sys/src/libsec/port/sha2block64.c

   1 /*
   2  * sha2_256 block cipher
   3  *
   4  * Implementation straight from Federal Information Processing Standards
   5  * publication 180-2 (+Change Notice to include SHA-224) August 1, 2002
   6  *   note: the following upper and lower case macro names are distinct
   7  *         and reflect the functions defined in FIPS pub. 180-2.
   8  */
   9
  10 #include <u.h>
  11 #include <libc.h>
  12
  13 #define ROTR(x,n)       (((x) >> (n)) | ((x) << (32-(n))))
  14 #define sigma0(x)       (ROTR((x),7) ^ ROTR((x),18) ^ ((x) >> 3))
  15 #define sigma1(x)       (ROTR((x),17) ^ ROTR((x),19) ^ ((x) >> 10))
  16 #define SIGMA0(x)       (ROTR((x),2) ^ ROTR((x),13) ^ ROTR((x),22))
  17 #define SIGMA1(x)       (ROTR((x),6) ^ ROTR((x),11) ^ ROTR((x),25))
  18 #define Ch(x,y,z)       (((x) & (y)) ^ ((~(x)) & (z)))
  19 #define Maj(x,y,z)      (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)))
  20
  21 /*
  22  * first 32 bits of the fractional parts of cube roots of
  23  * first 64 primes (2..311).
  24  */
  25 static u32int K256[64] = {
  26         0x428a2f98,0x71374491,0xb5c0fbcf,0xe9b5dba5,
  27         0x3956c25b,0x59f111f1,0x923f82a4,0xab1c5ed5,
  28         0xd807aa98,0x12835b01,0x243185be,0x550c7dc3,
  29         0x72be5d74,0x80deb1fe,0x9bdc06a7,0xc19bf174,
  30         0xe49b69c1,0xefbe4786,0x0fc19dc6,0x240ca1cc,
  31         0x2de92c6f,0x4a7484aa,0x5cb0a9dc,0x76f988da,
  32         0x983e5152,0xa831c66d,0xb00327c8,0xbf597fc7,
  33         0xc6e00bf3,0xd5a79147,0x06ca6351,0x14292967,
  34         0x27b70a85,0x2e1b2138,0x4d2c6dfc,0x53380d13,
  35         0x650a7354,0x766a0abb,0x81c2c92e,0x92722c85,
  36         0xa2bfe8a1,0xa81a664b,0xc24b8b70,0xc76c51a3,
  37         0xd192e819,0xd6990624,0xf40e3585,0x106aa070,
  38         0x19a4c116,0x1e376c08,0x2748774c,0x34b0bcb5,
  39         0x391c0cb3,0x4ed8aa4a,0x5b9cca4f,0x682e6ff3,
  40         0x748f82ee,0x78a5636f,0x84c87814,0x8cc70208,
  41         0x90befffa,0xa4506ceb,0xbef9a3f7,0xc67178f2,
  42 };
  43
  44 void
  45 _sha2block64(uchar *p, ulong len, u32int *s)
  46 {
  47         u32int a, b, c, d, e, f, g, h, t1, t2;
  48         u32int *kp, *wp;
  49         u32int w[64];
  50         uchar *end;
  51
  52         /* at this point, we have a multiple of 64 bytes */
  53         for(end = p+len; p < end;){
  54                 a = s[0];
  55                 b = s[1];
  56                 c = s[2];
  57                 d = s[3];
  58                 e = s[4];
  59                 f = s[5];
  60                 g = s[6];
  61                 h = s[7];
  62
  63                 for(wp = w; wp < &w[16]; wp++, p += 4)
  64                         wp[0] = p[0] << 24 | p[1] << 16 | p[2] << 8 | p[3];
  65                 for(; wp < &w[64]; wp++)
  66                         wp[0] = sigma1(wp[-2]) + wp[-7] +
  67                                 sigma0(wp[-15]) + wp[-16];
  68
  69                 for(kp = K256, wp = w; wp < &w[64]; ) {
  70                         t1 = h + SIGMA1(e) + Ch(e,f,g) + *kp++ + *wp++;
  71                         t2 = SIGMA0(a) + Maj(a,b,c);
  72                         h = g;
  73                         g = f;
  74                         f = e;
  75                         e = d + t1;
  76                         d = c;
  77                         c = b;
  78                         b = a;
  79                         a = t1 + t2;
  80                 }
  81
  82                 /* save state */
  83                 s[0] += a;
  84                 s[1] += b;
  85                 s[2] += c;
  86                 s[3] += d;
  87                 s[4] += e;
  88                 s[5] += f;
  89                 s[6] += g;
  90                 s[7] += h;
  91         }
  92 }