Struct ipworksencrypt::HMAC

Properties   Methods   Events   Config Settings   Errors  

The HMAC struct may be used to produce a MAC (or Tag) value using the HMAC algorithm.

Syntax

ipworksencrypt::HMAC

Remarks

The HMAC component allows you to compute a MAC value using various algorithms including HMACMD5, HMACSHA1, HMACSHA224, HMACSHA256, HMACSHA384, HMACSHA512, etc.

ComputeMAC Notes

compute_mac computes the MAC (Message Authentication Code) from the input data.

Before calling this method set key to a key. If encode_mac is set to True (default) the output data will be hex encoded.

Input Notes

The struct will determine the source of the input based on which properties are set.

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

• input_file
• input_message

When a valid source is found the search stops.

After calling this method mac_value will be populated with the computed MAC value.

ComputeMAC Example

HMAC hmac = new HMAC(); hmac.Algorithm = HMACAlgorithms.hmacSHA256; hmac.KeyB = new byte[] { 0x1c, 0x92, 0x40, 0xa5, 0xeb, 0x55, 0xd3, 0x8a, 0xf3, 0x33, 0x88, 0x86, 0x04, 0xf6, 0xb5, 0xf0, 0x47, 0x39, 0x17, 0xc1, 0x40, 0x2b, 0x80, 0x09, 0x9d, 0xca, 0x5c, 0xbc, 0x20, 0x70, 0x75, 0xc0 }; hmac.InputMessage = "Hello HMAC"; hmac.EncodeMAC = true; //hex output hmac.ComputeMAC(); //This outputs "FDFB2DD7121E743D933718E165659A46DF431CFBCCDEA121C68CE13EA83153B3" Console.WriteLine(hmac.MACValue);

ComputeMACBlock Notes

compute_mac_block allows input to the struct to be specified in blocks. This method will return the MAC value only when the parameter LastBlock is True.

InputBuffer specifies the input data.

LastBlock specifies whether the block is the last block. If this is False the method will return an empty byte array.

To calculate the MAC value of data that is broken apart into multiple blocks make multiple calls to this method. For instance: //Encode output in hex hmac.EncodeMAC = true; //hex output //Pass any number of parts, of any size hmac.ComputeMACBlock(part1,false); hmac.ComputeMACBlock(part2,false); hmac.ComputeMACBlock(part3,false); //Pass true for the last block hmac.ComputeMACBlock(lastPart,true); //The MACValue property holds the MAC value Console.WriteLine(hmac.MACValue);

Object Lifetime

The new() method returns a mutable reference to a struct instance. The object itself is kept in the global list maintained by IPWorksEncrypt. Due to this, the HMAC struct cannot be disposed of automatically. Please, call the dispose(&mut self) method of HMAC when you have finished using the instance.

Property List

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

Method List

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

Event List

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

Config Settings

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

algorithm property (HMAC Struct)

The algorithm used to create the HMAC.

Syntax

fn algorithm(&self ) -> Result<i32, IPWorksEncryptError> 
fn set_algorithm(&self, value : i32) ->  Option<IPWorksEncryptError> 

Possible Values

0   // MD5
1   // SHA1
2   // SHA224
3   // SHA256
4   // SHA384
5   // SHA512
6   // RIPEMD160

Default Value

3

Remarks

This property specifies the algorithm used when calling compute_mac. Possible values are:

Data Type

i32

encode_mac property (HMAC Struct)

Whether the MAC value is hex encoded.

Syntax

fn encode_mac(&self ) -> Result<bool, IPWorksEncryptError> 
fn set_encode_mac(&self, value : bool) ->  Option<IPWorksEncryptError> 

Default Value

true

Remarks

This property specifies whether the computed MAC value is hex encoded. When set to True (default) the struct will hex encode the computed MAC for easier use. Set this value to False to obtain the MAC value in an unmodified form.

The default value is True.

Data Type

bool

input_file property (HMAC Struct)

The file to process.

Syntax

fn input_file(&self ) -> Result<String, IPWorksEncryptError> 
fn set_input_file(&self, value : &str) ->  Option<IPWorksEncryptError> 
fn set_input_file_ref(&self, value : &String) ->  Option<IPWorksEncryptError> 

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 struct 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:

• input_file
• input_message

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

• output_file
• output_message: The output data is written to this property if no other destination is specified.

Data Type

String

input_message property (HMAC Struct)

The message to process.

Syntax

fn input_message(&self ) -> Result<Vec<u8>, IPWorksEncryptError> 
fn set_input_message(&self, value : Vec<u8>) ->  Option<IPWorksEncryptError> 
fn set_input_message_ref(&self, value : &[u8]) ->  Option<IPWorksEncryptError> 

Default Value

""

Remarks

This property specifies the message to be processed.

Input and Output Properties

The struct 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:

• input_file
• input_message

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

• output_file
• output_message: The output data is written to this property if no other destination is specified.

Data Type

Vec

key property (HMAC Struct)

The key to be used when computing a MAC (Message Authentication Code).

Syntax

fn key(&self ) -> Result<Vec<u8>, IPWorksEncryptError> 
fn set_key(&self, value : Vec<u8>) ->  Option<IPWorksEncryptError> 
fn set_key_ref(&self, value : &[u8]) ->  Option<IPWorksEncryptError> 

Default Value

""

Remarks

This property holds the secret key used when computing the mac_value. The key can be arbitrarily long.

It is recommended that the length of the key be equal to or larger than the hash size of the algorithm. Use of keys shorter than the hash size is discouraged.

