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86cd93d8 ER |
1 | --- openssh-5.9p1/auth2-pubkey.c 2011-05-29 13:39:38.000000000 +0200 |
2 | +++ openssh-5.9p1/auth2-pubkey.c 2011-09-13 01:17:16.352798645 +0200 | |
3 | @@ -27,6 +27,7 @@ | |
4 | ||
5 | #include <sys/types.h> | |
6 | #include <sys/stat.h> | |
7 | +#include <sys/wait.h> | |
8 | ||
9 | #include <fcntl.h> | |
10 | #include <pwd.h> | |
11 | @@ -256,27 +257,15 @@ match_principals_file(char *file, struct | |
12 | ||
13 | /* return 1 if user allows given key */ | |
14 | static int | |
15 | -user_key_allowed2(struct passwd *pw, Key *key, char *file) | |
16 | +user_search_key_in_file(FILE *f, char *file, Key* key, struct passwd *pw) | |
17 | { | |
18 | char line[SSH_MAX_PUBKEY_BYTES]; | |
19 | const char *reason; | |
20 | int found_key = 0; | |
21 | - FILE *f; | |
22 | u_long linenum = 0; | |
23 | Key *found; | |
24 | char *fp; | |
25 | ||
26 | - /* Temporarily use the user's uid. */ | |
27 | - temporarily_use_uid(pw); | |
28 | - | |
29 | - debug("trying public key file %s", file); | |
30 | - f = auth_openkeyfile(file, pw, options.strict_modes); | |
31 | - | |
32 | - if (!f) { | |
33 | - restore_uid(); | |
34 | - return 0; | |
35 | - } | |
36 | - | |
37 | found_key = 0; | |
38 | found = key_new(key_is_cert(key) ? KEY_UNSPEC : key->type); | |
39 | ||
40 | @@ -369,8 +358,6 @@ user_key_allowed2(struct passwd *pw, Key | |
41 | break; | |
42 | } | |
43 | } | |
44 | - restore_uid(); | |
45 | - fclose(f); | |
46 | key_free(found); | |
47 | if (!found_key) | |
48 | debug2("key not found"); | |
49 | @@ -432,13 +419,191 @@ user_cert_trusted_ca(struct passwd *pw, | |
50 | return ret; | |
51 | } | |
52 | ||
53 | -/* check whether given key is in .ssh/authorized_keys* */ | |
54 | +/* return 1 if user allows given key */ | |
55 | +static int | |
56 | +user_key_allowed2(struct passwd *pw, Key *key, char *file) | |
57 | +{ | |
58 | + FILE *f; | |
59 | + int found_key = 0; | |
60 | + | |
61 | + /* Temporarily use the user's uid. */ | |
62 | + temporarily_use_uid(pw); | |
63 | + | |
64 | + debug("trying public key file %s", file); | |
65 | + f = auth_openkeyfile(file, pw, options.strict_modes); | |
66 | + | |
67 | + if (f) { | |
68 | + found_key = user_search_key_in_file (f, file, key, pw); | |
69 | + fclose(f); | |
70 | + } | |
71 | + | |
72 | + restore_uid(); | |
73 | + return found_key; | |
74 | +} | |
75 | + | |
76 | +#ifdef WITH_AUTHORIZED_KEYS_COMMAND | |
77 | + | |
78 | +#define WHITESPACE " \t\r\n" | |
79 | + | |
80 | +/* return 1 if user allows given key */ | |
81 | +static int | |
82 | +user_key_via_command_allowed2(struct passwd *pw, Key *key) | |
83 | +{ | |
84 | + FILE *f; | |
85 | + int found_key = 0; | |
86 | + char *progname = NULL; | |
87 | + char *cp; | |
88 | + struct passwd *runas_pw; | |
89 | + struct stat st; | |
90 | + int childdescriptors[2], i; | |
91 | + pid_t pstat, pid, child; | |
92 | + | |
93 | + if (options.authorized_keys_command == NULL || options.authorized_keys_command[0] != '/') | |
94 | + return 0; | |
95 | + | |
