Represents a digital signature field in a document.

As well as providing authorization, digital signatures can also be used to detect whether a file has been altered since signing took place.



Method Description
Throws Exceptions AddLTV Add Long Term Validation (LTV) to the Document Security Store (DSS).
Throws Exceptions Certify Make this a certification signature.
Throws Exceptions Commit Commit a previously signed signature to the document.
GetCertificates Extract the encoded X.509 data of the certificate(s).
LockFields Lock document fields to stop them being modified.
Throws Exceptions Sign Sign the digital signature using a private key and password.
Throws Exceptions Timestamp Sign a document timestamp signature field using a Timestamping Authority (TSA).
Throws Exceptions Validate Check and validate the status of this signature.


Property Description
Algorithm The type of hash algorithm used in the signature.
IsCertification Whether this a certification signature rather than an approval signature.
IsModified True if the PDF has been tampered with after signing.
IsSecure True if the signature and document look well formed and well applied.
IsTrusted True if the signature's certificate is trusted according to the validation policy.
CompliancePades The signature compliance level.
CustomSigner A delegate called to perform custom signing of the PDF.
IsTimeValid True if the signature's certificate was time-valid when the document was signed.
Location The location of the signing.
Reason The reason for signing.
Signer The name of the person signing.
SigningRevision The revision at which the signature was signed.
Throws Exceptions SigningUtcTime The time of signing in UTC format.
TimestampHashAlgorithm The hash algorithm used to create the digest for timestamp requests.
TimestampServiceUrl The URL to a time-stamping service.
ValidationPolicy The validation policy for certificates.
Validity The validity of the signature.