2 * Copyright (C) 2018 Daniel Golle <daniel@makrotopia.org>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 3
6 * as published by the Free Software Foundation
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
29 #include <json-c/json.h>
30 #include <libubox/blob.h>
31 #include <libubox/utils.h>
32 #include <libubox/list.h>
33 #include <libubox/vlist.h>
34 #include <libubox/blobmsg_json.h>
38 #define CERT_BUF_LEN 4096
50 #ifndef UCERT_STRIP_MESSAGES
51 #define DPRINTF(format, ...) \
54 fprintf(stderr, "%s(%d): " format, __func__, __LINE__, ## __VA_ARGS__); \
57 #define DPRINTF(format, ...) do { } while (0)
63 * | SIGNATURE | PAYLOAD |
64 * | |[ BLOBMSG CONTAINER ]|
65 * | |[[T,i,v,e,f,pubkey ]]|
73 static const struct blob_attr_info cert_policy[CERT_ATTR_MAX] = {
74 [CERT_ATTR_SIGNATURE] = { .type = BLOB_ATTR_BINARY },
75 [CERT_ATTR_PAYLOAD] = { .type = BLOB_ATTR_NESTED },
83 static const struct blobmsg_policy cert_cont_policy[CERT_CT_ATTR_MAX] = {
84 [CERT_CT_ATTR_PAYLOAD] = { .name = "ucert", .type = BLOBMSG_TYPE_TABLE },
87 enum cert_payload_attr {
88 CERT_PL_ATTR_CERTTYPE,
90 CERT_PL_ATTR_VALIDFROMTIME,
91 CERT_PL_ATTR_EXPIRETIME,
93 CERT_PL_ATTR_KEY_FINGERPRINT,
103 static const struct blobmsg_policy cert_payload_policy[CERT_PL_ATTR_MAX] = {
104 [CERT_PL_ATTR_CERTTYPE] = { .name = "certtype", .type = BLOBMSG_TYPE_INT32 },
105 [CERT_PL_ATTR_CERTID] = { .name = "certid", .type = BLOBMSG_TYPE_INT32 },
106 [CERT_PL_ATTR_VALIDFROMTIME] = { .name = "validfrom", .type = BLOBMSG_TYPE_INT64 },
107 [CERT_PL_ATTR_EXPIRETIME] = { .name = "expiresat", .type = BLOBMSG_TYPE_INT64 },
108 [CERT_PL_ATTR_PUBKEY] = { .name = "pubkey", .type = BLOBMSG_TYPE_STRING },
109 [CERT_PL_ATTR_KEY_FINGERPRINT] = { .name = "fingerprint", .type = BLOBMSG_TYPE_STRING },
112 /* list to store certificate chain at runtime */
114 struct list_head list;
115 struct blob_attr *cert[CERT_ATTR_MAX];
118 /* write buffer to file */
119 static bool write_file(const char *filename, void *buf, size_t len, bool append) {
123 f = fopen(filename, append?"a":"w");
127 outlen = fwrite(buf, 1, len, f);
129 return (outlen == len);
132 /* load certfile into list */
133 static int cert_load(const char *certfile, struct list_head *chain) {
135 struct blob_attr *certtb[CERT_ATTR_MAX];
136 struct blob_attr *bufpt;
137 struct cert_object *cobj;
138 char filebuf[CERT_BUF_LEN];
139 int ret = 0, pret = 0;
142 f = fopen(certfile, "r");
146 len = fread(&filebuf, 1, CERT_BUF_LEN - 1, f);
150 ret = ferror(f) || !feof(f);
155 bufpt = (struct blob_attr *)filebuf;
157 pret = blob_parse_untrusted(bufpt, len, certtb, cert_policy, CERT_ATTR_MAX);
159 /* no attributes found */
162 if (pos + blob_pad_len(bufpt) > len)
163 /* blob exceeds filebuffer */
166 pos += blob_pad_len(bufpt);
168 if (!certtb[CERT_ATTR_SIGNATURE])
169 /* no signature -> drop */
172 cobj = calloc(1, sizeof(*cobj));
173 cobj->cert[CERT_ATTR_SIGNATURE] = blob_memdup(certtb[CERT_ATTR_SIGNATURE]);
174 if (certtb[CERT_ATTR_PAYLOAD])
