1 /* 2 * Public Domain poly1305 from Andrew Moon 3 * poly1305-donna-unrolled.c from https://github.com/floodyberry/poly1305-donna 4 */ 5 6 /* $OpenBSD: poly1305.c,v 1.3 2013/12/19 22:57:13 djm Exp $ */ 7 8 #include "includes.h" 9 10 #include <sys/types.h> 11 #ifdef HAVE_STDINT_H 12 # include <stdint.h> 13 #endif 14 15 #include "poly1305.h" 16 17 #define mul32x32_64(a,b) ((uint64_t)(a) * (b)) 18 19 #define U8TO32_LE(p) \ 20 (((uint32_t)((p)[0])) | \ 21 ((uint32_t)((p)[1]) << 8) | \ 22 ((uint32_t)((p)[2]) << 16) | \ 23 ((uint32_t)((p)[3]) << 24)) 24 25 #define U32TO8_LE(p, v) \ 26 do { \ 27 (p)[0] = (uint8_t)((v)); \ 28 (p)[1] = (uint8_t)((v) >> 8); \ 29 (p)[2] = (uint8_t)((v) >> 16); \ 30 (p)[3] = (uint8_t)((v) >> 24); \ 31 } while (0) 32 33 void 34 poly1305_auth(unsigned char out[POLY1305_TAGLEN], const unsigned char *m, size_t inlen, const unsigned char key[POLY1305_KEYLEN]) { 35 uint32_t t0,t1,t2,t3; 36 uint32_t h0,h1,h2,h3,h4; 37 uint32_t r0,r1,r2,r3,r4; 38 uint32_t s1,s2,s3,s4; 39 uint32_t b, nb; 40 size_t j; 41 uint64_t t[5]; 42 uint64_t f0,f1,f2,f3; 43 uint32_t g0,g1,g2,g3,g4; 44 uint64_t c; 45 unsigned char mp[16]; 46 47 /* clamp key */ 48 t0 = U8TO32_LE(key+0); 49 t1 = U8TO32_LE(key+4); 50 t2 = U8TO32_LE(key+8); 51 t3 = U8TO32_LE(key+12); 52 53 /* precompute multipliers */ 54 r0 = t0 & 0x3ffffff; t0 >>= 26; t0 |= t1 << 6; 55 r1 = t0 & 0x3ffff03; t1 >>= 20; t1 |= t2 << 12; 56 r2 = t1 & 0x3ffc0ff; t2 >>= 14; t2 |= t3 << 18; 57 r3 = t2 & 0x3f03fff; t3 >>= 8; 58 r4 = t3 & 0x00fffff; 59 60 s1 = r1 * 5; 61 s2 = r2 * 5; 62 s3 = r3 * 5; 63 s4 = r4 * 5; 64 65 /* init state */ 66 h0 = 0; 67 h1 = 0; 68 h2 = 0; 69 h3 = 0; 70 h4 = 0; 71 72 /* full blocks */ 73 if (inlen < 16) goto poly1305_donna_atmost15bytes; 74 poly1305_donna_16bytes: 75 m += 16; 76 inlen -= 16; 77 78 t0 = U8TO32_LE(m-16); 79 t1 = U8TO32_LE(m-12); 80 t2 = U8TO32_LE(m-8); 81 t3 = U8TO32_LE(m-4); 82 83 h0 += t0 & 0x3ffffff; 84 h1 += ((((uint64_t)t1 << 32) | t0) >> 26) & 0x3ffffff; 85 h2 += ((((uint64_t)t2 << 32) | t1) >> 20) & 0x3ffffff; 86 h3 += ((((uint64_t)t3 << 32) | t2) >> 14) & 0x3ffffff; 87 h4 += (t3 >> 8) | (1 << 24); 88 89 90 poly1305_donna_mul: 91 t[0] = mul32x32_64(h0,r0) + mul32x32_64(h1,s4) + mul32x32_64(h2,s3) + mul32x32_64(h3,s2) + mul32x32_64(h4,s1); 92 t[1] = mul32x32_64(h0,r1) + mul32x32_64(h1,r0) + mul32x32_64(h2,s4) + mul32x32_64(h3,s3) + mul32x32_64(h4,s2); 93 t[2] = mul32x32_64(h0,r2) + mul32x32_64(h1,r1) + mul32x32_64(h2,r0) + mul32x32_64(h3,s4) + mul32x32_64(h4,s3); 