PBKDF Class

Properties   Methods   Events   Config Settings   Errors  

The PBKDF class supports using PBKDF1 and PBKDF2 to derive a key using a variety of algorithms.

Syntax

PBKDF

Remarks

The PBKDF component implements PBKDF2 and PBKDF1 (Password-Based Key Derivation Function 1 & 2) as described in RFC 2898.

The simplest way to use the component is to simply specify the Password and Salt and call CreateKey. Before calling CreateKey additional properties such as Algorithm, KeyLength, and Iterations may be set. The component supports a variety of algorithms including HMAC-SHA1, HMAC-SHA256, HMAC-MD5, and more.

The Version property controls whether PBKDF1 or PBKDF2 (default) is used, although it is recommended to use PBKDF2.

After calling CreateKey the derived key will be held in Key.

Code Example:

 
 Copy
Pbkdf pbkdf = new Pbkdf();
pbkdf.Password = "password";
pbkdf.Salt = "0123456789ABCDEF";
pbkdf.KeyLength = 4096;
pbkdf.CreateKey();
      
//Now do something with pbkdf.Key

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.

Algorithm Property (PBKDF Class)

The underlying pseudorandom function.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetAlgorithm();
int SetAlgorithm(int iAlgorithm);

Unicode (Windows)
INT GetAlgorithm();
INT SetAlgorithm(INT iAlgorithm);

PB_HMACSHA1(0), 
PB_HMACSHA224(1), 
PB_HMACSHA256(2), 
PB_HMACSHA384(3), 
PB_HMACSHA512(4), 
PB_HMACMD5(5), 
PB_HMACRIPEMD160(6), 
PB_SHA1(7), 
PB_MD5(8), 
PB_MD2(9)

int ipworksencrypt_pbkdf_getalgorithm(void* lpObj);
int ipworksencrypt_pbkdf_setalgorithm(void* lpObj, int iAlgorithm);

int GetAlgorithm();
int SetAlgorithm(int iAlgorithm);

Default Value

0

Remarks

This property specifies the algorithm used for the pseudo random function. Possible values are:

Note: When using PBDKF1 the maximum KeyLength value is 160 bits for SHA1, and 128 bits for MD2 and MD5.

Data Type

Integer

Iterations Property (PBKDF Class)

The number of iterations to perform.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetIterations();
int SetIterations(int iIterations);

Unicode (Windows)
INT GetIterations();
INT SetIterations(INT iIterations);

int ipworksencrypt_pbkdf_getiterations(void* lpObj);
int ipworksencrypt_pbkdf_setiterations(void* lpObj, int iIterations);

int GetIterations();
int SetIterations(int iIterations);

Default Value

10000

Remarks

This property specifies the number of iterations to perform when deriving the key. Larger values require more time to derive a key, however they also make password cracking more difficult by increasing the amount of time required to derive each key.

The recommended minimum number of iterations is 1000, and larger values such as 10,000 are common. The default value is 10000.

Data Type

Integer

Key Property (PBKDF Class)

The derived key.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetKey(char* &lpKey, int &lenKey);

Unicode (Windows)
INT GetKey(LPSTR &lpKey, INT &lenKey);

int ipworksencrypt_pbkdf_getkey(void* lpObj, char** lpKey, int* lenKey);

QByteArray GetKey();

Default Value

""

Remarks

This property holds the derived key. After calling CreateKey this property will be populated.

This property is read-only.

Data Type

Binary String

KeyLength Property (PBKDF Class)

The desired length in bits of the derived key.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetKeyLength();
int SetKeyLength(int iKeyLength);

Unicode (Windows)
INT GetKeyLength();
INT SetKeyLength(INT iKeyLength);

int ipworksencrypt_pbkdf_getkeylength(void* lpObj);
int ipworksencrypt_pbkdf_setkeylength(void* lpObj, int iKeyLength);

int GetKeyLength();
int SetKeyLength(int iKeyLength);

Default Value

1024

Remarks

This property specifies the length in bits of the Key.

The provided value must be divisible by 8. The default value is 1024.

Note: When Version is set to PBKDF1 certain restrictions apply. When Algorithm is set to MD5 the maximum length is 128. When Algorithm is set to SHA1 the maximum value is 160.

