(Delphi DLL) JWS Using RSASSA-PSS using SHA-256 and MGF1 with SHA-256

Creates and validates a JSON Web Signature (JWS) using RSASSA-PSS using SHA-256 and MGF1 with SHA-256.

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             |                    |
   +--------------+-------------------------------+--------------------+

Note: This example requires Chilkat v9.5.0.66 or greater.

Chilkat for Delphi Downloads Chilkat non-ActiveX DLL for Delphi Chilkat ActiveX DLL for Delphi * The examples here use the non-ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, StringBuilder, PrivateKey, Jws, PublicKey, JsonObject;

...

procedure TForm1.Button1Click(Sender: TObject);
var
sbJwk: HCkStringBuilder;
rsaKey: HCkPrivateKey;
success: Boolean;
jwsProtHdr: HCkJsonObject;
jws: HCkJws;
signatureIndex: Integer;
bIncludeBom: Boolean;
payloadStr: PWideChar;
jwsCompact: PWideChar;
jws2: HCkJws;
rsaPubKey: HCkPublicKey;
v: Integer;
joseHeader: HCkJsonObject;

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

// Note: This example requires Chilkat v9.5.0.66 or greater.

// Use the following RSA key loaded from JWK format.
sbJwk := CkStringBuilder_Create();
CkStringBuilder_Append(sbJwk,'{"kty":"RSA",');
CkStringBuilder_Append(sbJwk,'"n":"ofgWCuLjybRlzo0tZWJjNiuSfb4p4fAkd_wWJcyQoTbji9k0l8W26mPddx');
CkStringBuilder_Append(sbJwk,'HmfHQp-Vaw-4qPCJrcS2mJPMEzP1Pt0Bm4d4QlL-yRT-SFd2lZS-pCgNMs');
CkStringBuilder_Append(sbJwk,'D1W_YpRPEwOWvG6b32690r2jZ47soMZo9wGzjb_7OMg0LOL-bSf63kpaSH');
CkStringBuilder_Append(sbJwk,'SXndS5z5rexMdbBYUsLA9e-KXBdQOS-UTo7WTBEMa2R2CapHg665xsmtdV');
CkStringBuilder_Append(sbJwk,'MTBQY4uDZlxvb3qCo5ZwKh9kG4LT6_I5IhlJH7aGhyxXFvUK-DWNmoudF8');
CkStringBuilder_Append(sbJwk,'NAco9_h9iaGNj8q2ethFkMLs91kzk2PAcDTW9gb54h4FRWyuXpoQ",');
CkStringBuilder_Append(sbJwk,'"e":"AQAB",');
CkStringBuilder_Append(sbJwk,'"d":"Eq5xpGnNCivDflJsRQBXHx1hdR1k6Ulwe2JZD50LpXyWPEAeP88vLNO97I');
CkStringBuilder_Append(sbJwk,'jlA7_GQ5sLKMgvfTeXZx9SE-7YwVol2NXOoAJe46sui395IW_GO-pWJ1O0');
CkStringBuilder_Append(sbJwk,'BkTGoVEn2bKVRUCgu-GjBVaYLU6f3l9kJfFNS3E0QbVdxzubSu3Mkqzjkn');
CkStringBuilder_Append(sbJwk,'439X0M_V51gfpRLI9JYanrC4D4qAdGcopV_0ZHHzQlBjudU2QvXt4ehNYT');
CkStringBuilder_Append(sbJwk,'CBr6XCLQUShb1juUO1ZdiYoFaFQT5Tw8bGUl_x_jTj3ccPDVZFD9pIuhLh');
CkStringBuilder_Append(sbJwk,'BOneufuBiB4cS98l2SR_RQyGWSeWjnczT0QU91p1DhOVRuOopznQ",');
CkStringBuilder_Append(sbJwk,'"p":"4BzEEOtIpmVdVEZNCqS7baC4crd0pqnRH_5IB3jw3bcxGn6QLvnEtfdUdi');
CkStringBuilder_Append(sbJwk,'YrqBdss1l58BQ3KhooKeQTa9AB0Hw_Py5PJdTJNPY8cQn7ouZ2KKDcmnPG');
CkStringBuilder_Append(sbJwk,'BY5t7yLc1QlQ5xHdwW1VhvKn-nXqhJTBgIPgtldC-KDV5z-y2XDwGUc",');
CkStringBuilder_Append(sbJwk,'"q":"uQPEfgmVtjL0Uyyx88GZFF1fOunH3-7cepKmtH4pxhtCoHqpWmT8YAmZxa');
CkStringBuilder_Append(sbJwk,'ewHgHAjLYsp1ZSe7zFYHj7C6ul7TjeLQeZD_YwD66t62wDmpe_HlB-TnBA');
CkStringBuilder_Append(sbJwk,'-njbglfIsRLtXlnDzQkv5dTltRJ11BKBBypeeF6689rjcJIDEz9RWdc",');
CkStringBuilder_Append(sbJwk,'"dp":"BwKfV3Akq5_MFZDFZCnW-wzl-CCo83WoZvnLQwCTeDv8uzluRSnm71I3Q');
CkStringBuilder_Append(sbJwk,'CLdhrqE2e9YkxvuxdBfpT_PI7Yz-FOKnu1R6HsJeDCjn12Sk3vmAktV2zb');
CkStringBuilder_Append(sbJwk,'34MCdy7cpdTh_YVr7tss2u6vneTwrA86rZtu5Mbr1C1XsmvkxHQAdYo0",');
CkStringBuilder_Append(sbJwk,'"dq":"h_96-mK1R_7glhsum81dZxjTnYynPbZpHziZjeeHcXYsXaaMwkOlODsWa');
CkStringBuilder_Append(sbJwk,'7I9xXDoRwbKgB719rrmI2oKr6N3Do9U0ajaHF-NKJnwgjMd2w9cjz3_-ky');
CkStringBuilder_Append(sbJwk,'NlxAr2v4IKhGNpmM5iIgOS1VZnOZ68m6_pbLBSp3nssTdlqvd0tIiTHU",');
CkStringBuilder_Append(sbJwk,'"qi":"IYd7DHOhrWvxkwPQsRM2tOgrjbcrfvtQJipd-DlcxyVuuM9sQLdgjVk2o');
CkStringBuilder_Append(sbJwk,'y26F0EmpScGLq2MowX7fhd_QJQ3ydy5cY7YIBi87w93IKLEdfnbJtoOPLU');
CkStringBuilder_Append(sbJwk,'W0ITrJReOgo1cq9SbsxYawBgfp_gh6A5603k2-ZQwVK0JKSHuLFkuQ3U"');
CkStringBuilder_Append(sbJwk,'}');

