ref: 7d7650dffc20c3853eb1acd551c9a02f73751ae3
dir: /sys/src/libsec/port/sha2block64.c/
/*
* sha2_256 block cipher
*
* Implementation straight from Federal Information Processing Standards
* publication 180-2 (+Change Notice to include SHA-224) August 1, 2002
* note: the following upper and lower case macro names are distinct
* and reflect the functions defined in FIPS pub. 180-2.
*/
#include <u.h>
#include <libc.h>
#define ROTR(x,n) (((x) >> (n)) | ((x) << (32-(n))))
#define sigma0(x) (ROTR((x),7) ^ ROTR((x),18) ^ ((x) >> 3))
#define sigma1(x) (ROTR((x),17) ^ ROTR((x),19) ^ ((x) >> 10))
#define SIGMA0(x) (ROTR((x),2) ^ ROTR((x),13) ^ ROTR((x),22))
#define SIGMA1(x) (ROTR((x),6) ^ ROTR((x),11) ^ ROTR((x),25))
#define Ch(x,y,z) (((x) & (y)) ^ ((~(x)) & (z)))
#define Maj(x,y,z) (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)))
/*
* first 32 bits of the fractional parts of cube roots of
* first 64 primes (2..311).
*/
static u32int K256[64] = {
0x428a2f98,0x71374491,0xb5c0fbcf,0xe9b5dba5,
0x3956c25b,0x59f111f1,0x923f82a4,0xab1c5ed5,
0xd807aa98,0x12835b01,0x243185be,0x550c7dc3,
0x72be5d74,0x80deb1fe,0x9bdc06a7,0xc19bf174,
0xe49b69c1,0xefbe4786,0x0fc19dc6,0x240ca1cc,
0x2de92c6f,0x4a7484aa,0x5cb0a9dc,0x76f988da,
0x983e5152,0xa831c66d,0xb00327c8,0xbf597fc7,
0xc6e00bf3,0xd5a79147,0x06ca6351,0x14292967,
0x27b70a85,0x2e1b2138,0x4d2c6dfc,0x53380d13,
0x650a7354,0x766a0abb,0x81c2c92e,0x92722c85,
0xa2bfe8a1,0xa81a664b,0xc24b8b70,0xc76c51a3,
0xd192e819,0xd6990624,0xf40e3585,0x106aa070,
0x19a4c116,0x1e376c08,0x2748774c,0x34b0bcb5,
0x391c0cb3,0x4ed8aa4a,0x5b9cca4f,0x682e6ff3,
0x748f82ee,0x78a5636f,0x84c87814,0x8cc70208,
0x90befffa,0xa4506ceb,0xbef9a3f7,0xc67178f2,
};
void
_sha2block64(uchar *p, ulong len, u32int *s)
{
u32int a, b, c, d, e, f, g, h, t1, t2;
u32int *kp, *wp;
u32int w[64];
uchar *end;
/* at this point, we have a multiple of 64 bytes */
for(end = p+len; p < end;){
a = s[0];
b = s[1];
c = s[2];
d = s[3];
e = s[4];
f = s[5];
g = s[6];
h = s[7];
for(wp = w; wp < &w[16]; wp++, p += 4)
wp[0] = p[0] << 24 | p[1] << 16 | p[2] << 8 | p[3];
for(; wp < &w[64]; wp++)
wp[0] = sigma1(wp[-2]) + wp[-7] +
sigma0(wp[-15]) + wp[-16];
for(kp = K256, wp = w; wp < &w[64]; ) {
t1 = h + SIGMA1(e) + Ch(e,f,g) + *kp++ + *wp++;
t2 = SIGMA0(a) + Maj(a,b,c);
h = g;
g = f;
f = e;
e = d + t1;
d = c;
c = b;
b = a;
a = t1 + t2;
}
/* save state */
s[0] += a;
s[1] += b;
s[2] += c;
s[3] += d;
s[4] += e;
s[5] += f;
s[6] += g;
s[7] += h;
}
}