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 int 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(bufpt
, 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
]) {
375 for (i
= 0; i
< CERT_ATTR_MAX
; i
++) {
376 struct blob_attr
*v
= cert
[i
];
381 switch(cert_policy
[i
].type
) {
382 case BLOB_ATTR_BINARY
:
383 fprintf(stdout
, "signature:\n---\n%s---\n", (char *) blob_data(v
));
385 case BLOB_ATTR_NESTED
:
386 fprintf(stdout
, "payload:\n---\n%s\n---\n", blobmsg_format_json_indent(blob_data(v
), false, 0));
392 /* dump certfile to console */
393 static int cert_dump(const char *certfile
) {
394 struct cert_object
*cobj
;
395 static LIST_HEAD(certchain
);
396 unsigned int count
= 0;
398 if (cert_load(certfile
, &certchain
)) {
399 DPRINTF("cannot parse cert\n");
403 list_for_each_entry(cobj
, &certchain
, list
) {
404 fprintf(stdout
, "=== CHAIN ELEMENT %02u ===\n", ++count
);
405 cert_dump_blob(cobj
->cert
);
411 /* issue an auth certificate for pubkey */
412 static int cert_issue(const char *certfile
, const char *pubkeyfile
, const char *seckeyfile
) {
413 struct blob_buf payloadbuf
= {0};
414 struct blob_buf certbuf
= {0};
422 char fname
[256], sfname
[256];
424 char tmpdir
[] = "/tmp/ucert-XXXXXX";
426 pkf
= fopen(pubkeyfile
, "r");
430 pklen
= fread(pkb
, 1, 512, pkf
);
438 if (usign_f_pubkey(pkfp
, pubkeyfile
))
441 gettimeofday(&tv
, NULL
);
443 if (mkdtemp(tmpdir
) == NULL
)
446 while (revoker
>= 0) {
447 blob_buf_init(&payloadbuf
, 0);
448 c
= blobmsg_open_table(&payloadbuf
, "ucert");
449 blobmsg_add_u32(&payloadbuf
, "certtype", revoker
?CERTTYPE_REVOKE
:CERTTYPE_AUTH
);
450 blobmsg_add_u64(&payloadbuf
, "validfrom", tv
.tv_sec
);
452 blobmsg_add_u64(&payloadbuf
, "expiresat", tv
.tv_sec
+ 60 * 60 * 24 * 365);
453 blobmsg_add_string(&payloadbuf
, "pubkey", pkb
);
455 blobmsg_add_string(&payloadbuf
, "fingerprint", pkfp
);
458 blobmsg_close_table(&payloadbuf
, c
);
460 snprintf(fname
, sizeof(fname
) - 1, "%s/%s", tmpdir
, revoker
?"revoker":"payload");
461 write_file(fname
, blob_data(payloadbuf
.head
), blob_len(payloadbuf
.head
), false);
463 snprintf(sfname
, sizeof(sfname
) - 1, "%s/%s", tmpdir
, revoker
?"revoker.sig":"payload.sig");
464 if (usign_s(fname
, seckeyfile
, sfname
, quiet
))
467 sigf
= fopen(sfname
, "r");
471 siglen
= fread(sigb
, 1, 1024, sigf
);
481 blob_buf_init(&certbuf
, 0);
482 blob_put(&certbuf
, CERT_ATTR_SIGNATURE
, sigb
, siglen
);
483 blob_put(&certbuf
, CERT_ATTR_PAYLOAD
, blob_data(payloadbuf
.head
), blob_len(payloadbuf
.head
));
484 snprintf(fname
, sizeof(fname
) - 1, "%s%s", certfile
, revoker
?".revoke":"");
485 write_file(fname
, certbuf
.head
, blob_raw_len(certbuf
.head
), true);
486 blob_buf_free(&certbuf
);
487 blob_buf_free(&payloadbuf
);
498 /* process revoker certificate */
499 static int cert_process_revoker(const char *certfile
, const char *pubkeydir
) {
500 static LIST_HEAD(certchain
);
501 struct cert_object
*cobj
;
502 struct blob_attr
*containertb
[CERT_CT_ATTR_MAX
];
503 struct blob_attr
*payloadtb
[CERT_PL_ATTR_MAX
];
507 enum certtype_id certtype
;
513 if (cert_load(certfile
, &certchain
)) {
514 DPRINTF("cannot parse cert\n");
518 gettimeofday(&tv
, NULL
);
520 list_for_each_entry(cobj
, &certchain
, list
) {
521 if (!cobj
->cert
[CERT_ATTR_PAYLOAD
])
524 /* blob has payload, verify that using signature */
525 ret
= cert_verify_blob(cobj
->cert
, NULL
, pubkeydir
);
529 blobmsg_parse(cert_cont_policy
,
530 ARRAY_SIZE(cert_cont_policy
),
532 blob_data(cobj
->cert
[CERT_ATTR_PAYLOAD
]),
533 blob_len(cobj
->cert
[CERT_ATTR_PAYLOAD
