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, ...) \
54 fprintf(stderr, "%s(%d): " format, __func__, __LINE__, ## __VA_ARGS__); \
57 #define DPRINTF(format, ...) do { } while (0)
63 * | SIGNATURE | PAYLOAD |
64 * | |[ BLOBMSG CONTAINER ]|
65 * | |[[T,i,v,e,f,pubkey ]]|
73 static const struct blob_attr_info cert_policy
[CERT_ATTR_MAX
] = {
74 [CERT_ATTR_SIGNATURE
] = { .type
= BLOB_ATTR_BINARY
},
75 [CERT_ATTR_PAYLOAD
] = { .type
= BLOB_ATTR_NESTED
},
83 static const struct blobmsg_policy cert_cont_policy
[CERT_CT_ATTR_MAX
] = {
84 [CERT_CT_ATTR_PAYLOAD
] = { .name
= "ucert", .type
= BLOBMSG_TYPE_TABLE
},
87 enum cert_payload_attr
{
88 CERT_PL_ATTR_CERTTYPE
,
90 CERT_PL_ATTR_VALIDFROMTIME
,
91 CERT_PL_ATTR_EXPIRETIME
,
93 CERT_PL_ATTR_KEY_FINGERPRINT
,
103 static const struct blobmsg_policy cert_payload_policy
[CERT_PL_ATTR_MAX
] = {
104 [CERT_PL_ATTR_CERTTYPE
] = { .name
= "certtype", .type
= BLOBMSG_TYPE_INT32
},
105 [CERT_PL_ATTR_CERTID
] = { .name
= "certid", .type
= BLOBMSG_TYPE_INT32
},
106 [CERT_PL_ATTR_VALIDFROMTIME
] = { .name
= "validfrom", .type
= BLOBMSG_TYPE_INT64
},
107 [CERT_PL_ATTR_EXPIRETIME
] = { .name
= "expiresat", .type
= BLOBMSG_TYPE_INT64
},
108 [CERT_PL_ATTR_PUBKEY
] = { .name
= "pubkey", .type
= BLOBMSG_TYPE_STRING
},
109 [CERT_PL_ATTR_KEY_FINGERPRINT
] = { .name
= "fingerprint", .type
= BLOBMSG_TYPE_STRING
},
112 /* list to store certificate chain at runtime */
114 struct list_head list
;
115 struct blob_attr
*cert
[CERT_ATTR_MAX
];
118 /* write buffer to file */
119 static bool write_file(const char *filename
, void *buf
, size_t len
, bool append
) {
123 f
= fopen(filename
, append
?"a":"w");
127 outlen
= fwrite(buf
, 1, len
, f
);
129 return (outlen
== len
);
132 /* load certfile into list */
133 static int cert_load(const char *certfile
, struct list_head
*chain
) {
135 struct blob_attr
*certtb
[CERT_ATTR_MAX
];
136 struct blob_attr
*bufpt
;
137 struct cert_object
*cobj
;
138 char filebuf
[CERT_BUF_LEN
];
139 int ret
= 0, pret
= 0;
142 f
= fopen(certfile
, "r");
146 len
= fread(&filebuf
, 1, CERT_BUF_LEN
- 1, f
);
150 ret
= ferror(f
) || !feof(f
);
155 bufpt
= (struct blob_attr
*)filebuf
;
157 pret
= blob_parse_untrusted(bufpt
, len
, certtb
, cert_policy
, CERT_ATTR_MAX
);
159 /* no attributes found */
162 if (pos
+ blob_pad_len(bufpt
) > len
)
163 /* blob exceeds filebuffer */
166 pos
+= blob_pad_len(bufpt
);
168 if (!certtb
[CERT_ATTR_SIGNATURE
])
169 /* no signature -> drop */
172 cobj
= calloc(1, sizeof(*cobj
));
173 cobj
->cert
[CERT_ATTR_SIGNATURE
] = blob_memdup(certtb
[CERT_ATTR_SIGNATURE
]);
174 if (certtb
[CERT_ATTR_PAYLOAD
])
175 cobj
->cert
[CERT_ATTR_PAYLOAD
] = blob_memdup(certtb
[CERT_ATTR_PAYLOAD
]);
177 list_add_tail(&cobj
->list
, chain
);
179 /* repeat parsing while there is still enough remaining data in buffer */
180 } while(len
> pos
+ sizeof(struct blob_attr
) && (bufpt
= blob_next(bufpt
)));
186 /* append signature to certfile */
187 static int cert_append(const char *certfile
, const char *sigfile
