# Argon2 Component

This component implements Argon2 cryptographic hashing function designed for password hashing and protecting against various types of attacks.

## Syntax

```text
nsoftware.IPWorksEncrypt.Argon2
```

## Remarks

Argon2 is a memory-hard algorithm that can be used for secure key derivation. It supports three different variants of the algorithm.

To create a key using this component, start by setting the required properties:

- [Password](#password-property-argon2-component)
- [Salt](#salt-property-argon2-component)

Optionally, specify the [Algorithm](#algorithm-property-argon2-component) variant, [KeyLength](#keylength-property-argon2-component) in bytes, number of [Iterations](#iterations-property-argon2-component), degree of [Parallelism](#parallelism-property-argon2-component) and [MemoryCost](#memorycost-property-argon2-component) in kilobytes.

After calling the [CreateKey](#createkey-method-argon2-component) method, the [Key](#key-property-argon2-component) will be populated with the derived key.

NOTE: By default, the component uses the following values which are recommended by RFC 9106: Argon2id variant with 3 iterations, 4 degrees of parallelism, 64 MB of RAM, and 32 byte key length.

**Create Key Example**

```csharp
//Create a key using Argon2 component
Argon2 argon2 = new Argon2();
argon2.Password = "password";
argon2.Salt = "AAAABBBBCCCCDDDD"; //16 bytes string
argon2.UseHex = true; //hex encoded key
argon2.CreateKey();
Console.WriteLine(argon2.Key); //outputs the derived key, 32 bytes by default
```

## Property List

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

|  |  |
| --- | --- |
| [Algorithm](#algorithm-property-argon2-component) | The variant used to derive the key. |
| [Iterations](#iterations-property-argon2-component) | Number of iterations to perform. |
| [Key](#key-property-argon2-component) | The derived key. |
| [KeyLength](#keylength-property-argon2-component) | The desired length of the derived key (in bytes). |
| [MemoryCost](#memorycost-property-argon2-component) | The memory usage in kilobytes. |
| [Parallelism](#parallelism-property-argon2-component) | The degree of parallelism. |
| [Password](#password-property-argon2-component) | The password from which a derived key is generated. |
| [Salt](#salt-property-argon2-component) | The cryptographic salt used during key creation. |
| [UseHex](#usehex-property-argon2-component) | Whether the key 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-argon2-component) | Sets or retrieves a configuration setting. |
| [CreateKey](#createkey-method-argon2-component) | Derives a key from the specified password. |
| [Reset](#reset-method-argon2-component) | Resets the component. |

## 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-argon2-component) | Fired when information is available about errors during data delivery. |

## Config Settings

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

|  |  |
| --- | --- |
| [AssociatedData](#AssociatedData) | Optional associated data. |
| [Secret](#Secret) | Optional secret. |
| [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. |

# Algorithm Property ([Argon2](#argon2-component) Component)

The variant used to derive the key.

## Syntax

```text
public Argon2Algorithms Algorithm { get; set; }
enum Argon2Algorithms {
  aArgon2d,
  aArgon2i,
  aArgon2id
}
```

## Default Value

2

## Remarks

This property specifies which type of algorithm to use. Possible values are:

|  |  |
| --- | --- |
| 0 (aArgon2d) | Argon2d maximizes resistance to GPU cracking attacks, but is more vulnerable to side-channel attacks. |
| 1 (aArgon2i) | Argon2i is optimized to resist side-channel attacks, but it is slower as it makes more passes over the memory to protect from tradeoff attacks. |
| 2 (aArgon2id - Default) | Argon2id is a hybrid of Argon2i and Argon2d which provides some of Argon2i's resistance to side-channel cache timing attacks and much of Argon2d's resistance to GPU cracking attacks. |

# Iterations Property ([Argon2](#argon2-component) Component)

Number of iterations to perform.

## Syntax

```text
public int Iterations { get; set; }
```

## Default Value

3

## Remarks

The number of iterations is used to adjust the running time independently of the memory size. Valid values are from 1 to 2^(32)-1.

# Key Property ([Argon2](#argon2-component) Component)

The derived key.

## Syntax

```text
public string Key { get; }
public byte[] KeyB { get; }
```

## Default Value

""

## Remarks

This property holds the derived key. After calling [CreateKey](#createkey-method-argon2-component) this property will be populated.

This property is read-only.

# KeyLength Property ([Argon2](#argon2-component) Component)

The desired length of the derived key (in bytes).

## Syntax

```text
public int KeyLength { get; set; }
```

## Default Value

32

## Remarks

This property specifies the length of the key (in bytes) which will be created when [CreateKey](#createkey-method-argon2-component) is called. Valid values are from 4 to 2^(32)-1.

