Алгоритм шифрования AES

Автор: Пользователь скрыл имя, 26 Ноября 2011 в 09:27, курсовая работа

Краткое описание

Шифрование — способ преобразования открытой информации в закрытую и обратно. Применяется для хранения важной информации в ненадёжных источниках или передачи её по незащищённым каналам связи. Согласно ГОСТ 28147-89, шифрование подразделяется на процесс зашифровывания и расшифровывания.
В зависимости от алгоритма преобразования данных, методы шифрования подразделяются на гарантированной или временной крипто-стойкости.

Оглавление

Введение 2
История AES 3
Описание AES 4
Программная реализация алгоритма AES 11
Листинг программы 13
Заключение 32
Список использованной литературы 33

Скачать в ZIP (342.70 Кб) Сколько стоит заказать работу?
Файлы: 1 файл

Курсач.docx

— 365.25 Кб (Скачать)

  W2 := ForwardTable[Byte(T1[3] shr 16)]; W3 := ForwardTable[Byte(T1[0] shr 24)];

  T0[1] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[9];

  W0 := ForwardTable[Byte(T1[2])]; W1 := ForwardTable[Byte(T1[3] shr 8)];

  W2 := ForwardTable[Byte(T1[0] shr 16)]; W3 := ForwardTable[Byte(T1[1] shr 24)];

  T0[2] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[10];

  W0 := ForwardTable[Byte(T1[3])]; W1 := ForwardTable[Byte(T1[0] shr 8)];

  W2 := ForwardTable[Byte(T1[1] shr 16)]; W3 := ForwardTable[Byte(T1[2] shr 24)];

  T0[3] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[11];

  // раунд 3

  W0 := ForwardTable[Byte(T0[0])]; W1 := ForwardTable[Byte(T0[1] shr 8)];

  W2 := ForwardTable[Byte(T0[2] shr 16)]; W3 := ForwardTable[Byte(T0[3] shr 24)];

  T1[0] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[12];

  W0 := ForwardTable[Byte(T0[1])]; W1 := ForwardTable[Byte(T0[2] shr 8)];

  W2 := ForwardTable[Byte(T0[3] shr 16)]; W3 := ForwardTable[Byte(T0[0] shr 24)];

  T1[1] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[13];

  W0 := ForwardTable[Byte(T0[2])]; W1 := ForwardTable[Byte(T0[3] shr 8)];

  W2 := ForwardTable[Byte(T0[0] shr 16)]; W3 := ForwardTable[Byte(T0[1] shr 24)];

  T1[2] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[14];

  W0 := ForwardTable[Byte(T0[3])]; W1 := ForwardTable[Byte(T0[0] shr 8)];

  W2 := ForwardTable[Byte(T0[1] shr 16)]; W3 := ForwardTable[Byte(T0[2] shr 24)];

  T1[3] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[15];

  // раунд 4

  W0 := ForwardTable[Byte(T1[0])]; W1 := ForwardTable[Byte(T1[1] shr 8)];

  W2 := ForwardTable[Byte(T1[2] shr 16)]; W3 := ForwardTable[Byte(T1[3] shr 24)];

  T0[0] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[16];

  W0 := ForwardTable[Byte(T1[1])]; W1 := ForwardTable[Byte(T1[2] shr 8)];

  W2 := ForwardTable[Byte(T1[3] shr 16)]; W3 := ForwardTable[Byte(T1[0] shr 24)];

  T0[1] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[17];

  W0 := ForwardTable[Byte(T1[2])]; W1 := ForwardTable[Byte(T1[3] shr 8)];

  W2 := ForwardTable[Byte(T1[0] shr 16)]; W3 := ForwardTable[Byte(T1[1] shr 24)];

  T0[2] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[18];

  W0 := ForwardTable[Byte(T1[3])]; W1 := ForwardTable[Byte(T1[0] shr 8)];

  W2 := ForwardTable[Byte(T1[1] shr 16)]; W3 := ForwardTable[Byte(T1[2] shr 24)];

  T0[3] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[19];

  // раунд 5

  W0 := ForwardTable[Byte(T0[0])]; W1 := ForwardTable[Byte(T0[1] shr 8)];

  W2 := ForwardTable[Byte(T0[2] shr 16)]; W3 := ForwardTable[Byte(T0[3] shr 24)];

