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.
30 #include <json-c/json.h>
31 #include <libubox/blob.h>
32 #include <libubox/utils.h>
33 #include <libubox/list.h>
34 #include <libubox/vlist.h>
35 #include <libubox/blobmsg_json.h>
39 #define CERT_BUF_LEN 4096
51 #ifndef UCERT_STRIP_MESSAGES
52 #define DPRINTF(format, ...) \
55 fprintf(stderr, "%s(%d): " format, __func__, __LINE__, ## __VA_ARGS__); \
58 #define DPRINTF(format, ...) do { } while (0)
64 * | SIGNATURE | PAYLOAD |
65 * | |[ BLOBMSG CONTAINER ]|
66 * | |[[T,i,v,e,f,pubkey ]]|
74 static const struct blob_attr_info cert_policy
[CERT_ATTR_MAX
] = {
75 [CERT_ATTR_SIGNATURE
] = { .type
= BLOB_ATTR_BINARY
},
76 [CERT_ATTR_PAYLOAD
] = { .type
= BLOB_ATTR_NESTED
},
84 static const struct blobmsg_policy cert_cont_policy
[CERT_CT_ATTR_MAX
] = {
85 [CERT_CT_ATTR_PAYLOAD
] = { .name
= "ucert", .type
= BLOBMSG_TYPE_TABLE
},
88 enum cert_payload_attr
{
89 CERT_PL_ATTR_CERTTYPE
,
91 CERT_PL_ATTR_VALIDFROMTIME
,
92 CERT_PL_ATTR_EXPIRETIME
,
94 CERT_PL_ATTR_KEY_FINGERPRINT
,
104 static const struct blobmsg_policy cert_payload_policy
[CERT_PL_ATTR_MAX
] = {
105 [CERT_PL_ATTR_CERTTYPE
] = { .name
= "certtype", .type
= BLOBMSG_TYPE_INT32
},
106 [CERT_PL_ATTR_CERTID
] = { .name
= "certid", .type
= BLOBMSG_TYPE_INT32
},
107 [CERT_PL_ATTR_VALIDFROMTIME
] = { .name
= "validfrom", .type
= BLOBMSG_TYPE_INT64
},
108 [CERT_PL_ATTR_EXPIRETIME
] = { .name
= "expiresat", .type
= BLOBMSG_TYPE_INT64
},
109 [CERT_PL_ATTR_PUBKEY
] = { .name
= "pubkey", .type
= BLOBMSG_TYPE_STRING
},
110 [CERT_PL_ATTR_KEY_FINGERPRINT
] = { .name
= "fingerprint", .type
= BLOBMSG_TYPE_STRING
},
113 /* list to store certificate chain at runtime */
115 struct list_head list
;
116 struct blob_attr
*cert
[CERT_ATTR_MAX
];
119 /* write buffer to file */
120 static bool write_file(const char *filename
, void *buf
, size_t len
, bool append
) {
124 f
= fopen(filename
, append
?"a":"w");
128 outlen
= fwrite(buf
, 1, len
, f
);
130 return (outlen
== len
);
133 /* reads a whole file to a buffer - returns -1 on errors and sets errno */
134 static ssize_t
read_file(const char *filename
, void *buf
, size_t len
, size_t minlen
) {
138 f
= fopen(filename
, "r");
142 ret
= fread(buf
, 1, len
, f
);
144 /* Ensure that feof() yields the correct result when the file is exactly
150 } else if (!feof(f
)) {
153 } else if ((size_t)ret
< minlen
) {
162 /* load certfile into list */
163 static int cert_load(const char *certfile
, struct list_head
*chain
) {
164 struct blob_attr
*certtb
[CERT_ATTR_MAX
];
165 struct blob_attr
*bufpt
;
166 struct cert_object
*cobj
;
167 char filebuf
[CERT_BUF_LEN
];
168 int ret
= 0, pret
= 0;
172 len
= read_file(certfile
, filebuf
, sizeof(filebuf
) - 1, 0);
175 perror("Unable to load certificate file");
179 bufpt
= (struct blob_attr
*)filebuf
;
181 pret
= blob_parse_untrusted(bufpt
, len
, certtb
, cert_policy
, CERT_ATTR_MAX
);
183 /* no attributes found */
186 if (pos
+ blob_pad_len(bufpt
) > (size_t) len
)
187 /* blob exceeds filebuffer */
190 pos
+= blob_pad_len(bufpt
);
192 if (!certtb
[CERT_ATTR_SIGNATURE
])
193 /* no signature -> drop */
196 cobj
= calloc(1, sizeof(*cobj
));
