TPDFlibSignatureVerifier

Security and Signatures

Description

Enumerates PDF signature fields and CMS signers, validates a selected signature without loading the complete PDF into memory, and reports the selected signature's own incremental revision separately from the current file

The verifier accepts a file, caller-owned stream, or ANSI byte string through OpenPDF, OpenPDFStream, or OpenPDFString

Selection

Count := Verifier.GetSignatureCount;
Verifier.GetSignatureFieldName(0, FieldName);
SignerCount := Verifier.GetSignerCount(0);
Result := Verifier.VerifySignatureByName(FieldName, 0, Report);

VerifySignatureByIndex selects a PDF field by zero-based index, while VerifySignatureByName uses the fully qualified AcroForm field name and both methods accept a zero-based CMS signer index

Signature verification report

IntegrityResult	Cryptographic CMS or legacy PKCS#7 integrity result for the selected signer
CoverageStatus	`scInvalid`, `scSignedRevision`, or `scWholeDocument`
ByteRangeValid	True only when all ranges are bounded and the signed revision ends at its own `%%EOF`
ContentsGapValid	True only when the omitted bytes are exactly the selected hexadecimal `/Contents` token
HasLaterRevisions	True when the selected signature authenticates an earlier incremental revision and later bytes exist
SignedRevisionLength	Byte length of the revision authenticated by the selected signature
PermissionReport	Parsed DocMDP and FieldMDP constraints for the selected signature

Certification and field permissions

GetSignaturePermissionInfo and GetSignaturePermissionInfoByName return TPDFlibSignaturePermissionReport

The report distinguishes a valid DocMDP transform from a matching catalog /Perms /DocMDP reference and verifies that a field /Lock dictionary matches its FieldMDP transform, action, and field-name list

Certificate chain and revocation

VerifySignerCertificateChainEx and VerifySignerCertificateChainExByName accept srmNone, srmCacheOnly, or srmOnline, plus an optional verification time

TPDFlibSignatureChainReport separates TrustStatus, Windows chain and policy errors, DSS or VRI evidence counts, exact OCSP attribution, OCSP status, revocation reason, freshness, and native errors

Embedded certificates and validation material can complete a chain but do not convert an untrusted root into a trusted root

DSS or VRI OCSP evidence is accepted only when its responder signature, issuer or delegated responder usage, CertID, status, and freshness match the selected certificate

RFC 3161 timestamps

VerifyDocumentTimeStamp* validates a document timestamp against the signature ByteRange data

GetSignatureTimeStampCount and VerifySignatureTimeStamp* enumerate and validate id-aa-signatureTimeStampToken attributes against the selected CMS signer signatureValue

The Ex variants also accept revocation mode, expected policy OID, and expected nonce

TPDFlibTimeStampVerificationReport reports token-signature validity, message-imprint validity, TSA EKU and name binding, policy, nonce, generation time, chain result, and trust status independently

Compatibility methods

VerifySignature, GetSignatureMetadata, GetSignerCertificate, and VerifySignerCertificateChain remain available and select field 0 and signer 0

The corresponding ByIndex and ByName methods provide explicit selection for multi-signature and multi-signer documents