Sizes (in bytes)

Key Length Details

As mentioned above it is recommended to use a key size equal to the hash size. Use of keys larger than the hash size does not typically significantly increase the function strength. Keys of any length are technically valid however see the below processing rules to understand how keys of varying lengths are treated:

• If the key length is equal to the hash size (recommended) it is used without modification.
• If the key length is less than the hash size it is used without modification.
• If the key length is less than or equal to the block size it is used without modification.
• If the key length is larger than the block size it is first hashed with the same algorithm.

Data Type

Vec

mac_value property (HMAC Struct)

The computed MAC value.

Syntax

fn mac_value(&self ) -> Result<Vec<u8>, IPWorksEncryptError> 

Default Value

""

Remarks

The computed MAC value. This property is populated after calling compute_mac.

This property is read-only.

Data Type

Vec

compute_mac method (HMAC Struct)

Computes the MAC.

Syntax

fn compute_mac(&self) -> Result<(), IPWorksEncryptError>

Remarks

compute_mac computes the MAC (Message Authentication Code) from the input data.

Before calling this method set key to a key. If encode_mac is set to True (default) the output data will be hex encoded.

Input Notes

The struct will determine the source of the input based on which properties are set.

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

• input_file
• input_message

When a valid source is found the search stops.

After calling this method mac_value will be populated with the computed MAC value.

ComputeMAC Example

HMAC hmac = new HMAC(); hmac.Algorithm = HMACAlgorithms.hmacSHA256; hmac.KeyB = new byte[] { 0x1c, 0x92, 0x40, 0xa5, 0xeb, 0x55, 0xd3, 0x8a, 0xf3, 0x33, 0x88, 0x86, 0x04, 0xf6, 0xb5, 0xf0, 0x47, 0x39, 0x17, 0xc1, 0x40, 0x2b, 0x80, 0x09, 0x9d, 0xca, 0x5c, 0xbc, 0x20, 0x70, 0x75, 0xc0 }; hmac.InputMessage = "Hello HMAC"; hmac.EncodeMAC = true; //hex output hmac.ComputeMAC(); //This outputs "FDFB2DD7121E743D933718E165659A46DF431CFBCCDEA121C68CE13EA83153B3" Console.WriteLine(hmac.MACValue);

compute_mac_block method (HMAC Struct)

Computes the MAC value of specified data.

Syntax

fn compute_mac_block(&self, input_buffer : &[u8], last_block : bool) ->  Result<Vec<u8>, IPWorksEncryptError>

Remarks

compute_mac_block allows input to the struct to be specified in blocks. This method will return the MAC value only when the parameter LastBlock is True.

InputBuffer specifies the input data.

LastBlock specifies whether the block is the last block. If this is False the method will return an empty byte array.

To calculate the MAC value of data that is broken apart into multiple blocks make multiple calls to this method. For instance: //Encode output in hex hmac.EncodeMAC = true; //hex output //Pass any number of parts, of any size hmac.ComputeMACBlock(part1,false); hmac.ComputeMACBlock(part2,false); hmac.ComputeMACBlock(part3,false); //Pass true for the last block hmac.ComputeMACBlock(lastPart,true); //The MACValue property holds the MAC value Console.WriteLine(hmac.MACValue);

config method (HMAC Struct)

Sets or retrieves a configuration setting.

Syntax

fn config(&self, configuration_string : &str) ->  Result<String, IPWorksEncryptError>

Remarks

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

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the struct, 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.

reset method (HMAC Struct)

Resets the struct.

Syntax

fn reset(&self) -> Result<(), IPWorksEncryptError>

Remarks

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

on_error event (HMAC Struct)

Fired when information is available about errors during data delivery.

Syntax

// HMACErrorEventArgs carries the HMAC Error event's parameters.
pub struct HMACErrorEventArgs {
  fn error_code(&self) -> i32
  fn description(&self) -> &String
}

// HMACErrorEvent defines the signature of the HMAC Error event's handler function.
pub trait HMACErrorEvent {
  fn on_error(&self, sender : HMAC, e : &mut HMACErrorEventArgs);
}

impl <'a> HMAC<'a> {
  pub fn on_error(&self) -> &'a dyn HMACErrorEvent;
  pub fn set_on_error(&mut self, value : &'a dyn HMACErrorEvent);
  ...
}

Remarks

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

The error_code 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.

on_progress event (HMAC Struct)

Fired as progress is made.

Syntax

// HMACProgressEventArgs carries the HMAC Progress event's parameters.
pub struct HMACProgressEventArgs {
  fn bytes_processed(&self) -> i64
  fn percent_processed(&self) -> i32
}

// HMACProgressEvent defines the signature of the HMAC Progress event's handler function.
pub trait HMACProgressEvent {
  fn on_progress(&self, sender : HMAC, e : &mut HMACProgressEventArgs);
}

impl <'a> HMAC<'a> {
  pub fn on_progress(&self) -> &'a dyn HMACProgressEvent;
  pub fn set_on_progress(&mut self, value : &'a dyn HMACProgressEvent);
  ...
}

Remarks

This event is fired automatically as data is processed by the struct.

The PercentProcessed parameter indicates the current status of the operation.

The BytesProcessed parameter holds the total number of bytes processed so far.

Config Settings (HMAC Struct)

The struct accepts one or more of the following configuration settings. Configuration settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the struct, access to these internal properties is provided through the config method.

Base Config Settings

Trappable Errors (HMAC Struct)

HMAC Errors