197 cobj
->cert
[CERT_ATTR_SIGNATURE
] = blob_memdup(certtb
[CERT_ATTR_SIGNATURE
]);
198 if (certtb
[CERT_ATTR_PAYLOAD
])
199 cobj
->cert
[CERT_ATTR_PAYLOAD
] = blob_memdup(certtb
[CERT_ATTR_PAYLOAD
]);
201 list_add_tail(&cobj
->list
, chain
);
203 /* repeat parsing while there is still enough remaining data in buffer */
204 } while((size_t) len
> pos
+ sizeof(struct blob_attr
) && (bufpt
= blob_next(bufpt
)));
210 /* append signature to certfile */
211 static int cert_append(const char *certfile
, const char *sigfile
) {
212 char filebuf
[CERT_BUF_LEN
];
213 struct blob_buf sigbuf
= {0};
217 len
= read_file(sigfile
, filebuf
, sizeof(filebuf
) - 1, 64);
220 perror("Unable to load signature file");
225 blob_buf_init(&sigbuf
, 0);
226 blob_put(&sigbuf
, CERT_ATTR_SIGNATURE
, filebuf
, len
);
227 ret
= write_file(certfile
, sigbuf
.head
, blob_raw_len(sigbuf
.head
), true);
228 blob_buf_free(&sigbuf
);
233 /* verify the signature of a single chain element */
234 static int cert_verify_blob(struct blob_attr
*cert
[CERT_ATTR_MAX
],
235 const char *pubkeyfile
, const char *pubkeydir
) {
237 char msgfname
[256], sigfname
[256];
239 char tmpdir
[] = "/tmp/ucert-XXXXXX";
241 if (mkdtemp(tmpdir
) == NULL
)
244 snprintf(msgfname
, sizeof(msgfname
) - 1, "%s/%s", tmpdir
, "payload");
245 snprintf(sigfname
, sizeof(sigfname
) - 1, "%s/%s", tmpdir
, "payload.sig");
247 for (i
= 0; i
< CERT_ATTR_MAX
; i
++) {
248 struct blob_attr
*v
= cert
[i
];
253 switch(cert_policy
[i
].type
) {
254 case BLOB_ATTR_BINARY
:
255 write_file(sigfname
, blob_data(v
), blob_len(v
), false);
257 case BLOB_ATTR_NESTED
:
258 write_file(msgfname
, blob_data(v
), blob_len(v
), false);
263 ret
= usign_v(msgfname
, pubkeyfile
, pubkeydir
, sigfname
, quiet
);
272 /* verify cert chain (and message) */
273 static int chain_verify(const char *msgfile
, const char *pubkeyfile
,
274 const char *pubkeydir
, struct list_head
*chain
) {
275 struct cert_object
*cobj
;
276 struct blob_attr
*containertb
[CERT_CT_ATTR_MAX
];
277 struct blob_attr
*payloadtb
[CERT_PL_ATTR_MAX
];
278 char tmpdir
[] = "/tmp/ucert-XXXXXX";
279 char chainedpubkey
[256] = {0};
280 char chainedfp
[17] = {0};
281 char extsigfile
[256] = {0};
286 if (mkdtemp(tmpdir
) == NULL
)
292 gettimeofday(&tv
, NULL
);
294 list_for_each_entry(cobj
, chain
, list
) {
295 /* blob has payload, verify that using signature */
296 if (cobj
->cert
[CERT_ATTR_PAYLOAD
]) {
301 ret
= cert_verify_blob(cobj
->cert
, chainedpubkey
[0]?chainedpubkey
:pubkeyfile
, pubkeydir
);
303 goto clean_and_return
;
305 blobmsg_parse(cert_cont_policy
,
306 ARRAY_SIZE(cert_cont_policy
),
308 blob_data(cobj
->cert
[CERT_ATTR_PAYLOAD
]),
309 blob_len(cobj
->cert
[CERT_ATTR_PAYLOAD
]));
310 if (!containertb
[CERT_CT_ATTR_PAYLOAD
]) {
312 DPRINTF("no ucert in signed payload\n");
313 goto clean_and_return
;
315 blobmsg_parse(cert_payload_policy
,
316 ARRAY_SIZE(cert_payload_policy
),
318 blobmsg_data(containertb
[CERT_CT_ATTR_PAYLOAD
]),
319 blobmsg_data_len(containertb
[CERT_CT_ATTR_PAYLOAD
]));
321 if (!payloadtb
[CERT_PL_ATTR_CERTTYPE
] ||
322 !payloadtb
[CERT_PL_ATTR_VALIDFROMTIME
] ||
323 !payloadtb
[CERT_PL_ATTR_EXPIRETIME
