3 Copyright: 2012-2013 Andrew M. (floodyberry)
4 Copyright: 2013 Nikos Mavrogiannopoulos
5 Copyright: 2013 Niels Möller
7 This file is part of GNU Nettle.
9 GNU Nettle is free software: you can redistribute it and/or
10 modify it under the terms of either:
12 * the GNU Lesser General Public License as published by the Free
13 Software Foundation; either version 3 of the License, or (at your
14 option) any later version.
18 * the GNU General Public License as published by the Free
19 Software Foundation; either version 2 of the License, or (at your
20 option) any later version.
22 or both in parallel, as here.
24 GNU Nettle is distributed in the hope that it will be useful,
25 but WITHOUT ANY WARRANTY; without even the implied warranty of
26 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
27 General Public License for more details.
29 You should have received copies of the GNU General Public License and
30 the GNU Lesser General Public License along with this program. If
31 not, see http://www.gnu.org/licenses/.
34 /* Based on https://github.com/floodyberry/poly1305-donna.
35 * Modified for nettle by Nikos Mavrogiannopoulos and Niels Möller.
36 * Original license notice:
38 * Permission is hereby granted, free of charge, to any person obtaining a
39 * copy of this software and associated documentation files (the
40 * "Software"), to deal in the Software without restriction, including
41 * without limitation the rights to use, copy, modify, merge, publish,
42 * distribute, sublicense, and/or sell copies of the Software, and to
43 * permit persons to whom the Software is furnished to do so, subject to
44 * the following conditions:
46 * The above copyright notice and this permission notice shall be included
47 * in all copies or substantial portions of the Software.
49 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
50 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
51 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
52 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
53 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
54 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
55 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
69 #define mul32x32_64(a,b) ((uint64_t)(a) * (b))
88 poly1305_set_key(struct poly1305_ctx *ctx, const uint8_t key[16])
92 t0 = LE_READ_UINT32(key);
93 t1 = LE_READ_UINT32(key+4);
94 t2 = LE_READ_UINT32(key+8);
95 t3 = LE_READ_UINT32(key+12);
97 ctx->r0 = t0 & 0x3ffffff; t0 >>= 26; t0 |= t1 << 6;
98 ctx->r1 = t0 & 0x3ffff03; t1 >>= 20; t1 |= t2 << 12;
99 ctx->r2 = t1 & 0x3ffc0ff; t2 >>= 14; t2 |= t3 << 18;
100 ctx->r3 = t2 & 0x3f03fff; t3 >>= 8;
101 ctx->r4 = t3 & 0x00fffff;
103 ctx->s1 = ctx->r1 * 5;
104 ctx->s2 = ctx->r2 * 5;
105 ctx->s3 = ctx->r3 * 5;
106 ctx->s4 = ctx->r4 * 5;
116 _poly1305_block (struct poly1305_ctx *ctx, const uint8_t *m, unsigned t4)
118 uint32_t t0,t1,t2,t3;
123 t0 = LE_READ_UINT32(m);
124 t1 = LE_READ_UINT32(m+4);
125 t2 = LE_READ_UINT32(m+8);
126 t3 = LE_READ_UINT32(m+12);
