Elgamal Class

Properties   Methods   Events   Config Settings   Errors  

Encrypt and decrypt data with the Elgamal asymmetric key encryption algorithm for public-key cryptography.

Syntax

Elgamal

Remarks

The ElGamal class is used to encrypt/decrypt data with the Elgamal asymmetric key encryption algorithm for public-key cryptography.

To begin you must either specify an existing key or create a new key. Existing public or private keys may be specified by setting the Key* properties. To create a new key pair call CreateKey.

After specifying a key, specify the data you wish to encrypt or decrypt. Call the Encrypt or Decrypt method to perform the operation.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

• SetInputStream
• InputFile
• InputMessage

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

An Elgamal key is made up of a number of individual parameters.

The public key consists of the following parameters:

• KeyP
• KeyG
• KeyY

The class also includes the KeyPublicKey property which holds the PEM formatted public key for ease of use. This is helpful if you are in control of both signature creation and verification process. When sending the public key to a recipient note that not all implementations will support using the PEM formatted value in KeyPublicKey in which case the individual parameters must be sent.

The private key consists of the following parameters:

• KeyP
• KeyG
• KeyY
• KeyX

Property List

The following is the full list of the properties of the class with short descriptions. Click on the links for further details.

Method List

The following is the full list of the methods of the class with short descriptions. Click on the links for further details.

Event List

The following is the full list of the events fired by the class with short descriptions. Click on the links for further details.

Config Settings

The following is a list of config settings for the class with short descriptions. Click on the links for further details.

InputFile Property (Elgamal Class)

The file to process.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
char* GetInputFile();
int SetInputFile(const char* lpszInputFile);

Unicode (Windows)
LPWSTR GetInputFile();
INT SetInputFile(LPCWSTR lpszInputFile);

char* ipworksencrypt_elgamal_getinputfile(void* lpObj);
int ipworksencrypt_elgamal_setinputfile(void* lpObj, const char* lpszInputFile);

QString GetInputFile();
int SetInputFile(QString qsInputFile);

Default Value

""

Remarks

This property specifies the file to be processed. Set this property to the full or relative path to the file which will be processed.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

• SetInputStream
• InputFile
• InputMessage

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

Data Type

String

InputMessage Property (Elgamal Class)

The message to process.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetInputMessage(char* &lpInputMessage, int &lenInputMessage);
int SetInputMessage(const char* lpInputMessage, int lenInputMessage);

Unicode (Windows)
INT GetInputMessage(LPSTR &lpInputMessage, INT &lenInputMessage);
INT SetInputMessage(LPCSTR lpInputMessage, INT lenInputMessage);

int ipworksencrypt_elgamal_getinputmessage(void* lpObj, char** lpInputMessage, int* lenInputMessage);
int ipworksencrypt_elgamal_setinputmessage(void* lpObj, const char* lpInputMessage, int lenInputMessage);

QByteArray GetInputMessage();
int SetInputMessage(QByteArray qbaInputMessage);

Default Value

""

Remarks

This property specifies the message to be processed.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

• SetInputStream
• InputFile
• InputMessage

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

Data Type

Binary String

KeyG Property (Elgamal Class)

Represents the G parameter for the Elgamal algorithm.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetKeyG(char* &lpKeyG, int &lenKeyG);
int SetKeyG(const char* lpKeyG, int lenKeyG);

Unicode (Windows)
INT GetKeyG(LPSTR &lpKeyG, INT &lenKeyG);
INT SetKeyG(LPCSTR lpKeyG, INT lenKeyG);

int ipworksencrypt_elgamal_getkeyg(void* lpObj, char** lpKeyG, int* lenKeyG);
int ipworksencrypt_elgamal_setkeyg(void* lpObj, const char* lpKeyG, int lenKeyG);

QByteArray GetKeyG();
int SetKeyG(QByteArray qbaKeyG);

Default Value

""

Remarks

Represents the G parameter for the Elgamal algorithm.

Data Type

Binary String

KeyP Property (Elgamal Class)

Represents the P parameter for the Elgamal algorithm.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetKeyP(char* &lpKeyP, int &lenKeyP);
int SetKeyP(const char* lpKeyP, int lenKeyP);

Unicode (Windows)
INT GetKeyP(LPSTR &lpKeyP, INT &lenKeyP);
INT SetKeyP(LPCSTR lpKeyP, INT lenKeyP);

int ipworksencrypt_elgamal_getkeyp(void* lpObj, char** lpKeyP, int* lenKeyP);
int ipworksencrypt_elgamal_setkeyp(void* lpObj, const char* lpKeyP, int lenKeyP);

QByteArray GetKeyP();
int SetKeyP(QByteArray qbaKeyP);

Default Value

""

Remarks

Represents the P parameter for the Elgamal algorithm.