) {
189 char filebuf
[CERT_BUF_LEN
];
190 struct blob_buf sigbuf
= {0};
194 fs
= fopen(sigfile
, "r");
198 len
= fread(&filebuf
, 1, CERT_BUF_LEN
- 1, fs
);
199 ret
= ferror(fs
) || !feof(fs
) || (len
< 64);
204 blob_buf_init(&sigbuf
, 0);
205 blob_put(&sigbuf
, CERT_ATTR_SIGNATURE
, filebuf
, len
);
206 ret
= write_file(certfile
, sigbuf
.head
, blob_raw_len(sigbuf
.head
), true);
207 blob_buf_free(&sigbuf
);
212 /* verify the signature of a single chain element */
213 static int cert_verify_blob(struct blob_attr
*cert
[CERT_ATTR_MAX
],
214 const char *pubkeyfile
, const char *pubkeydir
) {
216 char msgfname
[256], sigfname
[256];
218 char tmpdir
[] = "/tmp/ucert-XXXXXX";
220 if (mkdtemp(tmpdir
) == NULL
)
223 snprintf(msgfname
, sizeof(msgfname
) - 1, "%s/%s", tmpdir
, "payload");
224 snprintf(sigfname
, sizeof(sigfname
) - 1, "%s/%s", tmpdir
, "payload.sig");
226 for (i
= 0; i
< CERT_ATTR_MAX
; i
++) {
227 struct blob_attr
*v
= cert
[i
];
232 switch(cert_policy
[i
].type
) {
233 case BLOB_ATTR_BINARY
:
234 write_file(sigfname
, blob_data(v
), blob_len(v
), false);
236 case BLOB_ATTR_NESTED
:
237 write_file(msgfname
, blob_data(v
), blob_len(v
), false);
242 ret
= usign_v(msgfname
, pubkeyfile
, pubkeydir
, sigfname
, quiet
);
251 /* verify cert chain (and message) */
252 static int chain_verify(const char *msgfile
, const char *pubkeyfile
,
253 const char *pubkeydir
, struct list_head
*chain
) {
254 struct cert_object
*cobj
;
255 struct blob_attr
*containertb
[CERT_CT_ATTR_MAX
];
256 struct blob_attr
*payloadtb
[CERT_PL_ATTR_MAX
];
257 char tmpdir
[] = "/tmp/ucert-XXXXXX";
258 char chainedpubkey
[256] = {0};
259 char chainedfp
[17] = {0};
260 char extsigfile
[256] = {0};
265 if (mkdtemp(tmpdir
) == NULL
)
271 gettimeofday(&tv
, NULL
);
273 list_for_each_entry(cobj
, chain
, list
) {
274 /* blob has payload, verify that using signature */
275 if (cobj
->cert
[CERT_ATTR_PAYLOAD
]) {
280 ret
= cert_verify_blob(cobj
->cert
, chainedpubkey
[0]?chainedpubkey
:pubkeyfile
, pubkeydir
);
282 goto clean_and_return
;
284 blobmsg_parse(cert_cont_policy
,
285 ARRAY_SIZE(cert_cont_policy
),
287 blob_data(cobj
->cert
[CERT_ATTR_PAYLOAD
]),
288 blob_len(cobj
->cert
[CERT_ATTR_PAYLOAD
]));
289 if (!containertb
[CERT_CT_ATTR_PAYLOAD
]) {
291 DPRINTF("no ucert in signed payload\n");
292 goto clean_and_return
;
294 blobmsg_parse(cert_payload_policy
,
295 ARRAY_SIZE(cert_payload_policy
),
297 blobmsg_data(containertb
[CERT_CT_ATTR_PAYLOAD
]),
298 blobmsg_data_len(containertb
[CERT_CT_ATTR_PAYLOAD
]));
300 if (!payloadtb
[CERT_PL_ATTR_CERTTYPE
] ||
301 !payloadtb
[CERT_PL_ATTR_VALIDFROMTIME
] ||
302 !payloadtb
[CERT_PL_ATTR_EXPIRETIME
] ||
303 !payloadtb
[CERT_PL_ATTR_PUBKEY
]) {
305 DPRINTF("missing mandatory ucert attributes\n");
306 goto clean_and_return
;
308 certtype
= blobmsg_get_u32(payloadtb
[CERT_PL_ATTR_CERTTYPE
]);
309 validfrom
= blobmsg_get_u64(payloadtb
[CERT_PL_ATTR_VALIDFROMTIME
]);
310 expiresat
= blobmsg_get_u64(payloadtb
[CERT_PL_ATTR_EXPIRETIME
]);
