THotPDF.SaveIncrementalUpdateAuthenticated Method

Authenticates signed revision policies, rejects prohibited changes, and atomically publishes an incremental update

Declarations

function SaveIncrementalUpdateAuthenticated(
  const TargetFile: TFileName;
  const Options: THPDFAuthenticatedIncrementalUpdateOptions;
  out Info: THPDFAuthenticatedIncrementalUpdateInfo
): Boolean; overload;

function SaveIncrementalUpdateAuthenticated(
  const TargetFile: TFileName;
  out Info: THPDFAuthenticatedIncrementalUpdateInfo
): Boolean; overload;

Workflow

Writes the pending incremental revision to a unique candidate in the target directory
Loads every policy from the exact revision protected by its signature byte range
Authenticates each policy-bearing CMS signature and optionally validates its certificate path
Classifies every later revision and enforces DocMDP, FieldMDP, UR or UR3, Identity, and unknown-transform decisions
Publishes the accepted candidate with a write-through atomic replacement

A rejection deletes the candidate and leaves an existing target byte-for-byte unchanged

Options

Member	Purpose
`Authentication`	`ipaCryptographic` requires a valid CMS byte-range signature, while `ipaTrustedCertificate` additionally requires `cvsTrusted` from certificate path and revocation validation
`RequireSignaturePolicy`	Rejects documents without an authenticated transform policy when `True`, which is the default
`CertificateValidation`	Trust anchors, intermediates, offline revocation evidence, validation time, purpose, and algorithm policy used by trusted-certificate mode

Result details

THPDFAuthenticatedIncrementalUpdateInfo reports the final status, failing signature index, signature and certificate status, total signature count, authenticated policy count, and a diagnostic issue

Important statuses include aiusAccepted, aiusNoSignaturePolicy, aiusSignatureInvalid, aiusCertificateUntrusted, aiusPolicyMalformed, aiusPolicyViolation, and aiusCommitFailed

Usage

var
  Info: THPDFAuthenticatedIncrementalUpdateInfo;
begin
  PDF.BeginIncrementalUpdate('certified.pdf');
  PDF.SetLoadedFormFieldValueByName('CustomerName', 'Ada');
  if not PDF.SaveIncrementalUpdateAuthenticated('updated.pdf', Info) then
    raise Exception.Create(String(Info.Issue));
end;

Security boundary

A structurally present policy never becomes authoritative until its signature authenticates successfully
Policy dictionaries are read from the signed snapshot and bound to the original signature object, byte range, and CMS value, preventing a later revision from redirecting or replacing its own authority
Trusted-certificate mode is appropriate when signer identity matters in addition to document integrity
The ordinary SaveIncrementalUpdate method remains available for unsigned workflows that do not request policy enforcement