# Salsa20 Component

The Salsa20 class can be used to encrypt and decrypt data with the XSalsa20 and Salsa20 algorithm.

## Syntax

```text
ipworksencrypt.Salsa20
```

## Remarks

The struct implements XSalsa20 as well as Salsa20. The [Algorithm](#algorithm-property-salsa20-component) property specifies which algorithm to use when encrypting and decryption. In addition the 12 and 8 round variants of Salsa20 are supported.

Data may be encrypted and decrypted in its entirety by calling [Encrypt](#encrypt-method-salsa20-component) and [Decrypt](#decrypt-method-salsa20-component) or chunk by chunk by calling [EncryptBlock](#encryptblock-method-salsa20-component) and [DecryptBlock](#decryptblock-method-salsa20-component).

In all operations a [Key](#key-property-salsa20-component) and [IV](#iv-property-salsa20-component) must be used. If [IV](#iv-property-salsa20-component) is not set one is automatically generated. [KeyPassword](#keypassword-property-salsa20-component) may be set in order to automatically generate both a [Key](#key-property-salsa20-component) and [IV](#iv-property-salsa20-component) when a method is called. The same [KeyPassword](#keypassword-property-salsa20-component), or [Key](#key-property-salsa20-component) and [IV](#iv-property-salsa20-component) pair are used on both sides of the operation data can be encrypted and decrypted.

## Encrypt Notes

[Encrypt](#encrypt-method-salsa20-component) will encrypt the specified data. The following properties are applicable:

- [IV](#iv-property-salsa20-component) (required)
- [Key](#key-property-salsa20-component) (required)

**Input and Output Properties**

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

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

- [InputFile](#inputfile-property-salsa20-component)
- [InputMessage](#inputmessage-property-salsa20-component)

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

- [OutputFile](#outputfile-property-salsa20-component)
- [OutputMessage](#outputmessage-property-salsa20-component): The output data is written to this property if no other destination is specified.

**Additional Notes**

The [Key](#key-property-salsa20-component) property must be set to a 256 bit (32 byte) value. This is the only allowed value for ChaCha20. If [KeyPassword](#keypassword-property-salsa20-component) is set both [Key](#key-property-salsa20-component) and [IV](#iv-property-salsa20-component) will be automatically generated when [Encrypt](#encrypt-method-salsa20-component) is called.

The [IV](#iv-property-salsa20-component) must be set to a 192 bit (24 byte) value when [Algorithm](#algorithm-property-salsa20-component) is set to XSalsa. The [IV](#iv-property-salsa20-component) must be set to a 64 bit (8 byte) value when [Algorithm](#algorithm-property-salsa20-component) is set to Salsa.

If [IV](#iv-property-salsa20-component) is not set a value will automatically be generated by the struct when [Encrypt](#encrypt-method-salsa20-component) is called.

During encryption the [Progress](#progress-event-salsa20-component) event will fire as data is encrypted.

**Encrypt Example**

```csharp
Salsa20 salsa = new Salsa20();

//32 Bytes
salsa.KeyB = new byte[] { 0xBB, 0x76, 0x17, 0xC9, 0x05, 0x73, 0x4A, 0x8D, 0x59, 0x9D, 0x7B, 0x0D, 0x86, 0x2A, 0x03, 0x82, 0x50, 0x6A, 0x70, 0xFB, 0xA8, 0x56, 0x47, 0x1B, 0x1E, 0x68, 0x0B, 0x2B, 0x34, 0x18, 0x0F, 0xE2 };

//24 Bytes
salsa.IVB = new byte[] { 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7, 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7 };

salsa.InputMessage = "hello salsa!";
salsa.Encrypt();

//salsa.OutputMessageB contains the byte[] of the encrypted data. The above code produces the following encrypted bytes.
// { 0x06, 0xF4, 0xD9, 0xB4, 0x67, 0x31, 0x1C, 0x1E, 0x8E, 0xD6, 0xB5, 0x6B }
```

## Encrypt Block Notes

[EncryptBlock](#encryptblock-method-salsa20-component) will encrypt the input data and return the encrypted block. The encrypted block will always be the same length as the decrypted data. The following properties are applicable:

- [IV](#iv-property-salsa20-component) (required)
- [Key](#key-property-salsa20-component) (required)

*InputBuffer* specifies the input data to encrypt.

**EncryptBlock Example**

```csharp
Salsa20 salsa = new Salsa20();

//32 Bytes
salsa.KeyB = new byte[] { 0xBB, 0x76, 0x17, 0xC9, 0x05, 0x73, 0x4A, 0x8D, 0x59, 0x9D, 0x7B, 0x0D, 0x86, 0x2A, 0x03, 0x82, 0x50, 0x6A, 0x70, 0xFB, 0xA8, 0x56, 0x47, 0x1B, 0x1E, 0x68, 0x0B, 0x2B, 0x34, 0x18, 0x0F, 0xE2 };

//24 Bytes
salsa.IVB = new byte[] { 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7, 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7 };

byte[] tempEncryptedBlock;

//Encrypt any number of blocks of any size
tempEncryptedBlock = salsa.EncryptBlock(part1);
tempEncryptedBlock = salsa.EncryptBlock(part2);
```

## Decrypt Notes

[Decrypt](#decrypt-method-salsa20-component) will decrypt the specified data. The following properties are applicable:

- [IV](#iv-property-salsa20-component) (required)
- [Key](#key-property-salsa20-component) (required)

**Input and Output Properties**

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

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

- [InputFile](#inputfile-property-salsa20-component)
- [InputMessage](#inputmessage-property-salsa20-component)

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

- [OutputFile](#outputfile-property-salsa20-component)
- [OutputMessage](#outputmessage-property-salsa20-component): The output data is written to this property if no other destination is specified.

