Key Class

Represents a symmetric key or an asymmetric private key.

public sealed class Key : IDisposable

Constructors

Key(Algorithm, in KeyCreationParameters)

Initializes a new instance of the Key class with a random key.

public Key(
    Algorithm algorithm,
    in KeyCreationParameters creationParameters = default)

Parameters

algorithm
The algorithm for the key.
creationParameters
A KeyCreationParameters value that specifies advanced parameters for the creation of the Key instance.

Exceptions

ArgumentNullException
algorithm is null.
NotSupportedException
The specified algorithm does not use keys.

Properties

Algorithm

Gets the algorithm for the key.

public Algorithm Algorithm { get; }

Property Value

An instance of the Algorithm class.

ExportPolicy

Gets the export policy for the key.

public KeyExportPolicies ExportPolicy { get; }

Property Value

A bitwise combination of KeyExportPolicies values that specifies the export policy for the key.

HasPublicKey

Specifies whether the current instance of the Key class represents a private key.

public bool HasPublicKey { get; }

Property Value

true if the current instance is a represents a private key; otherwise, false.

PublicKey

Gets the public key if the current instance of the Key class represents a private key.

public PublicKey PublicKey { get; }

Property Value

An instance of the PublicKey class if the current instance represents a private key.

Exceptions

InvalidOperationException
The current instance does not represent a private key.

Remarks

This property throws an InvalidOperationException if the HasPublicKey property returns false.

Size

Gets the size of the key.

public int Size { get; }

Property Value

The key size, in bytes.

Static Methods

Create(Algorithm, in KeyCreationParameters)

Creates a new instance of the Key class with a random key.

public static Key Create(
    Algorithm algorithm,
    in KeyCreationParameters creationParameters = default)

Parameters

algorithm
The algorithm for the key.
creationParameters
A KeyCreationParameters value that specifies advanced parameters for the creation of the Key instance.

Return Value

A new instance of the Key class that represents the new key.

Exceptions

ArgumentNullException
algorithm is null.
NotSupportedException
The specified algorithm does not use keys.

Import(Algorithm, ReadOnlySpan<byte>, KeyBlobFormat, in KeyCreationParameters)

Imports the specified key BLOB in the specified format.

public static Key Import(
    Algorithm algorithm,
    ReadOnlySpan<byte> blob,
    KeyBlobFormat format,
    in KeyCreationParameters creationParameters = default)

Parameters

algorithm
The algorithm for the imported key.
blob
The key BLOB to import.
format
One of the KeyBlobFormat values that specifies the format of the key BLOB.
creationParameters
A KeyCreationParameters value that specifies advanced parameters for the creation of the Key instance.

Return Value

A new instance of the Key class that represents the imported key.

Exceptions

ArgumentNullException
algorithm is null.
ArgumentException
The specified format is not supported by the specified algorithm.
FormatException
The key BLOB is not in the correct format.
NotSupportedException
The specified algorithm does not support importing keys.

TryImport(Algorithm, ReadOnlySpan<byte>, KeyBlobFormat, out Key?, in KeyCreationParameters)

Attempts to import the specified key BLOB in the specified format.

public static bool TryImport(
    Algorithm algorithm,
    ReadOnlySpan<byte> blob,
    KeyBlobFormat format,
    out Key? result,
    in KeyCreationParameters creationParameters = default)

Parameters

algorithm
The algorithm for the imported key.
blob
The key BLOB to import.
format
One of the KeyBlobFormat values that specifies the format of the key BLOB.
result
When this method returns, contains a new instance of the Key class that represents the imported key, or null if the import fails.
creationParameters
A KeyCreationParameters value that specifies advanced parameters for the creation of the Key instance.

Return Value

true if the import succeeds; otherwise, false.

Exceptions

ArgumentNullException
algorithm is null.
ArgumentException
The specified format is not supported by the specified algorithm.
NotSupportedException
The specified algorithm does not support importing keys.

Methods

Dispose()

Securely erases the key from memory and releases all resources used by the current instance of the Key class.

public void Dispose();

Export(KeyBlobFormat)

Exports the key as a BLOB in the specified format and returns it as an array of bytes.

public byte[] Export(
    KeyBlobFormat format)

Parameters

format
One of the KeyBlobFormat values that specifies the format of the key BLOB.

Return Value

A BLOB that contains the key in the specified format.

Exceptions

ArgumentException
The algorithm for the key does not support the specified format.
InvalidOperationException
The export policy for the key do not allow the key to be exported.
NotSupportedException
The algorithm for the key does not support exporting keys.
ObjectDisposedException
The key has been disposed.

GetExportBlobSize(KeyBlobFormat)

Returns the BLOB size of the key if it were exported in the specified format.

public int GetExportBlobSize(
    KeyBlobFormat format)

Parameters

format
One of the KeyBlobFormat values that specifies the format of the key BLOB.

Return Value

The size (in bytes) of the key if it were exported as a BLOB in the specified format.

Exceptions

ArgumentException
The algorithm for the key does not support the specified format.
NotSupportedException
The algorithm for the key does not support exporting keys.
ObjectDisposedException
The key has been disposed.

TryExport(KeyBlobFormat, Span<byte>, out int)

Exports the specified key BLOB in the specified format and attempts to fill the specified span of bytes with the BLOB.

public bool TryExport(
    KeyBlobFormat format,
    Span<byte> blob,
    out int blobSize)

Parameters

format
One of the KeyBlobFormat values that specifies the format of the key BLOB.
blob
The span to fill with the exported public key BLOB. The length of the span must be greater than or equal to GetExportBlobSize(format).
blobSize
When this method returns, contains the number of bytes written into the output span.

Return Value

false if there is not enough space in the output span to write the key BLOB; otherwise true.

Exceptions

ArgumentException
The algorithm for the key does not support the specified format.
InvalidOperationException
The export policy for the key do not allow the key to be exported.
NotSupportedException
The algorithm for the key does not support exporting keys.
ObjectDisposedException
The key has been disposed.

Thread Safety

Any public static members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

See Also