Xbase++
Xbase++
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 Xbase++ Downloads
LOCAL nSuccess
LOCAL oPdf
LOCAL oSigInfo
LOCAL nNumSignatures
LOCAL nValidated
LOCAL i
LOCAL oJson
LOCAL oUnauthAttrTimestampTokenTstInfoGenTime
LOCAL oSigningTime
LOCAL oAuthAttrSigningTimeUtctime
LOCAL nIntVal
LOCAL cStrVal
LOCAL cIssuerCN
LOCAL cSerial
LOCAL cCertSerialNumber
LOCAL cCertIssuerCN
LOCAL cCertDigestAlgOid
LOCAL cCertDigestAlgName
LOCAL cContentType
LOCAL cMessageDigest
LOCAL cSigningAlgOid
LOCAL cSigningAlgName
LOCAL cAuthAttr1_2_840_113583_1_1_8Der
LOCAL cAuthAttrContentTypeName
LOCAL cAuthAttrContentTypeOid
LOCAL cAuthAttrMessageDigestName
LOCAL cAuthAttrMessageDigestDigest
LOCAL cUnauthAttrTimestampTokenName
LOCAL cUnauthAttrTimestampTokenDer
LOCAL nUnauthAttrTimestampTokenTimestampSignatureVerified
LOCAL cUnauthAttrTimestampTokenTstInfoTsaPolicyId
LOCAL cUnauthAttrTimestampTokenTstInfoMessageImprintHashAlg
LOCAL cUnauthAttrTimestampTokenTstInfoMessageImprintDigest
LOCAL nUnauthAttrTimestampTokenTstInfoMessageImprintDigestMatches
LOCAL cUnauthAttrTimestampTokenTstInfoSerialNumber
LOCAL j
LOCAL nCount_j
LOCAL cAuthAttrSigningTimeName
LOCAL cAuthAttrSigningCertificateName
LOCAL cAuthAttrSigningCertificateDer
LOCAL cSignatureDictionary_Contents
LOCAL cSignatureDictionary_Filter
LOCAL cSignatureDictionary_M
LOCAL cSignatureDictionary_Name
LOCAL cSignatureDictionary_Prop_Build_App_Name
LOCAL nSignatureDictionary_Prop_Build_App_R
LOCAL cSignatureDictionary_Prop_Build_App_REx
LOCAL nSignatureDictionary_Prop_Build_App_TrustedMode
LOCAL cSignatureDictionary_Prop_Build_Filter_Date
LOCAL cSignatureDictionary_Prop_Build_Filter_Name
LOCAL nSignatureDictionary_Prop_Build_Filter_R
LOCAL nSignatureDictionary_Prop_Build_Filter_V
LOCAL cSignatureDictionary_Prop_Build_PubSec_Date
LOCAL nSignatureDictionary_Prop_Build_PubSec_NonEFontNoWarn
LOCAL nSignatureDictionary_Prop_Build_PubSec_R
LOCAL cSignatureDictionary_SubFilter
LOCAL cSignatureDictionary_Type
LOCAL nCount_i
nSuccess := 0
// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.
oPdf := CreateObject("Chilkat.Pdf")
// Load a PDF that has cryptographic signatures to be validated
nSuccess := oPdf:LoadFile("qa_data/pdf/sign_testing_1/helloSigned2.pdf")
IF (nSuccess == 0)
? oPdf:LastErrorText
oPdf:destroy()
RETURN
ENDIF
// Each time we verify a signature, information about the signature is written into
// sigInfo (replacing whatever sigInfo previously contained).
oSigInfo := CreateObject("Chilkat.JsonObject")
oSigInfo:EmitCompact := 0
// Iterate over each signature and validate each.
nNumSignatures := oPdf:NumSignatures
nValidated := 0
i := 0
DO WHILE i < nNumSignatures
nValidated := oPdf:VerifySignature(i, oSigInfo)
? "Signature " + Str(i) + " validated: " + Str(nValidated)
? oSigInfo: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.