**Additional Notes**

The [Key](#key-property-salsa20-component) property must be set to the 256 bit (32 byte) value originally used to encrypt the data. [IV](#iv-property-salsa20-component) must be set to the original IV value used to encrypt the data.

If using a password, [KeyPassword](#keypassword-property-salsa20-component) must be set to the same [KeyPassword](#keypassword-property-salsa20-component) used when encrypting the data. This will automatically generate both [Key](#key-property-salsa20-component) and [IV](#iv-property-salsa20-component) when [Decrypt](#decrypt-method-salsa20-component) is called.

During decryption the [Progress](#progress-event-salsa20-component) event will fire as data is decrypted.

**Decrypt Example**

```csharp
Salsa20 salsa = new Salsa20();

//32 Bytes
salsa.KeyB = new byte[] { 0xBB, 0x76, 0x17, 0xC9, 0x05, 0x73, 0x4A, 0x8D, 0x59, 0x9D, 0x7B, 0x0D, 0x86, 0x2A, 0x03, 0x82, 0x50, 0x6A, 0x70, 0xFB, 0xA8, 0x56, 0x47, 0x1B, 0x1E, 0x68, 0x0B, 0x2B, 0x34, 0x18, 0x0F, 0xE2 };

//24 Bytes
salsa.IVB = new byte[] { 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7, 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7 };

salsa.InputMessageB = new byte[] { 0x06, 0xF4, 0xD9, 0xB4, 0x67, 0x31, 0x1C, 0x1E, 0x8E, 0xD6, 0xB5, 0x6B };
salsa.Decrypt();

Console.WriteLine(salsa.OutputMessage); //outputs "hello salsa!"
```

## Decrypt Block Notes

[DecryptBlock](#decryptblock-method-salsa20-component) will decrypt the input data and return the decrypted block. The decrypted block will always be the same length as the encrypted data. The following properties are applicable:

- [IV](#iv-property-salsa20-component) (required)
- [Key](#key-property-salsa20-component) (required)

*InputBuffer* specifies the input data to decrypt.

**DecryptBlock Example**

```csharp
Salsa20 salsa = new Salsa20();

//32 Bytes
salsa.KeyB = new byte[] { 0xBB, 0x76, 0x17, 0xC9, 0x05, 0x73, 0x4A, 0x8D, 0x59, 0x9D, 0x7B, 0x0D, 0x86, 0x2A, 0x03, 0x82, 0x50, 0x6A, 0x70, 0xFB, 0xA8, 0x56, 0x47, 0x1B, 0x1E, 0x68, 0x0B, 0x2B, 0x34, 0x18, 0x0F, 0xE2 };

//24 Bytes
salsa.IVB = new byte[] { 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7, 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7 };

byte[] tempDecryptedBlock;

//Decrypt any number of blocks of any size
tempDecryptedBlock = salsa.DecryptBlock(part1);
tempDecryptedBlock = salsa.DecryptBlock(part2);
```

## 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-salsa20-component) | The Salsa20 algorithm. |
| [InputFile](#inputfile-property-salsa20-component) | The file to process. |
| [InputMessage](#inputmessage-property-salsa20-component) | The message to process. |
| [IV](#iv-property-salsa20-component) | The initialization vector (IV). |
| [Key](#key-property-salsa20-component) | The secret key for the symmetric algorithm. |
| [KeyPassword](#keypassword-property-salsa20-component) | A password to generate the Key and IV . |
| [OutputFile](#outputfile-property-salsa20-component) | The output file when encrypting or decrypting. |
| [OutputMessage](#outputmessage-property-salsa20-component) | The output message after processing. |
| [Overwrite](#overwrite-property-salsa20-component) | Indicates whether or not the class should overwrite files. |
| [UseHex](#usehex-property-salsa20-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-salsa20-component) | Sets or retrieves a configuration setting. |
| [Decrypt](#decrypt-method-salsa20-component) | Decrypts the data. |
| [DecryptBlock](#decryptblock-method-salsa20-component) | Decrypts a block and returns the decrypted data. |
| [Encrypt](#encrypt-method-salsa20-component) | Encrypts the data. |
| [EncryptBlock](#encryptblock-method-salsa20-component) | Encrypts data and returns the encrypted block. |
| [Reset](#reset-method-salsa20-component) | Resets the class. |

## 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-salsa20-component) | Fired when information is available about errors during data delivery. |
| [Progress](#progress-event-salsa20-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.*

|  |  |
| --- | --- |
| [EncryptedDataEncoding](#EncryptedDataEncoding) | The encoding of the encrypted input or output data. |
| [IncludeIV](#IncludeIV) | Whether to prepend the IV to the output data and read the IV from the input data. |
| [KeyPasswordAlgorithm](#KeyPasswordAlgorithm) | The hash algorithm used to derive the Key and IV from the KeyPassword property. |
| [KeyPasswordIterations](#KeyPasswordIterations) | The number of iterations performed when using KeyPassword to derive the Key and IV. |
| [KeyPasswordSalt](#KeyPasswordSalt) | The salt value used in conjunction with the KeyPassword to derive the Key and IV. |
| [SalsaRounds](#SalsaRounds) | The number of rounds to perform. |
| [BuildInfo](#BuildInfo) | Information about the product's build. |
| [CodePage](#CodePage) | The system code page used for Unicode to Multibyte translations. |
| [LicenseInfo](#LicenseInfo) | Information about the current license. |
| [MaskSensitiveData](#MaskSensitiveData) | Whether sensitive data is masked in log messages. |
| [UseInternalSecurityAPI](#UseInternalSecurityAPI) | Whether or not to use the system security libraries or an internal implementation. |

# Algorithm Property ([Salsa20](#salsa20-component) Component)

The Salsa20 algorithm.

