| /* This Source Code Form is subject to the terms of the Mozilla Public |
| * License, v. 2.0. If a copy of the MPL was not distributed with this |
| * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ |
| |
| /* This implementation of poly1305 is by Andrew Moon |
| * (https://github.com/floodyberry/poly1305-donna) and released as public |
| * domain. */ |
| |
| #include <string.h> |
| |
| #include "poly1305.h" |
| |
| #if defined(_MSC_VER) && _MSC_VER < 1600 |
| #include "prtypes.h" |
| typedef PRUint32 uint32_t; |
| typedef PRUint64 uint64_t; |
| #else |
| #include <stdint.h> |
| #endif |
| |
| #if defined(NSS_X86) || defined(NSS_X64) |
| /* We can assume little-endian. */ |
| static uint32_t U8TO32_LE(const unsigned char *m) { |
| uint32_t r; |
| memcpy(&r, m, sizeof(r)); |
| return r; |
| } |
| |
| static void U32TO8_LE(unsigned char *m, uint32_t v) { |
| memcpy(m, &v, sizeof(v)); |
| } |
| #else |
| static uint32_t U8TO32_LE(const unsigned char *m) { |
| return (uint32_t)m[0] | |
| (uint32_t)m[1] << 8 | |
| (uint32_t)m[2] << 16 | |
| (uint32_t)m[3] << 24; |
| } |
| |
| static void U32TO8_LE(unsigned char *m, uint32_t v) { |
| m[0] = v; |
| m[1] = v >> 8; |
| m[2] = v >> 16; |
| m[3] = v >> 24; |
| } |
| #endif |
| |
| static uint64_t |
| mul32x32_64(uint32_t a, uint32_t b) { |
| return (uint64_t)a * b; |
| } |
| |
| struct poly1305_state_st { |
| uint32_t r0,r1,r2,r3,r4; |
| uint32_t s1,s2,s3,s4; |
| uint32_t h0,h1,h2,h3,h4; |
| unsigned char buf[16]; |
| unsigned int buf_used; |
| unsigned char key[16]; |
| }; |
| |
| /* update updates |state| given some amount of input data. This function may |
| * only be called with a |len| that is not a multiple of 16 at the end of the |
| * data. Otherwise the input must be buffered into 16 byte blocks. */ |
| static void update(struct poly1305_state_st *state, const unsigned char *in, |
| size_t len) { |
| uint32_t t0,t1,t2,t3; |
| uint64_t t[5]; |
| uint32_t b; |
| uint64_t c; |
| size_t j; |
| unsigned char mp[16]; |
| |
| if (len < 16) |
| goto poly1305_donna_atmost15bytes; |
| |
| poly1305_donna_16bytes: |
| t0 = U8TO32_LE(in); |
| t1 = U8TO32_LE(in+4); |
| t2 = U8TO32_LE(in+8); |
| t3 = U8TO32_LE(in+12); |
| |
| in += 16; |
| len -= 16; |
| |
| state->h0 += t0 & 0x3ffffff; |
| state->h1 += ((((uint64_t)t1 << 32) | t0) >> 26) & 0x3ffffff; |
| state->h2 += ((((uint64_t)t2 << 32) | t1) >> 20) & 0x3ffffff; |
| state->h3 += ((((uint64_t)t3 << 32) | t2) >> 14) & 0x3ffffff; |
| state->h4 += (t3 >> 8) | (1 << 24); |
| |
| poly1305_donna_mul: |
| t[0] = mul32x32_64(state->h0,state->r0) + |
| mul32x32_64(state->h1,state->s4) + |
| mul32x32_64(state->h2,state->s3) + |
| mul32x32_64(state->h3,state->s2) + |
| mul32x32_64(state->h4,state->s1); |
