Delphi DLL Requires Chilkat v11.0.0+

RSA Encrypt RSA/ECB/OAEPWithSHA1AndMGF1Padding

See more RSA Examples

Demonstrates how to RSA encrypt using RSA/ECB/OAEPWithSHA1AndMGF1Padding. Also demonstrates RSA/ECB/OAEPWithSHA-256AndMGF1Padding. Both of these terms are from Java's JCE. Note: In this context, "ECB" doesn't actually mean anything. It's a symmetric cipher mode that doesn't apply (or make sense) in this context. Delphi DLL

var
success: Boolean;
rsa: HCkRsa;
pubkey: HCkPublicKey;
plainText: PWideChar;
usePrivateKey: Boolean;
encryptedStr: PWideChar;
rsa2: HCkRsa;
privKey: HCkPrivateKey;
originalStr: PWideChar;

begin
success := False;

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

rsa := CkRsa_Create();

//  First load a public key object with a public key.
//  In this case, we'll load it from a file.
pubkey := CkPublicKey_Create();
success := CkPublicKey_LoadFromFile(pubkey,'qa_data/pem/rsa_public.pem');
if (success = False) then
  begin
    Memo1.Lines.Add(CkPublicKey__lastErrorText(pubkey));
    Exit;
  end;

//  RSA encryption is limited to small amounts of data. The limit
//  is typically a few hundred bytes and is based on the key size and
//  padding (OAEP vs. PKCS1_5).  RSA encryption is typically used for
//  encrypting hashes or symmetric (bulk encryption algorithm) secret keys.
plainText := 'Time is an illusion. Lunchtime doubly so.';

//  Import the public key to be used for encrypting.
success := CkRsa_UsePublicKey(rsa,pubkey);

//  To get OAEP padding, set the PkcsPadding property equal to 0
CkRsa_putPkcsPadding(rsa,False);
CkRsa_putOaepHash(rsa,'sha256');

//  Indicate we'll want hex output
CkRsa_putEncodingMode(rsa,'hex');

//  Encrypt..
usePrivateKey := False;
encryptedStr := CkRsa__encryptStringENC(rsa,plainText,usePrivateKey);
Memo1.Lines.Add(encryptedStr);

//  -------------------------------------------------
//  Now decrypt with the matching private key.
rsa2 := CkRsa_Create();

privKey := CkPrivateKey_Create();
success := CkPrivateKey_LoadEncryptedPem(privKey,'qa_data/pem/rsa_passwd.pem','passwd');
if (success = False) then
  begin
    Memo1.Lines.Add(CkPrivateKey__lastErrorText(privKey));
    Exit;
  end;

success := CkRsa_UsePrivateKey(rsa2,privKey);

//  Make sure we have the same settings used for encryption.
CkRsa_putPkcsPadding(rsa2,False);
CkRsa_putEncodingMode(rsa2,'hex');
CkRsa_putOaepHash(rsa2,'sha256');

originalStr := CkRsa__decryptStringENC(rsa2,encryptedStr,True);

Memo1.Lines.Add(originalStr);

CkRsa_Dispose(rsa);
CkPublicKey_Dispose(pubkey);
CkRsa_Dispose(rsa2);
CkPrivateKey_Dispose(privKey);