2 729a7e24 2022-11-17 thomas * Copyright (c) 2022 Stefan Sperling <stsp@openbsd.org>
3 729a7e24 2022-11-17 thomas * Copyright (c) 2015 Ted Unangst <tedu@openbsd.org>
5 729a7e24 2022-11-17 thomas * Permission to use, copy, modify, and distribute this software for any
6 729a7e24 2022-11-17 thomas * purpose with or without fee is hereby granted, provided that the above
7 729a7e24 2022-11-17 thomas * copyright notice and this permission notice appear in all copies.
9 729a7e24 2022-11-17 thomas * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 729a7e24 2022-11-17 thomas * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 729a7e24 2022-11-17 thomas * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 729a7e24 2022-11-17 thomas * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 729a7e24 2022-11-17 thomas * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 729a7e24 2022-11-17 thomas * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 729a7e24 2022-11-17 thomas * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 4efc8dcb 2023-08-29 thomas #include "got_compat.h"
20 729a7e24 2022-11-17 thomas #include <sys/types.h>
21 0bcde4c8 2022-12-30 thomas #include <sys/socket.h>
22 729a7e24 2022-11-17 thomas #include <sys/queue.h>
23 729a7e24 2022-11-17 thomas #include <sys/uio.h>
25 729a7e24 2022-11-17 thomas #include <errno.h>
26 729a7e24 2022-11-17 thomas #include <event.h>
27 729a7e24 2022-11-17 thomas #include <limits.h>
28 729a7e24 2022-11-17 thomas #include <pwd.h>
29 729a7e24 2022-11-17 thomas #include <grp.h>
30 c669c489 2022-12-30 thomas #include <signal.h>
31 729a7e24 2022-11-17 thomas #include <stdint.h>
32 729a7e24 2022-11-17 thomas #include <stdio.h>
33 729a7e24 2022-11-17 thomas #include <stdlib.h>
34 c669c489 2022-12-30 thomas #include <string.h>
35 729a7e24 2022-11-17 thomas #include <imsg.h>
36 ff260661 2022-11-17 thomas #include <unistd.h>
38 729a7e24 2022-11-17 thomas #include "got_error.h"
39 c669c489 2022-12-30 thomas #include "got_path.h"
41 729a7e24 2022-11-17 thomas #include "gotd.h"
42 ff260661 2022-11-17 thomas #include "log.h"
43 729a7e24 2022-11-17 thomas #include "auth.h"
45 c669c489 2022-12-30 thomas static struct gotd_auth {
46 c669c489 2022-12-30 thomas pid_t pid;
47 c669c489 2022-12-30 thomas const char *title;
48 c669c489 2022-12-30 thomas struct gotd_repo *repo;
49 c669c489 2022-12-30 thomas } gotd_auth;
51 c669c489 2022-12-30 thomas static void auth_shutdown(void);
53 c669c489 2022-12-30 thomas static void
54 c669c489 2022-12-30 thomas auth_sighdlr(int sig, short event, void *arg)
57 c669c489 2022-12-30 thomas * Normal signal handler rules don't apply because libevent
58 c669c489 2022-12-30 thomas * decouples for us.
61 c669c489 2022-12-30 thomas switch (sig) {
62 c669c489 2022-12-30 thomas case SIGHUP:
64 c669c489 2022-12-30 thomas case SIGUSR1:
66 c669c489 2022-12-30 thomas case SIGTERM:
67 c669c489 2022-12-30 thomas case SIGINT:
68 c669c489 2022-12-30 thomas auth_shutdown();
69 c669c489 2022-12-30 thomas /* NOTREACHED */
72 c669c489 2022-12-30 thomas fatalx("unexpected signal");
76 729a7e24 2022-11-17 thomas static int
77 729a7e24 2022-11-17 thomas uidcheck(const char *s, uid_t desired)
79 729a7e24 2022-11-17 thomas uid_t uid;
81 48488136 2023-04-22 thomas if (gotd_parseuid(s, &uid) != 0)
82 729a7e24 2022-11-17 thomas return -1;
83 729a7e24 2022-11-17 thomas if (uid != desired)
84 729a7e24 2022-11-17 thomas return -1;
88 729a7e24 2022-11-17 thomas static int
