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-- S_BOX_FUNCTION.lnt -- 1.11 -- 2015/09/11 11:04:16 -- (C) Wendelin Serwe
-------------------------------------------------------------------------------

module S_BOX_FUNCTIONS (TYPES) is

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-- data types defining a two-dimensional array to encode the S-boxes

type ROW is
   array [0..15] of NAT
end type

type S_BOX_ARRAY is
   array [0..3] of ROW
end type

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function GET_ROW (X: BIT6) : NAT is
   return BIT2_TO_NAT (1AND6 (X))
end function

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function GET_COLUMN (X: BIT6) : NAT is
   return BIT4_TO_NAT (2TO5 (X))
end function

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function S1 : S_BOX_ARRAY is
   return
      S_BOX_ARRAY
        (ROW (14,  4, 13,  1,  2, 15, 11,  8,  3, 10,  6, 12,  5,  9,  0,  7),
         ROW ( 0, 15,  7,  4, 14,  2, 13,  1, 10,  6, 12, 11,  9,  5,  3,  8),
         ROW ( 4,  1, 14,  8, 13,  6,  2, 11, 15, 12,  9,  7,  3, 10,  5,  0),
         ROW (15, 12,  8,  2,  4,  9,  1,  7,  5, 11,  3, 14, 10,  0,  6, 13))
end function

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function S2 : S_BOX_ARRAY is
   return
      S_BOX_ARRAY 
        (ROW (15,  1,  8, 14,  6, 11,  3,  4,  9,  7,  2, 13, 12,  0,  5, 10),
         ROW ( 3, 13,  4,  7, 15,  2,  8, 14, 12,  0,  1, 10,  6,  9, 11,  5),
         ROW ( 0, 14,  7, 11, 10,  4, 13,  1,  5,  8, 12,  6,  9,  3,  2, 15),
         ROW (13,  8, 10,  1,  3, 15,  4,  2, 11,  6,  7, 12,  0,  5, 14,  9))
end function

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function S3 : S_BOX_ARRAY is
   return
      S_BOX_ARRAY 
        (ROW (10,  0,  9, 14,  6,  3, 15,  5,  1, 13, 12,  7, 11,  4,  2,  8),
         ROW (13,  7,  0,  9,  3,  4,  6, 10,  2,  8,  5, 14, 12, 11, 15,  1),
         ROW (13,  6,  4,  9,  8, 15,  3,  0, 11,  1,  2, 12,  5, 10, 14,  7),
         ROW ( 1, 10, 13,  0,  6,  9,  8,  7,  4, 15, 14,  3, 11,  5,  2, 12))
end function

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function S4 : S_BOX_ARRAY is
   return
      S_BOX_ARRAY 
        (ROW ( 7, 13, 14,  3,  0,  6,  9, 10,  1,  2,  8,  5, 11, 12,  4, 15),
         ROW (13,  8, 11,  5,  6, 15,  0,  3,  4,  7,  2, 12,  1, 10, 14,  9),
         ROW (10,  6,  9,  0, 12, 11,  7, 13, 15,  1,  3, 14,  5,  2,  8,  4),
         ROW ( 3, 15,  0,  6, 10,  1, 13,  8,  9,  4,  5, 11, 12,  7,  2, 14))
end function

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function S5 : S_BOX_ARRAY is
   return
      S_BOX_ARRAY 
        (ROW ( 2, 12,  4,  1,  7, 10, 11,  6,  8,  5,  3, 15, 13,  0, 14,  9),
         ROW (14, 11,  2, 12,  4,  7, 13,  1,  5,  0, 15, 10,  3,  9,  8,  6),
         ROW ( 4,  2,  1, 11, 10, 13,  7,  8, 15,  9, 12,  5,  6,  3,  0, 14),
         ROW (11,  8, 12,  7,  1, 14,  2, 13,  6, 15,  0,  9, 10,  4,  5,  3))
end function

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function S6 : S_BOX_ARRAY is
   return
      S_BOX_ARRAY
        (ROW (12,  1, 10, 15,  9,  2,  6,  8,  0, 13,  3,  4, 14,  7,  5, 11),
	 ROW (10, 15,  4,  2,  7, 12,  9,  5,  6,  1, 13, 14,  0, 11,  3,  8),
	 ROW ( 9, 14, 15,  5,  2,  8, 12,  3,  7,  0,  4, 10,  1, 13, 11,  6),
	 ROW ( 4,  3,  2, 12,  9,  5, 15, 10, 11, 14,  1,  7,  6,  0,  8, 13))
end function

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function S7 : S_BOX_ARRAY is
   return
      S_BOX_ARRAY
        (ROW ( 4, 11,  2, 14, 15,  0,  8, 13,  3, 12,  9,  7,  5, 10,  6,  1),
	 ROW (13,  0, 11,  7,  4,  9,  1, 10, 14,  3,  5, 12,  2, 15,  8,  6),
	 ROW ( 1,  4, 11, 13, 12,  3,  7, 14, 10, 15,  6,  8,  0,  5,  9,  2),
	 ROW ( 6, 11, 13,  8,  1,  4, 10,  7,  9,  5,  0, 15, 14,  2,  3, 12))
end function

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function S8 : S_BOX_ARRAY is
   return
      S_BOX_ARRAY
        (ROW (13,  2,  8,  4,  6, 15, 11,  1, 10,  9,  3, 14,  5,  0, 12,  7),
	 ROW ( 1, 15, 13,  8, 10,  3,  7,  4, 12,  5,  6, 11,  0, 14,  9,  2),
	 ROW ( 7, 11,  4,  1,  9, 12, 14,  2,  0,  6, 10, 13, 15,  3,  5,  8),
	 ROW ( 2,  1, 14,  7,  4, 10,  8, 13, 15, 12,  9,  0,  3,  5,  6, 11))
end function

end module