From b24984deb36300de38e2191d58ce368422c68183 Mon Sep 17 00:00:00 2001
From: Matt Johnston <matt@ucc.asn.au>
Date: Sun, 4 Jan 2015 23:10:59 +0800
Subject: [PATCH] clear hash state memory after use

---
 common-kex.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/common-kex.c b/common-kex.c
index f5119d2f..65746a20 100644
--- a/common-kex.c
+++ b/common-kex.c
@@ -303,7 +303,7 @@ static void hashkeys(unsigned char *out, unsigned int outlen,
 		hash_desc->done(&hs2, tmpout);
 		memcpy(&out[offset], tmpout, MIN(outlen - offset, hash_desc->hashsize));
 	}
-
+	m_burn(&hs2, sizeof(hash_state));
 }
 
 /* Generate the actual encryption/integrity keys, using the results of the
@@ -403,6 +403,7 @@ static void gen_new_keys() {
 	m_burn(C2S_key, sizeof(C2S_key));
 	m_burn(S2C_IV, sizeof(S2C_IV));
 	m_burn(S2C_key, sizeof(S2C_key));
+	m_burn(&hs, sizeof(hash_state));
 
 	TRACE(("leave gen_new_keys"))
 }
@@ -798,6 +799,7 @@ static void finish_kexhashbuf(void) {
 
 	buf_burn(ses.kexhashbuf);
 	buf_free(ses.kexhashbuf);
+	m_burn(&hs, sizeof(hash_state));
 	ses.kexhashbuf = NULL;
 	
 	/* first time around, we set the session_id to H */
@@ -805,7 +807,6 @@ static void finish_kexhashbuf(void) {
 		/* create the session_id, this never needs freeing */
 		ses.session_id = buf_newcopy(ses.hash);
 	}
-
 }
 
 /* read the other side's algo list. buf_match_algo is a callback to match
-- 
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