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
54 * | SIGNATURE | PAYLOAD |
55 * | |[ BLOBMSG CONTAINER ]|
56 * | |[[T,i,v,e,f,pubkey ]]|
64 static const struct blob_attr_info cert_policy[CERT_ATTR_MAX] = {
65 [CERT_ATTR_SIGNATURE] = { .type = BLOB_ATTR_BINARY },
66 [CERT_ATTR_PAYLOAD] = { .type = BLOB_ATTR_NESTED },
74 static const struct blobmsg_policy cert_cont_policy[CERT_CT_ATTR_MAX] = {
75 [CERT_CT_ATTR_PAYLOAD] = { .name = "ucert", .type = BLOBMSG_TYPE_TABLE },
78 enum cert_payload_attr {
79 CERT_PL_ATTR_CERTTYPE,
81 CERT_PL_ATTR_VALIDFROMTIME,
82 CERT_PL_ATTR_EXPIRETIME,
84 CERT_PL_ATTR_KEY_FINGERPRINT,
94 static const struct blobmsg_policy cert_payload_policy[CERT_PL_ATTR_MAX] = {
95 [CERT_PL_ATTR_CERTTYPE] = { .name = "certtype", .type = BLOBMSG_TYPE_INT32 },
96 [CERT_PL_ATTR_CERTID] = { .name = "certid", .type = BLOBMSG_TYPE_INT32 },
97 [CERT_PL_ATTR_VALIDFROMTIME] = { .name = "validfrom", .type = BLOBMSG_TYPE_INT64 },
98 [CERT_PL_ATTR_EXPIRETIME] = { .name = "expiresat", .type = BLOBMSG_TYPE_INT64 },
99 [CERT_PL_ATTR_PUBKEY] = { .name = "pubkey", .type = BLOBMSG_TYPE_STRING },
100 [CERT_PL_ATTR_KEY_FINGERPRINT] = { .name = "fingerprint", .type = BLOBMSG_TYPE_STRING },
103 /* list to store certificate chain at runtime */
105 struct list_head list;
106 struct blob_attr *cert[CERT_ATTR_MAX];
109 /* write buffer to file */
110 static int write_file(const char *filename, void *buf, size_t len, bool append) {
114 f = fopen(filename, append?"a":"w");
118 outlen = fwrite(buf, 1, len, f);
120 return (outlen == len);
123 /* load certfile into list */
124 static int cert_load(const char *certfile, struct list_head *chain) {
126 struct blob_attr *certtb[CERT_ATTR_MAX];
127 struct blob_attr *bufpt;
128 struct cert_object *cobj;
129 char filebuf[CERT_BUF_LEN];
130 int ret = 0, pret = 0;
133 f = fopen(certfile, "r");
137 len = fread(&filebuf, 1, CERT_BUF_LEN - 1, f);
141 ret = ferror(f) || !feof(f);
146 bufpt = (struct blob_attr *)filebuf;
148 pret = blob_parse(bufpt, certtb, cert_policy, CERT_ATTR_MAX);
150 /* no attributes found */
153 if (pos + blob_pad_len(bufpt) > len)
154 /* blob exceeds filebuffer */
157 pos += blob_pad_len(bufpt);
159 if (!certtb[CERT_ATTR_SIGNATURE])
160 /* no signature -> drop */
163 cobj = calloc(1, sizeof(*cobj));
164 cobj->cert[CERT_ATTR_SIGNATURE] = blob_memdup(certtb[CERT_ATTR_SIGNATURE]);
165 if (certtb[CERT_ATTR_PAYLOAD])
166 cobj->cert[CERT_ATTR_PAYLOAD] = blob_memdup(certtb[CERT_ATTR_PAYLOAD]);
168 list_add_tail(&cobj->list, chain);
170 bufpt = blob_next(bufpt);
171 /* repeat parsing while there is still enough remaining data in buffer */
172 } while(len > pos + sizeof(struct blob_attr));
177 /* append signature to certfile */
178 static int cert_append(const char *certfile, const char *sigfile) {
180 char filebuf[CERT_BUF_LEN];
181 struct blob_buf sigbuf;
185 fs = fopen(sigfile, "r");
189 len = fread(&filebuf, 1, CERT_BUF_LEN - 1, fs);
190 ret = ferror(fs) || !feof(fs) || (len < 64);
195 blob_buf_init(&sigbuf, 0);
196 blob_put(&sigbuf, CERT_ATTR_SIGNATURE, filebuf, len);
197 ret = write_file(certfile, sigbuf.head, blob_raw_len(sigbuf.head), true);
198 blob_buf_free(&sigbuf);
