From: Martin Willi <martin@revosec.ch>
Date: Fri, 17 Apr 2015 14:16:45 +0000 (+0200)
Subject: iv-gen: Fail getting shorter IV values than the used counter size
X-Git-Tag: 5.3.1~6
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ef31254d342d23cfbeb1b0030c9c6293545fca9d;p=thirdparty%2Fstrongswan.git

iv-gen: Fail getting shorter IV values than the used counter size

While no algorithm actually uses such short IVs, we add a check here to ensure
we won't return just the lower bits of the counter.
---

diff --git a/src/libstrongswan/crypto/iv/iv_gen_seq.c b/src/libstrongswan/crypto/iv/iv_gen_seq.c
index 70f1fce389..4de13744d9 100644
--- a/src/libstrongswan/crypto/iv/iv_gen_seq.c
+++ b/src/libstrongswan/crypto/iv/iv_gen_seq.c
@@ -53,6 +53,10 @@ METHOD(iv_gen_t, get_iv, bool,
 	{
 		return FALSE;
 	}
+	if (size < sizeof(u_int64_t))
+	{
+		return FALSE;
+	}
 	if (this->prev != SEQ_IV_INIT_STATE && seq <= this->prev)
 	{
 		return FALSE;