/* * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org> * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation the rights to use, copy, modify, merge, publish, * distribute, sublicense, and/or sell copies of the Software, and to * permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. */ #include "inner.h" /* see bearssl_block.h */ void br_des_tab_cbcdec_init(br_des_tab_cbcdec_keys *ctx, const void *key, size_t len) { ctx->vtable = &br_des_tab_cbcdec_vtable; ctx->num_rounds = br_des_tab_keysched(ctx->skey, key, len); if (len == 8) { br_des_rev_skey(ctx->skey); } else { int i; for (i = 0; i < 48; i += 2) { uint32_t t; t = ctx->skey[i]; ctx->skey[i] = ctx->skey[94 - i]; ctx->skey[94 - i] = t; t = ctx->skey[i + 1]; ctx->skey[i + 1] = ctx->skey[95 - i]; ctx->skey[95 - i] = t; } } } /* see bearssl_block.h */ void br_des_tab_cbcdec_run(const br_des_tab_cbcdec_keys *ctx, void *iv, void *data, size_t len) { unsigned char *buf, *ivbuf; ivbuf = iv; buf = data; while (len > 0) { unsigned char tmp[8]; int i; memcpy(tmp, buf, 8); br_des_tab_process_block(ctx->num_rounds, ctx->skey, buf); for (i = 0; i < 8; i ++) { buf[i] ^= ivbuf[i]; } memcpy(ivbuf, tmp, 8); buf += 8; len -= 8; } } /* see bearssl_block.h */ const br_block_cbcdec_class br_des_tab_cbcdec_vtable = { sizeof(br_des_tab_cbcdec_keys), 8, 3, (void (*)(const br_block_cbcdec_class **, const void *, size_t)) &br_des_tab_cbcdec_init, (void (*)(const br_block_cbcdec_class *const *, void *, void *, size_t)) &br_des_tab_cbcdec_run };