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Pascal (Lazarus/Delphi)

Validate JWS with Multiple Signatures using the General JSON Serialization Format

See more JSON Web Signatures (JWS) Examples

Validates and recovers data and headers from a JSON Web Signature (JWS) containing 3 signatures.

Note: Chilkat supports all of the following JWS algorithms:

   +--------------+-------------------------------+--------------------+
   | "alg" Param  | Digital Signature or MAC      | Implementation     |
   | Value        | Algorithm                     | Requirements       |
   +--------------+-------------------------------+--------------------+
   | HS256        | HMAC using SHA-256            | Required           |
   | HS384        | HMAC using SHA-384            | Optional           |
   | HS512        | HMAC using SHA-512            | Optional           |
   | RS256        | RSASSA-PKCS1-v1_5 using       | Recommended        |
   |              | SHA-256                       |                    |
   | RS384        | RSASSA-PKCS1-v1_5 using       | Optional           |
   |              | SHA-384                       |                    |
   | RS512        | RSASSA-PKCS1-v1_5 using       | Optional           |
   |              | SHA-512                       |                    |
   | ES256        | ECDSA using P-256 and SHA-256 | Recommended+       |
   | ES384        | ECDSA using P-384 and SHA-384 | Optional           |
   | ES512        | ECDSA using P-521 and SHA-512 | Optional           |
   | PS256        | RSASSA-PSS using SHA-256 and  | Optional           |
   |              | MGF1 with SHA-256             |                    |
   | PS384        | RSASSA-PSS using SHA-384 and  | Optional           |
   |              | MGF1 with SHA-384             |                    |
   | PS512        | RSASSA-PSS using SHA-512 and  | Optional           |
   |              | MGF1 with SHA-512             |                    |
   +--------------+-------------------------------+--------------------+

Chilkat Pascal (Lazarus/Delphi) Downloads

Pascal (Lazarus/Delphi)
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.StringBuilder,
  Chilkat.Jws,
  Chilkat.PublicKey,
  Chilkat.JsonObject;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  sbRsaJwk: TStringBuilder;
  rsaKey: TPublicKey;
  sbEccJwk: TStringBuilder;
  eccKey: TPublicKey;
  hmacKey: string;
  sbJws: TStringBuilder;
  jws: TJws;
  sbKeyId: TStringBuilder;
  bCaseSensitive: Boolean;
  protHeader: TJsonObject;
  numSignatures: Integer;
  i: Integer;
  v: Integer;

begin
  success := False;

  //  This requires the Chilkat API to have been previously unlocked.
  //  See Global Unlock Sample for sample code.

  //  First, prepare the public keys that will be needed for each signature.

  //  ---------------------------------------------------
  //  Use the following RSA key loaded from JWK format.
  sbRsaJwk := TStringBuilder.Create;
  sbRsaJwk.Append('{"kty":"RSA",');
  sbRsaJwk.Append('"n":"ofgWCuLjybRlzo0tZWJjNiuSfb4p4fAkd_wWJcyQoTbji9k0l8W26mPddx');
  sbRsaJwk.Append('HmfHQp-Vaw-4qPCJrcS2mJPMEzP1Pt0Bm4d4QlL-yRT-SFd2lZS-pCgNMs');
  sbRsaJwk.Append('D1W_YpRPEwOWvG6b32690r2jZ47soMZo9wGzjb_7OMg0LOL-bSf63kpaSH');
  sbRsaJwk.Append('SXndS5z5rexMdbBYUsLA9e-KXBdQOS-UTo7WTBEMa2R2CapHg665xsmtdV');
  sbRsaJwk.Append('MTBQY4uDZlxvb3qCo5ZwKh9kG4LT6_I5IhlJH7aGhyxXFvUK-DWNmoudF8');
  sbRsaJwk.Append('NAco9_h9iaGNj8q2ethFkMLs91kzk2PAcDTW9gb54h4FRWyuXpoQ",');
  sbRsaJwk.Append('"e":"AQAB"');
  sbRsaJwk.Append('}');

  rsaKey := TPublicKey.Create;
  success := rsaKey.LoadFromString(sbRsaJwk.GetAsString());
  if (success = False) then
    begin
      WriteLn(rsaKey.LastErrorText);
      Exit;
    end;

