/* twister-small.c */

#include <stdint.h>
#include <string.h>
#include "memxor.h"
#include "twister-small.h"

static
void maxi_round3(twister_state_t* ctx, void* msg, uint8_t last_null){
	mini_round(ctx, msg);
	msg = ((uint8_t*)msg) + 8;
	mini_round(ctx, msg);
	if(last_null){
		blank_round(ctx);
	} else {
		msg = ((uint8_t*)msg) + 8;
		mini_round(ctx, msg);
	}
}

void twister_small_nextBlock(twister_state_t* ctx, void* msg){
	uint8_t tmp[8][8];
	/* round 1 */
	memcpy(tmp, ctx->s, 64);
	maxi_round3(ctx, msg, 0);
	memxor(ctx->s, tmp, 64);
	msg = ((uint8_t*)msg) + 3*8;
	/* round 2 */
	memcpy(tmp, ctx->s, 64);
	maxi_round3(ctx, msg, 0);
	memxor(ctx->s, tmp, 64);
	msg = ((uint8_t*)msg) + 3*8;
	/* round 3 */
	memcpy(tmp, ctx->s, 64);
	maxi_round3(ctx, msg, 1);
	memxor(ctx->s, tmp, 64);
	ctx->length_counter_b += 512;
}

void twister_small_init(twister_state_t* ctx, uint16_t hashsize_b){
	memset(ctx->s, 0, 64);
	ctx->counter=0xffffffffffffffffLL;
	ctx->s[0][7] = hashsize_b>>8;
	ctx->s[1][7] = hashsize_b&0xff;
	ctx->length_counter_b = 0;
}

void twister_small_lastBlock(twister_state_t* ctx, void* msg, uint16_t length_b){
	uint8_t tmp[64];	
	while(length_b>512){
		twister_small_nextBlock(ctx, msg);
		msg = ((uint8_t*)msg)+64;
		length_b -= 512;
	}
	memset(tmp, 0, 64);
	memcpy(tmp, msg, (length_b+7)/8);
	tmp[length_b/8] |= 0x80 >> (length_b&0x07);
	twister_small_nextBlock(ctx, tmp);
	ctx->length_counter_b -= 512 - length_b;
	mini_round(ctx, &(ctx->length_counter_b));
	blank_round(ctx);
}

void twister_small_ctx2hash(void* dest, twister_state_t* ctx, uint16_t hashsize_b){
	uint8_t tmp[8][8];
	uint8_t j;
	uint16_t i=hashsize_b;
	while(i>=64){
		i-=64;
		memcpy(tmp,ctx->s, 64);
		blank_round(ctx);
		memxor(ctx->s, tmp, 64);
		blank_round(ctx);
		for(j=0; j<8; ++j){
			*((uint8_t*)dest) = ctx->s[7-j][0] ^ tmp[7-j][0];
			dest = (uint8_t*)dest + 1;
		}
	}
	if(i>=32){
		memcpy(tmp,ctx->s, 64);
		blank_round(ctx);
		memxor(ctx->s, tmp, 64);
		blank_round(ctx);
		for(j=0; j<4; ++j){
			*((uint8_t*)dest) = ctx->s[3-j][0] ^ tmp[3-j][0];
			dest = (uint8_t*)dest + 1;
		}
	}
}

#ifndef NO_TWISTER_256

void twister256_init(twister256_ctx_t* ctx){
	twister_small_init(ctx, 256);
}

void twister256_nextBlock(twister256_ctx_t* ctx, void* msg){
	twister_small_nextBlock(ctx, msg);
}

void twister256_lastBlock(twister256_ctx_t* ctx, void* msg, uint16_t length_b){
	twister_small_lastBlock(ctx, msg, length_b);
}

void twister256_ctx2hash(void* dest, twister256_ctx_t* ctx){
	twister_small_ctx2hash(dest, ctx, 256);
}

void twister256(void* dest, void* msg, uint32_t msg_length_b){
	twister_state_t ctx;
	twister_small_init(&ctx, 256);
	while(msg_length_b >=512){
		twister_small_nextBlock(&ctx, msg);
		msg = (uint8_t*)msg + 512/8;
		msg_length_b -= 512;
	}
	twister_small_lastBlock(&ctx, msg, msg_length_b);
	twister_small_ctx2hash(dest, &ctx, 256);
}

#endif

#ifndef NO_TWISTER_224

void twister224_init(twister224_ctx_t* ctx){
	twister_small_init(ctx, 224);
}

void twister224_nextBlock(twister224_ctx_t* ctx, void* msg){
	twister_small_nextBlock(ctx, msg);
}

void twister224_lastBlock(twister224_ctx_t* ctx, void* msg, uint16_t length_b){
	twister_small_lastBlock(ctx, msg, length_b);
}

void twister224_ctx2hash(void* dest, twister224_ctx_t* ctx){
	twister_small_ctx2hash(dest, ctx, 224);
}

void twister224(void* dest, void* msg, uint32_t msg_length_b){
	twister_state_t ctx;
	twister_small_init(&ctx, 224);
	while(msg_length_b >=512){
		twister_small_nextBlock(&ctx, msg);
		msg = (uint8_t*)msg + 512/8;
		msg_length_b -= 512;
	}
	twister_small_lastBlock(&ctx, msg, msg_length_b);
	twister_small_ctx2hash(dest, &ctx, 224);
}

#endif