Data Type

Binary String

KeyPrivateKey Property (Elgamal Class)

This property is a PEM formatted private key.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
char* GetKeyPrivateKey();
int SetKeyPrivateKey(const char* lpszKeyPrivateKey);

Unicode (Windows)
LPWSTR GetKeyPrivateKey();
INT SetKeyPrivateKey(LPCWSTR lpszKeyPrivateKey);

char* ipworksencrypt_elgamal_getkeyprivatekey(void* lpObj);
int ipworksencrypt_elgamal_setkeyprivatekey(void* lpObj, const char* lpszKeyPrivateKey);

QString GetKeyPrivateKey();
int SetKeyPrivateKey(QString qsKeyPrivateKey);

Default Value

""

Remarks

This property is a PEM formatted private key. The purpose of this property is to allow easier management of the private key parameters by using only a single value.

Data Type

String

KeyPublicKey Property (Elgamal Class)

This property is a PEM formatted public key.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
char* GetKeyPublicKey();
int SetKeyPublicKey(const char* lpszKeyPublicKey);

Unicode (Windows)
LPWSTR GetKeyPublicKey();
INT SetKeyPublicKey(LPCWSTR lpszKeyPublicKey);

char* ipworksencrypt_elgamal_getkeypublickey(void* lpObj);
int ipworksencrypt_elgamal_setkeypublickey(void* lpObj, const char* lpszKeyPublicKey);

QString GetKeyPublicKey();
int SetKeyPublicKey(QString qsKeyPublicKey);

Default Value

""

Remarks

This property is a PEM formatted public key. The purpose of this property is to allow easier management of the public key parameters by using only a single value.

Data Type

String

KeyX Property (Elgamal Class)

Represents the X parameter for the Elgamal algorithm.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetKeyX(char* &lpKeyX, int &lenKeyX);
int SetKeyX(const char* lpKeyX, int lenKeyX);

Unicode (Windows)
INT GetKeyX(LPSTR &lpKeyX, INT &lenKeyX);
INT SetKeyX(LPCSTR lpKeyX, INT lenKeyX);

int ipworksencrypt_elgamal_getkeyx(void* lpObj, char** lpKeyX, int* lenKeyX);
int ipworksencrypt_elgamal_setkeyx(void* lpObj, const char* lpKeyX, int lenKeyX);

QByteArray GetKeyX();
int SetKeyX(QByteArray qbaKeyX);

Default Value

""

Remarks

Represents the X parameter for the Elgamal algorithm.

Data Type

Binary String

KeyY Property (Elgamal Class)

Represents the Y parameter for the Elgamal algorithm.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetKeyY(char* &lpKeyY, int &lenKeyY);
int SetKeyY(const char* lpKeyY, int lenKeyY);

Unicode (Windows)
INT GetKeyY(LPSTR &lpKeyY, INT &lenKeyY);
INT SetKeyY(LPCSTR lpKeyY, INT lenKeyY);

int ipworksencrypt_elgamal_getkeyy(void* lpObj, char** lpKeyY, int* lenKeyY);
int ipworksencrypt_elgamal_setkeyy(void* lpObj, const char* lpKeyY, int lenKeyY);

QByteArray GetKeyY();
int SetKeyY(QByteArray qbaKeyY);

Default Value

""

Remarks

Represents the Y parameter for the Elgamal algorithm.

Data Type

Binary String

OutputFile Property (Elgamal Class)

The output file when encrypting or decrypting.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
char* GetOutputFile();
int SetOutputFile(const char* lpszOutputFile);

Unicode (Windows)
LPWSTR GetOutputFile();
INT SetOutputFile(LPCWSTR lpszOutputFile);

char* ipworksencrypt_elgamal_getoutputfile(void* lpObj);
int ipworksencrypt_elgamal_setoutputfile(void* lpObj, const char* lpszOutputFile);

QString GetOutputFile();
int SetOutputFile(QString qsOutputFile);

Default Value

""

Remarks

This property specifies the file to which the output will be written when Encrypt or Decrypt is called. This may be set to an absolute or relative path.

