fixing a bug in threefish-256 decryption assembler module

[avr-crypto-lib.git] / threefish256_enc.c

diff --git a/threefish256_enc.c b/threefish256_enc.c
index 2739f6a3d88cfa941f9818a25abe335914995042..8bfbf9de471bad329a6490300d49c25f4e7358b0 100644 (file)
--- a/threefish256_enc.c
+++ b/threefish256_enc.c
@@ -46,13 +46,17 @@ void permute_4(void* data){
 
 void threefish256_init(const void* key, const void* tweak, threefish256_ctx_t* ctx){
        memcpy(ctx->k, key, 4*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->t, 0, 3*8);
+       }
        uint8_t i;
        ctx->k[4] = THREEFISH_KEY_CONST;
        for(i=0; i<4; ++i){
                ctx->k[4] ^= K(i);
        }
-       ctx->t[2] = T(0) ^ T(1);
 }
 
 static