175 cobj->cert[CERT_ATTR_PAYLOAD] = blob_memdup(certtb[CERT_ATTR_PAYLOAD]);
177 list_add_tail(&cobj->list, chain);
179 /* repeat parsing while there is still enough remaining data in buffer */
180 } while(len > pos + sizeof(struct blob_attr) && (bufpt = blob_next(bufpt)));
186 /* append signature to certfile */
187 static int cert_append(const char *certfile, const char *sigfile) {
189 char filebuf[CERT_BUF_LEN];
190 struct blob_buf sigbuf = {0};
194 fs = fopen(sigfile, "r");
198 len = fread(&filebuf, 1, CERT_BUF_LEN - 1, fs);
199 ret = ferror(fs) || !feof(fs) || (len < 64);
204 blob_buf_init(&sigbuf, 0);
205 blob_put(&sigbuf, CERT_ATTR_SIGNATURE, filebuf, len);
206 ret = write_file(certfile, sigbuf.head, blob_raw_len(sigbuf.head), true);
207 blob_buf_free(&sigbuf);
212 /* verify the signature of a single chain element */
213 static int cert_verify_blob(struct blob_attr *cert[CERT_ATTR_MAX],
214 const char *pubkeyfile, const char *pubkeydir) {
216 char msgfname[256], sigfname[256];
218 char tmpdir[] = "/tmp/ucert-XXXXXX";
220 if (mkdtemp(tmpdir) == NULL)
223 snprintf(msgfname, sizeof(msgfname) - 1, "%s/%s", tmpdir, "payload");
224 snprintf(sigfname, sizeof(sigfname) - 1, "%s/%s", tmpdir, "payload.sig");
226 for (i = 0; i < CERT_ATTR_MAX; i++) {
227 struct blob_attr *v = cert[i];
232 switch(cert_policy[i].type) {
233 case BLOB_ATTR_BINARY:
234 write_file(sigfname, blob_data(v), blob_len(v), false);
236 case BLOB_ATTR_NESTED:
237 write_file(msgfname, blob_data(v), blob_len(v), false);
242 ret = usign_v(msgfname, pubkeyfile, pubkeydir, sigfname, quiet);
251 /* verify cert chain (and message) */
252 static int chain_verify(const char *msgfile, const char *pubkeyfile,
253 const char *pubkeydir, struct list_head *chain) {
254 struct cert_object *cobj;
255 struct blob_attr *containertb[CERT_CT_ATTR_MAX];
256 struct blob_attr *payloadtb[CERT_PL_ATTR_MAX];
257 char tmpdir[] = "/tmp/ucert-XXXXXX";
258 char chainedpubkey[256] = {0};
259 char chainedfp[17] = {0};
260 char extsigfile[256] = {0};
265 if (mkdtemp(tmpdir) == NULL)
271 gettimeofday(&tv, NULL);
273 list_for_each_entry(cobj, chain, list) {
274 /* blob has payload, verify that using signature */
275 if (cobj->cert[CERT_ATTR_PAYLOAD]) {
280 ret = cert_verify_blob(cobj->cert, chainedpubkey[0]?chainedpubkey:pubkeyfile, pubkeydir);
282 goto clean_and_return;
284 blobmsg_parse(cert_cont_policy,
285 ARRAY_SIZE(cert_cont_policy),
287 blob_data(cobj->cert[CERT_ATTR_PAYLOAD]),
288 blob_len(cobj->cert[CERT_ATTR_PAYLOAD]));
289 if (!containertb[CERT_CT_ATTR_PAYLOAD]) {
291 DPRINTF("no ucert in signed payload\n");
292 goto clean_and_return;
294 blobmsg_parse(cert_payload_policy,
295 ARRAY_SIZE(cert_payload_policy),
297 blobmsg_data(containertb[CERT_CT_ATTR_PAYLOAD]),
298 blobmsg_data_len(containertb[CERT_CT_ATTR_PAYLOAD]));
300 if (!payloadtb[CERT_PL_ATTR_CERTTYPE] ||
301 !payloadtb[CERT_PL_ATTR_VALIDFROMTIME] ||
302 !payloadtb[CERT_PL_ATTR_EXPIRETIME] ||
303 !payloadtb[CERT_PL_ATTR_PUBKEY]) {
305 DPRINTF("missing mandatory ucert attributes\n");
