Class CHMAC

class CHMAC : public CMessageDigest;

Description

An HMAC (Hashed Message Authentication Code)

Derivation

• CBase - Base class for all classes to be instantiated on the heap

• CMessageDigest - Base class for message digests

• CHMAC - An HMAC (Hashed Message Authentication Code)

Members

Defined in CHMAC:
BlockSize(), CopyL(), Final(), Final(), Hash(), HashSize(), NewL(), ReplicateL(), Reset(), RestoreState(), StoreState(), Update(), ~CHMAC()

Inherited from CBase:
Delete(), Extension_(), operator new()

Inherited from CMessageDigest:
EMD2, EMD5, ESHA1, HMAC, THashId

static IMPORT_C CHMAC *NewL(const TDesC8 &aKey, CMessageDigest *aDigest);

Description

Creates a new HMAC object from a specified type of message digest and authentication key.

Parameters

const TDesC8 &aKey Authentication key. CMessageDigest *aDigest A message digest to construct the HMAC from.

Return value

CHMAC * A pointer to the new CHMAC object. The resulting HMAC object takes ownership of aDigest and is responsible for its deletion.

IMPORT_C ~CHMAC(void);

Description

Destructor

virtual IMPORT_C CMessageDigest *ReplicateL(void);

Description

Creates a brand new reset CMessageDigest object containing no state information from the current object.

To make a copy of a message digest with its internal state intact, see CopyL().

Return value

CMessageDigest * A pointer to the new reset CMessageDigest object

virtual IMPORT_C TPtrC8 Hash(const TDesC8 &aMessage);

Description

Adds aMessage to the internal representation of data to be hashed, then returns a TPtrC8 of the finalised hash of all the previously appended messages.

Parameters

const TDesC8 &aMessage Data to be included in the hash.

Return value

TPtrC8 A descriptor pointer to the buffer containing the resulting hash.

virtual IMPORT_C CMessageDigest *CopyL(void);

Description

Creates a new CMessageDigest object with the exact same state as the current object.

This function copies all internal state of the message digest. To create a new CMessageDigest object without the state of the current object, see ReplicateL().

Return value

CMessageDigest * A pointer to the new CMessageDigest object

virtual IMPORT_C TInt BlockSize(void);

Description

Gets the internal block size of the message digest.

Return value

TInt Internal block size of message digest in bytes.

virtual IMPORT_C TInt HashSize(void);

Description

Gets the size of the message digest output.

Return value

TInt Output size of the message digest in bytes.

virtual IMPORT_C void Reset(void);

Description

Resets the internal state of the message digest.

A reset hash object loses all internal state representing the hashed data. A reset message digest is suitable to begin a new, distinct hash of different data. Any previously returned TPtrC8 from a call to Final() remains valid until any subsequent call to Update() or Final().

virtual IMPORT_C void Update(const TDesC8 &aMessage);

Description

Adds data to the internal representation of messages to be hashed.

Parameters

const TDesC8 &aMessage Data to be included in the hash.

virtual IMPORT_C TPtrC8 Final(const TDesC8 &aMessage);

Description

Adds aMessage to the internal representation of data to be hashed, returns a TPtrC8 of the finalised hash of all the previously appended messages, and calls Reset().

Parameters

const TDesC8 &aMessage Data to be included in the hash

Return value

TPtrC8 A descriptor pointer to the buffer containing the resulting hash.

virtual IMPORT_C TPtrC8 Final();

Description

Gets a TPtrC8 of the finalised hash of all the previously appended messages and then calls Reset().

Return value

TPtrC8 A descriptor pointer to the buffer containing the resulting hash.

virtual void RestoreState();

Description

Restores the internal state of the message digest to a previously stored state.

See also:

• StoreState()

virtual void StoreState();

Description

Stores the internal state of the message digest.