71f0d3902886ff0c94db4022620515fe39ccee95
2 * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
4 * Permission is hereby granted, free of charge, to any person obtaining
5 * a copy of this software and associated documentation files (the
6 * "Software"), to deal in the Software without restriction, including
7 * without limitation the rights to use, copy, modify, merge, publish,
8 * distribute, sublicense, and/or sell copies of the Software, and to
9 * permit persons to whom the Software is furnished to do so, subject to
10 * the following conditions:
12 * The above copyright notice and this permission notice shall be
13 * included in all copies or substantial portions of the Software.
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
19 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
20 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
28 asn1_int_length(const unsigned char *x
, size_t xlen
)
30 while (xlen
> 0 && *x
== 0) {
34 if (xlen
== 0 || *x
>= 0x80) {
40 /* see bearssl_ec.h */
42 br_ecdsa_raw_to_asn1(void *sig
, size_t sig_len
)
45 * Internal buffer is large enough to accommodate a signature
46 * such that r and s fit on 125 bytes each (signed encoding),
47 * meaning a curve order of up to 1000 bits. This is the limit
48 * that ensures "simple" length encodings.
51 size_t hlen
, rlen
, slen
, zlen
, off
;
52 unsigned char tmp
[257];
55 if ((sig_len
& 1) != 0) {
59 rlen
= asn1_int_length(buf
, hlen
);
60 slen
= asn1_int_length(buf
+ hlen
, hlen
);
61 if (rlen
> 125 || slen
> 125) {
65 zlen
= rlen
+ slen
+ 4;
78 memcpy(tmp
+ off
+ 1, buf
, hlen
);
80 memcpy(tmp
+ off
, buf
+ hlen
- rlen
, rlen
);
87 memcpy(tmp
+ off
+ 1, buf
+ hlen
, hlen
);
89 memcpy(tmp
+ off
, buf
+ sig_len
- slen
, slen
);
92 memcpy(sig
, tmp
, off
);