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
57 static const struct blob_attr_info cert_policy[CERT_ATTR_MAX] = {
58 [CERT_ATTR_SIGNATURE] = { .type = BLOB_ATTR_BINARY },
59 [CERT_ATTR_PAYLOAD] = { .type = BLOB_ATTR_NESTED },
67 static const struct blobmsg_policy cert_cont_policy[CERT_CT_ATTR_MAX] = {
68 [CERT_CT_ATTR_PAYLOAD] = { .name = "ucert", .type = BLOBMSG_TYPE_TABLE },
71 enum cert_payload_attr {
72 CERT_PL_ATTR_CERTTYPE,
74 CERT_PL_ATTR_VALIDFROMTIME,
75 CERT_PL_ATTR_EXPIRETIME,
77 CERT_PL_ATTR_KEY_FINGERPRINT,
87 static const struct blobmsg_policy cert_payload_policy[CERT_PL_ATTR_MAX] = {
88 [CERT_PL_ATTR_CERTTYPE] = { .name = "certtype", .type = BLOBMSG_TYPE_INT32 },
89 [CERT_PL_ATTR_CERTID] = { .name = "certid", .type = BLOBMSG_TYPE_INT32 },
90 [CERT_PL_ATTR_VALIDFROMTIME] = { .name = "validfrom", .type = BLOBMSG_TYPE_INT64 },
91 [CERT_PL_ATTR_EXPIRETIME] = { .name = "expiresat", .type = BLOBMSG_TYPE_INT64 },
92 [CERT_PL_ATTR_PUBKEY] = { .name = "pubkey", .type = BLOBMSG_TYPE_STRING },
93 [CERT_PL_ATTR_KEY_FINGERPRINT] = { .name = "fingerprint", .type = BLOBMSG_TYPE_STRING },
97 struct list_head list;
98 struct blob_attr *cert[CERT_ATTR_MAX];
101 static int write_file(const char *filename, void *buf, size_t len, bool append) {
105 f = fopen(filename, append?"a":"w");
109 outlen = fwrite(buf, 1, len, f);
111 return (outlen == len);
114 static int cert_load(const char *certfile, struct list_head *chain) {
116 struct blob_attr *certtb[CERT_ATTR_MAX];
117 struct blob_attr *bufpt;
118 struct cert_object *cobj;
119 char filebuf[CERT_BUF_LEN];
120 int ret = 0, pret = 0;
123 f = fopen(certfile, "r");
127 len = fread(&filebuf, 1, CERT_BUF_LEN - 1, f);
131 ret = ferror(f) || !feof(f);
136 bufpt = (struct blob_attr *)filebuf;
138 pret = blob_parse(bufpt, certtb, cert_policy, CERT_ATTR_MAX);
140 /* no attributes found */
143 if (pos + blob_pad_len(bufpt) > len)
144 /* blob exceeds filebuffer */
147 pos += blob_pad_len(bufpt);
149 cobj = calloc(1, sizeof(*cobj));
150 memcpy(cobj->cert, &certtb, sizeof(certtb));
151 list_add_tail(&cobj->list, chain);
153 bufpt = blob_next(bufpt);
154 /* repeat parsing while there is still enough remaining data in buffer */
155 } while(len > pos + sizeof(struct blob_attr));
160 static int cert_append(const char *certfile, const char *sigfile) {
162 char filebuf[CERT_BUF_LEN];
163 struct blob_buf sigbuf;
167 fs = fopen(sigfile, "r");
171 len = fread(&filebuf, 1, CERT_BUF_LEN - 1, fs);
172 ret = ferror(fs) || !feof(fs) || (len < 64);
177 blob_buf_init(&sigbuf, 0);
178 blob_put(&sigbuf, CERT_ATTR_SIGNATURE, filebuf, len);
179 ret = write_file(certfile, sigbuf.head, blob_raw_len(sigbuf.head), true);
180 blob_buf_free(&sigbuf);
184 static int cert_verify_blob(struct blob_attr *cert[CERT_ATTR_MAX],
185 const char *pubkeyfile, const char *pubkeydir) {
187 char msgfname[256], sigfname[256];
189 char tmpdir[] = "/tmp/ucert-XXXXXX";
191 if (mkdtemp(tmpdir) == NULL)
194 snprintf(msgfname, sizeof(msgfname) - 1, "%s/%s", tmpdir, "payload");
195 snprintf(sigfname, sizeof(sigfname) - 1, "%s/%s", tmpdir, "payload.sig");
197 for (i = 0; i < CERT_ATTR_MAX; i++) {
198 struct blob_attr *v = cert[i];
203 switch(cert_policy[i].type) {
204 case BLOB_ATTR_BINARY:
