/*
- * Copyright (C) 2005-2012 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2005-2013 Andre Noll <maan@systemlinux.org>
*
* Licensed under the GPL v2. For licencing details see COPYING.
*/
void sc_crypt(struct stream_cipher *sc, struct iovec *src, struct iovec *dst)
{
+ size_t len = src->iov_len, l1, l2;
RC4_KEY *key = &sc->key;
+ assert(len > 0);
+ assert(len < ((typeof(src->iov_len))-1) / 2);
+ l1 = ROUND_DOWN(len, RC4_ALIGN);
+ l2 = ROUND_UP(len, RC4_ALIGN);
+
*dst = (typeof(*dst)) {
- /*
- * Add one for the terminating zero byte. Integer overflow is
- * no problem here as para_malloc() aborts when given a zero
- * size argument.
- */
- .iov_base = para_malloc(src->iov_len + 1),
- .iov_len = src->iov_len
+ /* Add one for the terminating zero byte. */
+ .iov_base = para_malloc(l2 + 1),
+ .iov_len = len
};
- RC4(key, src->iov_len, src->iov_base, dst->iov_base);
- ((char *)dst->iov_base)[dst->iov_len] = '\0';
+ RC4(key, l1, src->iov_base, dst->iov_base);
+ if (len > l1) {
+ unsigned char remainder[RC4_ALIGN] = "";
+ memcpy(remainder, src->iov_base + l1, len - l1);
+ RC4(key, len - l1, remainder, dst->iov_base + l1);
+ }
+ ((char *)dst->iov_base)[len] = '\0';
}
void hash_function(const char *data, unsigned long len, unsigned char *hash)