Delphi DLL
Delphi DLL
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 Delphi DLL Downloads
uses
Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, DtObj, Pdf, JsonObject;
...
procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
pdf: HCkPdf;
sigInfo: HCkJsonObject;
numSignatures: Integer;
validated: Boolean;
i: Integer;
json: HCkJsonObject;
unauthAttrTimestampTokenTstInfoGenTime: HCkDtObj;
signingTime: HCkDtObj;
authAttrSigningTimeUtctime: HCkDtObj;
intVal: Integer;
strVal: PWideChar;
issuerCN: PWideChar;
serial: PWideChar;
certSerialNumber: PWideChar;
certIssuerCN: PWideChar;
certDigestAlgOid: PWideChar;
certDigestAlgName: PWideChar;
contentType: PWideChar;
messageDigest: PWideChar;
signingAlgOid: PWideChar;
signingAlgName: PWideChar;
authAttr1_2_840_113583_1_1_8Der: PWideChar;
authAttrContentTypeName: PWideChar;
authAttrContentTypeOid: PWideChar;
authAttrMessageDigestName: PWideChar;
authAttrMessageDigestDigest: PWideChar;
unauthAttrTimestampTokenName: PWideChar;
unauthAttrTimestampTokenDer: PWideChar;
unauthAttrTimestampTokenTimestampSignatureVerified: Boolean;
unauthAttrTimestampTokenTstInfoTsaPolicyId: PWideChar;
unauthAttrTimestampTokenTstInfoMessageImprintHashAlg: PWideChar;
unauthAttrTimestampTokenTstInfoMessageImprintDigest: PWideChar;
unauthAttrTimestampTokenTstInfoMessageImprintDigestMatches: Boolean;
unauthAttrTimestampTokenTstInfoSerialNumber: PWideChar;
j: Integer;
count_j: Integer;
authAttrSigningTimeName: PWideChar;
authAttrSigningCertificateName: PWideChar;
authAttrSigningCertificateDer: PWideChar;
signatureDictionary_Contents: PWideChar;
signatureDictionary_Filter: PWideChar;
signatureDictionary_M: PWideChar;
signatureDictionary_Name: PWideChar;
signatureDictionary_Prop_Build_App_Name: PWideChar;
signatureDictionary_Prop_Build_App_R: Integer;
signatureDictionary_Prop_Build_App_REx: PWideChar;
signatureDictionary_Prop_Build_App_TrustedMode: Boolean;
signatureDictionary_Prop_Build_Filter_Date: PWideChar;
signatureDictionary_Prop_Build_Filter_Name: PWideChar;
signatureDictionary_Prop_Build_Filter_R: Integer;
signatureDictionary_Prop_Build_Filter_V: Integer;
signatureDictionary_Prop_Build_PubSec_Date: PWideChar;
signatureDictionary_Prop_Build_PubSec_NonEFontNoWarn: Boolean;
signatureDictionary_Prop_Build_PubSec_R: Integer;
signatureDictionary_SubFilter: PWideChar;
signatureDictionary_Type: PWideChar;
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 := CkPdf_Create();
// Load a PDF that has cryptographic signatures to be validated
success := CkPdf_LoadFile(pdf,'qa_data/pdf/sign_testing_1/helloSigned2.pdf');
if (success = False) then
begin
Memo1.Lines.Add(CkPdf__lastErrorText(pdf));
Exit;
end;
// Each time we verify a signature, information about the signature is written into
// sigInfo (replacing whatever sigInfo previously contained).
sigInfo := CkJsonObject_Create();
CkJsonObject_putEmitCompact(sigInfo,False);
// Iterate over each signature and validate each.
numSignatures := CkPdf_getNumSignatures(pdf);
validated := False;
i := 0;
while i < numSignatures do
begin
validated := CkPdf_VerifySignature(pdf,i,sigInfo);
Memo1.Lines.Add('Signature ' + IntToStr(i) + ' validated: ' + IntToStr(Ord(validated)));
Memo1.Lines.Add(CkJsonObject__emit(sigInfo));
i := i + 1;
end;
Memo1.Lines.Add('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 := CkJsonObject_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 := CkDtObj_Create();
signingTime := CkDtObj_Create();
authAttrSigningTimeUtctime := CkDtObj_Create();
validated := CkJsonObject_BoolOf(json,'validated');
signatureDictionary_Contents := CkJsonObject__stringOf(json,'signatureDictionary./Contents');
signatureDictionary_Filter := CkJsonObject__stringOf(json,'signatureDictionary./Filter');
signatureDictionary_M := CkJsonObject__stringOf(json,'signatureDictionary./M');
signatureDictionary_Name := CkJsonObject__stringOf(json,'signatureDictionary./Name');
signatureDictionary_Prop_Build_App_Name := CkJsonObject__stringOf(json,'signatureDictionary./Prop_Build./App./Name');
signatureDictionary_Prop_Build_App_R := CkJsonObject_IntOf(json,'signatureDictionary./Prop_Build./App./R');
signatureDictionary_Prop_Build_App_REx := CkJsonObject__stringOf(json,'signatureDictionary./Prop_Build./App./REx');
signatureDictionary_Prop_Build_App_TrustedMode := CkJsonObject_BoolOf(json,'signatureDictionary./Prop_Build./App./TrustedMode');
signatureDictionary_Prop_Build_Filter_Date := CkJsonObject__stringOf(json,'signatureDictionary./Prop_Build./Filter./Date');
signatureDictionary_Prop_Build_Filter_Name := CkJsonObject__stringOf(json,'signatureDictionary./Prop_Build./Filter./Name');
signatureDictionary_Prop_Build_Filter_R := CkJsonObject_IntOf(json,'signatureDictionary./Prop_Build./Filter./R');
signatureDictionary_Prop_Build_Filter_V := CkJsonObject_IntOf(json,'signatureDictionary./Prop_Build./Filter./V');
signatureDictionary_Prop_Build_PubSec_Date := CkJsonObject__stringOf(json,'signatureDictionary./Prop_Build./PubSec./Date');
signatureDictionary_Prop_Build_PubSec_NonEFontNoWarn := CkJsonObject_BoolOf(json,'signatureDictionary./Prop_Build./PubSec./NonEFontNoWarn');
signatureDictionary_Prop_Build_PubSec_R := CkJsonObject_IntOf(json,'signatureDictionary./Prop_Build./PubSec./R');
signatureDictionary_SubFilter := CkJsonObject__stringOf(json,'signatureDictionary./SubFilter');
signatureDictionary_Type := CkJsonObject__stringOf(json,'signatureDictionary./Type');
i := 0;
count_i := CkJsonObject_SizeOfArray(json,'signatureDictionary./ByteRange');
while i < count_i do
begin
