Table of Contents

Class CryptoStreamSalsa20

Namespace
LibSodium
Assembly
LibSodium.Net.dll

Provides high-level access to the Salsa20 stream cipher.

public static class CryptoStreamSalsa20
Inheritance
CryptoStreamSalsa20
Inherited Members

Fields

BlockLen

Block size of the keystream in bytes (64).

public static readonly int BlockLen

Field Value

int

KeyLen

Length of the secret key in bytes (32).

public static readonly int KeyLen

Field Value

int

NonceLen

Length of the nonce in bytes (8).

public static readonly int NonceLen

Field Value

int

Methods

Decrypt(SecureMemory<byte>, ReadOnlySpan<byte>, Stream, Stream)

Decrypts a stream using the Salsa20 stream cipher.

public static void Decrypt(SecureMemory<byte> key, ReadOnlySpan<byte> nonce, Stream input, Stream output)

Parameters

key SecureMemory<byte>

The secret key. Must be exactly 32 bytes long.

nonce ReadOnlySpan<byte>

The nonce used during encryption. Must be exactly 8 bytes long.

input Stream

The stream containing ciphertext to decrypt.

output Stream

The stream to receive the decrypted data.

Exceptions

ArgumentException

Thrown if key or nonce are invalid.

Decrypt(SecureMemory<byte>, ReadOnlySpan<byte>, ReadOnlySpan<byte>, Span<byte>, ulong)

Decrypts the given ciphertext using the Salsa20 stream cipher, with the provided key and nonce.

public static void Decrypt(SecureMemory<byte> key, ReadOnlySpan<byte> nonce, ReadOnlySpan<byte> ciphertext, Span<byte> plaintext, ulong initialCounter = 0)

Parameters

key SecureMemory<byte>

The secret key. Must be exactly 32 bytes long.

nonce ReadOnlySpan<byte>

The nonce used during encryption. Must be exactly 8 bytes long.

ciphertext ReadOnlySpan<byte>

The ciphertext to decrypt (produced by XOR with keystream).

plaintext Span<byte>

The output buffer to receive the decrypted plaintext. Must be at least as long as ciphertext.

initialCounter ulong

The starting block index for the keystream (each block is 64 bytes). Use this to skip blocks, resume encryption, or decrypt from a specific offset. Defaults to 0.

Remarks

Decryption is symmetric: it re-generates the same keystream and XORs it with the ciphertext.

Exceptions

ArgumentException

Thrown if any input length is invalid.

Decrypt(ReadOnlySpan<byte>, ReadOnlySpan<byte>, Stream, Stream)

Decrypts a stream using the Salsa20 stream cipher.

public static void Decrypt(ReadOnlySpan<byte> key, ReadOnlySpan<byte> nonce, Stream input, Stream output)

Parameters

key ReadOnlySpan<byte>

The secret key. Must be exactly 32 bytes long.

nonce ReadOnlySpan<byte>

The nonce used during encryption. Must be exactly 8 bytes long.

input Stream

The stream containing ciphertext to decrypt.

output Stream

The stream to receive the decrypted data.

Exceptions

ArgumentException

Thrown if key or nonce are invalid.

Decrypt(ReadOnlySpan<byte>, ReadOnlySpan<byte>, ReadOnlySpan<byte>, Span<byte>, ulong)

Decrypts the given ciphertext using the Salsa20 stream cipher, with the provided key and nonce.

public static void Decrypt(ReadOnlySpan<byte> key, ReadOnlySpan<byte> nonce, ReadOnlySpan<byte> ciphertext, Span<byte> plaintext, ulong initialCounter = 0)

Parameters

key ReadOnlySpan<byte>

The secret key. Must be exactly 32 bytes long.

nonce ReadOnlySpan<byte>

The nonce used during encryption. Must be exactly 8 bytes long.

ciphertext ReadOnlySpan<byte>

The ciphertext to decrypt (produced by XOR with keystream).

plaintext Span<byte>

The output buffer to receive the decrypted plaintext. Must be at least as long as ciphertext.

initialCounter ulong

The starting block index for the keystream (each block is 64 bytes). Use this to skip blocks, resume encryption, or decrypt from a specific offset. Defaults to 0.