128 ctx->h0 += t0 & 0x3ffffff;
129 ctx->h1 += ((((uint64_t)t1 << 32) | t0) >> 26) & 0x3ffffff;
130 ctx->h2 += ((((uint64_t)t2 << 32) | t1) >> 20) & 0x3ffffff;
131 ctx->h3 += ((((uint64_t)t3 << 32) | t2) >> 14) & 0x3ffffff;
132 ctx->h4 += (t3 >> 8) | ((uint32_t) t4 << 24);
134 /* poly1305_donna_mul: */
135 t[0] = mul32x32_64(ctx->h0,ctx->r0) + mul32x32_64(ctx->h1,ctx->s4) + mul32x32_64(ctx->h2,ctx->s3) + mul32x32_64(ctx->h3,ctx->s2) + mul32x32_64(ctx->h4,ctx->s1);
136 t[1] = mul32x32_64(ctx->h0,ctx->r1) + mul32x32_64(ctx->h1,ctx->r0) + mul32x32_64(ctx->h2,ctx->s4) + mul32x32_64(ctx->h3,ctx->s3) + mul32x32_64(ctx->h4,ctx->s2);
137 t[2] = mul32x32_64(ctx->h0,ctx->r2) + mul32x32_64(ctx->h1,ctx->r1) + mul32x32_64(ctx->h2,ctx->r0) + mul32x32_64(ctx->h3,ctx->s4) + mul32x32_64(ctx->h4,ctx->s3);
138 t[3] = mul32x32_64(ctx->h0,ctx->r3) + mul32x32_64(ctx->h1,ctx->r2) + mul32x32_64(ctx->h2,ctx->r1) + mul32x32_64(ctx->h3,ctx->r0) + mul32x32_64(ctx->h4,ctx->s4);
139 t[4] = mul32x32_64(ctx->h0,ctx->r4) + mul32x32_64(ctx->h1,ctx->r3) + mul32x32_64(ctx->h2,ctx->r2) + mul32x32_64(ctx->h3,ctx->r1) + mul32x32_64(ctx->h4,ctx->r0);
141 ctx->h0 = (uint32_t)t[0] & 0x3ffffff; c = (t[0] >> 26);
142 t[1] += c; ctx->h1 = (uint32_t)t[1] & 0x3ffffff; b = (uint32_t)(t[1] >> 26);
143 t[2] += b; ctx->h2 = (uint32_t)t[2] & 0x3ffffff; b = (uint32_t)(t[2] >> 26);
144 t[3] += b; ctx->h3 = (uint32_t)t[3] & 0x3ffffff; b = (uint32_t)(t[3] >> 26);
145 t[4] += b; ctx->h4 = (uint32_t)t[4] & 0x3ffffff; b = (uint32_t)(t[4] >> 26);
149 /* Adds digest to the nonce */
151 poly1305_digest (struct poly1305_ctx *ctx, union nettle_block16 *s)
154 uint64_t f0,f1,f2,f3;
155 uint32_t g0,g1,g2,g3,g4;
157 b = ctx->h0 >> 26; ctx->h0 = ctx->h0 & 0x3ffffff;
158 ctx->h1 += b; b = ctx->h1 >> 26; ctx->h1 = ctx->h1 & 0x3ffffff;
159 ctx->h2 += b; b = ctx->h2 >> 26; ctx->h2 = ctx->h2 & 0x3ffffff;
160 ctx->h3 += b; b = ctx->h3 >> 26; ctx->h3 = ctx->h3 & 0x3ffffff;
161 ctx->h4 += b; b = ctx->h4 >> 26; ctx->h4 = ctx->h4 & 0x3ffffff;
162 ctx->h0 += b * 5; b = ctx->h0 >> 26; ctx->h0 = ctx->h0 & 0x3ffffff;
165 g0 = ctx->h0 + 5; b = g0 >> 26; g0 &= 0x3ffffff;
166 g1 = ctx->h1 + b; b = g1 >> 26; g1 &= 0x3ffffff;
167 g2 = ctx->h2 + b; b = g2 >> 26; g2 &= 0x3ffffff;
168 g3 = ctx->h3 + b; b = g3 >> 26; g3 &= 0x3ffffff;
169 g4 = ctx->h4 + b - (1 << 26);
173 ctx->h0 = (ctx->h0 & nb) | (g0 & b);
174 ctx->h1 = (ctx->h1 & nb) | (g1 & b);
175 ctx->h2 = (ctx->h2 & nb) | (g2 & b);
176 ctx->h3 = (ctx->h3 & nb) | (g3 & b);
177 ctx->h4 = (ctx->h4 & nb) | (g4 & b);
179 /* FIXME: Take advantage of s being aligned as an unsigned long. */
180 f0 = ((ctx->h0 )|(ctx->h1<<26)) + (uint64_t)LE_READ_UINT32(s->b);
181 f1 = ((ctx->h1>> 6)|(ctx->h2<<20)) + (uint64_t)LE_READ_UINT32(s->b+4);
182 f2 = ((ctx->h2>>12)|(ctx->h3<<14)) + (uint64_t)LE_READ_UINT32(s->b+8);
183 f3 = ((ctx->h3>>18)|(ctx->h4<< 8)) + (uint64_t)LE_READ_UINT32(s->b+12);
185 LE_WRITE_UINT32(s->b, f0);
187 LE_WRITE_UINT32(s->b+4, f1);
189 LE_WRITE_UINT32(s->b+8, f2);
191 LE_WRITE_UINT32(s->b+12, f3);