split MSCodec_Std97 into a baseclass MSCodec97

Change-Id: Ia3c41a048169c78684800def94e53fc9f3201e30

1 files changed, 99 insertions, 55 deletions

diff --git a/include/filter/msfilter/mscodec.hxx b/include/filter/msfilter/mscodec.hxx
index fa71a1542a29..afdf163b747b 100644
--- a/include/filter/msfilter/mscodec.hxx
+++ b/include/filter/msfilter/mscodec.hxx
@@ -174,18 +174,11 @@ public:
     virtual void                Decode( sal_uInt8* pnData, std::size_t nBytes ) override;
 };
 
-
-/** Encodes and decodes data from protected MSO 97+ documents.
-
-    This is a wrapper class around low level cryptographic functions from RTL.
-    Implementation is based on the wvDecrypt package by Caolan McNamara:
-    http://www.csn.ul.ie/~caolan/docs/wvDecrypt.html
- */
-class MSFILTER_DLLPUBLIC MSCodec_Std97
+class MSFILTER_DLLPUBLIC MSCodec97
 {
 public:
-    explicit            MSCodec_Std97();
-                        ~MSCodec_Std97();
+    MSCodec97(rtlCipher m_hCipher);
+    virtual ~MSCodec97();
 
     /** Initializes the algorithm with the encryption data.
 
@@ -193,7 +186,7 @@ public:
             The sequence contains the necessary data to initialize
             the codec.
      */
-    bool                InitCodec( const css::uno::Sequence< css::beans::NamedValue >& aData );
+    virtual bool InitCodec(const css::uno::Sequence< css::beans::NamedValue >& aData) = 0;
 
     /** Retrieves the encryption data
 
@@ -201,38 +194,8 @@ public:
             The sequence contains the necessary data to initialize
             the codec.
      */
-    css::uno::Sequence< css::beans::NamedValue > GetEncryptionData();
-
-
-    /** Initializes the algorithm with the specified password and document ID.
-
-        @param pPassData
-            Wide character array containing the password. Must be zero
-            terminated, which results in a maximum length of 15 characters.
-        @param pDocId
-            Unique document identifier read from or written to the file.
-     */
-    void                InitKey(
-                            const sal_uInt16 pPassData[ 16 ],
-                            const sal_uInt8 pDocId[ 16 ] );
-
-    /** Verifies the validity of the password using the passed salt data.
-
-        @precond
-            The codec must be initialized with InitKey() before this function
-            can be used.
-
-        @param pSaltData
-            Salt data block read from the file.
-        @param pSaltDigest
-            Salt digest read from the file.
+    virtual css::uno::Sequence< css::beans::NamedValue > GetEncryptionData() = 0;
 
-        @return
-            true = Test was successful.
-     */
-    bool                VerifyKey(
-                            const sal_uInt8 pSaltData[ 16 ],
-                            const sal_uInt8 pSaltDigest[ 16 ] );
 
     /** Rekeys the codec using the specified counter.
 
@@ -249,11 +212,7 @@ public:
         @param nCounter
             Block counter used to rekey the cipher.
      */
-    bool                InitCipher( sal_uInt32 nCounter );
-
-    /** Creates an MD5 digest of salt digest. */
-    void               CreateSaltDigest(
-                            const sal_uInt8 nSaltData[16], sal_uInt8 nSaltDigest[16] );
+    virtual bool                InitCipher(sal_uInt32 nCounter) = 0;
 
     /** Encodes a block of memory.
 
@@ -277,9 +236,8 @@ public:
         @return
             true = Encoding was successful (no error occurred).
     */
-    bool                Encode(
-                            const void* pData, std::size_t nDatLen,
-                            sal_uInt8* pBuffer, std::size_t nBufLen );
+    bool                Encode(const void* pData, std::size_t nDatLen,
+                               sal_uInt8* pBuffer, std::size_t nBufLen);
 
     /** Decodes a block of memory.
 
