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1 | diff -up openssh-5.8p1/auth2-pubkey.c.akc openssh-5.8p1/auth2-pubkey.c | |
2 | --- openssh-5.8p1/auth2-pubkey.c.akc 2011-02-10 13:21:27.000000000 +0100 | |
3 | +++ openssh-5.8p1/auth2-pubkey.c 2011-02-10 13:21:28.000000000 +0100 | |
4 | @@ -27,6 +27,7 @@ | |
5 | ||
6 | #include <sys/types.h> | |
7 | #include <sys/stat.h> | |
8 | +#include <sys/wait.h> | |
9 | ||
10 | #include <fcntl.h> | |
11 | #include <pwd.h> | |
12 | @@ -268,27 +269,15 @@ match_principals_file(char *file, struct | |
13 | ||
14 | /* return 1 if user allows given key */ | |
15 | static int | |
16 | -user_key_allowed2(struct passwd *pw, Key *key, char *file) | |
17 | +user_search_key_in_file(FILE *f, char *file, Key* key, struct passwd *pw) | |
18 | { | |
19 | char line[SSH_MAX_PUBKEY_BYTES]; | |
20 | const char *reason; | |
21 | int found_key = 0; | |
22 | - FILE *f; | |
23 | u_long linenum = 0; | |
24 | Key *found; | |
25 | char *fp; | |
26 | ||
27 | - /* Temporarily use the user's uid. */ | |
28 | - temporarily_use_uid(pw); | |
29 | - | |
30 | - debug("trying public key file %s", file); | |
31 | - f = auth_openkeyfile(file, pw, options.strict_modes); | |
32 | - | |
33 | - if (!f) { | |
34 | - restore_uid(); | |
35 | - return 0; | |
36 | - } | |
37 | - | |
38 | found_key = 0; | |
39 | found = key_new(key_is_cert(key) ? KEY_UNSPEC : key->type); | |
40 | ||
41 | @@ -381,8 +370,6 @@ user_key_allowed2(struct passwd *pw, Key | |
42 | break; | |
43 | } | |
44 | } | |
45 | - restore_uid(); | |
46 | - fclose(f); | |
47 | key_free(found); | |
48 | if (!found_key) | |
49 | debug2("key not found"); | |
50 | @@ -444,13 +431,191 @@ user_cert_trusted_ca(struct passwd *pw, | |
51 | return ret; | |
52 | } | |
53 | ||
54 | -/* check whether given key is in .ssh/authorized_keys* */ | |
55 | +/* return 1 if user allows given key */ | |
56 | +static int | |
57 | +user_key_allowed2(struct passwd *pw, Key *key, char *file) | |
58 | +{ | |
59 | + FILE *f; | |
60 | + int found_key = 0; | |
61 | + | |
62 | + /* Temporarily use the user's uid. */ | |
63 | + temporarily_use_uid(pw); | |
64 | + | |
65 | + debug("trying public key file %s", file); | |
66 | + f = auth_openkeyfile(file, pw, options.strict_modes); | |
67 | + | |
68 | + if (f) { | |
69 | + found_key = user_search_key_in_file (f, file, key, pw); | |
70 | + fclose(f); | |
71 | + } | |
72 | + | |
73 | + restore_uid(); | |
74 | + return found_key; | |
75 | +} | |
76 | + | |
77 | +#ifdef WITH_AUTHORIZED_KEYS_COMMAND | |
78 | + | |
79 | +#define WHITESPACE " \t\r\n" | |
80 | + | |
81 | +/* return 1 if user allows given key */ | |
82 | +static int | |
83 | +user_key_via_command_allowed2(struct passwd *pw, Key *key) | |
84 | +{ | |
85 | + FILE *f; | |
86 | + int found_key = 0; | |
87 | + char *progname = NULL; | |
88 | + char *cp; | |
89 | + struct passwd *runas_pw; | |
90 | + struct stat st; | |
91 | + int childdescriptors[2], i; | |
92 | + pid_t pstat, pid, child; | |
93 | + | |
94 | + if (options.authorized_keys_command == NULL || options.authorized_keys_command[0] != '/') | |
95 | + return -1; | |
96 | + | |
97 | + /* get the run as identity from config */ | |
