Tcl
Tcl
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 Tcl Downloads
load ./chilkat.dll
set success 0
# This example requires the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.
set pdf [new_CkPdf]
# Load a PDF that has cryptographic signatures to be validated
set success [CkPdf_LoadFile $pdf "qa_data/pdf/sign_testing_1/helloSigned2.pdf"]
if {$success == 0} then {
puts [CkPdf_lastErrorText $pdf]
delete_CkPdf $pdf
exit
}
# Each time we verify a signature, information about the signature is written into
# sigInfo (replacing whatever sigInfo previously contained).
set sigInfo [new_CkJsonObject]
CkJsonObject_put_EmitCompact $sigInfo 0
# Iterate over each signature and validate each.
set numSignatures [CkPdf_get_NumSignatures $pdf]
set validated 0
set i 0
while {$i < $numSignatures} {
set validated [CkPdf_VerifySignature $pdf $i $sigInfo]
puts "Signature $i validated: $validated"
puts [CkJsonObject_emit $sigInfo]
set i [expr $i + 1]
}
puts "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.
set json [new_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
set unauthAttrTimestampTokenTstInfoGenTime [new_CkDtObj]
set signingTime [new_CkDtObj]
set authAttrSigningTimeUtctime [new_CkDtObj]
set validated [CkJsonObject_BoolOf $json "validated"]
set signatureDictionary_Contents [CkJsonObject_stringOf $json "signatureDictionary./Contents"]
set signatureDictionary_Filter [CkJsonObject_stringOf $json "signatureDictionary./Filter"]
set signatureDictionary_M [CkJsonObject_stringOf $json "signatureDictionary./M"]
set signatureDictionary_Name [CkJsonObject_stringOf $json "signatureDictionary./Name"]
set signatureDictionary_Prop_Build_App_Name [CkJsonObject_stringOf $json "signatureDictionary./Prop_Build./App./Name"]
set signatureDictionary_Prop_Build_App_R [CkJsonObject_IntOf $json "signatureDictionary./Prop_Build./App./R"]
set signatureDictionary_Prop_Build_App_REx [CkJsonObject_stringOf $json "signatureDictionary./Prop_Build./App./REx"]
set signatureDictionary_Prop_Build_App_TrustedMode [CkJsonObject_BoolOf $json "signatureDictionary./Prop_Build./App./TrustedMode"]
set signatureDictionary_Prop_Build_Filter_Date [CkJsonObject_stringOf $json "signatureDictionary./Prop_Build./Filter./Date"]
set signatureDictionary_Prop_Build_Filter_Name [CkJsonObject_stringOf $json "signatureDictionary./Prop_Build./Filter./Name"]
set signatureDictionary_Prop_Build_Filter_R [CkJsonObject_IntOf $json "signatureDictionary./Prop_Build./Filter./R"]
set signatureDictionary_Prop_Build_Filter_V [CkJsonObject_IntOf $json "signatureDictionary./Prop_Build./Filter./V"]
set signatureDictionary_Prop_Build_PubSec_Date [CkJsonObject_stringOf $json "signatureDictionary./Prop_Build./PubSec./Date"]
set signatureDictionary_Prop_Build_PubSec_NonEFontNoWarn [CkJsonObject_BoolOf $json "signatureDictionary./Prop_Build./PubSec./NonEFontNoWarn"]
set signatureDictionary_Prop_Build_PubSec_R [CkJsonObject_IntOf $json "signatureDictionary./Prop_Build./PubSec./R"]
set signatureDictionary_SubFilter [CkJsonObject_stringOf $json "signatureDictionary./SubFilter"]
set signatureDictionary_Type [CkJsonObject_stringOf $json "signatureDictionary./Type"]
set i 0
set count_i [CkJsonObject_SizeOfArray $json "signatureDictionary./ByteRange"]
while {$i < $count_i} {
CkJsonObject_put_I $json $i
set intVal [CkJsonObject_IntOf $json "signatureDictionary./ByteRange[i]"]
set i [expr $i + 1]
}
set i 0
set count_i [CkJsonObject_SizeOfArray $json "signatureDictionary./Prop_Build./App./OS"]
while {$i < $count_i} {
CkJsonObject_put_I $json $i
set strVal [CkJsonObject_stringOf $json "signatureDictionary./Prop_Build./App./OS[i]"]
set i [expr $i + 1]
}
set i 0
set count_i [CkJsonObject_SizeOfArray $json "pkcs7.verify.certs"]
while {$i < $count_i} {
CkJsonObject_put_I $json $i
set issuerCN [CkJsonObject_stringOf $json "pkcs7.verify.certs[i].issuerCN"]
set serial [CkJsonObject_stringOf $json "pkcs7.verify.certs[i].serial"]
set i [expr $i + 1]
}
set i 0
set count_i [CkJsonObject_SizeOfArray $json "pkcs7.verify.digestAlgorithms"]
while {$i < $count_i} {
CkJsonObject_put_I $json $i
set strVal [CkJsonObject_stringOf $json "pkcs7.verify.digestAlgorithms[i]"]
set i [expr $i + 1]
}
set i 0
set count_i [CkJsonObject_SizeOfArray $json "pkcs7.verify.signerInfo"]
while {$i < $count_i} {
CkJsonObject_put_I $json $i
set certSerialNumber [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].cert.serialNumber"]
set certIssuerCN [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].cert.issuerCN"]
set certDigestAlgOid [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].cert.digestAlgOid"]
set certDigestAlgName [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].cert.digestAlgName"]
set contentType [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].contentType"]
set messageDigest [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].messageDigest"]
set signingAlgOid [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].signingAlgOid"]
set signingAlgName [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].signingAlgName"]
set authAttr1_2_840_113583_1_1_8Der [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113583.1.1.8\".der"]
set authAttrContentTypeName [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.3\".name"]