rsaKey := CkPrivateKey_Create();
// Note: This example loads the RSA key from JWK format.  Any format can be loaded
// into the private key object. (See the online reference documentation..)
success := CkPrivateKey_LoadJwk(rsaKey,CkStringBuilder__getAsString(sbJwk));
if (success <> True) then
  begin
    Memo1.Lines.Add(CkPrivateKey__lastErrorText(rsaKey));
    Exit;
  end;

// Create the JWS Protected Header
jwsProtHdr := CkJsonObject_Create();
CkJsonObject_AppendString(jwsProtHdr,'alg','PS256');

jws := CkJws_Create();

// Set the protected header:
signatureIndex := 0;
CkJws_SetProtectedHeader(jws,signatureIndex,jwsProtHdr);

// Set the RSA key:
CkJws_SetPrivateKey(jws,signatureIndex,rsaKey);

// Set the payload.
bIncludeBom := False;
payloadStr := 'In our village, folks say God crumbles up the old moon into stars.';
CkJws_SetPayload(jws,payloadStr,'utf-8',bIncludeBom);

// Create the JWS
// By default, the compact serialization is used.
jwsCompact := CkJws__createJws(jws);
if (CkJws_getLastMethodSuccess(jws) <> True) then
  begin
    Memo1.Lines.Add(CkJws__lastErrorText(jws));
    Exit;
  end;

Memo1.Lines.Add('JWS: ' + jwsCompact);

// Note: RSA PSS padding uses random values, so the output will be different each time a signature is produced.
// sample output:
// JWS: eyJhbGciOiJQUzI1NiJ9.SW4gb3VyIHZpbGxhZ2UsIGZvbGtzIHNheSBHb2QgY3J1bWJsZXMgdXAgdGhlIG9sZCBtb29uIGludG8gc3RhcnMu.TRWhwRo5dMv9-8OzrInfJTwmUGYgjLfHk8lqF072ND-FmLWEBnUTOpY8oJXp8FdWw2SalbdOeNlrtlJjwk4XK8Ql2iJ_2qMCtxsvLPhKBOqFoAF4aBvTOEDVJDxf0DaBSiydEEtfTVV2iwBcjWabu5J2XieR5y7QZQtuHsn7T3qKBvCcCejN3Y2oqAT3qMHvu1fTms1r_91wBn_K7Wjd9UkZ1n02qQcUHJznR_OF2BgN7_KWIDAF9ZS9keoju2NPpPelO4yxa2XUPnehY3G7dHKoCxUEQR4d2Xc5voqDASTVCDqQS4PVOZdvT3Ein6-SanAlCwbWBbkvT8g6-5PImQ

// Now load the JWS, validate, and recover the original text.
jws2 := CkJws_Create();

// Load the JWS.
success := CkJws_LoadJws(jws2,jwsCompact);

rsaPubKey := CkPrivateKey_GetPublicKey(rsaKey);

// Set the RSA public key used for validation.
signatureIndex := 0;
CkJws_SetPublicKey(jws2,signatureIndex,rsaPubKey);
CkPublicKey_Dispose(rsaPubKey);

// Validate the 1st (and only) signature at index 0..
v := CkJws_Validate(jws2,signatureIndex);
if (v < 0) then
  begin
    // Perhaps Chilkat was not unlocked or the trial expired..
    Memo1.Lines.Add('Method call failed for some other reason.');
    Memo1.Lines.Add(CkJws__lastErrorText(jws2));
    Exit;
  end;
if (v = 0) then
  begin
    Memo1.Lines.Add('Invalid signature.  The RSA key was incorrect, the JWS was invalid, or both.');
    Exit;
  end;

// If we get here, the signature was validated..
Memo1.Lines.Add('Signature validated.');

// Recover the original content:
Memo1.Lines.Add(CkJws__getPayload(jws2,'utf-8'));

// Examine the protected header:
joseHeader := CkJws_GetProtectedHeader(jws2,signatureIndex);
if (CkJws_getLastMethodSuccess(jws2) <> True) then
  begin
    Memo1.Lines.Add('No protected header found at the given index.');
    Exit;
  end;
CkJsonObject_putEmitCompact(joseHeader,False);

Memo1.Lines.Add('Protected (JOSE) header:');
Memo1.Lines.Add(CkJsonObject__emit(joseHeader));
CkJsonObject_Dispose(joseHeader);

// Output:

// 	Signature validated.
// 	In our village, folks say God crumbles up the old moon into stars.
// 	Protected (JOSE) header:
// 	{ 
// 	  "alg": "PS256"
// 	}

CkStringBuilder_Dispose(sbJwk);
CkPrivateKey_Dispose(rsaKey);
CkJsonObject_Dispose(jwsProtHdr);
CkJws_Dispose(jws);
CkJws_Dispose(jws2);

end;