] ||
324 !payloadtb
[CERT_PL_ATTR_PUBKEY
]) {
326 DPRINTF("missing mandatory ucert attributes\n");
327 goto clean_and_return
;
329 certtype
= blobmsg_get_u32(payloadtb
[CERT_PL_ATTR_CERTTYPE
]);
330 validfrom
= blobmsg_get_u64(payloadtb
[CERT_PL_ATTR_VALIDFROMTIME
]);
331 expiresat
= blobmsg_get_u64(payloadtb
[CERT_PL_ATTR_EXPIRETIME
]);
333 if (certtype
!= CERTTYPE_AUTH
) {
335 DPRINTF("wrong certificate type\n");
336 goto clean_and_return
;
339 if (tv
.tv_sec
< validfrom
||
340 tv
.tv_sec
>= expiresat
) {
342 DPRINTF("certificate expired\n");
343 goto clean_and_return
;
346 snprintf(chainedpubkey
, sizeof(chainedpubkey
) - 1, "%s/%s", tmpdir
, "chained-pubkey");
347 write_file(chainedpubkey
,
348 blobmsg_data(payloadtb
[CERT_PL_ATTR_PUBKEY
]),
349 blobmsg_data_len(payloadtb
[CERT_PL_ATTR_PUBKEY
]),
352 if (usign_f_pubkey(chainedfp
, chainedpubkey
, quiet
)) {
353 DPRINTF("cannot get fingerprint for chained key\n");
355 goto clean_and_return
;
357 if (pubkeydir
&& _usign_key_is_revoked(chainedfp
, pubkeydir
)) {
358 DPRINTF("key %s has been revoked!\n", chainedfp
);
360 goto clean_and_return
;
363 /* blob doesn't have payload, verify message using signature */
365 snprintf(extsigfile
, sizeof(extsigfile
) - 1, "%s/%s", tmpdir
, "ext-sig");
366 write_file(extsigfile
,
367 blob_data(cobj
->cert
[CERT_ATTR_SIGNATURE
]),
368 blob_len(cobj
->cert
[CERT_ATTR_SIGNATURE
]),
370 checkmsg
= ret
= usign_v(msgfile
,
371 chainedpubkey
[0]?chainedpubkey
:pubkeyfile
,
372 pubkeydir
, extsigfile
, quiet
);
375 DPRINTF("stray trailing signature without anything to verify!\n");
382 DPRINTF("missing signature to verify message!\n");
385 if (chainedpubkey
[0])
386 unlink(chainedpubkey
);
388 return ret
| checkmsg
;
392 /* dump single chain element to console */
393 static void cert_dump_blob(struct blob_attr
*cert
[CERT_ATTR_MAX
]) {
397 for (i
= 0; i
< CERT_ATTR_MAX
; i
++) {
398 struct blob_attr
*v
= cert
[i
];
403 switch(cert_policy
[i
].type
) {
404 case BLOB_ATTR_BINARY
:
405 printf("signature:\n---\n%s---\n", (char *) blob_data(v
));
407 case BLOB_ATTR_NESTED
:
408 json
= blobmsg_format_json_indent(blob_data(v
), false, 0);
410 DPRINTF("cannot parse payload\n");
413 printf("payload:\n---\n%s\n---\n", json
);
420 /* dump certfile to console */
421 static int cert_dump(const char *certfile
) {
422 struct cert_object
*cobj
;
423 static LIST_HEAD(certchain
);
424 unsigned int count
= 0;
426 if (cert_load(certfile
, &certchain
)) {
427 DPRINTF("cannot parse cert\n");
431 list_for_each_entry(cobj
, &certchain
, list
) {
432 printf("=== CHAIN ELEMENT %02u ===\n", ++count
);
433 cert_dump_blob(cobj
->cert
);
439 /* issue an auth certificate for pubkey */
440 static int cert_issue(const char *certfile
, const char *pubkeyfile
, const char *seckeyfile
) {
441 struct blob_buf payloadbuf
= {0};
442 struct blob_buf certbuf
= {0};
444 ssize_t pklen
, siglen
;
449 char fname
[256], sfname
[256];
451 char tmpdir
[] = "/tmp/ucert-XXXXXX";
453 pklen
= read_file(pubkeyfile
, pkb
, sizeof(pkb
) - 1, 32);
456 perror("Unable to load public key file");
463 if (usign_f_pubkey(pkfp
, pubkeyfile
, quiet
))
466 gettimeofday(&tv
, NULL
);
