2.54
utils.c
1/* snac - A simple, minimalistic ActivityPub instance */
2/* copyright (c) 2022 - 2024 grunfink et al. / MIT license */
3
4#include "xs.h"
5#include "xs_io.h"
6#include "xs_json.h"
7#include "xs_time.h"
8#include "xs_openssl.h"
9#include "xs_random.h"
10#include "xs_glob.h"
11#include "xs_curl.h"
12#include "xs_regex.h"
13
14#include "snac.h"
15
16#include <sys/stat.h>
17#include <stdlib.h>
18
19static const char *default_srv_config = "{"
20 "\"host\": \"\","
21 "\"prefix\": \"\","
22 "\"address\": \"127.0.0.1\","
23 "\"port\": 8001,"
24 "\"layout\": 0.0,"
25 "\"dbglevel\": 0,"
26 "\"queue_retry_minutes\": 2,"
27 "\"queue_retry_max\": 10,"
28 "\"queue_timeout\": 6,"
29 "\"queue_timeout_2\": 8,"
30 "\"cssurls\": [\"\"],"
31 "\"max_timeline_entries\": 50,"
32 "\"timeline_purge_days\": 120,"
33 "\"local_purge_days\": 0,"
34 "\"min_account_age\": 0,"
35 "\"admin_email\": \"\","
36 "\"admin_account\": \"\","
37 "\"title\": \"\","
38 "\"short_description\": \"\","
39 "\"protocol\": \"https\","
40 "\"fastcgi\": false"
41 "}";
42
43static const char *default_css =
44 "body { max-width: 48em; margin: auto; line-height: 1.5; padding: 0.8em; word-wrap: break-word; }\n"
45 "pre { overflow-x: scroll; }\n"
46 ".snac-embedded-video, img { max-width: 100% }\n"
47 ".snac-origin { font-size: 85% }\n"
48 ".snac-score { float: right; font-size: 85% }\n"
49 ".snac-top-user { text-align: center; padding-bottom: 2em }\n"
50 ".snac-top-user-name { font-size: 200% }\n"
51 ".snac-top-user-id { font-size: 150% }\n"
52 ".snac-announcement { border: black 1px solid; padding: 0.5em }\n"
53 ".snac-avatar { float: left; height: 2.5em; width: 2.5em; padding: 0.25em }\n"
54 ".snac-author { font-size: 90%; text-decoration: none }\n"
55 ".snac-author-tag { font-size: 80% }\n"
56 ".snac-pubdate { color: #a0a0a0; font-size: 90% }\n"
57 ".snac-top-controls { padding-bottom: 1.5em }\n"
58 ".snac-post { border-top: 1px solid #a0a0a0; }\n"
59 ".snac-children { padding-left: 1em; border-left: 1px solid #a0a0a0; }\n"
60 ".snac-textarea { font-family: inherit; width: 100% }\n"
61 ".snac-history { border: 1px solid #606060; border-radius: 3px; margin: 2.5em 0; padding: 0 2em }\n"
62 ".snac-btn-mute { float: right; margin-left: 0.5em }\n"
63 ".snac-btn-unmute { float: right; margin-left: 0.5em }\n"
64 ".snac-btn-follow { float: right; margin-left: 0.5em }\n"
65 ".snac-btn-unfollow { float: right; margin-left: 0.5em }\n"
66 ".snac-btn-hide { float: right; margin-left: 0.5em }\n"
67 ".snac-btn-delete { float: right; margin-left: 0.5em }\n"
68 ".snac-btn-limit { float: right; margin-left: 0.5em }\n"
69 ".snac-btn-unlimit { float: right; margin-left: 0.5em }\n"
70 ".snac-footer { margin-top: 2em; font-size: 75% }\n"
71 ".snac-poll-result { margin-left: auto; margin-right: auto; }\n"
72 "@media (prefers-color-scheme: dark) { \n"
73 " body, input, textarea { background-color: #000; color: #fff; }\n"
