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| 1 /* This Source Code Form is subject to the terms of the Mozilla Public |
| 2 * License, v. 2.0. If a copy of the MPL was not distributed with this |
| 3 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ |
| 4 |
| 5 /* This implementation of poly1305 is by Andrew Moon |
| 6 * (https://github.com/floodyberry/poly1305-donna) and released as public |
| 7 * domain. */ |
| 8 |
| 9 #include <string.h> |
| 10 #include <stdint.h> |
| 11 |
| 12 #include "poly1305.h" |
| 13 |
| 14 #if defined(NSS_X86) || defined(NSS_X64) |
| 15 /* We can assume little-endian. */ |
| 16 static uint32_t U8TO32_LE(const unsigned char *m) { |
| 17 uint32_t r; |
| 18 memcpy(&r, m, sizeof(r)); |
| 19 return r; |
| 20 } |
| 21 |
| 22 static void U32TO8_LE(unsigned char *m, uint32_t v) { |
| 23 memcpy(m, &v, sizeof(v)); |
| 24 } |
| 25 #else |
| 26 static void U8TO32_LE(const unsigned char *m) { |
| 27 return (uint32_t)m[0] | |
| 28 (uint32_t)m[1] << 8 | |
| 29 (uint32_t)m[2] << 16 | |
| 30 (uint32_t)m[3] << 24; |
| 31 } |
| 32 |
| 33 static void U32TO8_LE(unsigned char *m, uint32_t v) { |
| 34 m[0] = v; |
| 35 m[1] = v >> 8; |
| 36 m[2] = v >> 16; |
| 37 m[3] = v >> 24; |
| 38 } |
| 39 #endif |
| 40 |
| 41 static uint64_t |
| 42 mul32x32_64(uint32_t a, uint32_t b) { |
| 43 return (uint64_t)a * b; |
| 44 } |
| 45 |
| 46 struct poly1305_state_st { |
| 47 uint32_t r0,r1,r2,r3,r4; |
| 48 uint32_t s1,s2,s3,s4; |
| 49 uint32_t h0,h1,h2,h3,h4; |
| 50 unsigned char buf[16]; |
| 51 unsigned int buf_used; |
| 52 unsigned char key[16]; |
| 53 }; |
| 54 |
| 55 /* update updates |state| given some amount of input data. This function may |
| 56 * only be called with a |len| that is not a multiple of 16 at the end of the |
| 57 * data. Otherwise the input must be buffered into 16 byte blocks. */ |
| 58 static void update(struct poly1305_state_st *state, const unsigned char *in, |
| 59 size_t len) { |
| 60 uint32_t t0,t1,t2,t3; |
| 61 uint64_t t[5]; |
| 62 uint32_t b; |
| 63 uint64_t c; |
| 64 size_t j; |
| 65 unsigned char mp[16]; |
| 66 |
| 67 if (len < 16) |
| 68 goto poly1305_donna_atmost15bytes; |
| 69 |
| 70 poly1305_donna_16bytes: |
| 71 t0 = U8TO32_LE(in); |
| 72 t1 = U8TO32_LE(in+4); |
| 73 t2 = U8TO32_LE(in+8); |
| 74 t3 = U8TO32_LE(in+12); |
| 75 |
| 76 in += 16; |
| 77 len -= 16; |
| 78 |
| 79 state->h0 += t0 & 0x3ffffff; |
| 80 state->h1 += ((((uint64_t)t1 << 32) | t0) >> 26) & 0x3ffffff; |
| 81 state->h2 += ((((uint64_t)t2 << 32) | t1) >> 20) & 0x3ffffff; |
| 82 state->h3 += ((((uint64_t)t3 << 32) | t2) >> 14) & 0x3ffffff; |
| 83 state->h4 += (t3 >> 8) | (1 << 24); |
| 84 |
| 85 poly1305_donna_mul: |
| 86 t[0] = mul32x32_64(state->h0,state->r0) + |
| 87 mul32x32_64(state->h1,state->s4) + |
| 88 mul32x32_64(state->h2,state->s3) + |
| 89 mul32x32_64(state->h3,state->s2) + |
| 90 mul32x32_64(state->h4,state->s1); |
| 91 t[1] = mul32x32_64(state->h0,state->r1) + |
| 92 mul32x32_64(state->h1,state->r0) + |
