Perl Requires Chilkat v9.5.0.85+
Chilkat2 Perl
Validate PDF Signatures
See more PDF Signatures Examples
This example demonstrates how to validate the signatures in a PDF and also shows how to get information from each signature.Chilkat Perl Downloads
use strict;
use warnings;
use Chilkat2;
# This example requires the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.
my $pdf = Chilkat2::Pdf->new;
# Load a PDF that has cryptographic signatures to be validated
my $success = $pdf->LoadFile('qa_data/pdf/sign_testing_1/helloSigned2.pdf');
if (!$success) {
print $pdf->LastErrorText, "\n";
exit;
}
# Each time we verify a signature, information about the signature is written into
# sigInfo (replacing whatever sigInfo previously contained).
my $sigInfo = Chilkat2::JsonObject->new;
$sigInfo->EmitCompact(0);
# Iterate over each signature and validate each.
my $numSignatures = $pdf->NumSignatures;
my $validated = 0;
my $i = 0;
while ($i < $numSignatures) {
$validated = $pdf->VerifySignature($i, $sigInfo);
print 'Signature ', $i, ' validated: ', ($validated ? 1 : 0), "\n";
print $sigInfo->Emit(), "\n";
$i = $i + 1;
}
print "Finished.\n";
# When VerifySignature validates a signature, a lot of information is deposited into the JSON sigInfo object.
# The information can vary depending on what was included in the signature (for example, various authenticated attributes
# and unauthenticated attributes may or may not be included).
# Here is a sample of the information you'll see.
#
# The following online tool can be used to generate code to parse any given JSON.
# Generate Parsing Code from JSON
# {
# "validated": true,
# "signatureDictionary": { <--- This is the contents of the PDF Signature Dictionary for this signature.
# "/ByteRange": [
# 0,
# 154682,
# 170512,
# 3233
# ],
# "/Contents": "<hex_data>",
# "/Filter": "/Adobe.PPKLite", <--- The meaning of the Signature Dictionary entries are defined in the PDF format specification document.
# "/M": "D:20201006110216-05'00'",
# "/Name": "yubikey rsa 1024 authentication",
# "/Prop_Build": {
# "/App": {
# "/Name": "/Adobe#20Acrobat#20Pro#20DC",
# "/OS": [
# "/Win"
# ],
# "/R": 1313792,
# "/REx": "2020.012.20048",
# "/TrustedMode": true
# },
# "/Filter": {
# "/Date": "Sep 11 2020 16:30:54",
# "/Name": "/Adobe.PPKLite",
# "/R": 131104,
# "/V": 2
# },
# "/PubSec": {
# "/Date": "Sep 11 2020 16:30:54",
# "/NonEFontNoWarn": true,
# "/R": 131105
# }
# },
# "/SubFilter": "/adbe.pkcs7.detached",
# "/Type": "/Sig"
# },
# "pkcs7": { <--- This is the content of the CMS signature.
# "verify": {
# "certs": [ <--- Each signing certificate is listed here (by issuer common name and signing cert's serail number (in hex))
