Signifies the start of signature validation.
func onSignatureFound(issuerRDN: String, serialNumber: Data, subjectKeyID: Data, certFound: Bool, validateSignature: inout Bool, validateChain: inout Bool)
This event tells the application that signature validation is about to start, and provides the details about the signer's certificate via its IssuerRDN, SerialNumber, and SubjectKeyID parameters. It fires for every signature located in the verified document or message.
The CertFound is set to True if the class has found the needed certificate in one of the known locations, and to False otherwise, in which case you must provide it manually via KnownCertificates property.
Signature validation consists of two independent stages: cryptographic signature validation and chain validation. Separate validation results are reported for each, with SignatureValidationResult and ChainValidationResult properties respectively.
Use the ValidateSignature and ValidateChain parameters to tell the verifier which stages to include in the validation.