Lianja
Lianja
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.
Chilkat Lianja Downloads
llSuccess = .F.
// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.
loPdf = createobject("CkPdf")
// Load a PDF that has cryptographic signatures to be validated
llSuccess = loPdf.LoadFile("qa_data/pdf/sign_testing_1/helloSigned2.pdf")
if (llSuccess = .F.) then
? loPdf.LastErrorText
release loPdf
return
endif
// Each time we verify a signature, information about the signature is written into
// sigInfo (replacing whatever sigInfo previously contained).
loSigInfo = createobject("CkJsonObject")
loSigInfo.EmitCompact = .F.
// Iterate over each signature and validate each.
lnNumSignatures = loPdf.NumSignatures
llValidated = .F.
i = 0
do while i < lnNumSignatures
llValidated = loPdf.VerifySignature(i,loSigInfo)
? "Signature " + str(i) + " validated: " + str(llValidated)
? loSigInfo.Emit()
i = i + 1
enddo
? "Finished."
// 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.
loJson = createobject("CkJsonObject")
// 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
loUnauthAttrTimestampTokenTstInfoGenTime = createobject("CkDtObj")
loSigningTime = createobject("CkDtObj")
loAuthAttrSigningTimeUtctime = createobject("CkDtObj")
llValidated = loJson.BoolOf("validated")
lcSignatureDictionary_Contents = loJson.StringOf("signatureDictionary./Contents")
lcSignatureDictionary_Filter = loJson.StringOf("signatureDictionary./Filter")
lcSignatureDictionary_M = loJson.StringOf("signatureDictionary./M")
lcSignatureDictionary_Name = loJson.StringOf("signatureDictionary./Name")
lcSignatureDictionary_Prop_Build_App_Name = loJson.StringOf("signatureDictionary./Prop_Build./App./Name")
lnSignatureDictionary_Prop_Build_App_R = loJson.IntOf("signatureDictionary./Prop_Build./App./R")
lcSignatureDictionary_Prop_Build_App_REx = loJson.StringOf("signatureDictionary./Prop_Build./App./REx")
llSignatureDictionary_Prop_Build_App_TrustedMode = loJson.BoolOf("signatureDictionary./Prop_Build./App./TrustedMode")
lcSignatureDictionary_Prop_Build_Filter_Date = loJson.StringOf("signatureDictionary./Prop_Build./Filter./Date")
lcSignatureDictionary_Prop_Build_Filter_Name = loJson.StringOf("signatureDictionary./Prop_Build./Filter./Name")
lnSignatureDictionary_Prop_Build_Filter_R = loJson.IntOf("signatureDictionary./Prop_Build./Filter./R")
lnSignatureDictionary_Prop_Build_Filter_V = loJson.IntOf("signatureDictionary./Prop_Build./Filter./V")
lcSignatureDictionary_Prop_Build_PubSec_Date = loJson.StringOf("signatureDictionary./Prop_Build./PubSec./Date")
llSignatureDictionary_Prop_Build_PubSec_NonEFontNoWarn = loJson.BoolOf("signatureDictionary./Prop_Build./PubSec./NonEFontNoWarn")
lnSignatureDictionary_Prop_Build_PubSec_R = loJson.IntOf("signatureDictionary./Prop_Build./PubSec./R")
lcSignatureDictionary_SubFilter = loJson.StringOf("signatureDictionary./SubFilter")
lcSignatureDictionary_Type = loJson.StringOf("signatureDictionary./Type")
i = 0
lnCount_i = loJson.SizeOfArray("signatureDictionary./ByteRange")
do while i < lnCount_i
loJson.I = i
lnIntVal = loJson.IntOf("signatureDictionary./ByteRange[i]")
i = i + 1
enddo
i = 0
lnCount_i = loJson.SizeOfArray("signatureDictionary./Prop_Build./App./OS")
do while i < lnCount_i
loJson.I = i
lcStrVal = loJson.StringOf("signatureDictionary./Prop_Build./App./OS[i]")
i = i + 1
enddo
i = 0
lnCount_i = loJson.SizeOfArray("pkcs7.verify.certs")
do while i < lnCount_i
loJson.I = i
lcIssuerCN = loJson.StringOf("pkcs7.verify.certs[i].issuerCN")
lcSerial = loJson.StringOf("pkcs7.verify.certs[i].serial")
i = i + 1
enddo
i = 0
lnCount_i = loJson.SizeOfArray("pkcs7.verify.digestAlgorithms")
do while i < lnCount_i
loJson.I = i
lcStrVal = loJson.StringOf("pkcs7.verify.digestAlgorithms[i]")
i = i + 1
enddo
i = 0
lnCount_i = loJson.SizeOfArray("pkcs7.verify.signerInfo")
do while i < lnCount_i
loJson.I = i
lcCertSerialNumber = loJson.StringOf("pkcs7.verify.signerInfo[i].cert.serialNumber")
lcCertIssuerCN = loJson.StringOf("pkcs7.verify.signerInfo[i].cert.issuerCN")
lcCertDigestAlgOid = loJson.StringOf("pkcs7.verify.signerInfo[i].cert.digestAlgOid")
lcCertDigestAlgName = loJson.StringOf("pkcs7.verify.signerInfo[i].cert.digestAlgName")
lcContentType = loJson.StringOf("pkcs7.verify.signerInfo[i].contentType")
lcMessageDigest = loJson.StringOf("pkcs7.verify.signerInfo[i].messageDigest")
lcSigningAlgOid = loJson.StringOf("pkcs7.verify.signerInfo[i].signingAlgOid")