312 if (certtype
!= CERTTYPE_AUTH
) {
314 DPRINTF("wrong certificate type\n");
315 goto clean_and_return
;
318 if (tv
.tv_sec
< validfrom
||
319 tv
.tv_sec
>= expiresat
) {
321 DPRINTF("certificate expired\n");
322 goto clean_and_return
;
325 snprintf(chainedpubkey
, sizeof(chainedpubkey
) - 1, "%s/%s", tmpdir
, "chained-pubkey");
326 write_file(chainedpubkey
,
327 blobmsg_data(payloadtb
[CERT_PL_ATTR_PUBKEY
]),
328 blobmsg_data_len(payloadtb
[CERT_PL_ATTR_PUBKEY
]),
331 if (usign_f_pubkey(chainedfp
, chainedpubkey
)) {
332 DPRINTF("cannot get fingerprint for chained key\n");
334 goto clean_and_return
;
336 if (pubkeydir
&& _usign_key_is_revoked(chainedfp
, pubkeydir
)) {
337 DPRINTF("key %s has been revoked!\n", chainedfp
);
339 goto clean_and_return
;
342 /* blob doesn't have payload, verify message using signature */
344 snprintf(extsigfile
, sizeof(extsigfile
) - 1, "%s/%s", tmpdir
, "ext-sig");
345 write_file(extsigfile
,
346 blob_data(cobj
->cert
[CERT_ATTR_SIGNATURE
]),
347 blob_len(cobj
->cert
[CERT_ATTR_SIGNATURE
]),
349 checkmsg
= ret
= usign_v(msgfile
,
350 chainedpubkey
[0]?chainedpubkey
:pubkeyfile
,
351 pubkeydir
, extsigfile
, quiet
);
354 DPRINTF("stray trailing signature without anything to verify!\n");
361 DPRINTF("missing signature to verify message!\n");
364 if (chainedpubkey
[0])
365 unlink(chainedpubkey
);
367 return ret
| checkmsg
;
371 /* dump single chain element to console */
372 static void cert_dump_blob(struct blob_attr
*cert
[CERT_ATTR_MAX
]) {
376 for (i
= 0; i
< CERT_ATTR_MAX
; i
++) {
377 struct blob_attr
*v
= cert
[i
];
382 switch(cert_policy
[i
].type
) {
383 case BLOB_ATTR_BINARY
:
384 printf("signature:\n---\n%s---\n", (char *) blob_data(v
));
386 case BLOB_ATTR_NESTED
:
387 json
= blobmsg_format_json_indent(blob_data(v
), false, 0);
389 DPRINTF("cannot parse payload\n");
392 printf("payload:\n---\n%s\n---\n", json
);
399 /* dump certfile to console */
400 static int cert_dump(const char *certfile
) {
401 struct cert_object
*cobj
;
402 static LIST_HEAD(certchain
);
403 unsigned int count
= 0;
405 if (cert_load(certfile
, &certchain
)) {
406 DPRINTF("cannot parse cert\n");
410 list_for_each_entry(cobj
, &certchain
, list
) {
411 printf("=== CHAIN ELEMENT %02u ===\n", ++count
);
412 cert_dump_blob(cobj
->cert
);
418 /* issue an auth certificate for pubkey */
419 static int cert_issue(const char *certfile
, const char *pubkeyfile
, const char *seckeyfile
) {
420 struct blob_buf payloadbuf
= {0};
421 struct blob_buf certbuf
= {0};
429 char fname
[256], sfname
[256];
431 char tmpdir
[] = "/tmp/ucert-XXXXXX";
433 pkf
= fopen(pubkeyfile
, "r");
437 pklen
= fread(pkb
, 1, 512, pkf
);
445 if (usign_f_pubkey(pkfp
, pubkeyfile
))
448 gettimeofday(&tv
, NULL
);
450 if (mkdtemp(tmpdir
) == NULL
)
453 while (revoker
>= 0) {
454 blob_buf_init(&payloadbuf
, 0);
455 c
= blobmsg_open_table(&payloadbuf
, "ucert");
456 blobmsg_add_u32(&payloadbuf
, "certtype", revoker
?CERTTYPE_REVOKE
:CERTTYPE_AUTH
);
457 blobmsg_add_u64(&payloadbuf