96 | + /* get the run as identity from config */ | |
97 | + runas_pw = (options.authorized_keys_command_runas == NULL)? pw | |
98 | + : getpwnam (options.authorized_keys_command_runas); | |
99 | + if (!runas_pw) { | |
100 | + error("%s: getpwnam(\"%s\"): %s", __func__, | |
101 | + options.authorized_keys_command_runas, strerror(errno)); | |
102 | + return 0; | |
103 | + } | |
104 | + | |
105 | + /* Temporarily use the specified uid. */ | |
106 | + if (runas_pw->pw_uid != 0) | |
107 | + temporarily_use_uid(runas_pw); | |
108 | + | |
109 | + progname = xstrdup(options.authorized_keys_command); | |
110 | + | |
111 | + debug3("%s: checking program '%s'", __func__, progname); | |
112 | + | |
113 | + if (stat (progname, &st) < 0) { | |
114 | + error("%s: stat(\"%s\"): %s", __func__, | |
115 | + progname, strerror(errno)); | |
116 | + goto go_away; | |
117 | + } | |
118 | + | |
119 | + if (st.st_uid != 0 || (st.st_mode & 022) != 0) { | |
120 | + error("bad ownership or modes for AuthorizedKeysCommand \"%s\"", | |
121 | + progname); | |
122 | + goto go_away; | |
123 | + } | |
124 | + | |
125 | + if (!S_ISREG(st.st_mode)) { | |
126 | + error("AuthorizedKeysCommand \"%s\" is not a regular file", | |
127 | + progname); | |
128 | + goto go_away; | |
129 | + } | |
130 | + | |
131 | + /* | |
132 | + * Descend the path, checking that each component is a | |
133 | + * root-owned directory with strict permissions. | |
134 | + */ | |
135 | + do { | |
136 | + if ((cp = strrchr(progname, '/')) == NULL) | |
137 | + break; | |
138 | + else | |
139 | + *cp = '\0'; | |
140 | + | |
141 | + debug3("%s: checking component '%s'", __func__, (*progname == '\0' ? "/" : progname)); | |
142 | + | |
143 | + if (stat((*progname == '\0' ? "/" : progname), &st) != 0) { | |
144 | + error("%s: stat(\"%s\"): %s", __func__, | |
145 | + progname, strerror(errno)); | |
146 | + goto go_away; | |
147 | + } | |
148 | + if (st.st_uid != 0 || (st.st_mode & 022) != 0) { | |
149 | + error("bad ownership or modes for AuthorizedKeysCommand path component \"%s\"", | |
150 | + progname); | |
151 | + goto go_away; | |
152 | + } | |
153 | + if (!S_ISDIR(st.st_mode)) { | |
154 | + error("AuthorizedKeysCommand path component \"%s\" is not a directory", | |
155 | + progname); | |
156 | + goto go_away; | |
157 | + } | |
158 | + } while (1); | |
159 | + | |
160 | + /* open the pipe and read the keys */ | |
161 | + if (pipe(childdescriptors)) { | |
162 | + error("failed to pipe(2) for AuthorizedKeysCommand: %s", | |
163 | + strerror(errno)); | |
164 | + goto go_away; | |
165 | + } | |
166 | + | |
167 | + child = fork(); | |
168 | + if (child == -1) { | |
169 | + error("failed to fork(2) for AuthorizedKeysCommand: %s", | |
170 | + strerror(errno)); | |
171 | + goto go_away; | |
172 | + } else if (child == 0) { | |
173 | + /* we're in the child process here -- we should never return from this block. */ | |
174 | + /* permanently drop privs in child process */ | |
175 | + if (runas_pw->pw_uid != 0) { | |
176 | + restore_uid(); | |
177 | + permanently_set_uid(runas_pw); | |
