2 0ccf3acb 2022-11-16 stsp * Copyright (c) 2022 Stefan Sperling <stsp@openbsd.org>
3 0ccf3acb 2022-11-16 stsp * Copyright (c) 2015 Ted Unangst <tedu@openbsd.org>
5 0ccf3acb 2022-11-16 stsp * Permission to use, copy, modify, and distribute this software for any
6 0ccf3acb 2022-11-16 stsp * purpose with or without fee is hereby granted, provided that the above
7 0ccf3acb 2022-11-16 stsp * copyright notice and this permission notice appear in all copies.
9 0ccf3acb 2022-11-16 stsp * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 0ccf3acb 2022-11-16 stsp * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 0ccf3acb 2022-11-16 stsp * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 0ccf3acb 2022-11-16 stsp * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 0ccf3acb 2022-11-16 stsp * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 0ccf3acb 2022-11-16 stsp * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 0ccf3acb 2022-11-16 stsp * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 0ccf3acb 2022-11-16 stsp #include <sys/types.h>
19 365cf0f3 2022-12-29 stsp #include <sys/socket.h>
20 0ccf3acb 2022-11-16 stsp #include <sys/queue.h>
21 0ccf3acb 2022-11-16 stsp #include <sys/uio.h>
23 0ccf3acb 2022-11-16 stsp #include <errno.h>
24 0ccf3acb 2022-11-16 stsp #include <event.h>
25 0ccf3acb 2022-11-16 stsp #include <limits.h>
26 0ccf3acb 2022-11-16 stsp #include <pwd.h>
27 0ccf3acb 2022-11-16 stsp #include <grp.h>
28 0ccf3acb 2022-11-16 stsp #include <sha1.h>
29 69c6accf 2023-02-04 op #include <sha2.h>
30 5e25db14 2022-12-29 stsp #include <signal.h>
31 0ccf3acb 2022-11-16 stsp #include <stdint.h>
32 0ccf3acb 2022-11-16 stsp #include <stdio.h>
33 0ccf3acb 2022-11-16 stsp #include <stdlib.h>
34 5e25db14 2022-12-29 stsp #include <string.h>
35 0ccf3acb 2022-11-16 stsp #include <imsg.h>
36 ddbe612c 2022-11-17 stsp #include <unistd.h>
38 0ccf3acb 2022-11-16 stsp #include "got_error.h"
39 5e25db14 2022-12-29 stsp #include "got_path.h"
41 0ccf3acb 2022-11-16 stsp #include "gotd.h"
42 ddbe612c 2022-11-17 stsp #include "log.h"
43 0ccf3acb 2022-11-16 stsp #include "auth.h"
45 5e25db14 2022-12-29 stsp static struct gotd_auth {
47 5e25db14 2022-12-29 stsp const char *title;
48 5e25db14 2022-12-29 stsp struct gotd_repo *repo;
49 5e25db14 2022-12-29 stsp } gotd_auth;
51 5e25db14 2022-12-29 stsp static void auth_shutdown(void);
54 5e25db14 2022-12-29 stsp auth_sighdlr(int sig, short event, void *arg)
57 5e25db14 2022-12-29 stsp * Normal signal handler rules don't apply because libevent
58 5e25db14 2022-12-29 stsp * decouples for us.
