SetSignatureFieldSeedValue

Security and signatures

Description

Creates or replaces the /SV seed-value dictionary of an unsigned signature field and selects which constraints a signing operation must enforce

Syntax

Delphi

Function TPDFlib.SetSignatureFieldSeedValue(Index, Flags: Integer; Const SubFilters, DigestMethods, Reasons: WideString; Const LegalAttestations: WideString= ''): Integer;

ActiveX

Function PDFlib::SetSignatureFieldSeedValue(Index As Long, Flags As Long, SubFilters As String, DigestMethods As String, Reasons As String) As Long

DLL

int DLSetSignatureFieldSeedValue(int InstanceID, int Index, int Flags, const wchar_t* SubFilters, const wchar_t* DigestMethods, const wchar_t* Reasons);

Parameters

Index	One-based form-field index identifying an unsigned signature field
Flags	Bit mask selecting required constraints: `PDF_SIGNATURE_SEED_FILTER` (1) filter, `PDF_SIGNATURE_SEED_SUBFILTER` (2) SubFilter, `PDF_SIGNATURE_SEED_VERSION` (4) seed-value version, `PDF_SIGNATURE_SEED_REASON` (8) reason, `PDF_SIGNATURE_SEED_LEGAL_ATTESTATION` (16) legal attestation, `PDF_SIGNATURE_SEED_ADD_REV_INFO` (32) revocation information, and `PDF_SIGNATURE_SEED_DIGEST_METHOD` (64) digest method
SubFilters	Semicolon-delimited allowed SubFilter names such as `ETSI.CAdES.detached` or `adbe.pkcs7.detached`
DigestMethods	Semicolon-delimited allowed digest names: `SHA1`, `SHA256`, `SHA384`, `SHA512`, `SHA3-256`, `SHA3-384`, or `SHA3-512`
Reasons	Semicolon-delimited allowed signing reasons; an empty list or `.` prohibits a custom reason when the reason flag is required
LegalAttestations	Semicolon-delimited allowed legal attestation names for the `/LegalAttestation` seed-value constraint; empty by default. Delphi API extension not exposed through the DLL or ActiveX layers

Return values

1	The seed-value dictionary was written
0	The field, flags, or a required value list was invalid

Remarks

The method writes seed-value version 2 and filter Adobe.PPKLite

Required constraints that this release cannot enforce are rejected when the dictionary is authored and fail closed when read from an existing PDF

The ANSI DLL variant is DLSetSignatureFieldSeedValueA