Contains a signature and the data necessary to verify the authenticity of a signed form.
It is created by a form viewer or other program when a user signs a form (usually using a signature button). The signature item contains an encrypted hash value that makes it impossible to modify the form without changing the hash value that the modified form would generate. To verify, one can generate the hash value and then see if it matches the one in the signature.
colorinfo, excludedmetadata, fullname, itemnext, itemprevious, layoutinfo, mimedata, signature, signdatagroups, signdetails, signer, signformat, signgroups, signinstances, signitemrefs, signitems, signnamespaces, signoptionrefs, signoptions, signpagerefs
This example shows a signature item under the signature button that created it.
<button sid="empSigButton">
<type>signature</type>
<value compute="signer"></value>
<signer>Jane D Smith, jsmith@insurance.com</signer>
<format>
<datatype>string</datatype>
<constraints>
<mandatory>on</mandatory>
</constraints>
</format>
<signformat>application/vnd.xfdl;
csp="Microsoft Base Cryptographic Provider v1.0";
csptype=rsa_full;hashalg=sha1
</signformat>
<signoptions>
<filter>omit</filter>
<optiontype>triggeritem</optiontype>
<optiontype>coordinates</optiontype>
</signoptions>
<signitemrefs>
<filter>omit</filter>
<itemref>PAGE1.mgrSigButton</itemref>
<itemref>PAGE1.admSigButton</itemref>
<itemref>PAGE1.empsignature</itemref>
<itemref>PAGE1.mgrsignature</itemref>
<itemref>PAGE1.admsignature</itemref>
</signitemrefs>
<signature>empsignature</signature>
</button>
...
<signature sid="empsignature">
<signformat>application/vnd.xfdl;
csp="Microsoft Base Cryptographic Provider v1.0";
csptype=rsa_full;hashalg=sha1
</signformat>
<signer>Jane D Smith, jsmith@insurance.com</signer>
<fullname>
"Verisign, Inc.", Verisign Trust Network,
"www.verisign.com/repository/RPA Incorp. by
Ref.,LIAB.LTD(c)98", Persona Not Validated,
Digital ID Class 1 - Microsoft, Jane D
Smith, jsmith@insurance.com
</fullname>
<signature>PAGE1.empsignature</signature>
<signitemrefs>
<filter>omit</filter>
<itemref>PAGE1.mgrSigButton</itemref>
<itemref>PAGE1.admSigButton</itemref>
<itemref>PAGE1.empsignature</itemref>
<itemref>PAGE1.mgrsignature</itemref>
<itemref>PAGE1.admsignature</itemref>
</signitemrefs>
<!-- The items listed previously MUST have itemlocation options with
absolute and extent as the last settings in order for the filter
to be sufficient in terms of security -->
<signoptionrefs>
<filter>keep</filter>
<optionref>PAGE1.mgrSigButton.itemlocation</optionref>
<optionref>PAGE1.admSigButton.itemlocation</optionref>
<optionref>PAGE1.empsignature.itemlocation</optionref>
<optionref>PAGE1.mgrsignature.itemlocation</optionref>
<optionref>PAGE1.admsignature.itemlocation</optionref>
</signoptionrefs>
<signoptions>
<filter>omit</filter>
<optiontype>triggeritem</optiontype>
<optiontype>coordinates</optiontype>
</signoptions>
<mimedata encoding="base64">
MIIFMgYJKoZIhvcNAQcCoIIFIzCCBR8CAQExDzANBgkgAQUFADALB\ngk
qhkiG9w0BBwGgggQZMCA36gAwSRiADjdhfHJl6hMrc5DySSP+X5j\nANf
BGSOI\n9w0BAQQwDwYDVQQHEwhJbn<Rlcm5ldDEXMBUGA1UEChM\nOVmV
yaVNpZ24sIEluYy4xNDAKn1ZlcmlTaWduIENsYXNzIDEgQ0Eg\nLSJbmR
dWFsIFN1YnNjcmliyZXIwHhcNOTgwMTI3MwMDAwOTgwM\M1OTU5WjCCAR
ExETA
</mimedata>
</signature>