# DPAPI Component

The DPAPI component allows you to protect and unprotect data.

## Syntax

```text
nsoftware.IPWorksEncrypt.DPAPI
```

## Remarks

On Windows, the component supports the classic Microsoft Windows Data Protection API (DPAPI) or CNG DPAPI implementation. The use of [UseCNG](#usecng-property-dpapi-component) determines which implementation is used. Support for macOS is also available via the macOS keychain.

The classic DPAPI functionality protects data on a single system. The CNG DPAPI is designed with modern use cases involved. In many cases, especially with cloud computing, protection and unprotection may be done on different systems. With this in mind the Microsoft CNG DPAPI allows encrypting to a set of principals that can be used to unprotect the data on other systems after authenticating. On macOS, a key is saved in the Keychain which is used to protect and uprotect data.

### Protecting Data

[Protect](#protect-method-dpapi-component) protects the specified data.

On Windows, the component supports the classic Microsoft Windows Data Protection API (DPAPI) or CNG DPAPI implementation. The use of [UseCNG](#usecng-property-dpapi-component) determines which implementation is used. Support for macOS is also available via the macOS keychain.

When using classic DPAPI ([UseCNG](#usecng-property-dpapi-component) is *False*), the following optional properties are applicable:

- [DataDescription](#datadescription-property-dpapi-component)
- [Password](#password-property-dpapi-component)
- [PromptTitle](#prompttitle-property-dpapi-component)
- [PromptUser](#promptuser-property-dpapi-component)

When using CNG DPAPI ([UseCNG](#usecng-property-dpapi-component) is *True*), the following properties are applicable:

- [ProtectionDescriptor](#protectiondescriptor-property-dpapi-component) (required)
- [EscapeDescriptor](#EscapeDescriptor)
- [UseStreamMode](#UseStreamMode)

On macOS, the following settings are applicable:

- [UseSystemKeychain](#UseSystemKeychain)
- [KeychainServiceName](#KeychainServiceName)

 **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:

- [SetInputStream](#setinputstream-method-dpapi-component)
- [InputFile](#inputfile-property-dpapi-component)
- [InputMessage](#inputmessage-property-dpapi-component)

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

- [SetOutputStream](#setoutputstream-method-dpapi-component)
- [OutputFile](#outputfile-property-dpapi-component)
- [OutputMessage](#outputmessage-property-dpapi-component): 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).

**Code Example (Classic DPAPI - [UseCNG](#usecng-property-dpapi-component) is False)**

```csharp
//Protect
DPAPI dpapi = new DPAPI();
dpapi.InputMessage = "test";
dpapi.Protect();
byte[] protectedData = dpapi.OutputMessageB;

//Unprotect
dpapi = new DPAPI();
dpapi.InputMessageB = protectedData;
dpapi.Unprotect();
Console.WriteLine(dpapi.OutputMessage); //outputs "test"
```

**Code Example (CNG DPAPI - [UseCNG](#usecng-property-dpapi-component) is True**)

```csharp
//Protect
DPAPI dpapi = new DPAPI();
dpapi.UseCNG = true;
dpapi.ProtectionDescriptor = "LOCAL=user";
dpapi.InputMessage = "test";
dpapi.Protect();
byte[] protectedData = dpapi.OutputMessageB;

//Unprotect
dpapi = new DPAPI();
dpapi.UseCNG = true;
dpapi.InputMessageB = protectedData;
dpapi.Unprotect();
Console.WriteLine(dpapi.OutputMessage); //outputs "test"
```

**Code Example (macOS**)

```csharp
//Protect
DPAPI dpapi = new DPAPI();
dpapi.Config("UseSystemKeychain=false");
dpapi.Config("KeychainServiceName=nsoftware OSDP User Key");
dpapi.InputMessage = "test";
dpapi.Protect();
byte[] protectedData = dpapi.OutputMessageB;

//Unprotect
dpapi = new DPAPI();
dpapi.Config("UseSystemKeychain=false");
dpapi.Config("KeychainServiceName=nsoftware OSDP User Key");
dpapi.InputMessageB = protectedData;
dpapi.Unprotect();
Console.WriteLine(dpapi.OutputMessage); //outputs "test"
```

### Unprotecting Data

[Unprotect](#unprotect-method-dpapi-component) unprotects the specified data.