oJson := CreateObject("Chilkat.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
oUnauthAttrTimestampTokenTstInfoGenTime := CreateObject("Chilkat.DtObj")
oSigningTime := CreateObject("Chilkat.DtObj")
oAuthAttrSigningTimeUtctime := CreateObject("Chilkat.DtObj")
nValidated := oJson:BoolOf("validated")
cSignatureDictionary_Contents := oJson:StringOf("signatureDictionary./Contents")
cSignatureDictionary_Filter := oJson:StringOf("signatureDictionary./Filter")
cSignatureDictionary_M := oJson:StringOf("signatureDictionary./M")
cSignatureDictionary_Name := oJson:StringOf("signatureDictionary./Name")
cSignatureDictionary_Prop_Build_App_Name := oJson:StringOf("signatureDictionary./Prop_Build./App./Name")
nSignatureDictionary_Prop_Build_App_R := oJson:IntOf("signatureDictionary./Prop_Build./App./R")
cSignatureDictionary_Prop_Build_App_REx := oJson:StringOf("signatureDictionary./Prop_Build./App./REx")
nSignatureDictionary_Prop_Build_App_TrustedMode := oJson:BoolOf("signatureDictionary./Prop_Build./App./TrustedMode")
cSignatureDictionary_Prop_Build_Filter_Date := oJson:StringOf("signatureDictionary./Prop_Build./Filter./Date")
cSignatureDictionary_Prop_Build_Filter_Name := oJson:StringOf("signatureDictionary./Prop_Build./Filter./Name")
nSignatureDictionary_Prop_Build_Filter_R := oJson:IntOf("signatureDictionary./Prop_Build./Filter./R")
nSignatureDictionary_Prop_Build_Filter_V := oJson:IntOf("signatureDictionary./Prop_Build./Filter./V")
cSignatureDictionary_Prop_Build_PubSec_Date := oJson:StringOf("signatureDictionary./Prop_Build./PubSec./Date")
nSignatureDictionary_Prop_Build_PubSec_NonEFontNoWarn := oJson:BoolOf("signatureDictionary./Prop_Build./PubSec./NonEFontNoWarn")
nSignatureDictionary_Prop_Build_PubSec_R := oJson:IntOf("signatureDictionary./Prop_Build./PubSec./R")
cSignatureDictionary_SubFilter := oJson:StringOf("signatureDictionary./SubFilter")
cSignatureDictionary_Type := oJson:StringOf("signatureDictionary./Type")
i := 0
nCount_i := oJson:SizeOfArray("signatureDictionary./ByteRange")
DO WHILE i < nCount_i
oJson:I := i
nIntVal := oJson:IntOf("signatureDictionary./ByteRange[i]")
i := i + 1
ENDDO
i := 0
nCount_i := oJson:SizeOfArray("signatureDictionary./Prop_Build./App./OS")
DO WHILE i < nCount_i
oJson:I := i
cStrVal := oJson:StringOf("signatureDictionary./Prop_Build./App./OS[i]")
i := i + 1
ENDDO
i := 0
nCount_i := oJson:SizeOfArray("pkcs7.verify.certs")
DO WHILE i < nCount_i
oJson:I := i
cIssuerCN := oJson:StringOf("pkcs7.verify.certs[i].issuerCN")
cSerial := oJson:StringOf("pkcs7.verify.certs[i].serial")
i := i + 1
ENDDO
i := 0
nCount_i := oJson:SizeOfArray("pkcs7.verify.digestAlgorithms")
DO WHILE i < nCount_i
oJson:I := i
cStrVal := oJson:StringOf("pkcs7.verify.digestAlgorithms[i]")
i := i + 1
ENDDO
i := 0
nCount_i := oJson:SizeOfArray("pkcs7.verify.signerInfo")
DO WHILE i < nCount_i
oJson:I := i
cCertSerialNumber := oJson:StringOf("pkcs7.verify.signerInfo[i].cert.serialNumber")
cCertIssuerCN := oJson:StringOf("pkcs7.verify.signerInfo[i].cert.issuerCN")
cCertDigestAlgOid := oJson:StringOf("pkcs7.verify.signerInfo[i].cert.digestAlgOid")
cCertDigestAlgName := oJson:StringOf("pkcs7.verify.signerInfo[i].cert.digestAlgName")
cContentType := oJson:StringOf("pkcs7.verify.signerInfo[i].contentType")
cMessageDigest := oJson:StringOf("pkcs7.verify.signerInfo[i].messageDigest")
cSigningAlgOid := oJson:StringOf("pkcs7.verify.signerInfo[i].signingAlgOid")
cSigningAlgName := oJson:StringOf("pkcs7.verify.signerInfo[i].signingAlgName")
cAuthAttr1_2_840_113583_1_1_8Der := oJson:StringOf('pkcs7.verify.signerInfo[i].authAttr."1.2.840.113583.1.1.8".der')
cAuthAttrContentTypeName := oJson:StringOf('pkcs7.verify.signerInfo[i].authAttr."1.2.840.113549.1.9.3".name')
cAuthAttrContentTypeOid := oJson:StringOf('pkcs7.verify.signerInfo[i].authAttr."1.2.840.113549.1.9.3".oid')
