class KMD5

An adapted C++ implementation of RSA Data Securities MD5 algorithm. More...

Definition#include <kmdcodec.h>
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Detailed Description

This class provides an easy to use C++ implementation of the MD5 algorithm. It provides an easy way to use the class much like you would the plain C-implementations along with single shot constructors that automatically perform the update and call finalize.

The default constructor is intended to provide much the same functionality as the C-implementation while the other three constructors are used to perform quick digest calculations whenever the message to be does not require subsequent updating. Additionally, you can obtain either the result in a 16-byte binary format or 33-byte hexidecimal by invoking rawDigest and @ hexDigest respectivelly. NOTE the extra byte in the latter format is is a NULL character to terminate the string.

Example:

The simplest way of using this class through one of the accessor methods:


  KMD5 context( QCString("ONE") );
  printf ( "Raw Digest output: %s", static_cast<char*>(context.rawDigest() );
  printf ( "Hex Digest output: %s", context.hexDigest() );

You can then invoke reset() to re-use the same class to perform another digest.

context.reset(); context.update( QCString("TWO") ); context.update( QCString("THREE") ); printf ( "Raw Digest output: %s", static_cast<char*>(context.rawDigest() ); printf ( "Hex Digest output: %s", context.hexDigest() );

Note that once you invoke reset(), the previouly calculated digest value will be lost. Thus, be sure you copy the result if you need to use it again. Also you cannot invoke update() if you use one of the convienence constructors unless you first invoke reset(). Hence, if you need to update the message to be digested, it is better to use the default constructor to avoid this subtle error.

The conventional (C-implemetation like) method of using this class:


  KMD5 context;
  context.update(QCString("ONE"));
  context.update(QCString("TWO"));
  context.update(QCString("THREE")); 
  context.finalize();
  printf ( "Raw Digest output: %s", static_cast<char*>(context.rawDigest() );
  printf ( "Hex Digest output: %s", context.hexDigest() );

enum DigestType { BIN, HEX }

DigestType

HEX hexidecimal representation of the message digest BIN binary representation of the message digest

enum ErrorType { ERR_NONE, ERR_ALREADY_FINALIZED, ERR_NOT_YET_FINALIZED, ERR_CANNOT_READ_FILE, ERR_CANNOT_CLOSE_FILE }

ErrorType

ERR_NONE no error occured. [default] ERR_ALREADY_FINALIZED finalize() has already been invoked. ERR_NOT_YET_FINALIZED digest() or rawDigest() invoked before finalize(). ERR_CANNOT_READ_FILE indicates a problem while trying to read the given file. ERR_CANNOT_CLOSE_FILE indicates a problem while trying to close the given file.

 KMD5 ()

KMD5

Default constructor that only performs initialization. Unlike the other constructors

 KMD5 (FILE *file)

KMD5

Constructor that initializes, computes, and finalizes the message digest for the given file.

NOTE: This is a convience constructor. As such it does not allow the update of the message after it has been invoked. If you need to update the message after creating the constructor,

 KMD5 (Q_UINT8 * input)

KMD5

Constructor that initializes, computes, and finalizes the message digest for the given string.

 KMD5 (const QCString& input)

KMD5

Same as above except it takes a QCString as input.

 KMD5 (const QString& input)

KMD5

Same as above except it takes a QString as input.

void  update (Q_UINT8 * input, int len = -1 )

update

Updates the message to be digested.

Parameters:
inputmessage to be added to digest (unsigned char*)
lenthe length of the given message.

void  update ( const QCString& input )

update

Same as above except except it takes a QCString as the argument.

void  update ( const QString& input )

update

Same as above except it takes a QString as the argument.

void  update (FILE *file, bool closeFile = false )

update

Same as above except it accepts a pointer to FILE.

NOTE that the file must have been already opened. If you want the file to be automatically closed, set closeFile to TRUE.

Parameters:
filea pointer to FILE as returned by calls like f{d,re}open
closeFileif true closes the file using fclose.

void  finalize ()

finalize

Finalizes the message digest calculation.

If you used the default constructor, you must invoke this function before you can obtain the calculated digest value.

bool  verify ( const QCString& input, const char * msg_digest, DigestType type = HEX )

verify

Compares the message digest supplied messaged digest msg_digest with the one calculated for the input QCString input.

NOTE: Calling this function will reset any previously calcualted digests. If you want to verify your token with the current digest value, use verify( const char*, DigestType ) instead.

Parameters:
inputthe message to be added to the digest value
msg_digestthe digest to compare the result against
typethe format of the result for comparison (binary or hexidecimal).

Returns: true if the digests match, otherwise false.

bool  verify ( const QString& input, const char * msg_digest, DigestType type = HEX )

verify

Same as above except the input is a QString instead.

NOTE: Calling this function will reset any previously calcualted digests. If you want to verify your token with the current digest value, use verify( const char*, DigestType ) instead.

bool  verify ( FILE* f, const char * msg_digest, DigestType type = HEX )

verify

Same as above except the input is a pointer for a FILE instead.

NOTE: Calling this function will reset any previously calcualted digests. If you want to verify your token with the current digest value, use verify( const char*, DigestType ) instead.

bool  verify ( const char* msg_digest, DigestType type = HEX )

verify

Compares the given string with with the current message digest.

NOTE: Unlike the other verify functions this one does not reset the current message digest if one is already present. It is meant to allow you to compare against the existing message digest. Also note that this function will return false if a digest has yet to be calculated.

Parameters:
msg_digestthe digest to compare the result against
typethe format of the result for comparison (binary or hexidecimal).

Returns: true if the digests match, otherwise false.

void  reset ()

reset

Re-initializes internal paramters.

Note that calling this function will reset all internal variables and hence any calculated digest. Invoke this function only when you have to re-use the same object to perform another message digest calculation.

Q_UINT8*  rawDigest ()

rawDigest

Returns the raw 16-byte binary value of the message digest.

NOTE: you are responsible for making a copy of this string.

void  rawDigest ( HASH bin )

rawDigest

Fills the given array with the binary representation of the message digest.

Use this method if you do not want to worry about making copy of the digest once you obtain it.

Parameters:
binan array of 16 characters ( char[16] )

Returns: true if the raw digest is ready, otherwise false.

char *  hexDigest ()

hexDigest

Returns a the value of the calculated message digest. This is a 32 byte hexidecimal value terminated by a NULL character.

NOTE: you are responsible for making a copy of this string.

void  hexDigest ( HASHHEX hex )

hexDigest

Fills the given array with the hexcidecimal representation of the message digest.

Use this method if you do not want to worry about making copy of the digest once you obtain it. Also note that this method will append a terminating NULL charater.

Parameters:
binan array of 33 characters ( char[33] )

Returns: true if the digest is ready, otherwise false.

bool  hasErrored ()

hasErrored

[const]

Indicates whether the message digest calculation failed or succeeded. Use error to determine the error type.

Returns: true if

int  error ()

error

[const]

Returns the type error that occurred. See ErrorType for descriptions.

void  init ()

init

[protected]

Initializer called by all constructors

void  transform ( Q_UINT8 * buffer )

transform

[protected]

Performs the real update work. Note that length is implied to be 64.

bool  isDigestMatch ( const char * msg_digest, DigestType type )

isDigestMatch

[protected]

Returns true if the current message digest matches msg_digest.