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 cobj
= calloc(1, sizeof(*cobj
));
160 memcpy(cobj
->cert
, &certtb
, sizeof(certtb
));
161 list_add_tail(&cobj
->list
, chain
);
163 bufpt
= blob_next(bufpt
);
164 /* repeat parsing while there is still enough remaining data in buffer */
165 } while(len
> pos
+ sizeof(struct blob_attr
));
170 /* append signature to certfile */
171 static int cert_append(const char *certfile
, const char *sigfile
) {
173 char filebuf
[CERT_BUF_LEN
];
174 struct blob_buf sigbuf
;
178 fs
= fopen(sigfile
, "r");
182 len
= fread(&filebuf
, 1, CERT_BUF_LEN
- 1, fs
);
183 ret
= ferror(fs
) || !feof(fs
) || (len
< 64);
188 blob_buf_init(&sigbuf
, 0);
189 blob_put(&sigbuf
, CERT_ATTR_SIGNATURE
, filebuf
, len
);
190 ret
= write_file(certfile
, sigbuf
.head
, blob_raw_len(sigbuf
.head
), true);
191 blob_buf_free(&sigbuf
);
195 /* verify the signature of a single chain element */
196 static int cert_verify_blob(struct blob_attr
*cert
[CERT_ATTR_MAX
],
197 const char *pubkeyfile
, const char *pubkeydir
) {
199 char msgfname
[256], sigfname
[256];
201 char tmpdir
[] = "/tmp/ucert-XXXXXX";
203 if (mkdtemp(tmpdir
) == NULL
)
206 snprintf(msgfname
, sizeof(msgfname
) - 1, "%s/%s", tmpdir
, "payload");
207 snprintf(sigfname
, sizeof(sigfname
) - 1, "%s/%s", tmpdir
, "payload.sig");
209 for (i
= 0; i
< CERT_ATTR_MAX
; i
++) {
210 struct blob_attr
*v
= cert
[i
];
215 switch(cert_policy
[i
].type
) {
216 case BLOB_ATTR_BINARY
:
217 write_file(sigfname
, blob_data(v
), blob_len(v
), false);
219 case BLOB_ATTR_NESTED
:
220 write_file(msgfname
, blob_data(v
), blob_len(v
), false);
225 ret
= usign_v(msgfname
, pubkeyfile
, pubkeydir
, sigfname
, quiet
);
234 /* verify cert chain (and message) */
235 static int chain_verify(const char *msgfile
, const char *pubkeyfile
,
236 const char *pubkeydir
, struct list_head
*chain
) {
237 struct cert_object
*cobj
;
238 struct blob_attr
*containertb
[CERT_CT_ATTR_MAX
];
239 struct blob_attr
*payloadtb
[CERT_PL_ATTR_MAX
];
240 char tmpdir
[] = "/tmp/ucert-XXXXXX";
241 char chainedpubkey
[256] = {0};
242 char chainedfp
[17] = {0};
243 char extsigfile
[256] = {0};
247 if (mkdtemp(tmpdir
) == NULL
)
253 list_for_each_entry(cobj
, chain
, list
) {
254 /* blob has payload, verify that using signature */
255 if (cobj
->cert
[CERT_ATTR_PAYLOAD
]) {
261 ret
= cert_verify_blob(cobj
->cert
, chainedpubkey
[0]?chainedpubkey
:pubkeyfile
, pubkeydir
);
263 goto clean_and_return
;
265 blobmsg_parse(cert_cont_policy
,
266 ARRAY_SIZE(cert_cont_policy
),
268 blob_data(cobj
->cert
[CERT_ATTR_PAYLOAD
]),
269 blob_len(cobj
->cert
[CERT_ATTR_PAYLOAD
]));
270 if (!containertb
[CERT_CT_ATTR_PAYLOAD
]) {
272 fprintf(stderr
, "no ucert in signed payload\n");
273 goto clean_and_return
;
275 blobmsg_parse(cert_payload_policy
,
276 ARRAY_SIZE(cert_payload_policy
),
278 blobmsg_data(containertb
[CERT_CT_ATTR_PAYLOAD
]),
279 blobmsg_data_len(containertb
[CERT_CT_ATTR_PAYLOAD
]));
281 if (!payloadtb
[CERT_PL_ATTR_CERTTYPE
] ||
282 !payloadtb
[CERT_PL_ATTR_VALIDFROMTIME
] ||
283 !payloadtb
[CERT_PL_ATTR_EXPIRETIME
] ||
284 !payloadtb
[CERT_PL_ATTR_PUBKEY
]) {
286 fprintf(stderr