74 " a { color: #7799dd }\n"
75 " a:visited { color: #aa99dd }\n"
76 "}\n"
77;
78
79const char *snac_blurb =
80 "<p><b>%host%</b> is a <a href=\"https:/"
81 "/en.wikipedia.org/wiki/Fediverse\">Fediverse</a> "
82 "instance that uses the <a href=\"https:/"
83 "/en.wikipedia.org/wiki/ActivityPub\">ActivityPub</a> "
84 "protocol. In other words, users at this host can communicate with people "
85 "that use software like Mastodon, Pleroma, Friendica, etc. "
86 "all around the world.</p>\n"
87 "<p>This server runs the "
88 "<a href=\"" WHAT_IS_SNAC_URL "\">snac</a> software and there is no "
89 "automatic sign-up process.</p>\n"
90;
91
92static const char *greeting_html =
93 "<!DOCTYPE html>\n"
94 "<html><head>\n"
95 "<meta name=\"viewport\" content=\"width=device-width, initial-scale=1\"/>\n"
96 "<link rel=\"icon\" type=\"image/x-icon\" href=\"https://%host%/favicon.ico\"/>\n"
97 "<title>Welcome to %host%</title>\n"
98 "<body style=\"margin: auto; max-width: 50em\">\n"
99 "%blurb%"
100 "<p>The following users are part of this community:</p>\n"
101 "\n"
102 "%userlist%\n"
103 "\n"
104 "<p>This site is powered by <abbr title=\"Social Networks Are Crap\">snac</abbr>.</p>\n"
105 "</body></html>\n";
106
107int snac_init(const char *basedir)
108{
109 FILE *f;
110
111 if (basedir == NULL) {
112 printf("Base directory: "); fflush(stdout);
113 srv_basedir = xs_strip_i(xs_readline(stdin));
114 }
115 else
116 srv_basedir = xs_str_new(basedir);
117
118 if (srv_basedir == NULL || *srv_basedir == '\0')
119 return 1;
120
121 if (xs_endswith(srv_basedir, "/"))
122 srv_basedir = xs_crop_i(srv_basedir, 0, -1);
123
124 if (mtime(srv_basedir) != 0.0) {
125 printf("ERROR: directory '%s' must not exist.\n", srv_basedir);
126 return 1;
127 }
128
129 srv_config = xs_json_loads(default_srv_config);
130
131 xs *layout = xs_number_new(disk_layout);
132 srv_config = xs_dict_set(srv_config, "layout", layout);
133
134 printf("Network address [%s]: ", xs_dict_get(srv_config, "address")); fflush(stdout);
135 {
136 xs *i = xs_strip_i(xs_readline(stdin));
137 if (*i)
138 srv_config = xs_dict_set(srv_config, "address", i);
139 }
140
141 printf("Network port [%d]: ", (int)xs_number_get(xs_dict_get(srv_config, "port"))); fflush(stdout);
142 {
143 xs *i = xs_strip_i(xs_readline(stdin));
144 if (*i) {
145 xs *n = xs_number_new(atoi(i));
146 srv_config = xs_dict_set(srv_config, "port", n);
147 }
148 }
149
150 printf("Host name: "); fflush(stdout);
151 {
152 xs *i = xs_strip_i(xs_readline(stdin));
153 if (*i == '\0')
154 return 1;
155
156 srv_config = xs_dict_set(srv_config, "host", i);
157 }
158
159 printf("URL prefix: "); fflush(stdout);
160 {
161 xs *i = xs_strip_i(xs_readline(stdin));
162
163 if (*i) {
164 if (xs_endswith(i, "/"))
165 i = xs_crop_i(i, 0, -1);
166
167 srv_config = xs_dict_set(srv_config, "prefix", i);
168 }
169 }
170
171 printf("Admin email address (optional): "); fflush(stdout);
