Subversion Repositories bluespec_md6

//----------------------------------------------------------------------//

// The MIT License

//

// Copyright (c) 2008 Kermin Fleming, kfleming@mit.edu

//

// Permission is hereby granted, free of charge, to any person

// obtaining a copy of this software and associated documentation

// files (the "Software"), to deal in the Software without

// restriction, including without limitation the rights to use,

// copy, modify, merge, publish, distribute, sublicense, and/or sell

// copies of the Software, and to permit persons to whom the

// Software is furnished to do so, subject to the following conditions:

//

// The above copyright notice and this permission notice shall be

// included in all copies or substantial portions of the Software.

//

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES

// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND

// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT

// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,

// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING

// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR

// OTHER DEALINGS IN THE SOFTWARE.

//----------------------------------------------------------------------//

import Vector::*;

import MD6Parameters::*;

import MD6Types::*;

import CompressionFunctionTypes::*;

import CompressionFunctionParameters::*;

// The following are magic, externally defined parameters in MD6

// Other important parameters are derived from them.

// These parameters are used solely within the compression

// function.

// This set of functions determines the locations of the filter taps

// these index into the constant array given in appendix C of the spec.

// TODO: kfleming - these are currently constant functions.

function Integer determineT0();

  Integer returnValue = 0;

  if((valueof(MD6_n) == 89) && (valueof(MD6_c) == 16))

    begin

      returnValue = 17;

    end

  else if((valueof(MD6_n) == 178) && (valueof(MD6_c) == 32))

    begin

      returnValue = 33;

    end

  else

    begin

      let err = error("T0 not defined");

    end

  return valueof(MD6_n)-returnValue;

endfunction

function Integer determineT1();

  Integer returnValue = 0;

  if((valueof(MD6_n) == 89) && (valueof(MD6_c) == 16))

    begin

      returnValue = 18;

    end

  else if((valueof(MD6_n) == 178) && (valueof(MD6_c) == 32))

    begin

      returnValue = 35;

    end

  else

    begin

      let err = error("T1 not defined");

    end

  return valueof(MD6_n)-returnValue;

endfunction

function Integer determineT2();

  Integer returnValue = 0;

  if((valueof(MD6_n) == 89) && (valueof(MD6_c) == 16))

    begin

      returnValue = 21;

    end

  else if((valueof(MD6_n) == 178) && (valueof(MD6_c) == 32))

    begin

      returnValue = 49;

    end

  else

    begin

      let err = error("T2 not defined");

    end

  return valueof(MD6_n)-returnValue;

endfunction

function Integer determineT3();

  Integer returnValue = 0;

  if((valueof(MD6_n) == 89) && (valueof(MD6_c) == 16))

    begin

      returnValue = 31;

    end

  else if((valueof(MD6_n) == 178) && (valueof(MD6_c) == 32))

    begin

      returnValue = 53;

    end

  else

    begin

      let err = error("T3 not defined");

    end

  return valueof(MD6_n)-returnValue;

endfunction

function Integer determineT4();

  Integer returnValue = 0;

  if((valueof(MD6_n) == 89) && (valueof(MD6_c) == 16))

    begin

      returnValue = 67;

    end

  else if((valueof(MD6_n) == 178) && (valueof(MD6_c) == 32))

    begin

      returnValue = 111;

    end

  else

    begin

      let err = error("T4 not defined");

    end

  return valueof(MD6_n)-returnValue;

endfunction

function Integer determineT5();

  return 0;

endfunction

// This function returns the shift amounts.  The argument is the step

// index.

function ShiftFactor shiftIndexR(Bit#(4) index);

  if(valueof(MD6_WordWidth) == 64)

    begin

      return c64ShiftR[index];

    end

  else if(valueof(MD6_WordWidth) == 32)

    begin

      return c32ShiftR[index];

    end

  else if(valueof(MD6_WordWidth) == 16)

    begin

      return c16ShiftR[index];

    end

  else if(valueof(MD6_WordWidth) == 8)

    begin

      return c8ShiftR[index];

    end

  else

    begin

      return 0;

    end

endfunction

function ShiftFactor shiftIndexL(Bit#(4) index);

  if(valueof(MD6_WordWidth) == 64)

    begin

      return c64ShiftL[index];

    end

  else if(valueof(MD6_WordWidth) == 32)

    begin

      return c32ShiftL[index];

    end

  else if(valueof(MD6_WordWidth) == 16)

    begin

      return c16ShiftL[index];

    end

  else if(valueof(MD6_WordWidth) == 8)

    begin

      return c8ShiftL[index];

    end

  else

    begin

      return 0;

    end

endfunction

function Vector#(MD6_u, MD6Word) makeControlWord(Round rounds,

                              TreeHeight maxTreeHeight,

                              LastCompression lastCompression,

                              PaddingBits paddingBits,

                              KeyLength keyLength,

                              DigestLength digestLength)

  provisos(Bits#(MD6Word, md6_size));

  Bit#(64) controlWord = {4'b0000,rounds,maxTreeHeight,lastCompression,

          paddingBits,keyLength, digestLength};

  MD6Word controlArray[valueof(MD6_u)];

  for(Integer i = 0; i < valueof(MD6_u); i = i + 1)

    begin

      controlArray[fromInteger(i)] = controlWord[(i+1)*valueof(md6_size)-1:i*valueof(md6_size)];

    end

  Vector#(MD6_u, MD6Word) controlVector = arrayToVector(controlArray);

  return controlVector;

endfunction