cAuthAttrMessageDigestName := oJson:StringOf('pkcs7.verify.signerInfo[i].authAttr."1.2.840.113549.1.9.4".name')
cAuthAttrMessageDigestDigest := oJson:StringOf('pkcs7.verify.signerInfo[i].authAttr."1.2.840.113549.1.9.4".digest')
cUnauthAttrTimestampTokenName := oJson:StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".name')
cUnauthAttrTimestampTokenDer := oJson:StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".der')
nUnauthAttrTimestampTokenTimestampSignatureVerified := oJson:BoolOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".timestampSignatureVerified')
cUnauthAttrTimestampTokenTstInfoTsaPolicyId := oJson:StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".tstInfo.tsaPolicyId')
cUnauthAttrTimestampTokenTstInfoMessageImprintHashAlg := oJson:StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".tstInfo.messageImprint.hashAlg')
cUnauthAttrTimestampTokenTstInfoMessageImprintDigest := oJson:StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".tstInfo.messageImprint.digest')
nUnauthAttrTimestampTokenTstInfoMessageImprintDigestMatches := oJson:BoolOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".tstInfo.messageImprint.digestMatches')
cUnauthAttrTimestampTokenTstInfoSerialNumber := oJson:StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".tstInfo.serialNumber')
oJson:DtOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".tstInfo.genTime', 0, oUnauthAttrTimestampTokenTstInfoGenTime)
j := 0
nCount_j := oJson:SizeOfArray('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.digestAlgorithms')
DO WHILE j < nCount_j
oJson:J := j
cStrVal := oJson:StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.digestAlgorithms[j]')
j := j + 1
ENDDO
j := 0
nCount_j := oJson:SizeOfArray('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo')
DO WHILE j < nCount_j
oJson:J := j
cCertSerialNumber := oJson:StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].cert.serialNumber')
cCertIssuerCN := oJson:StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].cert.issuerCN')
cCertDigestAlgOid := oJson:StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].cert.digestAlgOid')
cCertDigestAlgName := oJson:StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].cert.digestAlgName')
cContentType := oJson:StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].contentType')
oJson:DtOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].signingTime', 0, oSigningTime)
cMessageDigest := oJson:StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].messageDigest')
cSigningAlgOid := oJson:StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].signingAlgOid')
cSigningAlgName := oJson:StringOf('pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].signingAlgName')
cAuthAttrContentTypeName := oJson: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')
cAuthAttrContentTypeOid := oJson: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')
cAuthAttrSigningTimeName := oJson: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')
oJson: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, oAuthAttrSigningTimeUtctime)
cAuthAttrSigningCertificateName := oJson: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')
cAuthAttrSigningCertificateDer := oJson: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')
cAuthAttrMessageDigestName := oJson: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')
cAuthAttrMessageDigestDigest := oJson: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
nCount_i := oJson:SizeOfArray("pkcs7.verify.pkcs7.verify.certs")
DO WHILE i < nCount_i
oJson:I := i
cIssuerCN := oJson:StringOf("pkcs7.verify.pkcs7.verify.certs[i].issuerCN")
cSerial := oJson:StringOf("pkcs7.verify.pkcs7.verify.certs[i].serial")
i := i + 1
ENDDO
oPdf:destroy()
oSigInfo:destroy()
oJson:destroy()
oUnauthAttrTimestampTokenTstInfoGenTime:destroy()
oSigningTime:destroy()
oAuthAttrSigningTimeUtctime:destroy()