GCM_AES_SALT_SIZE
memcpy(fctx->crypto.iv, areq->iv, GCM_AES_SALT_SIZE);
rctx->iv = &areq->iv[GCM_AES_SALT_SIZE];
rctx->ivsize = GCM_AES_IV_SIZE - GCM_AES_SALT_SIZE;
memcpy(fctx->crypto.iv, areq->iv, GCM_AES_SALT_SIZE);
rctx->iv = &areq->iv[GCM_AES_SALT_SIZE];
rctx->ivsize = GCM_AES_IV_SIZE - GCM_AES_SALT_SIZE;
if (keylen < GCM_AES_SALT_SIZE)
keylen -= GCM_AES_SALT_SIZE;
memcpy(fctx->crypto.iv, key + keylen, GCM_AES_SALT_SIZE);