, "missing mandatory ucert attributes\n");
287 goto clean_and_return
;
289 certtype
= blobmsg_get_u32(payloadtb
[CERT_PL_ATTR_CERTTYPE
]);
290 validfrom
= blobmsg_get_u64(payloadtb
[CERT_PL_ATTR_VALIDFROMTIME
]);
291 expiresat
= blobmsg_get_u64(payloadtb
[CERT_PL_ATTR_EXPIRETIME
]);
293 if (certtype
!= CERTTYPE_AUTH
) {
295 fprintf(stderr
, "wrong certificate type\n");
296 goto clean_and_return
;
299 gettimeofday(&tv
, NULL
);
300 if (tv
.tv_sec
< validfrom
||
301 tv
.tv_sec
>= expiresat
) {
303 fprintf(stderr
, "certificate expired\n");
304 goto clean_and_return
;
307 snprintf(chainedpubkey
, sizeof(chainedpubkey
) - 1, "%s/%s", tmpdir
, "chained-pubkey");
308 write_file(chainedpubkey
,
309 blobmsg_data(payloadtb
[CERT_PL_ATTR_PUBKEY
]),
310 blobmsg_data_len(payloadtb
[CERT_PL_ATTR_PUBKEY
]),
313 if (usign_f_pubkey(chainedfp
, chainedpubkey
)) {
315 fprintf(stderr
, "cannot get fingerprint for chained key\n");
317 goto clean_and_return
;
319 if (pubkeydir
&& _usign_key_is_revoked(chainedfp
, pubkeydir
)) {
321 fprintf(stderr
, "key %s has been revoked!\n", chainedfp
);
323 goto clean_and_return
;
326 /* blob doesn't have payload, verify message using signature */
328 snprintf(extsigfile
, sizeof(extsigfile
) - 1, "%s/%s", tmpdir
, "ext-sig");
329 write_file(extsigfile
,
330 blob_data(cobj
->cert
[CERT_ATTR_SIGNATURE
]),
331 blob_len(cobj
->cert
[CERT_ATTR_SIGNATURE
]),
333 checkmsg
= ret
= usign_v(msgfile
,
334 chainedpubkey
[0]?chainedpubkey
:pubkeyfile
,
335 pubkeydir
, extsigfile
, quiet
);
338 fprintf(stderr
, "stray trailing signature without anything to verify!\n");
345 fprintf(stderr
, "missing signature to verify message!\n");
348 if (chainedpubkey
[0])
349 unlink(chainedpubkey
);
351 return ret
| checkmsg
;
354 /* dump single chain element to console */
355 static void cert_dump_blob(struct blob_attr
*cert
[CERT_ATTR_MAX
]) {
358 for (i
= 0; i
< CERT_ATTR_MAX
; i
++) {
359 struct blob_attr
*v
= cert
[i
];
364 switch(cert_policy
[i
].type
) {
365 case BLOB_ATTR_BINARY
:
366 fprintf(stdout
, "signature:\n---\n%s---\n", (char *) blob_data(v
));
368 case BLOB_ATTR_NESTED
:
369 fprintf(stdout
, "payload:\n---\n%s\n---\n", blobmsg_format_json_indent(blob_data(v
), false, 0));
375 /* dump certfile to console */
376 static int cert_dump(const char *certfile
) {
377 struct cert_object
*cobj
;
378 static LIST_HEAD(certchain
);
379 unsigned int count
= 0;
381 if (cert_load(certfile
, &certchain
)) {
382 fprintf(stderr
, "cannot parse cert\n");
386 list_for_each_entry(cobj
, &certchain
, list
) {
387 fprintf(stderr
, "=== CHAIN ELEMENT %02u ===\n", ++count
);
388 cert_dump_blob(cobj
->cert
);
389 fprintf(stderr
, "========================\n");
395 /* issue an auth certificate for pubkey */
396 static int cert_issue(const char *certfile
, const char *pubkeyfile
, const char *seckeyfile
) {
397 struct blob_buf certbuf
;
398 struct blob_buf payloadbuf
;
407 char fname
[256], sfname
[256];
409 char tmpdir
[] = "/tmp/ucert-XXXXXX";
411 if (stat(certfile
, &st
) == 0) {
412 fprintf(stderr
, "certfile %s exists, won't overwrite.\n", certfile
);
416 pkf
= fopen(pubkeyfile
, "r");
420 pklen
= fread(pkb
, 1, 512, pkf
);
