Pascal (Lazarus/Delphi)
Pascal (Lazarus/Delphi)
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 Pascal (Lazarus/Delphi) Downloads
program ChilkatDemo;
// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.
{$IFDEF FPC}
{$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}
uses
{$IFDEF UNIX}
cthreads,
{$ENDIF}
SysUtils,
CkDllLoader,
Chilkat.DtObj,
Chilkat.Pdf,
Chilkat.JsonObject;
// ---------------------------------------------------------------------------
procedure RunDemo;
var
success: Boolean;
pdf: TPdf;
sigInfo: TJsonObject;
numSignatures: Integer;
validated: Boolean;
i: Integer;
json: TJsonObject;
unauthAttrTimestampTokenTstInfoGenTime: TDtObj;
signingTime: TDtObj;
authAttrSigningTimeUtctime: TDtObj;
intVal: Integer;
strVal: string;
issuerCN: string;
serial: string;
certSerialNumber: string;
certIssuerCN: string;
certDigestAlgOid: string;
certDigestAlgName: string;
contentType: string;
messageDigest: string;
signingAlgOid: string;
signingAlgName: string;
authAttr1_2_840_113583_1_1_8Der: string;
authAttrContentTypeName: string;
authAttrContentTypeOid: string;
authAttrMessageDigestName: string;
authAttrMessageDigestDigest: string;
unauthAttrTimestampTokenName: string;
unauthAttrTimestampTokenDer: string;
unauthAttrTimestampTokenTimestampSignatureVerified: Boolean;
unauthAttrTimestampTokenTstInfoTsaPolicyId: string;
unauthAttrTimestampTokenTstInfoMessageImprintHashAlg: string;
unauthAttrTimestampTokenTstInfoMessageImprintDigest: string;
unauthAttrTimestampTokenTstInfoMessageImprintDigestMatches: Boolean;
unauthAttrTimestampTokenTstInfoSerialNumber: string;
j: Integer;
count_j: Integer;
authAttrSigningTimeName: string;
authAttrSigningCertificateName: string;
authAttrSigningCertificateDer: string;
signatureDictionary_Contents: string;
signatureDictionary_Filter: string;
signatureDictionary_M: string;
signatureDictionary_Name: string;
signatureDictionary_Prop_Build_App_Name: string;
signatureDictionary_Prop_Build_App_R: Integer;
signatureDictionary_Prop_Build_App_REx: string;
signatureDictionary_Prop_Build_App_TrustedMode: Boolean;
signatureDictionary_Prop_Build_Filter_Date: string;
signatureDictionary_Prop_Build_Filter_Name: string;
signatureDictionary_Prop_Build_Filter_R: Integer;
signatureDictionary_Prop_Build_Filter_V: Integer;
signatureDictionary_Prop_Build_PubSec_Date: string;
signatureDictionary_Prop_Build_PubSec_NonEFontNoWarn: Boolean;
signatureDictionary_Prop_Build_PubSec_R: Integer;
signatureDictionary_SubFilter: string;
signatureDictionary_Type: string;
count_i: Integer;
begin
success := False;
// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.
pdf := TPdf.Create;
// Load a PDF that has cryptographic signatures to be validated
success := pdf.LoadFile('qa_data/pdf/sign_testing_1/helloSigned2.pdf');
if (success = False) then
begin
WriteLn(pdf.LastErrorText);
Exit;
end;
// Each time we verify a signature, information about the signature is written into
// sigInfo (replacing whatever sigInfo previously contained).
sigInfo := TJsonObject.Create;
sigInfo.EmitCompact := False;
// Iterate over each signature and validate each.
numSignatures := pdf.NumSignatures;
validated := False;
i := 0;
while i < numSignatures do
begin
validated := pdf.VerifySignature(i,sigInfo);
WriteLn('Signature ' + i + ' validated: ' + validated);
WriteLn(sigInfo.Emit());
i := i + 1;
end;
WriteLn('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.
json := TJsonObject.Create;
// 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 := TDtObj.Create;
signingTime := TDtObj.Create;
authAttrSigningTimeUtctime := TDtObj.Create;
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 do
begin
json.I := i;
intVal := json.IntOf('signatureDictionary./ByteRange[i]');
i := i + 1;
end;
i := 0;
count_i := json.SizeOfArray('signatureDictionary./Prop_Build./App./OS');
while i < count_i do
begin
json.I := i;
strVal := json.StringOf('signatureDictionary./Prop_Build./App./OS[i]');
i := i + 1;
end;
i := 0;
count_i := json.SizeOfArray('pkcs7.verify.certs');
while i < count_i do
begin
json.I := i;
issuerCN := json.StringOf('pkcs7.verify.certs[i].issuerCN');
serial := json.StringOf('pkcs7.verify.certs[i].serial');
i := i + 1;
end;
i := 0;
count_i := json.SizeOfArray('pkcs7.verify.digestAlgorithms');
while i < count_i do
begin
json.I := i;
strVal := json.StringOf('pkcs7.verify.digestAlgorithms[i]');
i := i + 1;
end;
i := 0;
count_i := json.SizeOfArray('pkcs7.verify.signerInfo');
while i < count_i do
begin
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 do
begin
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;
end;
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 do
begin
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;
end;
i := i + 1;
end;
i := 0;
count_i := json.SizeOfArray('pkcs7.verify.pkcs7.verify.certs');
while i < count_i do
begin
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;
end;
pdf.Free;
sigInfo.Free;
json.Free;
unauthAttrTimestampTokenTstInfoGenTime.Free;
signingTime.Free;
authAttrSigningTimeUtctime.Free;
end;
// ---------------------------------------------------------------------------
begin
try
RunDemo;
except
on E: Exception do
WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
end;
WriteLn;
{$IFDEF MSWINDOWS}
WriteLn('Press Enter to exit...');
ReadLn;
{$ENDIF}
end.