HMAC Component

Properties   Methods   Events   Config Settings   Errors  

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

Syntax

nsoftware.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

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

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

Input Notes

The component 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:

When a valid source is found the search stops.

After calling this method MACValue 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

ComputeMACBlock allows input to the component 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);

Property List

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

AlgorithmThe algorithm used to create the HMAC.
EncodeMACWhether the MAC value is hex encoded.
InputFileThe file to process.
InputMessageThe message to process.
KeyThe key to be used when computing a MAC (Message Authentication Code).
MACValueThe computed MAC value.

Method List

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

ComputeMACComputes the MAC.
ComputeMACBlockComputes the MAC value of specified data.
ConfigSets or retrieves a configuration setting.
ResetResets the component.
SetInputStreamSets the stream from which the component will read data.

Event List

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

ErrorFired when information is available about errors during data delivery.
ProgressFired as progress is made.

Config Settings

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

CloseInputStreamAfterProcessingDetermines whether or not the input stream is closed after processing.
BuildInfoInformation about the product's build.
GUIAvailableWhether or not a message loop is available for processing events.
LicenseInfoInformation about the current license.
MaskSensitiveDataWhether sensitive data is masked in log messages.
UseFIPSCompliantAPITells the component whether or not to use FIPS certified APIs.
UseInternalSecurityAPIWhether or not to use the system security libraries or an internal implementation.

Algorithm Property (HMAC Component)

The algorithm used to create the HMAC.

Syntax

public HMACAlgorithms Algorithm { get; set; }

enum HMACAlgorithms {
  hmacMD5,
  hmacSHA1,
  hmacSHA224,
  hmacSHA256,
  hmacSHA384,
  hmacSHA512,
  hmacRIPEMD160
}

Public Property Algorithm As HmacAlgorithms

Enum HMACAlgorithms
  hmacMD5
  hmacSHA1
  hmacSHA224
  hmacSHA256
  hmacSHA384
  hmacSHA512
  hmacRIPEMD160
End Enum

Default Value

3

Remarks

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

0 (hmacMD5) HMAC-MD5
1 (hmacSHA1) HMAC-SHA1
2 (hmacSHA224) HMAC-SHA224
3 (hmacSHA256) HMAC-SHA256
4 (hmacSHA384) HMAC-SHA384
5 (hmacSHA512) HMAC-SHA512
6 (hmacRIPEMD160) HMAC-RIPEMD-160

EncodeMAC Property (HMAC Component)

Whether the MAC value is hex encoded.

Syntax

public bool EncodeMAC { get; set; }

Public Property EncodeMAC As Boolean

Default Value

True

Remarks

This property specifies whether the computed MAC value is hex encoded. When set to True (default) the component 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.

InputFile Property (HMAC Component)

The file to process.

Syntax

public string InputFile { get; set; }

Public Property InputFile As String

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 component 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:

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.

InputMessage Property (HMAC Component)

The message to process.

Syntax

public string InputMessage { get; set; }
public byte[] InputMessageB { get; set; }

Public Property InputMessage As String
Public Property InputMessageB As Byte()

Default Value

""

Remarks

This property specifies the message to be processed.

Input and Output Properties

The component 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:

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 Property (HMAC Component)

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

Syntax

public string Key { get; set; }
public byte[] KeyB { get; set; }

Public Property Key As String
Public Property KeyB As Byte()

Default Value

""

Remarks

This property holds the secret key used when computing the MACValue. 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)

SHA1SHA224SHA256SHA384SHA512MD5RIPEMD160
Recommended Key Size20 28 32 48 64 16 20
Hash Size 20 28 32 48 64 16 20
Block Size 64 64 64 128 128 64 64

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.

MACValue Property (HMAC Component)

The computed MAC value.

Syntax

public string MACValue { get; }
public byte[] MACValueB { get; }

Public ReadOnly Property MACValue As String
Public ReadOnly Property MACValueB As Byte()

Default Value

""

Remarks

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

This property is read-only.

ComputeMAC Method (HMAC Component)

Computes the MAC.

Syntax

public void ComputeMAC();

Async Version
public async Task ComputeMAC();
public async Task ComputeMAC(CancellationToken cancellationToken);

Public Sub ComputeMAC()

Async Version
Public Sub ComputeMAC() As Task
Public Sub ComputeMAC(cancellationToken As CancellationToken) As Task

Remarks

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

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

Input Notes

The component 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:

When a valid source is found the search stops.

After calling this method MACValue 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 Method (HMAC Component)

Computes the MAC value of specified data.

Syntax

public byte[] ComputeMACBlock(byte[] inputBuffer, bool lastBlock);

Async Version
public async Task<byte[]> ComputeMACBlock(byte[] inputBuffer, bool lastBlock);
public async Task<byte[]> ComputeMACBlock(byte[] inputBuffer, bool lastBlock, CancellationToken cancellationToken);

Public Function ComputeMACBlock(ByVal InputBuffer As Byte(), ByVal LastBlock As Boolean) As Byte()

Async Version
Public Function ComputeMACBlock(ByVal InputBuffer As Byte(), ByVal LastBlock As Boolean) As Task(Of Byte())
Public Function ComputeMACBlock(ByVal InputBuffer As Byte(), ByVal LastBlock As Boolean, cancellationToken As CancellationToken) As Task(Of Byte())

Remarks

ComputeMACBlock allows input to the component 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 Component)

Sets or retrieves a configuration setting.

Syntax

public string Config(string configurationString);

Async Version
public async Task<string> Config(string configurationString);
public async Task<string> Config(string configurationString, CancellationToken cancellationToken);

Public Function Config(ByVal ConfigurationString As String) As String

Async Version
Public Function Config(ByVal ConfigurationString As String) As Task(Of String)
Public Function Config(ByVal ConfigurationString As String, cancellationToken As CancellationToken) As Task(Of String)

Remarks

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

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

Resets the component.

