PdfDigitalSignatureSignerCertificates Property

Gets the certificate chain embedded in the signature, as DER encoded X.509 certificates ordered from the signer certificate to the highest known certificate authority: the chain stored in the PFX certificate, the chain given to the PdfDigitalSignature(IExternalDigitalSignature, Byte) constructor or, for a Certificate, the chain found in the certificate stores of the system and in TrustedCaCertificates

public byte[][] SignerCertificates { get; }