From: Andre Noll <maan@systemlinux.org>
Date: Mon, 14 Mar 2011 16:25:14 +0000 (+0100)
Subject: Document RC4_ALIGN.
X-Git-Tag: v0.4.7~14^2
X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=commitdiff_plain;h=54cf5827;hp=ae7a5e56804fcb6789b5512201cacb6f29b2fb7b

Document RC4_ALIGN.

It's not obvious what is going on there, so add explain why we are doing
this ugly dance.
---

diff --git a/crypt.c b/crypt.c
index 9085f66b..8e1814dd 100644
--- a/crypt.c
+++ b/crypt.c
@@ -219,7 +219,6 @@ int pub_encrypt(struct asymmetric_key *pub, unsigned char *inbuf,
 	return ret < 0? -E_ENCRYPT : ret;
 }
 
-#define RC4_ALIGN 8
 struct stream_cipher {
 	RC4_KEY key;
 };
@@ -249,6 +248,13 @@ void sc_free(struct stream_cipher *sc)
 	free(sc);
 }
 
+/**
+ * The RC4() implementation of openssl apparently reads and writes data in
+ * blocks of 8 bytes. So we have to make sure our buffer sizes are a multiple
+ * of this.
+ */
+#define RC4_ALIGN 8
+
 /**
  * Encrypt and send a buffer.
  *