  //  ---------------------------------------------------
  //  Use the following ECC public key loaded from JWK format.
  sbEccJwk := TStringBuilder.Create;
  sbEccJwk.Append('{"kty":"EC",');
  sbEccJwk.Append('"crv":"P-256",');
  sbEccJwk.Append('"x":"f83OJ3D2xF1Bg8vub9tLe1gHMzV76e8Tus9uPHvRVEU",');
  sbEccJwk.Append('"y":"x_FEzRu9m36HLN_tue659LNpXW6pCyStikYjKIWI5a0"');
  sbEccJwk.Append('}');

  eccKey := TPublicKey.Create;
  success := eccKey.LoadFromString(sbEccJwk.GetAsString());
  if (success = False) then
    begin
      WriteLn(eccKey.LastErrorText);
      Exit;
    end;

  //  ---------------------------------------------------
  //  The HMAC key (in base64url format)
  hmacKey := 'AyM1SysPpbyDfgZld3umj1qzKObwVMkoqQ-EstJQLr_T-1qS0gZH75aKtMN3Yj0iPS4hcgUuTwjAzZr1Z9CAow';

  //  The code below will verify each of the signatures in this JWS:

  //  { 
  //    "payload": "SW4gb3VyIHZpbGxhZ2UsIGZvbGtzIHNheSBHb2QgY3J1bWJsZXMgdXAgdGhlIG9sZCBtb29uIGludG8gc3RhcnMu",
  //    "signatures": [
  //      { 
  //        "protected": "eyJhbGciOiJSUzI1NiIsImtpZCI6Im15UnNhS2V5In0",
  //        "signature": "IPMQ02niTQDwLzsRZSCaEm9VEyAX_AVe3HWjniNt9kW-a8d6ZVbd2k6jGae8s1yIh0cgxDnXQ6-p6_sBI0cnMO0xpuJANhh2vFtNJl5lisad94-H3mB3lSfafRqxeYp5D8bh39BPv7y3PrUNVMQdKEJp_D5oJ0ROPTIYx3EG8eJQOx1HO0KqhcUo401XR6KSsIyFm5joBLNKTVzxZUTT1RRZZtwTdeZkbGevugIOX_9gHAtARpV6WaFA4Vvjnq8X9wPgqjWNCQRupadhTPz0JAsa-wy5vXQjsFlXAn43mDPpMfna5Ab3F5pS4yDwkbX6nRn7XBxH1SnnNJRFholQZw"
  //      },
  //      { 
  //        "protected": "eyJhbGciOiJFUzI1NiIsImtpZCI6Im15RWNLZXkifQ",
  //        "signature": "1OQtaT3pgZmkDxvlfghvxL_8kX16WIen6u1MadEq1pA4qytA0--_EwZDNk00GDPWFpoJtKznibMZzLOg_UhHIw"
  //      },
  //      { 
  //        "protected": "eyJhbGciOiJIUzI1NiIsImtpZCI6Im15TWFjS2V5In0",
  //        "signature": "YY8yVjmJJfy7YJOn3uUydG8WCY2PEuCvOLil5Ks5lnw"
  //      }
  //    ]
  //  }

  sbJws := TStringBuilder.Create;
  sbJws.Append('{ ');
  sbJws.Append('  "payload": "SW4gb3VyIHZpbGxhZ2UsIGZvbGtzIHNheSBHb2QgY3J1bWJsZXMgdXAgdGhlIG9sZCBtb29uIGludG8gc3RhcnMu",');
  sbJws.Append('  "signatures": [');
  sbJws.Append('    { ');
  sbJws.Append('      "protected": "eyJhbGciOiJSUzI1NiIsImtpZCI6Im15UnNhS2V5In0",');
  sbJws.Append('      "signature": "IPMQ02niTQDwLzsRZSCaEm9VEyAX_AVe3HWjniNt9kW-a8d6ZVbd2k6jGae8s1yIh0cgxDnXQ6-p6_sBI0cnMO0xpuJANhh2vFtNJl5lisad94-H3mB3lSfafRqxeYp5D8bh39BPv7y3PrUNVMQdKEJp_D5oJ0ROPTIYx3EG8eJQOx1HO0KqhcUo401XR6KSsIyFm5joBLNKTVzxZUTT1RRZZtwTdeZkbGevugIOX_9gHAtARpV6WaFA4Vvjnq8X9wPgqjWNCQRupadhTPz0JAsa-wy5vXQjsFlXAn43mDPpMfna5Ab3F5pS4yDwkbX6nRn7XBxH1SnnNJRFholQZw"');
  sbJws.Append('    },');
  sbJws.Append('    { ');
  sbJws.Append('      "protected": "eyJhbGciOiJFUzI1NiIsImtpZCI6Im15RWNLZXkifQ",');
  sbJws.Append('      "signature": "1OQtaT3pgZmkDxvlfghvxL_8kX16WIen6u1MadEq1pA4qytA0--_EwZDNk00GDPWFpoJtKznibMZzLOg_UhHIw"');
  sbJws.Append('    },');
  sbJws.Append('    { ');
  sbJws.Append('      "protected": "eyJhbGciOiJIUzI1NiIsImtpZCI6Im15TWFjS2V5In0",');
  sbJws.Append('      "signature": "YY8yVjmJJfy7YJOn3uUydG8WCY2PEuCvOLil5Ks5lnw"');
  sbJws.Append('    }');
  sbJws.Append('  ]');
  sbJws.Append('}');