, "validfrom", tv
.tv_sec
);
459 blobmsg_add_u64(&payloadbuf
, "expiresat", tv
.tv_sec
+ 60 * 60 * 24 * 365);
460 blobmsg_add_string(&payloadbuf
, "pubkey", pkb
);
462 blobmsg_add_string(&payloadbuf
, "fingerprint", pkfp
);
465 blobmsg_close_table(&payloadbuf
, c
);
467 snprintf(fname
, sizeof(fname
) - 1, "%s/%s", tmpdir
, revoker
?"revoker":"payload");
468 write_file(fname
, blob_data(payloadbuf
.head
), blob_len(payloadbuf
.head
), false);
470 snprintf(sfname
, sizeof(sfname
) - 1, "%s/%s", tmpdir
, revoker
?"revoker.sig":"payload.sig");
471 if (usign_s(fname
, seckeyfile
, sfname
, quiet
))
474 sigf
= fopen(sfname
, "r");
478 siglen
= fread(sigb
, 1, 1024, sigf
);
488 blob_buf_init(&certbuf
, 0);
489 blob_put(&certbuf
, CERT_ATTR_SIGNATURE
, sigb
, siglen
);
490 blob_put(&certbuf
, CERT_ATTR_PAYLOAD
, blob_data(payloadbuf
.head
), blob_len(payloadbuf
.head
));
491 snprintf(fname
, sizeof(fname
) - 1, "%s%s", certfile
, revoker
?".revoke":"");
492 write_file(fname
, certbuf
.head
, blob_raw_len(certbuf
.head
), true);
493 blob_buf_free(&certbuf
);
494 blob_buf_free(&payloadbuf
);
505 /* process revoker certificate */
506 static int cert_process_revoker(const char *certfile
, const char *pubkeydir
) {
507 static LIST_HEAD(certchain
);
508 struct cert_object
*cobj
;
509 struct blob_attr
*containertb
[CERT_CT_ATTR_MAX
];
510 struct blob_attr
*payloadtb
[CERT_PL_ATTR_MAX
];
514 enum certtype_id certtype
;
520 if (cert_load(certfile
, &certchain
)) {
521 DPRINTF("cannot parse cert\n");
525 gettimeofday(&tv
, NULL
);
527 list_for_each_entry(cobj
, &certchain
, list
) {
528 if (!cobj
->cert
[CERT_ATTR_PAYLOAD
])
531 /* blob has payload, verify that using signature */
532 ret
= cert_verify_blob(cobj
->cert
, NULL
, pubkeydir
);
536 blobmsg_parse(cert_cont_policy
,
537 ARRAY_SIZE(cert_cont_policy
),
539 blob_data(cobj
->cert
[CERT_ATTR_PAYLOAD
]),
540 blob_len(cobj
->cert
[CERT_ATTR_PAYLOAD
]));
541 if (!containertb
[CERT_CT_ATTR_PAYLOAD
]) {
542 DPRINTF("no ucert in signed payload\n");
546 blobmsg_parse(cert_payload_policy
,
547 ARRAY_SIZE(cert_payload_policy
),
549 blobmsg_data(containertb
[CERT_CT_ATTR_PAYLOAD
]),
550 blobmsg_data_len(containertb
[CERT_CT_ATTR_PAYLOAD
]));
552 if (!payloadtb
[CERT_PL_ATTR_CERTTYPE
] ||
553 !payloadtb
[CERT_PL_ATTR_VALIDFROMTIME
] ||
554 !payloadtb
[CERT_PL_ATTR_KEY_FINGERPRINT
]) {
555 DPRINTF("missing mandatory ucert attributes\n");
559 certtype
= blobmsg_get_u32(payloadtb
[CERT_PL_ATTR_CERTTYPE
]);
560 validfrom
= blobmsg_get_u64(payloadtb
[CERT_PL_ATTR_VALIDFROMTIME
]);
561 fingerprint
= blobmsg_get_string(payloadtb
[CERT_PL_ATTR_KEY_FINGERPRINT
]);
563 if (certtype
!= CERTTYPE_REVOKE
) {
564 DPRINTF("wrong certificate type\n");
568 if (tv
.tv_sec
< validfrom
) {
572 snprintf(rfname
, sizeof(rfname
)-1, "%s/%s", pubkeydir
, fingerprint
);
573 /* check if entry in pubkeydir exists */
574 if (stat(rfname
, &st
) == 0) {
575 if (_usign_key_is_revoked(fingerprint
, pubkeydir
)) {
576 DPRINTF("existing revoker deadlink for key %s\n", fingerprint
