From: Gergely Nagy <ngg@tresorit.com>
Date: Wed, 14 Dec 2016 12:19:01 +0000 (+0100)
Subject: [PATCH] Fix possible DoS in ASN.1 decoders (CVE-2016-9939)
X-Git-Tag: archive/raspbian/8.7.0+git220824-1+rpi1~1^2^2^2^2~2
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=220caa8f1c66897aaf2e11a76cdb579e13c3e058;p=libcrypto%2B%2B.git

[PATCH] Fix possible DoS in ASN.1 decoders (CVE-2016-9939)


Gbp-Pq: Name CVE-2016-9939.patch
---

diff --git a/asn.cpp b/asn.cpp
index 13cd50c..0017f28 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 8c8ac32..adb677d 100644
--- a/asn.h
+++ b/asn.h
@@ -486,6 +486,8 @@ 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);