uint8_t bcal_eax_init(const bcdesc_t *desc, const void *key, uint16_t keysize_b, bcal_eax_ctx_t *ctx){
uint8_t r;
ctx->blocksize_B = (bcal_cipher_getBlocksize_b(desc)+7)/8;
ctx->nonce = malloc(ctx->blocksize_B);
if(ctx->nonce==NULL){
return 0x81;
}
r = bcal_cmac_init(desc, key, keysize_b, &(ctx->ctag));
if(r){
return r;
}
r = bcal_cmac_init(desc, key, keysize_b, &(ctx->htag));
if(r){
return (r|0x10);
}
r = bcal_cmac_init(desc, key, keysize_b, &(ctx->ntag));
if(r){
return (r|0x20);
}
r = bcal_ctr_init(desc, key, keysize_b, NULL, &(ctx->cipher));
if(r){
return (r|0x30);
}
ctx->header_set=0;
uint8_t tmp[ctx->blocksize_B];
memset(tmp, 0, ctx->blocksize_B);
bcal_cmac_nextBlock(&(ctx->ntag), tmp);
tmp[ctx->blocksize_B-1]=1;
bcal_cmac_nextBlock(&(ctx->htag), tmp);
tmp[ctx->blocksize_B-1]=2;
bcal_cmac_nextBlock(&(ctx->ctag), tmp);
return 0;
}
uint8_t bcal_ofb_init(const bcdesc_t* desc, const void* key, uint16_t keysize_b, bcal_ofb_ctx_t* ctx){
ctx->desc = (bcdesc_t*)desc;
ctx->blocksize_B = (bcal_cipher_getBlocksize_b(desc)+7)/8;
ctx->in_block=malloc(ctx->blocksize_B);
if(ctx->in_block==NULL){
return 0x11;
}
return bcal_cipher_init(desc, key, keysize_b, &(ctx->cctx));
}
uint8_t bcal_ctr_init(const bcdesc_t* desc, const void* key, uint16_t keysize_b, inc_fp_t inc_func, bcal_ctr_ctx_t* ctx){
ctx->desc = (bcdesc_t*)desc;
if(inc_func){
ctx->inc_func = inc_func;
}else{
ctx->inc_func = increment_be;
}
ctx->blocksize_B = (bcal_cipher_getBlocksize_b(desc)+7)/8;
ctx->in_block=malloc(ctx->blocksize_B);
if(ctx->in_block==NULL){
return 0x11;
}
return bcal_cipher_init(desc, key, keysize_b, &(ctx->cctx));
}
uint8_t bcal_cmac_init(const bcdesc_t *desc, const void *key,
uint16_t keysize_b, bcal_cmac_ctx_t *ctx)
{
uint8_t r;
ctx->desc = (bcdesc_t*) desc;
ctx->blocksize_B = bcal_cipher_getBlocksize_b(desc) / 8;
if (ctx->blocksize_B != 128 / 8 && ctx->blocksize_B != 64 / 8) {
return 0x13;
}
ctx->accu = malloc(ctx->blocksize_B);
if (ctx->accu == NULL) {
return 0x14;
}
ctx->k1 = malloc(ctx->blocksize_B);
if (ctx->k1 == NULL) {
return 0x15;
}
ctx->k2 = malloc(ctx->blocksize_B);
if (ctx->k2 == NULL) {
return 0x16;
}
ctx->lastblock = malloc(ctx->blocksize_B);
if (ctx->lastblock == NULL) {
return 0x17;
}
r = bcal_cipher_init(desc, key, keysize_b, &(ctx->cctx));
if (r) {
return r;
}
if (ctx->blocksize_B == 128 / 8) {
r = const_128;
} else {
r = const_64;
}
/* subkey computation */
memset(ctx->accu, 0x00, ctx->blocksize_B);
memset(ctx->k1, 0x00, ctx->blocksize_B);
bcal_cipher_enc(ctx->k1, &(ctx->cctx));
if (left_shift_be_block(ctx->k1, ctx->blocksize_B)) {
ctx->k1[ctx->blocksize_B - 1] ^= r;
}
memcpy(ctx->k2, ctx->k1, ctx->blocksize_B);
if (left_shift_be_block(ctx->k2, ctx->blocksize_B)) {
ctx->k2[ctx->blocksize_B - 1] ^= r;
}
ctx->last_set = 0;
return 0;
}