# MemoryCost Property ([Argon2](#argon2-component) Component)

The memory usage in kilobytes.

## Syntax

```text
public int MemoryCost { get; set; }
```

## Default Value

65536

## Remarks

This property defines the memory used (in kilobytes) when calling [CreateKey](#createkey-method-argon2-component).

# Parallelism Property ([Argon2](#argon2-component) Component)

The degree of parallelism.

## Syntax

```text
public int Parallelism { get; set; }
```

## Default Value

4

## Remarks

This property specifies the number of lanes used when calling [CreateKey](#createkey-method-argon2-component).

# Password Property ([Argon2](#argon2-component) Component)

The password from which a derived key is generated.

## Syntax

```text
public string Password { get; set; }
public byte[] PasswordB { get; set; }
```

## Default Value

""

## Remarks

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

# Salt Property ([Argon2](#argon2-component) Component)

The cryptographic salt used during key creation.

## Syntax

```text
public string Salt { get; set; }
public byte[] SaltB { get; set; }
```

## Default Value

""

## Remarks

This property specifies the salt used when [CreateKey](#createkey-method-argon2-component) is called. The salt should be a unique value and should be at least 16 bytes in length.

# UseHex Property ([Argon2](#argon2-component) Component)

Whether the key is hex encoded.

## Syntax

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

## Default Value

False

## Remarks

This property specifies whether the created [Key](#key-property-argon2-component) is hex encoded when calling [CreateKey](#createkey-method-argon2-component). The default value is *false*.

# Config Method ([Argon2](#argon2-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-argon2-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-argon2-component), you must call *Config("PROPERTY")*. The value will be returned as a string.

# CreateKey Method ([Argon2](#argon2-component) Component)

Derives a key from the specified password.

## Syntax

```text
public void CreateKey();

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

## Remarks

This method derives a key from the specified password using Argon2.

The following properties are applicable when calling this method:

- [Password](#password-property-argon2-component) (required)
- [Salt](#salt-property-argon2-component) (required)
- [Algorithm](#algorithm-property-argon2-component)
- [Iterations](#iterations-property-argon2-component)
- [KeyLength](#keylength-property-argon2-component)
- [MemoryCost](#memorycost-property-argon2-component)
- [Parallelism](#parallelism-property-argon2-component)

 This method populates the [Key](#key-property-argon2-component) property with the created (derived) key.

**Create Key Example**

```csharp
//Create a key using Argon2 component
Argon2 argon2 = new Argon2();
argon2.Password = "password";
argon2.Salt = "AAAABBBBCCCCDDDD"; //16 bytes string
argon2.UseHex = true; //hex encoded key
argon2.CreateKey();
Console.WriteLine(argon2.Key); //outputs the derived key, 32 bytes by default
```

# Reset Method ([Argon2](#argon2-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.

# Error Event ([Argon2](#argon2-component) Component)

Fired when information is available about errors during data delivery.

## Syntax

```text
public event OnErrorHandler OnError;

public delegate void OnErrorHandler(object sender, Argon2ErrorEventArgs e);

public class Argon2ErrorEventArgs : 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-argon2-component) section.

# Config Settings ([Argon2](#argon2-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-argon2-component) method.

### Argon2 Config Settings

**AssociatedData**: Optional associated data.The associated data parameter, which is used to input any additional data into the hash value. The data specified must be hex encoded. If used, it must have a length not greater than 2^(32)-1 bytes.

```csharp
Argon2 argon2 = new Argon2();
argon2.Password = "password";
argon2.Salt = "AAAABBBBCCCCDDDD";
argon2.Config("AssociatedData=040404040404040404040404"); //hex encoded value
argon2.CreateKey();
```

**Secret**: Optional secret.The secret parameter, which is used for keyed hashing. This allows a secret key to be input at hashing time into the value of the hash. The data specified must be hex encoded. This means that even if the salts and hashes are compromised, an attacker cannot use brute-force to find the password without the key. If used, it must have a length not greater than 2^(32)-1 bytes.

```csharp
Argon2 argon2 = new Argon2();
argon2.Password = "password";
argon2.Salt = "AAAABBBBCCCCDDDD";
argon2.Config("Secret=012345012345ABCD"); //hex encoded value
argon2.CreateKey();
```

### 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 ([Argon2](#argon2-component) Component)

### Argon2 Errors

|  |  |
| --- | --- |
| 105 | An invalid parameter was specified. |
| 108 | An invalid key size was specified. |
| 116 | Password must be set. |
| 117 | An error occurred during hash calculation. |
| 118 | An invalid algorithm was specified. |