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, ...) if (!quiet) fprintf(stderr, "%s(%d): " format, __func__, __LINE__, ## __VA_ARGS__)
53 #define DPRINTF(format, ...)
59 * | SIGNATURE | PAYLOAD |
60 * | |[ BLOBMSG CONTAINER ]|
61 * | |[[T,i,v,e,f,pubkey ]]|
69 static const struct blob_attr_info cert_policy[CERT_ATTR_MAX] = {
70 [CERT_ATTR_SIGNATURE] = { .type = BLOB_ATTR_BINARY },
71 [CERT_ATTR_PAYLOAD] = { .type = BLOB_ATTR_NESTED },
79 static const struct blobmsg_policy cert_cont_policy[CERT_CT_ATTR_MAX] = {
80 [CERT_CT_ATTR_PAYLOAD] = { .name = "ucert", .type = BLOBMSG_TYPE_TABLE },
83 enum cert_payload_attr {
84 CERT_PL_ATTR_CERTTYPE,
86 CERT_PL_ATTR_VALIDFROMTIME,
87 CERT_PL_ATTR_EXPIRETIME,
89 CERT_PL_ATTR_KEY_FINGERPRINT,
99 static const struct blobmsg_policy cert_payload_policy[CERT_PL_ATTR_MAX] = {
100 [CERT_PL_ATTR_CERTTYPE] = { .name = "certtype", .type = BLOBMSG_TYPE_INT32 },
101 [CERT_PL_ATTR_CERTID] = { .name = "certid", .type = BLOBMSG_TYPE_INT32 },
102 [CERT_PL_ATTR_VALIDFROMTIME] = { .name = "validfrom", .type = BLOBMSG_TYPE_INT64 },
103 [CERT_PL_ATTR_EXPIRETIME] = { .name = "expiresat", .type = BLOBMSG_TYPE_INT64 },
104 [CERT_PL_ATTR_PUBKEY] = { .name = "pubkey", .type = BLOBMSG_TYPE_STRING },
105 [CERT_PL_ATTR_KEY_FINGERPRINT] = { .name = "fingerprint", .type = BLOBMSG_TYPE_STRING },
108 /* list to store certificate chain at runtime */
110 struct list_head list;
111 struct blob_attr *cert[CERT_ATTR_MAX];
114 /* write buffer to file */
115 static int write_file(const char *filename, void *buf, size_t len, bool append) {
119 f = fopen(filename, append?"a":"w");
123 outlen = fwrite(buf, 1, len, f);
125 return (outlen == len);
128 /* load certfile into list */
129 static int cert_load(const char *certfile, struct list_head *chain) {
131 struct blob_attr *certtb[CERT_ATTR_MAX];
132 struct blob_attr *bufpt;
133 struct cert_object *cobj;
134 char filebuf[CERT_BUF_LEN];
135 int ret = 0, pret = 0;
138 f = fopen(certfile, "r");
142 len = fread(&filebuf, 1, CERT_BUF_LEN - 1, f);
146 ret = ferror(f) || !feof(f);
151 bufpt = (struct blob_attr *)filebuf;
153 pret = blob_parse(bufpt, certtb, cert_policy, CERT_ATTR_MAX);
155 /* no attributes found */
158 if (pos + blob_pad_len(bufpt) > len)
159 /* blob exceeds filebuffer */
162 pos += blob_pad_len(bufpt);
164 if (!certtb[CERT_ATTR_SIGNATURE])
165 /* no signature -> drop */
168 cobj = calloc(1, sizeof(*cobj));
169 cobj->cert[CERT_ATTR_SIGNATURE] = blob_memdup(certtb[CERT_ATTR_SIGNATURE]);
170 if (certtb[CERT_ATTR_PAYLOAD])
171 cobj->cert[CERT_ATTR_PAYLOAD] = blob_memdup(certtb[CERT_ATTR_PAYLOAD]);
173 list_add_tail(&cobj->list, chain);
175 bufpt = blob_next(bufpt);
176 /* repeat parsing while there is still enough remaining data in buffer */
177 } while(len > pos + sizeof(struct blob_attr));
183 /* append signature to certfile */
184 static int cert_append(const char *certfile, const char *sigfile) {