  T1[0] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[20];

  W0 := ForwardTable[Byte(T0[1])]; W1 := ForwardTable[Byte(T0[2] shr 8)];

  W2 := ForwardTable[Byte(T0[3] shr 16)]; W3 := ForwardTable[Byte(T0[0] shr 24)];

  T1[1] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[21];

  W0 := ForwardTable[Byte(T0[2])]; W1 := ForwardTable[Byte(T0[3] shr 8)];

  W2 := ForwardTable[Byte(T0[0] shr 16)]; W3 := ForwardTable[Byte(T0[1] shr 24)];

  T1[2] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[22];

  W0 := ForwardTable[Byte(T0[3])]; W1 := ForwardTable[Byte(T0[0] shr 8)];

  W2 := ForwardTable[Byte(T0[1] shr 16)]; W3 := ForwardTable[Byte(T0[2] shr 24)];

  T1[3] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[23];

  // раунд 6

  W0 := ForwardTable[Byte(T1[0])]; W1 := ForwardTable[Byte(T1[1] shr 8)];

  W2 := ForwardTable[Byte(T1[2] shr 16)]; W3 := ForwardTable[Byte(T1[3] shr 24)];

  T0[0] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[24];

  W0 := ForwardTable[Byte(T1[1])]; W1 := ForwardTable[Byte(T1[2] shr 8)];

  W2 := ForwardTable[Byte(T1[3] shr 16)]; W3 := ForwardTable[Byte(T1[0] shr 24)];

  T0[1] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[25];

  W0 := ForwardTable[Byte(T1[2])]; W1 := ForwardTable[Byte(T1[3] shr 8)];

  W2 := ForwardTable[Byte(T1[0] shr 16)]; W3 := ForwardTable[Byte(T1[1] shr 24)];

  T0[2] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[26];

  W0 := ForwardTable[Byte(T1[3])]; W1 := ForwardTable[Byte(T1[0] shr 8)];

  W2 := ForwardTable[Byte(T1[1] shr 16)]; W3 := ForwardTable[Byte(T1[2] shr 24)];

  T0[3] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[27];

  // раунд 7

  W0 := ForwardTable[Byte(T0[0])]; W1 := ForwardTable[Byte(T0[1] shr 8)];

  W2 := ForwardTable[Byte(T0[2] shr 16)]; W3 := ForwardTable[Byte(T0[3] shr 24)];

  T1[0] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[28];

  W0 := ForwardTable[Byte(T0[1])]; W1 := ForwardTable[Byte(T0[2] shr 8)];

  W2 := ForwardTable[Byte(T0[3] shr 16)]; W3 := ForwardTable[Byte(T0[0] shr 24)];

  T1[1] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[29];

  W0 := ForwardTable[Byte(T0[2])]; W1 := ForwardTable[Byte(T0[3] shr 8)];

  W2 := ForwardTable[Byte(T0[0] shr 16)]; W3 := ForwardTable[Byte(T0[1] shr 24)];

  T1[2] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[30];

  W0 := ForwardTable[Byte(T0[3])]; W1 := ForwardTable[Byte(T0[0] shr 8)];

  W2 := ForwardTable[Byte(T0[1] shr 16)]; W3 := ForwardTable[Byte(T0[2] shr 24)];

  T1[3] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[31];

  // раунд 8

  W0 := ForwardTable[Byte(T1[0])]; W1 := ForwardTable[Byte(T1[1] shr 8)];

  W2 := ForwardTable[Byte(T1[2] shr 16)]; W3 := ForwardTable[Byte(T1[3] shr 24)];

  T0[0] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[32];

  W0 := ForwardTable[Byte(T1[1])]; W1 := ForwardTable[Byte(T1[2] shr 8)];

  W2 := ForwardTable[Byte(T1[3] shr 16)]; W3 := ForwardTable[Byte(T1[0] shr 24)];

  T0[1] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[33];

  W0 := ForwardTable[Byte(T1[2])]; W1 := ForwardTable[Byte(T1[3] shr 8)];

  W2 := ForwardTable[Byte(T1[0] shr 16)]; W3 := ForwardTable[Byte(T1[1] shr 24)];

  T0[2] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[34];

  W0 := ForwardTable[Byte(T1[3])]; W1 := ForwardTable[Byte(T1[0] shr 8)];