## Syntax

*Go Syntax*

```text
func (obj *Salsa20) Algorithm() (int32, error)func (obj *Salsa20) SetAlgorithm(value int32) error
```

## Possible Values

```text
0   // SALSA201   // XSALSA20
```

## Default Value

1

## Remarks

This property specifies the Salsa implementation to use. Possible values are:

- 0 (Salsa20)
- 1 (XSalsa20 - default)

The XSalsa20 algorithm is recommended and generally to be considered more secure. The Salsa20 algorithm is fully supported for implementations that require this. In addition the reduced 12 and 8 round variants of Salsa20 are also supported, please see [SalsaRounds](#SalsaRounds) for details.

## Data Type

**int32**

# InputFile Property ([Salsa20](#salsa20-component) Component)

The file to process.

## Syntax

*Go Syntax*

```text
func (obj *Salsa20) InputFile() (string, error)func (obj *Salsa20) SetInputFile(value string) error
```

## Default Value

""

## Remarks

This property specifies the file to be processed. Set this property to the full or relative path to the file which will be processed.

**Input and Output Properties**

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

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

- InputFile
- [InputMessage](#inputmessage-property-salsa20-component)

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

- [OutputFile](#outputfile-property-salsa20-component)
- [OutputMessage](#outputmessage-property-salsa20-component): The output data is written to this property if no other destination is specified.

## Data Type

**string**

# InputMessage Property ([Salsa20](#salsa20-component) Component)

The message to process.

## Syntax

*Go Syntax*

```text
func (obj *Salsa20) InputMessage() ([]byte, error)func (obj *Salsa20) SetInputMessage(value []byte) error
```

## Default Value

""

## Remarks

This property specifies the message to be processed.

**Input and Output Properties**

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

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

- [InputFile](#inputfile-property-salsa20-component)
- InputMessage

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

- [OutputFile](#outputfile-property-salsa20-component)
- [OutputMessage](#outputmessage-property-salsa20-component): The output data is written to this property if no other destination is specified.

## Data Type

**[]byte**

# IV Property ([Salsa20](#salsa20-component) Component)

The initialization vector (IV).

## Syntax

*Go Syntax*

```text
func (obj *Salsa20) IV() ([]byte, error)func (obj *Salsa20) SetIV(value []byte) error
```

## Default Value

""

## Remarks

This property specifies the initialization vector (IV). This is also referred to as the nonce. By default this property is empty and the struct will automatically generate a new IV value if [KeyPassword](#keypassword-property-salsa20-component) or [Key](#key-property-salsa20-component) is set before [Encrypt](#encrypt-method-salsa20-component) or [EncryptBlock](#encryptblock-method-salsa20-component) is called.

**XSalsa Notes:**

When *Algorithm* is set to XSalsa the length of the IV must be 192 bits in length (24 bytes).

**Salsa Notes:**

When *Algorithm* is set to Salsa the length of the IV must be 64 bits in length (8 bytes).

## Data Type

**[]byte**

# Key Property ([Salsa20](#salsa20-component) Component)

The secret key for the symmetric algorithm.

## Syntax

*Go Syntax*

```text
func (obj *Salsa20) Key() ([]byte, error)func (obj *Salsa20) SetKey(value []byte) error
```

## Default Value

""

## Remarks

This secret key is used both for encryption and decryption. The secret key should be known only to the sender and the receiver. This key must be 256 bits in length (32 bytes).

If this property is left empty and [KeyPassword](#keypassword-property-salsa20-component) is specified, a Key value will be generated by the struct as necessary.

## Data Type

**[]byte**

# KeyPassword Property ([Salsa20](#salsa20-component) Component)

A password to generate the Key and IV .

## Syntax

*Go Syntax*

```text
func (obj *Salsa20) KeyPassword() (string, error)func (obj *Salsa20) SetKeyPassword(value string) error
```

## Default Value

""

## Remarks

When this property is set the struct will calculate values for [Key](#key-property-salsa20-component) and [IV](#iv-property-salsa20-component) using the PKCS5 password digest algorithm. This provides a simpler alternative to creating and managing [Key](#key-property-salsa20-component) and [IV](#iv-property-salsa20-component) values directly.

## Data Type

**string**

# OutputFile Property ([Salsa20](#salsa20-component) Component)

The output file when encrypting or decrypting.

## Syntax

*Go Syntax*

```text
func (obj *Salsa20) OutputFile() (string, error)func (obj *Salsa20) SetOutputFile(value string) error
```

## Default Value

""

## Remarks

This property specifies the file to which the output will be written when [Encrypt](#encrypt-method-salsa20-component) or [Decrypt](#decrypt-method-salsa20-component) is called. This may be set to an absolute or relative path.

This property is only applicable to [Encrypt](#encrypt-method-salsa20-component) and [Decrypt](#decrypt-method-salsa20-component).