| 93 mul32x32_64(state->h2,state->s4) + |
| 94 mul32x32_64(state->h3,state->s3) + |
| 95 mul32x32_64(state->h4,state->s2); |
| 96 t[2] = mul32x32_64(state->h0,state->r2) + |
| 97 mul32x32_64(state->h1,state->r1) + |
| 98 mul32x32_64(state->h2,state->r0) + |
| 99 mul32x32_64(state->h3,state->s4) + |
| 100 mul32x32_64(state->h4,state->s3); |
| 101 t[3] = mul32x32_64(state->h0,state->r3) + |
| 102 mul32x32_64(state->h1,state->r2) + |
| 103 mul32x32_64(state->h2,state->r1) + |
| 104 mul32x32_64(state->h3,state->r0) + |
| 105 mul32x32_64(state->h4,state->s4); |
| 106 t[4] = mul32x32_64(state->h0,state->r4) + |
| 107 mul32x32_64(state->h1,state->r3) + |
| 108 mul32x32_64(state->h2,state->r2) + |
| 109 mul32x32_64(state->h3,state->r1) + |
| 110 mul32x32_64(state->h4,state->r0); |
| 111 |
| 112 state->h0 = (uint32_t)t[0] & 0x3ffffff; c = (t[0] >
> 26); |
| 113 t[1] += c; state->h1 = (uint32_t)t[1] & 0x3ffffff; b = (uint32_t)(t[1] >
> 26); |
| 114 t[2] += b; state->h2 = (uint32_t)t[2] & 0x3ffffff; b = (uint32_t)(t[2] >
> 26); |
| 115 t[3] += b; state->h3 = (uint32_t)t[3] & 0x3ffffff; b = (uint32_t)(t[3] >
> 26); |
| 116 t[4] += b; state->h4 = (uint32_t)t[4] & 0x3ffffff; b = (uint32_t)(t[4] >
> 26); |
| 117 state->h0 += b * 5; |
| 118 |
| 119 if (len >= 16) |
| 120 goto poly1305_donna_16bytes; |
| 121 |
| 122 /* final bytes */ |
| 123 poly1305_donna_atmost15bytes: |
| 124 if (!len) |
| 125 return; |
| 126 |
| 127 for (j = 0; j < len; j++) |
| 128 mp[j] = in[j]; |
| 129 mp[j++] = 1; |
| 130 for (; j < 16; j++) |
| 131 mp[j] = 0; |
| 132 len = 0; |
| 133 |
| 134 t0 = U8TO32_LE(mp+0); |
| 135 t1 = U8TO32_LE(mp+4); |
| 136 t2 = U8TO32_LE(mp+8); |
| 137 t3 = U8TO32_LE(mp+12); |
| 138 |
| 139 state->h0 += t0 & 0x3ffffff; |
| 140 state->h1 += ((((uint64_t)t1 << 32) | t0) >> 26) & 0x3ffffff; |
| 141 state->h2 += ((((uint64_t)t2 << 32) | t1) >> 20) & 0x3ffffff; |
| 142 state->h3 += ((((uint64_t)t3 << 32) | t2) >> 14) & 0x3ffffff; |
| 143 state->h4 += (t3 >> 8); |
| 144 |
| 145 goto poly1305_donna_mul; |
| 146 } |
| 147 |
| 148 void Poly1305Init(poly1305_state *statep, const unsigned char key[32]) { |
| 149 struct poly1305_state_st *state = (struct poly1305_state_st*) statep; |
| 150 uint32_t t0,t1,t2,t3; |
| 151 |
| 152 t0 = U8TO32_LE(key+0); |
| 153 t1 = U8TO32_LE(key+4); |
| 154 t2 = U8TO32_LE(key+8); |
| 155 t3 = U8TO32_LE(key+12); |
| 156 |
| 157 /* precompute multipliers */ |
| 158 state->r0 = t0 & 0x3ffffff; t0 >>= 26; t0 |= t1 << 6; |
| 159 state->r1 = t0 & 0x3ffff03; t1 >>= 20; t1 |= t2 << 12; |
| 160 state->r2 = t1 & 0x3ffc0ff; t2 >>= 14; t2 |= t3 << 18; |
| 161 state->r3 = t2 & 0x3f03fff; t3 >>= 8; |
| 162 state->r4 = t3 & 0x00fffff; |
| 163 |
| 164 state->s1 = state->r1 * 5; |
| 165 state->s2 = state->r2 * 5; |
| 166 state->s3 = state->r3 * 5; |
| 167 state->s4 = state->r4 * 5; |
| 168 |
| 169 /* init state */ |
| 170 state->h0 = 0; |
| 171 state->h1 = 0; |
| 172 state->h2 = 0; |
| 173 state->h3 = 0; |
| 174 state->h4 = 0; |
| 175 |
| 176 state->buf_used = 0; |