205 write_file(sigfname, blob_data(v), blob_len(v), false);
207 case BLOB_ATTR_NESTED:
208 write_file(msgfname, blob_data(v), blob_len(v), false);
213 ret = usign_v(msgfname, pubkeyfile, pubkeydir, sigfname, quiet);
222 static int chain_verify(const char *msgfile, const char *pubkeyfile,
223 const char *pubkeydir, struct list_head *chain) {
224 struct cert_object *cobj;
225 struct blob_attr *containertb[CERT_CT_ATTR_MAX];
226 struct blob_attr *payloadtb[CERT_PL_ATTR_MAX];
227 char tmpdir[] = "/tmp/ucert-XXXXXX";
228 char chainedpubkey[256] = {0};
229 char chainedfp[17] = {0};
230 char extsigfile[256] = {0};
234 if (mkdtemp(tmpdir) == NULL)
240 list_for_each_entry(cobj, chain, list) {
241 /* blob has payload, verify that using signature */
242 if (cobj->cert[CERT_ATTR_PAYLOAD]) {
248 ret = cert_verify_blob(cobj->cert, chainedpubkey[0]?chainedpubkey:pubkeyfile, pubkeydir);
250 goto clean_and_return;
252 blobmsg_parse(cert_cont_policy,
253 ARRAY_SIZE(cert_cont_policy),
255 blob_data(cobj->cert[CERT_ATTR_PAYLOAD]),
256 blob_len(cobj->cert[CERT_ATTR_PAYLOAD]));
257 if (!containertb[CERT_CT_ATTR_PAYLOAD]) {
259 fprintf(stderr, "no ucert in signed payload\n");
260 goto clean_and_return;
262 blobmsg_parse(cert_payload_policy,
263 ARRAY_SIZE(cert_payload_policy),
265 blobmsg_data(containertb[CERT_CT_ATTR_PAYLOAD]),
266 blobmsg_data_len(containertb[CERT_CT_ATTR_PAYLOAD]));
268 if (!payloadtb[CERT_PL_ATTR_CERTTYPE] ||
269 !payloadtb[CERT_PL_ATTR_VALIDFROMTIME] ||
270 !payloadtb[CERT_PL_ATTR_EXPIRETIME] ||
271 !payloadtb[CERT_PL_ATTR_PUBKEY]) {
273 fprintf(stderr, "missing mandatory ucert attributes\n");
274 goto clean_and_return;
276 certtype = blobmsg_get_u32(payloadtb[CERT_PL_ATTR_CERTTYPE]);
277 validfrom = blobmsg_get_u64(payloadtb[CERT_PL_ATTR_VALIDFROMTIME]);
278 expiresat = blobmsg_get_u64(payloadtb[CERT_PL_ATTR_EXPIRETIME]);
280 if (certtype != CERTTYPE_AUTH) {
282 fprintf(stderr, "wrong certificate type\n");
283 goto clean_and_return;
286 gettimeofday(&tv, NULL);
287 if (tv.tv_sec < validfrom ||
288 tv.tv_sec >= expiresat) {
290 fprintf(stderr, "certificate expired\n");
291 goto clean_and_return;
294 snprintf(chainedpubkey, sizeof(chainedpubkey) - 1, "%s/%s", tmpdir, "chained-pubkey");
295 write_file(chainedpubkey,
296 blobmsg_data(payloadtb[CERT_PL_ATTR_PUBKEY]),
297 blobmsg_data_len(payloadtb[CERT_PL_ATTR_PUBKEY]),
300 if (usign_f_pubkey(chainedfp, chainedpubkey)) {
302 fprintf(stderr, "cannot get fingerprint for chained key\n");
304 goto clean_and_return;
306 if (pubkeydir && _usign_key_is_revoked(chainedfp, pubkeydir)) {
308 fprintf(stderr, "key %s has been revoked!\n", chainedfp);
310 goto clean_and_return;
313 /* blob doesn't have payload, verify message using signature */
315 snprintf(extsigfile, sizeof(extsigfile) - 1, "%s/%s", tmpdir, "ext-sig");
316 write_file(extsigfile,
317 blob_data(cobj->cert[CERT_ATTR_SIGNATURE]),
318 blob_len(cobj->cert[CERT_ATTR_SIGNATURE]),
320 checkmsg = ret = usign_v(msgfile,
321 chainedpubkey[0]?chainedpubkey:pubkeyfile,
322 pubkeydir, extsigfile, quiet);
325 fprintf(stderr, "stray trailing signature without anything to verify!\n");
332 fprintf(stderr, "missing signature to verify message!\n");
335 if (chainedpubkey[0])
336 unlink(chainedpubkey);
338 return ret | checkmsg;
