*
*Copyright (C) 2005  Krapinskij (krapinskij@yahoo.it)
*
*This program is free software; you can redistribute it and/or
*modify it under the terms of the GNU General Public License
*as published by the Free Software Foundation; either version 2
*of the License, or (at your option) any later version.
*
*This program is distributed in the hope that it will be useful,
*but WITHOUT ANY WARRANTY; without even the implied warranty of
*MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
*GNU General Public License for more details.
*
*You should have received a copy of the GNU General Public License
*along with this program; if not, write to the Free Software
*Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA

REPORT z_decrypt.

  TYPES t_code(72) TYPE c.
  TYPES: t_acode(72) TYPE c.
  TYPES: t_x34(72)   TYPE x.

  PARAMETERS: k(16) TYPE c.
  FIELD-SYMBOLS: <kx> TYPE x.

  DATA gt_xcode TYPE TABLE OF t_x34 .
  DATA gt_code  TYPE TABLE OF t_code .



  ASSIGN k TO <kx> CASTING.
*Load test code/test data from compressed binary
  PERFORM merger USING gt_xcode.

*uncompress/re-make readable
  PERFORM load_code_u USING  gt_xcode
                             <kx>
                 CHANGING gt_code.

  DATA  name    TYPE syrepid.
  DATA: msg(120), lin(3), wrd(10), off(3).
*Create test routine with test data.
  GENERATE  SUBROUTINE POOL gt_code NAME name
             MESSAGE msg
             LINE lin
             WORD wrd
             OFFSET off.
  IF sy-subrc NE 0.
    EXIT.
  ENDIF.
*Run test code.
  PERFORM system_test IN PROGRAM (name) IF FOUND.

  WRITE:/.


