The SignerInfo.Certificate property retrieves the signing certificate associated with the signer information.

The SignerInfo.CounterSignerInfos property retrieves the set of counter signers associated with the signer information.

The SignerInfo.DigestAlgorithm property retrieves the System.Security.Cryptography.Oid object that represents the hash algorithm used in the computation of the signatures.

The SignerInfo.SignedAttributes property retrieves the System.Security.Cryptography.CryptographicAttributeObjectCollection collection of signed attributes that is associated with the signer information. Signed attributes are signed along with the rest of the message content.

The SignerInfo.SignerIdentifier property retrieves the certificate identifier of the signer associated with the signer information.

The SignerInfo.UnsignedAttributes property retrieves the System.Security.Cryptography.CryptographicAttributeObjectCollection collection of unsigned attributes that is associated with the System.Security.Cryptography.Pkcs.SignerInfo content. Unsigned attributes can be modified without invalidating the signature.

The SignerInfo.Version property retrieves the signer information version.

The SignerInfo.CheckHash method verifies the data integrity of the CMS/PKCS #7 message signer information. SignerInfo.CheckHash is a specialized method used in specific security infrastructure applications in which the subject uses the HashOnly member of the System.Security.Cryptography.Pkcs.SubjectIdentifierType enumeration when setting up a System.Security.Cryptography.Pkcs.CmsSigner object. SignerInfo.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 SignerInfo.CheckSignature(bool) or SignerInfo.CheckSignature(System.Security.Cryptography.X509Certificates.X509Certificate2Collection, bool) methods.

The SignerInfo.CheckSignature(bool) method verifies the digital signature of the message and, optionally, validates the certificate.

The SignerInfo.CheckSignature(System.Security.Cryptography.X509Certificates.X509Certificate2Collection, bool) method verifies the digital signature of the message by using the specified collection of certificates and, optionally, validates the certificate.

The SignerInfo.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.

The SignerInfo.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.

The SignerInfo.RemoveCounterSignature(int) method removes the countersignature at the specified index of the SignerInfo.CounterSignerInfos collection.

The SignerInfo.RemoveCounterSignature(SignerInfo) method removes the countersignature for the specified System.Security.Cryptography.Pkcs.SignerInfo object.