#! /usr/sepp/bin/perl -w

############################################################
## Copyright: 2011 Integrated Sytems Laboratory, ETH Zurich
##            http://www.iis.ee.ethz.ch/~sha3
############################################################
use strict;

# v0.1 - muheim@ee.ethz.ch - Fri Aug 12 09:31:00 CEST 2011
# - script to generate the vectors from the gen_sha3_stimuli
#   copy from ethz_keccak_stimuli.pl v0.3

# make sure the lengths are ok later on

## CONSTANTS
my $HASH_BLOCK_SIZE= 512;  # Keccak SHA-256 version
my $MIN_PADDING_SIZE= 80;  # this is not completely correct. Min size is 
                           # 1 + 64 but it is so much easier to generate 16 + 64

## let us extract the information first 
my @L;  # length array
my @M;  # message array
my @D;  # digest array

# steal all the information
# Note: if one of the entries MD, Len, Msg is missing trouble will arise

open (S, "< expresp.txt");
while (S){
   push (@L,$1) if (/^\s*Len\s*=\s*([0-9]+)/i);
   push (@M,$1) if (/^\s*Msg\s*=\s*([0-9A-F]+)/i);
   push (@D,$1) if (/^\s*MD\s*=\s*([0-9A-F]+)/i);
}
close(S);


  my $date= `date`;
  chomp ($date);

print <<"BUGU";
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% Test vectors for ETHZ BLAKE 
%%   generated by ethz_blake_stimuli.pl
%%   on $date
%% 
BUGU

## loop over all read messages 
for my $i (0..$#L){
 ## how many blocks will we need
 my $num_blocks=int (($L[$i] + $MIN_PADDING_SIZE - 1) / $HASH_BLOCK_SIZE) +1; 

 ## now let us determine the padding
 ## It is very easy to calculate this provided the pad size is at least 16
 ## it is a restriction at the moment but it works easily.. 
 ## for other lengths we need a more elaborate code.. 
 my $zero_cnt = (($HASH_BLOCK_SIZE * $num_blocks) - $L[$i] - $MIN_PADDING_SIZE) / 8;
 my $pad = "80"."00" x $zero_cnt."01";

# my $len = unpack ("H16", pack("N2",$L[$i]));
 my $len = sprintf("%016x\n", $L[$i]);
 $pad=$pad.$len;

#print $L[$i]." ".$len." ".$num_blocks." ".$zero_cnt."\n";
#print "$zero_cnt = (($HASH_BLOCK_SIZE * $num_blocks) - $L[$i] - $MIN_PADDING_SIZE)\n";


## these two are so that the reports look cute
my $pretty_i   = $i + 1;
my $pretty_len = $#L + 1;

# comment character is '%' n the testbench

print <<"BUGU";
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% vector $pretty_i of $pretty_len
%% Length  = $L[$i], Number of $HASH_BLOCK_SIZE bit blocks = $num_blocks, Padding = $pad
%% Message = $M[$i]
%% Digest  = $D[$i]
BUGU

 ## add the pad and the length to the message
 $M[$i]=$M[$i].$pad;


 ## now loop over number of blocks
 for my $j (1..$num_blocks){
   ## this is the part of the message that goes out
   my $sub=substr($M[$i],($j-1)*($HASH_BLOCK_SIZE/4),($HASH_BLOCK_SIZE/4));
 
   ## generate the output
   print unpack("B*",pack("H*",$sub))." ";            # this is the block input
   ## are we in the last block 
   if ($j eq $num_blocks){
     print "1 ".unpack("B*", pack("N2",$L[$i]))." ";
     print unpack("B*",pack("H*",$D[$i]))."\n";  # set last and compare
   }
   else{
     print "0 ".unpack("B*", pack("N2", $j * 512 ))." ".'-' x 256 . "\n";                    # don't set last and don't care

   }
 }
}