# CMAC Class

The CMAC class may be used to produce a MAC (or Tag) value using the AES CMAC algorithm.

## Syntax

```text
ipworksencrypt.CMAC
```

## Remarks

The CMAC class implements the AES CMAC algorithm defined in RFC 4493. This may be used to compute a MAC (or Tag) value on data of any length.

The [Key](#key-property-cmac-class) must be set to a 128-bit (16 bytes), 192-bit (24 bytes), or 256-bit (32 bytes) key before computing the MAC. The computed MAC is 128-bit (16 bytes) in size.

**ComputeMAC Notes**

[ComputeMAC](#computemac-method-cmac-class) computes the MAC (Message Authentication Code) from the input data.

Before calling this method set [Key](#key-property-cmac-class) to a 128-bit (16 bytes), 192-bit (24 bytes), or 256-bit (32 bytes) key. If [EncodeMAC](#encodemac-property-cmac-class) is set to True (default) the output data will be hex encoded.

**Input Notes**

The class 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:

- [SetInputStream](#setinputstream-method-cmac-class)
- [InputFile](#inputfile-property-cmac-class)
- [InputMessage](#inputmessage-property-cmac-class)

 When a valid source is found the search stops.

After calling this method [MACValue](#macvalue-property-cmac-class) will be populated with the computed 128 bit (16 byte) value.

**ComputeMAC Example**

```csharp
CMAC cmac = new CMAC();
cmac.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 };
cmac.InputMessage = "Hello CMAC";
cmac.EncodeMAC = true; //hex output
cmac.ComputeMAC();

//This outputs "1234E6C7808BF17C1CBD951D1A139E4D"
Console.WriteLine(cmac.MACValue);
```

**ComputeMACBlock Notes**

[ComputeMACBlock](#computemacblock-method-cmac-class) allows input to the class 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:

```text
//Encode output in hex
cmac.EncodeMAC = true; //hex output

//Pass any number of parts, of any size
cmac.ComputeMACBlock(part1,false);
cmac.ComputeMACBlock(part2,false);
cmac.ComputeMACBlock(part3,false);

//Pass true for the last block
cmac.ComputeMACBlock(lastPart,true);

//The MACValue property holds the MAC value
Console.WriteLine(cmac.MACValue);
```

## Property List

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

|  |  |
| --- | --- |
| [EncodeMAC](#encodemac-property-cmac-class) | Whether the MAC value is hex encoded. |
| [InputFile](#inputfile-property-cmac-class) | The file to process. |
| [InputMessage](#inputmessage-property-cmac-class) | The message to process. |
| [Key](#key-property-cmac-class) | The key to be used when computing a MAC (Message Authentication Code). |
| [MACValue](#macvalue-property-cmac-class) | The computed MAC value. |

## Method List

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

|  |  |
| --- | --- |
| [ComputeMAC](#computemac-method-cmac-class) | Computes the MAC. |
| [ComputeMACBlock](#computemacblock-method-cmac-class) | Computes the MAC value of specified data. |
| [Config](#config-method-cmac-class) | Sets or retrieves a configuration setting. |
| [Reset](#reset-method-cmac-class) | Resets the class. |
| [SetInputStream](#setinputstream-method-cmac-class) | Sets the stream from which the class will read data. |

## 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.*

|  |  |
| --- | --- |
| [Error](#error-event-cmac-class) | Fired when information is available about errors during data delivery. |
| [Progress](#progress-event-cmac-class) | Fired as progress is made. |

## Config Settings

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

|  |  |
| --- | --- |
| [CloseInputStreamAfterProcessing](#CloseInputStreamAfterProcessing) | Determines whether or not the input stream is closed after processing. |
| [BuildInfo](#BuildInfo) | Information about the product's build. |
| [GUIAvailable](#GUIAvailable) | Whether or not a message loop is available for processing events. |
| [LicenseInfo](#LicenseInfo) | Information about the current license. |
| [MaskSensitiveData](#MaskSensitiveData) | Whether sensitive data is masked in log messages. |
| [UseDaemonThreads](#UseDaemonThreads) | Whether threads created by the class are daemon threads. |
| [UseFIPSCompliantAPI](#UseFIPSCompliantAPI) | Tells the class whether or not to use FIPS certified APIs. |
| [UseInternalSecurityAPI](#UseInternalSecurityAPI) | Whether or not to use the system security libraries or an internal implementation. |
| [UseVirtualThreads](#UseVirtualThreads) | Whether threads created by the class use virtual threads instead of platform threads. |

# EncodeMAC Property ([CMAC](#cmac-class) Class)

Whether the MAC value is hex encoded.

## Syntax

```text
public boolean isEncodeMAC();
public void setEncodeMAC(boolean encodeMAC);
```

## Default Value

True

## Remarks

This property specifies whether the computed MAC value is hex encoded. When set to True (default) the class 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 ([CMAC](#cmac-class) Class)

The file to process.