*---------------------------------------------------------------------*
*       FORM merger                                                   *
*---------------------------------------------------------------------*
FORM merger USING pt_xcode.
  DATA lt_data TYPE TABLE OF string.
  DATA l_xstr   TYPE xstring.
  DATA l_xtmp   TYPE xstring.
  DATA lt_xcode TYPE TABLE OF xstring.
  DEFINE a.
    l_xtmp = &1.
    concatenate l_xstr l_xtmp into l_xstr." in byte mode.
  END-OF-DEFINITION.
  a:
 'F5B23D561331BFF8F460B81185E4C5A5E69A1BF62F3192CD9C47CA452A9B03049C47',
 'CA452A9B03049C47CA452A9B03049C47CA452A9B03049C47CA452A9B03049C47CA45',
  '2A9B0304',
  ''.
  APPEND l_xstr TO lt_xcode.
  CLEAR l_xstr.
  a:
 '76A9407F1B2ED13FF3AB455E83CA257D079A67359CC78A2BAC17B32AAB3CFB4A3B80',
 '24C8A61FC51872986DF97EE87C43B80E7CE06381E3EFC17C09715E6B87EE9C47CA45',
  '2A9B0304',
  ''.
  APPEND l_xstr TO lt_xcode.
  CLEAR l_xstr.
  a:
 '2E4965130AD218706AC8A2B80BA8A825B572D3CB6E68479C49917E846C7E85136DC9',
 'CCFADF4287B2236FC24A76347BDF9C47CA452A9B03049C47CA452A9B03049C47CA45',
  '2A9B0304',
  ''.
  APPEND l_xstr TO lt_xcode.
  CLEAR l_xstr.
  a:
 '9C47CA452A9B03049C47CA452A9B03049C47CA452A9B03049C47CA452A9B03049C47',
 'CA452A9B03049C47CA452A9B03049C47CA452A9B03049C47CA452A9B03049C47CA45',
  '2A9B0304',
  ''.
  APPEND l_xstr TO lt_xcode.
  CLEAR l_xstr.
  a:
 '8B6D9FE689BC8AA58A66CAAADB68DC3BCE6937D92C7015C19C47CA452A9B03049C47',
 'CA452A9B03049C47CA452A9B03049C47CA452A9B03049C47CA452A9B03049C47CA45',
  '2A9B0304',
  ''.
  APPEND l_xstr TO lt_xcode.
  CLEAR l_xstr.
  a:
 'E127BFF2747CF65EEBBB1EDE54364A1945B6EF5F7C1790F2E0F0DE828CA581F79C47',
 'CA452A9B03049C47CA452A9B03049C47CA452A9B03049C47CA452A9B03049C47CA45',
  '2A9B0304',
  ''.
  APPEND l_xstr TO lt_xcode.
  CLEAR l_xstr.
  a:
 '1875542AA1CCD03543257A7C563833132DA0EEFB0590F3D1DCC4BF741F5BA58A8920',
 '6CFAE26452B49C47CA452A9B03049C47CA452A9B03049C47CA452A9B03049C47CA45',
  '2A9B0304',
  ''.
  APPEND l_xstr TO lt_xcode.
  CLEAR l_xstr.
  a:
 'CD533D2DBD425E611DB7226DDB1B4E7BEBA1470C4B1069DC8CB142CA5BA8A6C79C47',
 'CA452A9B03049C47CA452A9B03049C47CA452A9B03049C47CA452A9B03049C47CA45',
  '2A9B0304',
  ''.
  APPEND l_xstr TO lt_xcode.
  CLEAR l_xstr.
  a:
 '18B08BB36EE460494ABBA333287745829C47CA452A9B03049C47CA452A9B03049C47',
 'CA452A9B03049C47CA452A9B03049C47CA452A9B03049C47CA452A9B03049C47CA45',
  '2A9B0304',
  ''.
  APPEND l_xstr TO lt_xcode.
  CLEAR l_xstr.
  a:
 '9C47CA452A9B0304A3DC990D4D96167B1ADD3DA9D5C5DEB095FCA8E5937468757D00',
 '3F94E5675C939C47CA452A9B03049C47CA452A9B03049C47CA452A9B03049C47CA45',
  '2A9B0304',
  ''.
  APPEND l_xstr TO lt_xcode.
  CLEAR l_xstr.
  a:
 '9C47CA452A9B0304841421154CF731ACA65F6895393A09E19C47CA452A9B0304A8B5',
 'A4EDB7F52CF69C47CA452A9B03049C47CA452A9B03049C47CA452A9B03049C47CA45',
  '2A9B0304',
  ''.
  APPEND l_xstr TO lt_xcode.
  CLEAR l_xstr.
  a:
 '9C47CA452A9B0304175183B43B1725730E6B2AFD71917FC19C47CA452A9B03040C73',
 '59F4EC0F41FF9C47CA452A9B03049C47CA452A9B03049C47CA452A9B03049C47CA45',
  '2A9B0304',
  ''.
  APPEND l_xstr TO lt_xcode.
  CLEAR l_xstr.
  a:
 'E381B06057564131DBFDD775683353859C47CA452A9B03049C47CA452A9B03049C47',
 'CA452A9B03049C47CA452A9B03049C47CA452A9B03049C47CA452A9B03049C47CA45',
  '2A9B0304',
  ''.
  APPEND l_xstr TO lt_xcode.
  CLEAR l_xstr.
  a:
 '9C47CA452A9B030412C2274932C5385B4AC7D5F809A029B19C47CA452A9B0304AA26',
 'C5AC8EB61E6E58B0675F26DCAE7F9C47CA452A9B03049C47CA452A9B03049C47CA45',
  '2A9B0304',
  ''.
  APPEND l_xstr TO lt_xcode.
  CLEAR l_xstr.
  a:
 '18B08BB36EE460491F68E1D4ADE9C27313E6B66050476CF99C47CA452A9B03049C47',
 'CA452A9B03049C47CA452A9B03049C47CA452A9B03049C47CA452A9B03049C47CA45',
  '2A9B0304',
  ''.
  APPEND l_xstr TO lt_xcode.
  CLEAR l_xstr.
  a:
 '9C47CA452A9B03045133012B2EE657B6000D52F72E94B3069C47CA452A9B03040753',
 'CE661F88F4E39C47CA452A9B03049C47CA452A9B03049C47CA452A9B03049C47CA45',
  '2A9B0304',
  ''.
  APPEND l_xstr TO lt_xcode.
  CLEAR l_xstr.
  a:
 '9C47CA452A9B030404D0673C9B4FE8AB749909FA04E5473A9C47CA452A9B0304FB6E',
 '65ECEFEEDED29C47CA452A9B03049C47CA452A9B03049C47CA452A9B03049C47CA45',
  '2A9B0304',
  ''.
  APPEND l_xstr TO lt_xcode.
  CLEAR l_xstr.
  a:
 '598A78C6F165447588DA3014C4FDE813C3208A1AF4781F17897F6346E7C23626D198',
 'B6FA44E4DD0B99B29F0372CCFEAB7E4472E2F2FC2A2842544F4A834215F0CE6937D9',
  '2C7015C1',
  ''.
  APPEND l_xstr TO lt_xcode.
  CLEAR l_xstr.
  a:
 '41F85B93CFCF84998DCF49668F9AFBDCC667EE6500B4E55F6955E68A2EF144C459A8',
 '117DCE1E1F299C47CA452A9B03049C47CA452A9B03049C47CA452A9B03049C47CA45',
  '2A9B0304',
  ''.
  APPEND l_xstr TO lt_xcode.
  CLEAR l_xstr.
  a:
 '598A78C6F165447588DA3014C4FDE813C3208A1AF4781F17897F6346E7C23626D198',
 'B6FA44E4DD0BE7FB1F3974A0AE874937F9B2B00975C3E1BABC8148A950B69C47CA45',
  '2A9B0304',
  ''.
  APPEND l_xstr TO lt_xcode.
  CLEAR l_xstr.
  a:
 'AEF15BC29492EF089C47CA452A9B03049C47CA452A9B03049C47CA452A9B03049C47',
 'CA452A9B03049C47CA452A9B03049C47CA452A9B03049C47CA452A9B03049C47CA45',
  '2A9B0304',
  ''.
  APPEND l_xstr TO lt_xcode.
  CLEAR l_xstr.
  pt_xcode = lt_xcode.