On Windows, the component supports the classic Microsoft Windows Data Protection API (DPAPI) or CNG DPAPI implementation. The use of [UseCNG](#usecng-property-dpapi-component) determines which implementation is used. Support for macOS is also available via the macOS keychain.

When using classic DPAPI ([UseCNG](#usecng-property-dpapi-component) is *False*), the following optional properties are applicable:

- [DataDescription](#datadescription-property-dpapi-component) (populated after completion)
- [Password](#password-property-dpapi-component)

When using CNG DPAPI ([UseCNG](#usecng-property-dpapi-component) is *True*), the following properties are applicable:

- [ProtectionDescriptor](#protectiondescriptor-property-dpapi-component) (populated after completion)
- [UseStreamMode](#UseStreamMode)

On macOS, the following settings are applicable:

- [UseSystemKeychain](#UseSystemKeychain)
- [KeychainServiceName](#KeychainServiceName)

**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:

- [SetInputStream](#setinputstream-method-dpapi-component)
- [InputFile](#inputfile-property-dpapi-component)
- [InputMessage](#inputmessage-property-dpapi-component)

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

- [SetOutputStream](#setoutputstream-method-dpapi-component)
- [OutputFile](#outputfile-property-dpapi-component)
- [OutputMessage](#outputmessage-property-dpapi-component): 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).

**Code Example (Classic DPAPI - [UseCNG](#usecng-property-dpapi-component) is False)**

```csharp
//Protect
DPAPI dpapi = new DPAPI();
dpapi.InputMessage = "test";
dpapi.Protect();
byte[] protectedData = dpapi.OutputMessageB;

//Unprotect
dpapi = new DPAPI();
dpapi.InputMessageB = protectedData;
dpapi.Unprotect();
Console.WriteLine(dpapi.OutputMessage); //outputs "test"
```

**Code Example (CNG DPAPI - [UseCNG](#usecng-property-dpapi-component) is True**)

```csharp
//Protect
DPAPI dpapi = new DPAPI();
dpapi.UseCNG = true;
dpapi.ProtectionDescriptor = "LOCAL=user";
dpapi.InputMessage = "test";
dpapi.Protect();
byte[] protectedData = dpapi.OutputMessageB;

//Unprotect
dpapi = new DPAPI();
dpapi.UseCNG = true;
dpapi.InputMessageB = protectedData;
dpapi.Unprotect();
Console.WriteLine(dpapi.OutputMessage); //outputs "test"
```

**Code Example (macOS**)

```csharp
//Protect
DPAPI dpapi = new DPAPI();
dpapi.Config("UseSystemKeychain=false");
dpapi.Config("KeychainServiceName=nsoftware OSDP User Key");
dpapi.InputMessage = "test";
dpapi.Protect();
byte[] protectedData = dpapi.OutputMessageB;

//Unprotect
dpapi = new DPAPI();
dpapi.Config("UseSystemKeychain=false");
dpapi.Config("KeychainServiceName=nsoftware OSDP User Key");
dpapi.InputMessageB = protectedData;
dpapi.Unprotect();
Console.WriteLine(dpapi.OutputMessage); //outputs "test"
```

## Property List

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

|  |  |
| --- | --- |
| [DataDescription](#datadescription-property-dpapi-component) | The description of data. |
| [InputFile](#inputfile-property-dpapi-component) | The file to process. |
| [InputMessage](#inputmessage-property-dpapi-component) | The message to process. |
| [OutputFile](#outputfile-property-dpapi-component) | The output file when encrypting or decrypting. |
| [OutputMessage](#outputmessage-property-dpapi-component) | The output message after processing. |
| [Overwrite](#overwrite-property-dpapi-component) | Indicates whether or not the component should overwrite files. |
| [Password](#password-property-dpapi-component) | An optional password to further protect data. |
| [PromptTitle](#prompttitle-property-dpapi-component) | The title of the prompt window. |
| [PromptUser](#promptuser-property-dpapi-component) | Whether to display a prompt. |
| [ProtectionDescriptor](#protectiondescriptor-property-dpapi-component) | The CNG protection descriptor. |
| [UseCNG](#usecng-property-dpapi-component) | Whether to use CNG DPAPI. |
| [UseHex](#usehex-property-dpapi-component) | Whether input or output is hex encoded. |