468 if (mkdtemp(tmpdir
) == NULL
)
471 while (revoker
>= 0) {
472 blob_buf_init(&payloadbuf
, 0);
473 c
= blobmsg_open_table(&payloadbuf
, "ucert");
474 blobmsg_add_u32(&payloadbuf
, "certtype", revoker
?CERTTYPE_REVOKE
:CERTTYPE_AUTH
);
475 blobmsg_add_u64(&payloadbuf
, "validfrom", tv
.tv_sec
);
477 blobmsg_add_u64(&payloadbuf
, "expiresat", tv
.tv_sec
+ 60 * 60 * 24 * 365);
478 blobmsg_add_string(&payloadbuf
, "pubkey", pkb
);
480 blobmsg_add_string(&payloadbuf
, "fingerprint", pkfp
);
483 blobmsg_close_table(&payloadbuf
, c
);
485 snprintf(fname
, sizeof(fname
) - 1, "%s/%s", tmpdir
, revoker
?"revoker":"payload");
486 write_file(fname
, blob_data(payloadbuf
.head
), blob_len(payloadbuf
.head
), false);
488 snprintf(sfname
, sizeof(sfname
) - 1, "%s/%s", tmpdir
, revoker
?"revoker.sig":"payload.sig");
489 if (usign_s(fname
, seckeyfile
, sfname
, quiet
))
492 siglen
= read_file(sfname
, sigb
, sizeof(sigb
) - 1, 1);
495 perror("Unable to load signature file");
505 blob_buf_init(&certbuf
, 0);
506 blob_put(&certbuf
, CERT_ATTR_SIGNATURE
, sigb
, siglen
);
507 blob_put(&certbuf
, CERT_ATTR_PAYLOAD
, blob_data(payloadbuf
.head
), blob_len(payloadbuf
.head
));
508 snprintf(fname
, sizeof(fname
) - 1, "%s%s", certfile
, revoker
?".revoke":"");
509 write_file(fname
, certbuf
.head
, blob_raw_len(certbuf
.head
), true);
510 blob_buf_free(&certbuf
);
511 blob_buf_free(&payloadbuf
);
522 /* process revoker certificate */
523 static int cert_process_revoker(const char *certfile
, const char *pubkeydir
) {
524 static LIST_HEAD(certchain
);
525 struct cert_object
*cobj
;
526 struct blob_attr
*containertb
[CERT_CT_ATTR_MAX
];
527 struct blob_attr
*payloadtb
[CERT_PL_ATTR_MAX
];
531 enum certtype_id certtype
;
537 if (cert_load(certfile
, &certchain
)) {
538 DPRINTF("cannot parse cert\n");
542 gettimeofday(&tv
, NULL
);
544 list_for_each_entry(cobj
, &certchain
, list
) {
545 if (!cobj
->cert
[CERT_ATTR_PAYLOAD
])
548 /* blob has payload, verify that using signature */
549 ret
= cert_verify_blob(cobj
->cert
, NULL
, pubkeydir
);
553 blobmsg_parse(cert_cont_policy
,
554 ARRAY_SIZE(cert_cont_policy
),
556 blob_data(cobj
->cert
[CERT_ATTR_PAYLOAD
]),
557 blob_len(cobj
->cert
[CERT_ATTR_PAYLOAD
]));
558 if (!containertb
[CERT_CT_ATTR_PAYLOAD
]) {
559 DPRINTF("no ucert in signed payload\n");
563 blobmsg_parse(cert_payload_policy
,
564 ARRAY_SIZE(cert_payload_policy
),
566 blobmsg_data(containertb
[CERT_CT_ATTR_PAYLOAD
]),
567 blobmsg_data_len(containertb
[CERT_CT_ATTR_PAYLOAD
]));
569 if (!payloadtb
[CERT_PL_ATTR_CERTTYPE
] ||
570 !payloadtb
[CERT_PL_ATTR_VALIDFROMTIME
] ||
571 !payloadtb
[CERT_PL_ATTR_KEY_FINGERPRINT
]) {
572 DPRINTF("missing mandatory ucert attributes\n");
576 certtype
= blobmsg_get_u32(payloadtb
[CERT_PL_ATTR_CERTTYPE
]);
577 validfrom
= blobmsg_get_u64(payloadtb
[CERT_PL_ATTR_VALIDFROMTIME
]);
578 fingerprint
= blobmsg_get_string(payloadtb
[CERT_PL_ATTR_KEY_FINGERPRINT
]);
580 if (certtype
!= CERTTYPE_REVOKE
) {
581 DPRINTF("wrong certificate type\n");
585 if (tv
.tv_sec
< validfrom
) {
589 snprintf(rfname
, sizeof(rfname
)-1, "%s/%s", pubkeydir
, fingerprint
);
590 /* check if entry in pubkeydir exists */