341 static void cert_dump_blob(struct blob_attr *cert[CERT_ATTR_MAX]) {
344 for (i = 0; i < CERT_ATTR_MAX; i++) {
345 struct blob_attr *v = cert[i];
350 switch(cert_policy[i].type) {
351 case BLOB_ATTR_BINARY:
352 fprintf(stdout, "signature:\n---\n%s---\n", (char *) blob_data(v));
354 case BLOB_ATTR_NESTED:
355 fprintf(stdout, "payload:\n---\n%s\n---\n", blobmsg_format_json_indent(blob_data(v), false, 0));
361 static int cert_dump(const char *certfile) {
362 struct cert_object *cobj;
363 static LIST_HEAD(certchain);
364 unsigned int count = 0;
366 if (cert_load(certfile, &certchain)) {
367 fprintf(stderr, "cannot parse cert\n");
371 list_for_each_entry(cobj, &certchain, list) {
372 fprintf(stderr, "=== CHAIN ELEMENT %02u ===\n", ++count);
373 cert_dump_blob(cobj->cert);
374 fprintf(stderr, "========================\n");
380 static int cert_issue(const char *certfile, const char *pubkeyfile, const char *seckeyfile) {
381 struct blob_buf certbuf;
382 struct blob_buf payloadbuf;
391 char fname[256], sfname[256];
393 char tmpdir[] = "/tmp/ucert-XXXXXX";
395 if (stat(certfile, &st) == 0) {
396 fprintf(stderr, "certfile %s exists, won't overwrite.\n", certfile);
400 pkf = fopen(pubkeyfile, "r");
404 pklen = fread(pkb, 1, 512, pkf);
412 if (usign_f_pubkey(pkfp, pubkeyfile))
415 gettimeofday(&tv, NULL);
417 if (mkdtemp(tmpdir) == NULL)
420 while (revoker >= 0) {
421 blob_buf_init(&payloadbuf, 0);
422 c = blobmsg_open_table(&payloadbuf, "ucert");
423 blobmsg_add_u32(&payloadbuf, "certtype", revoker?CERTTYPE_REVOKE:CERTTYPE_AUTH);
424 blobmsg_add_u64(&payloadbuf, "validfrom", tv.tv_sec);
426 blobmsg_add_u64(&payloadbuf, "expiresat", tv.tv_sec + 60 * 60 * 24 * 365);
427 blobmsg_add_string(&payloadbuf, "pubkey", pkb);
429 blobmsg_add_string(&payloadbuf, "fingerprint", pkfp);
432 blobmsg_close_table(&payloadbuf, c);
434 snprintf(fname, sizeof(fname) - 1, "%s/%s", tmpdir, revoker?"revoker":"payload");
435 write_file(fname, blob_data(payloadbuf.head), blob_len(payloadbuf.head), false);
437 snprintf(sfname, sizeof(sfname) - 1, "%s/%s", tmpdir, revoker?"revoker.sig":"payload.sig");
438 if (usign_s(fname, seckeyfile, sfname, quiet))
441 sigf = fopen(sfname, "r");
445 siglen = fread(sigb, 1, 1024, sigf);
455 blob_buf_init(&certbuf, 0);
456 blob_put(&certbuf, CERT_ATTR_SIGNATURE, sigb, siglen);
457 blob_put(&certbuf, CERT_ATTR_PAYLOAD, blob_data(payloadbuf.head), blob_len(payloadbuf.head));
458 snprintf(fname, sizeof(fname) - 1, "%s%s", certfile, revoker?".revoke":"");
459 write_file(fname, certbuf.head, blob_raw_len(certbuf.head), false);
460 blob_buf_free(&certbuf);
461 blob_buf_free(&payloadbuf);
471 static int cert_process_revoker(const char *certfile, const char *pubkeydir) {
472 static LIST_HEAD(certchain);
473 struct cert_object *cobj;
474 struct blob_attr *containertb[CERT_CT_ATTR_MAX];
475 struct blob_attr *payloadtb[CERT_PL_ATTR_MAX];
485 if (cert_load(certfile, &certchain)) {
486 fprintf(stderr, "cannot parse cert\n");
490 list_for_each_entry(cobj, &certchain, list) {
491 /* blob has payload, verify that using signature */
492 if (!cobj->cert[CERT_ATTR_PAYLOAD])
494 ret = cert_verify_blob(cobj->cert, NULL, pubkeydir);
498 blobmsg_parse(cert_cont_policy,
499 ARRAY_SIZE(cert_cont_policy),
