X-Git-Url: https://git.cryptolib.org/?p=avr-crypto-lib.git;a=blobdiff_plain;f=arcfour%2Farcfour-asm.S;h=a7f5a88b22f9ed804838036eff2247093f243559;hp=1ef8218ce971a608ffaf096959dc40fb63141804;hb=4b5da1dc27a791b5c448274a3db09cd035b33493;hpb=d32eba56ce10ea6b9eff123b50d9842673b38f2b

diff --git a/arcfour/arcfour-asm.S b/arcfour/arcfour-asm.S
index 1ef8218..a7f5a88 100644
--- a/arcfour/arcfour-asm.S
+++ b/arcfour/arcfour-asm.S
@@ -1,7 +1,7 @@
 /* arcfour-asm.S */
 /*
     This file is part of the AVR-Crypto-Lib.
-    Copyright (C) 2008  Daniel Otte (daniel.otte@rub.de)
+    Copyright (C) 2006-2015 Daniel Otte (bg@nerilex.org)
 
     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
@@ -40,8 +40,8 @@
  *  this function initialises the context
  * param1: 16-bit pointer to the key
  *	given in r24:r25
- * param2: 8-bit integer indicating keylength in byte
- *	given in r22
+ * param2: 8-bit integer indicating keylength in bits
+ *	given in r22:r23
  * param3: 16-bit pointer to a ctx struct
  *	given in r20:r21
  */
@@ -52,7 +52,12 @@ arcfour_init:
 	st X+, r1
 	st X+, r1       /* X points to S */
 	movw r20, r26   /* store pointer to S in r21:r20 */
-	
+	lsr r23
+	ror r22
+	lsr r23
+	ror r22
+	lsr r23
+	ror r22
 1:		
 	st X+, r1 
 	inc r1
@@ -96,7 +101,7 @@ uint8_t arcfour_gen(arcfour_ctx_t *c){
 .global arcfour_gen
 
 ;== arcfour_gen ==
-;  this function initialises the context
+; this function generates a keystream byte
 ; param1: 16-bit pointer to a ctx struct
 ;	given in r25,r24
 
@@ -114,7 +119,7 @@ arcfour_gen:
 	st Z+, r19		/* i,j loaded&saved; X->S[i]; Z->S[0]; r20=S[i] */
 	add r30, r19
 	adc r31, r1
-	ld r21, Z		/* X->S[i]; Z->S[j]; r20=S[i]; r21=S[j]*/
+	ld r21, Z		/* X->S[i]; Z->S[j]; r20=S[i]; r21=S[j] */
 	st Z, r20
 	st X, r21
 	add r20, r21