591 if (stat(rfname
, &st
) == 0) {
592 if (_usign_key_is_revoked(fingerprint
, pubkeydir
)) {
593 DPRINTF("existing revoker deadlink for key %s\n", fingerprint
);
597 /* remove any other entry */
602 ret
= symlink(".revoked.", rfname
);
606 DPRINTF("created revoker deadlink for key %s\n", fingerprint
);
612 /* load and verify certfile (and message) */
613 static int cert_verify(const char *certfile
, const char *pubkeyfile
, const char *pubkeydir
, const char *msgfile
) {
614 static LIST_HEAD(certchain
);
616 if (cert_load(certfile
, &certchain
)) {
617 DPRINTF("cannot parse cert\n");
621 return chain_verify(msgfile
, pubkeyfile
, pubkeydir
, &certchain
);
625 static int usage(const char *cmd
)
627 #ifndef UCERT_STRIP_MESSAGES
629 "Usage: %s <command> <options>\n"
632 " -A: append signature (needs -c and -x)\n"
633 " -D: dump (needs -c)\n"
634 " -I: issue cert and revoker (needs -c and -p and -s)\n"
635 #endif /* UCERT_FULL */
636 " -R: process revoker certificate (needs -c and -P)\n"
637 " -V: verify (needs -c and -p|-P, may have -m)\n"
639 " -c <file>: certificate file\n"
640 " -m <file>: message file (verify only)\n"
641 " -p <file>: public key file\n"
642 " -P <path>: public key directory (verify only)\n"
643 " -q: quiet (do not print verification result, use return code only)\n"
645 " -s <file>: secret key file (issue only)\n"
646 " -x <file>: signature file (append only)\n"
647 #endif /* UCERT_FULL */
650 #endif /* UCERT_STRIP_MESSAGES */
654 /* parse command line options and call functions */
655 int main(int argc
, char *argv
[]) {
657 const char *msgfile
= NULL
;
658 const char *pubkeyfile
= NULL
;
659 const char *pubkeydir
= NULL
;
660 const char *certfile
= NULL
;
662 const char *sigfile
= NULL
;
663 const char *seckeyfile
= NULL
;
667 while ((ch
= getopt(argc
, argv
,
677 return usage(argv
[0]);
682 return usage(argv
[0]);
687 return usage(argv
[0]);
693 return usage(argv
[0]);
698 return usage(argv
[0]);
702 if (certfile
|| cmd
== CMD_NONE
)
703 return usage(argv
[0]);
707 if (msgfile
|| cmd
!= CMD_VERIFY
)
708 return usage(argv
[0]);
712 if (pubkeyfile
|| (cmd
!= CMD_VERIFY
&& cmd
!= CMD_ISSUE
) || cmd
== CMD_NONE
)
713 return usage(argv
[0]);
717 if (pubkeydir
|| (cmd
!= CMD_VERIFY
&& cmd
!= CMD_REVOKE
) || cmd
== CMD_NONE
)
718 return usage(argv
[0]);
723 return usage(argv
[0]);
728 if (seckeyfile
|| cmd
!= CMD_ISSUE
|| cmd
== CMD_NONE
)
729 return usage(argv
[0]);
733 if (sigfile
|| cmd
!= CMD_APPEND
|| cmd
== CMD_NONE
)
734 return usage(argv
[0]);
739 return usage(argv
[0]);
746 if (certfile
&& sigfile
)
747 return cert_append(certfile
, sigfile
);
749 return usage(argv
[0]);
752 return cert_dump(certfile
);
754 return usage(argv
[0]);
756 if (certfile
&& pubkeyfile
&& seckeyfile
)
757 return cert_issue(certfile
, pubkeyfile
, seckeyfile
);
759 return usage(argv
[0]);
762 if (certfile
&& pubkeydir
)
763 return cert_process_revoker(certfile
, pubkeydir
);
765 return usage(argv
[0]);
767 if (certfile
&& (pubkeyfile
|| pubkeydir
))
768 return cert_verify(certfile
, pubkeyfile
, pubkeydir
, msgfile
);
770 return usage(argv
[0]);
772 return usage(argv
[0]);
776 return usage(argv
[0]);