This property is only applicable to Encrypt and Decrypt.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

• SetInputStream
• InputFile
• InputMessage

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

Data Type

String

OutputMessage Property (Elgamal Class)

The output message after processing.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetOutputMessage(char* &lpOutputMessage, int &lenOutputMessage);

Unicode (Windows)
INT GetOutputMessage(LPSTR &lpOutputMessage, INT &lenOutputMessage);

int ipworksencrypt_elgamal_getoutputmessage(void* lpObj, char** lpOutputMessage, int* lenOutputMessage);

QByteArray GetOutputMessage();

Default Value

""

Remarks

This property will be populated with the output from the operation if OutputFile is not set.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

• SetInputStream
• InputFile
• InputMessage

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

This property is read-only and not available at design time.

Data Type

Binary String

Overwrite Property (Elgamal Class)

Indicates whether or not the class should overwrite files.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetOverwrite();
int SetOverwrite(int bOverwrite);

Unicode (Windows)
BOOL GetOverwrite();
INT SetOverwrite(BOOL bOverwrite);

int ipworksencrypt_elgamal_getoverwrite(void* lpObj);
int ipworksencrypt_elgamal_setoverwrite(void* lpObj, int bOverwrite);

bool GetOverwrite();
int SetOverwrite(bool bOverwrite);

Default Value

FALSE

Remarks

This property indicates whether or not the class will overwrite OutputFile. If Overwrite is False, an error will be thrown whenever OutputFile exists before an operation. The default value is False.

Data Type

Boolean

RecipientKeyG Property (Elgamal Class)

Represents the G parameter for the Elgamal algorithm.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetRecipientKeyG(char* &lpRecipientKeyG, int &lenRecipientKeyG);
int SetRecipientKeyG(const char* lpRecipientKeyG, int lenRecipientKeyG);

Unicode (Windows)
INT GetRecipientKeyG(LPSTR &lpRecipientKeyG, INT &lenRecipientKeyG);
INT SetRecipientKeyG(LPCSTR lpRecipientKeyG, INT lenRecipientKeyG);

int ipworksencrypt_elgamal_getrecipientkeyg(void* lpObj, char** lpRecipientKeyG, int* lenRecipientKeyG);
int ipworksencrypt_elgamal_setrecipientkeyg(void* lpObj, const char* lpRecipientKeyG, int lenRecipientKeyG);

QByteArray GetRecipientKeyG();
int SetRecipientKeyG(QByteArray qbaRecipientKeyG);

Default Value

""

Remarks

Represents the G parameter for the Elgamal algorithm.

Data Type

Binary String

RecipientKeyP Property (Elgamal Class)

Represents the P parameter for the Elgamal algorithm.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetRecipientKeyP(char* &lpRecipientKeyP, int &lenRecipientKeyP);
int SetRecipientKeyP(const char* lpRecipientKeyP, int lenRecipientKeyP);

Unicode (Windows)
INT GetRecipientKeyP(LPSTR &lpRecipientKeyP, INT &lenRecipientKeyP);
INT SetRecipientKeyP(LPCSTR lpRecipientKeyP, INT lenRecipientKeyP);

int ipworksencrypt_elgamal_getrecipientkeyp(void* lpObj, char** lpRecipientKeyP, int* lenRecipientKeyP);
int ipworksencrypt_elgamal_setrecipientkeyp(void* lpObj, const char* lpRecipientKeyP, int lenRecipientKeyP);

QByteArray GetRecipientKeyP();
int SetRecipientKeyP(QByteArray qbaRecipientKeyP);

Default Value

""

Remarks

Represents the P parameter for the Elgamal algorithm.

Data Type

Binary String

RecipientKeyPublicKey Property (Elgamal Class)

This property is a PEM formatted public key.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
char* GetRecipientKeyPublicKey();
int SetRecipientKeyPublicKey(const char* lpszRecipientKeyPublicKey);

Unicode (Windows)
LPWSTR GetRecipientKeyPublicKey();
INT SetRecipientKeyPublicKey(LPCWSTR lpszRecipientKeyPublicKey);

char* ipworksencrypt_elgamal_getrecipientkeypublickey(void* lpObj);
int ipworksencrypt_elgamal_setrecipientkeypublickey(void* lpObj, const char* lpszRecipientKeyPublicKey);

QString GetRecipientKeyPublicKey();
int SetRecipientKeyPublicKey(QString qsRecipientKeyPublicKey);

Default Value

""

Remarks

This property is a PEM formatted public key. The purpose of this property is to allow easier management of the public key parameters by using only a single value.