## Method List

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

|  |  |
| --- | --- |
| [Config](#config-method-dpapi-component) | Sets or retrieves a configuration setting. |
| [Protect](#protect-method-dpapi-component) | Protects the data. |
| [Reset](#reset-method-dpapi-component) | Resets the component. |
| [SetInputStream](#setinputstream-method-dpapi-component) | Sets the stream from which the component will read data to encrypt or decrypt. |
| [SetOutputStream](#setoutputstream-method-dpapi-component) | Sets the stream to which the component will write encrypted or decrypted data. |
| [Unprotect](#unprotect-method-dpapi-component) | Unprotects the 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.*

|  |  |
| --- | --- |
| [Error](#error-event-dpapi-component) | Fired when information is available about errors during data delivery. |
| [Progress](#progress-event-dpapi-component) | Fired 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.*

|  |  |
| --- | --- |
| [CloseInputStreamAfterProcessing](#CloseInputStreamAfterProcessing) | Determines whether or not the input stream is closed after processing. |
| [CloseOutputStreamAfterProcessing](#CloseOutputStreamAfterProcessing) | Determines whether or not the output stream is closed after processing. |
| [EscapeDescriptor](#EscapeDescriptor) | Whether to escape the protection descriptor. |
| [KeychainServiceName](#KeychainServiceName) | Service name for the keychain on macOS. |
| [ProtectionFlags](#ProtectionFlags) | Used to specify additional options. |
| [UseStreamMode](#UseStreamMode) | Whether to use the CNG streaming operations. |
| [UseSystemKeychain](#UseSystemKeychain) | Whether to save the key and IV in the macOS System keychain. |
| [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. |
| [UseFIPSCompliantAPI](#UseFIPSCompliantAPI) | Tells the component whether or not to use FIPS certified APIs. |
| [UseInternalSecurityAPI](#UseInternalSecurityAPI) | Whether or not to use the system security libraries or an internal implementation. |

# DataDescription Property ([DPAPI](#dpapi-component) Component)

The description of data.

## Syntax

```text
public string DataDescription { get; set; }
```

## Default Value

""

## Remarks

This property specifies an optional description of the protected data.

This may be set before calling [Protect](#protect-method-dpapi-component). This property will be populated when calling [Unprotect](#unprotect-method-dpapi-component).

This setting is not applicable when [UseCNG](#usecng-property-dpapi-component) is set to *True*.

This setting is not applicable on macOS.

# InputFile Property ([DPAPI](#dpapi-component) Component)

The file to process.

## Syntax

```text
public string InputFile { get; set; }
```

## 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:

- [SetInputStream](#setinputstream-method-dpapi-component)
- InputFile
- [InputMessage](#inputmessage-property-dpapi-component)

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

- [SetOutputStream](#setoutputstream-method-dpapi-component)
- [OutputFile](#outputfile-property-dpapi-component)
- [OutputMessage](#outputmessage-property-dpapi-component): 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 ([DPAPI](#dpapi-component) Component)

The message to process.

## Syntax

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

## 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:

- [SetInputStream](#setinputstream-method-dpapi-component)
- [InputFile](#inputfile-property-dpapi-component)
- InputMessage

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

- [SetOutputStream](#setoutputstream-method-dpapi-component)
- [OutputFile](#outputfile-property-dpapi-component)
- [OutputMessage](#outputmessage-property-dpapi-component): 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).

# OutputFile Property ([DPAPI](#dpapi-component) Component)

The output file when encrypting or decrypting.

## Syntax

```text
public string OutputFile { get; set; }
```

## Default Value

""

## Remarks

This property specifies the file to which the output will be written when Encrypt or Decrypt is called. This may be set to an absolute or relative path.

This property is only applicable to Encrypt and Decrypt.