  W2 := ForwardTable[Byte(T1[1] shr 16)]; W3 := ForwardTable[Byte(T1[2] shr 24)];

  T0[3] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[35];

  // раунд 9

  W0 := ForwardTable[Byte(T0[0])]; W1 := ForwardTable[Byte(T0[1] shr 8)];

  W2 := ForwardTable[Byte(T0[2] shr 16)]; W3 := ForwardTable[Byte(T0[3] shr 24)];

  T1[0] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[36];

  W0 := ForwardTable[Byte(T0[1])]; W1 := ForwardTable[Byte(T0[2] shr 8)];

  W2 := ForwardTable[Byte(T0[3] shr 16)]; W3 := ForwardTable[Byte(T0[0] shr 24)];

  T1[1] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[37];

  W0 := ForwardTable[Byte(T0[2])]; W1 := ForwardTable[Byte(T0[3] shr 8)];

  W2 := ForwardTable[Byte(T0[0] shr 16)]; W3 := ForwardTable[Byte(T0[1] shr 24)];

  T1[2] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[38];

  W0 := ForwardTable[Byte(T0[3])]; W1 := ForwardTable[Byte(T0[0] shr 8)];

  W2 := ForwardTable[Byte(T0[1] shr 16)]; W3 := ForwardTable[Byte(T0[2] shr 24)];

  T1[3] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[39];

  // Последний раунд преобраобразований

  W0 := LastForwardTable[Byte(T1[0])]; W1 := LastForwardTable[Byte(T1[1] shr 8)];

  W2 := LastForwardTable[Byte(T1[2] shr 16)]; W3 := LastForwardTable[Byte(T1[3] shr 24)];

  T0[0] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[40];

  W0 := LastForwardTable[Byte(T1[1])]; W1 := LastForwardTable[Byte(T1[2] shr 8)];

  W2 := LastForwardTable[Byte(T1[3] shr 16)]; W3 := LastForwardTable[Byte(T1[0] shr 24)];

  T0[1] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[41];

  W0 := LastForwardTable[Byte(T1[2])]; W1 := LastForwardTable[Byte(T1[3] shr 8)];

  W2 := LastForwardTable[Byte(T1[0] shr 16)]; W3 := LastForwardTable[Byte(T1[1] shr 24)];

  T0[2] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[42];

  W0 := LastForwardTable[Byte(T1[3])]; W1 := LastForwardTable[Byte(T1[0] shr 8)];

  W2 := LastForwardTable[Byte(T1[1] shr 16)]; W3 := LastForwardTable[Byte(T1[2] shr 24)];

  T0[3] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[43];

  // Завершение

  PLongWord(@OutBuf[0])^ := T0[0]; PLongWord(@OutBuf[4])^ := T0[1];

  PLongWord(@OutBuf[8])^ := T0[2]; PLongWord(@OutBuf[12])^ := T0[3];

end;

procedure ExpandAESKeyForDecryption(var ExpandedKey: TAESExpandedKey128);

var

  I: integer;

  U, F2, F4, F8, F9: longword;

begin

  for I := 1 to 9 do

  begin

    //Процедура расширения ключа

    F9 := ExpandedKey[I * 4];

    U := F9 and $80808080;

    F2 := ((F9 and $7F7F7F7F) shl 1) xor ((U - (U shr 7)) and $1B1B1B1B);

    U := F2 and $80808080;

    F4 := ((F2 and $7F7F7F7F) shl 1) xor ((U - (U shr 7)) and $1B1B1B1B);

    U := F4 and $80808080;

    F8 := ((F4 and $7F7F7F7F) shl 1) xor ((U - (U shr 7)) and $1B1B1B1B);

    F9 := F9 xor F8;

    ExpandedKey[I * 4] := F2 xor F4 xor F8 xor

      (((F2 xor F9) shl 24) or ((F2 xor F9) shr 8)) xor

      (((F4 xor F9) shl 16) or ((F4 xor F9) shr 16)) xor ((F9 shl 8) or (F9 shr 24));

    F9 := ExpandedKey[I * 4 + 1];

    U := F9 and $80808080;

    F2 := ((F9 and $7F7F7F7F) shl 1) xor ((U - (U shr 7)) and $1B1B1B1B);

    U := F2 and $80808080;