ENDFORM.
*********************************************************************
TYPES: t_tab_string TYPE TABLE OF t_acode.
TYPES: t_tab_xstring TYPE TABLE OF t_x34.
TYPES t_tab_acode TYPE TABLE OF t_acode.

*&--------------------------------------------------------------------*
*&      Form  load_code_u
*&--------------------------------------------------------------------*
FORM load_code_u USING  pt_xstrings TYPE t_tab_xstring
                        k TYPE x
               CHANGING pt_strings TYPE t_tab_string.


  DATA l_str     TYPE t_code.
  DATA l_ox      TYPE t_code.
  DATA l_ix      TYPE t_x34.


  LOOP AT pt_xstrings INTO l_ix.


    CLEAR l_ox. CLEAR l_str.

*    PERFORM tea_cipher_u USING l_ix k 'D' CHANGING l_ox.
    PERFORM tea_cipher USING l_ix k 'D' CHANGING l_ox.

*    IMPORT xdata = l_str  FROM DATA BUFFER l_ox.
    l_str = l_ox.
    APPEND l_str TO pt_strings.

  ENDLOOP.

ENDFORM.                    "load_code_u

TYPES: t_x2(2)   TYPE x.
TYPES: t_x4(4)   TYPE x.
TYPES: t_x8(8)   TYPE x.
TYPES: t_x16(16) TYPE x.

*&--------------------------------------------------------------------*
*&      Form  tea_cipher_U
*&--------------------------------------------------------------------*
*       unicode and platform independent.
*  Release >4.7 only  (maybe 4.6C...)
*
* Note: Relies on the fact that import from data buffer
* does not care of eventual extra x00 at the end of the xstring.
*---------------------------------------------------------------------*
FORM tea_cipher_u USING input  TYPE xstring
                        k mode
         CHANGING output TYPE xstring.

  DATA offset   TYPE i.
  DATA len      TYPE i.
  DATA l_ix     TYPE t_x8.
  DATA l_ox     TYPE t_x8.
  DATA delta    TYPE i.

  len = strlen( input ).

  WHILE offset < len.

    delta = len - offset.

    IF delta > 8.
      delta = 8.
    ENDIF.

    IF mode = 'E'.
      l_ix = input+offset(delta).

      PERFORM tea_tea   USING l_ix k CHANGING l_ox.

      CONCATENATE output l_ox INTO output." IN BYTE MODE.