178 | + } | |
179 | + | |
180 | + close(childdescriptors[0]); | |
181 | + /* put the write end of the pipe on stdout (FD 1) */ | |
182 | + if (dup2(childdescriptors[1], 1) == -1) { | |
183 | + error("failed to dup2(2) from AuthorizedKeysCommand: %s", | |
184 | + strerror(errno)); | |
185 | + _exit(127); | |
186 | + } | |
187 | + | |
188 | + debug3("about to execl() AuthorizedKeysCommand: \"%s\" \"%s\"", options.authorized_keys_command, pw->pw_name); | |
189 | + /* see session.c:child_close_fds() */ | |
190 | + for (i = 3; i < 64; ++i) { | |
191 | + close(i); | |
192 | + } | |
193 | + | |
194 | + execl(options.authorized_keys_command, options.authorized_keys_command, pw->pw_name, NULL); | |
195 | + | |
196 | + /* if we got here, it didn't work */ | |
197 | + error("failed to execl AuthorizedKeysCommand: %s", strerror(errno)); /* this won't work because we closed the fds above */ | |
198 | + _exit(127); | |
199 | + } | |
200 | + | |
201 | + close(childdescriptors[1]); | |
202 | + f = fdopen(childdescriptors[0], "r"); | |
203 | + if (!f) { | |
204 | + error("%s: could not buffer FDs from AuthorizedKeysCommand (\"%s\", \"r\"): %s", __func__, | |
205 | + options.authorized_keys_command, strerror (errno)); | |
206 | + goto go_away; | |
207 | + } | |
208 | + | |
209 | + found_key = user_search_key_in_file (f, options.authorized_keys_command, key, pw); | |
210 | + fclose (f); | |
211 | + do { | |
212 | + pid = waitpid(child, &pstat, 0); | |
213 | + } while (pid == -1 && errno == EINTR); | |
214 | + | |
215 | + /* what about the return value from the child process? */ | |
216 | +go_away: | |
217 | + if (progname) | |
218 | + xfree (progname); | |
219 | + | |
220 | + if (runas_pw->pw_uid != 0) | |
221 | + restore_uid(); | |
222 | + return found_key; | |
223 | +} | |
224 | +#endif | |
225 | + | |
226 | +/* check whether given key is in <AuthorizedKeysCommand or .ssh/authorized_keys* */ | |
227 | int | |
228 | user_key_allowed(struct passwd *pw, Key *key) | |
229 | { | |
230 | u_int success, i; | |
231 | char *file; | |
232 | ||
233 | +#ifdef WITH_AUTHORIZED_KEYS_COMMAND | |
234 | + success = user_key_via_command_allowed2(pw, key); | |
235 | + if (success > 0) | |
236 | + return success; | |
237 | +#endif | |
238 | + | |
239 | if (auth_key_is_revoked(key)) | |
240 | return 0; | |
241 | if (key_is_cert(key) && auth_key_is_revoked(key->cert->signature_key)) | |
242 | --- openssh-5.9p1/configure.ac 2011-08-18 06:48:24.000000000 +0200 | |
243 | +++ openssh-5.9p1/configure.ac 2011-09-13 01:17:16.388769789 +0200 | |
244 | @@ -1421,6 +1421,18 @@ AC_ARG_WITH([audit], | |
245 | esac ] | |
246 | ) | |
247 | ||
248 | +# Check whether user wants AuthorizedKeysCommand support | |
249 | +AKC_MSG="no" | |
250 | +AC_ARG_WITH(authorized-keys-command, | |
251 | + [ --with-authorized-keys-command Enable AuthorizedKeysCommand support], | |
252 | + [ | |
253 | + if test "x$withval" != "xno" ; then | |
254 | + AC_DEFINE([WITH_AUTHORIZED_KEYS_COMMAND], 1, [Enable AuthorizedKeysCommand support]) | |
255 | + AKC_MSG="yes" | |
256 | + fi | |