Data Type

String

RecipientKeyY Property (Elgamal Class)

Represents the Y parameter for the Elgamal algorithm.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetRecipientKeyY(char* &lpRecipientKeyY, int &lenRecipientKeyY);
int SetRecipientKeyY(const char* lpRecipientKeyY, int lenRecipientKeyY);

Unicode (Windows)
INT GetRecipientKeyY(LPSTR &lpRecipientKeyY, INT &lenRecipientKeyY);
INT SetRecipientKeyY(LPCSTR lpRecipientKeyY, INT lenRecipientKeyY);

int ipworksencrypt_elgamal_getrecipientkeyy(void* lpObj, char** lpRecipientKeyY, int* lenRecipientKeyY);
int ipworksencrypt_elgamal_setrecipientkeyy(void* lpObj, const char* lpRecipientKeyY, int lenRecipientKeyY);

QByteArray GetRecipientKeyY();
int SetRecipientKeyY(QByteArray qbaRecipientKeyY);

Default Value

""

Remarks

Represents the Y parameter for the Elgamal algorithm.

Data Type

Binary String

UseHex Property (Elgamal Class)

Whether input or output is hex encoded.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetUseHex();
int SetUseHex(int bUseHex);

Unicode (Windows)
BOOL GetUseHex();
INT SetUseHex(BOOL bUseHex);

int ipworksencrypt_elgamal_getusehex(void* lpObj);
int ipworksencrypt_elgamal_setusehex(void* lpObj, int bUseHex);

bool GetUseHex();
int SetUseHex(bool bUseHex);

Default Value

FALSE

Remarks

This property specifies whether the encrypted data is hex encoded.

If set to True, when Encrypt is called the class will perform the encryption as normal and then hex encode the output. OutputMessage or OutputFile will hold hex encoded data.

If set to True, when Decrypt is called the class will expect InputMessage or InputFile to hold hex encoded data. The class will then hex decode the data and perform decryption as normal.

Data Type

Boolean

Config Method (Elgamal Class)

Sets or retrieves a configuration setting.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
char* Config(const char* lpszConfigurationString);

Unicode (Windows)
LPWSTR Config(LPCWSTR lpszConfigurationString);

char* ipworksencrypt_elgamal_config(void* lpObj, const char* lpszConfigurationString);

QString Config(const QString& qsConfigurationString);

Remarks

Config is a generic method available in every class. It is used to set and retrieve configuration settings for the class.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the class, access to these internal properties is provided through the Config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

Error Handling (C++)

This method returns a String value; after it returns, call the GetLastErrorCode() method to obtain its result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message.

CreateKey Method (Elgamal Class)

Creates a new key.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int CreateKey();

Unicode (Windows)
INT CreateKey();

int ipworksencrypt_elgamal_createkey(void* lpObj);

int CreateKey();

Remarks

This method creates a new public and private key.

When calling CreateKey the Key* properties are populated with a new private and public key.

An Elgamal key is made up of a number of individual parameters.

The public key consists of the following parameters:

• KeyP
• KeyG
• KeyY

The class also includes the KeyPublicKey property which holds the PEM formatted public key for ease of use. This is helpful if you are in control of both signature creation and verification process. When sending the public key to a recipient note that not all implementations will support using the PEM formatted value in KeyPublicKey in which case the individual parameters must be sent.

The private key consists of the following parameters:

• KeyP
• KeyG
• KeyY
• KeyX

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

Decrypt Method (Elgamal Class)

Decrypts the input data using the specified private key.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int Decrypt();

Unicode (Windows)
INT Decrypt();

int ipworksencrypt_elgamal_decrypt(void* lpObj);

int Decrypt();

Remarks

This method decrypts the input data using the private key specified in the Key* properties. Alternatively, a certificate may be specified by setting Certificate

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

• SetInputStream
• InputFile
• InputMessage

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

Key Size and the Maximum Length of Data

RSA has an upper limit to the amount of data that can be encrypted or decrypted, also known as message length. This can typically be calculated as the size of the key minus the size of the RSA header and padding.

When not using OAEP, the following formula and table can be referenced. (RSA Key Bytes) - (Header Bytes) = Length of data, where Header Bytes is always 11.