428 if (usign_f_pubkey(pkfp
, pubkeyfile
))
431 gettimeofday(&tv
, NULL
);
433 if (mkdtemp(tmpdir
) == NULL
)
436 while (revoker
>= 0) {
437 blob_buf_init(&payloadbuf
, 0);
438 c
= blobmsg_open_table(&payloadbuf
, "ucert");
439 blobmsg_add_u32(&payloadbuf
, "certtype", revoker
?CERTTYPE_REVOKE
:CERTTYPE_AUTH
);
440 blobmsg_add_u64(&payloadbuf
, "validfrom", tv
.tv_sec
);
442 blobmsg_add_u64(&payloadbuf
, "expiresat", tv
.tv_sec
+ 60 * 60 * 24 * 365);
443 blobmsg_add_string(&payloadbuf
, "pubkey", pkb
);
445 blobmsg_add_string(&payloadbuf
, "fingerprint", pkfp
);
448 blobmsg_close_table(&payloadbuf
, c
);
450 snprintf(fname
, sizeof(fname
) - 1, "%s/%s", tmpdir
, revoker
?"revoker":"payload");
451 write_file(fname
, blob_data(payloadbuf
.head
), blob_len(payloadbuf
.head
), false);
453 snprintf(sfname
, sizeof(sfname
) - 1, "%s/%s", tmpdir
, revoker
?"revoker.sig":"payload.sig");
454 if (usign_s(fname
, seckeyfile
, sfname
, quiet
))
457 sigf
= fopen(sfname
, "r");
461 siglen
= fread(sigb
, 1, 1024, sigf
);
471 blob_buf_init(&certbuf
, 0);
472 blob_put(&certbuf
, CERT_ATTR_SIGNATURE
, sigb
, siglen
);
473 blob_put(&certbuf
, CERT_ATTR_PAYLOAD
, blob_data(payloadbuf
.head
), blob_len(payloadbuf
.head
));
474 snprintf(fname
, sizeof(fname
) - 1, "%s%s", certfile
, revoker
?".revoke":"");
475 write_file(fname
, certbuf
.head
, blob_raw_len(certbuf
.head
), false);
476 blob_buf_free(&certbuf
);
477 blob_buf_free(&payloadbuf
);
487 /* process revoker certificate */
488 static int cert_process_revoker(const char *certfile
, const char *pubkeydir
) {
489 static LIST_HEAD(certchain
);
490 struct cert_object
*cobj
;
491 struct blob_attr
*containertb
[CERT_CT_ATTR_MAX
];
492 struct blob_attr
*payloadtb
[CERT_PL_ATTR_MAX
];
502 if (cert_load(certfile
, &certchain
)) {
503 fprintf(stderr
, "cannot parse cert\n");
507 list_for_each_entry(cobj
, &certchain
, list
) {
508 /* blob has payload, verify that using signature */
509 if (!cobj
->cert
[CERT_ATTR_PAYLOAD
])
511 ret
= cert_verify_blob(cobj
->cert
, NULL
, pubkeydir
);
515 blobmsg_parse(cert_cont_policy
,
516 ARRAY_SIZE(cert_cont_policy
),
518 blob_data(cobj
->cert
[CERT_ATTR_PAYLOAD
]),
519 blob_len(cobj
->cert
[CERT_ATTR_PAYLOAD
]));
520 if (!containertb
[CERT_CT_ATTR_PAYLOAD
]) {
521 fprintf(stderr
, "no ucert in signed payload\n");
525 blobmsg_parse(cert_payload_policy
,
526 ARRAY_SIZE(cert_payload_policy
),
528 blobmsg_data(containertb
[CERT_CT_ATTR_PAYLOAD
]),
529 blobmsg_data_len(containertb
[CERT_CT_ATTR_PAYLOAD
]));
531 if (!payloadtb
[CERT_PL_ATTR_CERTTYPE
] ||
532 !payloadtb
[CERT_PL_ATTR_VALIDFROMTIME
] ||
533 !payloadtb
[CERT_PL_ATTR_KEY_FINGERPRINT
]) {
534 fprintf(stderr
, "missing mandatory ucert attributes\n");
538 certtype
= blobmsg_get_u32(payloadtb
[CERT_PL_ATTR_CERTTYPE
]);
539 validfrom
= blobmsg_get_u64(payloadtb
[CERT_PL_ATTR_VALIDFROMTIME
]);
540 fingerprint
= blobmsg_get_string(payloadtb
[CERT_PL_ATTR_KEY_FINGERPRINT
]);
542 if (certtype
!= CERTTYPE_REVOKE
) {
543 fprintf(stderr
, "wrong certificate type\n");
547 gettimeofday(&tv
, NULL
);
548 if (tv
.tv_sec
< validfrom
) {
552 snprintf(rfname
, sizeof(rfname
)-1, "%s/%s", pubkeydir
, fingerprint