89 729a7e24 2022-11-17 thomas parsegid(const char *s, gid_t *gid)
91 729a7e24 2022-11-17 thomas struct group *gr;
92 729a7e24 2022-11-17 thomas const char *errstr;
94 729a7e24 2022-11-17 thomas if ((gr = getgrnam(s)) != NULL) {
95 729a7e24 2022-11-17 thomas *gid = gr->gr_gid;
96 729a7e24 2022-11-17 thomas if (*gid == GID_MAX)
97 729a7e24 2022-11-17 thomas return -1;
100 729a7e24 2022-11-17 thomas *gid = strtonum(s, 0, GID_MAX - 1, &errstr);
101 729a7e24 2022-11-17 thomas if (errstr)
102 729a7e24 2022-11-17 thomas return -1;
103 729a7e24 2022-11-17 thomas return 0;
106 729a7e24 2022-11-17 thomas static int
107 729a7e24 2022-11-17 thomas match_identifier(const char *identifier, gid_t *groups, int ngroups,
108 729a7e24 2022-11-17 thomas uid_t euid, gid_t egid)
112 729a7e24 2022-11-17 thomas if (identifier[0] == ':') {
113 729a7e24 2022-11-17 thomas gid_t rgid;
114 729a7e24 2022-11-17 thomas if (parsegid(identifier + 1, &rgid) == -1)
115 729a7e24 2022-11-17 thomas return 0;
116 ff260661 2022-11-17 thomas if (rgid == egid)
117 ff260661 2022-11-17 thomas return 1;
118 729a7e24 2022-11-17 thomas for (i = 0; i < ngroups; i++) {
119 ff260661 2022-11-17 thomas if (rgid == groups[i])
122 729a7e24 2022-11-17 thomas if (i == ngroups)
123 729a7e24 2022-11-17 thomas return 0;
124 729a7e24 2022-11-17 thomas } else if (uidcheck(identifier, euid) != 0)
125 729a7e24 2022-11-17 thomas return 0;
127 729a7e24 2022-11-17 thomas return 1;
130 c669c489 2022-12-30 thomas static const struct got_error *
131 bb12a506 2023-12-30 thomas auth_check(char **username, struct gotd_access_rule_list *rules,
132 bb12a506 2023-12-30 thomas const char *repo_name, uid_t euid, gid_t egid, int required_auth)
134 729a7e24 2022-11-17 thomas struct gotd_access_rule *rule;
135 729a7e24 2022-11-17 thomas enum gotd_access access = GOTD_ACCESS_DENIED;
136 ff260661 2022-11-17 thomas struct passwd *pw;
137 ff260661 2022-11-17 thomas gid_t groups[NGROUPS_MAX];
138 ff260661 2022-11-17 thomas int ngroups = NGROUPS_MAX;
140 bb12a506 2023-12-30 thomas *username = NULL;
142 ff260661 2022-11-17 thomas pw = getpwuid(euid);
143 9928b132 2022-11-20 thomas if (pw == NULL) {
144 9928b132 2022-11-20 thomas if (errno)
145 9928b132 2022-11-20 thomas return got_error_from_errno("getpwuid");
147 9928b132 2022-11-20 thomas return got_error_set_errno(EACCES, repo_name);
150 bb12a506 2023-12-30 thomas *username = strdup(pw->pw_name);
151 bb12a506 2023-12-30 thomas if (*username == NULL)
152 bb12a506 2023-12-30 thomas return got_error_from_errno("strdup");
154 ff260661 2022-11-17 thomas if (getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups) == -1)
155 ff260661 2022-11-17 thomas log_warnx("group membership list truncated");
157 729a7e24 2022-11-17 thomas STAILQ_FOREACH(rule, rules, entry) {
158 729a7e24 2022-11-17 thomas if (!match_identifier(rule->identifier, groups, ngroups,
159 729a7e24 2022-11-17 thomas euid, egid))
160 729a7e24 2022-11-17 thomas continue;
162 729a7e24 2022-11-17 thomas access = rule->access;
163 729a7e24 2022-11-17 thomas if (rule->access == GOTD_ACCESS_PERMITTED &&
164 729a7e24 2022-11-17 thomas (rule->authorization & required_auth) != required_auth)
165 729a7e24 2022-11-17 thomas access = GOTD_ACCESS_DENIED;
168 729a7e24 2022-11-17 thomas if (access == GOTD_ACCESS_DENIED)
169 729a7e24 2022-11-17 thomas return got_error_set_errno(EACCES, repo_name);
171 729a7e24 2022-11-17 thomas if (access == GOTD_ACCESS_PERMITTED)
172 729a7e24 2022-11-17 thomas return NULL;
