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};
255 if (mkdtemp(tmpdir
) == NULL
)
261 gettimeofday(&tv
, NULL
);
263 list_for_each_entry(cobj
, chain
, list
) {
264 /* blob has payload, verify that using signature */
265 if (cobj
->cert
[CERT_ATTR_PAYLOAD
]) {
270 ret
= cert_verify_blob(cobj
->cert
, chainedpubkey
[0]?chainedpubkey
:pubkeyfile
, pubkeydir
);
272 goto clean_and_return
;
274 blobmsg_parse(cert_cont_policy
,
275 ARRAY_SIZE(cert_cont_policy
),
277 blob_data(cobj
->cert
[CERT_ATTR_PAYLOAD
]),
278 blob_len(cobj
->cert
[CERT_ATTR_PAYLOAD
]));
279 if (!containertb
[CERT_CT_ATTR_PAYLOAD
]) {
282 fprintf(stderr
, "no ucert in signed payload\n");
283 goto clean_and_return
;
285 blobmsg_parse(cert_payload_policy
,
286 ARRAY_SIZE(cert_payload_policy
),
288 blobmsg_data(containertb
[CERT_CT_ATTR_PAYLOAD
]),
289 blobmsg_data_len(containertb
[CERT_CT_ATTR_PAYLOAD
]));
291 if (!payloadtb
[CERT_PL_ATTR_CERTTYPE
] ||
292 !payloadtb
[CERT_PL_ATTR_VALIDFROMTIME
] ||
293 !payloadtb
[CERT_PL_ATTR_EXPIRETIME
] ||
294 !payloadtb
[CERT_PL_ATTR_PUBKEY
]) {
297 fprintf(stderr
, "missing mandatory ucert attributes\n");
298 goto clean_and_return
;
300 certtype
= blobmsg_get_u32(payloadtb
[CERT_PL_ATTR_CERTTYPE
]);
301 validfrom
= blobmsg_get_u64(payloadtb
[CERT_PL_ATTR_VALIDFROMTIME
]);
302 expiresat
= blobmsg_get_u64(payloadtb
[CERT_PL_ATTR_EXPIRETIME
]);
304 if (certtype
!= CERTTYPE_AUTH
) {
307 fprintf(stderr
, "wrong certificate type\n");
308 goto clean_and_return
;
311 if (tv
.tv_sec
< validfrom
||
312 tv
.tv_sec
>= expiresat
) {
315 fprintf(stderr
, "certificate expired\n");
316 goto clean_and_return
;
319 snprintf(chainedpubkey
, sizeof(chainedpubkey
) - 1, "%s/%s", tmpdir
, "chained-pubkey");
320 write_file(chainedpubkey
,
321 blobmsg_data(payloadtb
[CERT_PL_ATTR_PUBKEY
]),
322 blobmsg_data_len(payloadtb
[CERT_PL_ATTR_PUBKEY
]),
325 if (usign_f_pubkey(chainedfp
, chainedpubkey
)) {
327 fprintf(stderr
, "cannot get fingerprint for chained key\n");
329 goto clean_and_return
;
331 if (pubkeydir
&& _usign_key_is_revoked(chainedfp
, pubkeydir
)) {
333 fprintf(stderr
, "key %s has been revoked!\n", chainedfp
);
335 goto clean_and_return
;
338 /* blob doesn't have payload, verify message using signature */
340 snprintf(extsigfile
, sizeof(extsigfile
) - 1, "%s/%s", tmpdir
, "ext-sig");
341 write_file(extsigfile
,
342 blob_data(cobj
->cert
[CERT_ATTR_SIGNATURE
]),
343 blob_len(cobj
->cert
[CERT_ATTR_SIGNATURE
]),
345 checkmsg
= ret
= usign_v(msgfile
,
346 chainedpubkey
[0]?chainedpubkey
:pubkeyfile
,
347 pubkeydir
, extsigfile
, quiet
);
351 fprintf(stderr
, "stray trailing signature without anything to verify!\n");
357 if (checkmsg
== -1 && !quiet
)
358 fprintf(stderr
, "missing signature to verify message!\n");
361 if (chainedpubkey
[0])
362 unlink(chainedpubkey
);
364 return ret
| checkmsg
;
367 /* dump single chain element to console */
368 static void cert_dump_blob(struct blob_attr
*cert
[CERT_ATTR_MAX
]) {
371 for (i
= 0; i
< CERT_ATTR_MAX
; i
++) {
372 struct blob_attr
*v
= cert
[i
];
377 switch(cert_policy
[i
].type
) {
378 case BLOB_ATTR_BINARY
:
379 fprintf(stdout
, "signature:\n---\n%s---\n", (char *) blob_data(v
));
381 case BLOB_ATTR_NESTED
:
382 fprintf(stdout
, "payload:\n---\n%s\n---\n", blobmsg_format_json_indent(blob_data(v
), false, 0));
388 /* dump certfile to console */
389 static int cert_dump(const char *certfile
) {
390 struct cert_object
*cobj
;
391 static LIST_HEAD(certchain
);
392 unsigned int count
= 0;
394 if (cert_load(certfile
, &certchain
)) {
396 fprintf(stderr
, "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
);
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 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
]) {
533 fprintf(stderr
, "no ucert in signed payload\n");
537 blobmsg_parse(cert_payload_policy
,
538 ARRAY_SIZE(cert_payload_policy
),