**Input and Output Properties**

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

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

- [InputFile](#inputfile-property-salsa20-component)
- [InputMessage](#inputmessage-property-salsa20-component)

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

- OutputFile
- [OutputMessage](#outputmessage-property-salsa20-component): The output data is written to this property if no other destination is specified.

## Data Type

**string**

# OutputMessage Property ([Salsa20](#salsa20-component) Component)

The output message after processing.

## Syntax

*Go Syntax*

```text
func (obj *Salsa20) OutputMessage() ([]byte, error)
```

## Default Value

""

## Remarks

This property will be populated with the output from the operation if [OutputFile](#outputfile-property-salsa20-component) is not set.

**Input and Output Properties**

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

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

- [InputFile](#inputfile-property-salsa20-component)
- [InputMessage](#inputmessage-property-salsa20-component)

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

- [OutputFile](#outputfile-property-salsa20-component)
- OutputMessage: The output data is written to this property if no other destination is specified.

This property is read-only.

## Data Type

**[]byte**

# Overwrite Property ([Salsa20](#salsa20-component) Component)

Indicates whether or not the class should overwrite files.

## Syntax

*Go Syntax*

```text
func (obj *Salsa20) Overwrite() (bool, error)func (obj *Salsa20) SetOverwrite(value bool) error
```

## Default Value

false

## Remarks

This property indicates whether or not the struct will overwrite [OutputFile](#outputfile-property-salsa20-component). If Overwrite is False, an error will be thrown whenever [OutputFile](#outputfile-property-salsa20-component) exists before an operation. The default value is False.

## Data Type

**bool**

# UseHex Property ([Salsa20](#salsa20-component) Component)

Whether input or output is hex encoded.

## Syntax

*Go Syntax*

```text
func (obj *Salsa20) UseHex() (bool, error)func (obj *Salsa20) SetUseHex(value bool) error
```

## Default Value

false

## Remarks

This property specifies whether the encrypted data is hex encoded.

If set to True, when [Encrypt](#encrypt-method-salsa20-component) is called the struct will perform the encryption as normal and then hex encode the output. [OutputMessage](#outputmessage-property-salsa20-component) or [OutputFile](#outputfile-property-salsa20-component) will hold hex encoded data.

If set to True, when [Decrypt](#decrypt-method-salsa20-component) is called the struct will expect [InputMessage](#inputmessage-property-salsa20-component) or [InputFile](#inputfile-property-salsa20-component) to hold hex encoded data. The struct will then hex decode the data and perform decryption as normal.

## Data Type

**bool**

# Config Method ([Salsa20](#salsa20-component) Component)

Sets or retrieves a configuration setting.

## Syntax

*Go Syntax*

```text
func (obj *Salsa20) Config(ConfigurationString string) (string, error)
```

## Remarks

Config is a generic method available in every struct. It is used to set and retrieve [configuration settings](#config-settings-salsa20-component) for the struct.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the struct, access to these *internal properties* is provided through the Config method.

To set a configuration setting named *PROPERTY*, you must call *Config("PROPERTY=VALUE")*, where *VALUE* is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a [configuration setting](#config-settings-salsa20-component), you must call *Config("PROPERTY")*. The value will be returned as a string.

# Decrypt Method ([Salsa20](#salsa20-component) Component)

Decrypts the data.

## Syntax

*Go Syntax*

```text
func (obj *Salsa20) Decrypt() error
```

## Remarks

Decrypt will decrypt the specified data. The following properties are applicable:

- [IV](#iv-property-salsa20-component) (required)
- [Key](#key-property-salsa20-component) (required)

**Input and Output Properties**

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

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

- [InputFile](#inputfile-property-salsa20-component)
- [InputMessage](#inputmessage-property-salsa20-component)

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

- [OutputFile](#outputfile-property-salsa20-component)
- [OutputMessage](#outputmessage-property-salsa20-component): The output data is written to this property if no other destination is specified.

**Additional Notes**

The [Key](#key-property-salsa20-component) property must be set to the 256 bit (32 byte) value originally used to encrypt the data. [IV](#iv-property-salsa20-component) must be set to the original IV value used to encrypt the data.

If using a password, [KeyPassword](#keypassword-property-salsa20-component) must be set to the same [KeyPassword](#keypassword-property-salsa20-component) used when encrypting the data. This will automatically generate both [Key](#key-property-salsa20-component) and [IV](#iv-property-salsa20-component) when Decrypt is called.

During decryption the [Progress](#progress-event-salsa20-component) event will fire as data is decrypted.

**Decrypt Example**

```csharp
Salsa20 salsa = new Salsa20();

//32 Bytes
salsa.KeyB = new byte[] { 0xBB, 0x76, 0x17, 0xC9, 0x05, 0x73, 0x4A, 0x8D, 0x59, 0x9D, 0x7B, 0x0D, 0x86, 0x2A, 0x03, 0x82, 0x50, 0x6A, 0x70, 0xFB, 0xA8, 0x56, 0x47, 0x1B, 0x1E, 0x68, 0x0B, 0x2B, 0x34, 0x18, 0x0F, 0xE2 };

//24 Bytes
salsa.IVB = new byte[] { 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7, 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7 };

salsa.InputMessageB = new byte[] { 0x06, 0xF4, 0xD9, 0xB4, 0x67, 0x31, 0x1C, 0x1E, 0x8E, 0xD6, 0xB5, 0x6B };
salsa.Decrypt();

Console.WriteLine(salsa.OutputMessage); //outputs "hello salsa!"
```

# DecryptBlock Method ([Salsa20](#salsa20-component) Component)

Decrypts a block and returns the decrypted data.