Data Type

Integer

Password Property (PBKDF Class)

The master password from which a derived key is generated.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetPassword(char* &lpPassword, int &lenPassword);
int SetPassword(const char* lpPassword, int lenPassword);

Unicode (Windows)
INT GetPassword(LPSTR &lpPassword, INT &lenPassword);
INT SetPassword(LPCSTR lpPassword, INT lenPassword);

int ipworksencrypt_pbkdf_getpassword(void* lpObj, char** lpPassword, int* lenPassword);
int ipworksencrypt_pbkdf_setpassword(void* lpObj, const char* lpPassword, int lenPassword);

QByteArray GetPassword();
int SetPassword(QByteArray qbaPassword);

Default Value

""

Remarks

This property specifies the password from which the derived key is created.

Data Type

Binary String

Salt Property (PBKDF Class)

The cryptographic salt.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetSalt(char* &lpSalt, int &lenSalt);
int SetSalt(const char* lpSalt, int lenSalt);

Unicode (Windows)
INT GetSalt(LPSTR &lpSalt, INT &lenSalt);
INT SetSalt(LPCSTR lpSalt, INT lenSalt);

int ipworksencrypt_pbkdf_getsalt(void* lpObj, char** lpSalt, int* lenSalt);
int ipworksencrypt_pbkdf_setsalt(void* lpObj, const char* lpSalt, int lenSalt);

QByteArray GetSalt();
int SetSalt(QByteArray qbaSalt);

Default Value

""

Remarks

This property specifies the salt used during key creation.

It is recommended to provide a salt value of at least 64 bits in length. A common length is 128 bits. It is also recommended that the salt value be randomly chosen.

Data Type

Binary String

UseHex Property (PBKDF Class)

Whether the key 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_pbkdf_getusehex(void* lpObj);
int ipworksencrypt_pbkdf_setusehex(void* lpObj, int bUseHex);

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

Default Value

FALSE

Remarks

This setting specifies whether the created Key is hex encoded when calling CreateKey. The default value is False.

Data Type

Boolean

Version Property (PBKDF Class)

The PBKDF version.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetVersion();
int SetVersion(int iVersion);

Unicode (Windows)
INT GetVersion();
INT SetVersion(INT iVersion);

V_PBKDF1(0), 
V_PBKDF2(1)

int ipworksencrypt_pbkdf_getversion(void* lpObj);
int ipworksencrypt_pbkdf_setversion(void* lpObj, int iVersion);

int GetVersion();
int SetVersion(int iVersion);

Default Value

1

Remarks

This property specifies the PBKDF version to be used. It is recommended to use PBKDF2 for new applications. PBKDF1 is included only for compatibility with existing applications and is not recommended.

Possible values are:

• 0 (vPBKDF1)
• 1 (vPBKDF2 - default)

Data Type

Integer

Config Method (PBKDF 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_pbkdf_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 (PBKDF Class)

Creates a key.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int CreateKey();

Unicode (Windows)
INT CreateKey();

int ipworksencrypt_pbkdf_createkey(void* lpObj);

int CreateKey();

Remarks

This method creates a key using a version of the Password-Based Key Derivation Function (PBKDF).

The following properties are applicable when calling this method:

• Password (required)
• Salt (required)
• Algorithm
• Iterations
• KeyLength
• Version

Code Example:

 
 Copy
Pbkdf pbkdf = new Pbkdf();
pbkdf.Password = "password";
pbkdf.Salt = "0123456789ABCDEF";
pbkdf.KeyLength = 4096;
pbkdf.CreateKey();
      
//Now do something with pbkdf.Key

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 (PBKDF Class)

Resets the class.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int Reset();

Unicode (Windows)
INT Reset();

int ipworksencrypt_pbkdf_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.)

Error Event (PBKDF Class)

Fired when information is available about errors during data delivery.

Syntax

• C++
• C
• Qt

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

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


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

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

#define EID_PBKDF_ERROR 1

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

class PBKDFErrorEventParams {
public:
  int ErrorCode();

  const QString &Description();

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

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

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

Remarks

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

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

Config Settings (PBKDF Class)

PBKDF Config Settings

 
 Copy
Pbkdf pw = new Pbkdf();
pw.Config("EncodeKey=true");
pw.Config("AllowEmptyPassword=true");
//pw.PasswordB = new byte[0];
pw.Password = "";
pw.Salt = "saltsalt";
pw.Iterations = 100;
pw.KeyLength = 160;
pw.Version = PbkdfVersions.vPBKDF2;
pw.Algorithm = PbkdfAlgorithms.pbHMACSHA1;
pw.CreateKey();

Base Config Settings

Trappable Errors (PBKDF 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.

PBKDF Errors