CASymCipherCTR Class Reference

This class could be used for encryption/decryption of data (streams) with AES using 128bit CTR mode. More...

Inheritance diagram for CASymCipherCTR:

Public Member Functions
	CASymCipherCTR ()
	~CASymCipherCTR ()
bool	isKeyValid ()
SINT32	setKey (const UINT8 *key)
	Sets the keys for crypt1() and crypt2() to the same key. More...
SINT32	setKeys (const UINT8 *key, UINT32 keysize)
	Sets the keys for crypt1() and crypt2() either to the same key (if keysize==KEY_SIZE) or to different values, if keysize==2* KEY_SIZE. More...
SINT32	setIVs (const UINT8 *p_iv)
	Sets iv1 and iv2 to p_iv. More...
SINT32	setIV2 (const UINT8 *p_iv)
	Sets iv2 to p_iv. More...
SINT32	crypt1 (const UINT8 *in, UINT8 *out, UINT32 len)
	Encryptes/Decrpytes in to out using iv1 and key1. More...
SINT32	crypt2 (const UINT8 *in, UINT8 *out, UINT32 len)
	Decryptes in to out using iv2 and key2. More...
Public Member Functions inherited from CALockAble
	CALockAble ()
virtual	~CALockAble ()
SINT32	lock ()
	Locks the lockable object by threadsafe incrementing a reference counter. More...
SINT32	unlock ()
	Unlocks the lockable object by threadsafe decrementing a reference counter. More...

Protected Attributes
EVP_CIPHER_CTX *	m_ctxAES1
EVP_CIPHER_CTX *	m_ctxAES2
UINT8	key1 [16]
UINT8	key2 [16]
UINT8 *	m_iv1
UINT8 *	m_iv2
bool	m_bKeySet

Private Attributes
CAMutex *	m_pcsEnc
CAMutex *	m_pcsDec

Additional Inherited Members
Static Public Member Functions inherited from CASymChannelCipher
static const UINT8 *const	getAlgorithmName (SYMCHANNELCIPHER_ALGORITHM alg)
Protected Member Functions inherited from CALockAble
SINT32	waitForDestroy ()
	If called checks if the reference counter equals zero. More...

Detailed Description

This class could be used for encryption/decryption of data (streams) with AES using 128bit CTR mode.

Because of the CTR mode technical encryption and decrpytion are the same (depending on the kind of input). Therefore there is only a general crypt() function. This class has a 2-in-1 feature: Two independent IVs are available. Therefore we have crypt1() and crypt2() depending on the used IV.

Constructor & Destructor Documentation

CASymCipherCTR()

CASymCipherCTR::CASymCipherCTR

(

)

References m_bKeySet, m_ctxAES1, m_ctxAES2, m_iv1, m_iv2, m_pcsDec, and m_pcsEnc.

~CASymCipherCTR()

CASymCipherCTR::~CASymCipherCTR

(

)

References m_iv1, m_iv2, m_pcsDec, m_pcsEnc, and CALockAble::waitForDestroy().

Member Function Documentation

crypt1()

SINT32 CASymCipherCTR::crypt1 ( const UINT8 *  in, UINT8 *  out, UINT32  len  )

virtual

Encryptes/Decrpytes in to out using iv1 and key1.

AES is used for encryption and the encryption is done with a special 128bit-OFB mode: In the case that (len mod 16 !=0) the unused cipher output bits are discarded and NOT used next time encryptAES() is called. That means that every time encrpytAES() is called at first new cipher output is created by calling AES-encrypt(iv).

Parameters

in	input (plain text) bytes
out	output (encrpyted) bytes
len	len of input. because the cipher preserves the size, len of output=len of input

Return values

E_SUCCESS

Implements CASymChannelCipher.

References E_SUCCESS, len, and m_ctxAES1.

crypt2()

SINT32 CASymCipherCTR::crypt2 ( const UINT8 *  in, UINT8 *  out, UINT32  len  )

virtual

Decryptes in to out using iv2 and key2.

