Delphi ActiveX

RSA Encrypt Hash using SHA256 hash function and SHA1 mask function

See more RSA Examples

How can this Javascript be duplicated using Chilkat?

function a(e, t) {
                var r = s.pki.publicKeyFromPem(e)
                  , n = r.encrypt(t, "RSA-OAEP", {
                    md: s.md.sha256.create(),
                    mgf1: {
                        md: s.md.sha1.create()
                    }
                });
                return s.util.encode64(n)
            }

Note: The OAEP padding uses random bytes in the padding, and therefore each time encryption happens, even using the same data and key, the result will be different -- but still valid. One should not expect to get the same output.

Delphi ActiveX

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Integer;
pubkey: TPublicKey;
sbPem: TChilkatStringBuilder;
bCrlf: Integer;
originalData: WideString;
crypt: TChilkatCrypt2;
hashBase64: WideString;
rsa: TChilkatRsa;
bUsePrivateKey: Integer;
encryptedStr: WideString;

begin
success := 0;

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

pubkey := TPublicKey.Create(Self);

sbPem := TChilkatStringBuilder.Create(Self);
bCrlf := 1;
sbPem.AppendLine('-----BEGIN PUBLIC KEY-----',bCrlf);
sbPem.AppendLine('MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA33TqqLR3eeUmDtHS89qF',bCrlf);
sbPem.AppendLine('3p4MP7Wfqt2Zjj3lZjLjjCGDvwr9cJNlNDiuKboODgUiT4ZdPWbOiMAfDcDzlOxA',bCrlf);
sbPem.AppendLine('04DDnEFGAf+kDQiNSe2ZtqC7bnIc8+KSG/qOGQIVaay4Ucr6ovDkykO5Hxn7OU7s',bCrlf);
sbPem.AppendLine('Jp9TP9H0JH8zMQA6YzijYH9LsupTerrY3U6zyihVEDXXOv08vBHk50BMFJbE9iwF',bCrlf);
sbPem.AppendLine('wnxCsU5+UZUZYw87Uu0n4LPFS9BT8tUIvAfnRXIEWCha3KbFWmdZQZlyrFw0buUE',bCrlf);
sbPem.AppendLine('f0YN3/Q0auBkdbDR/ES2PbgKTJdkjc/rEeM0TxvOUf7HuUNOhrtAVEN1D5uuxE1W',bCrlf);
sbPem.AppendLine('SwIDAQAB',bCrlf);
sbPem.AppendLine('-----END PUBLIC KEY-----',bCrlf);

// Load the public key object from the PEM. 
success := pubkey.LoadFromString(sbPem.GetAsString());
if (success = 0) then
  begin
    Memo1.Lines.Add(pubkey.LastErrorText);
    Exit;
  end;

originalData := 'This is the original data to be SHA-256 hashed and RSA encrypted.';

// First we SHA-256 hash the original data to get the hash in base64 format:
crypt := TChilkatCrypt2.Create(Self);
crypt.HashAlgorithm := 'SHA-256';
crypt.EncodingMode := 'base64';
hashBase64 := crypt.HashStringENC(originalData);

// Setup RSA to use OAEP padding with SHA-1 for the mask function.
rsa := TChilkatRsa.Create(Self);
rsa.PkcsPadding := 0;
rsa.OaepHash := 'SHA256';
rsa.UsePublicKey(pubkey.ControlInterface);
rsa.EncodingMode := 'base64';

// We can provide a binary encoding mode, such as "base64", "hex", "base64url", etc.
// for the Charset property.   The Charset property was previously limited to character encodings, such as
// "utf-8", "iso-8859-1", etc.  If a binary encoding is used, then the string passed in is decoded to the binary
// bytes as indicated.  (If an actual charset, such as "utf-8" is used, then the input string is converted to the
// byte representation of the charset, and then encrypted.)

// Given that a hash is composed of non-text binary bytes, we'll set the Charset property equal to "base64" 
// (because we have the base64 hash from above).
rsa.Charset := 'base64';

// Note: The OAEP padding uses random bytes in the padding, and therefore each time encryption happens,
// even using the same data and key, the result will be different --  but still valid.  One should not expect
// to get the same output.
bUsePrivateKey := 0;
encryptedStr := rsa.EncryptStringENC(hashBase64,bUsePrivateKey);
if (rsa.LastMethodSuccess = 0) then
  begin
    Memo1.Lines.Add(rsa.LastErrorText);
    Exit;
  end;

Memo1.Lines.Add('Base64 RSA encrypted output: ' + encryptedStr);
end;