This patch aligns the structure describing the RSA signature
option to 8 bytes. Before that, send was padding with N bytes
(4 on 32-bits architectures) using a cast in sendd/proto_sig.c :

	so = (struct snd_opt_sig *)(nd_so);

which would align to the number of bytes representing a pointer
on your architecture.

Index: sendd-0.2/sendd/snd_proto.h
============================================================
--- sendd-0.2/sendd/snd_proto.h	2008-04-18 16:21:46.000000000 +0200
+++ sendd-0.2.new/sendd/snd_proto.h	2008-10-05 16:08:34.000000000 +0200
@@ -69,7 +69,7 @@
 	uint32_t		reserved;	/* opt hdr + reserved */
 	uint8_t			keyhash[SND_KEYHASH_LEN];
 	uint8_t			sig[0];
-};
+} __attribute__((aligned(8)));
 
 struct snd_opt_timestamp {
 	uint8_t			type;