**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:

- [SetInputStream](#setinputstream-method-dpapi-component)
- [InputFile](#inputfile-property-dpapi-component)
- [InputMessage](#inputmessage-property-dpapi-component)

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

- [SetOutputStream](#setoutputstream-method-dpapi-component)
- OutputFile
- [OutputMessage](#outputmessage-property-dpapi-component): 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).

# OutputMessage Property ([DPAPI](#dpapi-component) Component)

The output message after processing.

## Syntax

```text
public string OutputMessage { get; }
public byte[] OutputMessageB { get; }
```

## Default Value

""

## Remarks

This property will be populated with the output from the operation if [OutputFile](#outputfile-property-dpapi-component) and [SetOutputStream](#setoutputstream-method-dpapi-component) are not set.

**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:

- [SetInputStream](#setinputstream-method-dpapi-component)
- [InputFile](#inputfile-property-dpapi-component)
- [InputMessage](#inputmessage-property-dpapi-component)

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

- [SetOutputStream](#setoutputstream-method-dpapi-component)
- [OutputFile](#outputfile-property-dpapi-component)
- 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).

This property is read-only and not available at design time.

# Overwrite Property ([DPAPI](#dpapi-component) Component)

Indicates whether or not the component should overwrite files.

## Syntax

```text
public bool Overwrite { get; set; }
```

## Default Value

False

## Remarks

This property indicates whether or not the component will overwrite [OutputFile](#outputfile-property-dpapi-component). If Overwrite is False, an error will be thrown whenever [OutputFile](#outputfile-property-dpapi-component) exists before an operation. The default value is False.

# Password Property ([DPAPI](#dpapi-component) Component)

An optional password to further protect data.

## Syntax

```text
public string Password { get; set; }
```

## Default Value

""

## Remarks

This property may be set to a password to protect the data further.

When protecting data without specifying a password any application running under the same user account can unprotect the data. By specifying a password another piece of information is required to unprotect the data.

This may be set before calling [Protect](#protect-method-dpapi-component). If a password was specified when protecting data it must be set before calling [Unprotect](#unprotect-method-dpapi-component).

This setting is not applicable when [UseCNG](#usecng-property-dpapi-component) is set to *True*.

This setting is not applicable on macOS.

# PromptTitle Property ([DPAPI](#dpapi-component) Component)

The title of the prompt window.

## Syntax

```text
public string PromptTitle { get; set; }
```

## Default Value

""

## Remarks

This property specifies the title of the prompt dialog if [PromptUser](#promptuser-property-dpapi-component) is True. The default value is empty string.

This setting is not applicable when [UseCNG](#usecng-property-dpapi-component) is set to *True*.

This setting is not applicable on macOS.

# PromptUser Property ([DPAPI](#dpapi-component) Component)

Whether to display a prompt.

## Syntax

```text
public bool PromptUser { get; set; }
```

## Default Value

False

## Remarks

This property specifies whether a prompt is displayed when calling [Protect](#protect-method-dpapi-component). This dialog is created by the system and informs the user of the request action. The user may accept or cancel the request. If the user cancels the request the [Protect](#protect-method-dpapi-component) method throws an exception.

When True the [PromptTitle](#prompttitle-property-dpapi-component) may be set to customize the window title.

This setting is not applicable when [UseCNG](#usecng-property-dpapi-component) is set to *True*.

This setting is not applicable on macOS. ;

# ProtectionDescriptor Property ([DPAPI](#dpapi-component) Component)

The CNG protection descriptor.

## Syntax

```text
public string ProtectionDescriptor { get; set; }
```

## Default Value

""

## Remarks

This property specifies the protection descriptor rule string. The protection descriptor is used by the system to decide which entities can unprotect the data at a later time. This property must be specified before calling [Protect](#protect-method-dpapi-component). This property is populated after calling [Unprotect](#unprotect-method-dpapi-component).