Remarks

Decryption is symmetric: it re-generates the same keystream and XORs it with the ciphertext.

Exceptions

ArgumentException

Thrown if any input length is invalid.

DecryptAsync(SecureMemory<byte>, ReadOnlyMemory<byte>, Stream, Stream, CancellationToken)

Asynchronously decrypts a stream using the Salsa20 stream cipher.

public static Task DecryptAsync(SecureMemory<byte> key, ReadOnlyMemory<byte> nonce, Stream input, Stream output, CancellationToken cancellationToken = default)

Parameters

key SecureMemory<byte>

The secret key. Must be exactly 32 bytes.

nonce ReadOnlyMemory<byte>

The nonce used during encryption. Must be 8 bytes.

input Stream

The readable stream with ciphertext.

output Stream

The writable stream to receive decrypted data.

cancellationToken CancellationToken

Optional token to cancel the async operation.

Returns

Task

A task that represents the asynchronous operation.

DecryptAsync(ReadOnlyMemory<byte>, ReadOnlyMemory<byte>, Stream, Stream, CancellationToken)

Asynchronously decrypts a stream using the Salsa20 stream cipher.

public static Task DecryptAsync(ReadOnlyMemory<byte> key, ReadOnlyMemory<byte> nonce, Stream input, Stream output, CancellationToken cancellationToken = default)

Parameters

key ReadOnlyMemory<byte>

The secret key. Must be exactly 32 bytes.

nonce ReadOnlyMemory<byte>

The nonce used during encryption. Must be 8 bytes.

input Stream

The readable stream with ciphertext.

output Stream

The writable stream to receive decrypted data.

cancellationToken CancellationToken

Optional token to cancel the async operation.

Returns

Task

A task that represents the asynchronous operation.

Encrypt(SecureMemory<byte>, ReadOnlySpan<byte>, Stream, Stream)

Encrypts a stream using the Salsa20 stream cipher.

public static void Encrypt(SecureMemory<byte> key, ReadOnlySpan<byte> nonce, Stream input, Stream output)

Parameters

key SecureMemory<byte>

The secret key. Must be exactly 32 bytes long.

nonce ReadOnlySpan<byte>

The nonce. Must be exactly 8 bytes long.

input Stream

The stream containing plaintext data to encrypt.

output Stream

The stream to receive the encrypted data.

Exceptions

ArgumentException

Thrown if key or nonce are invalid.

Encrypt(SecureMemory<byte>, ReadOnlySpan<byte>, ReadOnlySpan<byte>, Span<byte>, ulong)

Encrypts the given plaintext using the Salsa20 stream cipher, with the provided key and nonce.

public static void Encrypt(SecureMemory<byte> key, ReadOnlySpan<byte> nonce, ReadOnlySpan<byte> plaintext, Span<byte> ciphertext, ulong initialCounter = 0)

Parameters

key SecureMemory<byte>

The secret key. Must be exactly 32 bytes long.

nonce ReadOnlySpan<byte>

The nonce. Must be exactly 8 bytes long. Must never be reused with the same key.

plaintext ReadOnlySpan<byte>

The plaintext data to encrypt.

ciphertext Span<byte>

The output buffer to receive the encrypted data. Must be at least as long as plaintext.

initialCounter ulong

The starting block index for the keystream (each block is 64 bytes). Use this to skip blocks, resume encryption, or decrypt from a specific offset. Defaults to 0.

Remarks

This method XORs the plaintext with a keystream derived from the key and nonce.

Exceptions

ArgumentException

Thrown if any input length is invalid.

Encrypt(ReadOnlySpan<byte>, ReadOnlySpan<byte>, Stream, Stream)

Encrypts a stream using the Salsa20 stream cipher.

public static void Encrypt(ReadOnlySpan<byte> key, ReadOnlySpan<byte> nonce, Stream input, Stream output)

Parameters

key ReadOnlySpan<byte>

The secret key. Must be exactly 32 bytes long.

nonce ReadOnlySpan<byte>

The nonce. Must be exactly 8 bytes long.

input Stream

The stream containing plaintext data to encrypt.

output Stream

The stream to receive the encrypted data.

