Delphi DLL Requires Chilkat v11.0.0+

RSA SHA256 Signature using Private Key from Java Keystore

See more RSA Examples

Signs plaintext using RSA SHA256 using a key from a Java keystore.

Duplicatest this code:

KeyStore keystore; // key repository for keys containing signature certificate
String alias; // alias for the certificate in the key repository
String password; // password for the certificate's private key
String plaintext; // text being signed


Signature signature = Signature.getInstance("SHA256withRSA");
signature.initSign((PrivateKey) keystore.getKey(alias, password.toCharArray()));
signature.update(plaintext.getBytes("UTF-8"));
byte[] rsa_text= signature.sign();

Delphi DLL

var
success: Boolean;
jks: HCkJavaKeyStore;
jksPassword: PWideChar;
privKeyPassword: PWideChar;
caseSensitive: Boolean;
privKey: HCkPrivateKey;
rsa: HCkRsa;
binarySignature: HCkByteData;
plaintext: PWideChar;
signatureStr: PWideChar;

begin
success := False;

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

jks := CkJavaKeyStore_Create();

jksPassword := 'secret';

//  Load the Java keystore from a file.  The JKS file password is used
//  to verify the keyed digest that is found at the very end of the keystore.
//  It verifies that the keystore has not been modified.
success := CkJavaKeyStore_LoadFile(jks,jksPassword,'qa_data/jks/sample_secret.jks');
if (success = False) then
  begin
    Memo1.Lines.Add(CkJavaKeyStore__lastErrorText(jks));
    Exit;
  end;

//  Get the private key from the JKS.
//  The private key password may be different than the file password.
privKeyPassword := 'secret';
caseSensitive := False;
privKey := CkPrivateKey_Create();
success := CkJavaKeyStore_PrivateKeyOf(jks,privKeyPassword,'some.alias',caseSensitive,privKey);
if (success = False) then
  begin
    Memo1.Lines.Add(CkJavaKeyStore__lastErrorText(jks));
    Exit;
  end;

//  Establish the RSA object and tell it to use the private key..
rsa := CkRsa_Create();

success := CkRsa_UsePrivateKey(rsa,privKey);
if (success = False) then
  begin
    Memo1.Lines.Add(CkRsa__lastErrorText(rsa));
    Exit;
  end;

//  Indicate we'll be signing the utf-8 byte representation of the string..
CkRsa_putCharset(rsa,'utf-8');

//  Sign some plaintext using RSA-SHA256
binarySignature := CkByteData_Create();
plaintext := 'this is the text to be signed';
success := CkRsa_SignString(rsa,plaintext,'SHA256',binarySignature);
if (CkRsa_getLastMethodSuccess(rsa) = False) then
  begin
    Memo1.Lines.Add(CkRsa__lastErrorText(rsa));
    Exit;
  end;

//  Alternatively, if the signature is desired in some encoded string form,
//  such as base64, base64-url, hex, etc.
CkRsa_putEncodingMode(rsa,'base64-url');
signatureStr := CkRsa__signStringENC(rsa,plaintext,'SHA256');
Memo1.Lines.Add('base64-url RSA signature: ' + signatureStr);

CkJavaKeyStore_Dispose(jks);
CkPrivateKey_Dispose(privKey);
CkRsa_Dispose(rsa);
CkByteData_Dispose(binarySignature);