optimized xtea asm implementation

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

diff --git a/arcfour/arcfour.c b/arcfour/arcfour.c
index 0d929efa899edfeba59634a76688970cabcdbdb1..6c068a8023ee0acb487b33a313c050f6afa8e9b4 100644 (file)
--- a/arcfour/arcfour.c
+++ b/arcfour/arcfour.c
@@ -36,18 +36,24 @@
 void arcfour_init(const void *key, uint16_t length_b, arcfour_ctx_t *ctx){
        uint8_t t;
        uint8_t length_B = length_b/8;
-       uint16_t x,y=0;
-       for(x=0; x<= 255; ++x)
+       uint8_t x=0,y=0;
+       uint8_t *kptr=key;
+       do{
                ctx->s[x]=x;
+       }while(++x);
 
-       for(x=0; x<= 255; ++x){
-               y += ctx->s[x] + ((uint8_t*)key)[x % length_B];
+       do{
+               y += ctx->s[x] + *kptr++;
+               if(x==length_B){
+                       kptr = key;
+               }
                y &= 0xff;
                /* ctx->s[y] <--> ctx->s[x] */
                t = ctx->s[y];
                ctx->s[y] = ctx->s[x];
                ctx->s[x] = t;
-       }
+       }while(++x);
+
        ctx->i = ctx->j = 0;
 }