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Acrobat 9 Family of Products Controlling Signing with Seed Values
Security Feature User Guide Specifying Alternate Signature Handlers and Formats 78
User interface impact : Specifying a non-default handler can result in a different user interface and
workflow during signing.
Seed values for specifying handlers and signature types are the following:

filter :
filter
is the internal name of a signature handler. Signature handlers perform a number of
functions including signature validation. While Acrobat ships with a default handler (Adobe.PPKLite),
custom or third-party handlers such as those from Entrust and VeriSign may be used. The Acrobat SDK
describes how to write a custom handler (Adbe.DocSign).
Tip:
filter
is often used in conjunction with
version
when a minimum filter version is
required.

subfilter :
subfilter
is the internal name of the signature format, such as adbe.pkcs7.detached
intended to be verifiable by signature handlers other than the one that created it. Signature handlers
need to be able to understand the signature type (or format).
Tip: Since it is possible that different handlers might be used for signing and validating,
filter
and
subfilter
are used together to assure that signing workflows with
different components are interoperable. These properties are identical to those in the
signature dictionary. For more information, refer to the
PDF Reference .
To specify a signature handlers and format type:
1. Create a signature field with an intuitive name and tooltip.
2. Create the JavaScript that gets the field object and uses the seed value method ( Example 5.6 ).
3. Specify a
filter
.
4. If
filter
is specified, you may use the optional
version
as follows:

PPKLite for Acrobat 6.X: 0

PPKLite for Acrobat 7.x: 1

Custom handlers: Any.
5. Enter the handler name and
subfilter
type. Third parties may define their own subfilters but should
follow the naming convention recommended in the PDF Reference . The PDF Reference defines the
following standard
subfilter
values:

adbe.x509.rsa_sha1

adbe.pkcs7.detached

adbe.pkcs7.sha1
6. Run the JavaScript, save the document, and test the field.
Example 5.6 Seed value: Specifying signature components
// Obtain the signature field object:
var f = this.getField("mySigFieldName");
f.signatureSetSeedValue(
{
filter: "Entrust.PPKEF",
subfilter: “adbe.x509.rsa_sha1
} )