X-Git-Url: https://git.cryptolib.org/?a=blobdiff_plain;f=serpent.c;h=85cf4a852e4a731d46fc63e3baf852deeb5acd05;hb=8537c7a0647b533f078af9c35bce533335c7556e;hp=b2773fc220bb53cc172972d92592a7cb233f037a;hpb=64eeaf729bb29d0ca05fee5292652e8270335801;p=avr-crypto-lib.git

diff --git a/serpent.c b/serpent.c
index b2773fc..85cf4a8 100644
--- a/serpent.c
+++ b/serpent.c
@@ -170,10 +170,18 @@ static uint32_t gen_w(uint32_t * b, uint8_t i){
 } 
 
 /* key must be 256bit (32 byte) large! */
-void serpent_genctx(void * key, serpent_ctx_t * ctx){
+void serpent_genctx(void * key, uint8_t keysize, serpent_ctx_t * ctx){
 	uint32_t buffer[8];
 	uint8_t i,j;
-	memcpy(buffer, key, 32); 
+	if(keysize){
+		/* keysize is less than 256 bit, padding needed */
+		memset(buffer, 0, 32);
+		memcpy(buffer, key, (keysize+7)/8);
+		((uint8_t*)buffer)[keysize/8] |= 1<<(keysize%8);
+	} else {
+		/* keysize is 256 bit */
+		memcpy(buffer, key, 32); 
+	}
 	for(i=0; i<33; ++i){
 		for(j=0; j<4; ++j){
 			ctx->k[i][j] = gen_w(buffer, i*4+j);