186 char filebuf[CERT_BUF_LEN];
187 struct blob_buf sigbuf;
191 fs = fopen(sigfile, "r");
195 len = fread(&filebuf, 1, CERT_BUF_LEN - 1, fs);
196 ret = ferror(fs) || !feof(fs) || (len < 64);
201 blob_buf_init(&sigbuf, 0);
202 blob_put(&sigbuf, CERT_ATTR_SIGNATURE, filebuf, len);
203 ret = write_file(certfile, sigbuf.head, blob_raw_len(sigbuf.head), true);
204 blob_buf_free(&sigbuf);
209 /* verify the signature of a single chain element */
210 static int cert_verify_blob(struct blob_attr *cert[CERT_ATTR_MAX],
211 const char *pubkeyfile, const char *pubkeydir) {
213 char msgfname[256], sigfname[256];
215 char tmpdir[] = "/tmp/ucert-XXXXXX";
217 if (mkdtemp(tmpdir) == NULL)
220 snprintf(msgfname, sizeof(msgfname) - 1, "%s/%s", tmpdir, "payload");
221 snprintf(sigfname, sizeof(sigfname) - 1, "%s/%s", tmpdir, "payload.sig");
223 for (i = 0; i < CERT_ATTR_MAX; i++) {
224 struct blob_attr *v = cert[i];
229 switch(cert_policy[i].type) {
230 case BLOB_ATTR_BINARY:
231 write_file(sigfname, blob_data(v), blob_len(v), false);
233 case BLOB_ATTR_NESTED:
234 write_file(msgfname, blob_data(v), blob_len(v), false);
239 ret = usign_v(msgfname, pubkeyfile, pubkeydir, sigfname, quiet);
248 /* verify cert chain (and message) */
249 static int chain_verify(const char *msgfile, const char *pubkeyfile,
250 const char *pubkeydir, struct list_head *chain) {
251 struct cert_object *cobj;
252 struct blob_attr *containertb[CERT_CT_ATTR_MAX];
253 struct blob_attr *payloadtb[CERT_PL_ATTR_MAX];
254 char tmpdir[] = "/tmp/ucert-XXXXXX";
255 char chainedpubkey[256] = {0};
256 char chainedfp[17] = {0};
257 char extsigfile[256] = {0};
262 if (mkdtemp(tmpdir) == NULL)
268 gettimeofday(&tv, NULL);
270 list_for_each_entry(cobj, chain, list) {
271 /* blob has payload, verify that using signature */
272 if (cobj->cert[CERT_ATTR_PAYLOAD]) {
277 ret = cert_verify_blob(cobj->cert, chainedpubkey[0]?chainedpubkey:pubkeyfile, pubkeydir);
279 goto clean_and_return;
281 blobmsg_parse(cert_cont_policy,
282 ARRAY_SIZE(cert_cont_policy),
284 blob_data(cobj->cert[CERT_ATTR_PAYLOAD]),
285 blob_len(cobj->cert[CERT_ATTR_PAYLOAD]));
286 if (!containertb[CERT_CT_ATTR_PAYLOAD]) {
288 DPRINTF("no ucert in signed payload\n");
289 goto clean_and_return;
291 blobmsg_parse(cert_payload_policy,
292 ARRAY_SIZE(cert_payload_policy),
294 blobmsg_data(containertb[CERT_CT_ATTR_PAYLOAD]),
295 blobmsg_data_len(containertb[CERT_CT_ATTR_PAYLOAD]));
297 if (!payloadtb[CERT_PL_ATTR_CERTTYPE] ||
298 !payloadtb[CERT_PL_ATTR_VALIDFROMTIME] ||
299 !payloadtb[CERT_PL_ATTR_EXPIRETIME] ||
300 !payloadtb[CERT_PL_ATTR_PUBKEY]) {
302 DPRINTF("missing mandatory ucert attributes\n");
303 goto clean_and_return;
305 certtype = blobmsg_get_u32(payloadtb[CERT_PL_ATTR_CERTTYPE]);
306 validfrom = blobmsg_get_u64(payloadtb[CERT_PL_ATTR_VALIDFROMTIME]);
307 expiresat = blobmsg_get_u64(payloadtb[CERT_PL_ATTR_EXPIRETIME]);