## Syntax

*Go Syntax*

```text
func (obj *Salsa20) DecryptBlock(InputBuffer []byte) ([]byte, error)
```

## Remarks

DecryptBlock will decrypt the input data and return the decrypted block. The decrypted block will always be the same length as the encrypted data. The following properties are applicable:

- [IV](#iv-property-salsa20-component) (required)
- [Key](#key-property-salsa20-component) (required)

*InputBuffer* specifies the input data to decrypt.

**DecryptBlock Example**

```csharp
Salsa20 salsa = new Salsa20();

//32 Bytes
salsa.KeyB = new byte[] { 0xBB, 0x76, 0x17, 0xC9, 0x05, 0x73, 0x4A, 0x8D, 0x59, 0x9D, 0x7B, 0x0D, 0x86, 0x2A, 0x03, 0x82, 0x50, 0x6A, 0x70, 0xFB, 0xA8, 0x56, 0x47, 0x1B, 0x1E, 0x68, 0x0B, 0x2B, 0x34, 0x18, 0x0F, 0xE2 };

//24 Bytes
salsa.IVB = new byte[] { 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7, 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7 };

byte[] tempDecryptedBlock;

//Decrypt any number of blocks of any size
tempDecryptedBlock = salsa.DecryptBlock(part1);
tempDecryptedBlock = salsa.DecryptBlock(part2);
```

# Encrypt Method ([Salsa20](#salsa20-component) Component)

Encrypts the data.

## Syntax

*Go Syntax*

```text
func (obj *Salsa20) Encrypt() error
```

## Remarks

Encrypt will encrypt the specified data. The following properties are applicable:

- [IV](#iv-property-salsa20-component) (required)
- [Key](#key-property-salsa20-component) (required)

**Input and Output Properties**

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

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

- [InputFile](#inputfile-property-salsa20-component)
- [InputMessage](#inputmessage-property-salsa20-component)

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

- [OutputFile](#outputfile-property-salsa20-component)
- [OutputMessage](#outputmessage-property-salsa20-component): The output data is written to this property if no other destination is specified.

**Additional Notes**

The [Key](#key-property-salsa20-component) property must be set to a 256 bit (32 byte) value. This is the only allowed value for ChaCha20. If [KeyPassword](#keypassword-property-salsa20-component) is set both [Key](#key-property-salsa20-component) and [IV](#iv-property-salsa20-component) will be automatically generated when Encrypt is called.

The [IV](#iv-property-salsa20-component) must be set to a 192 bit (24 byte) value when [Algorithm](#algorithm-property-salsa20-component) is set to XSalsa. The [IV](#iv-property-salsa20-component) must be set to a 64 bit (8 byte) value when [Algorithm](#algorithm-property-salsa20-component) is set to Salsa.

If [IV](#iv-property-salsa20-component) is not set a value will automatically be generated by the struct when Encrypt is called.

During encryption the [Progress](#progress-event-salsa20-component) event will fire as data is encrypted.

**Encrypt Example**

```csharp
Salsa20 salsa = new Salsa20();

//32 Bytes
salsa.KeyB = new byte[] { 0xBB, 0x76, 0x17, 0xC9, 0x05, 0x73, 0x4A, 0x8D, 0x59, 0x9D, 0x7B, 0x0D, 0x86, 0x2A, 0x03, 0x82, 0x50, 0x6A, 0x70, 0xFB, 0xA8, 0x56, 0x47, 0x1B, 0x1E, 0x68, 0x0B, 0x2B, 0x34, 0x18, 0x0F, 0xE2 };

//24 Bytes
salsa.IVB = new byte[] { 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7, 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7 };

salsa.InputMessage = "hello salsa!";
salsa.Encrypt();

//salsa.OutputMessageB contains the byte[] of the encrypted data. The above code produces the following encrypted bytes.
// { 0x06, 0xF4, 0xD9, 0xB4, 0x67, 0x31, 0x1C, 0x1E, 0x8E, 0xD6, 0xB5, 0x6B }
```

# EncryptBlock Method ([Salsa20](#salsa20-component) Component)

Encrypts data and returns the encrypted block.

## Syntax

*Go Syntax*

```text
func (obj *Salsa20) EncryptBlock(InputBuffer []byte) ([]byte, error)
```

## Remarks

EncryptBlock will encrypt the input data and return the encrypted block. The encrypted block will always be the same length as the decrypted data. The following properties are applicable:

- [IV](#iv-property-salsa20-component) (required)
- [Key](#key-property-salsa20-component) (required)

*InputBuffer* specifies the input data to encrypt.

**EncryptBlock Example**

```csharp
Salsa20 salsa = new Salsa20();

//32 Bytes
salsa.KeyB = new byte[] { 0xBB, 0x76, 0x17, 0xC9, 0x05, 0x73, 0x4A, 0x8D, 0x59, 0x9D, 0x7B, 0x0D, 0x86, 0x2A, 0x03, 0x82, 0x50, 0x6A, 0x70, 0xFB, 0xA8, 0x56, 0x47, 0x1B, 0x1E, 0x68, 0x0B, 0x2B, 0x34, 0x18, 0x0F, 0xE2 };

//24 Bytes
salsa.IVB = new byte[] { 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7, 0x0D, 0xE4, 0x43, 0x40, 0x29, 0xAD, 0x70, 0x7D, 0x7B, 0x32, 0xB5, 0xC7 };

byte[] tempEncryptedBlock;

//Encrypt any number of blocks of any size
tempEncryptedBlock = salsa.EncryptBlock(part1);
tempEncryptedBlock = salsa.EncryptBlock(part2);
```

# Reset Method ([Salsa20](#salsa20-component) Component)

Resets the class.