61 5e25db14 2022-12-29 stsp switch (sig) {
62 5e25db14 2022-12-29 stsp case SIGHUP:
64 5e25db14 2022-12-29 stsp case SIGUSR1:
66 5e25db14 2022-12-29 stsp case SIGTERM:
67 5e25db14 2022-12-29 stsp case SIGINT:
68 5e25db14 2022-12-29 stsp auth_shutdown();
69 5e25db14 2022-12-29 stsp /* NOTREACHED */
72 5e25db14 2022-12-29 stsp fatalx("unexpected signal");
77 40b85cca 2023-01-03 stsp gotd_auth_parseuid(const char *s, uid_t *uid)
79 0ccf3acb 2022-11-16 stsp struct passwd *pw;
80 0ccf3acb 2022-11-16 stsp const char *errstr;
82 0ccf3acb 2022-11-16 stsp if ((pw = getpwnam(s)) != NULL) {
83 0ccf3acb 2022-11-16 stsp *uid = pw->pw_uid;
84 0ccf3acb 2022-11-16 stsp if (*uid == UID_MAX)
88 0ccf3acb 2022-11-16 stsp *uid = strtonum(s, 0, UID_MAX - 1, &errstr);
95 0ccf3acb 2022-11-16 stsp uidcheck(const char *s, uid_t desired)
99 40b85cca 2023-01-03 stsp if (gotd_auth_parseuid(s, &uid) != 0)
101 0ccf3acb 2022-11-16 stsp if (uid != desired)
107 0ccf3acb 2022-11-16 stsp parsegid(const char *s, gid_t *gid)
109 0ccf3acb 2022-11-16 stsp struct group *gr;
110 0ccf3acb 2022-11-16 stsp const char *errstr;
112 0ccf3acb 2022-11-16 stsp if ((gr = getgrnam(s)) != NULL) {
113 0ccf3acb 2022-11-16 stsp *gid = gr->gr_gid;
114 0ccf3acb 2022-11-16 stsp if (*gid == GID_MAX)
118 0ccf3acb 2022-11-16 stsp *gid = strtonum(s, 0, GID_MAX - 1, &errstr);
119 0ccf3acb 2022-11-16 stsp if (errstr)
125 0ccf3acb 2022-11-16 stsp match_identifier(const char *identifier, gid_t *groups, int ngroups,
126 0ccf3acb 2022-11-16 stsp uid_t euid, gid_t egid)
130 0ccf3acb 2022-11-16 stsp if (identifier[0] == ':') {
131 0ccf3acb 2022-11-16 stsp gid_t rgid;
132 0ccf3acb 2022-11-16 stsp if (parsegid(identifier + 1, &rgid) == -1)
134 ddbe612c 2022-11-17 stsp if (rgid == egid)
136 0ccf3acb 2022-11-16 stsp for (i = 0; i < ngroups; i++) {
137 ddbe612c 2022-11-17 stsp if (rgid == groups[i])
140 0ccf3acb 2022-11-16 stsp if (i == ngroups)
142 0ccf3acb 2022-11-16 stsp } else if (uidcheck(identifier, euid) != 0)
148 5e25db14 2022-12-29 stsp static const struct got_error *
149 5e25db14 2022-12-29 stsp auth_check(struct gotd_access_rule_list *rules, const char *repo_name,
150 ddbe612c 2022-11-17 stsp uid_t euid, gid_t egid, int required_auth)
152 0ccf3acb 2022-11-16 stsp struct gotd_access_rule *rule;
153 0ccf3acb 2022-11-16 stsp enum gotd_access access = GOTD_ACCESS_DENIED;
154 ddbe612c 2022-11-17 stsp struct passwd *pw;
155 ddbe612c 2022-11-17 stsp gid_t groups[NGROUPS_MAX];
156 ddbe612c 2022-11-17 stsp int ngroups = NGROUPS_MAX;
158 ddbe612c 2022-11-17 stsp pw = getpwuid(euid);
159 e18d071f 2022-11-20 stsp if (pw == NULL) {
161 e18d071f 2022-11-20 stsp return got_error_from_errno("getpwuid");
163 e18d071f 2022-11-20 stsp return got_error_set_errno(EACCES, repo_name);
166 ddbe612c 2022-11-17 stsp if (getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups) == -1)
167 ddbe612c 2022-11-17 stsp log_warnx("group membership list truncated");
169 0ccf3acb 2022-11-16 stsp STAILQ_FOREACH(rule, rules, entry) {
170 0ccf3acb 2022-11-16 stsp if (!match_identifier(rule->identifier, groups, ngroups,
171 0ccf3acb 2022-11-16 stsp euid, egid))
174 0ccf3acb 2022-11-16 stsp access = rule->access;
175 0ccf3acb 2022-11-16 stsp if (rule->access == GOTD_ACCESS_PERMITTED &&