Protection descriptors can be defined for the following types of authorization:

- A local user or machine
- An account or group in an Active Directory forest
- A set of web credentials
- A certificate in the user's certificate store

A local user or machine may be used for machines that are or are not on a domain. For instance:

- *LOCAL=user*
- *LOCAL=machine*

The use of *SID* and *SDDL* requires that the machine be part of a domain. For instance:

- *SID=S-1-5-21-4392301 AND SID=S-1-5-21-3101812*
- *SDDL=O:S-1-5-5-0-290724G:SYD:(A;;CCDC;;;S-1-5-5-0-290724)(A;;DC;;;WD)*

Certificates may also be used as a descriptor. To decrypt, the certificate with corresponding private key must be present in the user's certificate store. The public certificate can be specified as the SHA1 thumbprint (hash) of the certificate, or the base64 encoded certificate itself. For instance:

- *CERTIFICATE=HashID:28ac375635b82ca3e20a1c9422145bc93965dae7*
- *CERTIFICATE=CertBlob:MIIC7TCCAdWgAw...pgpVgYpppr*

 Note: The base64 certificate data should not include any headers, footers, or whitespace.

The use of *AND* and *OR* operators are accepted in order to encrypt data for multiple parties or establish multiple conditions for decryption.

For more details about protection descriptors and accepted formats please refer to the [Microsoft Documentation for Protection Descriptors](https://docs.microsoft.com/en-us/windows/desktop/seccng/protection-descriptors)

This setting is only applicable when [UseCNG](#usecng-property-dpapi-component) is set to *True*.

This setting is not applicable on macOS.

# UseCNG Property ([DPAPI](#dpapi-component) Component)

Whether to use CNG DPAPI.

## Syntax

```text
public bool UseCNG { get; set; }
```

## Default Value

False

## Remarks

The component supports protecting data using either the classic DPAPI or CNG DPAPI implementation. When set to *True* the CNG DPAPI implementation is used. When set to *False* (default) the classic DPAPI implementation is used.

This setting is not applicable on macOS.

# UseHex Property ([DPAPI](#dpapi-component) Component)

Whether input or output is hex encoded.

## Syntax

```text
public bool UseHex { get; set; }
```

## Default Value

False

## Remarks

This property specifies whether the encrypted data is hex encoded.

If set to True, when [Protect](#protect-method-dpapi-component) is called the component will perform the encryption as normal and then hex encode the output. [OutputMessage](#outputmessage-property-dpapi-component) or [OutputFile](#outputfile-property-dpapi-component) will hold hex encoded data.

If set to True, when [Unprotect](#unprotect-method-dpapi-component) is called the component will expect [InputMessage](#inputmessage-property-dpapi-component) or [InputFile](#inputfile-property-dpapi-component) to hold hex encoded data. The component will then hex decode the data and perform decryption as normal.

# Config Method ([DPAPI](#dpapi-component) Component)

Sets or retrieves a configuration setting.

## Syntax

```text
public string Config(string configurationString);

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

## Remarks

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

# Protect Method ([DPAPI](#dpapi-component) Component)

Protects the data.

## Syntax

```text
public void Protect();

Async Version
public async Task Protect();
public async Task Protect(CancellationToken cancellationToken);
```

## Remarks

Protect protects the specified data.

On Windows, the component supports the classic Microsoft Windows Data Protection API (DPAPI) or CNG DPAPI implementation. The use of [UseCNG](#usecng-property-dpapi-component) determines which implementation is used. Support for macOS is also available via the macOS keychain.

When using classic DPAPI ([UseCNG](#usecng-property-dpapi-component) is *False*), the following optional properties are applicable:

- [DataDescription](#datadescription-property-dpapi-component)
- [Password](#password-property-dpapi-component)
- [PromptTitle](#prompttitle-property-dpapi-component)
- [PromptUser](#promptuser-property-dpapi-component)

When using CNG DPAPI ([UseCNG](#usecng-property-dpapi-component) is *True*), the following properties are applicable:

- [ProtectionDescriptor](#protectiondescriptor-property-dpapi-component) (required)
- [EscapeDescriptor](#EscapeDescriptor)
- [UseStreamMode](#UseStreamMode)

On macOS, the following settings are applicable:

- [UseSystemKeychain](#UseSystemKeychain)
- [KeychainServiceName](#KeychainServiceName)

 **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:

- [SetInputStream](#setinputstream-method-dpapi-component)
- [InputFile](#inputfile-property-dpapi-component)
- [InputMessage](#inputmessage-property-dpapi-component)

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

- [SetOutputStream](#setoutputstream-method-dpapi-component)
- [OutputFile](#outputfile-property-dpapi-component)
- [OutputMessage](#outputmessage-property-dpapi-component): 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).

**Code Example (Classic DPAPI - [UseCNG](#usecng-property-dpapi-component) is False)**