## Syntax

*Go Syntax*

```text
func (obj *Salsa20) Reset() error
```

## Remarks

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

# Error Event ([Salsa20](#salsa20-component) Component)

Fired when information is available about errors during data delivery.

## Syntax

*Go Syntax*

```text
// Salsa20ErrorEventArgs carries the Salsa20 Error event's parameters.
type Salsa20ErrorEventArgs struct {...}

func (args *Salsa20ErrorEventArgs) ErrorCode() int32
func (args *Salsa20ErrorEventArgs) Description() string
// Salsa20ErrorEvent defines the signature of the Salsa20 Error event's handler function.
type Salsa20ErrorEvent func(sender *Salsa20, args *Salsa20ErrorEventArgs)

func (obj *Salsa20) GetOnErrorHandler() Salsa20ErrorEvent
func (obj *Salsa20) SetOnErrorHandler(handlerFunc Salsa20ErrorEvent)
```

## Remarks

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

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-salsa20-component) section.

# Progress Event ([Salsa20](#salsa20-component) Component)

Fired as progress is made.

## Syntax

*Go Syntax*

```text
// Salsa20ProgressEventArgs carries the Salsa20 Progress event's parameters.
type Salsa20ProgressEventArgs struct {...}

func (args *Salsa20ProgressEventArgs) BytesProcessed() int64
func (args *Salsa20ProgressEventArgs) PercentProcessed() int32
// Salsa20ProgressEvent defines the signature of the Salsa20 Progress event's handler function.
type Salsa20ProgressEvent func(sender *Salsa20, args *Salsa20ProgressEventArgs)

func (obj *Salsa20) GetOnProgressHandler() Salsa20ProgressEvent
func (obj *Salsa20) SetOnProgressHandler(handlerFunc Salsa20ProgressEvent)
```

## Remarks

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

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

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

# Config Settings ([Salsa20](#salsa20-component) Component)

 The struct accepts one or more of the following *configuration settings*. Configuration settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the struct, access to these *internal properties* is provided through the [Config](#config-method-salsa20-component) method.

### XSalsa20 Config Settings

**EncryptedDataEncoding**: The encoding of the encrypted input or output data.This configuration setting specifies how the encrypted data is encoded (if at all).

When [Encrypt](#encrypt-method-salsa20-component) is called the struct will perform the encryption as normal and then encode the output as specified here. [OutputMessage](#outputmessage-property-salsa20-component) or [OutputFile](#outputfile-property-salsa20-component) will hold the encoded data.

When [Decrypt](#decrypt-method-salsa20-component) is called the struct will expect [InputMessage](#inputmessage-property-salsa20-component) or [InputFile](#inputfile-property-salsa20-component) to hold the encoded data as specified here. The struct will then decode the data and perform decryption as normal.

Possible values are:

- 0 (none - default)
- 1 (Base64)
- 2 (Hex)
- 3 (Base64URL)

**IncludeIV**: Whether to prepend the IV to the output data and read the IV from the input data.If this config is true, the IV will be automatically prepended to the output data when calling [Encrypt](#encrypt-method-salsa20-component). When calling [Decrypt](#decrypt-method-salsa20-component) and this setting is True, the IV is automatically extracted form the ciphertext. The default value is False.

**KeyPasswordAlgorithm**: The hash algorithm used to derive the Key and IV from the KeyPassword property.This configuration setting specifies which hash algorithm will be used when deriving the [Key](#key-property-salsa20-component) and [IV](#iv-property-salsa20-component) from [KeyPassword](#keypassword-property-salsa20-component). The default value is "MD5". Possible values are:

- "SHA1"
- "MD2"
- "MD5" (default)
- "HMAC-SHA1"
- "HMAC-SHA224"
- "HMAC-SHA256"
- "HMAC-SHA384"
- "HMAC-SHA512"
- "HMAC-MD5"
- "HMAC-RIPEMD160"

When using any HMAC algorithm the PBKDF#2 method from RFC 2898 is used. Any other algorithm uses PBKDF#1 from the same RFC.

**KeyPasswordIterations**: The number of iterations performed when using KeyPassword to derive the Key and IV.This configuration setting specifies the number of iterations performed when using [KeyPassword](#keypassword-property-salsa20-component) to calculate values for [Key](#key-property-salsa20-component) and [IV](#iv-property-salsa20-component). When using PBKDF#2 the default number of iterations is 10,000. When using PBKDF#1 the default number is 10.

**KeyPasswordSalt**: The salt value used in conjunction with the KeyPassword to derive the Key and IV.This configuration setting specifies the hex encoded salt value to be used along with the [KeyPassword](#keypassword-property-salsa20-component) when calculating values for [Key](#key-property-salsa20-component) and [IV](#iv-property-salsa20-component).

**SalsaRounds**: The number of rounds to perform.This setting specifies the number of rounds to perform. The default value is 20. The struct also supports 12 and 8 round variants which offer better performance but reduce overall security. This setting is only applicable when [Algorithm](#algorithm-property-salsa20-component) is set to *saSALSA20*. Possible values are:

- 20 (default - recommended)
- 12
- 8

### 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.

**CodePage**: The system code page used for Unicode to Multibyte translations.The default code page is Unicode UTF-8 (65001).