176 0ccf3acb 2022-11-16 stsp (rule->authorization & required_auth) != required_auth)
177 0ccf3acb 2022-11-16 stsp access = GOTD_ACCESS_DENIED;
180 0ccf3acb 2022-11-16 stsp if (access == GOTD_ACCESS_DENIED)
181 0ccf3acb 2022-11-16 stsp return got_error_set_errno(EACCES, repo_name);
183 0ccf3acb 2022-11-16 stsp if (access == GOTD_ACCESS_PERMITTED)
184 0ccf3acb 2022-11-16 stsp return NULL;
186 0ccf3acb 2022-11-16 stsp /* should not happen, this would be a bug */
187 0ccf3acb 2022-11-16 stsp return got_error_msg(GOT_ERR_NOT_IMPL, "bad access rule");
190 5e25db14 2022-12-29 stsp static const struct got_error *
191 5e25db14 2022-12-29 stsp recv_authreq(struct imsg *imsg, struct gotd_imsgev *iev)
193 5e25db14 2022-12-29 stsp const struct got_error *err;
194 5e25db14 2022-12-29 stsp struct imsgbuf *ibuf = &iev->ibuf;
195 5e25db14 2022-12-29 stsp struct gotd_imsg_auth iauth;
196 5e25db14 2022-12-29 stsp size_t datalen;
197 365cf0f3 2022-12-29 stsp uid_t euid;
198 365cf0f3 2022-12-29 stsp gid_t egid;
200 5e25db14 2022-12-29 stsp log_debug("authentication request received");
202 5e25db14 2022-12-29 stsp datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
203 5e25db14 2022-12-29 stsp if (datalen != sizeof(iauth))
204 5e25db14 2022-12-29 stsp return got_error(GOT_ERR_PRIVSEP_LEN);
206 5e25db14 2022-12-29 stsp memcpy(&iauth, imsg->data, datalen);
208 365cf0f3 2022-12-29 stsp if (imsg->fd == -1)
209 365cf0f3 2022-12-29 stsp return got_error(GOT_ERR_PRIVSEP_NO_FD);
211 365cf0f3 2022-12-29 stsp if (getpeereid(imsg->fd, &euid, &egid) == -1)
212 365cf0f3 2022-12-29 stsp return got_error_from_errno("getpeerid");
214 365cf0f3 2022-12-29 stsp if (iauth.euid != euid)
215 365cf0f3 2022-12-29 stsp return got_error(GOT_ERR_UID);
216 365cf0f3 2022-12-29 stsp if (iauth.egid != egid)
217 365cf0f3 2022-12-29 stsp return got_error(GOT_ERR_GID);
219 365cf0f3 2022-12-29 stsp log_debug("authenticating uid %d gid %d", euid, egid);
221 5e25db14 2022-12-29 stsp err = auth_check(&gotd_auth.repo->rules, gotd_auth.repo->name,
222 5e25db14 2022-12-29 stsp iauth.euid, iauth.egid, iauth.required_auth);
224 5e25db14 2022-12-29 stsp gotd_imsg_send_error(ibuf, PROC_AUTH, iauth.client_id, err);
225 5e25db14 2022-12-29 stsp return err;
228 5e25db14 2022-12-29 stsp if (gotd_imsg_compose_event(iev, GOTD_IMSG_ACCESS_GRANTED,
229 5e25db14 2022-12-29 stsp PROC_AUTH, -1, NULL, 0) == -1)
230 5e25db14 2022-12-29 stsp return got_error_from_errno("imsg compose ACCESS_GRANTED");
232 5e25db14 2022-12-29 stsp return NULL;
235 5e25db14 2022-12-29 stsp static void
236 5e25db14 2022-12-29 stsp auth_dispatch(int fd, short event, void *arg)
238 5e25db14 2022-12-29 stsp const struct got_error *err = NULL;
239 5e25db14 2022-12-29 stsp struct gotd_imsgev *iev = arg;
240 5e25db14 2022-12-29 stsp struct imsgbuf *ibuf = &iev->ibuf;
241 5e25db14 2022-12-29 stsp struct imsg imsg;
243 5e25db14 2022-12-29 stsp int shut = 0;
245 5e25db14 2022-12-29 stsp if (event & EV_READ) {
246 5e25db14 2022-12-29 stsp if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
247 5e25db14 2022-12-29 stsp fatal("imsg_read error");
248 5e25db14 2022-12-29 stsp if (n == 0) /* Connection closed. */
252 5e25db14 2022-12-29 stsp if (event & EV_WRITE) {
253 5e25db14 2022-12-29 stsp n = msgbuf_write(&ibuf->w);
