | 244 | if (sscanf(line,"%99s %29s", user, pass) != 2) |
d0d56395 | 245 | return NULL; |
18cc8c7e | 246 | |
c8e78d87 | 247 | users = strdup(users); |
58c9b4b7 WD |
248 | if (!users) |
249 | return NULL; | |
c8e78d87 AT |
250 | |
251 | for (tok=strtok(users," ,\t"); tok; tok = strtok(NULL," ,\t")) { | |
58c9b4b7 WD |
252 | if (wildmatch(tok, user)) |
253 | break; | |
c8e78d87 AT |
254 | } |
255 | free(users); | |
256 | ||
58c9b4b7 | 257 | if (!tok) |
d0d56395 | 258 | return NULL; |
18cc8c7e | 259 | |
58c9b4b7 WD |
260 | memset(secret, 0, sizeof secret); |
261 | if (!get_secret(module, user, secret, sizeof secret - 1)) { | |
262 | memset(secret, 0, sizeof secret); | |
d0d56395 | 263 | return NULL; |
bcb7e502 AT |
264 | } |
265 | ||
266 | generate_hash(secret, b64_challenge, pass2); | |
58c9b4b7 | 267 | memset(secret, 0, sizeof secret); |
18cc8c7e | 268 | |
d0d56395 AT |
269 | if (strcmp(pass, pass2) == 0) |
270 | return user; | |
271 | ||
272 | return NULL; | |
bcb7e502 AT |
273 | } |
274 | ||
275 | ||
276 | void auth_client(int fd, char *user, char *challenge) | |
277 | { | |
278 | char *pass; | |
279 | char pass2[30]; | |
280 | ||
ef383c0d | 281 | if (!user || !*user) |
4b2f6a7c | 282 | user = "nobody"; |
bcb7e502 | 283 | |
58c9b4b7 WD |
284 | if (!(pass = getpassf(password_file)) |
285 | && !(pass = getenv("RSYNC_PASSWORD"))) { | |
64bd7568 | 286 | /* XXX: cyeoh says that getpass is deprecated, because |
908f5a9f MP |
287 | * it may return a truncated password on some systems, |
288 | * and it is not in the LSB. | |
289 | * | |
290 | * Andrew Klein says that getpassphrase() is present | |
291 | * on Solaris and reads up to 256 characters. | |
292 | * | |
293 | * OpenBSD has a readpassphrase() that might be more suitable. | |
294 | */ | |
bcb7e502 AT |
295 | pass = getpass("Password: "); |
296 | } | |
297 | ||
38cab94d | 298 | if (!pass) |
bcb7e502 | 299 | pass = ""; |
bcb7e502 AT |
300 | |
301 | generate_hash(pass, challenge, pass2); | |
bcb7e502 AT |
302 | io_printf(fd, "%s %s\n", user, pass2); |
303 | } | |
304 | ||
65575e96 | 305 |