257 | + ] | |
258 | +) | |
259 | + | |
260 | dnl Checks for library functions. Please keep in alphabetical order | |
261 | AC_CHECK_FUNCS([ \ | |
262 | arc4random \ | |
263 | @@ -4235,6 +4247,7 @@ echo " SELinux support | |
264 | echo " Smartcard support: $SCARD_MSG" | |
265 | echo " S/KEY support: $SKEY_MSG" | |
266 | echo " TCP Wrappers support: $TCPW_MSG" | |
267 | +echo " AuthorizedKeysCommand support: $AKC_MSG" | |
268 | echo " MD5 password support: $MD5_MSG" | |
269 | echo " libedit support: $LIBEDIT_MSG" | |
270 | echo " Solaris process contract support: $SPC_MSG" | |
271 | --- openssh-5.9p1/servconf.c 2011-06-23 00:30:03.000000000 +0200 | |
272 | +++ openssh-5.9p1/servconf.c 2011-09-13 01:18:27.828816240 +0200 | |
273 | @@ -132,6 +132,8 @@ initialize_server_options(ServerOptions | |
274 | options->num_permitted_opens = -1; | |
275 | options->adm_forced_command = NULL; | |
276 | options->chroot_directory = NULL; | |
277 | + options->authorized_keys_command = NULL; | |
278 | + options->authorized_keys_command_runas = NULL; | |
279 | options->zero_knowledge_password_authentication = -1; | |
280 | options->revoked_keys_file = NULL; | |
281 | options->trusted_user_ca_keys = NULL; | |
282 | @@ -324,6 +326,7 @@ typedef enum { | |
283 | sZeroKnowledgePasswordAuthentication, sHostCertificate, | |
284 | sRevokedKeys, sTrustedUserCAKeys, sAuthorizedPrincipalsFile, | |
285 | sKexAlgorithms, sIPQoS, | |
286 | + sAuthorizedKeysCommand, sAuthorizedKeysCommandRunAs, | |
287 | sDeprecated, sUnsupported | |
288 | } ServerOpCodes; | |
289 | ||
290 | @@ -448,6 +451,13 @@ static struct { | |
291 | { "authorizedprincipalsfile", sAuthorizedPrincipalsFile, SSHCFG_ALL }, | |
292 | { "kexalgorithms", sKexAlgorithms, SSHCFG_GLOBAL }, | |
293 | { "ipqos", sIPQoS, SSHCFG_ALL }, | |
294 | +#ifdef WITH_AUTHORIZED_KEYS_COMMAND | |
295 | + { "authorizedkeyscommand", sAuthorizedKeysCommand, SSHCFG_ALL }, | |
296 | + { "authorizedkeyscommandrunas", sAuthorizedKeysCommandRunAs, SSHCFG_ALL }, | |
297 | +#else | |
298 | + { "authorizedkeyscommand", sUnsupported, SSHCFG_ALL }, | |
299 | + { "authorizedkeyscommandrunas", sUnsupported, SSHCFG_ALL }, | |
300 | +#endif | |
301 | { NULL, sBadOption, 0 } | |
302 | }; | |
303 | ||
304 | @@ -1395,6 +1405,20 @@ process_server_config_line(ServerOptions | |
305 | } | |
306 | break; | |
307 | ||
308 | + case sAuthorizedKeysCommand: | |
309 | + len = strspn(cp, WHITESPACE); | |
310 | + if (*activep && options->authorized_keys_command == NULL) | |
311 | + options->authorized_keys_command = xstrdup(cp + len); | |
312 | + return 0; | |
313 | + | |
314 | + case sAuthorizedKeysCommandRunAs: | |
315 | + charptr = &options->authorized_keys_command_runas; | |
316 | + | |
317 | + arg = strdelim(&cp); | |
318 | + if (*activep && *charptr == NULL) | |
319 | + *charptr = xstrdup(arg); | |
320 | + break; | |
321 | + | |
322 | case sDeprecated: | |
323 | logit("%s line %d: Deprecated option %s", | |
324 | filename, linenum, arg); | |
325 | @@ -1499,6 +1523,8 @@ copy_set_server_options(ServerOptions *d | |