254 5e25db14 2022-12-29 stsp if (n == -1 && errno != EAGAIN)
255 5e25db14 2022-12-29 stsp fatal("msgbuf_write");
256 5e25db14 2022-12-29 stsp if (n == 0) /* Connection closed. */
261 5e25db14 2022-12-29 stsp if ((n = imsg_get(ibuf, &imsg)) == -1)
262 5e25db14 2022-12-29 stsp fatal("%s: imsg_get", __func__);
263 5e25db14 2022-12-29 stsp if (n == 0) /* No more messages. */
266 5e25db14 2022-12-29 stsp switch (imsg.hdr.type) {
267 5e25db14 2022-12-29 stsp case GOTD_IMSG_AUTHENTICATE:
268 5e25db14 2022-12-29 stsp err = recv_authreq(&imsg, iev);
270 5e25db14 2022-12-29 stsp log_warnx("%s: %s", gotd_auth.title, err->msg);
273 5e25db14 2022-12-29 stsp log_debug("%s: unexpected imsg %d", gotd_auth.title,
274 5e25db14 2022-12-29 stsp imsg.hdr.type);
278 5e25db14 2022-12-29 stsp imsg_free(&imsg);
281 5e25db14 2022-12-29 stsp if (!shut) {
282 5e25db14 2022-12-29 stsp gotd_imsg_event_add(iev);
284 5e25db14 2022-12-29 stsp /* This pipe is dead. Remove its event handler */
285 5e25db14 2022-12-29 stsp event_del(&iev->ev);
286 5e25db14 2022-12-29 stsp event_loopexit(NULL);
291 5e25db14 2022-12-29 stsp auth_main(const char *title, struct gotd_repolist *repos,
292 5e25db14 2022-12-29 stsp const char *repo_path)
294 5e25db14 2022-12-29 stsp struct gotd_repo *repo = NULL;
295 5e25db14 2022-12-29 stsp struct gotd_imsgev iev;
296 5e25db14 2022-12-29 stsp struct event evsigint, evsigterm, evsighup, evsigusr1;
298 5e25db14 2022-12-29 stsp gotd_auth.title = title;
299 5e25db14 2022-12-29 stsp gotd_auth.pid = getpid();
300 5e25db14 2022-12-29 stsp TAILQ_FOREACH(repo, repos, entry) {
301 5e25db14 2022-12-29 stsp if (got_path_cmp(repo->path, repo_path,
302 5e25db14 2022-12-29 stsp strlen(repo->path), strlen(repo_path)) == 0)
305 5e25db14 2022-12-29 stsp if (repo == NULL)
306 5e25db14 2022-12-29 stsp fatalx("repository %s not found in config", repo_path);
307 5e25db14 2022-12-29 stsp gotd_auth.repo = repo;
309 5e25db14 2022-12-29 stsp signal_set(&evsigint, SIGINT, auth_sighdlr, NULL);
310 5e25db14 2022-12-29 stsp signal_set(&evsigterm, SIGTERM, auth_sighdlr, NULL);
311 5e25db14 2022-12-29 stsp signal_set(&evsighup, SIGHUP, auth_sighdlr, NULL);
312 5e25db14 2022-12-29 stsp signal_set(&evsigusr1, SIGUSR1, auth_sighdlr, NULL);
313 5e25db14 2022-12-29 stsp signal(SIGPIPE, SIG_IGN);
315 5e25db14 2022-12-29 stsp signal_add(&evsigint, NULL);
316 5e25db14 2022-12-29 stsp signal_add(&evsigterm, NULL);
317 5e25db14 2022-12-29 stsp signal_add(&evsighup, NULL);
318 5e25db14 2022-12-29 stsp signal_add(&evsigusr1, NULL);
320 5e25db14 2022-12-29 stsp imsg_init(&iev.ibuf, GOTD_FILENO_MSG_PIPE);
321 5e25db14 2022-12-29 stsp iev.handler = auth_dispatch;
322 5e25db14 2022-12-29 stsp iev.events = EV_READ;
323 5e25db14 2022-12-29 stsp iev.handler_arg = NULL;
324 5e25db14 2022-12-29 stsp event_set(&iev.ev, iev.ibuf.fd, EV_READ, auth_dispatch, &iev);
325 5e25db14 2022-12-29 stsp if (event_add(&iev.ev, NULL) == -1)
326 5e25db14 2022-12-29 stsp fatalx("event add");
328 5e25db14 2022-12-29 stsp event_dispatch();
330 5e25db14 2022-12-29 stsp auth_shutdown();
333 5e25db14 2022-12-29 stsp static void
334 5e25db14 2022-12-29 stsp auth_shutdown(void)
336 5e25db14 2022-12-29 stsp log_debug("%s: shutting down", gotd_auth.title);