309 if (certtype != CERTTYPE_AUTH) {
311 DPRINTF("wrong certificate type\n");
312 goto clean_and_return;
315 if (tv.tv_sec < validfrom ||
316 tv.tv_sec >= expiresat) {
318 DPRINTF("certificate expired\n");
319 goto clean_and_return;
322 snprintf(chainedpubkey, sizeof(chainedpubkey) - 1, "%s/%s", tmpdir, "chained-pubkey");
323 write_file(chainedpubkey,
324 blobmsg_data(payloadtb[CERT_PL_ATTR_PUBKEY]),
325 blobmsg_data_len(payloadtb[CERT_PL_ATTR_PUBKEY]),
328 if (usign_f_pubkey(chainedfp, chainedpubkey)) {
329 DPRINTF("cannot get fingerprint for chained key\n");
331 goto clean_and_return;
333 if (pubkeydir && _usign_key_is_revoked(chainedfp, pubkeydir)) {
334 DPRINTF("key %s has been revoked!\n", chainedfp);
336 goto clean_and_return;
339 /* blob doesn't have payload, verify message using signature */
341 snprintf(extsigfile, sizeof(extsigfile) - 1, "%s/%s", tmpdir, "ext-sig");
342 write_file(extsigfile,
343 blob_data(cobj->cert[CERT_ATTR_SIGNATURE]),
344 blob_len(cobj->cert[CERT_ATTR_SIGNATURE]),
346 checkmsg = ret = usign_v(msgfile,
347 chainedpubkey[0]?chainedpubkey:pubkeyfile,
348 pubkeydir, extsigfile, quiet);
351 DPRINTF("stray trailing signature without anything to verify!\n");
358 DPRINTF("missing signature to verify message!\n");
361 if (chainedpubkey[0])
362 unlink(chainedpubkey);
364 return ret | checkmsg;
368 /* dump single chain element to console */
369 static void cert_dump_blob(struct blob_attr *cert[CERT_ATTR_MAX]) {
372 for (i = 0; i < CERT_ATTR_MAX; i++) {
373 struct blob_attr *v = cert[i];
378 switch(cert_policy[i].type) {
379 case BLOB_ATTR_BINARY:
380 fprintf(stdout, "signature:\n---\n%s---\n", (char *) blob_data(v));
382 case BLOB_ATTR_NESTED:
383 fprintf(stdout, "payload:\n---\n%s\n---\n", blobmsg_format_json_indent(blob_data(v), false, 0));
389 /* dump certfile to console */
390 static int cert_dump(const char *certfile) {
391 struct cert_object *cobj;
392 static LIST_HEAD(certchain);
393 unsigned int count = 0;
395 if (cert_load(certfile, &certchain)) {
396 DPRINTF("cannot parse cert\n");
400 list_for_each_entry(cobj, &certchain, list) {
401 fprintf(stdout, "=== CHAIN ELEMENT %02u ===\n", ++count);
402 cert_dump_blob(cobj->cert);
408 /* issue an auth certificate for pubkey */
409 static int cert_issue(const char *certfile, const char *pubkeyfile, const char *seckeyfile) {
410 struct blob_buf certbuf;
411 struct blob_buf payloadbuf;
419 char fname[256], sfname[256];
421 char tmpdir[] = "/tmp/ucert-XXXXXX";
423 pkf = fopen(pubkeyfile, "r");
427 pklen = fread(pkb, 1, 512, pkf);
435 if (usign_f_pubkey(pkfp, pubkeyfile))
438 gettimeofday(&tv, NULL);
440 if (mkdtemp(tmpdir) == NULL)
443 while (revoker >= 0) {
444 blob_buf_init(&payloadbuf, 0);
445 c = blobmsg_open_table(&payloadbuf, "ucert");
446 blobmsg_add_u32(&payloadbuf, "certtype", revoker?CERTTYPE_REVOKE:CERTTYPE_AUTH);
447 blobmsg_add_u64(&payloadbuf, "validfrom", tv.tv_sec);
