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]);