| 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 |
| |