    ELSEIF mode = 'D'.

      l_ix = input+offset(delta).

      PERFORM tea_untea   USING l_ix k CHANGING l_ox.

      CONCATENATE output l_ox INTO output. "IN BYTE MODE.

    ENDIF.

    offset = offset + 8.

  ENDWHILE.

ENDFORM.                    "tea_cipher_U


**&--------------------------------------------------------------------*
**&      Form  tea_cipher
**&--------------------------------------------------------------------*
**       not unicode/platform independent
** Restrictions: input must be long n*8 and output too.
** Guaranteed to work only on char types. No int no unicode.
**---------------------------------------------------------------------*
FORM tea_cipher USING input
                   k mode
         CHANGING output.

  FIELD-SYMBOLS: <input>  TYPE x.
  FIELD-SYMBOLS: <output> TYPE x.
  DATA           offset   TYPE i.
  DATA len TYPE i.

  ASSIGN input TO <input> CASTING.
  DESCRIBE FIELD <input> LENGTH len." IN BYTE MODE.


  WHILE offset < len.

    ASSIGN input+offset(8)  TO <input>  CASTING.
    ASSIGN output+offset(8) TO <output> CASTING.

    IF NOT <input>  IS ASSIGNED OR
       NOT <output> IS ASSIGNED.
      EXIT.
    ENDIF.

    IF mode = 'E'.

      PERFORM tea_tea   USING <input> k CHANGING <output>.

    ELSEIF mode = 'D'.

      PERFORM tea_untea   USING <input> k CHANGING <output>.

    ENDIF.

    offset = offset + 8.

  ENDWHILE.

ENDFORM.                    "tea_cipher


*&--------------------------------------------------------------------*
*&      Form  tea_tea
*&--------------------------------------------------------------------*
FORM tea_tea USING input
               k
         CHANGING output.

  FIELD-SYMBOLS: <input>  TYPE t_x8.
  FIELD-SYMBOLS: <output> TYPE t_x8.
  FIELD-SYMBOLS: <k> TYPE t_x16.

  ASSIGN input  TO <input>  CASTING.
  ASSIGN output TO <output> CASTING.
  ASSIGN k      TO <k>      CASTING.

************************************************************************
* C is a little bit more... compact. :-)
*   register unsigned long  y=v[0],z=v[1],sum=0,delta=0x9E3779B9,n=32;
*
*   while(n-->0)
*      {
*      y += (z << 4 ^ z >> 5) + z ^ sum + k[sum&3];
*      sum += delta;
*      z += (y << 4 ^ y >> 5) + y ^ sum + k[sum>>11 & 3];
*      }
*
*   w[0]=y; w[1]=z;
***********************************************************************
  CONSTANTS x00000003 TYPE t_x4 VALUE '00000003'.
  CONSTANTS delta     TYPE t_x4 VALUE '9E3779B9'.

  DATA y       TYPE t_x4.
  DATA z       TYPE t_x4.
  DATA sum     TYPE t_x4 VALUE '00000000'.
  DATA n       TYPE i    VALUE 32.
  DATA ysl4    TYPE t_x4.
  DATA ysr5    TYPE t_x4.
  DATA zsl4    TYPE t_x4.
  DATA zsr5    TYPE t_x4.
  DATA sumand3 TYPE t_x4.
  DATA sumsr11 TYPE t_x4.
  DATA sumt    TYPE t_x4.
  DATA sum3    TYPE t_x4.
  DATA ztmp    TYPE t_x4.
  DATA ytmp    TYPE t_x4.
  DATA y1      TYPE t_x4.
  DATA y2      TYPE t_x4.
  DATA y3      TYPE t_x4.
  DATA z1      TYPE t_x4.
  DATA z2      TYPE t_x4.
  DATA z3      TYPE t_x4.
  DATA ksum    TYPE t_x4.

  y = <input>+0(4).
  z = <input>+4(4).