172 {
173 xs *i = xs_strip_i(xs_readline(stdin));
174
175 srv_config = xs_dict_set(srv_config, "admin_email", i);
176 }
177
178 if (mkdirx(srv_basedir) == -1) {
179 printf("ERROR: cannot create directory '%s'\n", srv_basedir);
180 return 1;
181 }
182
183 xs *udir = xs_fmt("%s/user", srv_basedir);
184 mkdirx(udir);
185
186 xs *odir = xs_fmt("%s/object", srv_basedir);
187 mkdirx(odir);
188
189 xs *qdir = xs_fmt("%s/queue", srv_basedir);
190 mkdirx(qdir);
191
192 xs *ibdir = xs_fmt("%s/inbox", srv_basedir);
193 mkdirx(ibdir);
194
195 xs *gfn = xs_fmt("%s/greeting.html", srv_basedir);
196 if ((f = fopen(gfn, "w")) == NULL) {
197 printf("ERROR: cannot create '%s'\n", gfn);
198 return 1;
199 }
200
201 xs *gh = xs_replace(greeting_html, "%blurb%", snac_blurb);
202 fwrite(gh, strlen(gh), 1, f);
203 fclose(f);
204
205 xs *sfn = xs_fmt("%s/style.css", srv_basedir);
206 if ((f = fopen(sfn, "w")) == NULL) {
207 printf("ERROR: cannot create '%s'\n", sfn);
208 return 1;
209 }
210
211 fwrite(default_css, strlen(default_css), 1, f);
212 fclose(f);
213
214 xs *cfn = xs_fmt("%s/server.json", srv_basedir);
215 if ((f = fopen(cfn, "w")) == NULL) {
216 printf("ERROR: cannot create '%s'\n", cfn);
217 return 1;
218 }
219
220 xs_json_dump(srv_config, 4, f);
221 fclose(f);
222
223 printf("Done.\n");
224 return 0;
225}
226
227
228void new_password(const char *uid, xs_str **clear_pwd, xs_str **hashed_pwd)
229/* creates a random password */
230{
231 int rndbuf[3];
232
233 xs_rnd_buf(rndbuf, sizeof(rndbuf));
234
235 *clear_pwd = xs_base64_enc((char *)rndbuf, sizeof(rndbuf));
236 *hashed_pwd = hash_password(uid, *clear_pwd, NULL);
237}
238
239
240int adduser(const char *uid)
241/* creates a new user */
242{
243 snac snac;
244 xs *config = xs_dict_new();
245 xs *date = xs_str_utctime(0, ISO_DATE_SPEC);
246 xs *pwd = NULL;
247 xs *pwd_f = NULL;
248 xs *key = NULL;
249 FILE *f;
250
251 if (uid == NULL) {
252 printf("Username: "); fflush(stdout);
253 uid = xs_strip_i(xs_readline(stdin));
254 }
255
256 if (!validate_uid(uid)) {
257 printf("ERROR: only alphanumeric characters and _ are allowed in user ids.\n");
258 return 1;
259 }
260
261 if (user_open(&snac, uid)) {
262 printf("ERROR: user '%s' already exists\n", snac.uid);
263 return 1;
264 }
265
266 new_password(uid, &pwd, &pwd_f);
267
268 config = xs_dict_append(config, "uid", uid);
269 config = xs_dict_append(config, "name", uid);
270 config = xs_dict_append(config, "avatar", "");
271 config = xs_dict_append(config, "bio", "");
272 config = xs_dict_append(config, "cw", "");
273 config = xs_dict_append(config, "published", date);
274 config = xs_dict_append(config, "passwd", pwd_f);
275
276 xs *basedir = xs_fmt("%s/user/%s", srv_basedir, uid);
277
278 if (mkdirx(basedir) == -1) {
279 printf("ERROR: cannot create directory '%s'\n", basedir);
280 return 0;
281 }
282
283 const char *dirs[] = {
284 "followers", "following", "muted", "hidden",
