From b69e61c39868383b0d7819077db13d6be2d60c5f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Love=20H=C3=B6rnquist=20=C3=85strand?= <lha@kth.se>
Date: Tue, 5 Sep 2006 21:24:48 +0000
Subject: [PATCH] Check for Daniel Bleichenbacher an attack on PKCS #1 v1.5
 signatures.

git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@18029 ec53bebd-3082-4978-b11e-865c3cabbd6b
---
 lib/des/rsa-imath.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/lib/des/rsa-imath.c b/lib/des/rsa-imath.c
index 24243bfb2..6545c849f 100644
--- a/lib/des/rsa-imath.c
+++ b/lib/des/rsa-imath.c
@@ -188,6 +188,14 @@ imath_rsa_public_decrypt(int flen, const unsigned char* from,
 	return -1;
     size--; p++;
 
+    /* 
+     * Check for Daniel Bleichenbacher an attack on PKCS #1 v1.5
+     * signatures. Doesn't work on standard signatures and small key,
+     * so limit when we check for it.
+     */
+    if (size > 42 && (3 * 8 * size) >= BN_num_bits(rsa->n))
+	return -1;
+
     memmove(to, p, size);
 
     return size;