# {
# "issuerCN": "yubikey rsa 1024 authentication",
# "serial": "66BE58138D761E92BC594A722932657BE26D421F"
# }
# ],
# "digestAlgorithms": [
# "sha256"
# ],
# "signerInfo": [ <--- contains data from each SignerInfo
# {
# "cert": {
# "serialNumber": "66BE58138D761E92BC594A722932657BE26D421F",
# "issuerCN": "yubikey rsa 1024 authentication",
# "digestAlgOid": "2.16.840.1.101.3.4.2.1",
# "digestAlgName": "SHA256"
# },
# "contentType": "1.2.840.113549.1.7.1",
# "messageDigest": "btQOuSEvC31mdRFHtyEUPw8R9NuKfk0XPcQ6Lcmn6pk=",
# "signingAlgOid": "1.2.840.113549.1.1.11",
# "signingAlgName": "RSA-SHA256-PKCSV-1_5",
# "authAttr": { <--- CMS authenticated attributes are contained here.
# "1.2.840.113583.1.1.8": {
# "der": "MAA="
# },
# "1.2.840.113549.1.9.3": {
# "name": "contentType",
# "oid": "1.2.840.113549.1.7.1"
# },
# "1.2.840.113549.1.9.4": {
# "name": "messageDigest",
# "digest": "btQOuSEvC31mdRFHtyEUPw8R9NuKfk0XPcQ6Lcmn6pk="
# }
# },
# "unauthAttr": { <--- CMS unauthenticated attributes are contained here.
# "1.2.840.113549.1.9.16.2.14": {
# "name": "timestampToken",
# "der": "MIIOvAYJKo ... Es/70g=",
# "verify": {
# "digestAlgorithms": [
# "sha256"
# ],
# "signerInfo": [
# {
# "cert": {
# "serialNumber": "04CD3F8568AE76C61BB0FE7160CCA76D",
# "issuerCN": "DigiCert SHA2 Assured ID Timestamping CA",
# "digestAlgOid": "2.16.840.1.101.3.4.2.1",
# "digestAlgName": "SHA256"
# },
# "contentType": "1.2.840.113549.1.9.16.1.4",
# "signingTime": "201006160423Z",
# "messageDigest": "Atv5Rj3kidB8IR6CplYiX3o6De/k8SC6JJ6uUPAGO0g=",
# "signingAlgOid": "1.2.840.113549.1.1.1",
# "signingAlgName": "RSA-PKCSV-1_5",
# "authAttr": {
# "1.2.840.113549.1.9.3": {
# "name": "contentType",
# "oid": "1.2.840.113549.1.9.16.1.4"
# },
# "1.2.840.113549.1.9.5": {
# "name": "signingTime",
# "utctime": "201006160423Z"
# },
# "1.2.840.113549.1.9.16.2.12": {
# "name": "signingCertificate",
# "der": "MBowGDAWBBQDJb1QXtqWMC3CL0+gHkwovig0xQ=="
# },
# "1.2.840.113549.1.9.4": {
# "name": "messageDigest",
# "digest": "Atv5Rj3kidB8IR6CplYiX3o6De/k8SC6JJ6uUPAGO0g="
# }
# }
# }
# ]
# },
# "timestampSignatureVerified": true,
# "tstInfo": {
# "tsaPolicyId": "2.16.840.1.114412.7.1",
# "messageImprint": {
# "hashAlg": "sha256",
# "digest": "gLJtrRWUSDfjzDkF1MfWG1wyHA6FrUJLkWMGRG+eMlA=",
# "digestMatches": true
# },
# "serialNumber": "00CE57E1113970607EF63B1D1160545321",
# "genTime": "20201006160423Z"
# }
# }
# }
# }
# ],
# "pkcs7": {
# "verify": {
# "certs": [
# {
# "issuerCN": "DigiCert SHA2 Assured ID Timestamping CA",
# "serial": "04CD3F8568AE76C61BB0FE7160CCA76D"
# },
# {
# "issuerCN": "DigiCert Assured ID Root CA",
# "serial": "0AA125D6D6321B7E41E405DA3697C215"
# }
# ]
# }
# }
# }
# }
# }
# **** The point of this code is to show how to get at each desired piece of information contained in the signature.
# **** If your signature contains additional information not shown here, then you can use the online tool to generate the parse code.
# **** It is likely you're only interested in a few items of information, and therefore you wouldn't copy all of this code, but might
# **** choose to use bits and pieces to get the information you find important.
my $json = Chilkat2::JsonObject->new;