| t[1] = mul32x32_64(state->h0,state->r1) + |
| mul32x32_64(state->h1,state->r0) + |
| mul32x32_64(state->h2,state->s4) + |
| mul32x32_64(state->h3,state->s3) + |
| mul32x32_64(state->h4,state->s2); |
| t[2] = mul32x32_64(state->h0,state->r2) + |
| mul32x32_64(state->h1,state->r1) + |
| mul32x32_64(state->h2,state->r0) + |
| mul32x32_64(state->h3,state->s4) + |
| mul32x32_64(state->h4,state->s3); |
| t[3] = mul32x32_64(state->h0,state->r3) + |
| mul32x32_64(state->h1,state->r2) + |
| mul32x32_64(state->h2,state->r1) + |
| mul32x32_64(state->h3,state->r0) + |
| mul32x32_64(state->h4,state->s4); |
| t[4] = mul32x32_64(state->h0,state->r4) + |
| mul32x32_64(state->h1,state->r3) + |
| mul32x32_64(state->h2,state->r2) + |
| mul32x32_64(state->h3,state->r1) + |
| mul32x32_64(state->h4,state->r0); |
| |
| state->h0 = (uint32_t)t[0] & 0x3ffffff; c = (t[0] >> 26); |
| t[1] += c; state->h1 = (uint32_t)t[1] & 0x3ffffff; b = (uint32_t)(t[1] >> 26); |
| t[2] += b; state->h2 = (uint32_t)t[2] & 0x3ffffff; b = (uint32_t)(t[2] >> 26); |
| t[3] += b; state->h3 = (uint32_t)t[3] & 0x3ffffff; b = (uint32_t)(t[3] >> 26); |
| t[4] += b; state->h4 = (uint32_t)t[4] & 0x3ffffff; b = (uint32_t)(t[4] >> 26); |
| state->h0 += b * 5; |
| |
| if (len >= 16) |
| goto poly1305_donna_16bytes; |
| |
| /* final bytes */ |
| poly1305_donna_atmost15bytes: |
| if (!len) |
| return; |
| |
| for (j = 0; j < len; j++) |
| mp[j] = in[j]; |
| mp[j++] = 1; |
| for (; j < 16; j++) |
| mp[j] = 0; |
| len = 0; |
| |
| t0 = U8TO32_LE(mp+0); |
| t1 = U8TO32_LE(mp+4); |
| t2 = U8TO32_LE(mp+8); |
| t3 = U8TO32_LE(mp+12); |
| |
| state->h0 += t0 & 0x3ffffff; |
| state->h1 += ((((uint64_t)t1 << 32) | t0) >> 26) & 0x3ffffff; |
| state->h2 += ((((uint64_t)t2 << 32) | t1) >> 20) & 0x3ffffff; |
| state->h3 += ((((uint64_t)t3 << 32) | t2) >> 14) & 0x3ffffff; |
| state->h4 += (t3 >> 8); |
| |
| goto poly1305_donna_mul; |
| } |
| |
| void Poly1305Init(poly1305_state *statep, const unsigned char key[32]) { |
| struct poly1305_state_st *state = (struct poly1305_state_st*) statep; |
| uint32_t t0,t1,t2,t3; |
| |
| t0 = U8TO32_LE(key+0); |
| t1 = U8TO32_LE(key+4); |
| t2 = U8TO32_LE(key+8); |
| t3 = U8TO32_LE(key+12); |
| |
| /* precompute multipliers */ |
| state->r0 = t0 & 0x3ffffff; t0 >>= 26; t0 |= t1 << 6; |
| state->r1 = t0 & 0x3ffff03; t1 >>= 20; t1 |= t2 << 12; |
| state->r2 = t1 & 0x3ffc0ff; t2 >>= 14; t2 |= t3 << 18; |
| state->r3 = t2 & 0x3f03fff; t3 >>= 8; |
| state->r4 = t3 & 0x00fffff; |
| |
| state->s1 = state->r1 * 5; |
| state->s2 = state->r2 * 5; |
| state->s3 = state->r3 * 5; |
| state->s4 = state->r4 * 5; |
| |
| /* init state */ |
| state->h0 = 0; |
| state->h1 = 0; |
| state->h2 = 0; |
| state->h3 = 0; |