## Syntax

```text
public String getInputFile();
public void setInputFile(String inputFile);
```

## 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](#setinputstream-method-cmac-class)
- InputFile
- [InputMessage](#inputmessage-property-cmac-class)

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](#CloseInputStreamAfterProcessing) or [CloseOutputStreamAfterProcessing](#CloseOutputStreamAfterProcessing).

# InputMessage Property ([CMAC](#cmac-class) Class)

The message to process.

## Syntax

```text
public byte[] getInputMessage();
public void setInputMessage(byte[] inputMessage);
```

## 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](#setinputstream-method-cmac-class)
- [InputFile](#inputfile-property-cmac-class)
- 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](#CloseInputStreamAfterProcessing) or [CloseOutputStreamAfterProcessing](#CloseOutputStreamAfterProcessing).

# Key Property ([CMAC](#cmac-class) Class)

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

## Syntax

```text
public byte[] getKey();
public void setKey(byte[] key);
```

## Default Value

""

## Remarks

This property holds the secret key used when computing the [MACValue](#macvalue-property-cmac-class). The key must be 128-bit (16 bytes), 192-bit (24 bytes), or 256-bit (32 bytes) long.

# MACValue Property ([CMAC](#cmac-class) Class)

The computed MAC value.

## Syntax

```text
public byte[] getMACValue();
```

## Default Value

""

## Remarks

The 128 bit (16 byte) MAC value calculated after calling [ComputeMAC](#computemac-method-cmac-class).

This property is read-only.

# ComputeMAC Method ([CMAC](#cmac-class) Class)

Computes the MAC.

## Syntax

```text
public void computeMAC();
```

## Remarks

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

Before calling this method set [Key](#key-property-cmac-class) to a 128-bit (16 bytes), 192-bit (24 bytes), or 256-bit (32 bytes) key. If [EncodeMAC](#encodemac-property-cmac-class) is set to True (default) the output data will be hex encoded.

**Input Notes**

The class 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:

- [SetInputStream](#setinputstream-method-cmac-class)
- [InputFile](#inputfile-property-cmac-class)
- [InputMessage](#inputmessage-property-cmac-class)

 When a valid source is found the search stops.

After calling this method [MACValue](#macvalue-property-cmac-class) will be populated with the computed 128 bit (16 byte) value.

**ComputeMAC Example**

```csharp
CMAC cmac = new CMAC();
cmac.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 };
cmac.InputMessage = "Hello CMAC";
cmac.EncodeMAC = true; //hex output
cmac.ComputeMAC();

//This outputs "1234E6C7808BF17C1CBD951D1A139E4D"
Console.WriteLine(cmac.MACValue);
```

# ComputeMACBlock Method ([CMAC](#cmac-class) Class)

Computes the MAC value of specified data.

## Syntax

```text
public byte[] computeMACBlock(byte[] inputBuffer, boolean lastBlock);
```

## Remarks

ComputeMACBlock allows input to the class 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:

```text
//Encode output in hex
cmac.EncodeMAC = true; //hex output

//Pass any number of parts, of any size
cmac.ComputeMACBlock(part1,false);
cmac.ComputeMACBlock(part2,false);
cmac.ComputeMACBlock(part3,false);

//Pass true for the last block
cmac.ComputeMACBlock(lastPart,true);

//The MACValue property holds the MAC value
Console.WriteLine(cmac.MACValue);
```

# Config Method ([CMAC](#cmac-class) Class)

Sets or retrieves a configuration setting.

## Syntax

```text
public String config(String configurationString);
```

## Remarks

Config is a generic method available in every class. It is used to set and retrieve [configuration settings](#config-settings-cmac-class) 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](#config-settings-cmac-class), you must call *Config("PROPERTY")*. The value will be returned as a string.

# Reset Method ([CMAC](#cmac-class) Class)

Resets the class.

## Syntax

```text
public void reset();
```

## Remarks

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

# SetInputStream Method ([CMAC](#cmac-class) Class)

Sets the stream from which the class will read data.

## Syntax

```text
public void setInputStream(java.io.InputStream inputStream);
```

## Remarks

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

**Input Notes**

The class 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:

- SetInputStream
- [InputFile](#inputfile-property-cmac-class)
- [InputMessage](#inputmessage-property-cmac-class)

 When a valid source is found the search stops.

# Error Event ([CMAC](#cmac-class) Class)

Fired when information is available about errors during data delivery.

## Syntax

```text
public class DefaultCMACEventListener implements CMACEventListener {
  ...
  public void error(CMACErrorEvent e) {}
  ...
}

public class CMACErrorEvent {
  public int errorCode;
  public String description;
}
```

## Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the class 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](#trappable-errors-cmac-class) section.

# Progress Event ([CMAC](#cmac-class) Class)

Fired as progress is made.