174 729a7e24 2022-11-17 thomas /* should not happen, this would be a bug */
175 729a7e24 2022-11-17 thomas return got_error_msg(GOT_ERR_NOT_IMPL, "bad access rule");
178 c669c489 2022-12-30 thomas static const struct got_error *
179 c669c489 2022-12-30 thomas recv_authreq(struct imsg *imsg, struct gotd_imsgev *iev)
181 c669c489 2022-12-30 thomas const struct got_error *err;
182 c669c489 2022-12-30 thomas struct imsgbuf *ibuf = &iev->ibuf;
183 c669c489 2022-12-30 thomas struct gotd_imsg_auth iauth;
184 c669c489 2022-12-30 thomas size_t datalen;
185 0bcde4c8 2022-12-30 thomas uid_t euid;
186 0bcde4c8 2022-12-30 thomas gid_t egid;
187 bb12a506 2023-12-30 thomas char *username = NULL;
188 bb12a506 2023-12-30 thomas size_t len;
189 bb12a506 2023-12-30 thomas const size_t maxlen = MAX_IMSGSIZE - IMSG_HEADER_SIZE;
190 3d97effa 2024-01-31 thomas int fd = -1;
192 c669c489 2022-12-30 thomas log_debug("authentication request received");
194 c669c489 2022-12-30 thomas datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
195 c669c489 2022-12-30 thomas if (datalen != sizeof(iauth))
196 c669c489 2022-12-30 thomas return got_error(GOT_ERR_PRIVSEP_LEN);
198 c669c489 2022-12-30 thomas memcpy(&iauth, imsg->data, datalen);
200 3d97effa 2024-01-31 thomas fd = imsg_get_fd(imsg);
201 3d97effa 2024-01-31 thomas if (fd == -1)
202 0bcde4c8 2022-12-30 thomas return got_error(GOT_ERR_PRIVSEP_NO_FD);
204 3d97effa 2024-01-31 thomas if (getpeereid(fd, &euid, &egid) == -1)
205 0bcde4c8 2022-12-30 thomas return got_error_from_errno("getpeerid");
207 0bcde4c8 2022-12-30 thomas if (iauth.euid != euid)
208 0bcde4c8 2022-12-30 thomas return got_error(GOT_ERR_UID);
209 0bcde4c8 2022-12-30 thomas if (iauth.egid != egid)
210 0bcde4c8 2022-12-30 thomas return got_error(GOT_ERR_GID);
212 0bcde4c8 2022-12-30 thomas log_debug("authenticating uid %d gid %d", euid, egid);
214 bb12a506 2023-12-30 thomas err = auth_check(&username, &gotd_auth.repo->rules,
215 bb12a506 2023-12-30 thomas gotd_auth.repo->name, iauth.euid, iauth.egid, iauth.required_auth);
216 c669c489 2022-12-30 thomas if (err) {
217 c669c489 2022-12-30 thomas gotd_imsg_send_error(ibuf, PROC_AUTH, iauth.client_id, err);
218 bb12a506 2023-12-30 thomas goto done;
221 bb12a506 2023-12-30 thomas len = strlen(username);
222 bb12a506 2023-12-30 thomas if (len > maxlen)
223 bb12a506 2023-12-30 thomas len = maxlen;
225 bb12a506 2023-12-30 thomas if (gotd_imsg_compose_event(iev, GOTD_IMSG_ACCESS_GRANTED,
226 bb12a506 2023-12-30 thomas PROC_AUTH, -1, username, len) == -1)
227 bb12a506 2023-12-30 thomas err = got_error_from_errno("imsg compose ACCESS_GRANTED");
229 bb12a506 2023-12-30 thomas free(username);
230 bb12a506 2023-12-30 thomas return err;
233 c669c489 2022-12-30 thomas static void
234 c669c489 2022-12-30 thomas auth_dispatch(int fd, short event, void *arg)
236 c669c489 2022-12-30 thomas const struct got_error *err = NULL;
237 c669c489 2022-12-30 thomas struct gotd_imsgev *iev = arg;
238 c669c489 2022-12-30 thomas struct imsgbuf *ibuf = &iev->ibuf;
239 c669c489 2022-12-30 thomas struct imsg imsg;
240 c669c489 2022-12-30 thomas ssize_t n;
241 c669c489 2022-12-30 thomas int shut = 0;
243 c669c489 2022-12-30 thomas if (event & EV_READ) {
244 c669c489 2022-12-30 thomas if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
245 c669c489 2022-12-30 thomas fatal("imsg_read error");
246 c669c489 2022-12-30 thomas if (n == 0) /* Connection closed. */
247 c669c489 2022-12-30 thomas shut = 1;