    F4 := ((F2 and $7F7F7F7F) shl 1) xor ((U - (U shr 7)) and $1B1B1B1B);

    U := F4 and $80808080;

    F8 := ((F4 and $7F7F7F7F) shl 1) xor ((U - (U shr 7)) and $1B1B1B1B);

    F9 := F9 xor F8;

    ExpandedKey[I * 4 + 1] := F2 xor F4 xor F8 xor

      (((F2 xor F9) shl 24) or ((F2 xor F9) shr 8)) xor

      (((F4 xor F9) shl 16) or ((F4 xor F9) shr 16)) xor ((F9 shl 8) or (F9 shr 24));

    F9 := ExpandedKey[I * 4 + 2];

    U := F9 and $80808080;

    F2 := ((F9 and $7F7F7F7F) shl 1) xor ((U - (U shr 7)) and $1B1B1B1B);

    U := F2 and $80808080;

    F4 := ((F2 and $7F7F7F7F) shl 1) xor ((U - (U shr 7)) and $1B1B1B1B);

    U := F4 and $80808080;

    F8 := ((F4 and $7F7F7F7F) shl 1) xor ((U - (U shr 7)) and $1B1B1B1B);

    F9 := F9 xor F8;

    ExpandedKey[I * 4 + 2] := F2 xor F4 xor F8 xor

      (((F2 xor F9) shl 24) or ((F2 xor F9) shr 8)) xor

      (((F4 xor F9) shl 16) or ((F4 xor F9) shr 16)) xor ((F9 shl 8) or (F9 shr 24));

    F9 := ExpandedKey[I * 4 + 3];

    U := F9 and $80808080;

    F2 := ((F9 and $7F7F7F7F) shl 1) xor ((U - (U shr 7)) and $1B1B1B1B);

    U := F2 and $80808080;

    F4 := ((F2 and $7F7F7F7F) shl 1) xor ((U - (U shr 7)) and $1B1B1B1B);

    U := F4 and $80808080;

    F8 := ((F4 and $7F7F7F7F) shl 1) xor ((U - (U shr 7)) and $1B1B1B1B);

    F9 := F9 xor F8;

    ExpandedKey[I * 4 + 3] := F2 xor F4 xor F8 xor

      (((F2 xor F9) shl 24) or ((F2 xor F9) shr 8)) xor

      (((F4 xor F9) shl 16) or ((F4 xor F9) shr 16)) xor ((F9 shl 8) or (F9 shr 24));

  end;

end;

procedure ExpandAESKeyForDecryption(const Key: TAESKey128; var ExpandedKey: TAESExpandedKey128);

begin

  ExpandAESKeyForEncryption(Key, ExpandedKey);

  //Подготовка  ключа (расширение)

  ExpandAESKeyForDecryption(ExpandedKey);

  //Расширение  ключа для дешифрования

end;

procedure DecryptAES(const InBuf: TAESBuffer; const Key: TAESExpandedKey128;

  var OutBuf: TAESBuffer);

var

  T0, T1: array [0..3] of longword;

  W0, W1, W2, W3: longword;

begin

  // Инициализация

  T0[0] := PLongWord(@InBuf[0])^ xor Key[40];

  T0[1] := PLongWord(@InBuf[4])^ xor Key[41];

  T0[2] := PLongWord(@InBuf[8])^ xor Key[42];

  T0[3] := PLongWord(@InBuf[12])^ xor Key[43];

  // Преобразования выполняются 10 раз

  // раунд 1

  W0 := InverseTable[Byte(T0[0])]; W1 := InverseTable[Byte(T0[3] shr 8)];

  W2 := InverseTable[Byte(T0[2] shr 16)]; W3 := InverseTable[Byte(T0[1] shr 24)];

  T1[0] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

    xor ((W3 shl 24) or (W3 shr 8))) xor Key[36];

  W0 := InverseTable[Byte(T0[1])]; W1 := InverseTable[Byte(T0[0] shr 8)];

  W2 := InverseTable[Byte(T0[3] shr 16)]; W3 := InverseTable[Byte(T0[2] shr 24)];

  T1[1] := (W0 xor ((W1 shl 8) or (W1 shr 24)) xor ((W2 shl 16) or (W2 shr 16))

Информация о работе Алгоритм шифрования AES