285 "public", "private", "queue", "history",
286 "static", NULL };
287 int n;
288
289 for (n = 0; dirs[n]; n++) {
290 xs *d = xs_fmt("%s/%s", basedir, dirs[n]);
291 mkdirx(d);
292 }
293
294 xs *cfn = xs_fmt("%s/user.json", basedir);
295
296 if ((f = fopen(cfn, "w")) == NULL) {
297 printf("ERROR: cannot create '%s'\n", cfn);
298 return 1;
299 }
300 else {
301 xs_json_dump(config, 4, f);
302 fclose(f);
303 }
304
305 printf("\nCreating RSA key...\n");
306 key = xs_evp_genkey(4096);
307 printf("Done.\n");
308
309 xs *kfn = xs_fmt("%s/key.json", basedir);
310
311 if ((f = fopen(kfn, "w")) == NULL) {
312 printf("ERROR: cannot create '%s'\n", kfn);
313 return 1;
314 }
315 else {
316 xs_json_dump(key, 4, f);
317 fclose(f);
318 }
319
320 printf("\nUser password is %s\n", pwd);
321
322 printf("\nGo to %s/%s and continue configuring your user there.\n", srv_baseurl, uid);
323
324 return 0;
325}
326
327
328int resetpwd(snac *snac)
329/* creates a new password for the user */
330{
331 xs *clear_pwd = NULL;
332 xs *hashed_pwd = NULL;
333 xs *fn = xs_fmt("%s/user.json", snac->basedir);
334 FILE *f;
335 int ret = 0;
336
337 new_password(snac->uid, &clear_pwd, &hashed_pwd);
338
339 snac->config = xs_dict_set(snac->config, "passwd", hashed_pwd);
340
341 if ((f = fopen(fn, "w")) != NULL) {
342 xs_json_dump(snac->config, 4, f);
343 fclose(f);
344
345 printf("New password for user %s is %s\n", snac->uid, clear_pwd);
346 }
347 else {
348 printf("ERROR: cannot write to %s\n", fn);
349 ret = 1;
350 }
351
352 return ret;
353}
354
355
356void rm_rf(const char *dir)
357/* does an rm -rf (yes, I'm also scared) */
358{
359 xs *d = xs_str_cat(xs_dup(dir), "/" "*");
360 xs *l = xs_glob(d, 0, 0);
361 xs_list *p = l;
362 const xs_str *v;
363
364 if (dbglevel >= 1)
365 printf("Deleting directory %s\n", dir);
366
367 while (xs_list_iter(&p, &v)) {
368 struct stat st;
369
370 if (stat(v, &st) != -1) {
371 if (st.st_mode & S_IFDIR) {
372 rm_rf(v);
373 }
374 else {
375 if (dbglevel >= 1)
376 printf("Deleting file %s\n", v);
377
378 if (unlink(v) == -1)
379 printf("ERROR: cannot delete file %s\n", v);
380 }
381 }
382 else
383 printf("ERROR: stat() fail for %s\n", v);
384 }
385
386 if (rmdir(dir) == -1)
387 printf("ERROR: cannot delete directory %s\n", dir);
388}
389
390
391int deluser(snac *user)
392/* deletes a user */
393{
394 int ret = 0;
395 xs *fwers = following_list(user);
396 xs_list *p = fwers;
397 const xs_str *v;
398
399 while (xs_list_iter(&p, &v)) {
400 xs *object = NULL;
401
402 if (valid_status(following_get(user, v, &object))) {
403 xs *msg = msg_undo(user, xs_dict_get(object, "object"));
404
405 following_del(user, v);
406
407 enqueue_output_by_actor(user, msg, v, 0);
408
409 printf("Unfollowing actor %s\n", v);
410 }
411 }
412
413 rm_rf(user->basedir);
414
415 return ret;
416}
417
418
419void verify_links(snac *user)
420/* verifies a user's links */
421{