]));
534 if (!containertb
[CERT_CT_ATTR_PAYLOAD
]) {
535 DPRINTF("no ucert in signed payload\n");
539 blobmsg_parse(cert_payload_policy
,
540 ARRAY_SIZE(cert_payload_policy
),
542 blobmsg_data(containertb
[CERT_CT_ATTR_PAYLOAD
]),
543 blobmsg_data_len(containertb
[CERT_CT_ATTR_PAYLOAD
]));
545 if (!payloadtb
[CERT_PL_ATTR_CERTTYPE
] ||
546 !payloadtb
[CERT_PL_ATTR_VALIDFROMTIME
] ||
547 !payloadtb
[CERT_PL_ATTR_KEY_FINGERPRINT
]) {
548 DPRINTF("missing mandatory ucert attributes\n");
552 certtype
= blobmsg_get_u32(payloadtb
[CERT_PL_ATTR_CERTTYPE
]);
553 validfrom
= blobmsg_get_u64(payloadtb
[CERT_PL_ATTR_VALIDFROMTIME
]);
554 fingerprint
= blobmsg_get_string(payloadtb
[CERT_PL_ATTR_KEY_FINGERPRINT
]);
556 if (certtype
!= CERTTYPE_REVOKE
) {
557 DPRINTF("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
)) {
569 DPRINTF("existing revoker deadlink for key %s\n", fingerprint
);
573 /* remove any other entry */
578 ret
= symlink(".revoked.", rfname
);
582 DPRINTF("created revoker deadlink for key %s\n", fingerprint
);
588 /* load and verify certfile (and message) */
589 static int cert_verify(const char *certfile
, const char *pubkeyfile
, const char *pubkeydir
, const char *msgfile
) {
590 static LIST_HEAD(certchain
);
592 if (cert_load(certfile
, &certchain
)) {
593 DPRINTF("cannot parse cert\n");
597 return chain_verify(msgfile
, pubkeyfile
, pubkeydir
, &certchain
);
601 static int usage(const char *cmd
)
603 #ifndef UCERT_STRIP_MESSAGES
605 "Usage: %s <command> <options>\n"
608 " -A: append signature (needs -c and -x)\n"
609 " -D: dump (needs -c)\n"
610 " -I: issue cert and revoker (needs -c and -p and -s)\n"
611 #endif /* UCERT_FULL */
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"
621 " -s <file>: secret key file (issue only)\n"
622 " -x <file>: signature file (append only)\n"
623 #endif /* UCERT_FULL */
626 #endif /* UCERT_STRIP_MESSAGES */
630 /* parse command line options and call functions */
631 int main(int argc
, char *argv
[]) {
633 const char *msgfile
= NULL
;
634 const char *pubkeyfile
= NULL
;
635 const char *pubkeydir
= NULL
;
636 const char *certfile
= NULL
;
638 const char *sigfile
= NULL
;
639 const char *seckeyfile
= NULL
;
643 while ((ch
= getopt(argc
, argv
,
653 return usage(argv
[0]);
658 return usage(argv
[0]);
663 return usage(argv
[0]);
669 return usage(argv
[0]);
674 return usage(argv
[0]);
678 if (certfile
|| cmd
== CMD_NONE
)
679 return usage(argv
[0]);
683 if (msgfile
|| cmd
!= CMD_VERIFY
)
684 return usage(argv
[0]);
688 if (pubkeyfile
|| (cmd
!= CMD_VERIFY
&& cmd
!= CMD_ISSUE
) || cmd
== CMD_NONE
)
689 return usage(argv
[0]);
693 if (pubkeydir
|| (cmd
!= CMD_VERIFY
&& cmd
!= CMD_REVOKE
) || cmd
== CMD_NONE
)
694 return usage(argv
[0]);
699 return usage(argv
[0]);
704 if (seckeyfile
|| cmd
!= CMD_ISSUE
|| cmd
== CMD_NONE
)
705 return usage(argv
[0]);
709 if (sigfile
|| cmd
!= CMD_APPEND
|| cmd
== CMD_NONE
)
710 return usage(argv
[0]);
715 return usage(argv
[0]);
722 if (certfile
&& sigfile
)
723 return cert_append(certfile
, sigfile
);
725 return usage(argv
[0]);
728 return cert_dump(certfile
);
730 return usage(argv
[0]);
732 if (certfile
&& pubkeyfile
&& seckeyfile
)
733 return cert_issue(certfile
, pubkeyfile
, seckeyfile
);
735 return usage(argv
[0]);
738 if (certfile
&& pubkeydir
)
739 return cert_process_revoker(certfile
, pubkeydir
);
741 return usage(argv
[0]);
743 if (certfile
&& (pubkeyfile
|| pubkeydir
))
744 return cert_verify(certfile
, pubkeyfile
, pubkeydir
, msgfile
);
746 return usage(argv
[0]);
748 return usage(argv
[0]);
752 return usage(argv
[0]);