ECDsaCng Class
Definition
Important
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Provides a Cryptography Next Generation (CNG) implementation of the Elliptic Curve Digital Signature Algorithm (ECDSA).
public ref class ECDsaCng sealed : System::Security::Cryptography::ECDsapublic sealed class ECDsaCng : System.Security.Cryptography.ECDsatype ECDsaCng = class
inherit ECDsaPublic NotInheritable Class ECDsaCng
Inherits ECDsa- Inheritance
Examples
The following example shows how to use the ECDsaCng class to sign a message and how to use the signature to verify that the message has not been altered.
using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;
class Alice
{
public static void Main(string[] args)
{
Bob bob = new Bob();
using (ECDsaCng dsa = new ECDsaCng())
{
dsa.HashAlgorithm = CngAlgorithm.Sha256;
bob.key = dsa.Key.Export(CngKeyBlobFormat.EccPublicBlob);
byte[] data = new byte[] { 21, 5, 8, 12, 207 };
byte[] signature = dsa.SignData(data);
bob.Receive(data, signature);
}
}
}
public class Bob
{
public byte[] key;
public void Receive(byte[] data, byte[] signature)
{
using (ECDsaCng ecsdKey = new ECDsaCng(CngKey.Import(key, CngKeyBlobFormat.EccPublicBlob)))
{
if (ecsdKey.VerifyData(data, signature))
Console.WriteLine("Data is good");
else
Console.WriteLine("Data is bad");
}
}
}
Imports System.IO
Imports System.Security.Cryptography
Imports System.Text
Class Alice
Public Shared Sub Main(ByVal args() As String)
Dim bob As New Bob()
If (True) Then
Using dsa As New ECDsaCng()
dsa.HashAlgorithm = CngAlgorithm.Sha256
bob.key = dsa.Key.Export(CngKeyBlobFormat.EccPublicBlob)
Dim data() As Byte = {21, 5, 8, 12, 207}
Dim signature As Byte() = dsa.SignData(data)
bob.Receive(data, signature)
End Using
End If
End Sub
End Class
Public Class Bob
Public key() As Byte
Public Sub Receive(ByVal data() As Byte, ByVal signature() As Byte)
Using ecsdKey As New ECDsaCng(CngKey.Import(key, CngKeyBlobFormat.EccPublicBlob))
If ecsdKey.VerifyData(data, signature) Then
Console.WriteLine("Data is good")
Else
Console.WriteLine("Data is bad")
End If
End Using
End Sub
End Class
Remarks
This class should only be used directly when doing platform interop with the Windows CNG library. When platform interop is not needed, you should use the ECDsa.Create factory methods instead of a specific derived implementation.
Constructors
| Name | Description |
|---|---|
| ECDsaCng() |
Initializes a new instance of the ECDsaCng class with a random key pair. |
| ECDsaCng(CngKey) |
Initializes a new instance of the ECDsaCng class by using the specified CngKey object. |
| ECDsaCng(ECCurve) |
Initializes a new instance of the ECDsaCng class whose public/private key pair is generated over the specified curve. |
| ECDsaCng(Int32) |
Initializes a new instance of the ECDsaCng class with a specified target key size. |
Fields
| Name | Description |
|---|---|
| KeySizeValue |
Represents the size, in bits, of the key modulus used by the asymmetric algorithm. (Inherited from AsymmetricAlgorithm) |
| LegalKeySizesValue |
Specifies the key sizes that are supported by the asymmetric algorithm. (Inherited from AsymmetricAlgorithm) |
Properties
| Name | Description |
|---|---|
| HashAlgorithm |
Gets or sets the hash algorithm to use when signing and verifying data. |
| Key |
Gets or sets the key to use when signing and verifying data. |
| KeyExchangeAlgorithm |
Gets the name of the key exchange algorithm. (Inherited from ECDsa) |
| KeySize |
Gets or sets the size, in bits, of the key modulus used by the asymmetric algorithm. (Inherited from AsymmetricAlgorithm) |
| LegalKeySizes |
Gets the key sizes that are supported by the asymmetric algorithm. (Inherited from AsymmetricAlgorithm) |
| SignatureAlgorithm |
Gets the name of the signature algorithm. (Inherited from ECDsa) |
Methods
| Name | Description |
|---|---|
| Clear() |
Releases all resources used by the AsymmetricAlgorithm class. (Inherited from AsymmetricAlgorithm) |
| Dispose() |
Releases all resources used by the current instance of the AsymmetricAlgorithm class. (Inherited from AsymmetricAlgorithm) |
| Dispose(Boolean) |
Releases the unmanaged resources used by the AsymmetricAlgorithm class and optionally releases the managed resources. (Inherited from AsymmetricAlgorithm) |
| Equals(Object) |