| 177 memcpy(state->key, key + 16, sizeof(state->key)); |
| 178 } |
| 179 |
| 180 void Poly1305Update(poly1305_state *statep, const unsigned char *in, |
| 181 size_t in_len) { |
| 182 unsigned int i; |
| 183 struct poly1305_state_st *state = (struct poly1305_state_st*) statep; |
| 184 |
| 185 if (state->buf_used) { |
| 186 unsigned int todo = 16 - state->buf_used; |
| 187 if (todo > in_len) |
| 188 todo = in_len; |
| 189 for (i = 0; i < todo; i++) |
| 190 state->buf[state->buf_used + i] = in[i]; |
| 191 state->buf_used += todo; |
| 192 in_len -= todo; |
| 193 in += todo; |
| 194 |
| 195 if (state->buf_used == 16) { |
| 196 update(state, state->buf, 16); |
| 197 state->buf_used = 0; |
| 198 } |
| 199 } |
| 200 |
| 201 if (in_len >= 16) { |
| 202 size_t todo = in_len & ~0xf; |
| 203 update(state, in, todo); |
| 204 in += todo; |
| 205 in_len &= 0xf; |
| 206 } |
| 207 |
| 208 if (in_len) { |
| 209 for (i = 0; i < in_len; i++) |
| 210 state->buf[i] = in[i]; |
| 211 state->buf_used = in_len; |
| 212 } |
| 213 } |
| 214 |
| 215 void Poly1305Finish(poly1305_state *statep, unsigned char mac[16]) { |
| 216 struct poly1305_state_st *state = (struct poly1305_state_st*) statep; |
| 217 uint64_t f0,f1,f2,f3; |
| 218 uint32_t g0,g1,g2,g3,g4; |
| 219 uint32_t b, nb; |
| 220 |
| 221 if (state->buf_used) |
| 222 update(state, state->buf, state->buf_used); |
| 223 |
| 224 b = state->h0 >> 26; state->h0 = state->h0 & 0x3ffff
ff; |
| 225 state->h1 += b; b = state->h1 >> 26; state->h1 = state->h1 & 0x3ffff
ff; |
| 226 state->h2 += b; b = state->h2 >> 26; state->h2 = state->h2 & 0x3ffff
ff; |
| 227 state->h3 += b; b = state->h3 >> 26; state->h3 = state->h3 & 0x3ffff
ff; |
| 228 state->h4 += b; b = state->h4 >> 26; state->h4 = state->h4 & 0x3ffff
ff; |
| 229 state->h0 += b * 5; |
| 230 |
| 231 g0 = state->h0 + 5; b = g0 >> 26; g0 &= 0x3ffffff; |
| 232 g1 = state->h1 + b; b = g1 >> 26; g1 &= 0x3ffffff; |
| 233 g2 = state->h2 + b; b = g2 >> 26; g2 &= 0x3ffffff; |
| 234 g3 = state->h3 + b; b = g3 >> 26; g3 &= 0x3ffffff; |
| 235 g4 = state->h4 + b - (1 << 26); |
| 236 |
| 237 b = (g4 >> 31) - 1; |
| 238 nb = ~b; |
| 239 state->h0 = (state->h0 & nb) | (g0 & b); |
| 240 state->h1 = (state->h1 & nb) | (g1 & b); |
| 241 state->h2 = (state->h2 & nb) | (g2 & b); |
| 242 state->h3 = (state->h3 & nb) | (g3 & b); |
| 243 state->h4 = (state->h4 & nb) | (g4 & b); |
| 244 |
| 245 f0 = ((state->h0 ) | (state->h1 << 26)) + (uint64_t)U8TO32_LE(&stat
e->key[0]); |
| 246 f1 = ((state->h1 >> 6) | (state->h2 << 20)) + (uint64_t)U8TO32_LE(&stat
e->key[4]); |
| 247 f2 = ((state->h2 >> 12) | (state->h3 << 14)) + (uint64_t)U8TO32_LE(&stat
e->key[8]); |
| 248 f3 = ((state->h3 >> 18) | (state->h4 << 8)) + (uint64_t)U8TO32_LE(&stat
e->key[12]); |
| 249 |
| 250 U32TO8_LE(&mac[ 0], f0); f1 += (f0 >> 32); |
| 251 U32TO8_LE(&mac[ 4], f1); f2 += (f1 >> 32); |
| 252 U32TO8_LE(&mac[ 8], f2); f3 += (f2 >> 32); |
| 253 U32TO8_LE(&mac[12], f3); |
| 254 } |
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