540 blobmsg_data(containertb
[CERT_CT_ATTR_PAYLOAD
]),
541 blobmsg_data_len(containertb
[CERT_CT_ATTR_PAYLOAD
]));
543 if (!payloadtb
[CERT_PL_ATTR_CERTTYPE
] ||
544 !payloadtb
[CERT_PL_ATTR_VALIDFROMTIME
] ||
545 !payloadtb
[CERT_PL_ATTR_KEY_FINGERPRINT
]) {
547 fprintf(stderr
, "missing mandatory ucert attributes\n");
551 certtype
= blobmsg_get_u32(payloadtb
[CERT_PL_ATTR_CERTTYPE
]);
552 validfrom
= blobmsg_get_u64(payloadtb
[CERT_PL_ATTR_VALIDFROMTIME
]);
553 fingerprint
= blobmsg_get_string(payloadtb
[CERT_PL_ATTR_KEY_FINGERPRINT
]);
555 if (certtype
!= CERTTYPE_REVOKE
) {
557 fprintf(stderr
, "wrong certificate type\n");
561 if (tv
.tv_sec
< validfrom
) {
565 snprintf(rfname
, sizeof(rfname
)-1, "%s/%s", pubkeydir
, fingerprint
);
566 /* check if entry in pubkeydir exists */
567 if (stat(rfname
, &st
) == 0) {
568 if (_usign_key_is_revoked(fingerprint
, pubkeydir
)) {
570 fprintf(stdout
, "existing revoker deadlink for key %s\n", fingerprint
);
574 /* remove any other entry */
579 ret
= symlink(".revoked.", rfname
);
584 fprintf(stdout
, "created revoker deadlink for key %s\n", fingerprint
);
590 /* load and verify certfile (and message) */
591 static int cert_verify(const char *certfile
, const char *pubkeyfile
, const char *pubkeydir
, const char *msgfile
) {
592 static LIST_HEAD(certchain
);
594 if (cert_load(certfile
, &certchain
)) {
596 fprintf(stderr
, "cannot parse cert\n");
600 return chain_verify(msgfile
, pubkeyfile
, pubkeydir
, &certchain
);
604 static int usage(const char *cmd
)
607 "Usage: %s <command> <options>\n"
609 " -A: append signature (needs -c and -x)\n"
610 " -D: dump (needs -c)\n"
611 " -I: issue cert and revoker (needs -c and -p and -s)\n"
612 " -R: process revoker certificate (needs -c and -P)\n"
613 " -V: verify (needs -c and -p|-P, may have -m)\n"
615 " -c <file>: certificate file\n"
616 " -m <file>: message file (verify only)\n"
617 " -p <file>: public key file\n"
618 " -P <path>: public key directory (verify only)\n"
619 " -q: quiet (do not print verification result, use return code only)\n"
620 " -s <file>: secret key file (issue only)\n"
621 " -x <file>: signature file\n"
627 /* parse command line options and call functions */
628 int main(int argc
, char *argv
[]) {
630 const char *msgfile
= NULL
;
631 const char *sigfile
= NULL
;
632 const char *pubkeyfile
= NULL
;
633 const char *pubkeydir
= NULL
;
634 const char *certfile
= NULL
;
635 const char *seckeyfile
= NULL
;
638 while ((ch
= getopt(argc
, argv
, "ADIRVc:m:p:P:qs:x:")) != -1) {
642 return usage(argv
[0]);
647 return usage(argv
[0]);
652 return usage(argv
[0]);
657 return usage(argv
[0]);
662 return usage(argv
[0]);
666 if (certfile
|| cmd
== CMD_NONE
)
667 return usage(argv
[0]);
671 if (msgfile
|| cmd
!= CMD_VERIFY
)
672 return usage(argv
[0]);
676 if (pubkeyfile
|| (cmd
!= CMD_VERIFY
&& cmd
!= CMD_ISSUE
) || cmd
== CMD_NONE
)
677 return usage(argv
[0]);
681 if (pubkeydir
|| (cmd
!= CMD_VERIFY
&& cmd
!= CMD_REVOKE
) || cmd
== CMD_NONE
)
682 return usage(argv
[0]);
687 return usage(argv
[0]);
691 if (seckeyfile
|| cmd
!= CMD_ISSUE
|| cmd
== CMD_NONE
)
692 return usage(argv
[0]);
696 if (sigfile
|| cmd
!= CMD_APPEND
|| cmd
== CMD_NONE
)
697 return usage(argv
[0]);
701 return usage(argv
[0]);
707 if (certfile
&& sigfile
)
708 return cert_append(certfile
, sigfile
);
710 return usage(argv
[0]);
713 return cert_dump(certfile
);
715 return usage(argv
[0]);
717 if (certfile
&& pubkeyfile
&& seckeyfile
)
718 return cert_issue(certfile
, pubkeyfile
, seckeyfile
);
720 return usage(argv
[0]);
722 if (certfile
&& pubkeydir
)
723 return cert_process_revoker(certfile
, pubkeydir
);
725 return usage(argv
[0]);
727 if (certfile
&& (pubkeyfile
|| pubkeydir
))
728 return cert_verify(certfile
, pubkeyfile
, pubkeydir
, msgfile
);
730 return usage(argv
[0]);
732 return usage(argv
[0]);
736 return usage(argv
[0]);