Delphi DLL Requires Chilkat v11.0.0+

Duplicate openssl dgst -md5 -sign myKey.pem something.txt | openssl enc -base64 -A

See more RSA Examples

Demonstrates how to duplicate the creation of an RSA signature produced by this OpenSSL command:

openssl dgst -md5 -sign myKey.pem something.txt | openssl enc -base64 -A

Delphi DLL

var
success: Boolean;
pkey: HCkPrivateKey;
rsa: HCkRsa;
strData: PWideChar;
base64Sig: PWideChar;

begin
success := False;

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

pkey := CkPrivateKey_Create();

//  Load the private key from an RSA PEM file:
success := CkPrivateKey_LoadPemFile(pkey,'myKey.pem');

rsa := CkRsa_Create();

//  Import the private key into the RSA component:
success := CkRsa_UsePrivateKey(rsa,pkey);
if (success = False) then
  begin
    Memo1.Lines.Add(CkRsa__lastErrorText(rsa));
    Exit;
  end;

//  OpenSSL uses BigEndian byte ordering:
CkRsa_putLittleEndian(rsa,False);

//  The resulting signature will be a Base64 string:
CkRsa_putEncodingMode(rsa,'base64');

//  For simplicity, we're not loading
//  the data to be signed from a file.  We are instead simply
//  using a literal string value.  
strData := 'This is the text to be signed.';

//  Hash the input using MD5, and then sign the hash:
//  Other valid hash algorithm choices are "md2" and "sha-1".
base64Sig := CkRsa__signStringENC(rsa,strData,'md5');

Memo1.Lines.Add(base64Sig);

Memo1.Lines.Add('Success!');

CkPrivateKey_Dispose(pkey);
CkRsa_Dispose(rsa);