449 blobmsg_add_u64(&payloadbuf, "expiresat", tv.tv_sec + 60 * 60 * 24 * 365);
450 blobmsg_add_string(&payloadbuf, "pubkey", pkb);
452 blobmsg_add_string(&payloadbuf, "fingerprint", pkfp);
455 blobmsg_close_table(&payloadbuf, c);
457 snprintf(fname, sizeof(fname) - 1, "%s/%s", tmpdir, revoker?"revoker":"payload");
458 write_file(fname, blob_data(payloadbuf.head), blob_len(payloadbuf.head), false);
460 snprintf(sfname, sizeof(sfname) - 1, "%s/%s", tmpdir, revoker?"revoker.sig":"payload.sig");
461 if (usign_s(fname, seckeyfile, sfname, quiet))
464 sigf = fopen(sfname, "r");
468 siglen = fread(sigb, 1, 1024, sigf);
478 blob_buf_init(&certbuf, 0);
479 blob_put(&certbuf, CERT_ATTR_SIGNATURE, sigb, siglen);
480 blob_put(&certbuf, CERT_ATTR_PAYLOAD, blob_data(payloadbuf.head), blob_len(payloadbuf.head));
481 snprintf(fname, sizeof(fname) - 1, "%s%s", certfile, revoker?".revoke":"");
482 write_file(fname, certbuf.head, blob_raw_len(certbuf.head), true);
483 blob_buf_free(&certbuf);
484 blob_buf_free(&payloadbuf);
495 /* process revoker certificate */
496 static int cert_process_revoker(const char *certfile, const char *pubkeydir) {
497 static LIST_HEAD(certchain);
498 struct cert_object *cobj;
499 struct blob_attr *containertb[CERT_CT_ATTR_MAX];
500 struct blob_attr *payloadtb[CERT_PL_ATTR_MAX];
510 if (cert_load(certfile, &certchain)) {
511 DPRINTF("cannot parse cert\n");
515 gettimeofday(&tv, NULL);
517 list_for_each_entry(cobj, &certchain, list) {
518 if (!cobj->cert[CERT_ATTR_PAYLOAD])
521 /* blob has payload, verify that using signature */
522 ret = cert_verify_blob(cobj->cert, NULL, pubkeydir);
526 blobmsg_parse(cert_cont_policy,
527 ARRAY_SIZE(cert_cont_policy),
529 blob_data(cobj->cert[CERT_ATTR_PAYLOAD]),
530 blob_len(cobj->cert[CERT_ATTR_PAYLOAD]));
531 if (!containertb[CERT_CT_ATTR_PAYLOAD]) {
532 DPRINTF("no ucert in signed payload\n");
536 blobmsg_parse(cert_payload_policy,
537 ARRAY_SIZE(cert_payload_policy),
539 blobmsg_data(containertb[CERT_CT_ATTR_PAYLOAD]),
540 blobmsg_data_len(containertb[CERT_CT_ATTR_PAYLOAD]));
542 if (!payloadtb[CERT_PL_ATTR_CERTTYPE] ||
543 !payloadtb[CERT_PL_ATTR_VALIDFROMTIME] ||
544 !payloadtb[CERT_PL_ATTR_KEY_FINGERPRINT]) {
545 DPRINTF("missing mandatory ucert attributes\n");
549 certtype = blobmsg_get_u32(payloadtb[CERT_PL_ATTR_CERTTYPE]);
550 validfrom = blobmsg_get_u64(payloadtb[CERT_PL_ATTR_VALIDFROMTIME]);
551 fingerprint = blobmsg_get_string(payloadtb[CERT_PL_ATTR_KEY_FINGERPRINT]);
553 if (certtype != CERTTYPE_REVOKE) {
554 DPRINTF("wrong certificate type\n");
558 if (tv.tv_sec < validfrom) {
562 snprintf(rfname, sizeof(rfname)-1, "%s/%s", pubkeydir, fingerprint);
563 /* check if entry in pubkeydir exists */
564 if (stat(rfname, &st) == 0) {
565 if (_usign_key_is_revoked(fingerprint, pubkeydir)) {
566 DPRINTF("existing revoker deadlink for key %s\n", fingerprint);
570 /* remove any other entry */