When using OAEP, the following formula and table can be referenced. (RSA Key Bytes) - (2 * Hash Length Bytes) - 2 = Length of data. The table below assumes SHA-256 for the hash, so Hash Length Bytes is 32.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

Encrypt Method (Elgamal Class)

Encrypts the input data using the recipient's public key.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int Encrypt();

Unicode (Windows)
INT Encrypt();

int ipworksencrypt_elgamal_encrypt(void* lpObj);

int Encrypt();

Remarks

This method encrypts the input data using the public key specified in the RecipientKey* properties. Alternatively, a certificate may be specified by setting RecipientCert

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

• SetInputStream
• InputFile
• InputMessage

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

Key Size and the Maximum Length of Data

RSA has an upper limit to the amount of data that can be encrypted or decrypted, also known as message length. This can typically be calculated as the size of the key minus the size of the RSA header and padding.

When not using OAEP, the following formula and table can be referenced. (RSA Key Bytes) - (Header Bytes) = Length of data, where Header Bytes is always 11.

When using OAEP, the following formula and table can be referenced. (RSA Key Bytes) - (2 * Hash Length Bytes) - 2 = Length of data. The table below assumes SHA-256 for the hash, so Hash Length Bytes is 32.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

Reset Method (Elgamal Class)

Resets the class.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int Reset();

Unicode (Windows)
INT Reset();

int ipworksencrypt_elgamal_reset(void* lpObj);

int Reset();

Remarks

When called, the class will reset all of its properties to their default values.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

SetInputStream Method (Elgamal Class)

Sets the stream from which the class will read data to encrypt or decrypt.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int SetInputStream(IPWorksEncryptStream* sInputStream);

Unicode (Windows)
INT SetInputStream(IPWorksEncryptStream* sInputStream);

int ipworksencrypt_elgamal_setinputstream(void* lpObj, IPWorksEncryptStream* sInputStream);

int SetInputStream(IPWorksEncryptStream* sInputStream);

Remarks

This method sets the stream from which the class will read data to encrypt or decrypt.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

• SetInputStream
• InputFile
• InputMessage

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

Error Event (Elgamal Class)

Information about errors during data delivery.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
virtual int FireError(ElgamalErrorEventParams *e);

typedef struct {
  int ErrorCode;
  const char *Description;
  int reserved;
} ElgamalErrorEventParams;


Unicode (Windows)
virtual INT FireError(ElgamalErrorEventParams *e);

typedef struct {
  INT ErrorCode;
  LPCWSTR Description;
  INT reserved;
} ElgamalErrorEventParams;

#define EID_ELGAMAL_ERROR 1

virtual INT IPWORKSENCRYPT_CALL FireError(INT &iErrorCode, LPSTR &lpszDescription);

class ElgamalErrorEventParams {
public:
  int ErrorCode();

  const QString &Description();

  int EventRetVal();
  void SetEventRetVal(int iRetVal);
};

// To handle, connect one or more slots to this signal.
void Error(ElgamalErrorEventParams *e);

// Or, subclass Elgamal and override this emitter function.
virtual int FireError(ElgamalErrorEventParams *e) {...}

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the class fails with an error.

ErrorCode contains an error code and Description contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Error Codes section.

IPWorksEncryptStream Type

Syntax

IPWorksEncryptStream (declared in ipworksencrypt.h)

Remarks

The Elgamal class includes one or more API members that take a stream object as a parameter. To use such API members, create a concrete class that implements the IPWorksEncryptStream interface and pass the Elgamal class an instance of that concrete class.

When implementing the IPWorksEncryptStream interface's properties and methods, they must behave as described below. If the concrete class's implementation does not behave as expected, undefined behavior may occur.

bool CanRead() { return true; }

bool CanSeek() { return true; }

bool CanWrite() { return true; }

int64 GetLength() = 0;

void Close() {}

int Flush() { return 0; }

int Read(void* buffer, int count) = 0;

int64 Seek(int64 offset, int seekOrigin) = 0;

int Write(const void* buffer, int count) = 0;

Config Settings (Elgamal Class)

Elgamal Config Settings

Base Config Settings

Trappable Errors (Elgamal Class)

Error Handling (C++)

Call the GetLastErrorCode() method to obtain the last called method's result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. Known error codes are listed below. If an error occurs, the GetLastError() method can be called to retrieve the associated error message.

Elgamal Errors