Classic ASP
Classic ASP
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 Classic ASP Downloads
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<%
success = 0
' This example requires the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.
set pdf = Server.CreateObject("Chilkat.Pdf")
' Load a PDF that has cryptographic signatures to be validated
success = pdf.LoadFile("qa_data/pdf/sign_testing_1/helloSigned2.pdf")
If (success = 0) Then
Response.Write "<pre>" & Server.HTMLEncode( pdf.LastErrorText) & "</pre>"
Response.End
End If
' Each time we verify a signature, information about the signature is written into
' sigInfo (replacing whatever sigInfo previously contained).
set sigInfo = Server.CreateObject("Chilkat.JsonObject")
sigInfo.EmitCompact = 0
' Iterate over each signature and validate each.
numSignatures = pdf.NumSignatures
validated = 0
i = 0
Do While i < numSignatures
validated = pdf.VerifySignature(i,sigInfo)
Response.Write "<pre>" & Server.HTMLEncode( "Signature " & i & " validated: " & validated) & "</pre>"
Response.Write "<pre>" & Server.HTMLEncode( sigInfo.Emit()) & "</pre>"
i = i + 1
Loop
Response.Write "<pre>" & Server.HTMLEncode( "Finished.") & "</pre>"
' 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.
set json = Server.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
set unauthAttrTimestampTokenTstInfoGenTime = Server.CreateObject("Chilkat.DtObj")
set signingTime = Server.CreateObject("Chilkat.DtObj")
set authAttrSigningTimeUtctime = Server.CreateObject("Chilkat.DtObj")
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")
Do While i < count_i
json.I = i
intVal = json.IntOf("signatureDictionary./ByteRange[i]")
i = i + 1
Loop
i = 0
count_i = json.SizeOfArray("signatureDictionary./Prop_Build./App./OS")
Do While i < count_i
json.I = i
strVal = json.StringOf("signatureDictionary./Prop_Build./App./OS[i]")
i = i + 1
Loop
i = 0
count_i = json.SizeOfArray("pkcs7.verify.certs")
Do 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
Loop
i = 0
count_i = json.SizeOfArray("pkcs7.verify.digestAlgorithms")
Do While i < count_i
json.I = i
strVal = json.StringOf("pkcs7.verify.digestAlgorithms[i]")
i = i + 1
Loop
i = 0
count_i = json.SizeOfArray("pkcs7.verify.signerInfo")
Do 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")
success = 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")
Do 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
Loop
j = 0
count_j = json.SizeOfArray("pkcs7.verify.signerInfo[i].unauthAttr.""1.2.840.113549.1.9.16.2.14"".verify.signerInfo")
Do 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")
success = 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")
success = 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
Loop
i = i + 1
Loop
i = 0
count_i = json.SizeOfArray("pkcs7.verify.pkcs7.verify.certs")
Do 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
Loop
%>
</body>
</html>