143 lines
3.6 KiB
C
143 lines
3.6 KiB
C
/* salsa20.c */
|
|
/*
|
|
This file is part of the ARM-Crypto-Lib.
|
|
Copyright (C) 2006-2011 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 <stdint.h>
|
|
#include <string.h>
|
|
#include "salsa20.h"
|
|
|
|
|
|
#define ROTL32(a,n) (((a)<<(n))|((a)>>(32-(n))))
|
|
|
|
static
|
|
void quaterround(uint32_t* a, uint32_t* b, uint32_t* c, uint32_t* d){
|
|
*b ^= ROTL32(*a + *d, 7);
|
|
*c ^= ROTL32(*b + *a, 9);
|
|
*d ^= ROTL32(*c + *b, 13);
|
|
*a ^= ROTL32(*d + *c, 18);
|
|
}
|
|
|
|
static
|
|
void rowround(uint32_t* a){
|
|
quaterround(a+ 0, a+ 1, a+ 2, a+ 3);
|
|
quaterround(a+ 5, a+ 6, a+ 7, a+ 4);
|
|
quaterround(a+10, a+11, a+ 8, a+ 9);
|
|
quaterround(a+15, a+12, a+13, a+14);
|
|
}
|
|
|
|
static
|
|
void columnround(uint32_t* a){
|
|
quaterround(a+ 0, a+ 4, a+ 8, a+12);
|
|
quaterround(a+ 5, a+ 9, a+13, a+ 1);
|
|
quaterround(a+10, a+14, a+ 2, a+ 6);
|
|
quaterround(a+15, a+ 3, a+ 7, a+11);
|
|
}
|
|
|
|
static
|
|
void doubleround(uint32_t* a){
|
|
columnround(a);
|
|
rowround(a);
|
|
|
|
}
|
|
|
|
|
|
void salsa20_hash(uint32_t* a){
|
|
uint8_t i;
|
|
uint32_t b[16];
|
|
memcpy(b, a, 64);
|
|
for(i=0; i<10; ++i){
|
|
doubleround(a);
|
|
}
|
|
for(i=0; i<16; ++i){
|
|
a[i] += b[i];
|
|
}
|
|
}
|
|
|
|
uint8_t sigma[] = {'e','x','p','a','n','d',' ','3','2','-','b','y','t','e',' ','k'};
|
|
uint8_t theta[] = {'e','x','p','a','n','d',' ','1','6','-','b','y','t','e',' ','k'};
|
|
|
|
void salsa_k32(uint32_t* dest, const uint32_t* k, const uint32_t* n){
|
|
memcpy(dest+ 0, sigma+ 0, 4);
|
|
memcpy(dest+ 4, k+ 0, 16);
|
|
memcpy(dest+20, sigma+ 4, 4);
|
|
memcpy(dest+24, n+ 0, 16);
|
|
memcpy(dest+40, sigma+ 8, 4);
|
|
memcpy(dest+44, k+16, 16);
|
|
memcpy(dest+60, sigma+12, 4);
|
|
salsa20_hash(dest);
|
|
}
|
|
|
|
void salsa_k16(uint32_t* dest, const uint32_t* k, const uint32_t* n){
|
|
memcpy(dest+ 0, theta+ 0, 4);
|
|
memcpy(dest+ 4, k+ 0, 16);
|
|
memcpy(dest+20, theta+ 4, 4);
|
|
memcpy(dest+24, n+ 0, 16);
|
|
memcpy(dest+40, theta+ 8, 4);
|
|
memcpy(dest+44, k+ 0, 16);
|
|
memcpy(dest+60, theta+12, 4);
|
|
salsa20_hash(dest);
|
|
}
|
|
|
|
void salsa20_genBlock256(void* dest, const void* k, const void* iv, uint64_t i){
|
|
uint32_t n[4];
|
|
memcpy(n, iv, 8);
|
|
//? memcpy(n+8, &i, 8);
|
|
salsa_k32((uint32_t*)dest, (uint32_t*)k, n);
|
|
}
|
|
|
|
void salsa20_genBlock128(void* dest, const void* k, const void* iv, uint64_t i){
|
|
uint32_t n[4];
|
|
memcpy(n, iv, 8);
|
|
//? memcpy(n+8, &i, 8);
|
|
salsa_k16((uint32_t*)dest, (uint32_t*)k, n);
|
|
}
|
|
|
|
|
|
void salsa20_init(void* key, uint16_t keylength_b, void* iv, salsa20_ctx_t* ctx){
|
|
if(keylength_b==256){
|
|
memcpy((ctx->a+ 0), sigma+ 0, 4);
|
|
memcpy((ctx->a+20), sigma+ 4, 4);
|
|
memcpy((ctx->a+40), sigma+ 8, 4);
|
|
memcpy((ctx->a+44), (uint8_t*)key+16, 16);
|
|
memcpy((ctx->a+60), sigma+12, 4);
|
|
}else{
|
|
memcpy((ctx->a+ 0), theta+ 0, 4);
|
|
memcpy((ctx->a+20), theta+ 4, 4);
|
|
memcpy((ctx->a+40), theta+ 8, 4);
|
|
memcpy((ctx->a+44), (uint8_t*)key+ 0, 16);
|
|
memcpy((ctx->a+60), theta+12, 4);
|
|
}
|
|
memcpy((ctx->a+ 4), key, 16);
|
|
memset((ctx->a+24), 0, 16);
|
|
if(iv){
|
|
memcpy((ctx->a+24), iv, 8);
|
|
}
|
|
ctx->buffer_idx=64;
|
|
}
|
|
|
|
uint8_t salsa20_gen(salsa20_ctx_t* ctx){
|
|
if(ctx->buffer_idx==64){
|
|
memcpy(ctx->buffer, ctx->a, 64);
|
|
salsa20_hash((uint32_t*)(ctx->buffer));
|
|
*((uint64_t*)(ctx->a+32)) += 1;
|
|
ctx->buffer_idx = 0;
|
|
}
|
|
return ctx->buffer[ctx->buffer_idx++];
|
|
}
|
|
|