The following is a list of valid code page identifiers:

|  |  |
| --- | --- |
| Identifier | Name |
| 037 | IBM EBCDIC - U.S./Canada |
| 437 | OEM - United States |
| 500 | IBM EBCDIC - International |
| 708 | Arabic - ASMO 708 |
| 709 | Arabic - ASMO 449+, BCON V4 |
| 710 | Arabic - Transparent Arabic |
| 720 | Arabic - Transparent ASMO |
| 737 | OEM - Greek (formerly 437G) |
| 775 | OEM - Baltic |
| 850 | OEM - Multilingual Latin I |
| 852 | OEM - Latin II |
| 855 | OEM - Cyrillic (primarily Russian) |
| 857 | OEM - Turkish |
| 858 | OEM - Multilingual Latin I + Euro symbol |
| 860 | OEM - Portuguese |
| 861 | OEM - Icelandic |
| 862 | OEM - Hebrew |
| 863 | OEM - Canadian-French |
| 864 | OEM - Arabic |
| 865 | OEM - Nordic |
| 866 | OEM - Russian |
| 869 | OEM - Modern Greek |
| 870 | IBM EBCDIC - Multilingual/ROECE (Latin-2) |
| 874 | ANSI/OEM - Thai (same as 28605, ISO 8859-15) |
| 875 | IBM EBCDIC - Modern Greek |
| 932 | ANSI/OEM - Japanese, Shift-JIS |
| 936 | ANSI/OEM - Simplified Chinese (PRC, Singapore) |
| 949 | ANSI/OEM - Korean (Unified Hangul Code) |
| 950 | ANSI/OEM - Traditional Chinese (Taiwan; Hong Kong SAR, PRC) |
| 1026 | IBM EBCDIC - Turkish (Latin-5) |
| 1047 | IBM EBCDIC - Latin 1/Open System |
| 1140 | IBM EBCDIC - U.S./Canada (037 + Euro symbol) |
| 1141 | IBM EBCDIC - Germany (20273 + Euro symbol) |
| 1142 | IBM EBCDIC - Denmark/Norway (20277 + Euro symbol) |
| 1143 | IBM EBCDIC - Finland/Sweden (20278 + Euro symbol) |
| 1144 | IBM EBCDIC - Italy (20280 + Euro symbol) |
| 1145 | IBM EBCDIC - Latin America/Spain (20284 + Euro symbol) |
| 1146 | IBM EBCDIC - United Kingdom (20285 + Euro symbol) |
| 1147 | IBM EBCDIC - France (20297 + Euro symbol) |
| 1148 | IBM EBCDIC - International (500 + Euro symbol) |
| 1149 | IBM EBCDIC - Icelandic (20871 + Euro symbol) |
| 1200 | Unicode UCS-2 Little-Endian (BMP of ISO 10646) |
| 1201 | Unicode UCS-2 Big-Endian |
| 1250 | ANSI - Central European |
| 1251 | ANSI - Cyrillic |
| 1252 | ANSI - Latin I |
| 1253 | ANSI - Greek |
| 1254 | ANSI - Turkish |
| 1255 | ANSI - Hebrew |
| 1256 | ANSI - Arabic |
| 1257 | ANSI - Baltic |
| 1258 | ANSI/OEM - Vietnamese |
| 1361 | Korean (Johab) |
| 10000 | MAC - Roman |
| 10001 | MAC - Japanese |
| 10002 | MAC - Traditional Chinese (Big5) |
| 10003 | MAC - Korean |
| 10004 | MAC - Arabic |
| 10005 | MAC - Hebrew |
| 10006 | MAC - Greek I |
| 10007 | MAC - Cyrillic |
| 10008 | MAC - Simplified Chinese (GB 2312) |
| 10010 | MAC - Romania |
| 10017 | MAC - Ukraine |
| 10021 | MAC - Thai |
| 10029 | MAC - Latin II |
| 10079 | MAC - Icelandic |
| 10081 | MAC - Turkish |
| 10082 | MAC - Croatia |
| 12000 | Unicode UCS-4 Little-Endian |
| 12001 | Unicode UCS-4 Big-Endian |
| 20000 | CNS - Taiwan |
| 20001 | TCA - Taiwan |
| 20002 | Eten - Taiwan |
| 20003 | IBM5550 - Taiwan |
| 20004 | TeleText - Taiwan |
| 20005 | Wang - Taiwan |
| 20105 | IA5 IRV International Alphabet No. 5 (7-bit) |
| 20106 | IA5 German (7-bit) |
| 20107 | IA5 Swedish (7-bit) |
| 20108 | IA5 Norwegian (7-bit) |
| 20127 | US-ASCII (7-bit) |
| 20261 | T.61 |
| 20269 | ISO 6937 Non-Spacing Accent |
| 20273 | IBM EBCDIC - Germany |
| 20277 | IBM EBCDIC - Denmark/Norway |
| 20278 | IBM EBCDIC - Finland/Sweden |
| 20280 | IBM EBCDIC - Italy |
| 20284 | IBM EBCDIC - Latin America/Spain |
| 20285 | IBM EBCDIC - United Kingdom |
| 20290 | IBM EBCDIC - Japanese Katakana Extended |
| 20297 | IBM EBCDIC - France |
| 20420 | IBM EBCDIC - Arabic |
| 20423 | IBM EBCDIC - Greek |
| 20424 | IBM EBCDIC - Hebrew |
| 20833 | IBM EBCDIC - Korean Extended |
| 20838 | IBM EBCDIC - Thai |
| 20866 | Russian - KOI8-R |
| 20871 | IBM EBCDIC - Icelandic |
| 20880 | IBM EBCDIC - Cyrillic (Russian) |
| 20905 | IBM EBCDIC - Turkish |
| 20924 | IBM EBCDIC - Latin-1/Open System (1047 + Euro symbol) |
| 20932 | JIS X 0208-1990 & 0121-1990 |
| 20936 | Simplified Chinese (GB2312) |
| 21025 | IBM EBCDIC - Cyrillic (Serbian, Bulgarian) |
| 21027 | Extended Alpha Lowercase |
| 21866 | Ukrainian (KOI8-U) |
| 28591 | ISO 8859-1 Latin I |
| 28592 | ISO 8859-2 Central Europe |
| 28593 | ISO 8859-3 Latin 3 |
| 28594 | ISO 8859-4 Baltic |
| 28595 | ISO 8859-5 Cyrillic |
| 28596 | ISO 8859-6 Arabic |
| 28597 | ISO 8859-7 Greek |
| 28598 | ISO 8859-8 Hebrew |
| 28599 | ISO 8859-9 Latin 5 |
| 28605 | ISO 8859-15 Latin 9 |
| 29001 | Europa 3 |
| 38598 | ISO 8859-8 Hebrew |
| 50220 | ISO 2022 Japanese with no halfwidth Katakana |
| 50221 | ISO 2022 Japanese with halfwidth Katakana |
| 50222 | ISO 2022 Japanese JIS X 0201-1989 |
| 50225 | ISO 2022 Korean |
| 50227 | ISO 2022 Simplified Chinese |
| 50229 | ISO 2022 Traditional Chinese |
| 50930 | Japanese (Katakana) Extended |
| 50931 | US/Canada and Japanese |
| 50933 | Korean Extended and Korean |
| 50935 | Simplified Chinese Extended and Simplified Chinese |
| 50936 | Simplified Chinese |
| 50937 | US/Canada and Traditional Chinese |
| 50939 | Japanese (Latin) Extended and Japanese |
| 51932 | EUC - Japanese |
| 51936 | EUC - Simplified Chinese |
| 51949 | EUC - Korean |
| 51950 | EUC - Traditional Chinese |
| 52936 | HZ-GB2312 Simplified Chinese |
| 54936 | Windows XP: GB18030 Simplified Chinese (4 Byte) |
| 57002 | ISCII Devanagari |
| 57003 | ISCII Bengali |
| 57004 | ISCII Tamil |
| 57005 | ISCII Telugu |
| 57006 | ISCII Assamese |
| 57007 | ISCII Oriya |
| 57008 | ISCII Kannada |
| 57009 | ISCII Malayalam |
| 57010 | ISCII Gujarati |
| 57011 | ISCII Punjabi |
| 65000 | Unicode UTF-7 |
| 65001 | Unicode UTF-8 |