```csharp
//Protect
DPAPI dpapi = new DPAPI();
dpapi.InputMessage = "test";
dpapi.Protect();
byte[] protectedData = dpapi.OutputMessageB;

//Unprotect
dpapi = new DPAPI();
dpapi.InputMessageB = protectedData;
dpapi.Unprotect();
Console.WriteLine(dpapi.OutputMessage); //outputs "test"
```

**Code Example (CNG DPAPI - [UseCNG](#usecng-property-dpapi-component) is True**)

```csharp
//Protect
DPAPI dpapi = new DPAPI();
dpapi.UseCNG = true;
dpapi.ProtectionDescriptor = "LOCAL=user";
dpapi.InputMessage = "test";
dpapi.Protect();
byte[] protectedData = dpapi.OutputMessageB;

//Unprotect
dpapi = new DPAPI();
dpapi.UseCNG = true;
dpapi.InputMessageB = protectedData;
dpapi.Unprotect();
Console.WriteLine(dpapi.OutputMessage); //outputs "test"
```

**Code Example (macOS**)

```csharp
//Protect
DPAPI dpapi = new DPAPI();
dpapi.Config("UseSystemKeychain=false");
dpapi.Config("KeychainServiceName=nsoftware OSDP User Key");
dpapi.InputMessage = "test";
dpapi.Protect();
byte[] protectedData = dpapi.OutputMessageB;

//Unprotect
dpapi = new DPAPI();
dpapi.Config("UseSystemKeychain=false");
dpapi.Config("KeychainServiceName=nsoftware OSDP User Key");
dpapi.InputMessageB = protectedData;
dpapi.Unprotect();
Console.WriteLine(dpapi.OutputMessage); //outputs "test"
```

# Reset Method ([DPAPI](#dpapi-component) Component)

Resets the component.

## Syntax

```text
public void Reset();

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

## Remarks

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

# SetInputStream Method ([DPAPI](#dpapi-component) Component)

Sets the stream from which the component will read data to encrypt or decrypt.

## Syntax

```text
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);
```

## Remarks

This method sets the stream from which the component will read data to encrypt or decrypt.

**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:

- SetInputStream
- [InputFile](#inputfile-property-dpapi-component)
- [InputMessage](#inputmessage-property-dpapi-component)

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

- [SetOutputStream](#setoutputstream-method-dpapi-component)
- [OutputFile](#outputfile-property-dpapi-component)
- [OutputMessage](#outputmessage-property-dpapi-component): 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).

# SetOutputStream Method ([DPAPI](#dpapi-component) Component)

Sets the stream to which the component will write encrypted or decrypted data.

## Syntax

```text
public void SetOutputStream(System.IO.Stream outputStream);

Async Version
public async Task SetOutputStream(System.IO.Stream outputStream);
public async Task SetOutputStream(System.IO.Stream outputStream, CancellationToken cancellationToken);
```

## Remarks

This method sets the stream to which the component will write encrypted or decrypted data.

**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:

- [SetInputStream](#setinputstream-method-dpapi-component)
- [InputFile](#inputfile-property-dpapi-component)
- [InputMessage](#inputmessage-property-dpapi-component)

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

- SetOutputStream
- [OutputFile](#outputfile-property-dpapi-component)
- [OutputMessage](#outputmessage-property-dpapi-component): 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).

# Unprotect Method ([DPAPI](#dpapi-component) Component)

Unprotects the data.

## Syntax

```text
public void Unprotect();

Async Version
public async Task Unprotect();
public async Task Unprotect(CancellationToken cancellationToken);
```

## Remarks

Unprotect unprotects the specified data.

