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 5822e79e 2023-02-23 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 0ccf3acb 2022-11-16 stsp uidcheck(const char *s, uid_t desired)
81 1963be61 2023-04-14 stsp if (gotd_parseuid(s, &uid) != 0)
83 0ccf3acb 2022-11-16 stsp if (uid != desired)
89 0ccf3acb 2022-11-16 stsp parsegid(const char *s, gid_t *gid)
91 0ccf3acb 2022-11-16 stsp struct group *gr;
92 0ccf3acb 2022-11-16 stsp const char *errstr;
94 0ccf3acb 2022-11-16 stsp if ((gr = getgrnam(s)) != NULL) {
95 0ccf3acb 2022-11-16 stsp *gid = gr->gr_gid;
96 0ccf3acb 2022-11-16 stsp if (*gid == GID_MAX)
100 0ccf3acb 2022-11-16 stsp *gid = strtonum(s, 0, GID_MAX - 1, &errstr);
101 0ccf3acb 2022-11-16 stsp if (errstr)
107 0ccf3acb 2022-11-16 stsp match_identifier(const char *identifier, gid_t *groups, int ngroups,
108 0ccf3acb 2022-11-16 stsp uid_t euid, gid_t egid)
112 0ccf3acb 2022-11-16 stsp if (identifier[0] == ':') {
113 0ccf3acb 2022-11-16 stsp gid_t rgid;
114 0ccf3acb 2022-11-16 stsp if (parsegid(identifier + 1, &rgid) == -1)
116 ddbe612c 2022-11-17 stsp if (rgid == egid)
118 0ccf3acb 2022-11-16 stsp for (i = 0; i < ngroups; i++) {
119 ddbe612c 2022-11-17 stsp if (rgid == groups[i])
122 0ccf3acb 2022-11-16 stsp if (i == ngroups)
124 0ccf3acb 2022-11-16 stsp } else if (uidcheck(identifier, euid) != 0)
130 5e25db14 2022-12-29 stsp static const struct got_error *
131 56624d2b 2023-12-27 stsp auth_check(char **username, struct gotd_access_rule_list *rules,
132 56624d2b 2023-12-27 stsp const char *repo_name, uid_t euid, gid_t egid, int required_auth)
134 0ccf3acb 2022-11-16 stsp struct gotd_access_rule *rule;
135 0ccf3acb 2022-11-16 stsp enum gotd_access access = GOTD_ACCESS_DENIED;
136 ddbe612c 2022-11-17 stsp struct passwd *pw;
137 ddbe612c 2022-11-17 stsp gid_t groups[NGROUPS_MAX];
138 ddbe612c 2022-11-17 stsp int ngroups = NGROUPS_MAX;
140 56624d2b 2023-12-27 stsp *username = NULL;
142 ddbe612c 2022-11-17 stsp pw = getpwuid(euid);
143 e18d071f 2022-11-20 stsp if (pw == NULL) {
145 e18d071f 2022-11-20 stsp return got_error_from_errno("getpwuid");
147 e18d071f 2022-11-20 stsp return got_error_set_errno(EACCES, repo_name);
150 56624d2b 2023-12-27 stsp *username = strdup(pw->pw_name);
151 56624d2b 2023-12-27 stsp if (*username == NULL)
152 56624d2b 2023-12-27 stsp return got_error_from_errno("strdup");
154 ddbe612c 2022-11-17 stsp if (getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups) == -1)
155 ddbe612c 2022-11-17 stsp log_warnx("group membership list truncated");
157 0ccf3acb 2022-11-16 stsp STAILQ_FOREACH(rule, rules, entry) {
158 0ccf3acb 2022-11-16 stsp if (!match_identifier(rule->identifier, groups, ngroups,
159 0ccf3acb 2022-11-16 stsp euid, egid))
162 0ccf3acb 2022-11-16 stsp access = rule->access;
163 0ccf3acb 2022-11-16 stsp if (rule->access == GOTD_ACCESS_PERMITTED &&
164 0ccf3acb 2022-11-16 stsp (rule->authorization & required_auth) != required_auth)
165 0ccf3acb 2022-11-16 stsp access = GOTD_ACCESS_DENIED;
168 0ccf3acb 2022-11-16 stsp if (access == GOTD_ACCESS_DENIED)
169 0ccf3acb 2022-11-16 stsp return got_error_set_errno(EACCES, repo_name);
171 0ccf3acb 2022-11-16 stsp if (access == GOTD_ACCESS_PERMITTED)