# Imagine that the "json" object contains the information obtained by validating a signature...
# The code below was generated using the online tool: Generate Parsing Code from JSON
my $unauthAttrTimestampTokenTstInfoGenTime = Chilkat2::DtObj->new;
my $signingTime = Chilkat2::DtObj->new;
my $authAttrSigningTimeUtctime = Chilkat2::DtObj->new;
my $intVal = 0;
my $strVal = '';
my $issuerCN = '';
my $serial = '';
my $certSerialNumber = '';
my $certIssuerCN = '';
my $certDigestAlgOid = '';
my $certDigestAlgName = '';
my $contentType = '';
my $messageDigest = '';
my $signingAlgOid = '';
my $signingAlgName = '';
my $authAttr1_2_840_113583_1_1_8Der = '';
my $authAttrContentTypeName = '';
my $authAttrContentTypeOid = '';
my $authAttrMessageDigestName = '';
my $authAttrMessageDigestDigest = '';
my $unauthAttrTimestampTokenName = '';
my $unauthAttrTimestampTokenDer = '';
my $unauthAttrTimestampTokenTimestampSignatureVerified = 0;
my $unauthAttrTimestampTokenTstInfoTsaPolicyId = '';
my $unauthAttrTimestampTokenTstInfoMessageImprintHashAlg = '';
my $unauthAttrTimestampTokenTstInfoMessageImprintDigest = '';
my $unauthAttrTimestampTokenTstInfoMessageImprintDigestMatches = 0;
my $unauthAttrTimestampTokenTstInfoSerialNumber = '';
my $j = 0;
my $count_j = 0;
my $authAttrSigningTimeName = '';
my $authAttrSigningCertificateName = '';
my $authAttrSigningCertificateDer = '';
$validated = $json->BoolOf('validated');
my $signatureDictionary_Contents = $json->StringOf('signatureDictionary./Contents');
my $signatureDictionary_Filter = $json->StringOf('signatureDictionary./Filter');
my $signatureDictionary_M = $json->StringOf('signatureDictionary./M');
my $signatureDictionary_Name = $json->StringOf('signatureDictionary./Name');
my $signatureDictionary_Prop_Build_App_Name = $json->StringOf('signatureDictionary./Prop_Build./App./Name');
my $signatureDictionary_Prop_Build_App_R = $json->IntOf('signatureDictionary./Prop_Build./App./R');
my $signatureDictionary_Prop_Build_App_REx = $json->StringOf('signatureDictionary./Prop_Build./App./REx');
my $signatureDictionary_Prop_Build_App_TrustedMode = $json->BoolOf('signatureDictionary./Prop_Build./App./TrustedMode');
my $signatureDictionary_Prop_Build_Filter_Date = $json->StringOf('signatureDictionary./Prop_Build./Filter./Date');
my $signatureDictionary_Prop_Build_Filter_Name = $json->StringOf('signatureDictionary./Prop_Build./Filter./Name');
my $signatureDictionary_Prop_Build_Filter_R = $json->IntOf('signatureDictionary./Prop_Build./Filter./R');
my $signatureDictionary_Prop_Build_Filter_V = $json->IntOf('signatureDictionary./Prop_Build./Filter./V');
my $signatureDictionary_Prop_Build_PubSec_Date = $json->StringOf('signatureDictionary./Prop_Build./PubSec./Date');
my $signatureDictionary_Prop_Build_PubSec_NonEFontNoWarn = $json->BoolOf('signatureDictionary./Prop_Build./PubSec./NonEFontNoWarn');
my $signatureDictionary_Prop_Build_PubSec_R = $json->IntOf('signatureDictionary./Prop_Build./PubSec./R');
my $signatureDictionary_SubFilter = $json->StringOf('signatureDictionary./SubFilter');
my $signatureDictionary_Type = $json->StringOf('signatureDictionary./Type');
$i = 0;
my $count_i = $json->SizeOfArray('signatureDictionary./ByteRange');
while ($i < $count_i) {
$json->I($i);
$intVal = $json->IntOf('signatureDictionary./ByteRange[i]');
$i = $i + 1;
}
$i = 0;
$count_i = $json->SizeOfArray('signatureDictionary./Prop_Build./App./OS');
while ($i < $count_i) {
$json->I($i);
$strVal = $json->StringOf('signatureDictionary./Prop_Build./App./OS[i]');
$i = $i + 1;
}
$i = 0;
$count_i = $json->SizeOfArray('pkcs7.verify.certs');
while ($i < $count_i) {
$json->I($i);
$issuerCN = $json->StringOf('pkcs7.verify.certs[i].issuerCN');
$serial = $json->StringOf('pkcs7.verify.certs[i].serial');
$i = $i + 1;
}
$i = 0;
$count_i = $json->SizeOfArray('pkcs7.verify.digestAlgorithms');
while ($i < $count_i) {
$json->I($i);
$strVal = $json->StringOf('pkcs7.verify.digestAlgorithms[i]');
$i = $i + 1;
}
$i = 0;
$count_i = $json->SizeOfArray('pkcs7.verify.signerInfo');
while ($i < $count_i) {
$json->I($i);
$certSerialNumber = $json->StringOf('pkcs7.verify.signerInfo[i].cert.serialNumber');
$certIssuerCN = $json->StringOf('pkcs7.verify.signerInfo[i].cert.issuerCN');
$certDigestAlgOid = $json->StringOf('pkcs7.verify.signerInfo[i].cert.digestAlgOid');
$certDigestAlgName = $json->StringOf('pkcs7.verify.signerInfo[i].cert.digestAlgName');
$contentType = $json->StringOf('pkcs7.verify.signerInfo[i].contentType');
$messageDigest = $json->StringOf('pkcs7.verify.signerInfo[i].messageDigest');
$signingAlgOid = $json->StringOf('pkcs7.verify.signerInfo[i].signingAlgOid');