306 goto clean_and_return;
308 certtype = blobmsg_get_u32(payloadtb[CERT_PL_ATTR_CERTTYPE]);
309 validfrom = blobmsg_get_u64(payloadtb[CERT_PL_ATTR_VALIDFROMTIME]);
310 expiresat = blobmsg_get_u64(payloadtb[CERT_PL_ATTR_EXPIRETIME]);
312 if (certtype != CERTTYPE_AUTH) {
314 DPRINTF("wrong certificate type\n");
315 goto clean_and_return;
318 if (tv.tv_sec < validfrom ||
319 tv.tv_sec >= expiresat) {
321 DPRINTF("certificate expired\n");
322 goto clean_and_return;
325 snprintf(chainedpubkey, sizeof(chainedpubkey) - 1, "%s/%s", tmpdir, "chained-pubkey");
326 write_file(chainedpubkey,
327 blobmsg_data(payloadtb[CERT_PL_ATTR_PUBKEY]),
328 blobmsg_data_len(payloadtb[CERT_PL_ATTR_PUBKEY]),
331 if (usign_f_pubkey(chainedfp, chainedpubkey)) {
332 DPRINTF("cannot get fingerprint for chained key\n");
334 goto clean_and_return;
336 if (pubkeydir && _usign_key_is_revoked(chainedfp, pubkeydir)) {
337 DPRINTF("key %s has been revoked!\n", chainedfp);
339 goto clean_and_return;
342 /* blob doesn't have payload, verify message using signature */
344 snprintf(extsigfile, sizeof(extsigfile) - 1, "%s/%s", tmpdir, "ext-sig");
345 write_file(extsigfile,
346 blob_data(cobj->cert[CERT_ATTR_SIGNATURE]),
347 blob_len(cobj->cert[CERT_ATTR_SIGNATURE]),
349 checkmsg = ret = usign_v(msgfile,
350 chainedpubkey[0]?chainedpubkey:pubkeyfile,
351 pubkeydir, extsigfile, quiet);
354 DPRINTF("stray trailing signature without anything to verify!\n");
361 DPRINTF("missing signature to verify message!\n");
364 if (chainedpubkey[0])
365 unlink(chainedpubkey);
367 return ret | checkmsg;
371 /* dump single chain element to console */
372 static void cert_dump_blob(struct blob_attr *cert[CERT_ATTR_MAX]) {
376 for (i = 0; i < CERT_ATTR_MAX; i++) {
377 struct blob_attr *v = cert[i];
382 switch(cert_policy[i].type) {
383 case BLOB_ATTR_BINARY:
384 printf("signature:\n---\n%s---\n", (char *) blob_data(v));
386 case BLOB_ATTR_NESTED:
387 json = blobmsg_format_json_indent(blob_data(v), false, 0);
389 DPRINTF("cannot parse payload\n");
392 printf("payload:\n---\n%s\n---\n", json);
399 /* dump certfile to console */
400 static int cert_dump(const char *certfile) {
401 struct cert_object *cobj;
402 static LIST_HEAD(certchain);
403 unsigned int count = 0;
405 if (cert_load(certfile, &certchain)) {
406 DPRINTF("cannot parse cert\n");
410 list_for_each_entry(cobj, &certchain, list) {
411 printf("=== CHAIN ELEMENT %02u ===\n", ++count);
412 cert_dump_blob(cobj->cert);
418 /* issue an auth certificate for pubkey */
419 static int cert_issue(const char *certfile, const char *pubkeyfile, const char *seckeyfile) {
420 struct blob_buf payloadbuf = {0};
421 struct blob_buf certbuf = {0};
429 char fname[256], sfname[256];
431 char tmpdir[] = "/tmp/ucert-XXXXXX";
433 pkf = fopen(pubkeyfile, "r");
437 pklen = fread(pkb, 1, 512, pkf);
445 if (usign_f_pubkey(pkfp, pubkeyfile))
448 gettimeofday(&tv, NULL);
450 if (mkdtemp(tmpdir) == NULL)
453 while (revoker >= 0) {
454 blob_buf_init(&payloadbuf, 0);