Syntax

public void Reset();

Async Version
public async Task Reset();
public async Task Reset(CancellationToken cancellationToken);

Public Sub Reset()

Async Version
Public Sub Reset() As Task
Public Sub Reset(cancellationToken As CancellationToken) As Task

Remarks

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

SetInputStream Method (HMAC Component)

Sets the stream from which the component will read data.

Syntax

public void SetInputStream(System.IO.Stream inputStream);

Async Version
public async Task SetInputStream(System.IO.Stream inputStream);
public async Task SetInputStream(System.IO.Stream inputStream, CancellationToken cancellationToken);

Public Sub SetInputStream(ByVal InputStream As System.IO.Stream)

Async Version
Public Sub SetInputStream(ByVal InputStream As System.IO.Stream) As Task
Public Sub SetInputStream(ByVal InputStream As System.IO.Stream, cancellationToken As CancellationToken) As Task

Remarks

This method sets the stream from which the component will read data.

Input Notes

The component 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:

When a valid source is found the search stops.

Error Event (HMAC Component)

Fired when information is available about errors during data delivery.

Syntax

public event OnErrorHandler OnError;

public delegate void OnErrorHandler(object sender, HMACErrorEventArgs e);

public class HMACErrorEventArgs : EventArgs {
  public int ErrorCode { get; }
  public string Description { get; }
}

Public Event OnError As OnErrorHandler

Public Delegate Sub OnErrorHandler(sender As Object, e As HMACErrorEventArgs)

Public Class HMACErrorEventArgs Inherits EventArgs
  Public ReadOnly Property ErrorCode As Integer
  Public ReadOnly Property Description As String
End Class

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the component throws an exception.

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.

Progress Event (HMAC Component)

Fired as progress is made.

Syntax

public event OnProgressHandler OnProgress;

public delegate void OnProgressHandler(object sender, HMACProgressEventArgs e);

public class HMACProgressEventArgs : EventArgs {
  public long BytesProcessed { get; }
  public int PercentProcessed { get; }
}

Public Event OnProgress As OnProgressHandler

Public Delegate Sub OnProgressHandler(sender As Object, e As HMACProgressEventArgs)

Public Class HMACProgressEventArgs Inherits EventArgs
  Public ReadOnly Property BytesProcessed As Long
  Public ReadOnly Property PercentProcessed As Integer
End Class

Remarks

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

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 Component)

The component 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 component, access to these internal properties is provided through the Config method.

HMAC Config Settings

CloseInputStreamAfterProcessing:   Determines whether or not the input stream is closed after processing.

Determines whether or not the input stream set by SetInputStream is closed after processing is complete. The default value is True.

Base Config Settings

BuildInfo:   Information about the product's build.

When queried, this setting will return a string containing information about the product's build.

GUIAvailable:   Whether or not a message loop is available for processing events.

In a GUI-based application, long-running blocking operations may cause the application to stop responding to input until the operation returns. The component will attempt to discover whether or not the application has a message loop and, if one is discovered, it will process events in that message loop during any such blocking operation.

In some non-GUI applications, an invalid message loop may be discovered that will result in errant behavior. In these cases, setting GUIAvailable to false will ensure that the component does not attempt to process external events.

LicenseInfo:   Information about the current license.

When queried, this setting will return a string containing information about the license this instance of a component is using. It will return the following information:

  • Product: The product the license is for.
  • Product Key: The key the license was generated from.
  • License Source: Where the license was found (e.g., RuntimeLicense, License File).
  • License Type: The type of license installed (e.g., Royalty Free, Single Server).
  • Last Valid Build: The last valid build number for which the license will work.
MaskSensitiveData:   Whether sensitive data is masked in log messages.

In certain circumstances it may be beneficial to mask sensitive data, like passwords, in log messages. Set this to true to mask sensitive data. The default is true.

UseFIPSCompliantAPI:   Tells the component whether or not to use FIPS certified APIs.

When set to true, the component will utilize the underlying operating system's certified APIs. Java editions, regardless of OS, utilize Bouncy Castle Federal Information Processing Standards (FIPS), while all other Windows editions make use of Microsoft security libraries.

FIPS mode can be enabled by setting the UseFIPSCompliantAPI configuration setting to true. This is a static setting that applies to all instances of all components of the toolkit within the process. It is recommended to enable or disable this setting once before the component has been used to establish a connection. Enabling FIPS while an instance of the component is active and connected may result in unexpected behavior.

For more details, please see the FIPS 140-2 Compliance article.

NOTE: This setting is applicable only on Windows.

NOTE: Enabling FIPS compliance requires a special license; please contact sales@nsoftware.com for details.

UseInternalSecurityAPI:   Whether or not to use the system security libraries or an internal implementation.

When set to false, the component will use the system security libraries by default to perform cryptographic functions where applicable. In this case, calls to unmanaged code will be made. In certain environments, this is not desirable. To use a completely managed security implementation, set this setting to true.

Setting this configuration setting to true tells the component to use the internal implementation instead of using the system security libraries.

On Windows, this setting is set to false by default. On Linux/macOS, this setting is set to true by default.

NOTE: This setting is static. The value set is applicable to all components used in the application.

When this value is set, the product's system dynamic link library (DLL) is no longer required as a reference, as all unmanaged code is stored in that file.

Trappable Errors (HMAC Component)

HMAC Errors

104   Cannot read or write file.
108   Invalid key size.
304   Cannot write file.
305   Cannot read file.