98 | + runas_pw = (options.authorized_keys_command_runas == NULL)? pw | |
99 | + : getpwnam (options.authorized_keys_command_runas); | |
100 | + if (!runas_pw) { | |
101 | + error("%s: getpwnam(\"%s\"): %s", __func__, | |
102 | + options.authorized_keys_command_runas, strerror(errno)); | |
103 | + return 0; | |
104 | + } | |
105 | + | |
106 | + /* Temporarily use the specified uid. */ | |
107 | + if (runas_pw->pw_uid != 0) | |
108 | + temporarily_use_uid(runas_pw); | |
109 | + | |
110 | + progname = xstrdup(options.authorized_keys_command); | |
111 | + | |
112 | + debug3("%s: checking program '%s'", __func__, progname); | |
113 | + | |
114 | + if (stat (progname, &st) < 0) { | |
115 | + error("%s: stat(\"%s\"): %s", __func__, | |
116 | + progname, strerror(errno)); | |
117 | + goto go_away; | |
118 | + } | |
119 | + | |
120 | + if (st.st_uid != 0 || (st.st_mode & 022) != 0) { | |
121 | + error("bad ownership or modes for AuthorizedKeysCommand \"%s\"", | |
122 | + progname); | |
123 | + goto go_away; | |
124 | + } | |
125 | + | |
126 | + if (!S_ISREG(st.st_mode)) { | |
127 | + error("AuthorizedKeysCommand \"%s\" is not a regular file", | |
128 | + progname); | |
129 | + goto go_away; | |
130 | + } | |
131 | + | |
132 | + /* | |
133 | + * Descend the path, checking that each component is a | |
134 | + * root-owned directory with strict permissions. | |
135 | + */ | |
136 | + do { | |
137 | + if ((cp = strrchr(progname, '/')) == NULL) | |
138 | + break; | |
139 | + else | |
140 | + *cp = '\0'; | |
141 | + | |
142 | + debug3("%s: checking component '%s'", __func__, (*progname == '\0' ? "/" : progname)); | |
143 | + | |
144 | + if (stat((*progname == '\0' ? "/" : progname), &st) != 0) { | |
145 | + error("%s: stat(\"%s\"): %s", __func__, | |
146 | + progname, strerror(errno)); | |
147 | + goto go_away; | |
148 | + } | |
149 | + if (st.st_uid != 0 || (st.st_mode & 022) != 0) { | |
150 | + error("bad ownership or modes for AuthorizedKeysCommand path component \"%s\"", | |
151 | + progname); | |
152 | + goto go_away; | |
153 | + } | |
154 | + if (!S_ISDIR(st.st_mode)) { | |
155 | + error("AuthorizedKeysCommand path component \"%s\" is not a directory", | |
156 | + progname); | |
157 | + goto go_away; | |
158 | + } | |
159 | + } while (1); | |
160 | + | |
161 | + /* open the pipe and read the keys */ | |
162 | + if (pipe(childdescriptors)) { | |
163 | + error("failed to pipe(2) for AuthorizedKeysCommand: %s", | |
164 | + strerror(errno)); | |
165 | + goto go_away; | |
166 | + } | |
167 | + | |
168 | + child = fork(); | |
169 | + if (child == -1) { | |
170 | + error("failed to fork(2) for AuthorizedKeysCommand: %s", | |
171 | + strerror(errno)); | |
172 | + goto go_away; | |
173 | + } else if (child == 0) { | |
174 | + /* we're in the child process here -- we should never return from this block. */ | |
175 | + /* permanently drop privs in child process */ | |
176 | + if (runas_pw->pw_uid != 0) { | |
177 | + restore_uid(); | |
178 | + permanently_set_uid(runas_pw); | |
179 | + } | |
180 | + | |
181 | + close(childdescriptors[0]); | |
182 | + /* put the write end of the pipe on stdout (FD 1) */ | |