250 c669c489 2022-12-30 thomas if (event & EV_WRITE) {
251 c669c489 2022-12-30 thomas n = msgbuf_write(&ibuf->w);
252 c669c489 2022-12-30 thomas if (n == -1 && errno != EAGAIN)
253 c669c489 2022-12-30 thomas fatal("msgbuf_write");
254 c669c489 2022-12-30 thomas if (n == 0) /* Connection closed. */
255 c669c489 2022-12-30 thomas shut = 1;
258 c669c489 2022-12-30 thomas for (;;) {
259 c669c489 2022-12-30 thomas if ((n = imsg_get(ibuf, &imsg)) == -1)
260 c669c489 2022-12-30 thomas fatal("%s: imsg_get", __func__);
261 c669c489 2022-12-30 thomas if (n == 0) /* No more messages. */
264 c669c489 2022-12-30 thomas switch (imsg.hdr.type) {
265 c669c489 2022-12-30 thomas case GOTD_IMSG_AUTHENTICATE:
266 c669c489 2022-12-30 thomas err = recv_authreq(&imsg, iev);
268 5330ab76 2023-02-17 thomas log_warnx("%s", err->msg);
271 5330ab76 2023-02-17 thomas log_debug("unexpected imsg %d", imsg.hdr.type);
275 c669c489 2022-12-30 thomas imsg_free(&imsg);
278 c669c489 2022-12-30 thomas if (!shut) {
279 c669c489 2022-12-30 thomas gotd_imsg_event_add(iev);
281 c669c489 2022-12-30 thomas /* This pipe is dead. Remove its event handler */
282 c669c489 2022-12-30 thomas event_del(&iev->ev);
283 c669c489 2022-12-30 thomas event_loopexit(NULL);
288 c669c489 2022-12-30 thomas auth_main(const char *title, struct gotd_repolist *repos,
289 c669c489 2022-12-30 thomas const char *repo_path)
291 c669c489 2022-12-30 thomas struct gotd_repo *repo = NULL;
292 c669c489 2022-12-30 thomas struct gotd_imsgev iev;
293 c669c489 2022-12-30 thomas struct event evsigint, evsigterm, evsighup, evsigusr1;
295 c669c489 2022-12-30 thomas gotd_auth.title = title;
296 c669c489 2022-12-30 thomas gotd_auth.pid = getpid();
297 c669c489 2022-12-30 thomas TAILQ_FOREACH(repo, repos, entry) {
298 c669c489 2022-12-30 thomas if (got_path_cmp(repo->path, repo_path,
299 c669c489 2022-12-30 thomas strlen(repo->path), strlen(repo_path)) == 0)
302 c669c489 2022-12-30 thomas if (repo == NULL)
303 c669c489 2022-12-30 thomas fatalx("repository %s not found in config", repo_path);
304 c669c489 2022-12-30 thomas gotd_auth.repo = repo;
306 c669c489 2022-12-30 thomas signal_set(&evsigint, SIGINT, auth_sighdlr, NULL);
307 c669c489 2022-12-30 thomas signal_set(&evsigterm, SIGTERM, auth_sighdlr, NULL);
308 c669c489 2022-12-30 thomas signal_set(&evsighup, SIGHUP, auth_sighdlr, NULL);
309 c669c489 2022-12-30 thomas signal_set(&evsigusr1, SIGUSR1, auth_sighdlr, NULL);
310 c669c489 2022-12-30 thomas signal(SIGPIPE, SIG_IGN);
312 c669c489 2022-12-30 thomas signal_add(&evsigint, NULL);
313 c669c489 2022-12-30 thomas signal_add(&evsigterm, NULL);
314 c669c489 2022-12-30 thomas signal_add(&evsighup, NULL);
315 c669c489 2022-12-30 thomas signal_add(&evsigusr1, NULL);
317 c669c489 2022-12-30 thomas imsg_init(&iev.ibuf, GOTD_FILENO_MSG_PIPE);
318 c669c489 2022-12-30 thomas iev.handler = auth_dispatch;
319 c669c489 2022-12-30 thomas iev.events = EV_READ;
320 c669c489 2022-12-30 thomas iev.handler_arg = NULL;
321 c669c489 2022-12-30 thomas event_set(&iev.ev, iev.ibuf.fd, EV_READ, auth_dispatch, &iev);
322 c669c489 2022-12-30 thomas if (event_add(&iev.ev, NULL) == -1)
323 c669c489 2022-12-30 thomas fatalx("event add");
325 c669c489 2022-12-30 thomas event_dispatch();
327 c669c489 2022-12-30 thomas auth_shutdown();
330 c669c489 2022-12-30 thomas static void
331 c669c489 2022-12-30 thomas auth_shutdown(void)
333 b1a47061 2024-03-30 thomas log_debug("%s: shutting down", gotd_auth.title);