$signingAlgName = $json->StringOf('pkcs7.verify.signerInfo[i].signingAlgName');
$authAttr1_2_840_113583_1_1_8Der = $json->StringOf('pkcs7.verify.signerInfo[i].authAttr."1.2.840.113583.1.1.8".der');
$authAttrContentTypeName = $json->StringOf('pkcs7.verify.signerInfo[i].authAttr."1.2.840.113549.1.9.3".name');
$authAttrContentTypeOid = $json->StringOf('pkcs7.verify.signerInfo[i].authAttr."1.2.840.113549.1.9.3".oid');
$authAttrMessageDigestName = $json->StringOf('pkcs7.verify.signerInfo[i].authAttr."1.2.840.113549.1.9.4".name');
$authAttrMessageDigestDigest = $json->StringOf('pkcs7.verify.signerInfo[i].authAttr."1.2.840.113549.1.9.4".digest');
$unauthAttrTimestampTokenName = $json->StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".name');
$unauthAttrTimestampTokenDer = $json->StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".der');
$unauthAttrTimestampTokenTimestampSignatureVerified = $json->BoolOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".timestampSignatureVerified');
$unauthAttrTimestampTokenTstInfoTsaPolicyId = $json->StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".tstInfo.tsaPolicyId');
$unauthAttrTimestampTokenTstInfoMessageImprintHashAlg = $json->StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".tstInfo.messageImprint.hashAlg');
$unauthAttrTimestampTokenTstInfoMessageImprintDigest = $json->StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".tstInfo.messageImprint.digest');
$unauthAttrTimestampTokenTstInfoMessageImprintDigestMatches = $json->BoolOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".tstInfo.messageImprint.digestMatches');
$unauthAttrTimestampTokenTstInfoSerialNumber = $json->StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".tstInfo.serialNumber');
$json->DtOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".tstInfo.genTime', 0, $unauthAttrTimestampTokenTstInfoGenTime);
$j = 0;
$count_j = $json->SizeOfArray('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.digestAlgorithms');
while ($j < $count_j) {
$json->J($j);
$strVal = $json->StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.digestAlgorithms[j]');
$j = $j + 1;
}
$j = 0;
$count_j = $json->SizeOfArray('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo');
while ($j < $count_j) {
$json->J($j);
$certSerialNumber = $json->StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].cert.serialNumber');
$certIssuerCN = $json->StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].cert.issuerCN');
$certDigestAlgOid = $json->StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].cert.digestAlgOid');
$certDigestAlgName = $json->StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].cert.digestAlgName');
$contentType = $json->StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].contentType');
$json->DtOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].signingTime', 0, $signingTime);
$messageDigest = $json->StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].messageDigest');
$signingAlgOid = $json->StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].signingAlgOid');
$signingAlgName = $json->StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].signingAlgName');
$authAttrContentTypeName = $json->StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].authAttr."1.2.840.113549.1.9.3".name');
$authAttrContentTypeOid = $json->StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].authAttr."1.2.840.113549.1.9.3".oid');
$authAttrSigningTimeName = $json->StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].authAttr."1.2.840.113549.1.9.5".name');
$json->DtOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].authAttr."1.2.840.113549.1.9.5".utctime', 0, $authAttrSigningTimeUtctime);
$authAttrSigningCertificateName = $json->StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].authAttr."1.2.840.113549.1.9.16.2.12".name');
$authAttrSigningCertificateDer = $json->StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].authAttr."1.2.840.113549.1.9.16.2.12".der');
$authAttrMessageDigestName = $json->StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].authAttr."1.2.840.113549.1.9.4".name');
$authAttrMessageDigestDigest = $json->StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].authAttr."1.2.840.113549.1.9.4".digest');
$j = $j + 1;
}
$i = $i + 1;
}
$i = 0;
$count_i = $json->SizeOfArray('pkcs7.verify.pkcs7.verify.certs');
while ($i < $count_i) {
$json->I($i);
$issuerCN = $json->StringOf('pkcs7.verify.pkcs7.verify.certs[i].issuerCN');
$serial = $json->StringOf('pkcs7.verify.pkcs7.verify.certs[i].serial');
$i = $i + 1;
}