501 blob_data(cobj->cert[CERT_ATTR_PAYLOAD]),
502 blob_len(cobj->cert[CERT_ATTR_PAYLOAD]));
503 if (!containertb[CERT_CT_ATTR_PAYLOAD]) {
504 fprintf(stderr, "no ucert in signed payload\n");
508 blobmsg_parse(cert_payload_policy,
509 ARRAY_SIZE(cert_payload_policy),
511 blobmsg_data(containertb[CERT_CT_ATTR_PAYLOAD]),
512 blobmsg_data_len(containertb[CERT_CT_ATTR_PAYLOAD]));
514 if (!payloadtb[CERT_PL_ATTR_CERTTYPE] ||
515 !payloadtb[CERT_PL_ATTR_VALIDFROMTIME] ||
516 !payloadtb[CERT_PL_ATTR_KEY_FINGERPRINT]) {
517 fprintf(stderr, "missing mandatory ucert attributes\n");
521 certtype = blobmsg_get_u32(payloadtb[CERT_PL_ATTR_CERTTYPE]);
522 validfrom = blobmsg_get_u64(payloadtb[CERT_PL_ATTR_VALIDFROMTIME]);
523 fingerprint = blobmsg_get_string(payloadtb[CERT_PL_ATTR_KEY_FINGERPRINT]);
525 if (certtype != CERTTYPE_REVOKE) {
526 fprintf(stderr, "wrong certificate type\n");
530 gettimeofday(&tv, NULL);
531 if (tv.tv_sec < validfrom) {
535 snprintf(rfname, sizeof(rfname)-1, "%s/%s", pubkeydir, fingerprint);
536 /* check if entry in pubkeydir exists */
537 if (stat(rfname, &st) == 0) {
538 if (_usign_key_is_revoked(fingerprint, pubkeydir)) {
540 fprintf(stdout, "existing revoker deadlink for key %s\n", fingerprint);
544 /* remove any other entry */
549 ret = symlink(".revoked.", rfname);
554 fprintf(stdout, "created revoker deadlink for key %s\n", fingerprint);
560 static int cert_verify(const char *certfile, const char *pubkeyfile, const char *pubkeydir, const char *msgfile) {
561 static LIST_HEAD(certchain);
563 if (cert_load(certfile, &certchain)) {
564 fprintf(stderr, "cannot parse cert\n");
568 return chain_verify(msgfile, pubkeyfile, pubkeydir, &certchain);
571 static int usage(const char *cmd)
574 "Usage: %s <command> <options>\n"
576 " -A: append signature (needs -c and -x)\n"
577 " -D: dump (needs -c)\n"
578 " -I: issue cert and revoker (needs -c and -p and -s)\n"
579 " -R: process revoker certificate (needs -c and -P)\n"
580 " -V: verify (needs -c and -p|-P, may have -m)\n"
582 " -c <file>: certificate file\n"
583 " -m <file>: message file (verify only)\n"
584 " -p <file>: public key file\n"
585 " -P <path>: public key directory (verify only)\n"
586 " -q: quiet (do not print verification result, use return code only)\n"
587 " -s <file>: secret key file (issue only)\n"
588 " -x <file>: signature file\n"
594 int main(int argc, char *argv[]) {
596 const char *msgfile = NULL;
597 const char *sigfile = NULL;
598 const char *pubkeyfile = NULL;
599 const char *pubkeydir = NULL;
600 const char *certfile = NULL;
601 const char *seckeyfile = NULL;
604 while ((ch = getopt(argc, argv, "ADIRVc:m:p:P:qs:x:")) != -1) {
643 return usage(argv[0]);
649 if (certfile && sigfile)
650 return cert_append(certfile, sigfile);
652 return usage(argv[0]);
655 return cert_dump(certfile);
657 return usage(argv[0]);
659 if (certfile && pubkeyfile && seckeyfile)
660 return cert_issue(certfile, pubkeyfile, seckeyfile);
662 return usage(argv[0]);
664 if (certfile && pubkeydir)
665 return cert_process_revoker(certfile, pubkeydir);
667 return usage(argv[0]);
669 if (certfile && (pubkeyfile || pubkeydir))
670 return cert_verify(certfile, pubkeyfile, pubkeydir, msgfile);
672 return usage(argv[0]);
674 return usage(argv[0]);
678 return usage(argv[0]);