#define K(s) (((uint64_t*)key)[(s)])
#define T(s) (((uint64_t*)tweak)[(s)])
-void threefish1024_init(void* key, void* tweak, threefish1024_ctx_t* ctx){
+void threefish1024_init(const void* key, const void* tweak, threefish1024_ctx_t* ctx){
memcpy(ctx->k, key, 16*8);
- memcpy(ctx->t, tweak, 2*8);
+ if(tweak){
+ memcpy(ctx->t, tweak, 2*8);
+ ctx->t[2] = T(0) ^ T(1);
+ }else{
+ memset(ctx, 0, 3*8);
+ }
uint8_t i;
ctx->k[16] = THREEFISH_KEY_CONST;
for(i=0; i<16; ++i){
ctx->k[16] ^= K(i);
}
- ctx->t[2] = T(0) ^ T(1);
}
static
-void add_key_16(void* data, threefish1024_ctx_t* ctx, uint8_t s){
+void add_key_16(void* data, const threefish1024_ctx_t* ctx, uint8_t s){
uint8_t i;
for(i=0; i<13; ++i){
X(i) += ctx->k[(s+i)%17];
X(15) += ctx->k[(s+15)%17] + s;
}
-void threefish1024_enc(void* data, threefish1024_ctx_t* ctx){
+void threefish1024_enc(void* data, const threefish1024_ctx_t* ctx){
uint8_t i=0,s=0;
uint8_t r0[8] = {55, 25, 33, 34, 28, 17, 58, 47};
uint8_t r1[8] = {43, 25, 8, 43, 7, 6, 7, 49};