| state->h4 = 0; |
| |
| state->buf_used = 0; |
| memcpy(state->key, key + 16, sizeof(state->key)); |
| } |
| |
| void Poly1305Update(poly1305_state *statep, const unsigned char *in, |
| size_t in_len) { |
| unsigned int i; |
| struct poly1305_state_st *state = (struct poly1305_state_st*) statep; |
| |
| if (state->buf_used) { |
| unsigned int todo = 16 - state->buf_used; |
| if (todo > in_len) |
| todo = in_len; |
| for (i = 0; i < todo; i++) |
| state->buf[state->buf_used + i] = in[i]; |
| state->buf_used += todo; |
| in_len -= todo; |
| in += todo; |
| |
| if (state->buf_used == 16) { |
| update(state, state->buf, 16); |
| state->buf_used = 0; |
| } |
| } |
| |
| if (in_len >= 16) { |
| size_t todo = in_len & ~0xf; |
| update(state, in, todo); |
| in += todo; |
| in_len &= 0xf; |
| } |
| |
| if (in_len) { |
| for (i = 0; i < in_len; i++) |
| state->buf[i] = in[i]; |
| state->buf_used = in_len; |
| } |
| } |
| |
| void Poly1305Finish(poly1305_state *statep, unsigned char mac[16]) { |
| struct poly1305_state_st *state = (struct poly1305_state_st*) statep; |
| uint64_t f0,f1,f2,f3; |
| uint32_t g0,g1,g2,g3,g4; |
| uint32_t b, nb; |
| |
| if (state->buf_used) |
| update(state, state->buf, state->buf_used); |
| |
| b = state->h0 >> 26; state->h0 = state->h0 & 0x3ffffff; |
| state->h1 += b; b = state->h1 >> 26; state->h1 = state->h1 & 0x3ffffff; |
| state->h2 += b; b = state->h2 >> 26; state->h2 = state->h2 & 0x3ffffff; |
| state->h3 += b; b = state->h3 >> 26; state->h3 = state->h3 & 0x3ffffff; |
| state->h4 += b; b = state->h4 >> 26; state->h4 = state->h4 & 0x3ffffff; |
| state->h0 += b * 5; |
| |
| g0 = state->h0 + 5; b = g0 >> 26; g0 &= 0x3ffffff; |
| g1 = state->h1 + b; b = g1 >> 26; g1 &= 0x3ffffff; |
| g2 = state->h2 + b; b = g2 >> 26; g2 &= 0x3ffffff; |
| g3 = state->h3 + b; b = g3 >> 26; g3 &= 0x3ffffff; |
| g4 = state->h4 + b - (1 << 26); |
| |
| b = (g4 >> 31) - 1; |
| nb = ~b; |
| state->h0 = (state->h0 & nb) | (g0 & b); |
| state->h1 = (state->h1 & nb) | (g1 & b); |
| state->h2 = (state->h2 & nb) | (g2 & b); |
| state->h3 = (state->h3 & nb) | (g3 & b); |
| state->h4 = (state->h4 & nb) | (g4 & b); |
| |
| f0 = ((state->h0 ) | (state->h1 << 26)) + (uint64_t)U8TO32_LE(&state->key[0]); |
| f1 = ((state->h1 >> 6) | (state->h2 << 20)) + (uint64_t)U8TO32_LE(&state->key[4]); |
| f2 = ((state->h2 >> 12) | (state->h3 << 14)) + (uint64_t)U8TO32_LE(&state->key[8]); |
| f3 = ((state->h3 >> 18) | (state->h4 << 8)) + (uint64_t)U8TO32_LE(&state->key[12]); |
| |
| U32TO8_LE(&mac[ 0], (uint32_t)f0); f1 += (f0 >> 32); |
| U32TO8_LE(&mac[ 4], (uint32_t)f1); f2 += (f1 >> 32); |
| U32TO8_LE(&mac[ 8], (uint32_t)f2); f3 += (f2 >> 32); |
| U32TO8_LE(&mac[12], (uint32_t)f3); |
| } |