326 | M_CP_INTOPT(hostbased_uses_name_from_packet_only); | |
327 | M_CP_INTOPT(kbd_interactive_authentication); | |
328 | M_CP_INTOPT(zero_knowledge_password_authentication); | |
329 | + M_CP_STROPT(authorized_keys_command); | |
330 | + M_CP_STROPT(authorized_keys_command_runas); | |
331 | M_CP_INTOPT(permit_root_login); | |
332 | M_CP_INTOPT(permit_empty_passwd); | |
333 | ||
334 | @@ -1758,6 +1784,8 @@ dump_config(ServerOptions *o) | |
335 | dump_cfg_string(sRevokedKeys, o->revoked_keys_file); | |
336 | dump_cfg_string(sAuthorizedPrincipalsFile, | |
337 | o->authorized_principals_file); | |
338 | + dump_cfg_string(sAuthorizedKeysCommand, o->authorized_keys_command); | |
339 | + dump_cfg_string(sAuthorizedKeysCommandRunAs, o->authorized_keys_command_runas); | |
340 | ||
341 | /* string arguments requiring a lookup */ | |
342 | dump_cfg_string(sLogLevel, log_level_name(o->log_level)); | |
343 | --- openssh-5.9p1/servconf.h 2011-06-23 00:30:03.000000000 +0200 | |
344 | +++ openssh-5.9p1/servconf.h 2011-09-13 01:17:16.481674272 +0200 | |
345 | @@ -166,6 +166,8 @@ typedef struct { | |
346 | char *revoked_keys_file; | |
347 | char *trusted_user_ca_keys; | |
348 | char *authorized_principals_file; | |
349 | + char *authorized_keys_command; | |
350 | + char *authorized_keys_command_runas; | |
351 | } ServerOptions; | |
352 | ||
353 | /* | |
354 | --- openssh-5.9p1/sshd_config.0 2011-09-07 01:16:30.000000000 +0200 | |
355 | +++ openssh-5.9p1/sshd_config.0 2011-09-13 01:17:16.509816302 +0200 | |
356 | @@ -71,6 +71,23 @@ DESCRIPTION | |
357 | ||
358 | See PATTERNS in ssh_config(5) for more information on patterns. | |
359 | ||
360 | + AuthorizedKeysCommand | |
361 | + | |
362 | + Specifies a program to be used for lookup of the user's | |
363 | + public keys. The program will be invoked with its first | |
364 | + argument the name of the user being authorized, and should produce | |
365 | + on standard output AuthorizedKeys lines (see AUTHORIZED_KEYS | |
366 | + in sshd(8)). By default (or when set to the empty string) there is no | |
367 | + AuthorizedKeysCommand run. If the AuthorizedKeysCommand does not successfully | |
368 | + authorize the user, authorization falls through to the | |
369 | + AuthorizedKeysFile. Note that this option has an effect | |
370 | + only with PubkeyAuthentication turned on. | |
371 | + | |
372 | + AuthorizedKeysCommandRunAs | |
373 | + Specifies the user under whose account the AuthorizedKeysCommand is run. | |
374 | + Empty string (the default value) means the user being authorized | |
375 | + is used. | |
376 | + | |
377 | AuthorizedKeysFile | |
378 | Specifies the file that contains the public keys that can be used | |
379 | for user authentication. The format is described in the | |
380 | @@ -401,7 +418,8 @@ DESCRIPTION | |
381 | ||
382 | Only a subset of keywords may be used on the lines following a | |
383 | Match keyword. Available keywords are AllowAgentForwarding, | |
384 | - AllowTcpForwarding, AuthorizedKeysFile, AuthorizedPrincipalsFile, | |
