DSA Class

Definition

Represents the abstract base class from which all implementations of the Digital Signature Algorithm (DSA) must inherit.

public ref class DSA abstract : System::Security::Cryptography::AsymmetricAlgorithm
[System.Runtime.InteropServices.ComVisible(true)]
public abstract class DSA : System.Security.Cryptography.AsymmetricAlgorithm
type DSA = class
    inherit AsymmetricAlgorithm
Public MustInherit Class DSA
Inherits AsymmetricAlgorithm
Inheritance
Derived
Attributes

Remarks

You can use the DSA class and derived classes to create digital signatures that help protect the integrity of your data. The DSACryptoServiceProvider provides an implementation of this class.

To use a public-key system to digitally sign a message, the sender first applies a hash function to the message to create a message digest. The sender then encrypts the message digest with the sender's private key to create the sender's personal signature. Upon receiving the message and signature, the receiver decrypts the signature using the sender's public key to recover the message digest and hashes the message using the same hash algorithm that the sender used. If the message digest that the receiver computes exactly matches the message digest received from the sender, the receiver can assume that the message was not altered while in transit. Note that a signature can be verified by anyone, because the sender's public key is common knowledge.

Important

Newer asymmetric algorithms are available. Consider using the RSA class or the ECDsa class instead of the DSA class. Use DSA only for compatibility with legacy applications and data.

Two different versions of the DSA algorithm exist. The original form, described in FIPS 186-2, requires the use of SHA-1 as the hash algorithm and supports key lengths from 512 bits to 1024 bits in increments of 64 bits. An updated version of the algorithm was described in FIPS 186-3, which enabled the use of the SHA-2 family of hash algorithms and added support for 2048 bit keys and 3072 bit keys. Not all derived implementations of this type support the FIPS 186-3 enhancements to DSA. Support can be detected via the LegalKeySizes property.

Constructors

DSA()

Initializes a new instance of the DSA class.

Fields

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

KeyExchangeAlgorithm

When overridden in a derived class, gets the name of the key exchange algorithm. Otherwise, throws an NotImplementedException.

(Inherited from AsymmetricAlgorithm)
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

When implemented in a derived class, gets the name of the signature algorithm. Otherwise, always throws a NotImplementedException.

(Inherited from AsymmetricAlgorithm)

Methods

Clear()

Releases all resources used by the AsymmetricAlgorithm class.

(Inherited from AsymmetricAlgorithm)
Create()

Creates the default cryptographic object used to perform the asymmetric algorithm.

Create(DSAParameters)

Creates a new ephemeral DSA key with the specified DSA key parameters.

Create(Int32)

Creates a new ephemeral DSA key with the specified key size.

Create(String)

Creates the specified cryptographic object used to perform the asymmetric algorithm.

CreateSignature(Byte[])

When overridden in a derived class, creates the DSA signature for the specified hash value.

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)
ExportEncryptedPkcs8PrivateKey(ReadOnlySpan<Byte>, PbeParameters)

Exports the current key in the PKCS#8 EncryptedPrivateKeyInfo format with a byte-based password.

(Inherited from AsymmetricAlgorithm)
ExportEncryptedPkcs8PrivateKey(ReadOnlySpan<Char>, PbeParameters)

Exports the current key in the PKCS#8 EncryptedPrivateKeyInfo format with a char-based password.

(Inherited from AsymmetricAlgorithm)
ExportParameters(Boolean)

When overridden in a derived class, exports the DSAParameters.

ExportPkcs8PrivateKey()

Exports the current key in the PKCS#8 PrivateKeyInfo format.

(Inherited from AsymmetricAlgorithm)
ExportSubjectPublicKeyInfo()

Exports the public-key portion of the current key in the X.509 SubjectPublicKeyInfo format.

(Inherited from AsymmetricAlgorithm)
FromXmlString(String)

Reconstructs a DSA object from an XML string.

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 a specified portion of a byte array by using a specified hashing algorithm.