);
553 /* check if entry in pubkeydir exists */
554 if (stat(rfname
, &st
) == 0) {
555 if (_usign_key_is_revoked(fingerprint
, pubkeydir
)) {
557 fprintf(stdout
, "existing revoker deadlink for key %s\n", fingerprint
);
561 /* remove any other entry */
566 ret
= symlink(".revoked.", rfname
);
571 fprintf(stdout
, "created revoker deadlink for key %s\n", fingerprint
);
577 /* load and verify certfile (and message) */
578 static int cert_verify(const char *certfile
, const char *pubkeyfile
, const char *pubkeydir
, const char *msgfile
) {
579 static LIST_HEAD(certchain
);
581 if (cert_load(certfile
, &certchain
)) {
582 fprintf(stderr
, "cannot parse cert\n");
586 return chain_verify(msgfile
, pubkeyfile
, pubkeydir
, &certchain
);
590 static int usage(const char *cmd
)
593 "Usage: %s <command> <options>\n"
595 " -A: append signature (needs -c and -x)\n"
596 " -D: dump (needs -c)\n"
597 " -I: issue cert and revoker (needs -c and -p and -s)\n"
598 " -R: process revoker certificate (needs -c and -P)\n"
599 " -V: verify (needs -c and -p|-P, may have -m)\n"
601 " -c <file>: certificate file\n"
602 " -m <file>: message file (verify only)\n"
603 " -p <file>: public key file\n"
604 " -P <path>: public key directory (verify only)\n"
605 " -q: quiet (do not print verification result, use return code only)\n"
606 " -s <file>: secret key file (issue only)\n"
607 " -x <file>: signature file\n"
613 /* parse command line options and call functions */
614 int main(int argc
, char *argv
[]) {
616 const char *msgfile
= NULL
;
617 const char *sigfile
= NULL
;
618 const char *pubkeyfile
= NULL
;
619 const char *pubkeydir
= NULL
;
620 const char *certfile
= NULL
;
621 const char *seckeyfile
= NULL
;
624 while ((ch
= getopt(argc
, argv
, "ADIRVc:m:p:P:qs:x:")) != -1) {
628 return usage(argv
[0]);
633 return usage(argv
[0]);
638 return usage(argv
[0]);
643 return usage(argv
[0]);
648 return usage(argv
[0]);
652 if (certfile
|| cmd
== CMD_NONE
)
653 return usage(argv
[0]);
657 if (msgfile
|| cmd
!= CMD_VERIFY
)
658 return usage(argv
[0]);
662 if (pubkeyfile
|| (cmd
!= CMD_VERIFY
&& cmd
!= CMD_ISSUE
) || cmd
== CMD_NONE
)
663 return usage(argv
[0]);
667 if (pubkeydir
|| (cmd
!= CMD_VERIFY
&& cmd
!= CMD_REVOKE
) || cmd
== CMD_NONE
)
668 return usage(argv
[0]);
672 if (quiet
|| cmd
== CMD_NONE
)
673 return usage(argv
[0]);
677 if (seckeyfile
|| cmd
!= CMD_ISSUE
|| cmd
== CMD_NONE
)
678 return usage(argv
[0]);
682 if (sigfile
|| cmd
!= CMD_APPEND
|| cmd
== CMD_NONE
)
683 return usage(argv
[0]);
687 return usage(argv
[0]);
693 if (certfile
&& sigfile
)
694 return cert_append(certfile
, sigfile
);
696 return usage(argv
[0]);
699 return cert_dump(certfile
);
701 return usage(argv
[0]);
703 if (certfile
&& pubkeyfile
&& seckeyfile
)
704 return cert_issue(certfile
, pubkeyfile
, seckeyfile
);
706 return usage(argv
[0]);
708 if (certfile
&& pubkeydir
)
709 return cert_process_revoker(certfile
, pubkeydir
);
711 return usage(argv
[0]);
713 if (certfile
&& (pubkeyfile
|| pubkeydir
))
714 return cert_verify(certfile
, pubkeyfile
, pubkeydir
, msgfile
);
716 return usage(argv
[0]);
718 return usage(argv
[0]);
722 return usage(argv
[0]);