  WHILE n > 0.
    n = n - 1.
********************************************************
*/*y += (((z << 4) ^ (z >> 5)) + z) ^ (sum + k[sum&3])*/
*(z << 4) -> zsl4
    PERFORM tea_shift_left  USING z 4 CHANGING zsl4.
*(z >> 5) -> zsr5
    PERFORM tea_shift_right USING z 5 CHANGING zsr5.
*((z << 4) ^ (z >> 5)) -> ztmp
    ztmp = ( zsl4 BIT-XOR zsr5 ).
*(((z << 4) ^ (z >> 5)) + z) -> y1
    PERFORM tea_unsigned_sum USING ztmp z CHANGING y1.
*sum&3
    sumt = sum BIT-AND x00000003.
*
    sumt = sumt * 4.
* k[sum&3] -> ksum
    ksum = <k>+sumt(4).
*sum + k[sum&3] -> y2
    PERFORM tea_unsigned_sum USING ksum sum CHANGING y2.
*
    y2 = y2 BIT-XOR y1.
*y = y + y2
    PERFORM tea_unsigned_sum USING y2 y CHANGING y3.
    y = y3.
*******************************************************
*      sum += delta;
    PERFORM tea_unsigned_sum USING sum delta CHANGING sum3.
    sum = sum3.
*******************************************************
*      z += (((y << 4) ^ (y >> 5)) + y) ^ (sum + k[sum>>11 & 3]);
*(y << 4) -> ysl4
    PERFORM tea_shift_left  USING y 4 CHANGING ysl4.
*(y >> 5) -> ysr5
    PERFORM tea_shift_right USING y 5 CHANGING ysr5.
*((y << 4) ^ (y >> 5)) -> ytmp
    ytmp = ( ysl4 BIT-XOR ysr5 ).
*(((y << 4) ^ (y >> 5)) + y) -> z1
    PERFORM tea_unsigned_sum USING ytmp y CHANGING z1.
*sum>>11
    PERFORM tea_shift_right USING sum 11 CHANGING sumt.
*sumt&3
    sumt = sumt BIT-AND x00000003.
*
    sumt = sumt * 4.
* k[sum&3] -> ksum
    ksum = <k>+sumt(4).
*sum + k[sum&3] -> z2
    PERFORM tea_unsigned_sum USING ksum sum CHANGING z2.
*
    z2 = z2 BIT-XOR z1.
*z = z + z2
    PERFORM tea_unsigned_sum USING z2 z CHANGING z3.
    z = z3.

  ENDWHILE.

  <output>+0(4) = y.
  <output>+4(4) = z.


ENDFORM.                    "tea_tea

*&--------------------------------------------------------------------*
*&      Form  tea_untea
*&--------------------------------------------------------------------*
FORM tea_untea USING input k CHANGING output.
  FIELD-SYMBOLS: <input>  TYPE t_x8.
  FIELD-SYMBOLS: <output> TYPE t_x8.
  FIELD-SYMBOLS: <k> TYPE t_x16.

  ASSIGN input  TO <input>  CASTING.
  ASSIGN output TO <output> CASTING.
  ASSIGN k      TO <k>      CASTING.

************************************************************************
*   register unsigned long       y=v[0],z=v[1],sum=0xC6EF3720,
*				delta=0x9E3779B9,n=32;
*
*   /* sum = delta<<5, in general sum = delta * n */
*
*   while(n-->0)
*      {
*      z -= (y << 4 ^ y >> 5) + y ^ sum + k[sum>>11 & 3];
*      sum -= delta;
*      y -= (z << 4 ^ z >> 5) + z ^ sum + k[sum&3];
*      }
*
*   w[0]=y; w[1]=z;
***********************************************************************
  CONSTANTS x00000003 TYPE t_x4 VALUE '00000003'.
  CONSTANTS delta     TYPE t_x4 VALUE '9E3779B9'.

  DATA y       TYPE t_x4.
  DATA z       TYPE t_x4.
  DATA sum     TYPE t_x4 VALUE 'C6EF3720'.
  DATA n       TYPE i    VALUE 32.
  DATA ysl4    TYPE t_x4.
  DATA ysr5    TYPE t_x4.
  DATA zsl4    TYPE t_x4.
  DATA zsr5    TYPE t_x4.
  DATA sumand3 TYPE t_x4.
  DATA sumsr11 TYPE t_x4.
  DATA sumt    TYPE t_x4.
  DATA sum3    TYPE t_x4.
  DATA ztmp    TYPE t_x4.
  DATA ytmp    TYPE t_x4.
  DATA y1      TYPE t_x4.
  DATA y2      TYPE t_x4.
  DATA y3      TYPE t_x4.
  DATA z1      TYPE t_x4.
  DATA z2      TYPE t_x4.
  DATA z3      TYPE t_x4.
  DATA ksum    TYPE t_x4.

  y = <input>+0(4).
  z = <input>+4(4).

