CMessageDigest Class Reference

#include <hash.h>

Link against: hash.lib

class CMessageDigest : public CBase

Inherits from

CMessageDigest
- CBase

Public Member Enumerations
enum	THashId { EMD2, EMD5, ESHA1, HMAC, ..., ESHA512 }

Public Member Functions
	~CMessageDigest(void)
pure virtual IMPORT_C TInt	BlockSize(void)
pure virtual IMPORT_C CMessageDigest *	CopyL(void)
pure virtual IMPORT_C TPtrC8	Final(const TDesC8 &)
pure virtual IMPORT_C TPtrC8	Final(void)
TInt	GetExtension(TUint, TAny &, TAny )
pure virtual IMPORT_C TPtrC8	Hash(const TDesC8 &)
pure virtual IMPORT_C TInt	HashSize(void)
pure virtual IMPORT_C CMessageDigest *	ReplicateL(void)
pure virtual IMPORT_C void	Reset(void)
pure virtual void	RestoreState()
pure virtual void	StoreState()
pure virtual IMPORT_C void	Update(const TDesC8 &)

Protected Member Functions
	CMessageDigest(void)
	CMessageDigest(const CMessageDigest &)

Inherited Functions
	CBase::CBase()
	CBase::Delete(CBase *)
	CBase::Extension_(TUint,TAny &,TAny )
	CBase::operator new(TUint)
	CBase::operator new(TUint,TAny *)
	CBase::operator new(TUint,TLeave)
	CBase::operator new(TUint,TLeave,TUint)
	CBase::operator new(TUint,TUint)
	CBase::~CBase()

Detailed Description

Base class for message digests.

Member Enumeration Documentation

Enum THashId

Enumeration to identify hash functions (aka message-digest algorithms).

Enumerator	Value	Description
EMD2		Message Digest algorithm developed by Rivest for digital signature applications (and optimized for 8-bit machines). Takes a message of arbitrary length and produces a 128-bit message digest. See RFC 1319
EMD5		Message Digest algorithm developed by Rivest for digital signature applications (and optimized for 32-bit machines). Takes a message of arbitrary length and produces a 128-bit message digest. See RFC 1321
ESHA1		Secure Hash Algorithm (version 1) is a message digest algorithm developed by NIST, along with the NSA, for use with the Digital Signature Standard (DSS). It takes a message of less than 2^64 bits in length and produces a 160-bit message digest. See FIPS 180-1 and RFC 3174
HMAC		HMAC - Hash function based Message Authentication Code is a mechanism for message authentication using cryptographic hash functions. (A checksum.) It can be used with any iterative cryptographic hash function, e.g., MD5, SHA-1, in combination with a secret shared key to produce a checksum that is appended to the message. The cryptographic strength of HMAC depends on the properties of the underlying hash function. See RFC 2104
EMD4		Message Digest algorithm developed by Rivest for digital signature applications (and optimized for 32-bit machines). Takes a message of arbitrary length and produces a 128-bit message digest. See RFC 1320
ESHA224		Secure Hash Algorithm - 224 (version 2) is a message digest algorithm developed by NIST, along with the NSA, for use with the Digital Signature Standard (DSS). It takes a message of less than 2^64 bits in length and produces a 224-bit message digest. See FIPS 180-2 (with change notice), RFC3874 and FIPS 180-3
ESHA256		Secure Hash Algorithm - 256 (version 2) is a message digest algorithm developed by NIST, along with the NSA, for use with the Digital Signature Standard (DSS). It takes a message of less than 2^64 bits in length and produces a 256-bit message digest. See FIPS 180-2 and RFC 4634
ESHA384		Secure Hash Algorithm - 384 (version 2) is a message digest algorithm developed by NIST, along with the NSA, for use with the Digital Signature Standard (DSS). It takes a message of less than 2^128 bits in length and produces a 384-bit message digest. See FIPS 180-2 and RFC 4634
ESHA512		Secure Hash Algorithm - 512 (version 2) is a message digest algorithm developed by NIST, along with the NSA, for use with the Digital Signature Standard (DSS). It takes a message of less than 2^128 bits in length and produces a 512-bit message digest. See FIPS 180-2 and RFC 4634

Constructor & Destructor Documentation

CMessageDigest ( void )

IMPORT_C

CMessageDigest

(

void

)

[protected]

Constructor

CMessageDigest ( const CMessageDigest & )

IMPORT_C

CMessageDigest

(

const CMessageDigest &

aMD

)

[protected]

Copy constructor

Parameters
aMD	A CMessageDigest object

~CMessageDigest ( void )

IMPORT_C

~CMessageDigest

(

void

)

Destructor.

Member Function Documentation

BlockSize ( void )

IMPORT_C TInt

BlockSize

(

void

)

[pure virtual]

Gets the internal block size of the message digest.

Return Value: Internal block size of message digest in bytes.

CopyL ( void )

IMPORT_C CMessageDigest *

CopyL

(

void

)

[pure virtual]

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: A pointer to the new CMessageDigest object

Final ( const TDesC8 & )

IMPORT_C TPtrC8

Final

(

const TDesC8 &

aMessage

)

[pure virtual]

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().

Since: v8.0

Parameters
aMessage	Data to be included in the hash

Return Value: A descriptor pointer to the buffer containing the resulting hash.

Final ( void )

IMPORT_C TPtrC8

Final

(

void

)

[pure virtual]

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

Since: v8.0

Return Value: A descriptor pointer to the buffer containing the resulting hash.

GetExtension ( TUint, TAny &, TAny )

TInt	GetExtension	(	TUint	aExtensionId,
			TAny *&	a0,
			TAny *	a1
		)

Used to retrieve the extended interfaces extension

Hash ( const TDesC8 & )

IMPORT_C TPtrC8

Hash

(

const TDesC8 &

aMessage

)

[pure virtual]

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
aMessage	Data to be included in the hash.

Return Value: A descriptor pointer to the buffer containing the resulting hash.

HashSize ( void )

IMPORT_C TInt

HashSize

(

void

)

[pure virtual]

Gets the size of the message digest output.

Return Value: Output size of the message digest in bytes.

ReplicateL ( void )

IMPORT_C CMessageDigest *

ReplicateL

(

void

)

[pure virtual]

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: A pointer to the new reset CMessageDigest object

Reset ( void )

IMPORT_C void

Reset

(

void

)

[pure virtual]

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().

RestoreState ( )

void

RestoreState

(

)

[pure virtual]

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

StoreState ( )

void

StoreState

(

)

[pure virtual]

Stores the internal state of the message digest.

Update ( const TDesC8 & )

IMPORT_C void

Update

(

const TDesC8 &

aMessage

)

[pure virtual]

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

Since: v8.0

Parameters
aMessage	Data to be included in the hash.

CMessageDigest Class Reference

Inherits from

Detailed Description

Member Enumeration Documentation

Enum THashId

Constructor & Destructor Documentation

CMessageDigest ( void )

CMessageDigest ( const CMessageDigest & )

~CMessageDigest ( void )

Member Function Documentation

BlockSize ( void )

CopyL ( void )

Final ( const TDesC8 & )

Final ( void )

GetExtension ( TUint, TAny *&, TAny * )

Hash ( const TDesC8 & )

HashSize ( void )

ReplicateL ( void )

Reset ( void )

RestoreState ( )

StoreState ( )

Update ( const TDesC8 & )

GetExtension ( TUint, TAny &, TAny )