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 bearssl_block.h */ 28*0957b409SSimon J. Gerraty void 29*0957b409SSimon J. Gerraty br_des_ct_cbcdec_init(br_des_ct_cbcdec_keys *ctx, 30*0957b409SSimon J. Gerraty const void *key, size_t len) 31*0957b409SSimon J. Gerraty { 32*0957b409SSimon J. Gerraty ctx->vtable = &br_des_ct_cbcdec_vtable; 33*0957b409SSimon J. Gerraty ctx->num_rounds = br_des_ct_keysched(ctx->skey, key, len); 34*0957b409SSimon J. Gerraty if (len == 8) { 35*0957b409SSimon J. Gerraty br_des_rev_skey(ctx->skey); 36*0957b409SSimon J. Gerraty } else { 37*0957b409SSimon J. Gerraty int i; 38*0957b409SSimon J. Gerraty 39*0957b409SSimon J. Gerraty for (i = 0; i < 48; i += 2) { 40*0957b409SSimon J. Gerraty uint32_t t; 41*0957b409SSimon J. Gerraty 42*0957b409SSimon J. Gerraty t = ctx->skey[i]; 43*0957b409SSimon J. Gerraty ctx->skey[i] = ctx->skey[94 - i]; 44*0957b409SSimon J. Gerraty ctx->skey[94 - i] = t; 45*0957b409SSimon J. Gerraty t = ctx->skey[i + 1]; 46*0957b409SSimon J. Gerraty ctx->skey[i + 1] = ctx->skey[95 - i]; 47*0957b409SSimon J. Gerraty ctx->skey[95 - i] = t; 48*0957b409SSimon J. Gerraty } 49*0957b409SSimon J. Gerraty } 50*0957b409SSimon J. Gerraty } 51*0957b409SSimon J. Gerraty 52*0957b409SSimon J. Gerraty /* see bearssl_block.h */ 53*0957b409SSimon J. Gerraty void 54*0957b409SSimon J. Gerraty br_des_ct_cbcdec_run(const br_des_ct_cbcdec_keys *ctx, 55*0957b409SSimon J. Gerraty void *iv, void *data, size_t len) 56*0957b409SSimon J. Gerraty { 57*0957b409SSimon J. Gerraty unsigned char *buf, *ivbuf; 58*0957b409SSimon J. Gerraty uint32_t sk_exp[288]; 59*0957b409SSimon J. Gerraty 60*0957b409SSimon J. Gerraty br_des_ct_skey_expand(sk_exp, ctx->num_rounds, ctx->skey); 61*0957b409SSimon J. Gerraty ivbuf = iv; 62*0957b409SSimon J. Gerraty buf = data; 63*0957b409SSimon J. Gerraty while (len > 0) { 64*0957b409SSimon J. Gerraty unsigned char tmp[8]; 65*0957b409SSimon J. Gerraty int i; 66*0957b409SSimon J. Gerraty 67*0957b409SSimon J. Gerraty memcpy(tmp, buf, 8); 68*0957b409SSimon J. Gerraty br_des_ct_process_block(ctx->num_rounds, sk_exp, buf); 69*0957b409SSimon J. Gerraty for (i = 0; i < 8; i ++) { 70*0957b409SSimon J. Gerraty buf[i] ^= ivbuf[i]; 71*0957b409SSimon J. Gerraty } 72*0957b409SSimon J. Gerraty memcpy(ivbuf, tmp, 8); 73*0957b409SSimon J. Gerraty buf += 8; 74*0957b409SSimon J. Gerraty len -= 8; 75*0957b409SSimon J. Gerraty } 76*0957b409SSimon J. Gerraty } 77*0957b409SSimon J. Gerraty 78*0957b409SSimon J. Gerraty /* see bearssl_block.h */ 79*0957b409SSimon J. Gerraty const br_block_cbcdec_class br_des_ct_cbcdec_vtable = { 80*0957b409SSimon J. Gerraty sizeof(br_des_ct_cbcdec_keys), 81*0957b409SSimon J. Gerraty 8, 82*0957b409SSimon J. Gerraty 3, 83*0957b409SSimon J. Gerraty (void (*)(const br_block_cbcdec_class **, const void *, size_t)) 84*0957b409SSimon J. Gerraty &br_des_ct_cbcdec_init, 85*0957b409SSimon J. Gerraty (void (*)(const br_block_cbcdec_class *const *, void *, void *, size_t)) 86*0957b409SSimon J. Gerraty &br_des_ct_cbcdec_run 87*0957b409SSimon J. Gerraty }; 88