On Windows, the component supports the classic Microsoft Windows Data Protection API (DPAPI) or CNG DPAPI implementation. The use of [UseCNG](#usecng-property-dpapi-component) determines which implementation is used. Support for macOS is also available via the macOS keychain.

When using classic DPAPI ([UseCNG](#usecng-property-dpapi-component) is *False*), the following optional properties are applicable:

- [DataDescription](#datadescription-property-dpapi-component) (populated after completion)
- [Password](#password-property-dpapi-component)

When using CNG DPAPI ([UseCNG](#usecng-property-dpapi-component) is *True*), the following properties are applicable:

- [ProtectionDescriptor](#protectiondescriptor-property-dpapi-component) (populated after completion)
- [UseStreamMode](#UseStreamMode)

On macOS, the following settings are applicable:

- [UseSystemKeychain](#UseSystemKeychain)
- [KeychainServiceName](#KeychainServiceName)

**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:

- [SetInputStream](#setinputstream-method-dpapi-component)
- [InputFile](#inputfile-property-dpapi-component)
- [InputMessage](#inputmessage-property-dpapi-component)

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

- [SetOutputStream](#setoutputstream-method-dpapi-component)
- [OutputFile](#outputfile-property-dpapi-component)
- [OutputMessage](#outputmessage-property-dpapi-component): 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).

**Code Example (Classic DPAPI - [UseCNG](#usecng-property-dpapi-component) is False)**

```csharp
//Protect
DPAPI dpapi = new DPAPI();
dpapi.InputMessage = "test";
dpapi.Protect();
byte[] protectedData = dpapi.OutputMessageB;

//Unprotect
dpapi = new DPAPI();
dpapi.InputMessageB = protectedData;
dpapi.Unprotect();
Console.WriteLine(dpapi.OutputMessage); //outputs "test"
```

**Code Example (CNG DPAPI - [UseCNG](#usecng-property-dpapi-component) is True**)

```csharp
//Protect
DPAPI dpapi = new DPAPI();
dpapi.UseCNG = true;
dpapi.ProtectionDescriptor = "LOCAL=user";
dpapi.InputMessage = "test";
dpapi.Protect();
byte[] protectedData = dpapi.OutputMessageB;

//Unprotect
dpapi = new DPAPI();
dpapi.UseCNG = true;
dpapi.InputMessageB = protectedData;
dpapi.Unprotect();
Console.WriteLine(dpapi.OutputMessage); //outputs "test"
```

**Code Example (macOS**)

```csharp
//Protect
DPAPI dpapi = new DPAPI();
dpapi.Config("UseSystemKeychain=false");
dpapi.Config("KeychainServiceName=nsoftware OSDP User Key");
dpapi.InputMessage = "test";
dpapi.Protect();
byte[] protectedData = dpapi.OutputMessageB;

//Unprotect
dpapi = new DPAPI();
dpapi.Config("UseSystemKeychain=false");
dpapi.Config("KeychainServiceName=nsoftware OSDP User Key");
dpapi.InputMessageB = protectedData;
dpapi.Unprotect();
Console.WriteLine(dpapi.OutputMessage); //outputs "test"
```

# Error Event ([DPAPI](#dpapi-component) Component)

Fired when information is available about errors during data delivery.

## Syntax

```text
public event OnErrorHandler OnError;

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

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

## 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](#trappable-errors-dpapi-component) section.

# Progress Event ([DPAPI](#dpapi-component) Component)

Fired as progress is made.

## Syntax

```text
public event OnProgressHandler OnProgress;

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

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

## 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 ([DPAPI](#dpapi-component) 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](#config-method-dpapi-component) method.

### DPAPI 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-dpapi-component) is closed after processing is complete. The default value is True.

**CloseOutputStreamAfterProcessing**: Determines whether or not the output stream is closed after processing.Determines whether or not the output stream set by [SetOutputStream](#setoutputstream-method-dpapi-component) is closed after processing is complete. The default value is True.

**EscapeDescriptor**: Whether to escape the protection descriptor.This setting controls whether the [ProtectionDescriptor](#protectiondescriptor-property-dpapi-component) value is escaped when [Protect](#protect-method-dpapi-component) is called. When set to *False* (default) the value is passed exactly as provided to the underlying system libraries. When set to *True* the value is first escaped according to the escaping rules defined by Microsoft.

