(Delphi ActiveX) Duplicate SQL Server ENCRYPTBYPASSPHRASE

See more Encryption Examples

Demonstrates how to duplicate SQL Server's ENCRYPTBYPASSPHRASE.

Chilkat for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

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
password: WideString;
encryptedHex_v1: WideString;
encryptedHex_v2: WideString;
sbEncHex: TChilkatStringBuilder;
crypt: TChilkatCrypt2;
v1: Integer;
ivLen: Integer;
hashAlg: WideString;
ivHex: WideString;
sbPassword: TChilkatStringBuilder;
pwd_hash: WideString;
sbKey: TChilkatStringBuilder;
bd: TChilkatBinData;
plainText: WideString;
encryptor: TChilkatCrypt2;
prng: TChilkatPrng;
plainTextLen: Integer;
bdData: TChilkatBinData;
sbEnc: TChilkatStringBuilder;

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

// For SQL Server 2008 - SQL Server 2016 we must use TripleDES with SHA1
// For SQL Server 2017 and later, use AES256 / SHA256.

password := 'tEst1234';
encryptedHex_v1 := '0x010000001E8E7DCDBD4061B951999E25D18445D2305474D2D71EEE98A241C755246F58AB';

// Here's an encrypted string using AES256/SHA256
encryptedHex_v2 := '0x02000000FFE880C0354780481E64EF25B6197A02E2A854A4BA9D8D9BDDFDAB27EB56537ABDA0B1D9C4D1050C91B313550DECF429';

sbEncHex := TChilkatStringBuilder.Create(Self);
sbEncHex.Append(encryptedHex_v1);

// If present, we don't want the leading "0x"
if (sbEncHex.StartsWith('0x',0) = 1) then
  begin
    sbEncHex.RemoveCharsAt(0,2);
  end;

crypt := TChilkatCrypt2.Create(Self);
crypt.EncodingMode := 'hex';

// The encrypted hex string will begin with either 01000000 or 02000000
// version 1 is produced by SQL Server 2008 to SQL Server 2016, and we must use TripleDES with SHA1
// version 2 is for SQL Server 2017 and later, and uses AES256 / SHA256.
v1 := sbEncHex.StartsWith('01',0);

ivLen := 0;

if (v1 = 1) then
  begin
    crypt.CryptAlgorithm := '3des';
    crypt.CipherMode := 'cbc';
    crypt.KeyLength := 168;
    ivLen := 8;
    hashAlg := 'sha1';
  end
else
  begin
    crypt.CryptAlgorithm := 'aes';
    crypt.CipherMode := 'cbc';
    crypt.KeyLength := 256;
    ivLen := 16;
    hashAlg := 'sha256';
  end;

// Remove the SQL Server version info (i.e. the "01000000")
sbEncHex.RemoveCharsAt(0,8);

// Get the IV part of the sbEncHex, and also remove it from the StringBuilder.
ivHex := sbEncHex.GetRange(0,ivLen * 2,1);
Memo1.Lines.Add('IV = ' + ivHex);
crypt.SetEncodedIV(ivHex,'hex');

sbPassword := TChilkatStringBuilder.Create(Self);
sbPassword.Append(password);
pwd_hash := sbPassword.GetHash(hashAlg,'hex','utf-16');
sbKey := TChilkatStringBuilder.Create(Self);
sbKey.Append(pwd_hash);
if (v1 = 1) then
  begin
    // For v1, we only want the 1st 16 bytes of the 20 byte hash.
    // (remember, the hex encoding uses 2 chars per byte, so we remove the last 8 chars)
    sbKey.Shorten(8);
  end;

Memo1.Lines.Add('crypt key: ' + sbKey.GetAsString());

crypt.SetEncodedKey(sbKey.GetAsString(),'hex');

// Decrypt
bd := TChilkatBinData.Create(Self);
bd.AppendEncoded(sbEncHex.GetAsString(),'hex');
crypt.DecryptBd(bd.ControlInterface);

// The result is composed of a header of 8 bytes which we can discard.
// The remainder is the decrypted text.

// The header we are discarding is composed of:
// Bytes 0-3: Magic number equal to 0DF0ADBA
// Bytes 4-5: Number of integrity bytes, which is 0 unless an authenticator is used. We're assuming no authenticator is used.
// Bytes 6-7: Number of plain-text bytes. We really don't need this because the CBC padding takes care of it.

// Therefore, just return the data after the 1st 8 bytes.
// Assuming the encrypted string was utf-8 text...
bd.RemoveChunk(0,8);
plainText := bd.GetString('utf-8');
Memo1.Lines.Add('decrypted plain text: ' + plainText);

// The output:

// IV = 1E8E7DCDBD4061B9
// crypt key: 710B9C2E61ACCC9570D4112203BD9738
// decrypted plain text: Hello world.

// ------------------------------------------------------------------------------------------
// To encrypt, do the reverse...

// Let's do v1 with TripleDES with SHA1

encryptor := TChilkatCrypt2.Create(Self);
encryptor.EncodingMode := 'hex';

encryptor.CryptAlgorithm := '3des';
encryptor.CipherMode := 'cbc';
encryptor.KeyLength := 168;

// Generate a random 8-byte IV
prng := TChilkatPrng.Create(Self);
ivHex := prng.GenRandom(8,'hex');
encryptor.SetEncodedIV(ivHex,'hex');

// The binary password is generated the same as above.
// We'll use the same password (and same binary password)
encryptor.SetEncodedKey(sbKey.GetAsString(),'hex');

plainTextLen := 8;
plainText := 'ABCD1234';

// Encrypt the header + the plain-text.
bdData := TChilkatBinData.Create(Self);
bdData.AppendEncoded('0DF0ADBA','hex');
bdData.AppendEncoded('0000','hex');
bdData.AppendInt2(plainTextLen,1);
Memo1.Lines.Add('header: ' + bdData.GetEncoded('hex'));
bdData.AppendString(plainText,'utf-8');
encryptor.EncryptBd(bdData.ControlInterface);

// Compose the result..
sbEnc := TChilkatStringBuilder.Create(Self);
sbEnc.Append('0x01000000');
sbEnc.Append(ivHex);
sbEnc.Append(bdData.GetEncoded('hex'));

Memo1.Lines.Add('result: ' + sbEnc.GetAsString());
end;