183 | + if (dup2(childdescriptors[1], 1) == -1) { | |
184 | + error("failed to dup2(2) from AuthorizedKeysCommand: %s", | |
185 | + strerror(errno)); | |
186 | + _exit(127); | |
187 | + } | |
188 | + | |
189 | + debug3("about to execl() AuthorizedKeysCommand: \"%s\" \"%s\"", options.authorized_keys_command, pw->pw_name); | |
190 | + /* see session.c:child_close_fds() */ | |
191 | + for (i = 3; i < 64; ++i) { | |
192 | + close(i); | |
193 | + } | |
194 | + | |
195 | + execl(options.authorized_keys_command, options.authorized_keys_command, pw->pw_name, NULL); | |
196 | + | |
197 | + /* if we got here, it didn't work */ | |
198 | + error("failed to execl AuthorizedKeysCommand: %s", strerror(errno)); /* this won't work because we closed the fds above */ | |
199 | + _exit(127); | |
200 | + } | |
201 | + | |
202 | + close(childdescriptors[1]); | |
203 | + f = fdopen(childdescriptors[0], "r"); | |
204 | + if (!f) { | |
205 | + error("%s: could not buffer FDs from AuthorizedKeysCommand (\"%s\", \"r\"): %s", __func__, | |
206 | + options.authorized_keys_command, strerror (errno)); | |
207 | + goto go_away; | |
208 | + } | |
209 | + | |
210 | + found_key = user_search_key_in_file (f, options.authorized_keys_command, key, pw); | |
211 | + fclose (f); | |
212 | + do { | |
213 | + pid = waitpid(child, &pstat, 0); | |
214 | + } while (pid == -1 && errno == EINTR); | |
215 | + | |
216 | + /* what about the return value from the child process? */ | |
217 | +go_away: | |
218 | + if (progname) | |
219 | + xfree (progname); | |
220 | + | |
221 | + if (runas_pw->pw_uid != 0) | |
222 | + restore_uid(); | |
223 | + return found_key; | |
224 | +} | |
225 | +#endif | |
226 | + | |
227 | +/* check whether given key is in <AuthorizedKeysCommand or .ssh/authorized_keys* */ | |
228 | int | |
229 | user_key_allowed(struct passwd *pw, Key *key) | |
230 | { | |
231 | int success; | |
232 | char *file; | |
233 | ||
234 | +#ifdef WITH_AUTHORIZED_KEYS_COMMAND | |
235 | + success = user_key_via_command_allowed2(pw, key); | |
236 | + if (success > 0) | |
237 | + return success; | |
238 | +#endif | |
239 | + | |
240 | if (auth_key_is_revoked(key)) | |
241 | return 0; | |
242 | if (key_is_cert(key) && auth_key_is_revoked(key->cert->signature_key)) | |
243 | diff -up openssh-5.8p1/configure.ac.akc openssh-5.8p1/configure.ac | |
244 | --- openssh-5.8p1/configure.ac.akc 2011-02-10 13:21:28.000000000 +0100 | |
245 | +++ openssh-5.8p1/configure.ac 2011-02-10 13:21:28.000000000 +0100 | |
246 | @@ -1422,6 +1422,18 @@ AC_ARG_WITH(audit, | |
247 | esac ] | |
248 | ) | |
249 | ||
250 | +# Check whether user wants AuthorizedKeysCommand support | |
251 | +AKC_MSG="no" | |
252 | +AC_ARG_WITH(authorized-keys-command, | |
253 | + [ --with-authorized-keys-command Enable AuthorizedKeysCommand support], | |
254 | + [ | |
255 | + if test "x$withval" != "xno" ; then | |
256 | + AC_DEFINE([WITH_AUTHORIZED_KEYS_COMMAND], 1, [Enable AuthorizedKeysCommand support]) | |
257 | + AKC_MSG="yes" | |
258 | + fi | |
259 | + ] | |
260 | +) | |
261 | + | |
262 | dnl Checks for library functions. Please keep in alphabetical order | |
