From 3d9181d7bdd8e491f745dbc9e34bd20b6f6da069 Mon Sep 17 00:00:00 2001
|
From: Gergely Nagy <ngg@tresorit.com>
|
Date: Wed, 14 Dec 2016 13:19:01 +0100
|
Subject: [PATCH] Fix possible DoS in ASN.1 decoders (CVE-2016-9939)
|
|
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
|
---
|
asn.cpp | 10 ++++++++++
|
asn.h | 2 ++
|
2 files changed, 12 insertions(+)
|
|
diff --git a/asn.cpp b/asn.cpp
|
index 297ff01..2e923ef 100644
|
--- a/asn.cpp
|
+++ b/asn.cpp
|
@@ -123,6 +123,8 @@ size_t BERDecodeOctetString(BufferedTransformation &bt, SecByteBlock &str)
|
size_t bc;
|
if (!BERLengthDecode(bt, bc))
|
BERDecodeError();
|
+ if (bc > bt.MaxRetrievable())
|
+ BERDecodeError();
|
|
str.New(bc);
|
if (bc != bt.Get(str, bc))
|
@@ -139,6 +141,8 @@ size_t BERDecodeOctetString(BufferedTransformation &bt, BufferedTransformation &
|
size_t bc;
|
if (!BERLengthDecode(bt, bc))
|
BERDecodeError();
|
+ if (bc > bt.MaxRetrievable())
|
+ BERDecodeError();
|
|
bt.TransferTo(str, bc);
|
return bc;
|
@@ -161,6 +165,8 @@ size_t BERDecodeTextString(BufferedTransformation &bt, std::string &str, byte as
|
size_t bc;
|
if (!BERLengthDecode(bt, bc))
|
BERDecodeError();
|
+ if (bc > bt.MaxRetrievable())
|
+ BERDecodeError();
|
|
SecByteBlock temp(bc);
|
if (bc != bt.Get(temp, bc))
|
@@ -188,6 +194,10 @@ size_t BERDecodeBitString(BufferedTransformation &bt, SecByteBlock &str, unsigne
|
size_t bc;
|
if (!BERLengthDecode(bt, bc))
|
BERDecodeError();
|
+ if (bc == 0)
|
+ BERDecodeError();
|
+ if (bc > bt.MaxRetrievable())
|
+ BERDecodeError();
|
|
byte unused;
|
if (!bt.Get(unused))
|
diff --git a/asn.h b/asn.h
|
index ed9de52..33f0dd0 100644
|
--- a/asn.h
|
+++ b/asn.h
|
@@ -498,6 +498,8 @@ void BERDecodeUnsigned(BufferedTransformation &in, T &w, byte asnTag = INTEGER,
|
bool definite = BERLengthDecode(in, bc);
|
if (!definite)
|
BERDecodeError();
|
+ if (bc > in.MaxRetrievable())
|
+ BERDecodeError();
|
|
SecByteBlock buf(bc);
|
|
--
|
2.10.2
|