422 const xs_dict *p = xs_dict_get(user->config, "metadata");
423 const char *k, *v;
424 int changed = 0;
425
426 xs *headers = xs_dict_new();
427 headers = xs_dict_append(headers, "accept", "text/html");
428 headers = xs_dict_append(headers, "user-agent", USER_AGENT " (link verify)");
429
430 int c = 0;
431 while (p && xs_dict_next(p, &k, &v, &c)) {
432 /* not an https link? skip */
433 if (!xs_startswith(v, "https:/" "/"))
434 continue;
435
436 int status;
437 xs *req = NULL;
438 xs *payload = NULL;
439 int p_size = 0;
440
441 req = xs_http_request("GET", v, headers, NULL, 0, &status,
442 &payload, &p_size, 0);
443
444 if (!valid_status(status)) {
445 snac_log(user, xs_fmt("link %s verify error %d", v, status));
446 continue;
447 }
448
449 /* extract the links */
450 xs *ls = xs_regex_select(payload, "< *(a|link) +[^>]+>");
451
452 xs_list *lp = ls;
453 const char *ll;
454 int vfied = 0;
455
456 while (!vfied && xs_list_iter(&lp, &ll)) {
457 /* extract href and rel */
458 xs *r = xs_regex_select(ll, "(href|rel) *= *(\"[^\"]*\"|'[^']*')");
459
460 /* must have both attributes */
461 if (xs_list_len(r) != 2)
462 continue;
463
464 xs *href = NULL;
465 int is_rel_me = 0;
466 xs_list *pr = r;
467 const char *ar;
468
469 while (xs_list_iter(&pr, &ar)) {
470 xs *nq = xs_dup(ar);
471
472 nq = xs_replace_i(nq, "\"", "");
473 nq = xs_replace_i(nq, "'", "");
474
475 xs *r2 = xs_split_n(nq, "=", 1);
476 if (xs_list_len(r2) != 2)
477 continue;
478
479 xs *ak = xs_strip_i(xs_dup(xs_list_get(r2, 0)));
480 xs *av = xs_strip_i(xs_dup(xs_list_get(r2, 1)));
481
482 if (strcmp(ak, "href") == 0)
483 href = xs_dup(av);
484 else
485 if (strcmp(ak, "rel") == 0) {
486 /* split the value by spaces */
487 xs *vbs = xs_split(av, " ");
488
489 /* is any of it "me"? */
490 if (xs_list_in(vbs, "me") != -1)
491 is_rel_me = 1;
492 }
493 }
494
495 /* after all this acrobatics, do we have an href and a rel="me"? */
496 if (href != NULL && is_rel_me) {
497 /* is it the same as the actor? */
498 if (strcmp(href, user->actor) == 0) {
499 /* got it! */
500 xs *verified_time = xs_number_new((double)time(NULL));
501
502 if (user->links == NULL)
503 user->links = xs_dict_new();
504
505 user->links = xs_dict_set(user->links, v, verified_time);
506
507 vfied = 1;
508 }
509 else
510 snac_debug(user, 1,
511 xs_fmt("verify link %s rel='me' found but not related (%s)", v, href));
512 }
513 }
514
515 if (vfied) {
516 changed++;
517 snac_log(user, xs_fmt("link %s verified", v));
518 }
519 else {
520 snac_log(user, xs_fmt("link %s not verified (rel='me' not found)", v));
521 }
522 }
523
524 if (changed) {
525 FILE *f;
526
527 /* update the links.json file */
528 xs *fn = xs_fmt("%s/links.json", user->basedir);
529 xs *bfn = xs_fmt("%s.bak", fn);
530
531 rename(fn, bfn);
532
533 if ((f = fopen(fn, "w")) != NULL) {
534 xs_json_dump(user->links, 4, f);
535 fclose(f);
536 }
537 else
538 rename(bfn, fn);
539 }
540}