## Syntax

```text
public class DefaultCMACEventListener implements CMACEventListener {
  ...
  public void progress(CMACProgressEvent e) {}
  ...
}

public class CMACProgressEvent {
  public long bytesProcessed;
  public int percentProcessed;
}
```

## Remarks

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

The *PercentProcessed* parameter indicates the current status of the operation.

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

# Config Settings ([CMAC](#cmac-class) Class)

 The class 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 class, access to these *internal properties* is provided through the [Config](#config-method-cmac-class) method.

### CMAC Config Settings

**CloseInputStreamAfterProcessing**: Determines whether or not the input stream is closed after processing.Determines whether or not the input stream set by [SetInputStream](#setinputstream-method-cmac-class) 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 class 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](#GUIAvailable) to *false* will ensure that the class 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 class 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*.

**UseDaemonThreads**: Whether threads created by the class are daemon threads.If set to True (default), when the class creates a thread, the thread's Daemon property will be explicitly set to True. When set to False, the class will not set the Daemon property on the created thread. The default value is True.

**UseFIPSCompliantAPI**: Tells the class whether or not to use FIPS certified APIs.When set to *true*, the class 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.

The Java edition requires installation of the FIPS-certified Bouncy Castle library regardless of the target operating system. This can be downloaded from [https://www.bouncycastle.org/fips-java/](https://www.bouncycastle.org/fips-java/). Only the "Provider" library is needed. The jar file should then be installed in a JRE search path.

The following classes must be imported in the application in which the component will be used:

```text
import java.security.Security;
import org.bouncycastle.jcajce.provider.BouncyCastleFipsProvider;
```

The Bouncy Castle provider must be added as a valid provider and must also be configured to operate in FIPS mode:

```text
System.setProperty("org.bouncycastle.fips.approved_only","true");
Security.addProvider(new BouncyCastleFipsProvider());
```

When [UseFIPSCompliantAPI](#UseFIPSCompliantAPI) is *true*, Secure Sockets Layer (SSL)-enabled classes can optionally be configured to use the Transport Layer Security (TLS) Bouncy Castle library. When SSLProvider is set to *sslpAutomatic* (default) or *sslpInternal*, an internal TLS implementation is used, but all cryptographic operations are offloaded to the Bouncy Castle FIPS provider to achieve FIPS-compliant operation. If SSLProvider is set to *sslpPlatform*, the Bouncy Castle JSSE will be used in place of the internal TLS implementation.

To enable the use of the Bouncy Castle JSSE take the following steps in addition to the steps above. Both the Bouncy Castle FIPS provider and the Bouncy Castle JSSE must be configured to use the Bouncy Castle TLS library in FIPS mode. Obtain the Bouncy Castle TLS library from [https://www.bouncycastle.org/fips-java/](https://www.bouncycastle.org/fips-java/). The jar file should then be installed in a JRE search path.

The following classes must be imported in the application in which the component will be used:

```text
import java.security.Security;
import org.bouncycastle.jcajce.provider.BouncyCastleFipsProvider;

//required to use BCJSSE when SSLProvider is set to sslpPlatform
import org.bouncycastle.jsse.provider.BouncyCastleJsseProvider;
```

The Bouncy Castle provider must be added as a valid provider and also must be configured to operate in FIPS mode:

```text
System.setProperty("org.bouncycastle.fips.approved_only","true");
Security.addProvider(new BouncyCastleFipsProvider());

//required to use BCJSSE when SSLProvider is set to sslpPlatform
Security.addProvider(new BouncyCastleJsseProvider("fips:BCFIPS"));

//optional - configure logging level of BCJSSE
Logger.getLogger("org.bouncycastle.jsse").setLevel(java.util.logging.Level.OFF);

//configure the class to use BCJSSE
component.setSSLProvider(1); //platform
component.config("UseFIPSCompliantAPI=true");
```

 NOTE: TLS 1.3 support requires the Bouncy Castle TLS library version 1.0.14 or later.

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 classes 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](https://www.nsoftware.com/kb/articles/fips.rst) article.

NOTE: Enabling FIPS compliance requires a special license; please contact [sales@nsoftware.com](mailto:sales@nsoftware.com) for details.

**UseInternalSecurityAPI**: Whether or not to use the system security libraries or an internal implementation. When set to *false*, the class will use the system security libraries by default to perform cryptographic functions where applicable.

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

 This setting is set to *false* by default on all platforms.

**UseVirtualThreads**: Whether threads created by the class use virtual threads instead of platform threads.If set to *true*, when the class creates a thread, it will be created as a virtual thread instead of a platform thread. Virtual threads are lightweight threads managed by the JVM that are multiplexed onto a small pool of carrier threads, significantly reducing memory usage and platform thread count under high-concurrency workloads. Requires Java 24 or later. The default value is *false*.

# Trappable Errors ([CMAC](#cmac-class) Class)

### CMAC Errors

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