  jws := TJws.Create;

  success := jws.LoadJwsSb(sbJws);
  if (success = False) then
    begin
      WriteLn(jws.LastErrorText);
      Exit;
    end;

  //  The payload is easily accessible:
  WriteLn('Payload: ' + jws.GetPayload('utf-8'));

  sbKeyId := TStringBuilder.Create;
  bCaseSensitive := False;

  protHeader := TJsonObject.Create;
  numSignatures := jws.NumSignatures;
  i := 0;
  while i < numSignatures do
    begin
      success := jws.GetProtectedH(i,protHeader);
      if (success = False) then
        begin
          WriteLn(jws.LastErrorText);
          Exit;
        end;

      WriteLn('--------------------------');
      WriteLn(i + ': ');

      //  Get the protected header.
      protHeader.EmitCompact := False;
      WriteLn(protHeader.Emit());

      //  Get the key ID ("kid") member.

      //  Note: In this example, the "kid" values are contained in the protected headers.
      //  They could've just as easily been located in unprotected headers.  In that case,
      //  we would've called GetUnprotectedH instead of GetProtectedH(i).

      sbKeyId.Clear();
      sbKeyId.Append(protHeader.StringOf('kid'));

      //  Set the key based on key ID.
      if (sbKeyId.ContentsEqual('myRsaKey',bCaseSensitive) = True) then
        begin
          jws.SetPublicKey(i,rsaKey);
        end;
      if (sbKeyId.ContentsEqual('myEcKey',bCaseSensitive) = True) then
        begin
          jws.SetPublicKey(i,eccKey);
        end;
      if (sbKeyId.ContentsEqual('myMacKey',bCaseSensitive) = True) then
        begin
          jws.SetMacKey(i,hmacKey,'base64url');
        end;

      //  Validate this signature.
      v := jws.Validate(i);
      if (v < 0) then
        begin
          //  Perhaps Chilkat was not unlocked or the trial expired..
          WriteLn('Validate failed for some other reason.');
          WriteLn(jws.LastErrorText);
        end
      else
        begin
          if (v = 0) then
            begin
              WriteLn('Invalid signature.  The key was incorrect, the JWS was invalid, or both.');
            end
          else
            begin
              WriteLn('Signature validated.');
            end;
        end;
      i := i + 1;
    end;

  //  The output of this program is:

  //  	Payload: In our village, folks say God crumbles up the old moon into stars.
  //  	--------------------------
  //  	0: 
  //  	{
  //  	  "alg": "RS256",
  //  	  "kid": "myRsaKey"
  //  	}
  //  
  //  	Signature validated.
  //  	--------------------------
  //  	1: 
  //  	{
  //  	  "alg": "ES256",
  //  	  "kid": "myEcKey"
  //  	}
  //  
  //  	Signature validated.
  //  	--------------------------
  //  	2: 
  //  	{
  //  	  "alg": "HS256",
  //  	  "kid": "myMacKey"
  //  	}
  //  
  //  	Signature validated.


  sbRsaJwk.Free;
  rsaKey.Free;
  sbEccJwk.Free;
  eccKey.Free;
  sbJws.Free;
  jws.Free;
  sbKeyId.Free;
  protHeader.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.