455 c = blobmsg_open_table(&payloadbuf, "ucert");
456 blobmsg_add_u32(&payloadbuf, "certtype", revoker?CERTTYPE_REVOKE:CERTTYPE_AUTH);
457 blobmsg_add_u64(&payloadbuf, "validfrom", tv.tv_sec);
459 blobmsg_add_u64(&payloadbuf, "expiresat", tv.tv_sec + 60 * 60 * 24 * 365);
460 blobmsg_add_string(&payloadbuf, "pubkey", pkb);
462 blobmsg_add_string(&payloadbuf, "fingerprint", pkfp);
465 blobmsg_close_table(&payloadbuf, c);
467 snprintf(fname, sizeof(fname) - 1, "%s/%s", tmpdir, revoker?"revoker":"payload");
468 write_file(fname, blob_data(payloadbuf.head), blob_len(payloadbuf.head), false);
470 snprintf(sfname, sizeof(sfname) - 1, "%s/%s", tmpdir, revoker?"revoker.sig":"payload.sig");
471 if (usign_s(fname, seckeyfile, sfname, quiet))
474 sigf = fopen(sfname, "r");
478 siglen = fread(sigb, 1, 1024, sigf);
488 blob_buf_init(&certbuf, 0);
489 blob_put(&certbuf, CERT_ATTR_SIGNATURE, sigb, siglen);
490 blob_put(&certbuf, CERT_ATTR_PAYLOAD, blob_data(payloadbuf.head), blob_len(payloadbuf.head));
491 snprintf(fname, sizeof(fname) - 1, "%s%s", certfile, revoker?".revoke":"");
492 write_file(fname, certbuf.head, blob_raw_len(certbuf.head), true);
493 blob_buf_free(&certbuf);
494 blob_buf_free(&payloadbuf);
505 /* process revoker certificate */
506 static int cert_process_revoker(const char *certfile, const char *pubkeydir) {
507 static LIST_HEAD(certchain);
508 struct cert_object *cobj;
509 struct blob_attr *containertb[CERT_CT_ATTR_MAX];
510 struct blob_attr *payloadtb[CERT_PL_ATTR_MAX];
514 enum certtype_id certtype;
520 if (cert_load(certfile, &certchain)) {
521 DPRINTF("cannot parse cert\n");
525 gettimeofday(&tv, NULL);
527 list_for_each_entry(cobj, &certchain, list) {
528 if (!cobj->cert[CERT_ATTR_PAYLOAD])
531 /* blob has payload, verify that using signature */
532 ret = cert_verify_blob(cobj->cert, NULL, pubkeydir);
536 blobmsg_parse(cert_cont_policy,
537 ARRAY_SIZE(cert_cont_policy),
539 blob_data(cobj->cert[CERT_ATTR_PAYLOAD]),
540 blob_len(cobj->cert[CERT_ATTR_PAYLOAD]));
541 if (!containertb[CERT_CT_ATTR_PAYLOAD]) {
542 DPRINTF("no ucert in signed payload\n");
546 blobmsg_parse(cert_payload_policy,
547 ARRAY_SIZE(cert_payload_policy),
549 blobmsg_data(containertb[CERT_CT_ATTR_PAYLOAD]),
550 blobmsg_data_len(containertb[CERT_CT_ATTR_PAYLOAD]));
552 if (!payloadtb[CERT_PL_ATTR_CERTTYPE] ||
553 !payloadtb[CERT_PL_ATTR_VALIDFROMTIME] ||
554 !payloadtb[CERT_PL_ATTR_KEY_FINGERPRINT]) {
555 DPRINTF("missing mandatory ucert attributes\n");
559 certtype = blobmsg_get_u32(payloadtb[CERT_PL_ATTR_CERTTYPE]);
560 validfrom = blobmsg_get_u64(payloadtb[CERT_PL_ATTR_VALIDFROMTIME]);
561 fingerprint = blobmsg_get_string(payloadtb[CERT_PL_ATTR_KEY_FINGERPRINT]);
563 if (certtype != CERTTYPE_REVOKE) {
564 DPRINTF("wrong certificate type\n");
568 if (tv.tv_sec < validfrom) {
572 snprintf(rfname, sizeof(rfname)-1, "%s/%s", pubkeydir, fingerprint);
573 /* check if entry in pubkeydir exists */
574 if (stat(rfname, &st) == 0) {
575 if (_usign_key_is_revoked(fingerprint, pubkeydir)) {
