PdfTools.Sign Namespace

The visual appearance of signatures

A signature may have a visual appearance on a page of the document. The visual appearance is optional and has no effect on the validity of the signature. Because of this and because a visual appearance may cover important content of the page, it is recommended to create invisible signatures by default.

Typically, a visual appearance is created for forms with a dedicated area reserved for the appearance. Other transaction documents, e.g. invoices, correspondence, or bank statements, are usually signed without a visual appearance.

The appearance can be positioned on a page using PageNumber, Top, Right, Bottom, and Left. It is recommended to set either Top or Bottom and Right or Left. If all are , the default is to position the appearance in the lower right corner with 12 pt (1/6 inch or 4.2 mm) distance to the bottom and right edge of the page, i.e. Bottom = 12 and Right = 12.

The permission options when certifying a document

Additional document level options

These options are available for all signature operations of the Signer. They can also be used without a signature operation with the method Process(Document, Stream, OutputOptions, Provider).

Notes on document encryption when processing files with the Signer:

• PDF/A conformance is removed from input files. In this case, a Warning with an PdfARemoved is generated.
• Signed documents cannot be encrypted or decrypted. In this case, a Warning with an SignedDocEncryptionUnchanged is generated.

A document that has been prepared for signing

Configuration for signature creation

This configuration controls the signature creation in Sign(Document, SignatureConfiguration, Stream, OutputOptions) and Certify(Document, SignatureConfiguration, Stream, MdpPermissionOptions, OutputOptions).

Use a Provider to create a signature configuration.

Note that this object can be re-used to sign multiple documents for mass-signing applications.

Options for adding unsigned signature fields

Process signatures and signature fields

Configuration for adding time-stamps

This configuration controls the creation of time-stamps in AddTimestamp(Document, TimestampConfiguration, Stream, OutputOptions).

Use a Provider to create a time-stamp configuration.

Note that this object can be re-used to add time-stamps to multiple documents for mass-signing applications.

The warning category