@@ -303,9 +261,8 @@ public:
         @return
             true = Decoding was successful (no error occurred).
     */
-    bool                Decode(
-                            const void* pData, std::size_t nDatLen,
-                            sal_uInt8* pBuffer, std::size_t nBufLen );
+    bool                Decode(const void* pData, std::size_t nDatLen,
+                               sal_uInt8* pBuffer, std::size_t nBufLen);
 
     /** Lets the cipher skip a specific amount of bytes.
 
@@ -319,7 +276,95 @@ public:
         @param nDatLen
             Number of bytes to be skipped (cipher "seeks" forward).
      */
-    bool                Skip( std::size_t nDatLen );
+    bool                Skip(std::size_t nDatLen);
+
+private:
+                        MSCodec97(const MSCodec97&) = delete;
+    MSCodec97&          operator=(const MSCodec97&) = delete;
+
+protected:
+    rtlCipher           m_hCipher;
+};
+
+/** Encodes and decodes data from protected MSO 97+ documents.
+
+    This is a wrapper class around low level cryptographic functions from RTL.
+    Implementation is based on the wvDecrypt package by Caolan McNamara:
+    http://www.csn.ul.ie/~caolan/docs/wvDecrypt.html
+ */
+class MSFILTER_DLLPUBLIC MSCodec_Std97 :  public MSCodec97
+{
+public:
+    explicit            MSCodec_Std97();
+                        ~MSCodec_Std97();
+
+    /** Initializes the algorithm with the encryption data.
+
+        @param aData
+            The sequence contains the necessary data to initialize
+            the codec.
+     */
+    virtual bool InitCodec(const css::uno::Sequence< css::beans::NamedValue >& aData) override;
+
+    /** Retrieves the encryption data
+
+        @return
+            The sequence contains the necessary data to initialize
+            the codec.
+     */
+    virtual css::uno::Sequence<css::beans::NamedValue> GetEncryptionData() override;
+
+
+    /** Initializes the algorithm with the specified password and document ID.
+
+        @param pPassData
+            Wide character array containing the password. Must be zero
+            terminated, which results in a maximum length of 15 characters.
+        @param pDocId
+            Unique document identifier read from or written to the file.
+     */
+    void                InitKey(
+                            const sal_uInt16 pPassData[ 16 ],
+                            const sal_uInt8 pDocId[ 16 ] );
+
+    /** Verifies the validity of the password using the passed salt data.
+
+        @precond
+            The codec must be initialized with InitKey() before this function
+            can be used.
+
+        @param pSaltData
+            Salt data block read from the file.
+        @param pSaltDigest
+            Salt digest read from the file.
+
+        @return
+            true = Test was successful.
+     */
+    bool                VerifyKey(
+                            const sal_uInt8 pSaltData[ 16 ],
+                            const sal_uInt8 pSaltDigest[ 16 ] );
+
+    /** Rekeys the codec using the specified counter.
+
+        After reading a specific amount of data the cipher algorithm needs to
+        be rekeyed using a counter that counts the data blocks.
+
+        The block size is for example 512 Bytes for Word files and 1024 Bytes
+        for Excel files.
+
+        @precond
+            The codec must be initialized with InitKey() before this function
+            can be used.
+
+        @param nCounter
+            Block counter used to rekey the cipher.
+     */
+    virtual bool InitCipher(sal_uInt32 nCounter) override;
+
+    /** Creates an MD5 digest of salt digest. */
+    void               CreateSaltDigest(
+                            const sal_uInt8 nSaltData[16], sal_uInt8 nSaltDigest[16] );
 
     /** Gets salt data and salt digest.
 
@@ -349,7 +394,6 @@ private:
                         MSCodec_Std97( const MSCodec_Std97& ) = delete;
     MSCodec_Std97&      operator=( const MSCodec_Std97& ) = delete;
 
-    rtlCipher           m_hCipher;
     rtlDigest           m_hDigest;
     sal_uInt8           m_pDigestValue[ RTL_DIGEST_LENGTH_MD5 ];
     sal_uInt8           m_pDocId[16];