PBKDF Module

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

Syntax

IPWorksEncrypt.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: 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 module with short descriptions. Click on the links for further details.

Method List

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

Event List

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

Config Settings

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

Algorithm Property (PBKDF Module)

The underlying pseudorandom function.

Syntax

• Swift
• Objective-C

public var algorithm: PBKDFAlgorithms {
  get {...}
  set {...}
}

public enum PBKDFAlgorithms: Int32 {
  case pbHMACSHA1 = 0
  case pbHMACSHA224 = 1
  case pbHMACSHA256 = 2
  case pbHMACSHA384 = 3
  case pbHMACSHA512 = 4
  case pbHMACMD5 = 5
  case pbHMACRIPEMD160 = 6
  case pbSHA1 = 7
  case pbMD5 = 8
  case pbMD2 = 9
}

@property (nonatomic,readwrite,assign,getter=algorithm,setter=setAlgorithm:) int algorithm;

- (int)algorithm;
- (void)setAlgorithm :(int)newAlgorithm;

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.

Iterations Property (PBKDF Module)

The number of iterations to perform.

Syntax

• Swift
• Objective-C

public var iterations: Int32 {
  get {...}
  set {...}
}

@property (nonatomic,readwrite,assign,getter=iterations,setter=setIterations:) int iterations;

- (int)iterations;
- (void)setIterations :(int)newIterations;

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.

Key Property (PBKDF Module)

The derived key.

Syntax

• Swift
• Objective-C

public var key: String {
  get {...}
}

public var keyB: Data {
  get {...}
}

@property (nonatomic,readonly,assign,getter=key) NSString* key;

- (NSString*)key;

@property (nonatomic,readonly,assign,getter=keyB) NSData* keyB;

- (NSData*)keyB;

Default Value

""

Remarks

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

This property is read-only.

KeyLength Property (PBKDF Module)

The desired length in bits of the derived key.

Syntax

• Swift
• Objective-C

public var keyLength: Int32 {
  get {...}
  set {...}
}

@property (nonatomic,readwrite,assign,getter=keyLength,setter=setKeyLength:) int keyLength;

- (int)keyLength;
- (void)setKeyLength :(int)newKeyLength;

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.

Password Property (PBKDF Module)

The password from which a derived key is generated.

Syntax

• Swift
• Objective-C

public var password: String {
  get {...}
  set {...}
}

public var passwordB: Data {
  get {...}
  set {...}
}

@property (nonatomic,readwrite,assign,getter=password,setter=setPassword:) NSString* password;

- (NSString*)password;
- (void)setPassword :(NSString*)newPassword;

@property (nonatomic,readwrite,assign,getter=passwordB,setter=setPasswordB:) NSData* passwordB;

- (NSData*)passwordB;
- (void)setPasswordB :(NSData*)newPassword;

Default Value

""

Remarks

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

Salt Property (PBKDF Module)

The cryptographic salt.

Syntax

• Swift
• Objective-C

public var salt: String {
  get {...}
  set {...}
}

public var saltB: Data {
  get {...}
  set {...}
}

@property (nonatomic,readwrite,assign,getter=salt,setter=setSalt:) NSString* salt;

- (NSString*)salt;
- (void)setSalt :(NSString*)newSalt;

@property (nonatomic,readwrite,assign,getter=saltB,setter=setSaltB:) NSData* saltB;

- (NSData*)saltB;
- (void)setSaltB :(NSData*)newSalt;

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.

UseHex Property (PBKDF Module)

Whether the key is hex encoded.

Syntax

• Swift
• Objective-C

public var useHex: Bool {
  get {...}
  set {...}
}

@property (nonatomic,readwrite,assign,getter=useHex,setter=setUseHex:) BOOL useHex;

- (BOOL)useHex;
- (void)setUseHex :(BOOL)newUseHex;

Default Value

False

Remarks

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

Version Property (PBKDF Module)

The PBKDF version.

Syntax

• Swift
• Objective-C

public var version: PBKDFVersions {
  get {...}
  set {...}
}

public enum PBKDFVersions: Int32 {
  case vPBKDF1 = 0
  case vPBKDF2 = 1
}

@property (nonatomic,readwrite,assign,getter=version,setter=setVersion:) int version;

- (int)version;
- (void)setVersion :(int)newVersion;

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)

Config Method (PBKDF Module)

Sets or retrieves a configuration setting.

Syntax

• Swift
• Objective-C

public func config(configurationString: String) throws -> String

- (NSString*)config:(NSString*)configurationString;

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.

CreateKey Method (PBKDF Module)

Creates a key.

Syntax

• Swift
• Objective-C

public func createKey() throws -> Void

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

Reset Method (PBKDF Module)

Resets the component.

Syntax

• Swift
• Objective-C

public func reset() throws -> Void

- (void)reset;

Remarks

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

Error Event (PBKDF Module)

Fired when information is available about errors during data delivery.

Syntax

• Swift
• Objective-C

func onError(errorCode: Int32, description: String)

- (void)onError:(int)errorCode :(NSString*)description;

Remarks

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

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 Module)

PBKDF Config Settings

Base Config Settings

Trappable Errors (PBKDF Module)

PBKDF Errors