263 | AC_CHECK_FUNCS( \ | |
264 | arc4random \ | |
265 | @@ -4325,6 +4337,7 @@ echo " SELinux support | |
266 | echo " Smartcard support: $SCARD_MSG" | |
267 | echo " S/KEY support: $SKEY_MSG" | |
268 | echo " TCP Wrappers support: $TCPW_MSG" | |
269 | +echo " AuthorizedKeysCommand support: $AKC_MSG" | |
270 | echo " MD5 password support: $MD5_MSG" | |
271 | echo " libedit support: $LIBEDIT_MSG" | |
272 | echo " Solaris process contract support: $SPC_MSG" | |
273 | diff -up openssh-5.8p1/servconf.c.akc openssh-5.8p1/servconf.c | |
274 | --- openssh-5.8p1/servconf.c.akc 2011-02-10 13:21:28.000000000 +0100 | |
275 | +++ openssh-5.8p1/servconf.c 2011-02-10 13:28:21.000000000 +0100 | |
276 | @@ -134,6 +134,8 @@ initialize_server_options(ServerOptions | |
277 | options->num_permitted_opens = -1; | |
278 | options->adm_forced_command = NULL; | |
279 | options->chroot_directory = NULL; | |
280 | + options->authorized_keys_command = NULL; | |
281 | + options->authorized_keys_command_runas = NULL; | |
282 | options->zero_knowledge_password_authentication = -1; | |
283 | options->revoked_keys_file = NULL; | |
284 | options->trusted_user_ca_keys = NULL; | |
285 | @@ -331,6 +333,7 @@ typedef enum { | |
286 | sZeroKnowledgePasswordAuthentication, sHostCertificate, | |
287 | sRevokedKeys, sTrustedUserCAKeys, sAuthorizedPrincipalsFile, | |
288 | sKexAlgorithms, sIPQoS, | |
289 | + sAuthorizedKeysCommand, sAuthorizedKeysCommandRunAs, | |
290 | sDeprecated, sUnsupported | |
291 | } ServerOpCodes; | |
292 | ||
293 | @@ -456,6 +459,13 @@ static struct { | |
294 | { "authorizedprincipalsfile", sAuthorizedPrincipalsFile, SSHCFG_ALL }, | |
295 | { "kexalgorithms", sKexAlgorithms, SSHCFG_GLOBAL }, | |
296 | { "ipqos", sIPQoS, SSHCFG_ALL }, | |
297 | +#ifdef WITH_AUTHORIZED_KEYS_COMMAND | |
298 | + { "authorizedkeyscommand", sAuthorizedKeysCommand, SSHCFG_ALL }, | |
299 | + { "authorizedkeyscommandrunas", sAuthorizedKeysCommandRunAs, SSHCFG_ALL }, | |
300 | +#else | |
301 | + { "authorizedkeyscommand", sUnsupported, SSHCFG_ALL }, | |
302 | + { "authorizedkeyscommandrunas", sUnsupported, SSHCFG_ALL }, | |
303 | +#endif | |
304 | { NULL, sBadOption, 0 } | |
305 | }; | |
306 | ||
307 | @@ -1406,6 +1416,20 @@ process_server_config_line(ServerOptions | |
308 | } | |
309 | break; | |
310 | ||
311 | + case sAuthorizedKeysCommand: | |
312 | + len = strspn(cp, WHITESPACE); | |
313 | + if (*activep && options->authorized_keys_command == NULL) | |
314 | + options->authorized_keys_command = xstrdup(cp + len); | |
315 | + return 0; | |
316 | + | |
317 | + case sAuthorizedKeysCommandRunAs: | |
318 | + charptr = &options->authorized_keys_command_runas; | |
319 | + | |
320 | + arg = strdelim(&cp); | |
321 | + if (*activep && *charptr == NULL) | |
322 | + *charptr = xstrdup(arg); | |
323 | + break; | |
324 | + | |
325 | case sDeprecated: | |
326 | logit("%s line %d: Deprecated option %s", | |
327 | filename, linenum, arg); | |
328 | @@ -1499,6 +1523,8 @@ copy_set_server_options(ServerOptions *d | |
329 | M_CP_INTOPT(gss_authentication); | |
330 | M_CP_INTOPT(rsa_authentication); | |
331 | M_CP_INTOPT(pubkey_authentication); | |