 The following is a list of valid code page identifiers for Mac OS only:

|  |  |
| --- | --- |
| Identifier | Name |
| 1 | ASCII |
| 2 | NEXTSTEP |
| 3 | JapaneseEUC |
| 4 | UTF8 |
| 5 | ISOLatin1 |
| 6 | Symbol |
| 7 | NonLossyASCII |
| 8 | ShiftJIS |
| 9 | ISOLatin2 |
| 10 | Unicode |
| 11 | WindowsCP1251 |
| 12 | WindowsCP1252 |
| 13 | WindowsCP1253 |
| 14 | WindowsCP1254 |
| 15 | WindowsCP1250 |
| 21 | ISO2022JP |
| 30 | MacOSRoman |
| 10 | UTF16String |
| 0x90000100 | UTF16BigEndian |
| 0x94000100 | UTF16LittleEndian |
| 0x8c000100 | UTF32String |
| 0x98000100 | UTF32BigEndian |
| 0x9c000100 | UTF32LittleEndian |
| 65536 | Proprietary |

**LicenseInfo**: Information about the current license.When queried, this setting will return a string containing information about the license this instance of a struct 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*.

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

Setting this configuration setting to *true* tells the struct 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.

 To use the system security libraries for Linux, OpenSSL support must be enabled. For more information on how to enable OpenSSL, please refer to the [OpenSSL Notes](platforms.md) section.

# Trappable Errors ([Salsa20](#salsa20-component) Component)

### XSalsa20 Errors

|  |  |
| --- | --- |
| 101 | Unsupported algorithm. |
| 102 | No Key specified. |
| 103 | No IV specified. |
| 104 | Cannot read or write file. |
| 107 | Block size is not valid for this algorithm. |
| 108 | Key size is not valid for this algorithm. |
| 111 | OutputFile already exists and Overwrite is False. |
| 121 | The specified key is invalid. |
| 123 | IV size is not valid for this algorithm. |
| 304 | Cannot write file. |
| 305 | Cannot read file. |
| 306 | Cannot create file. |
| 2004 | Invalid padding. This may be an indication that the key is incorrect. |
| 130 | Invalid number of rounds. The number of rounds used when [Algorithm](#algorithm-property-salsa20-component) is set to Salsa must be 8, 12, or 20. |