94 t[3] = mul32x32_64(h0,r3) + mul32x32_64(h1,r2) + mul32x32_64(h2,r1) + mul32x32_64(h3,r0) + mul32x32_64(h4,s4); 95 t[4] = mul32x32_64(h0,r4) + mul32x32_64(h1,r3) + mul32x32_64(h2,r2) + mul32x32_64(h3,r1) + mul32x32_64(h4,r0); 96 97 h0 = (uint32_t)t[0] & 0x3ffffff; c = (t[0] >> 26); 98 t[1] += c; h1 = (uint32_t)t[1] & 0x3ffffff; b = (uint32_t)(t[1] >> 26); 99 t[2] += b; h2 = (uint32_t)t[2] & 0x3ffffff; b = (uint32_t)(t[2] >> 26); 100 t[3] += b; h3 = (uint32_t)t[3] & 0x3ffffff; b = (uint32_t)(t[3] >> 26); 101 t[4] += b; h4 = (uint32_t)t[4] & 0x3ffffff; b = (uint32_t)(t[4] >> 26); 102 h0 += b * 5; 103 104 if (inlen >= 16) goto poly1305_donna_16bytes; 105 106 /* final bytes */ 107 poly1305_donna_atmost15bytes: 108 if (!inlen) goto poly1305_donna_finish; 109 110 for (j = 0; j < inlen; j++) mp[j] = m[j]; 111 mp[j++] = 1; 112 for (; j < 16; j++) mp[j] = 0; 113 inlen = 0; 114 115 t0 = U8TO32_LE(mp+0); 116 t1 = U8TO32_LE(mp+4); 117 t2 = U8TO32_LE(mp+8); 118 t3 = U8TO32_LE(mp+12); 119 120 h0 += t0 & 0x3ffffff; 121 h1 += ((((uint64_t)t1 << 32) | t0) >> 26) & 0x3ffffff; 122 h2 += ((((uint64_t)t2 << 32) | t1) >> 20) & 0x3ffffff; 123 h3 += ((((uint64_t)t3 << 32) | t2) >> 14) & 0x3ffffff; 124 h4 += (t3 >> 8); 125 126 goto poly1305_donna_mul; 127 128 poly1305_donna_finish: 129 b = h0 >> 26; h0 = h0 & 0x3ffffff; 130 h1 += b; b = h1 >> 26; h1 = h1 & 0x3ffffff; 131 h2 += b; b = h2 >> 26; h2 = h2 & 0x3ffffff; 132 h3 += b; b = h3 >> 26; h3 = h3 & 0x3ffffff; 133 h4 += b; b = h4 >> 26; h4 = h4 & 0x3ffffff; 134 h0 += b * 5; b = h0 >> 26; h0 = h0 & 0x3ffffff; 135 h1 += b; 136 137 g0 = h0 + 5; b = g0 >> 26; g0 &= 0x3ffffff; 138 g1 = h1 + b; b = g1 >> 26; g1 &= 0x3ffffff; 139 g2 = h2 + b; b = g2 >> 26; g2 &= 0x3ffffff; 140 g3 = h3 + b; b = g3 >> 26; g3 &= 0x3ffffff; 141 g4 = h4 + b - (1 << 26); 142 143 b = (g4 >> 31) - 1; 144 nb = ~b; 145 h0 = (h0 & nb) | (g0 & b); 146 h1 = (h1 & nb) | (g1 & b); 147 h2 = (h2 & nb) | (g2 & b); 148 h3 = (h3 & nb) | (g3 & b); 149 h4 = (h4 & nb) | (g4 & b); 150 151 f0 = ((h0 ) | (h1 << 26)) + (uint64_t)U8TO32_LE(&key[16]); 152 f1 = ((h1 >> 6) | (h2 << 20)) + (uint64_t)U8TO32_LE(&key[20]); 153 f2 = ((h2 >> 12) | (h3 << 14)) + (uint64_t)U8TO32_LE(&key[24]); 154 f3 = ((h3 >> 18) | (h4 << 8)) + (uint64_t)U8TO32_LE(&key[28]); 155 156 U32TO8_LE(&out[ 0], f0); f1 += (f0 >> 32); 157 U32TO8_LE(&out[ 4], f1); f2 += (f1 >> 32); 158 U32TO8_LE(&out[ 8], f2); f3 += (f2 >> 32); 159 U32TO8_LE(&out[12], f3); 160 } 161
