SQL Server Requires Chilkat v11.7.0+

Replace Text in a Signed PDF (PreserveSignatures)

See more PDF Text Replacement Examples

Applying a text replacement rewrites the page content, which invalidates any digital signature on the PDF. While the PreserveSignatures property is true (the default), "apply" is refused on a signed PDF; "check" only reads and is always allowed. Setting PreserveSignatures to false allows the replacement; the signature field stays in the written PDF but no longer verifies, so the document should be signed again afterwards if a signature is wanted. SQL Server

--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    DECLARE @iTmp0 int
    DECLARE @sTmp0 nvarchar(4000)
    DECLARE @success int
    SELECT @success = 0

    --  This example requires the Chilkat API to have been previously unlocked.
    --  See Global Unlock Sample for sample code.

    --  The PDF used in this example is available at invoice_signed.pdf

    DECLARE @pdf int
    EXEC @hr = sp_OACreate 'Chilkat.Pdf', @pdf OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    EXEC sp_OAMethod @pdf, 'LoadFile', @success OUT, 'qa_data/pdf/invoice_signed.pdf'
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @pdf, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @pdf
        RETURN
      END

    EXEC sp_OAGetProperty @pdf, 'NumSignatures', @iTmp0 OUT
    PRINT 'Signatures: ' + @iTmp0

    DECLARE @json int
    EXEC @hr = sp_OACreate 'Chilkat.JsonObject', @json OUT

    EXEC sp_OAMethod @json, 'UpdateString', @success OUT, 'labels[0].label', 'Invoice Number:'
    EXEC sp_OAMethod @json, 'UpdateString', @success OUT, 'labels[0].value', 'INV-2026-0500'

    --  "check" reads only, so it works on a signed PDF.
    DECLARE @jsonOut int
    EXEC @hr = sp_OACreate 'Chilkat.JsonObject', @jsonOut OUT

    EXEC sp_OAMethod @pdf, 'TextReplace', @success OUT, 'check', @json, @jsonOut
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @pdf, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @pdf
        EXEC @hr = sp_OADestroy @json
        EXEC @hr = sp_OADestroy @jsonOut
        RETURN
      END

    EXEC sp_OAMethod @jsonOut, 'BoolOf', @iTmp0 OUT, 'ok'
    PRINT 'check: ok = ' + @iTmp0

    --  "apply" is refused while PreserveSignatures is true (the default).
    EXEC sp_OAMethod @pdf, 'TextReplace', @success OUT, 'apply', @json, @jsonOut
    IF @success = 0
      BEGIN

        EXEC sp_OAGetProperty @pdf, 'LastErrorText', @sTmp0 OUT
        PRINT 'apply refused: ' + @sTmp0
      END

    --  Allowing the signature to be broken:
    EXEC sp_OASetProperty @pdf, 'PreserveSignatures', 0
    EXEC sp_OAMethod @pdf, 'TextReplace', @success OUT, 'apply', @json, @jsonOut
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @pdf, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @pdf
        EXEC @hr = sp_OADestroy @json
        EXEC @hr = sp_OADestroy @jsonOut
        RETURN
      END

    EXEC sp_OAMethod @jsonOut, 'BoolOf', @iTmp0 OUT, 'applied'
    PRINT 'applied: ' + @iTmp0

    --  The written PDF is a full rewrite with the replacement.  The signature field is still in the document,
    --  but the bytes it signed are gone, so it no longer verifies.
    EXEC sp_OAMethod @pdf, 'WriteFile', @success OUT, 'qa_output/invoice_reissued_broken_signature.pdf'
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @pdf, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @pdf
        EXEC @hr = sp_OADestroy @json
        EXEC @hr = sp_OADestroy @jsonOut
        RETURN
      END

    EXEC sp_OAGetProperty @pdf, 'NumSignatures', @iTmp0 OUT
    PRINT 'Signatures after writing: ' + @iTmp0
    DECLARE @sigInfo int
    EXEC @hr = sp_OACreate 'Chilkat.JsonObject', @sigInfo OUT

    DECLARE @validated int
    EXEC sp_OAMethod @pdf, 'VerifySignature', @validated OUT, 0, @sigInfo

    PRINT 'Signature 0 verifies: ' + @validated

    --  Sample output:

    --  Signatures: 1
    --  check: ok = true
    --  apply refused: ChilkatLog:
    --    TextReplace:
    --      DllDate: Nov  7 2026
    --      ChilkatVersion: 11.7.0
    --      UnlockPrefix: CHLKAT
    --      UnlockStatus: 2
    --      Architecture: Little Endian; 64-bit
    --      Language: Visual C++ 11.0 / x64
    --      VerboseLogging: 0
    --      replaceTextOp:
    --        op: apply
    --        The PDF is signed: replacing text rewrites the content and invalidates the signatures (set PreserveSignatures = false to allow it).
    --      --replaceTextOp
    --      Failed.
    --    --TextReplace
    --  --ChilkatLog
    --  
    --  applied: true
    --  Signatures after writing: 1
    --  Signature 0 verifies: false

    EXEC @hr = sp_OADestroy @pdf
    EXEC @hr = sp_OADestroy @json
    EXEC @hr = sp_OADestroy @jsonOut
    EXEC @hr = sp_OADestroy @sigInfo


END
GO