Exceptions

ArgumentException

Thrown if key or nonce are invalid.

Encrypt(ReadOnlySpan<byte>, ReadOnlySpan<byte>, ReadOnlySpan<byte>, Span<byte>, ulong)

Encrypts the given plaintext using the Salsa20 stream cipher, with the provided key and nonce.

public static void Encrypt(ReadOnlySpan<byte> key, ReadOnlySpan<byte> nonce, ReadOnlySpan<byte> plaintext, Span<byte> ciphertext, ulong initialCounter = 0)

Parameters

key ReadOnlySpan<byte>

The secret key. Must be exactly 32 bytes long.

nonce ReadOnlySpan<byte>

The nonce. Must be exactly 8 bytes long. Must never be reused with the same key.

plaintext ReadOnlySpan<byte>

The plaintext data to encrypt.

ciphertext Span<byte>

The output buffer to receive the encrypted data. Must be at least as long as plaintext.

initialCounter ulong

The starting block index for the keystream (each block is 64 bytes). Use this to skip blocks, resume encryption, or decrypt from a specific offset. Defaults to 0.

Remarks

This method XORs the plaintext with a keystream derived from the key and nonce.

Exceptions

ArgumentException

Thrown if any input length is invalid.

EncryptAsync(SecureMemory<byte>, ReadOnlyMemory<byte>, Stream, Stream, CancellationToken)

Asynchronously encrypts a stream using the Salsa20 stream cipher.

public static Task EncryptAsync(SecureMemory<byte> key, ReadOnlyMemory<byte> nonce, Stream input, Stream output, CancellationToken cancellationToken = default)

Parameters

key SecureMemory<byte>

The secret key. Must be exactly 32 bytes.

nonce ReadOnlyMemory<byte>

The nonce. Must be exactly 8 bytes.

input Stream

The readable stream with plaintext data.

output Stream

The writable stream to receive ciphertext.

cancellationToken CancellationToken

Optional token to cancel the async operation.

Returns

Task

A task that represents the asynchronous operation.

EncryptAsync(ReadOnlyMemory<byte>, ReadOnlyMemory<byte>, Stream, Stream, CancellationToken)

Asynchronously encrypts a stream using the Salsa20 stream cipher.

public static Task EncryptAsync(ReadOnlyMemory<byte> key, ReadOnlyMemory<byte> nonce, Stream input, Stream output, CancellationToken cancellationToken = default)

Parameters

key ReadOnlyMemory<byte>

The secret key. Must be exactly 32 bytes.

nonce ReadOnlyMemory<byte>

The nonce. Must be exactly 8 bytes.

input Stream

The readable stream with plaintext data.

output Stream

The writable stream to receive ciphertext.

cancellationToken CancellationToken

Optional token to cancel the async operation.

Returns

Task

A task that represents the asynchronous operation.

GenerateKeystream(SecureMemory<byte>, ReadOnlySpan<byte>, SecureMemory<byte>)

Generates a keystream of the specified length using the Salsa20 stream cipher.

public static void GenerateKeystream(SecureMemory<byte> output, ReadOnlySpan<byte> nonce, SecureMemory<byte> key)

Parameters

output SecureMemory<byte>

The buffer to receive the generated keystream.

nonce ReadOnlySpan<byte>

The nonce. Must be exactly 8 bytes.

key SecureMemory<byte>

The key. Must be exactly 32 bytes.

Exceptions

ArgumentException

Thrown if output is empty or lengths are invalid.

GenerateKeystream(Span<byte>, ReadOnlySpan<byte>, ReadOnlySpan<byte>)

Generates a keystream of the specified length using the Salsa20 stream cipher.

public static void GenerateKeystream(Span<byte> output, ReadOnlySpan<byte> nonce, ReadOnlySpan<byte> key)

Parameters

output Span<byte>

The buffer to receive the generated keystream.

nonce ReadOnlySpan<byte>

The nonce. Must be exactly 8 bytes.

key ReadOnlySpan<byte>

The key. Must be exactly 32 bytes.

Exceptions

ArgumentException

Thrown if output is empty or lengths are invalid.