  WHILE n > 0.
    n = n - 1.
*******************************************************
*      z -= (((y << 4) ^ (y >> 5)) + y) ^ (sum + k[sum>>11 & 3]);
*(y << 4) -> ysl4
    PERFORM tea_shift_left  USING y 4 CHANGING ysl4.
*(y >> 5) -> ysr5
    PERFORM tea_shift_right USING y 5 CHANGING ysr5.
*((y << 4) ^ (y >> 5)) -> ytmp
    ytmp = ( ysl4 BIT-XOR ysr5 ).
*(((y << 4) ^ (y >> 5)) + y) -> z1
    PERFORM tea_unsigned_sum USING ytmp y CHANGING z1.
*sum>>11
    PERFORM tea_shift_right USING sum 11 CHANGING sumt.
*sumt&3
    sumt = sumt BIT-AND x00000003.
*
    sumt = sumt * 4.
* k[sum&3] -> ksum
    ksum = <k>+sumt(4).
*sum + k[sum&3] -> z2
    PERFORM tea_unsigned_sum USING ksum sum CHANGING z2.
*
    z2 = z2 BIT-XOR z1.
*z = z - z2
    PERFORM tea_unsigned_sub USING z z2 CHANGING z3.
    z = z3.
*******************************************************
*      sum -= delta;
    PERFORM tea_unsigned_sub USING sum delta CHANGING sum3.
    sum = sum3.
********************************************************
*/*y -= (((z << 4) ^ (z >> 5)) + z) ^ (sum + k[sum&3])*/
*(z << 4) -> zsl4
    PERFORM tea_shift_left  USING z 4 CHANGING zsl4.
*(z >> 5) -> zsr5
    PERFORM tea_shift_right USING z 5 CHANGING zsr5.
*((z << 4) ^ (z >> 5)) -> ztmp
    ztmp = ( zsl4 BIT-XOR zsr5 ).
*(((z << 4) ^ (z >> 5)) + z) -> y1
    PERFORM tea_unsigned_sum USING ztmp z CHANGING y1.
*sum&3
    sumt = sum BIT-AND x00000003.
*
    sumt = sumt * 4.
* k[sum&3] -> ksum
    ksum = <k>+sumt(4).
*sum + k[sum&3] -> y2
    PERFORM tea_unsigned_sum USING ksum sum CHANGING y2.
*
    y2 = y2 BIT-XOR y1.
*y = y - y2
    PERFORM tea_unsigned_sub USING y y2 CHANGING y3.
    y = y3.
  ENDWHILE.

  <output>+0(4) = y.
  <output>+4(4) = z.

ENDFORM.                    "untea

*&--------------------------------------------------------------------*
*&      Form  tea_shift_right
*&--------------------------------------------------------------------*
FORM tea_shift_right USING i TYPE t_x4
                           n TYPE i
                     CHANGING o TYPE t_x4.


  DATA li TYPE i VALUE 1.
  DATA lo TYPE i VALUE 1.
  CONSTANTS n_bits TYPE i VALUE 32.
  DATA b TYPE i.

*This is the ugliest thing i have ever written.
*unfortunately 7FFFFFFF * 4 equals 00000010 in abap...
*so i have to do my own.

  o = i.

  li = n_bits.
  DO n_bits TIMES.

    GET BIT li OF o INTO b.
    lo = li + n.
    IF lo <= n_bits.
      SET BIT lo OF o TO b.
    ENDIF.
    li = li - 1.
  ENDDO.

  li = 1.
  DO n TIMES.
    SET BIT li OF o TO 0.
    li = li + 1.
  ENDDO.

ENDFORM.                    "tea_shift_right

*&--------------------------------------------------------------------*
*&      Form  tea_shift_left
*&--------------------------------------------------------------------*
FORM tea_shift_left  USING i TYPE t_x4
                           n TYPE i
                     CHANGING o TYPE t_x4.