576 DPRINTF("existing revoker deadlink for key %s\n", fingerprint);
580 /* remove any other entry */
585 ret = symlink(".revoked.", rfname);
589 DPRINTF("created revoker deadlink for key %s\n", fingerprint);
595 /* load and verify certfile (and message) */
596 static int cert_verify(const char *certfile, const char *pubkeyfile, const char *pubkeydir, const char *msgfile) {
597 static LIST_HEAD(certchain);
599 if (cert_load(certfile, &certchain)) {
600 DPRINTF("cannot parse cert\n");
604 return chain_verify(msgfile, pubkeyfile, pubkeydir, &certchain);
608 static int usage(const char *cmd)
610 #ifndef UCERT_STRIP_MESSAGES
612 "Usage: %s <command> <options>\n"
615 " -A: append signature (needs -c and -x)\n"
616 " -D: dump (needs -c)\n"
617 " -I: issue cert and revoker (needs -c and -p and -s)\n"
618 #endif /* UCERT_FULL */
619 " -R: process revoker certificate (needs -c and -P)\n"
620 " -V: verify (needs -c and -p|-P, may have -m)\n"
622 " -c <file>: certificate file\n"
623 " -m <file>: message file (verify only)\n"
624 " -p <file>: public key file\n"
625 " -P <path>: public key directory (verify only)\n"
626 " -q: quiet (do not print verification result, use return code only)\n"
628 " -s <file>: secret key file (issue only)\n"
629 " -x <file>: signature file (append only)\n"
630 #endif /* UCERT_FULL */
633 #endif /* UCERT_STRIP_MESSAGES */
637 /* parse command line options and call functions */
638 int main(int argc, char *argv[]) {
640 const char *msgfile = NULL;
641 const char *pubkeyfile = NULL;
642 const char *pubkeydir = NULL;
643 const char *certfile = NULL;
645 const char *sigfile = NULL;
646 const char *seckeyfile = NULL;
650 while ((ch = getopt(argc, argv,
660 return usage(argv[0]);
665 return usage(argv[0]);
670 return usage(argv[0]);
676 return usage(argv[0]);
681 return usage(argv[0]);
685 if (certfile || cmd == CMD_NONE)
686 return usage(argv[0]);
690 if (msgfile || cmd != CMD_VERIFY)
691 return usage(argv[0]);
695 if (pubkeyfile || (cmd != CMD_VERIFY && cmd != CMD_ISSUE) || cmd == CMD_NONE)
696 return usage(argv[0]);
700 if (pubkeydir || (cmd != CMD_VERIFY && cmd != CMD_REVOKE) || cmd == CMD_NONE)
701 return usage(argv[0]);
706 return usage(argv[0]);
711 if (seckeyfile || cmd != CMD_ISSUE || cmd == CMD_NONE)
712 return usage(argv[0]);
716 if (sigfile || cmd != CMD_APPEND || cmd == CMD_NONE)
717 return usage(argv[0]);
722 return usage(argv[0]);
729 if (certfile && sigfile)
730 return cert_append(certfile, sigfile);
732 return usage(argv[0]);
735 return cert_dump(certfile);
737 return usage(argv[0]);
739 if (certfile && pubkeyfile && seckeyfile)
740 return cert_issue(certfile, pubkeyfile, seckeyfile);
742 return usage(argv[0]);
745 if (certfile && pubkeydir)
746 return cert_process_revoker(certfile, pubkeydir);
748 return usage(argv[0]);
750 if (certfile && (pubkeyfile || pubkeydir))
751 return cert_verify(certfile, pubkeyfile, pubkeydir, msgfile);
753 return usage(argv[0]);
755 return usage(argv[0]);
759 return usage(argv[0]);