332 | + M_CP_STROPT(authorized_keys_command); | |
333 | + M_CP_STROPT(authorized_keys_command_runas); | |
334 | M_CP_INTOPT(kerberos_authentication); | |
335 | M_CP_INTOPT(hostbased_authentication); | |
336 | M_CP_INTOPT(hostbased_uses_name_from_packet_only); | |
337 | @@ -1753,6 +1779,8 @@ dump_config(ServerOptions *o) | |
338 | dump_cfg_string(sRevokedKeys, o->revoked_keys_file); | |
339 | dump_cfg_string(sAuthorizedPrincipalsFile, | |
340 | o->authorized_principals_file); | |
341 | + dump_cfg_string(sAuthorizedKeysCommand, o->authorized_keys_command); | |
342 | + dump_cfg_string(sAuthorizedKeysCommandRunAs, o->authorized_keys_command_runas); | |
343 | ||
344 | /* string arguments requiring a lookup */ | |
345 | dump_cfg_string(sLogLevel, log_level_name(o->log_level)); | |
346 | diff -up openssh-5.8p1/servconf.h.akc openssh-5.8p1/servconf.h | |
347 | --- openssh-5.8p1/servconf.h.akc 2011-02-10 13:21:28.000000000 +0100 | |
348 | +++ openssh-5.8p1/servconf.h 2011-02-10 13:21:28.000000000 +0100 | |
349 | @@ -161,6 +161,8 @@ typedef struct { | |
350 | char *revoked_keys_file; | |
351 | char *trusted_user_ca_keys; | |
352 | char *authorized_principals_file; | |
353 | + char *authorized_keys_command; | |
354 | + char *authorized_keys_command_runas; | |
355 | } ServerOptions; | |
356 | ||
357 | void initialize_server_options(ServerOptions *); | |
358 | diff -up openssh-5.8p1/sshd_config.0.akc openssh-5.8p1/sshd_config.0 | |
359 | --- openssh-5.8p1/sshd_config.0.akc 2011-02-10 13:21:28.000000000 +0100 | |
360 | +++ openssh-5.8p1/sshd_config.0 2011-02-10 13:21:28.000000000 +0100 | |
361 | @@ -71,6 +71,23 @@ DESCRIPTION | |
362 | ||
363 | See PATTERNS in ssh_config(5) for more information on patterns. | |
364 | ||
365 | + AuthorizedKeysCommand | |
366 | + | |
367 | + Specifies a program to be used for lookup of the user's | |
368 | + public keys. The program will be invoked with its first | |
369 | + argument the name of the user being authorized, and should produce | |
370 | + on standard output AuthorizedKeys lines (see AUTHORIZED_KEYS | |
371 | + in sshd(8)). By default (or when set to the empty string) there is no | |
372 | + AuthorizedKeysCommand run. If the AuthorizedKeysCommand does not successfully | |
373 | + authorize the user, authorization falls through to the | |
374 | + AuthorizedKeysFile. Note that this option has an effect | |
375 | + only with PubkeyAuthentication turned on. | |
376 | + | |
377 | + AuthorizedKeysCommandRunAs | |
378 | + Specifies the user under whose account the AuthorizedKeysCommand is run. | |
379 | + Empty string (the default value) means the user being authorized | |
380 | + is used. | |
381 | + | |
382 | AuthorizedKeysFile | |
383 | Specifies the file that contains the public keys that can be used | |
384 | for user authentication. The format is described in the | |
385 | @@ -398,7 +415,8 @@ DESCRIPTION | |
386 | ||
387 | Only a subset of keywords may be used on the lines following a | |
388 | Match keyword. Available keywords are AllowAgentForwarding, | |
389 | - AllowTcpForwarding, AuthorizedKeysFile, AuthorizedPrincipalsFile, | |
390 | + AllowTcpForwarding, AuthorizedKeysFile, AuthorizedKeysCommand, | |