HashData(Stream, HashAlgorithmName)

When overridden in a derived class, computes the hash value of a specified binary stream by using a specified hashing algorithm.

ImportEncryptedPkcs8PrivateKey(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, Int32)

Imports the public/private keypair from a PKCS#8 EncryptedPrivateKeyInfo structure after decrypting with a byte-based password, replacing the keys for this object.

ImportEncryptedPkcs8PrivateKey(ReadOnlySpan<Char>, ReadOnlySpan<Byte>, Int32)

Imports the public/private keypair from a PKCS#8 EncryptedPrivateKeyInfo structure after decrypting with a char-based password, replacing the keys for this object.

ImportParameters(DSAParameters)

When overridden in a derived class, imports the specified DSAParameters.

ImportPkcs8PrivateKey(ReadOnlySpan<Byte>, Int32)

Imports the public/private keypair from a PKCS#8 PrivateKeyInfo structure after decryption, replacing the keys for this object.

ImportSubjectPublicKeyInfo(ReadOnlySpan<Byte>, Int32)

Imports the public key from an X.509 SubjectPublicKeyInfo structure after decryption, replacing the keys for this object.

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.

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.

SignData(Stream, HashAlgorithmName)

Computes the hash value of the specified stream using the specified hash algorithm and signs the resulting hash value.

ToString()

Returns a string that represents the current object.

(Inherited from Object)
ToXmlString(Boolean)

Creates and returns an XML string representation of the current DSA object.

TryCreateSignature(ReadOnlySpan<Byte>, Span<Byte>, Int32)

Attempts to create the DSA signature for the specified hash into the provided buffer.

TryExportEncryptedPkcs8PrivateKey(ReadOnlySpan<Byte>, PbeParameters, Span<Byte>, Int32)

Attempts to export the current key in the PKCS#8 EncryptedPrivateKeyInfo format into a provided buffer, using a byte-based password.

TryExportEncryptedPkcs8PrivateKey(ReadOnlySpan<Char>, PbeParameters, Span<Byte>, Int32)

Attempts to export the current key in the PKCS#8 EncryptedPrivateKeyInfo format into a provided buffer, using a char-based password.

TryExportPkcs8PrivateKey(Span<Byte>, Int32)

Attempts to export the current key in the PKCS#8 PrivateKeyInfo format into a provided buffer.

TryExportSubjectPublicKeyInfo(Span<Byte>, Int32)

Attempts to export the current key in the X.509 SubjectPublicKeyInfo format into a provided buffer.

TryHashData(ReadOnlySpan<Byte>, Span<Byte>, HashAlgorithmName, Int32)

Attempts to compute the hash value of the provided data into a provided buffer.

TrySignData(ReadOnlySpan<Byte>, Span<Byte>, HashAlgorithmName, Int32)

Attempts to create the DSA signature for the specified data into the provided buffer.

VerifyData(Byte[], Byte[], HashAlgorithmName)

Verifies that a digital signature is valid by calculating the hash value of the specified data using the specified hash algorithm and comparing it to the provided signature.

VerifyData(Byte[], Int32, Int32, Byte[], HashAlgorithmName)

Verifies that a digital signature is valid by calculating the hash value of the data in a portion of a byte array using the specified hash algorithm and comparing it to the provided signature.

VerifyData(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, HashAlgorithmName)

Verifies that a digital signature is valid by calculating the hash value of the data in a byte span using the specified hash algorithm and comparing it to the provided signature.

VerifyData(Stream, Byte[], HashAlgorithmName)

Verifies that a digital signature is valid by calculating the hash value of the specified stream using the specified hash algorithm and comparing it to the provided signature.

VerifySignature(Byte[], Byte[])

When overridden in a derived class, verifies the DSA signature for the specified data.

VerifySignature(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>)

Verifies that a digital signature is valid for a provided data hash.

Explicit Interface Implementations

IDisposable.Dispose()

For a description of this member, see Dispose().

(Inherited from AsymmetricAlgorithm)

Applies to

See also