202 /* verify the signature of a single chain element */
203 static int cert_verify_blob(struct blob_attr *cert[CERT_ATTR_MAX],
204 const char *pubkeyfile, const char *pubkeydir) {
206 char msgfname[256], sigfname[256];
208 char tmpdir[] = "/tmp/ucert-XXXXXX";
210 if (mkdtemp(tmpdir) == NULL)
213 snprintf(msgfname, sizeof(msgfname) - 1, "%s/%s", tmpdir, "payload");
214 snprintf(sigfname, sizeof(sigfname) - 1, "%s/%s", tmpdir, "payload.sig");
216 for (i = 0; i < CERT_ATTR_MAX; i++) {
217 struct blob_attr *v = cert[i];
222 switch(cert_policy[i].type) {
223 case BLOB_ATTR_BINARY:
224 write_file(sigfname, blob_data(v), blob_len(v), false);
226 case BLOB_ATTR_NESTED:
227 write_file(msgfname, blob_data(v), blob_len(v), false);
232 ret = usign_v(msgfname, pubkeyfile, pubkeydir, sigfname, quiet);
241 /* verify cert chain (and message) */
242 static int chain_verify(const char *msgfile, const char *pubkeyfile,
243 const char *pubkeydir, struct list_head *chain) {
244 struct cert_object *cobj;
245 struct blob_attr *containertb[CERT_CT_ATTR_MAX];
246 struct blob_attr *payloadtb[CERT_PL_ATTR_MAX];
247 char tmpdir[] = "/tmp/ucert-XXXXXX";
248 char chainedpubkey[256] = {0};
249 char chainedfp[17] = {0};
250 char extsigfile[256] = {0};
254 if (mkdtemp(tmpdir) == NULL)
260 list_for_each_entry(cobj, chain, list) {
261 /* blob has payload, verify that using signature */
262 if (cobj->cert[CERT_ATTR_PAYLOAD]) {
268 ret = cert_verify_blob(cobj->cert, chainedpubkey[0]?chainedpubkey:pubkeyfile, pubkeydir);
270 goto clean_and_return;
272 blobmsg_parse(cert_cont_policy,
273 ARRAY_SIZE(cert_cont_policy),
275 blob_data(cobj->cert[CERT_ATTR_PAYLOAD]),
276 blob_len(cobj->cert[CERT_ATTR_PAYLOAD]));
277 if (!containertb[CERT_CT_ATTR_PAYLOAD]) {
280 fprintf(stderr, "no ucert in signed payload\n");
281 goto clean_and_return;
283 blobmsg_parse(cert_payload_policy,
284 ARRAY_SIZE(cert_payload_policy),
286 blobmsg_data(containertb[CERT_CT_ATTR_PAYLOAD]),
287 blobmsg_data_len(containertb[CERT_CT_ATTR_PAYLOAD]));
289 if (!payloadtb[CERT_PL_ATTR_CERTTYPE] ||
290 !payloadtb[CERT_PL_ATTR_VALIDFROMTIME] ||
291 !payloadtb[CERT_PL_ATTR_EXPIRETIME] ||
292 !payloadtb[CERT_PL_ATTR_PUBKEY]) {
295 fprintf(stderr, "missing mandatory ucert attributes\n");
296 goto clean_and_return;
298 certtype = blobmsg_get_u32(payloadtb[CERT_PL_ATTR_CERTTYPE]);
299 validfrom = blobmsg_get_u64(payloadtb[CERT_PL_ATTR_VALIDFROMTIME]);
300 expiresat = blobmsg_get_u64(payloadtb[CERT_PL_ATTR_EXPIRETIME]);
302 if (certtype != CERTTYPE_AUTH) {
305 fprintf(stderr, "wrong certificate type\n");
306 goto clean_and_return;
309 gettimeofday(&tv, NULL);
310 if (tv.tv_sec < validfrom ||
311 tv.tv_sec >= expiresat) {
314 fprintf(stderr, "certificate expired\n");
315 goto clean_and_return;
318 snprintf(chainedpubkey, sizeof(chainedpubkey) - 1, "%s/%s", tmpdir, "chained-pubkey");
319 write_file(chainedpubkey,
320 blobmsg_data(payloadtb[CERT_PL_ATTR_PUBKEY]),
321 blobmsg_data_len(payloadtb[CERT_PL_ATTR_PUBKEY]),
324 if (usign_f_pubkey(chainedfp, chainedpubkey)) {
326 fprintf(stderr, "cannot get fingerprint for chained key\n");
328 goto clean_and_return;
