File Coverage

src/ec/ecdsa_i31_bits.c

Criterion	Covered	Total	%
statement	10	12	83.3
branch	1	2	50.0
condition			n/a
subroutine			n/a
pod			n/a
total	11	14	78.5

line	stmt	bran	code
1			/*
2			* Copyright (c) 2016 Thomas Pornin
3			*
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:
11			*
12			* The above copyright notice and this permission notice shall be
13			* included in all copies or substantial portions of the Software.
14			*
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
22			* SOFTWARE.
23			*/
24
25			#include "inner.h"
26
27			/* see inner.h */
28			void
29	3		br_ecdsa_i31_bits2int(uint32_t *x,
30			const void *src, size_t len, uint32_t ebitlen)
31			{
32			uint32_t bitlen, hbitlen;
33			int sc;
34
35	3		bitlen = ebitlen - (ebitlen >> 5);
36	3		hbitlen = (uint32_t)len << 3;
37	3	50	if (hbitlen > bitlen) {
38	0		len = (bitlen + 7) >> 3;
39	0		sc = (int)((hbitlen - bitlen) & 7);
40			} else {
41	3		sc = 0;
42			}
43	3		br_i31_zero(x, ebitlen);
44	3		br_i31_decode(x, src, len);
45	3		br_i31_rshift(x, sc);
46	3		x[0] = ebitlen;
47	3		}