CkJsonObject_putI(json,i);
intVal := CkJsonObject_IntOf(json,'signatureDictionary./ByteRange[i]');
i := i + 1;
end;
i := 0;
count_i := CkJsonObject_SizeOfArray(json,'signatureDictionary./Prop_Build./App./OS');
while i < count_i do
begin
CkJsonObject_putI(json,i);
strVal := CkJsonObject__stringOf(json,'signatureDictionary./Prop_Build./App./OS[i]');
i := i + 1;
end;
i := 0;
count_i := CkJsonObject_SizeOfArray(json,'pkcs7.verify.certs');
while i < count_i do
begin
CkJsonObject_putI(json,i);
issuerCN := CkJsonObject__stringOf(json,'pkcs7.verify.certs[i].issuerCN');
serial := CkJsonObject__stringOf(json,'pkcs7.verify.certs[i].serial');
i := i + 1;
end;
i := 0;
count_i := CkJsonObject_SizeOfArray(json,'pkcs7.verify.digestAlgorithms');
while i < count_i do
begin
CkJsonObject_putI(json,i);
strVal := CkJsonObject__stringOf(json,'pkcs7.verify.digestAlgorithms[i]');
i := i + 1;
end;
i := 0;
count_i := CkJsonObject_SizeOfArray(json,'pkcs7.verify.signerInfo');
while i < count_i do
begin
CkJsonObject_putI(json,i);
certSerialNumber := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].cert.serialNumber');
certIssuerCN := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].cert.issuerCN');
certDigestAlgOid := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].cert.digestAlgOid');
certDigestAlgName := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].cert.digestAlgName');
contentType := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].contentType');
messageDigest := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].messageDigest');
signingAlgOid := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].signingAlgOid');
signingAlgName := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].signingAlgName');
authAttr1_2_840_113583_1_1_8Der := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].authAttr."1.2.840.113583.1.1.8".der');
authAttrContentTypeName := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].authAttr."1.2.840.113549.1.9.3".name');
authAttrContentTypeOid := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].authAttr."1.2.840.113549.1.9.3".oid');
authAttrMessageDigestName := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].authAttr."1.2.840.113549.1.9.4".name');
authAttrMessageDigestDigest := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].authAttr."1.2.840.113549.1.9.4".digest');
unauthAttrTimestampTokenName := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".name');
unauthAttrTimestampTokenDer := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".der');
unauthAttrTimestampTokenTimestampSignatureVerified := CkJsonObject_BoolOf(json,'pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".timestampSignatureVerified');
unauthAttrTimestampTokenTstInfoTsaPolicyId := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".tstInfo.tsaPolicyId');
unauthAttrTimestampTokenTstInfoMessageImprintHashAlg := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".tstInfo.messageImprint.hashAlg');
unauthAttrTimestampTokenTstInfoMessageImprintDigest := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".tstInfo.messageImprint.digest');
unauthAttrTimestampTokenTstInfoMessageImprintDigestMatches := CkJsonObject_BoolOf(json,'pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".tstInfo.messageImprint.digestMatches');
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',False,unauthAttrTimestampTokenTstInfoGenTime);
j := 0;
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 do
begin
CkJsonObject_putJ(json,j);
strVal := CkJsonObject__stringOf(json,'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 := CkJsonObject_SizeOfArray(json,'pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo');
while j < count_j do
begin
CkJsonObject_putJ(json,j);
certSerialNumber := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].cert.serialNumber');
certIssuerCN := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].cert.issuerCN');
certDigestAlgOid := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].cert.digestAlgOid');
certDigestAlgName := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].cert.digestAlgName');
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',False,signingTime);
messageDigest := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].messageDigest');
signingAlgOid := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].signingAlgOid');
signingAlgName := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].unauthAttr."1.2.840.113549.1.9.16.2.14".verify.signerInfo[j].signingAlgName');
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');
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');
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',False,authAttrSigningTimeUtctime);
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');
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');
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');
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');
j := j + 1;
end;
i := i + 1;
end;
i := 0;
count_i := CkJsonObject_SizeOfArray(json,'pkcs7.verify.pkcs7.verify.certs');
while i < count_i do
begin
CkJsonObject_putI(json,i);
issuerCN := CkJsonObject__stringOf(json,'pkcs7.verify.pkcs7.verify.certs[i].issuerCN');
serial := CkJsonObject__stringOf(json,'pkcs7.verify.pkcs7.verify.certs[i].serial');
i := i + 1;
end;
CkPdf_Dispose(pdf);
CkJsonObject_Dispose(sigInfo);
CkJsonObject_Dispose(json);
CkDtObj_Dispose(unauthAttrTimestampTokenTstInfoGenTime);
CkDtObj_Dispose(signingTime);
CkDtObj_Dispose(authAttrSigningTimeUtctime);
end;