lcSigningAlgName = loJson.StringOf("pkcs7.verify.signerInfo[i].signingAlgName")
lcAuthAttr1_2_840_113583_1_1_8Der = loJson.StringOf('pkcs7.verify.signerInfo[i].authAttr."1.2.840.113583.1.1.8".der')
lcAuthAttrContentTypeName = loJson.StringOf('pkcs7.verify.signerInfo[i].authAttr."1.2.840.113549.1.9.3".name')
lcAuthAttrContentTypeOid = loJson.StringOf('pkcs7.verify.signerInfo[i].authAttr."1.2.840.113549.1.9.3".oid')
lcAuthAttrMessageDigestName = loJson.StringOf('pkcs7.verify.signerInfo[i].authAttr."1.2.840.113549.1.9.4".name')
lcAuthAttrMessageDigestDigest = loJson.StringOf('pkcs7.verify.signerInfo[i].authAttr."1.2.840.113549.1.9.4".digest')
lcUnauthAttrTimestampTokenName = loJson.StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".name')
lcUnauthAttrTimestampTokenDer = loJson.StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".der')
llUnauthAttrTimestampTokenTimestampSignatureVerified = loJson.BoolOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".timestampSignatureVerified')
lcUnauthAttrTimestampTokenTstInfoTsaPolicyId = loJson.StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".tstInfo.tsaPolicyId')
lcUnauthAttrTimestampTokenTstInfoMessageImprintHashAlg = loJson.StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".tstInfo.messageImprint.hashAlg')
lcUnauthAttrTimestampTokenTstInfoMessageImprintDigest = loJson.StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".tstInfo.messageImprint.digest')
llUnauthAttrTimestampTokenTstInfoMessageImprintDigestMatches = loJson.BoolOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".tstInfo.messageImprint.digestMatches')
lcUnauthAttrTimestampTokenTstInfoSerialNumber = loJson.StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".tstInfo.serialNumber')
loJson.DtOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".tstInfo.genTime',.F.,loUnauthAttrTimestampTokenTstInfoGenTime)
j = 0
lnCount_j = loJson.SizeOfArray('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.digestAlgorithms')
do while j < lnCount_j
loJson.J = j
lcStrVal = loJson.StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.digestAlgorithms[j]')
j = j + 1
enddo
j = 0
lnCount_j = loJson.SizeOfArray('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo')
do while j < lnCount_j
loJson.J = j
lcCertSerialNumber = loJson.StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].cert.serialNumber')
lcCertIssuerCN = loJson.StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].cert.issuerCN')
lcCertDigestAlgOid = loJson.StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].cert.digestAlgOid')
lcCertDigestAlgName = loJson.StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].cert.digestAlgName')
lcContentType = loJson.StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].contentType')
loJson.DtOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].signingTime',.F.,loSigningTime)
lcMessageDigest = loJson.StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].messageDigest')
lcSigningAlgOid = loJson.StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].signingAlgOid')
lcSigningAlgName = loJson.StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].signingAlgName')
lcAuthAttrContentTypeName = loJson.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')
lcAuthAttrContentTypeOid = loJson.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')
lcAuthAttrSigningTimeName = loJson.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')
loJson.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',.F.,loAuthAttrSigningTimeUtctime)
lcAuthAttrSigningCertificateName = loJson.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')
lcAuthAttrSigningCertificateDer = loJson.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')
lcAuthAttrMessageDigestName = loJson.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')
lcAuthAttrMessageDigestDigest = loJson.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
enddo
i = i + 1
enddo
i = 0
lnCount_i = loJson.SizeOfArray("pkcs7.verify.pkcs7.verify.certs")
do while i < lnCount_i
loJson.I = i
lcIssuerCN = loJson.StringOf("pkcs7.verify.pkcs7.verify.certs[i].issuerCN")
lcSerial = loJson.StringOf("pkcs7.verify.pkcs7.verify.certs[i].serial")
i = i + 1
enddo
release loPdf
release loSigInfo
release loJson
release loUnauthAttrTimestampTokenTstInfoGenTime
release loSigningTime
release loAuthAttrSigningTimeUtctime