391 | + AuthorizedKeysCommandRunAs, AuthorizedPrincipalsFile, | |
392 | Banner, ChrootDirectory, ForceCommand, GatewayPorts, | |
393 | GSSAPIAuthentication, HostbasedAuthentication, | |
394 | HostbasedUsesNameFromPacketOnly, KbdInteractiveAuthentication, | |
395 | diff -up openssh-5.8p1/sshd_config.5.akc openssh-5.8p1/sshd_config.5 | |
396 | --- openssh-5.8p1/sshd_config.5.akc 2011-02-10 13:21:28.000000000 +0100 | |
397 | +++ openssh-5.8p1/sshd_config.5 2011-02-10 13:21:28.000000000 +0100 | |
398 | @@ -703,6 +703,8 @@ Available keywords are | |
399 | .Cm AllowAgentForwarding , | |
400 | .Cm AllowTcpForwarding , | |
401 | .Cm AuthorizedKeysFile , | |
402 | +.Cm AuthorizedKeysCommand , | |
403 | +.Cm AuthorizedKeysCommandRunAs , | |
404 | .Cm AuthorizedPrincipalsFile , | |
405 | .Cm Banner , | |
406 | .Cm ChrootDirectory , | |
407 | @@ -715,6 +717,7 @@ Available keywords are | |
408 | .Cm KerberosAuthentication , | |
409 | .Cm MaxAuthTries , | |
410 | .Cm MaxSessions , | |
411 | +.Cm PubkeyAuthentication , | |
412 | .Cm PasswordAuthentication , | |
413 | .Cm PermitEmptyPasswords , | |
414 | .Cm PermitOpen , | |
415 | @@ -917,6 +920,20 @@ Specifies a list of revoked public keys. | |
416 | Keys listed in this file will be refused for public key authentication. | |
417 | Note that if this file is not readable, then public key authentication will | |
418 | be refused for all users. | |
419 | +.It Cm AuthorizedKeysCommand | |
420 | +Specifies a program to be used for lookup of the user's | |
421 | +public keys. The program will be invoked with its first | |
422 | +argument the name of the user being authorized, and should produce | |
423 | +on standard output AuthorizedKeys lines (see AUTHORIZED_KEYS | |
424 | +in sshd(8)). By default (or when set to the empty string) there is no | |
425 | +AuthorizedKeysCommand run. If the AuthorizedKeysCommand does not successfully | |
426 | +authorize the user, authorization falls through to the | |
427 | +AuthorizedKeysFile. Note that this option has an effect | |
428 | +only with PubkeyAuthentication turned on. | |
429 | +.It Cm AuthorizedKeysCommandRunAs | |
430 | +Specifies the user under whose account the AuthorizedKeysCommand is run. Empty | |
431 | +string (the default value) means the user being authorized is used. | |
432 | +.Dq | |
433 | .It Cm RhostsRSAAuthentication | |
434 | Specifies whether rhosts or /etc/hosts.equiv authentication together | |
435 | with successful RSA host authentication is allowed. | |
436 | diff -up openssh-5.8p1/sshd_config.akc openssh-5.8p1/sshd_config | |
437 | --- openssh-5.8p1/sshd_config.akc 2011-02-10 13:21:28.000000000 +0100 | |
438 | +++ openssh-5.8p1/sshd_config 2011-02-10 13:21:28.000000000 +0100 | |
439 | @@ -46,6 +46,8 @@ SyslogFacility AUTHPRIV | |
440 | #RSAAuthentication yes | |
441 | #PubkeyAuthentication yes | |
442 | #AuthorizedKeysFile .ssh/authorized_keys | |
443 | +#AuthorizedKeysCommand none | |
444 | +#AuthorizedKeysCommandRunAs nobody | |
445 | ||
446 | # For this to work you will also need host keys in /etc/ssh/ssh_known_hosts | |
447 | #RhostsRSAAuthentication no |