575 ret = symlink(".revoked.", rfname);
579 DPRINTF("created revoker deadlink for key %s\n", fingerprint);
585 /* load and verify certfile (and message) */
586 static int cert_verify(const char *certfile, const char *pubkeyfile, const char *pubkeydir, const char *msgfile) {
587 static LIST_HEAD(certchain);
589 if (cert_load(certfile, &certchain)) {
590 DPRINTF("cannot parse cert\n");
594 return chain_verify(msgfile, pubkeyfile, pubkeydir, &certchain);
598 static int usage(const char *cmd)
600 #ifndef UCERT_STRIP_MESSAGES
602 "Usage: %s <command> <options>\n"
605 " -A: append signature (needs -c and -x)\n"
606 " -D: dump (needs -c)\n"
607 " -I: issue cert and revoker (needs -c and -p and -s)\n"
608 #endif /* UCERT_FULL */
609 " -R: process revoker certificate (needs -c and -P)\n"
610 " -V: verify (needs -c and -p|-P, may have -m)\n"
612 " -c <file>: certificate file\n"
613 " -m <file>: message file (verify only)\n"
614 " -p <file>: public key file\n"
615 " -P <path>: public key directory (verify only)\n"
616 " -q: quiet (do not print verification result, use return code only)\n"
618 " -s <file>: secret key file (issue only)\n"
619 " -x <file>: signature file (append only)\n"
620 #endif /* UCERT_FULL */
623 #endif /* UCERT_STRIP_MESSAGES */
627 /* parse command line options and call functions */
628 int main(int argc, char *argv[]) {
630 const char *msgfile = NULL;
631 const char *pubkeyfile = NULL;
632 const char *pubkeydir = NULL;
633 const char *certfile = NULL;
635 const char *sigfile = NULL;
636 const char *seckeyfile = NULL;
640 while ((ch = getopt(argc, argv,
650 return usage(argv[0]);
655 return usage(argv[0]);
660 return usage(argv[0]);
666 return usage(argv[0]);
671 return usage(argv[0]);
675 if (certfile || cmd == CMD_NONE)
676 return usage(argv[0]);
680 if (msgfile || cmd != CMD_VERIFY)
681 return usage(argv[0]);
685 if (pubkeyfile || (cmd != CMD_VERIFY && cmd != CMD_ISSUE) || cmd == CMD_NONE)
686 return usage(argv[0]);
690 if (pubkeydir || (cmd != CMD_VERIFY && cmd != CMD_REVOKE) || cmd == CMD_NONE)
691 return usage(argv[0]);
696 return usage(argv[0]);
701 if (seckeyfile || cmd != CMD_ISSUE || cmd == CMD_NONE)
702 return usage(argv[0]);
706 if (sigfile || cmd != CMD_APPEND || cmd == CMD_NONE)
707 return usage(argv[0]);
712 return usage(argv[0]);
719 if (certfile && sigfile)
720 return cert_append(certfile, sigfile);
722 return usage(argv[0]);
725 return cert_dump(certfile);
727 return usage(argv[0]);
729 if (certfile && pubkeyfile && seckeyfile)
730 return cert_issue(certfile, pubkeyfile, seckeyfile);
732 return usage(argv[0]);
735 if (certfile && pubkeydir)
736 return cert_process_revoker(certfile, pubkeydir);
738 return usage(argv[0]);
740 if (certfile && (pubkeyfile || pubkeydir))
741 return cert_verify(certfile, pubkeyfile, pubkeydir, msgfile);
743 return usage(argv[0]);
745 return usage(argv[0]);
749 return usage(argv[0]);