TCipher.GetRC5

Creates new TCipher instance implementing customized RC5 algorithm

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Syntax

class function TCipher.GetRC5(AAlgID: TAlgID; BlockSize, Rounds: Cardinal): TCipher; static;

Remarks

• TCipher.GetRC5 method is supported by built-in engine only
• RC5 is a block cipher
• RC5 block size is 4, 8 or 16 bytes (32, 64 or 128 bits)
• RC5 key length is 0..255 RC5 words
• RC5 word is:
  • 2 bytes for 4-byte block size
  • 4 bytes for 8-byte block size
  • 8 bytes for 16-byte block size
• RC5 number of rounds is 1..255
• Standard RC5 implementation created by TCipher.GetInstance method has 8-byte block size and 12 rounds.

Examples

Encrypt file with RC5 algorithm having 128-bit block size and 20 rounds in CBC mode of operation:

uses
  tfArrays, tfCiphers;

procedure EncryptCBC(const FileName: string; const Key, IV: ByteArray);
var
  Cipher: TCipher;

begin
  Cipher:= TCipher.GetRC5(CBC_ENCRYPT, 16, 20);
  try
    Cipher.Init(Key, IV)
          .EncryptFile(FileName, FileName + '.rc5');
  finally
    Cipher.Burn;
  end;
end;