How Can You Create A Signature Field For A Pdf Template?

I have been searching through itextsharp classes: http://api.itextpdf.com/itext/ And I found that you can create buttons, checkboxes, radio buttons, textboxes: But I do not unders

Solution 1:

Please read http://itextpdf.com/book/digitalsignatures and more specifically section 2.3.2 entitled "Creating a signature field programmatically using iText".

However, you also need to read section 2.4.4, entitled "Ordinary and Certifying signatures":

ISO-32000-1 specifies that a PDF document may contain the following standard types of signatures:

• One or more approval signatures— ...
• At most one certification signature— ...
• At most two usage rights signatures— these are signatures created using a private key that is proprietary for instance to Adobe. When a PDF document is signed with a usage rights signature using Adobe’s key, the document is Reader enabled. Adobe Reader will unlock certain usage rights, for instance allowing you to save a filled out form locally. Other vendors can use their private key to enforce similar usage rights. This type of signature is outside the scope of this paper.

If you want to create a document that can be signed by end users without the requirement of any other software than Adobe Reader, your document needs to be 'Reader enabled'. Because of the reason explained in the white paper on digital signing, you need Adobe software to do this. It would be illegal for any third party different from Adobe to use Adobe's private key.

Extra remark: Note that digital signatures and signature fields involve much more than just allowing an end user to 'sign his name'. He'll always need a private key to sign a document. Suppose that this wasn't what you meant with your question, suppose that you want people to fill out their name in a text field, then you'd still need to Reader-enable the document, unless the end users is using one of the more recent versions of Adobe Reader which unlock the possibility to save a filled out form.

Final remark: Now I see that you need people to 'draw' their signature. That is NOT a valid digital signature, and you CAN NOT provide a field to add such a fake signature. Adding such a fake signature is something that needs to be provided in the viewer that is used by the end user. If you want to know why these signatures are fake and have no legal value whatsoever, please watch this demo: http://www.youtube.com/watch?v=VYK45lhLr8I

Solution 2:

You can create an empty signature field using iText as explained in the sample SignatureField from iText in Action, 2nd edition. The sample should be easily translatable to C# using iTextSharp. Whether you need something like this to sign, depends on the PDF viewer and its version.