From 9188ea83c346fdc2f668178ae7538665a1b09c02 Mon Sep 17 00:00:00 2001
From: Michael Stahl <mstahl@redhat.com>
Date: Fri, 12 Jan 2018 16:58:00 +0100
Subject: tdf#114939 package,comphelper: Try both real SHA1 and StarOffice SHA1

... when importing ODF documents.

In CreatePackageEncryptionData(), add a 3rd SHA1 password hash,
PackageSHA1CorrectEncryptionKey, to EncryptionData.

Use it in ZipPackageStream::getDataStream(), which has 3 fall-backs
for SHA1 bugs now.

Also add a CorrectSHA1DigestContext, to be used together with
PackageSHA1CorrectEncryptionKey, and rename the existing one to
StarOfficeSHA1DigestContext, to be used together with the existing
2 PackageSHA1{UTF8,MS1252}EncryptionKey.

The fallback won't be used very often anyway: for the password SHA1
to be wrong, you need a password between 52 and 55 bytes long,
and for the SHA1/1K checksum to be wrong, you need a file
smaller than 1K with compressed size mod 64 between 52 and 55;
all XML files have enough random "chaff" added to be too large.

Test that we can read both correct SHA1 and StarOffice SHA1.

Change-Id: I988fa489b5e40c7657f404f18538f637d54d28f1
---
 comphelper/source/misc/storagehelper.cxx | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

(limited to 'comphelper')

diff --git a/comphelper/source/misc/storagehelper.cxx b/comphelper/source/misc/storagehelper.cxx
index de813848653b..dd52b7f6181a 100644
--- a/comphelper/source/misc/storagehelper.cxx
+++ b/comphelper/source/misc/storagehelper.cxx
@@ -50,6 +50,7 @@
 #include <ucbhelper/content.hxx>
 
 #include <comphelper/fileformat.h>
+#include <comphelper/hash.hxx>
 #include <comphelper/processfactory.hxx>
 #include <comphelper/documentconstants.hxx>
 #include <comphelper/storagehelper.hxx>
@@ -400,7 +401,8 @@ uno::Sequence< beans::NamedValue > OStorageHelper::CreatePackageEncryptionData(
         // MS_1252 encoding was used for SO60 document format password encoding,
         // this encoding supports only a minor subset of nonascii characters,
         // but for compatibility reasons it has to be used for old document formats
-        aEncryptionData.realloc( nSha1Ind + 2 );
+        aEncryptionData.realloc( nSha1Ind + 3 );
+        // these are StarOffice not-quite-SHA1
         aEncryptionData[nSha1Ind].Name = PACKAGE_ENCRYPTIONDATA_SHA1UTF8;
         aEncryptionData[nSha1Ind + 1].Name = PACKAGE_ENCRYPTIONDATA_SHA1MS1252;
 
@@ -424,6 +426,15 @@ uno::Sequence< beans::NamedValue > OStorageHelper::CreatePackageEncryptionData(
 
             aEncryptionData[nSha1Ind+nInd].Value <<= uno::Sequence< sal_Int8 >( reinterpret_cast<sal_Int8*>(pBuffer), RTL_DIGEST_LENGTH_SHA1 );
         }
+
+        // actual SHA1
+        aEncryptionData[nSha1Ind + 2].Name = PACKAGE_ENCRYPTIONDATA_SHA1CORRECT;
+        OString aByteStrPass = OUStringToOString(aPassword, RTL_TEXTENCODING_UTF8);
+        std::vector<unsigned char> const sha1(::comphelper::Hash::calculateHash(
+                reinterpret_cast<unsigned char const*>(aByteStrPass.getStr()), aByteStrPass.getLength(),
+                ::comphelper::HashType::SHA1));
+        aEncryptionData[nSha1Ind + 2].Value <<= uno::Sequence<sal_Int8>(
+                reinterpret_cast<sal_Int8 const*>(sha1.data()), sha1.size());
     }
 
     return aEncryptionData;
-- 
cgit