Determines whether the specified object is equal to the current object. (Inherited from Object) |
| ExportExplicitParameters(Boolean) |
Exports the key and explicit curve parameters used by the Elliptic curve cryptography (ECC) object into an ECParameters object. |
| ExportParameters(Boolean) |
Exports the key used by the Elliptic curve cryptography (ECC) object into an ECParameters object. If the key was created as a named curve, the Curve field contains named curve parameters; otherwise, it contains explicit parameters. |
| FromXmlString(String, ECKeyXmlFormat) |
Deserializes the key information from an XML string by using the specified format. |
| FromXmlString(String) |
This method is not implemented. |
| GenerateKey(ECCurve) |
Generates a new ephemeral public/private key pair for the specified curve, replacing the current key. |
| GetHashCode() |
Serves as the default hash function. (Inherited from Object) |
| GetType() |
Gets the Type of the current instance. (Inherited from Object) |
| HashData(Byte[], Int32, Int32, HashAlgorithmName) |
When overridden in a derived class, computes the hash value of the specified portion of a byte array by using the specified hashing algorithm. (Inherited from ECDsa) |
| HashData(Stream, HashAlgorithmName) |
When overridden in a derived class, computes the hash value of the specified binary stream by using the specified hashing algorithm. (Inherited from ECDsa) |
| ImportParameters(ECParameters) |
Replaces the existing key that the current instance is working with by creating a new CngKey for the parameters structure. |
| MemberwiseClone() |
Creates a shallow copy of the current Object. (Inherited from Object) |
| SignData(Byte[], HashAlgorithmName) |
Computes the hash value of the specified byte array using the specified hash algorithm and signs the resulting hash value. (Inherited from ECDsa) |
| SignData(Byte[], Int32, Int32, HashAlgorithmName) |
Computes the hash value of a portion of the specified byte array using the specified hash algorithm and signs the resulting hash value. (Inherited from ECDsa) |
| SignData(Byte[], Int32, Int32) |
Generates a digital signature for the specified length of data, beginning at the specified offset. |
| SignData(Byte[]) |
Generates a signature for the specified data. |
| SignData(Stream, HashAlgorithmName) |
Computes the hash value of the specified stream using the specified hash algorithm and signs the resulting hash value. (Inherited from ECDsa) |
| SignData(Stream) |
Generates a signature for the specified data stream, reading to the end of the stream. |
| SignHash(Byte[]) |
Generates a signature for the specified hash value. |
| ToString() |
Returns a string that represents the current object. (Inherited from Object) |
| ToXmlString(Boolean) |
This method is not implemented. |
| ToXmlString(ECKeyXmlFormat) |
Serializes the key information to an XML string by using the specified format. |
| VerifyData(Byte[], Byte[], HashAlgorithmName) |
Verifies that a digital signature is appropriate for the current key and provided data with a specified hash algorithm. (Inherited from ECDsa) |
| VerifyData(Byte[], Byte[]) |
Verifies the digital signature of the specified data. |
| VerifyData(Byte[], Int32, Int32, Byte[], HashAlgorithmName) |
Verifies that a digital signature is appropriate for the current key and provided portion of data with a specified hash algorithm. (Inherited from ECDsa) |
| VerifyData(Byte[], Int32, Int32, Byte[]) |
Verifies a signature for the specified length of data, beginning at the specified offset. |
| VerifyData(Stream, Byte[], HashAlgorithmName) |
Verifies that a digital signature is appropriate for the current key and provided data with a specified hash algorithm. (Inherited from ECDsa) |
| VerifyData(Stream, Byte[]) |
Verifies the digital signature of the specified data stream, reading to the end of the stream. |
| VerifyHash(Byte[], Byte[]) |
Verifies that a digital signature is appropriate for the current key and provided data hash. |
Explicit Interface Implementations
| Name | Description |
|---|---|
| IDisposable.Dispose() |
This API supports the product infrastructure and is not intended to be used directly from your code. For a description of this member, see Dispose(). (Inherited from AsymmetricAlgorithm) |