Delphi DLL Requires Chilkat v11.0.0+

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 DLL

var
success: Boolean;
pubkey: HCkPublicKey;
sbPem: HCkStringBuilder;
bCrlf: Boolean;
originalData: PWideChar;
crypt: HCkCrypt2;
hashBase64: PWideChar;
rsa: HCkRsa;
bUsePrivateKey: Boolean;
encryptedStr: PWideChar;

begin
success := False;

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

pubkey := CkPublicKey_Create();

sbPem := CkStringBuilder_Create();
bCrlf := True;
CkStringBuilder_AppendLine(sbPem,'-----BEGIN PUBLIC KEY-----',bCrlf);
CkStringBuilder_AppendLine(sbPem,'MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA33TqqLR3eeUmDtHS89qF',bCrlf);
CkStringBuilder_AppendLine(sbPem,'3p4MP7Wfqt2Zjj3lZjLjjCGDvwr9cJNlNDiuKboODgUiT4ZdPWbOiMAfDcDzlOxA',bCrlf);
CkStringBuilder_AppendLine(sbPem,'04DDnEFGAf+kDQiNSe2ZtqC7bnIc8+KSG/qOGQIVaay4Ucr6ovDkykO5Hxn7OU7s',bCrlf);
CkStringBuilder_AppendLine(sbPem,'Jp9TP9H0JH8zMQA6YzijYH9LsupTerrY3U6zyihVEDXXOv08vBHk50BMFJbE9iwF',bCrlf);
CkStringBuilder_AppendLine(sbPem,'wnxCsU5+UZUZYw87Uu0n4LPFS9BT8tUIvAfnRXIEWCha3KbFWmdZQZlyrFw0buUE',bCrlf);
CkStringBuilder_AppendLine(sbPem,'f0YN3/Q0auBkdbDR/ES2PbgKTJdkjc/rEeM0TxvOUf7HuUNOhrtAVEN1D5uuxE1W',bCrlf);
CkStringBuilder_AppendLine(sbPem,'SwIDAQAB',bCrlf);
CkStringBuilder_AppendLine(sbPem,'-----END PUBLIC KEY-----',bCrlf);

//  Load the public key object from the PEM. 
success := CkPublicKey_LoadFromString(pubkey,CkStringBuilder__getAsString(sbPem));
if (success = False) then
  begin
    Memo1.Lines.Add(CkPublicKey__lastErrorText(pubkey));
    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 := CkCrypt2_Create();
CkCrypt2_putHashAlgorithm(crypt,'SHA-256');
CkCrypt2_putEncodingMode(crypt,'base64');
hashBase64 := CkCrypt2__hashStringENC(crypt,originalData);

//  Setup RSA to use OAEP padding with SHA-1 for the mask function.
rsa := CkRsa_Create();
CkRsa_putPkcsPadding(rsa,False);
CkRsa_putOaepHash(rsa,'SHA256');
CkRsa_UsePublicKey(rsa,pubkey);
CkRsa_putEncodingMode(rsa,'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).
CkRsa_putCharset(rsa,'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 := False;
encryptedStr := CkRsa__encryptStringENC(rsa,hashBase64,bUsePrivateKey);
if (CkRsa_getLastMethodSuccess(rsa) = False) then
  begin
    Memo1.Lines.Add(CkRsa__lastErrorText(rsa));
    Exit;
  end;

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

CkPublicKey_Dispose(pubkey);
CkStringBuilder_Dispose(sbPem);
CkCrypt2_Dispose(crypt);
CkRsa_Dispose(rsa);