1*0957b409SSimon J. Gerraty /* 2*0957b409SSimon J. Gerraty * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org> 3*0957b409SSimon J. Gerraty * 4*0957b409SSimon J. Gerraty * Permission is hereby granted, free of charge, to any person obtaining 5*0957b409SSimon J. Gerraty * a copy of this software and associated documentation files (the 6*0957b409SSimon J. Gerraty * "Software"), to deal in the Software without restriction, including 7*0957b409SSimon J. Gerraty * without limitation the rights to use, copy, modify, merge, publish, 8*0957b409SSimon J. Gerraty * distribute, sublicense, and/or sell copies of the Software, and to 9*0957b409SSimon J. Gerraty * permit persons to whom the Software is furnished to do so, subject to 10*0957b409SSimon J. Gerraty * the following conditions: 11*0957b409SSimon J. Gerraty * 12*0957b409SSimon J. Gerraty * The above copyright notice and this permission notice shall be 13*0957b409SSimon J. Gerraty * included in all copies or substantial portions of the Software. 14*0957b409SSimon J. Gerraty * 15*0957b409SSimon J. Gerraty * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 16*0957b409SSimon J. Gerraty * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 17*0957b409SSimon J. Gerraty * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 18*0957b409SSimon J. Gerraty * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 19*0957b409SSimon J. Gerraty * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN 20*0957b409SSimon J. Gerraty * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 21*0957b409SSimon J. Gerraty * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 22*0957b409SSimon J. Gerraty * SOFTWARE. 23*0957b409SSimon J. Gerraty */ 24*0957b409SSimon J. Gerraty 25*0957b409SSimon J. Gerraty #include "inner.h" 26*0957b409SSimon J. Gerraty 27*0957b409SSimon J. Gerraty /* see inner.h */ 28*0957b409SSimon J. Gerraty void 29*0957b409SSimon J. Gerraty br_i32_encode(void *dst, size_t len, const uint32_t *x) 30*0957b409SSimon J. Gerraty { 31*0957b409SSimon J. Gerraty unsigned char *buf; 32*0957b409SSimon J. Gerraty size_t k; 33*0957b409SSimon J. Gerraty 34*0957b409SSimon J. Gerraty buf = dst; 35*0957b409SSimon J. Gerraty 36*0957b409SSimon J. Gerraty /* 37*0957b409SSimon J. Gerraty * Compute the announced size of x in bytes; extra bytes are 38*0957b409SSimon J. Gerraty * filled with zeros. 39*0957b409SSimon J. Gerraty */ 40*0957b409SSimon J. Gerraty k = (x[0] + 7) >> 3; 41*0957b409SSimon J. Gerraty while (len > k) { 42*0957b409SSimon J. Gerraty *buf ++ = 0; 43*0957b409SSimon J. Gerraty len --; 44*0957b409SSimon J. Gerraty } 45*0957b409SSimon J. Gerraty 46*0957b409SSimon J. Gerraty /* 47*0957b409SSimon J. Gerraty * Now we use k as index within x[]. That index starts at 1; 48*0957b409SSimon J. Gerraty * we initialize it to the topmost complete word, and process 49*0957b409SSimon J. Gerraty * any remaining incomplete word. 50*0957b409SSimon J. Gerraty */ 51*0957b409SSimon J. Gerraty k = (len + 3) >> 2; 52*0957b409SSimon J. Gerraty switch (len & 3) { 53*0957b409SSimon J. Gerraty case 3: 54*0957b409SSimon J. Gerraty *buf ++ = x[k] >> 16; 55*0957b409SSimon J. Gerraty /* fall through */ 56*0957b409SSimon J. Gerraty case 2: 57*0957b409SSimon J. Gerraty *buf ++ = x[k] >> 8; 58*0957b409SSimon J. Gerraty /* fall through */ 59*0957b409SSimon J. Gerraty case 1: 60*0957b409SSimon J. Gerraty *buf ++ = x[k]; 61*0957b409SSimon J. Gerraty k --; 62*0957b409SSimon J. Gerraty } 63*0957b409SSimon J. Gerraty 64*0957b409SSimon J. Gerraty /* 65*0957b409SSimon J. Gerraty * Encode all complete words. 66*0957b409SSimon J. Gerraty */ 67*0957b409SSimon J. Gerraty while (k > 0) { 68*0957b409SSimon J. Gerraty br_enc32be(buf, x[k]); 69*0957b409SSimon J. Gerraty k --; 70*0957b409SSimon J. Gerraty buf += 4; 71*0957b409SSimon J. Gerraty } 72*0957b409SSimon J. Gerraty } 73