385 | + AllowTcpForwarding, AuthorizedKeysFile, AuthorizedKeysCommand, | |
386 | + AuthorizedKeysCommandRunAs, AuthorizedPrincipalsFile, | |
387 | Banner, ChrootDirectory, ForceCommand, GatewayPorts, | |
388 | GSSAPIAuthentication, HostbasedAuthentication, | |
389 | HostbasedUsesNameFromPacketOnly, KbdInteractiveAuthentication, | |
390 | --- openssh-5.9p1/sshd_config.5 2011-08-05 22:17:33.000000000 +0200 | |
391 | +++ openssh-5.9p1/sshd_config.5 2011-09-13 01:17:16.536674498 +0200 | |
392 | @@ -706,6 +706,8 @@ Available keywords are | |
393 | .Cm AllowAgentForwarding , | |
394 | .Cm AllowTcpForwarding , | |
395 | .Cm AuthorizedKeysFile , | |
396 | +.Cm AuthorizedKeysCommand , | |
397 | +.Cm AuthorizedKeysCommandRunAs , | |
398 | .Cm AuthorizedPrincipalsFile , | |
399 | .Cm Banner , | |
400 | .Cm ChrootDirectory , | |
401 | @@ -718,6 +720,7 @@ Available keywords are | |
402 | .Cm KerberosAuthentication , | |
403 | .Cm MaxAuthTries , | |
404 | .Cm MaxSessions , | |
405 | +.Cm PubkeyAuthentication , | |
406 | .Cm PasswordAuthentication , | |
407 | .Cm PermitEmptyPasswords , | |
408 | .Cm PermitOpen , | |
409 | @@ -920,6 +923,20 @@ Specifies a list of revoked public keys. | |
410 | Keys listed in this file will be refused for public key authentication. | |
411 | Note that if this file is not readable, then public key authentication will | |
412 | be refused for all users. | |
413 | +.It Cm AuthorizedKeysCommand | |
414 | +Specifies a program to be used for lookup of the user's | |
415 | +public keys. The program will be invoked with its first | |
416 | +argument the name of the user being authorized, and should produce | |
417 | +on standard output AuthorizedKeys lines (see AUTHORIZED_KEYS | |
418 | +in sshd(8)). By default (or when set to the empty string) there is no | |
419 | +AuthorizedKeysCommand run. If the AuthorizedKeysCommand does not successfully | |
420 | +authorize the user, authorization falls through to the | |
421 | +AuthorizedKeysFile. Note that this option has an effect | |
422 | +only with PubkeyAuthentication turned on. | |
423 | +.It Cm AuthorizedKeysCommandRunAs | |
424 | +Specifies the user under whose account the AuthorizedKeysCommand is run. Empty | |
425 | +string (the default value) means the user being authorized is used. | |
426 | +.Dq | |
427 | .It Cm RhostsRSAAuthentication | |
428 | Specifies whether rhosts or /etc/hosts.equiv authentication together | |
429 | with successful RSA host authentication is allowed. | |
430 | --- openssh-5.9p1/sshd_config 2011-05-29 13:39:39.000000000 +0200 | |
431 | +++ openssh-5.9p1/sshd_config 2011-09-13 01:17:16.555799142 +0200 | |
432 | @@ -49,6 +49,9 @@ | |
433 | # but this is overridden so installations will only check .ssh/authorized_keys | |
434 | AuthorizedKeysFile .ssh/authorized_keys | |
435 | ||
436 | +#AuthorizedKeysCommand none | |
437 | +#AuthorizedKeysCommandRunAs nobody | |
438 | + | |
439 | # For this to work you will also need host keys in /etc/ssh/ssh_known_hosts | |
440 | #RhostsRSAAuthentication no | |
441 | # similar for protocol version 2 |