);
580 /* remove any other entry */
585 ret
= symlink(".revoked.", rfname
);
589 DPRINTF("created revoker deadlink for key %s\n", fingerprint
);
595 /* load and verify certfile (and message) */
596 static int cert_verify(const char *certfile
, const char *pubkeyfile
, const char *pubkeydir
, const char *msgfile
) {
597 static LIST_HEAD(certchain
);
599 if (cert_load(certfile
, &certchain
)) {
600 DPRINTF("cannot parse cert\n");
604 return chain_verify(msgfile
, pubkeyfile
, pubkeydir
, &certchain
);
608 static int usage(const char *cmd
)
610 #ifndef UCERT_STRIP_MESSAGES
612 "Usage: %s <command> <options>\n"
615 " -A: append signature (needs -c and -x)\n"
616 " -D: dump (needs -c)\n"
617 " -I: issue cert and revoker (needs -c and -p and -s)\n"
618 #endif /* UCERT_FULL */
619 " -R: process revoker certificate (needs -c and -P)\n"
620 " -V: verify (needs -c and -p|-P, may have -m)\n"
622 " -c <file>: certificate file\n"
623 " -m <file>: message file (verify only)\n"
624 " -p <file>: public key file\n"
625 " -P <path>: public key directory (verify only)\n"
626 " -q: quiet (do not print verification result, use return code only)\n"
628 " -s <file>: secret key file (issue only)\n"
629 " -x <file>: signature file (append only)\n"
630 #endif /* UCERT_FULL */
633 #endif /* UCERT_STRIP_MESSAGES */
637 /* parse command line options and call functions */
638 int main(int argc
, char *argv
[]) {
640 const char *msgfile
= NULL
;
641 const char *pubkeyfile
= NULL
;
642 const char *pubkeydir
= NULL
;
643 const char *certfile
= NULL
;
645 const char *sigfile
= NULL
;
646 const char *seckeyfile
= NULL
;
650 while ((ch
= getopt(argc
, argv
,
660 return usage(argv
[0]);
665 return usage(argv
[0]);
670 return usage(argv
[0]);
676 return usage(argv
[0]);
681 return usage(argv
[0]);
685 if (certfile
|| cmd
== CMD_NONE
)
686 return usage(argv
[0]);
690 if (msgfile
|| cmd
!= CMD_VERIFY
)
691 return usage(argv
[0]);
695 if (pubkeyfile
|| (cmd
!= CMD_VERIFY
&& cmd
!= CMD_ISSUE
) || cmd
== CMD_NONE
)
696 return usage(argv
[0]);
700 if (pubkeydir
|| (cmd
!= CMD_VERIFY
&& cmd
!= CMD_REVOKE
) || cmd
== CMD_NONE
)
701 return usage(argv
[0]);
706 return usage(argv
[0]);
711 if (seckeyfile
|| cmd
!= CMD_ISSUE
|| cmd
== CMD_NONE
)
712 return usage(argv
[0]);
716 if (sigfile
|| cmd
!= CMD_APPEND
|| cmd
== CMD_NONE
)
717 return usage(argv
[0]);
722 return usage(argv
[0]);
729 if (certfile
&& sigfile
)
730 return cert_append(certfile
, sigfile
);
732 return usage(argv
[0]);
735 return cert_dump(certfile
);
737 return usage(argv
[0]);
739 if (certfile
&& pubkeyfile
&& seckeyfile
)
740 return cert_issue(certfile
, pubkeyfile
, seckeyfile
);
742 return usage(argv
[0]);
745 if (certfile
&& pubkeydir
)
746 return cert_process_revoker(certfile
, pubkeydir
);
748 return usage(argv
[0]);
750 if (certfile
&& (pubkeyfile
|| pubkeydir
))
751 return cert_verify(certfile
, pubkeyfile
, pubkeydir
, msgfile
);
753 return usage(argv
[0]);
755 return usage(argv
[0]);
759 return usage(argv
[0]);