SignerInfo Class

.NET Framework (current version)

Other Versions

The SignerInfo class represents a signer associated with a SignedCms object that represents a CMS/PKCS #7 message.

Namespace: System.Security.Cryptography.Pkcs
Assembly: System.Security (in System.Security.dll)

Inheritance Hierarchy

System::Object
System.Security.Cryptography.Pkcs::SignerInfo

Syntax

C++

[HostProtectionAttribute(SecurityAction::LinkDemand, MayLeakOnAbort = true)]
public ref class SignerInfo sealed

Properties

	Name	Description
	Certificate	The Certificate property retrieves the signing certificate associated with the signer information.
	CounterSignerInfos	The CounterSignerInfos property retrieves the set of counter signers associated with the signer information.
	DigestAlgorithm	The DigestAlgorithm property retrieves the Oid object that represents the hash algorithm used in the computation of the signatures.
	SignedAttributes	The SignedAttributes property retrieves the CryptographicAttributeObjectCollection collection of signed attributes that is associated with the signer information. Signed attributes are signed along with the rest of the message content.
	SignerIdentifier	The SignerIdentifier property retrieves the certificate identifier of the signer associated with the signer information.
	UnsignedAttributes	The UnsignedAttributes property retrieves the CryptographicAttributeObjectCollection collection of unsigned attributes that is associated with the SignerInfo content. Unsigned attributes can be modified without invalidating the signature.
	Version	The Version property retrieves the signer information version.

Methods

	Name	Description
	CheckHash()	The CheckHash method verifies the data integrity of the CMS/PKCS #7 message signer information. CheckHash is a specialized method used in specific security infrastructure applications in which the subject uses the HashOnly member of the SubjectIdentifierType enumeration when setting up a CmsSigner object. CheckHash does not authenticate the signer information because this method does not involve verifying a digital signature. For general-purpose checking of the integrity and authenticity of CMS/PKCS #7 message signer information and countersignatures, use the CheckSignature(Boolean) or CheckSignature(X509Certificate2Collection^, Boolean) methods.
	CheckSignature(Boolean)	The CheckSignature(Boolean) method verifies the digital signature of the message and, optionally, validates the certificate.
	CheckSignature(X509Certificate2Collection^, Boolean)	The CheckSignature(X509Certificate2Collection^, Boolean) method verifies the digital signature of the message by using the specified collection of certificates and, optionally, validates the certificate.
	ComputeCounterSignature()	The ComputeCounterSignature() method prompts the user to select a signing certificate, creates a countersignature, and adds the signature to the CMS/PKCS #7 message. Countersignatures are restricted to one level.
	ComputeCounterSignature(CmsSigner^)	The ComputeCounterSignature(CmsSigner^) method creates a countersignature by using the specified signer and adds the signature to the CMS/PKCS #7 message. Countersignatures are restricted to one level.
	Equals(Object^)	Determines whether the specified object is equal to the current object.(Inherited from Object.)
	GetHashCode()	Serves as the default hash function. (Inherited from Object.)
	GetType()	Gets the Type of the current instance.(Inherited from Object.)
	RemoveCounterSignature(Int32)	The RemoveCounterSignature method removes the countersignature at the specified index of the CounterSignerInfos collection.
	RemoveCounterSignature(SignerInfo^)	The RemoveCounterSignature method removes the countersignature for the specified SignerInfo object.
	ToString()	Returns a string that represents the current object.(Inherited from Object.)

Remarks

The signatures represented by the SignerInfo class can be either over message content or a signature. The latter kind of signature is referred to as a countersignature.

This implementation of CMS/PKCS #7 supports only one level of countersignature. That is, a signature can be signed, which forms a countersignature, but that countersignature cannot be signed again.

This class does not have a public constructor; therefore, it cannot be publicly instantiated. It is a read-only class accessible from the SignedCms::SignerInfos property.

Version Information

.NET Framework
Available since 2.0

Thread Safety

Any public static ( Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.