172 0ccf3acb 2022-11-16 stsp return NULL;
174 0ccf3acb 2022-11-16 stsp /* should not happen, this would be a bug */
175 0ccf3acb 2022-11-16 stsp return got_error_msg(GOT_ERR_NOT_IMPL, "bad access rule");
178 5e25db14 2022-12-29 stsp static const struct got_error *
179 5e25db14 2022-12-29 stsp recv_authreq(struct imsg *imsg, struct gotd_imsgev *iev)
181 5e25db14 2022-12-29 stsp const struct got_error *err;
182 5e25db14 2022-12-29 stsp struct imsgbuf *ibuf = &iev->ibuf;
183 5e25db14 2022-12-29 stsp struct gotd_imsg_auth iauth;
184 5e25db14 2022-12-29 stsp size_t datalen;
185 365cf0f3 2022-12-29 stsp uid_t euid;
186 365cf0f3 2022-12-29 stsp gid_t egid;
187 56624d2b 2023-12-27 stsp char *username = NULL;
188 56624d2b 2023-12-27 stsp size_t len;
189 56624d2b 2023-12-27 stsp const size_t maxlen = MAX_IMSGSIZE - IMSG_HEADER_SIZE;
191 5e25db14 2022-12-29 stsp log_debug("authentication request received");
193 5e25db14 2022-12-29 stsp datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
194 5e25db14 2022-12-29 stsp if (datalen != sizeof(iauth))
195 5e25db14 2022-12-29 stsp return got_error(GOT_ERR_PRIVSEP_LEN);
197 5e25db14 2022-12-29 stsp memcpy(&iauth, imsg->data, datalen);
199 365cf0f3 2022-12-29 stsp if (imsg->fd == -1)
200 365cf0f3 2022-12-29 stsp return got_error(GOT_ERR_PRIVSEP_NO_FD);
202 365cf0f3 2022-12-29 stsp if (getpeereid(imsg->fd, &euid, &egid) == -1)
203 365cf0f3 2022-12-29 stsp return got_error_from_errno("getpeerid");
205 365cf0f3 2022-12-29 stsp if (iauth.euid != euid)
206 365cf0f3 2022-12-29 stsp return got_error(GOT_ERR_UID);
207 365cf0f3 2022-12-29 stsp if (iauth.egid != egid)
208 365cf0f3 2022-12-29 stsp return got_error(GOT_ERR_GID);
210 365cf0f3 2022-12-29 stsp log_debug("authenticating uid %d gid %d", euid, egid);
212 56624d2b 2023-12-27 stsp err = auth_check(&username, &gotd_auth.repo->rules,
213 56624d2b 2023-12-27 stsp gotd_auth.repo->name, iauth.euid, iauth.egid, iauth.required_auth);
215 5e25db14 2022-12-29 stsp gotd_imsg_send_error(ibuf, PROC_AUTH, iauth.client_id, err);
219 56624d2b 2023-12-27 stsp len = strlen(username);
220 56624d2b 2023-12-27 stsp if (len > maxlen)
221 56624d2b 2023-12-27 stsp len = maxlen;
223 56624d2b 2023-12-27 stsp if (gotd_imsg_compose_event(iev, GOTD_IMSG_ACCESS_GRANTED,
224 56624d2b 2023-12-27 stsp PROC_AUTH, -1, username, len) == -1)
225 56624d2b 2023-12-27 stsp err = got_error_from_errno("imsg compose ACCESS_GRANTED");
227 56624d2b 2023-12-27 stsp free(username);
228 56624d2b 2023-12-27 stsp return err;
231 5e25db14 2022-12-29 stsp static void
232 5e25db14 2022-12-29 stsp auth_dispatch(int fd, short event, void *arg)
234 5e25db14 2022-12-29 stsp const struct got_error *err = NULL;
235 5e25db14 2022-12-29 stsp struct gotd_imsgev *iev = arg;
236 5e25db14 2022-12-29 stsp struct imsgbuf *ibuf = &iev->ibuf;
237 5e25db14 2022-12-29 stsp struct imsg imsg;
239 5e25db14 2022-12-29 stsp int shut = 0;
241 5e25db14 2022-12-29 stsp if (event & EV_READ) {
242 5e25db14 2022-12-29 stsp if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
243 5e25db14 2022-12-29 stsp fatal("imsg_read error");
244 5e25db14 2022-12-29 stsp if (n == 0) /* Connection closed. */
248 5e25db14 2022-12-29 stsp if (event & EV_WRITE) {
