PHP
Chilkat2 PHP
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.Note: This example requires Chilkat v9.5.0.85 or greater.
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<?php
use Chilkat2\DtObj;
use Chilkat2\JsonObject;
use Chilkat2\Pdf;
// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.
$pdf = new Pdf();
// Load a PDF that has cryptographic signatures to be validated
try {
$pdf->LoadFile('qa_data/pdf/sign_testing_1/helloSigned2.pdf');
} catch (\Chilkat2\Exception $e) {
echo $e->getMessage(), "\n";
exit;
}
// Each time we verify a signature, information about the signature is written into
// sigInfo (replacing whatever sigInfo previously contained).
$sigInfo = new JsonObject();
$sigInfo->EmitCompact = false;
// Iterate over each signature and validate each.
$numSignatures = $pdf->NumSignatures;
$validated = false;
$i = 0;
while ($i < $numSignatures) {
try {
$pdf->VerifySignature($i, $sigInfo);
$validated = true;
} catch (\Chilkat2\Exception $e) {
$validated = false;
}
echo 'Signature ', $i, ' validated: ', ($validated ? 'true' : 'false'), "\n";
echo $sigInfo->Emit(), "\n";
$i = $i + 1;
}
echo "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.
$json = new JsonObject();
// 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
$unauthAttrTimestampTokenTstInfoGenTime = new DtObj();
$signingTime = new DtObj();
$authAttrSigningTimeUtctime = new DtObj();
$intVal = 0;
$strVal = '';
$issuerCN = '';
$serial = '';
$certSerialNumber = '';
$certIssuerCN = '';
$certDigestAlgOid = '';
$certDigestAlgName = '';
$contentType = '';
$messageDigest = '';
$signingAlgOid = '';
$signingAlgName = '';
$authAttr1_2_840_113583_1_1_8Der = '';
$authAttrContentTypeName = '';
$authAttrContentTypeOid = '';
$authAttrMessageDigestName = '';
$authAttrMessageDigestDigest = '';
$unauthAttrTimestampTokenName = '';
$unauthAttrTimestampTokenDer = '';
$unauthAttrTimestampTokenTimestampSignatureVerified = false;
$unauthAttrTimestampTokenTstInfoTsaPolicyId = '';
$unauthAttrTimestampTokenTstInfoMessageImprintHashAlg = '';
$unauthAttrTimestampTokenTstInfoMessageImprintDigest = '';
$unauthAttrTimestampTokenTstInfoMessageImprintDigestMatches = false;
$unauthAttrTimestampTokenTstInfoSerialNumber = '';
$j = 0;
$count_j = 0;
$authAttrSigningTimeName = '';
$authAttrSigningCertificateName = '';
$authAttrSigningCertificateDer = '';
$validated = $json->BoolOf('validated');
$signatureDictionary_Contents = $json->StringOf('signatureDictionary./Contents');
$signatureDictionary_Filter = $json->StringOf('signatureDictionary./Filter');
$signatureDictionary_M = $json->StringOf('signatureDictionary./M');
$signatureDictionary_Name = $json->StringOf('signatureDictionary./Name');
$signatureDictionary_Prop_Build_App_Name = $json->StringOf('signatureDictionary./Prop_Build./App./Name');
$signatureDictionary_Prop_Build_App_R = $json->IntOf('signatureDictionary./Prop_Build./App./R');
$signatureDictionary_Prop_Build_App_REx = $json->StringOf('signatureDictionary./Prop_Build./App./REx');
$signatureDictionary_Prop_Build_App_TrustedMode = $json->BoolOf('signatureDictionary./Prop_Build./App./TrustedMode');
$signatureDictionary_Prop_Build_Filter_Date = $json->StringOf('signatureDictionary./Prop_Build./Filter./Date');
$signatureDictionary_Prop_Build_Filter_Name = $json->StringOf('signatureDictionary./Prop_Build./Filter./Name');
$signatureDictionary_Prop_Build_Filter_R = $json->IntOf('signatureDictionary./Prop_Build./Filter./R');
$signatureDictionary_Prop_Build_Filter_V = $json->IntOf('signatureDictionary./Prop_Build./Filter./V');
$signatureDictionary_Prop_Build_PubSec_Date = $json->StringOf('signatureDictionary./Prop_Build./PubSec./Date');
$signatureDictionary_Prop_Build_PubSec_NonEFontNoWarn = $json->BoolOf('signatureDictionary./Prop_Build./PubSec./NonEFontNoWarn');
$signatureDictionary_Prop_Build_PubSec_R = $json->IntOf('signatureDictionary./Prop_Build./PubSec./R');
$signatureDictionary_SubFilter = $json->StringOf('signatureDictionary./SubFilter');
$signatureDictionary_Type = $json->StringOf('signatureDictionary./Type');
$i = 0;
$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', false, $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', false, $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', false, $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;
}