iText.Signatures.SignatureUtil Class Reference

Utility class that provides several convenience methods concerning digital signatures. More...

Public Member Functions
	SignatureUtil (PdfDocument document)
	Creates a SignatureUtil instance. More...
virtual PdfPKCS7	ReadSignatureData (String signatureFieldName)
	Prepares an PdfPKCS7 instance for the given signature. More...
virtual PdfSignature	GetSignature (String name)
	Get PdfSignature dictionary based on the provided name. More...
virtual PdfDictionary	GetSignatureDictionary (String name)
	Gets the signature dictionary, the one keyed by /V. More...
virtual PdfDictionary	GetSignatureFormFieldDictionary (String name)
virtual IList< String >	GetSignatureNames ()
	Gets the field names that have signatures and are signed. More...
virtual IList< String >	GetBlankSignatureNames ()
	Gets the field names that have blank signatures. More...
virtual int	GetTotalRevisions ()
	Get the amount of signed document revisions. More...
virtual int	GetRevision (String field)
	Get signed document revision number, which corresponds to the provided signature name. More...
virtual String	GetTranslatedFieldName (String name)
	Get field name, translated using XFA, if any present in the document. More...
virtual Stream	ExtractRevision (String field)
	Extracts a revision from the document. More...
virtual bool	SignatureCoversWholeDocument (String name)
	Checks if the signature covers the entire document (except for signature's Contents) or just a part of it. More...
virtual bool	DoesSignatureFieldExist (String name)
	Checks whether a name exists as a signature field or not. More...

Detailed Description

Utility class that provides several convenience methods concerning digital signatures.

Constructor & Destructor Documentation

SignatureUtil()

iText.Signatures.SignatureUtil.SignatureUtil ( PdfDocument  document )

inline

Creates a SignatureUtil instance.

Creates a SignatureUtil instance. Sets the acroForm field to the acroForm in the PdfDocument. iText will create a new AcroForm if the PdfDocument doesn't contain one.

Parameters

document

PdfDocument to be inspected

Member Function Documentation

DoesSignatureFieldExist()

virtual bool iText.Signatures.SignatureUtil.DoesSignatureFieldExist ( String  name )

inlinevirtual

Checks whether a name exists as a signature field or not.

Checks whether a name exists as a signature field or not. It checks both signed fields and blank signatures.

Parameters

name	name of the field

Returns

boolean does the signature field exist

ExtractRevision()

virtual Stream iText.Signatures.SignatureUtil.ExtractRevision ( String  field )

inlinevirtual

Extracts a revision from the document.

Parameters

field

the signature field name

Returns

an InputStream covering the revision. Returns null if it's not a signature field

GetBlankSignatureNames()

virtual IList iText.Signatures.SignatureUtil.GetBlankSignatureNames ( )

inlinevirtual

Gets the field names that have blank signatures.

Returns

List containing the field names that have blank signatures

GetRevision()

virtual int iText.Signatures.SignatureUtil.GetRevision ( String  field )

inlinevirtual

Get signed document revision number, which corresponds to the provided signature name.

Parameters

field

signature name

Returns

int revision number

GetSignature()

virtual PdfSignature iText.Signatures.SignatureUtil.GetSignature ( String  name )

inlinevirtual

Get PdfSignature dictionary based on the provided name.

Parameters

name	signature name

Returns

PdfSignature instance corresponding to the provided name. null otherwise

GetSignatureDictionary()

virtual PdfDictionary iText.Signatures.SignatureUtil.GetSignatureDictionary ( String  name )

inlinevirtual

Gets the signature dictionary, the one keyed by /V.

Parameters

name	the field name

Returns

the signature dictionary keyed by /V or null if the field is not a signature

GetSignatureNames()

virtual IList iText.Signatures.SignatureUtil.GetSignatureNames ( )

inlinevirtual

Gets the field names that have signatures and are signed.

Returns

List containing the field names that have signatures and are signed

GetTotalRevisions()

virtual int iText.Signatures.SignatureUtil.GetTotalRevisions ( )

inlinevirtual

Get the amount of signed document revisions.

Returns

int amount of signed document revisions

GetTranslatedFieldName()

virtual String iText.Signatures.SignatureUtil.GetTranslatedFieldName ( String  name )

inlinevirtual

Get field name, translated using XFA, if any present in the document.

Parameters

name	field name to be translated

Returns

translated field name if XFA is present, original name otherwise

ReadSignatureData()

virtual PdfPKCS7 iText.Signatures.SignatureUtil.ReadSignatureData ( String  signatureFieldName )

inlinevirtual

Prepares an PdfPKCS7 instance for the given signature.

Prepares an PdfPKCS7 instance for the given signature. This method handles signature parsing and might throw an exception if signature is malformed.

The returned PdfPKCS7 can be used to fetch additional info about the signature and also to perform integrity check of data signed by the given signature field.

Prepared PdfPKCS7 instance calculates digest based on signature's /ByteRange entry. In order to check that /ByteRange is properly defined and given signature indeed covers the current PDF document revision please use SignatureCoversWholeDocument(System.String) method.

Parameters

signatureFieldName

the signature field name

Returns

a PdfPKCS7 instance which can be used to fetch additional info about the signature and also to perform integrity check of data signed by the given signature field.

SignatureCoversWholeDocument()

virtual bool iText.Signatures.SignatureUtil.SignatureCoversWholeDocument ( String  name )

inlinevirtual

Checks if the signature covers the entire document (except for signature's Contents) or just a part of it.

Checks if the signature covers the entire document (except for signature's Contents) or just a part of it.

If this method does not return true it means that signature in question does not cover the entire contents of current iText.Kernel.Pdf.PdfDocument . Such signatures cannot be considered as verifying the PDF document, because content that is not covered by signature might have been modified since the signature creation.

Parameters

name	the signature field name

Returns

true if the signature covers the entire document, false if it doesn't