249 5e25db14 2022-12-29 stsp n = msgbuf_write(&ibuf->w);
250 5e25db14 2022-12-29 stsp if (n == -1 && errno != EAGAIN)
251 5e25db14 2022-12-29 stsp fatal("msgbuf_write");
252 5e25db14 2022-12-29 stsp if (n == 0) /* Connection closed. */
257 5e25db14 2022-12-29 stsp if ((n = imsg_get(ibuf, &imsg)) == -1)
258 5e25db14 2022-12-29 stsp fatal("%s: imsg_get", __func__);
259 5e25db14 2022-12-29 stsp if (n == 0) /* No more messages. */
262 5e25db14 2022-12-29 stsp switch (imsg.hdr.type) {
263 5e25db14 2022-12-29 stsp case GOTD_IMSG_AUTHENTICATE:
264 5e25db14 2022-12-29 stsp err = recv_authreq(&imsg, iev);
266 2ec74a9e 2023-02-08 op log_warnx("%s", err->msg);
269 2ec74a9e 2023-02-08 op log_debug("unexpected imsg %d", imsg.hdr.type);
273 5e25db14 2022-12-29 stsp imsg_free(&imsg);
276 5e25db14 2022-12-29 stsp if (!shut) {
277 5e25db14 2022-12-29 stsp gotd_imsg_event_add(iev);
279 5e25db14 2022-12-29 stsp /* This pipe is dead. Remove its event handler */
280 5e25db14 2022-12-29 stsp event_del(&iev->ev);
281 5e25db14 2022-12-29 stsp event_loopexit(NULL);
286 5e25db14 2022-12-29 stsp auth_main(const char *title, struct gotd_repolist *repos,
287 5e25db14 2022-12-29 stsp const char *repo_path)
289 5e25db14 2022-12-29 stsp struct gotd_repo *repo = NULL;
290 5e25db14 2022-12-29 stsp struct gotd_imsgev iev;
291 5e25db14 2022-12-29 stsp struct event evsigint, evsigterm, evsighup, evsigusr1;
293 5e25db14 2022-12-29 stsp gotd_auth.title = title;
294 5e25db14 2022-12-29 stsp gotd_auth.pid = getpid();
295 5e25db14 2022-12-29 stsp TAILQ_FOREACH(repo, repos, entry) {
296 5e25db14 2022-12-29 stsp if (got_path_cmp(repo->path, repo_path,
297 5e25db14 2022-12-29 stsp strlen(repo->path), strlen(repo_path)) == 0)
300 5e25db14 2022-12-29 stsp if (repo == NULL)
301 5e25db14 2022-12-29 stsp fatalx("repository %s not found in config", repo_path);
302 5e25db14 2022-12-29 stsp gotd_auth.repo = repo;
304 5e25db14 2022-12-29 stsp signal_set(&evsigint, SIGINT, auth_sighdlr, NULL);
305 5e25db14 2022-12-29 stsp signal_set(&evsigterm, SIGTERM, auth_sighdlr, NULL);
306 5e25db14 2022-12-29 stsp signal_set(&evsighup, SIGHUP, auth_sighdlr, NULL);
307 5e25db14 2022-12-29 stsp signal_set(&evsigusr1, SIGUSR1, auth_sighdlr, NULL);
308 5e25db14 2022-12-29 stsp signal(SIGPIPE, SIG_IGN);
310 5e25db14 2022-12-29 stsp signal_add(&evsigint, NULL);
311 5e25db14 2022-12-29 stsp signal_add(&evsigterm, NULL);
312 5e25db14 2022-12-29 stsp signal_add(&evsighup, NULL);
313 5e25db14 2022-12-29 stsp signal_add(&evsigusr1, NULL);
315 5e25db14 2022-12-29 stsp imsg_init(&iev.ibuf, GOTD_FILENO_MSG_PIPE);
316 5e25db14 2022-12-29 stsp iev.handler = auth_dispatch;
317 5e25db14 2022-12-29 stsp iev.events = EV_READ;
318 5e25db14 2022-12-29 stsp iev.handler_arg = NULL;
319 5e25db14 2022-12-29 stsp event_set(&iev.ev, iev.ibuf.fd, EV_READ, auth_dispatch, &iev);
320 5e25db14 2022-12-29 stsp if (event_add(&iev.ev, NULL) == -1)
321 5e25db14 2022-12-29 stsp fatalx("event add");
323 5e25db14 2022-12-29 stsp event_dispatch();
325 5e25db14 2022-12-29 stsp auth_shutdown();
328 5e25db14 2022-12-29 stsp static void
329 5e25db14 2022-12-29 stsp auth_shutdown(void)
331 2ec74a9e 2023-02-08 op log_debug("shutting down");