set authAttrContentTypeOid [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.3\".oid"]
set authAttrMessageDigestName [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.4\".name"]
set authAttrMessageDigestDigest [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.4\".digest"]
set unauthAttrTimestampTokenName [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].unauthAttr.\"1.2.840.113549.1.9.16.2.14\".name"]
set unauthAttrTimestampTokenDer [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].unauthAttr.\"1.2.840.113549.1.9.16.2.14\".der"]
set unauthAttrTimestampTokenTimestampSignatureVerified [CkJsonObject_BoolOf $json "pkcs7.verify.signerInfo[i].unauthAttr.\"1.2.840.113549.1.9.16.2.14\".timestampSignatureVerified"]
set unauthAttrTimestampTokenTstInfoTsaPolicyId [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].unauthAttr.\"1.2.840.113549.1.9.16.2.14\".tstInfo.tsaPolicyId"]
set unauthAttrTimestampTokenTstInfoMessageImprintHashAlg [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].unauthAttr.\"1.2.840.113549.1.9.16.2.14\".tstInfo.messageImprint.hashAlg"]
set unauthAttrTimestampTokenTstInfoMessageImprintDigest [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].unauthAttr.\"1.2.840.113549.1.9.16.2.14\".tstInfo.messageImprint.digest"]
set unauthAttrTimestampTokenTstInfoMessageImprintDigestMatches [CkJsonObject_BoolOf $json "pkcs7.verify.signerInfo[i].unauthAttr.\"1.2.840.113549.1.9.16.2.14\".tstInfo.messageImprint.digestMatches"]
set unauthAttrTimestampTokenTstInfoSerialNumber [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].unauthAttr.\"1.2.840.113549.1.9.16.2.14\".tstInfo.serialNumber"]
CkJsonObject_DtOf $json "pkcs7.verify.signerInfo[i].unauthAttr.\"1.2.840.113549.1.9.16.2.14\".tstInfo.genTime" 0 $unauthAttrTimestampTokenTstInfoGenTime
set j 0
set count_j [CkJsonObject_SizeOfArray $json "pkcs7.verify.signerInfo[i].unauthAttr.\"1.2.840.113549.1.9.16.2.14\".verify.digestAlgorithms"]
while {$j < $count_j} {
CkJsonObject_put_J $json $j
set strVal [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].unauthAttr.\"1.2.840.113549.1.9.16.2.14\".verify.digestAlgorithms[j]"]
set j [expr $j + 1]
}
set j 0
set count_j [CkJsonObject_SizeOfArray $json "pkcs7.verify.signerInfo[i].unauthAttr.\"1.2.840.113549.1.9.16.2.14\".verify.signerInfo"]
while {$j < $count_j} {
CkJsonObject_put_J $json $j
set certSerialNumber [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].unauthAttr.\"1.2.840.113549.1.9.16.2.14\".verify.signerInfo[j].cert.serialNumber"]
set certIssuerCN [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].unauthAttr.\"1.2.840.113549.1.9.16.2.14\".verify.signerInfo[j].cert.issuerCN"]
set certDigestAlgOid [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].unauthAttr.\"1.2.840.113549.1.9.16.2.14\".verify.signerInfo[j].cert.digestAlgOid"]
set certDigestAlgName [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].unauthAttr.\"1.2.840.113549.1.9.16.2.14\".verify.signerInfo[j].cert.digestAlgName"]
set contentType [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].unauthAttr.\"1.2.840.113549.1.9.16.2.14\".verify.signerInfo[j].contentType"]
CkJsonObject_DtOf $json "pkcs7.verify.signerInfo[i].unauthAttr.\"1.2.840.113549.1.9.16.2.14\".verify.signerInfo[j].signingTime" 0 $signingTime
set messageDigest [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].unauthAttr.\"1.2.840.113549.1.9.16.2.14\".verify.signerInfo[j].messageDigest"]
set signingAlgOid [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].unauthAttr.\"1.2.840.113549.1.9.16.2.14\".verify.signerInfo[j].signingAlgOid"]
set signingAlgName [CkJsonObject_stringOf $json "pkcs7.verify.signerInfo[i].unauthAttr.\"1.2.840.113549.1.9.16.2.14\".verify.signerInfo[j].signingAlgName"]
set authAttrContentTypeName [CkJsonObject_stringOf $json "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"]
set authAttrContentTypeOid [CkJsonObject_stringOf $json "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"]
set authAttrSigningTimeName [CkJsonObject_stringOf $json "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"]
CkJsonObject_DtOf $json "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
set authAttrSigningCertificateName [CkJsonObject_stringOf $json "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"]
set authAttrSigningCertificateDer [CkJsonObject_stringOf $json "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"]
set authAttrMessageDigestName [CkJsonObject_stringOf $json "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"]
set authAttrMessageDigestDigest [CkJsonObject_stringOf $json "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"]
set j [expr $j + 1]
}
set i [expr $i + 1]
}
set i 0
set count_i [CkJsonObject_SizeOfArray $json "pkcs7.verify.pkcs7.verify.certs"]
while {$i < $count_i} {
CkJsonObject_put_I $json $i
set issuerCN [CkJsonObject_stringOf $json "pkcs7.verify.pkcs7.verify.certs[i].issuerCN"]
set serial [CkJsonObject_stringOf $json "pkcs7.verify.pkcs7.verify.certs[i].serial"]
set i [expr $i + 1]
}
delete_CkPdf $pdf
delete_CkJsonObject $sigInfo
delete_CkJsonObject $json
delete_CkDtObj $unauthAttrTimestampTokenTstInfoGenTime
delete_CkDtObj $signingTime
delete_CkDtObj $authAttrSigningTimeUtctime