first lines of a blockcipher abstraction layer

[avr-crypto-lib.git] / bcal-basic.c

diff --git a/bcal-basic.c b/bcal-basic.c
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+++ b/bcal-basic.c
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+/* bcal-basic.c */
+/*
+    This file is part of the Crypto-avr-lib/microcrypt-lib.
+    Copyright (C) 2009  Daniel Otte (daniel.otte@rub.de)
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include "blockcipher_descriptor.h"
+#include "keysize_descriptor.h"
+
+
+uint8_t bcal_cipher_init(const bcdesc_t* cipher_descriptor,
+                         const void* key, uint16_t keysize, bcgen_ctx_t* ctx){
+       if(!is_valid_keysize_P((PGM_VOID_P)(pgm_read_word(cipher_descriptor->valid_keysize_desc)),
+                              keysize))
+               return 1;
+               
+       uint8_t flags;
+       bc_init_fpt init_fpt;
+       ctx->desc_ptr = (bcdesc_t*)cipher_descriptor;
+       ctx->keysize  = keysize;
+       flags = pgm_read_byte(cipher_descriptor->flags);
+       init_fpt.initvoid = (void_fpt)(pgm_read_word(cipher_descriptor->init.initvoid));
+       if(init_fpt.initvoid == NULL){
+               if(!(ctx->ctx = malloc(keysize/8)))
+                       return 2;
+               memcpy(ctx->ctx, key, keysize/8);
+               return 0;
+       }
+       if(!(ctx->ctx = malloc(pgm_read_word(cipher_descriptor->ctxsize_B))))
+               return 3;
+       if((flags&BC_INIT_TYPE)==BC_INIT_TYPE_1){
+               init_fpt.init1((void*)key, ctx->ctx);
+       }else{
+               init_fpt.init2((void*)key, keysize, ctx->ctx);
+       }
+       return 0;
+}
+
+void bcal_cipher_free(bcgen_ctx_t* ctx){
+       if(!ctx)
+               return;
+       bc_free_fpt free_fpt;
+       free_fpt = (bc_free_fpt)(pgm_read_word(ctx->desc_ptr->free));
+       if(free_fpt)
+               free_fpt(ctx->ctx);
+       free(ctx->ctx);
+}
+
+void bcal_cipher_enc(void* block, const bcgen_ctx_t* ctx){
+       uint8_t flags;
+       bc_enc_fpt enc_fpt;
+       flags = pgm_read_byte(ctx->desc_ptr->flags);
+       enc_fpt.encvoid = (void_fpt)pgm_read_word(ctx->desc_ptr->enc.encvoid);
+       if(!enc_fpt.encvoid){
+               /* very bad error, no enciphering function specified */
+               return;
+       }
+       if((flags&BC_ENC_TYPE)==BC_ENC_TYPE_1){
+               enc_fpt.enc1(block, ctx->ctx);
+       }else{
+               enc_fpt.enc2(block, block, ctx->ctx);
+       }
+}
+
+void bcal_cipher_dec(void* block, const bcgen_ctx_t* ctx){
+       uint8_t flags;
+       bc_dec_fpt dec_fpt;
+       flags = pgm_read_byte(ctx->desc_ptr->flags);
+       dec_fpt.decvoid = (void_fpt)pgm_read_word(ctx->desc_ptr->dec.decvoid);
+       if(!dec_fpt.decvoid){
+               /* very bad error, no deciphering function specified */
+               return;
+       }
+       if((flags&BC_DEC_TYPE)==BC_DEC_TYPE_1){
+               dec_fpt.dec1(block, ctx->ctx);
+       }else{
+               dec_fpt.dec2(block, block, ctx->ctx);
+       }
+}
+
+
+