Parameters

in	input (encrypted) bytes
out	output (decrpyted) bytes
len	len of input. because the cipher preserves the size, len of output=len of input

Return values

E_SUCCESS

Implements CASymChannelCipher.

References E_SUCCESS, len, and m_ctxAES2.

isKeyValid()

bool CASymCipherCTR::isKeyValid ( )

virtual

Implements CASymChannelCipher.

References m_bKeySet.

setIV2()

SINT32 CASymCipherCTR::setIV2 ( const UINT8 *  p_iv )

virtual

Sets iv2 to p_iv.

Parameters

p_iv	16 random bytes used for new iv2.

Return values

E_SUCCESS

Implements CASymChannelCipher.

References E_SUCCESS, key2, m_ctxAES2, and m_iv2.

setIVs()

SINT32 CASymCipherCTR::setIVs ( const UINT8 *  p_iv )

virtual

Sets iv1 and iv2 to p_iv.

Parameters

p_iv	16 random bytes used for new iv1 and iv2.

Return values

E_SUCCESS

Implements CASymChannelCipher.

References E_SUCCESS, key1, key2, m_ctxAES1, m_ctxAES2, m_iv1, and m_iv2.

setKey()

SINT32 CASymCipherCTR::setKey ( const UINT8 *  key )

virtual

Sets the keys for crypt1() and crypt2() to the same key.

Sets the key1 and key2 used for encryption/decryption to the same value of key.

Also resets the IVs to zero!

Parameters

key	16 random bytes used as key
bEncrypt	if true, the key should be used for encryption (otherwise it will be used for decryption)

Return values

E_SUCCESS

Implements CASymChannelCipher.

References E_SUCCESS, key1, key2, m_bKeySet, m_ctxAES1, m_ctxAES2, m_iv1, and m_iv2.

Referenced by setKeys().

setKeys()

SINT32 CASymCipherCTR::setKeys ( const UINT8 *  key, UINT32  keysize  )

virtual

Sets the keys for crypt1() and crypt2() either to the same key (if keysize==KEY_SIZE) or to different values, if keysize==2* KEY_SIZE.

Implements CASymChannelCipher.

References E_SUCCESS, E_UNKNOWN, key1, key2, KEY_SIZE, m_bKeySet, m_ctxAES1, m_ctxAES2, m_iv1, m_iv2, and setKey().

Member Data Documentation

key1

UINT8 CASymCipherCTR::key1[16]

protected

Referenced by setIVs(), setKey(), and setKeys().

key2

UINT8 CASymCipherCTR::key2[16]

protected

Referenced by setIV2(), setIVs(), setKey(), and setKeys().

m_bKeySet

bool CASymCipherCTR::m_bKeySet

protected

Referenced by CASymCipherCTR(), isKeyValid(), setKey(), and setKeys().

m_ctxAES1

EVP_CIPHER_CTX* CASymCipherCTR::m_ctxAES1

protected

Referenced by CASymCipherCTR(), crypt1(), setIVs(), setKey(), and setKeys().

m_ctxAES2

EVP_CIPHER_CTX* CASymCipherCTR::m_ctxAES2

protected

Referenced by CASymCipherCTR(), crypt2(), setIV2(), setIVs(), setKey(), and setKeys().

m_iv1

UINT8* CASymCipherCTR::m_iv1

protected

Referenced by CASymCipherCTR(), setIVs(), setKey(), setKeys(), and ~CASymCipherCTR().

m_iv2

UINT8* CASymCipherCTR::m_iv2

protected

Referenced by CASymCipherCTR(), setIV2(), setIVs(), setKey(), setKeys(), and ~CASymCipherCTR().

m_pcsDec

CAMutex* CASymCipherCTR::m_pcsDec

private

Referenced by CASymCipherCTR(), and ~CASymCipherCTR().

m_pcsEnc

CAMutex* CASymCipherCTR::m_pcsEnc

private

Referenced by CASymCipherCTR(), and ~CASymCipherCTR().