330 if (pubkeydir && _usign_key_is_revoked(chainedfp, pubkeydir)) {
332 fprintf(stderr, "key %s has been revoked!\n", chainedfp);
334 goto clean_and_return;
337 /* blob doesn't have payload, verify message using signature */
339 snprintf(extsigfile, sizeof(extsigfile) - 1, "%s/%s", tmpdir, "ext-sig");
340 write_file(extsigfile,
341 blob_data(cobj->cert[CERT_ATTR_SIGNATURE]),
342 blob_len(cobj->cert[CERT_ATTR_SIGNATURE]),
344 checkmsg = ret = usign_v(msgfile,
345 chainedpubkey[0]?chainedpubkey:pubkeyfile,
346 pubkeydir, extsigfile, quiet);
350 fprintf(stderr, "stray trailing signature without anything to verify!\n");
356 if (checkmsg == -1 && !quiet)
357 fprintf(stderr, "missing signature to verify message!\n");
360 if (chainedpubkey[0])
361 unlink(chainedpubkey);
363 return ret | checkmsg;
366 /* dump single chain element to console */
367 static void cert_dump_blob(struct blob_attr *cert[CERT_ATTR_MAX]) {
370 for (i = 0; i < CERT_ATTR_MAX; i++) {
371 struct blob_attr *v = cert[i];
376 switch(cert_policy[i].type) {
377 case BLOB_ATTR_BINARY:
378 fprintf(stdout, "signature:\n---\n%s---\n", (char *) blob_data(v));
380 case BLOB_ATTR_NESTED:
381 fprintf(stdout, "payload:\n---\n%s\n---\n", blobmsg_format_json_indent(blob_data(v), false, 0));
387 /* dump certfile to console */
388 static int cert_dump(const char *certfile) {
389 struct cert_object *cobj;
390 static LIST_HEAD(certchain);
391 unsigned int count = 0;
393 if (cert_load(certfile, &certchain)) {
395 fprintf(stderr, "cannot parse cert\n");
399 list_for_each_entry(cobj, &certchain, list) {
400 fprintf(stdout, "=== CHAIN ELEMENT %02u ===\n", ++count);
401 cert_dump_blob(cobj->cert);
407 /* issue an auth certificate for pubkey */
408 static int cert_issue(const char *certfile, const char *pubkeyfile, const char *seckeyfile) {
409 struct blob_buf certbuf;
410 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);
494 /* process revoker certificate */
495 static int cert_process_revoker(const char *certfile, const char *pubkeydir) {
496 static LIST_HEAD(certchain);
497 struct cert_object *cobj;
498 struct blob_attr *containertb[CERT_CT_ATTR_MAX];
499 struct blob_attr *payloadtb[CERT_PL_ATTR_MAX];
509 if (cert_load(certfile, &certchain)) {
511 fprintf(stderr, "cannot parse cert\n");
515 list_for_each_entry(cobj, &certchain, list) {
516 if (!cobj->cert[CERT_ATTR_PAYLOAD])
519 /* blob has payload, verify that using signature */
520 ret = cert_verify_blob(cobj->cert, NULL, pubkeydir);
524 blobmsg_parse(cert_cont_policy,
525 ARRAY_SIZE(cert_cont_policy),
527 blob_data(cobj->cert[CERT_ATTR_PAYLOAD]),
528 blob_len(cobj->cert[CERT_ATTR_PAYLOAD]));
529 if (!containertb[CERT_CT_ATTR_PAYLOAD]) {
531 fprintf(stderr, "no ucert in signed payload\n");
535 blobmsg_parse(cert_payload_policy,
536 ARRAY_SIZE(cert_payload_policy),
538 blobmsg_data(containertb[CERT_CT_ATTR_PAYLOAD]),
539 blobmsg_data_len(containertb[CERT_CT_ATTR_PAYLOAD]));
541 if (!payloadtb[CERT_PL_ATTR_CERTTYPE] ||
542 !payloadtb[CERT_PL_ATTR_VALIDFROMTIME] ||
543 !payloadtb[CERT_PL_ATTR_KEY_FINGERPRINT]) {
545 fprintf(stderr, "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) {
555 fprintf(stderr, "wrong certificate type\n");
