#!/bin/csh

# Syntax: Create_Seed  file1  file2  file3  > outputfile
#
#  file1, file2 contain the two Key Primes, p and q
#  file3        contains an initial starting point from which seed is generated
#  stdout       will be written with an approved seed -- a quadratic residue
#                       modulo p*q

if ($#argv != 3) then
   echo "Usage: " $0 " keyfile1  keyfile2  initializer"
   exit 1
endif

if ( ! -e $1 ) then
   echo "Cant find file " $1
   exit 1
endif

if ( ! -e $2 ) then
   echo "Cant find file " $2
   exit 1
endif

if ( ! -e $3 ) then
   echo "Cant find file " $3
   exit 1
endif

# cook up a name for a temporary workfile
set tf = ./seed_ugh.$$

# first, grab the bc program that calculates quadratic residues
cp ./find_residue_bc $tf
chmod 777 $tf

# grab the first Blum integer from keyfile1
echo ' p = \' >> $tf
cat $1 >> $tf

# grab the second Blum integer from keyfile2
echo ' q = \' >> $tf
cat $2 >> $tf

# grab the initial starting point for the seed from initializerfile
echo ' i = \' >> $tf
cat $3 >> $tf

# tell bc to execute the quadradic-redidue-seedfinder routine named s
echo "s(p,q,i)" >> $tf

# fire up bc.  Output goes to stdout as desired.
bc < $tf

# clean up the excess
rm $tf