svx::MSCodec_Std97 Class Reference

Encodes and decodes data from protected MSO 97+ documents. More...

#include <mscodec.hxx>

List of all members.

Public Member Functions
	MSCodec_Std97 ()
	~MSCodec_Std97 ()
void	InitKey (const sal_uInt16 pPassData[16], const sal_uInt8 pUnique[16])
	Initializes the algorithm with the specified password and document ID.
bool	VerifyKey (const sal_uInt8 pSaltData[16], const sal_uInt8 pSaltDigest[16])
	Verifies the validity of the password using the passed salt data.
bool	InitCipher (sal_uInt32 nCounter)
	Rekeys the codec using the specified counter.
bool	Decode (const void *pData, sal_Size nDatLen, sal_uInt8 *pBuffer, sal_Size nBufLen)
	Decodes a block of memory.
bool	Skip (sal_Size nDatLen)
	Lets the cipher skip a specific amount of bytes.
Private Member Functions
SVX_DLLPRIVATE	MSCodec_Std97 (const MSCodec_Std97 &)
SVX_DLLPRIVATE MSCodec_Std97 &	operator= (const MSCodec_Std97 &)
Private Attributes
rtlCipher	m_hCipher
rtlDigest	m_hDigest
sal_uInt8	m_pDigestValue [RTL_DIGEST_LENGTH_MD5]

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Detailed Description

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

Definition at line 185 of file mscodec.hxx.

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Constructor & Destructor Documentation

svx::MSCodec_Std97::MSCodec_Std97

(

)

[explicit]

Definition at line 224 of file mscodec.cxx.

References m_hCipher, m_hDigest, and m_pDigestValue.

svx::MSCodec_Std97::~MSCodec_Std97

(

)

Definition at line 237 of file mscodec.cxx.

References m_hCipher, m_hDigest, and m_pDigestValue.

SVX_DLLPRIVATE svx::MSCodec_Std97::MSCodec_Std97

(

const MSCodec_Std97 &

)

[private]

---

Member Function Documentation

void svx::MSCodec_Std97::InitKey	(	const sal_uInt16	pPassData[16],
		const sal_uInt8	pUnique[16]
	)

Initializes the algorithm with the specified password and document ID.

Parameters:

	pPassData	Wide character array containing the password. Must be zero terminated, which results in a maximum length of 15 characters.
	pUnique	Unique document identifier read from or written to the file.

Definition at line 244 of file mscodec.cxx.

References m_hDigest, and m_pDigestValue.

bool svx::MSCodec_Std97::VerifyKey	(	const sal_uInt8	pSaltData[16],
		const sal_uInt8	pSaltDigest[16]
	)

Verifies the validity of the password using the passed salt data.

The codec must be initialized with InitKey() before this function can be used.

Parameters:

	pSaltData	Salt data block read from the file.
	pSaltDigest	Salt digest read from the file.

Returns:

true = Test was successful.

Definition at line 293 of file mscodec.cxx.

References InitCipher(), m_hCipher, and m_hDigest.

bool svx::MSCodec_Std97::InitCipher

(

sal_uInt32

nCounter

)

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.

The codec must be initialized with InitKey() before this function can be used.

Parameters:

nCounter

Block counter used to rekey the cipher.

Definition at line 333 of file mscodec.cxx.

References m_hCipher, m_hDigest, and m_pDigestValue.

Referenced by VerifyKey().

bool svx::MSCodec_Std97::Decode	(	const void *	pData,
		sal_Size	nDatLen,
		sal_uInt8 *	pBuffer,
		sal_Size	nBufLen
	)

Decodes a block of memory.

See also:

rtl_cipher_decode()

The codec must be initialized with InitKey() before this function can be used. The destination buffer must be able to take all encoded data from the source buffer (usually this means it must be as long as or longer than the source buffer).

Parameters:

	pData	Encrypted source data block.
	nDatLen	Size of the passed source data block.
	pBuffer	Destination buffer for the decrypted data.
	nBufLen	Size of the destination buffer.

Returns:

true = Decoding was successful (no error occured).

Definition at line 370 of file mscodec.cxx.

References m_hCipher.

Referenced by Skip().

bool svx::MSCodec_Std97::Skip

(

sal_Size

nDatLen

)

Lets the cipher skip a specific amount of bytes.

This function sets the cipher to the same state as if the specified amount of data has been decoded with one or more calls of Decode().

The codec must be initialized with InitKey() before this function can be used.

Parameters:

nDatLen

Number of bytes to be skipped (cipher "seeks" forward).

Definition at line 382 of file mscodec.cxx.

References Decode().

SVX_DLLPRIVATE MSCodec_Std97& svx::MSCodec_Std97::operator=

(

const MSCodec_Std97 &

)

[private]

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Member Data Documentation

rtlCipher svx::MSCodec_Std97::m_hCipher [private]

Definition at line 282 of file mscodec.hxx.

Referenced by Decode(), InitCipher(), MSCodec_Std97(), VerifyKey(), and ~MSCodec_Std97().

rtlDigest svx::MSCodec_Std97::m_hDigest [private]

Definition at line 283 of file mscodec.hxx.

Referenced by InitCipher(), InitKey(), MSCodec_Std97(), VerifyKey(), and ~MSCodec_Std97().

sal_uInt8 svx::MSCodec_Std97::m_pDigestValue[RTL_DIGEST_LENGTH_MD5] [private]

Definition at line 284 of file mscodec.hxx.

Referenced by InitCipher(), InitKey(), MSCodec_Std97(), and ~MSCodec_Std97().

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The documentation for this class was generated from the following files:

• mscodec.hxx
• mscodec.cxx