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Acrobat 9 Family of Products
Controlling Signing with Seed Values
Security Feature User Guide
Changes Across Releases 68
Seed values should not be set on signed documents and cannot be set on certified documents after
the document is certified. They are primarily used to configure fields on documents that are not yet
signed.
Setting a seed value often causes Acrobat to not display or use its default settings. For example, default
reasons are stored in a registry list, and specifying signing reasons with a seed value overrides that list.
Seed value properties include those listed in
Table 8
. Note that
certspec
and
timeStampspec
are
objects that have multiple properties.
5.1.1 Changes Across Releases
Each Acrobat release results in support for additional seed values as shown in
Table 7
.
Table 7 Seed values: Changes across releases
Seed value
First support for seed value
6
7
8
9
certspec
Specifies that certain certificates must be used for a particular signature field.
6.0-7.x
: Supports subject, issuer, and oid.
8.x
: Adds support for subjectDN, issuerDN, keyUsage, url, and urlType
X
X
X
X
filter
The language-independent name of the security handler to be used when signing.
X
X
X
X
flags
A set of bit flags controlling which properties are required.
6.0-7.x
: 1: filter, 2: subFilter, 4: version, and 8: reasons.
8.0
: 16: legalAttestations, 32: shouldAddRevInfo, and 64: digestMethod.
X
X
X
X
legalAttestations
A list of legal attestations that the user can use when creating an MDP (certification) signature.
X
X
X
X
mdp
Can be used to force a certification signature as well as to control permitted document changes. X
X
X
X
reasons
A list of reasons that the user is allowed to use when signing.
8.0
: Supports disabling signing reasons.
X
X
X
X
subFilter
An array of acceptable signature formats.
X
X
X
X
timeStampspec
Specifies a timestamp server using the
url
and
flags
properties.
X
X
X
X
version
The signature handler version to be used to sign the signature field. Valid values are 1 and 2.
8.0
: Must be set to 2 if this seed value object contains Acrobat 8-specific content marked as
required.
X
X
X
X
digestMethod
The algorithm used to created the message digest.
6.0-7.x
: MD5, SHA1.
8.0
: Adds support for SHA256, SHA384, SHA512, and RIPEMD160.
Note
: SHA256, SHA384, and SHA512 are not supported in Windows CAPI until Acrobat 9.1, and
not supported in Windows at all prior to XP-SP3.
X
X
X
X
shouldAddRevInfo
Controls how the application does certificate and chain revocation checking.
X
X
lockDocument
Allows the author to add a Lock Document checkbox to the signing dialog so a signer can lock
the document at the time of signing.
X
appearanceFilter
A text string naming the appearance required to be used when signing the signature field.
X