The default value of [EscapeDescriptor](#EscapeDescriptor) is *True*.

This setting is only applicable when [UseCNG](#usecng-property-dpapi-component) is set to *True*.

This setting is not applicable on macOS.

**KeychainServiceName**: Service name for the keychain on macOS.This setting is used to specify the service name for the keychain on macOS. By default, *nsoftware OSDP User Key* is used as the service name for the user keychain. *nsoftware OSDP System Key* is used for the system keychain when [UseSystemKeychain](#UseSystemKeychain) is set to *True*.

**ProtectionFlags**: Used to specify additional options.Additional options are available to restrict or change the behavior of the protect and unprotect operations.

By default no additional settings are specified (the value is 0). You may set this property to the binary 'OR' of one or more of the following values:

|  |  |  |
| --- | --- | --- |
| 1 (0x1) | CRYPTPROTECT_UI_FORBIDDEN | This flag is used for remote situations where presenting a user interface (UI) is not an option. When this flag is set and a UI is specified for either the protect or unprotect operation, the operation fails. |
| 4 (0x4) | CRYPTPROTECT_LOCAL_MACHINE | When this flag is set, it associates the data encrypted with the current computer instead of with an individual user. This is only applicable when calling [Protect](#protect-method-dpapi-component). |
| 8 (0x8) | CRYPTPROTECT_CRED_SYNC | When this flag is used, no data is actually protected. Instead all MasterKeys are queried from disk, which will cause re-encryption in memory, presumably under a changed password. This is only applicable when calling [Protect](#protect-method-dpapi-component). |
| 16 (0x10) | CRYPTPROTECT_AUDIT | This flag causes DPAPI to generate an audit when this data is protected or unprotected. This is only applicable when calling [Protect](#protect-method-dpapi-component). |
| 64 (0x40) | CRYPTPROTECT_VERIFY_PROTECTION | If the protected data blob would be better protected under a new call to the internal protect function and this call succeeds, then GetLastError will return a CRYPT_I_NEW_PROTECTION_REQUIRED status code. This is only applicable when calling [Unprotect](#unprotect-method-dpapi-component). |
| 536870912 (0x20000000) | CRYPTPROTECT_SYSTEM | If data was protected with this flag set, then this flag must be set to unprotect the data. |

This setting is not applicable when [UseCNG](#usecng-property-dpapi-component) is set to *True*.

This setting is not applicable on macOS.

**UseStreamMode**: Whether to use the CNG streaming operations.When set to *True* the component will use the CNG streaming operations when [Protect](#protect-method-dpapi-component) and [Unprotect](#unprotect-method-dpapi-component) are called. When working with large amounts of data this can reduce the memory overhead during processing. Note that when enabled [InputFile](#inputfile-property-dpapi-component) and [OutputFile](#outputfile-property-dpapi-component) or [SetInputStream](#setinputstream-method-dpapi-component) and [SetOutputStream](#setoutputstream-method-dpapi-component) should be used for optimal memory usage.

The default value of [UseStreamMode](#UseStreamMode) is *False*.

This setting is only applicable when [UseCNG](#usecng-property-dpapi-component) is set to *True*.

This setting is not applicable on macOS.

**UseSystemKeychain**: Whether to save the key and IV in the macOS System keychain.When set to *True*, the key and IV will be saved in the macOS system keychain with the service name *nsoftware OSDP System Key*. Administrator privileges are required to use this config. This config is not supported on iOS.

The default value of [UseSystemKeychain](#UseSystemKeychain) is *False*, and the key and IV are stored in the user keychain with the service name *nsoftware OSDP User Key*.

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

NOTE: This setting is applicable only on Windows.

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 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 ([DPAPI](#dpapi-component) Component)

### DPAPI Errors

|  |  |
| --- | --- |
| 104 | Cannot read or write file. |
| 109 | Cannot protect data. |
| 110 | Cannot unprotect data |
| 111 | OutputFile already exists and Overwrite is False. |
| 304 | Cannot write file. |
| 305 | Cannot read file. |
| 306 | Cannot create file. |