559 gettimeofday(&tv, NULL);
560 if (tv.tv_sec < validfrom) {
564 snprintf(rfname, sizeof(rfname)-1, "%s/%s", pubkeydir, fingerprint);
565 /* check if entry in pubkeydir exists */
566 if (stat(rfname, &st) == 0) {
567 if (_usign_key_is_revoked(fingerprint, pubkeydir)) {
569 fprintf(stdout, "existing revoker deadlink for key %s\n", fingerprint);
573 /* remove any other entry */
578 ret = symlink(".revoked.", rfname);
583 fprintf(stdout, "created revoker deadlink for key %s\n", fingerprint);
589 /* load and verify certfile (and message) */
590 static int cert_verify(const char *certfile, const char *pubkeyfile, const char *pubkeydir, const char *msgfile) {
591 static LIST_HEAD(certchain);
593 if (cert_load(certfile, &certchain)) {
595 fprintf(stderr, "cannot parse cert\n");
599 return chain_verify(msgfile, pubkeyfile, pubkeydir, &certchain);
603 static int usage(const char *cmd)
606 "Usage: %s <command> <options>\n"
608 " -A: append signature (needs -c and -x)\n"
609 " -D: dump (needs -c)\n"
610 " -I: issue cert and revoker (needs -c and -p and -s)\n"
611 " -R: process revoker certificate (needs -c and -P)\n"
612 " -V: verify (needs -c and -p|-P, may have -m)\n"
614 " -c <file>: certificate file\n"
615 " -m <file>: message file (verify only)\n"
616 " -p <file>: public key file\n"
617 " -P <path>: public key directory (verify only)\n"
618 " -q: quiet (do not print verification result, use return code only)\n"
619 " -s <file>: secret key file (issue only)\n"
620 " -x <file>: signature file\n"
626 /* parse command line options and call functions */
627 int main(int argc, char *argv[]) {
629 const char *msgfile = NULL;
630 const char *sigfile = NULL;
631 const char *pubkeyfile = NULL;
632 const char *pubkeydir = NULL;
633 const char *certfile = NULL;
634 const char *seckeyfile = NULL;
637 while ((ch = getopt(argc, argv, "ADIRVc:m:p:P:qs:x:")) != -1) {
641 return usage(argv[0]);
646 return usage(argv[0]);
651 return usage(argv[0]);
656 return usage(argv[0]);
661 return usage(argv[0]);
665 if (certfile || cmd == CMD_NONE)
666 return usage(argv[0]);
670 if (msgfile || cmd != CMD_VERIFY)
671 return usage(argv[0]);
675 if (pubkeyfile || (cmd != CMD_VERIFY && cmd != CMD_ISSUE) || cmd == CMD_NONE)
676 return usage(argv[0]);
680 if (pubkeydir || (cmd != CMD_VERIFY && cmd != CMD_REVOKE) || cmd == CMD_NONE)
681 return usage(argv[0]);
686 return usage(argv[0]);
690 if (seckeyfile || cmd != CMD_ISSUE || cmd == CMD_NONE)
691 return usage(argv[0]);
695 if (sigfile || cmd != CMD_APPEND || cmd == CMD_NONE)
696 return usage(argv[0]);
700 return usage(argv[0]);
706 if (certfile && sigfile)
707 return cert_append(certfile, sigfile);
709 return usage(argv[0]);
712 return cert_dump(certfile);
714 return usage(argv[0]);
716 if (certfile && pubkeyfile && seckeyfile)
717 return cert_issue(certfile, pubkeyfile, seckeyfile);
719 return usage(argv[0]);
721 if (certfile && pubkeydir)
722 return cert_process_revoker(certfile, pubkeydir);
724 return usage(argv[0]);
726 if (certfile && (pubkeyfile || pubkeydir))
727 return cert_verify(certfile, pubkeyfile, pubkeydir, msgfile);
729 return usage(argv[0]);
731 return usage(argv[0]);
735 return usage(argv[0]);