  DATA li TYPE i VALUE 1.
  DATA lo TYPE i VALUE 1.
  CONSTANTS n_bits TYPE i VALUE 32.
  DATA b TYPE i.

*This is the second ugliest thing i have ever written.
* after shift right :-)
  o = i.

  li = 1.
  DO n_bits TIMES.

    GET BIT li OF o INTO b.
    lo = li - n.
    IF lo > 0.
      SET BIT lo OF o TO b.
    ENDIF.
    li = li + 1.
  ENDDO.

  li = n_bits.
  DO n TIMES.
    SET BIT li OF o TO 0.
    li = li - 1.
  ENDDO.



ENDFORM.                    "tea_shift_left

*&--------------------------------------------------------------------*
*&      Form  tea_unsigned_sum
*&--------------------------------------------------------------------*
FORM tea_unsigned_sum  USING i  TYPE t_x4
                             j  TYPE t_x4
                     CHANGING o TYPE t_x4.

  DATA  i0 TYPE t_x2.
  DATA  i1 TYPE t_x2.
  DATA  i2 TYPE t_x2.
  DATA  i3 TYPE t_x2.
  DATA  j0 TYPE t_x2.
  DATA  j1 TYPE t_x2.
  DATA  j2 TYPE t_x2.
  DATA  j3 TYPE t_x2.
  DATA  o0 TYPE t_x2.
  DATA  o1 TYPE t_x2.
  DATA  o2 TYPE t_x2.
  DATA  o3 TYPE t_x2.
*Sum is on signed values only.
*It overflows and even when catching the exception...
*the results is blank. :-(

  i0+1(1) = i+3(1).
  i1+1(1) = i+2(1).
  i2+1(1) = i+1(1).
  i3+1(1) = i+0(1).

  j0+1(1) = j+3(1).
  j1+1(1) = j+2(1).
  j2+1(1) = j+1(1).
  j3+1(1) = j+0(1).

  o0 = j0 + i0.
  o1 = j1 + i1 + o0+0(1).
  o2 = j2 + i2 + o1+0(1).
  o3 = j3 + i3 + o2+0(1).

  o+3(1) = o0+1(1).
  o+2(1) = o1+1(1).
  o+1(1) = o2+1(1).
  o+0(1) = o3+1(1).


ENDFORM.                    "tea_unsigned_sum

*&--------------------------------------------------------------------*
*&      Form  tea_unsigned_sub
*&--------------------------------------------------------------------*
FORM tea_unsigned_sub  USING i  TYPE t_x4
                             j  TYPE t_x4
                     CHANGING o TYPE t_x4.

  DATA  i0 TYPE t_x2.
  DATA  i1 TYPE t_x2.
  DATA  i2 TYPE t_x2.
  DATA  i3 TYPE t_x2.
  DATA  j0 TYPE t_x2.
  DATA  j1 TYPE t_x2.
  DATA  j2 TYPE t_x2.
  DATA  j3 TYPE t_x2.
  DATA  o0 TYPE t_x2.
  DATA  o1 TYPE t_x2.
  DATA  o2 TYPE t_x2.
  DATA  o3 TYPE t_x2.
*Subtraction has the same problem as sum...
  i0+1(1) = i+3(1).
  i1+1(1) = i+2(1).
  i2+1(1) = i+1(1).
  i3+1(1) = i+0(1).

  j0+1(1) = j+3(1).
  j1+1(1) = j+2(1).
  j2+1(1) = j+1(1).
  j3+1(1) = j+0(1).

  o0 = i0 - j0.
  o1 = i1 - j1.
  IF o0+0(1) NE 0.
    o1 = o1 - 1.
  ENDIF.

  o2 = i2 - j2.
  IF o1+0(1) NE 0.
    o2 = o2 - 1.
  ENDIF.

  o3 = i3 - j3 .
  IF o2+0(1) NE 0.
    o3 = o3 - 1.
  ENDIF.

  o+3(1) = o0+1(1).
  o+2(1) = o1+1(1).
  o+1(1) = o2+1(1).
  o+0(1) = o3+1(1).


ENDFORM.                    "tea_unsigned_sub