#!/usr/bin/bash

#***************************************************************************
# This file is part of the CRYPTO BONE
# File     : safewebdropcrosscontact (client) 
# Version  : 1.6 (ALL-IN-ONE)
# License  : BSD
# Date     : 12 May 2023
# Contact  : Please send enquiries and bug-reports to innovation@senderek.ie
#
#
# Copyright (c) 2015-2023
#	Ralf Senderek, Ireland.  All rights reserved. (https://senderek.ie)
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
# 3. All advertising materials mentioning features or use of this software
#    must display the following acknowledgement:
#	   This product includes software developed by Ralf Senderek.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND  ANY EXPRESS OR 
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE  IMPLIED WARRANTIES 
# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  
# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 
# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 
# OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 
# WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
# POSSIBILITY OF SUCH DAMAGE.
#
#****************************************************************************

# Parameter: 
# $1 is the sender (me%myhost.com)   
# $2 is the cross ID ID
# $3 is the cross SERVER
# $4 is the SECRET, used to generate the first hashvalue


# ID is sending a signed contact request to the cross SERVER for user IDID

#----------------------------------------------------#
# load functions and global variables
. /usr/lib/cryptobone/safewebdrop/bin/client-functions

REQ=$RAM/contactrequest
MSG=$RAM/contactmessage
SOCK="/usr/lib/cryptobone/secrets.sock"

# the following two elements are used for signing the requests
PASS=$(/usr/bin/echo "get-element webdropsecret" | /usr/bin/socat -t15 - UNIX-connect:$SOCK 2> /dev/null)
ID=$(/usr/bin/echo "get-element webdropuser" | /usr/bin/socat -t15 - UNIX-connect:$SOCK 2> /dev/null)

SENDER="$1"   
CONTACTID="$2"
CONTACTHOST="$3"
SECRET="$4"


log "---cross contact---"
### log "GOTTEN $1 $2 $3 $4"

if (( $# == 4 )) ; then
     if [[ ${PASS} ]] && [[ ${ID} ]] ; then
          # phase 1: send CONTACT request
          CHALLENGE=$(/usr/bin/curl https://${CONTACTHOST}/cgi-bin/safewebdropcrosscontact?${CONTACTID}\&CONTACT 2>/dev/null)
          if (( ${#CHALLENGE} != 64 )) ; then
               log "I: $CHALLENGE no challenge EXIT "
     	       exit 2
          fi
          log "I:  ${ID} CHL=${CHALLENGE}" 

          # phase 2: create one valid permission request
          
	  /usr/bin/rm -f ${REQ}.hash.sig ${MSG} 2> /dev/null
          # user:sender:request:hashsig:sender-pubkey
          /usr/bin/echo -n "${CHALLENGE}:" > ${REQ}
          /usr/bin/echo -n "${SENDER}:" >> ${REQ}

	  # store a different hash for B ([[B%S2, A%S, secret]])
          /usr/bin/echo -n "${CONTACTID}%${CONTACTHOST}:" > ${MSG}
          /usr/bin/echo -n "${SENDER}:" >> ${MSG}
          /usr/bin/echo -n "${SECRET}" >> ${MSG}
	  HASHVALUE=$(/usr/bin/cat ${MSG} | /usr/bin/sha256sum | /usr/bin/cut -c-64 )
          /usr/bin/echo -n "${HASHVALUE}" >> ${REQ}

          # generate a hash of the request
          generate_requesthash

          KEY=/usr/lib/cryptobone/safewebdrop/pubkey.pem
	  # base64 encode the public key
          /usr/bin/base64 --wrap=0 ${KEY} > ${KEY}.b64
          PUBKEY=$(/usr/bin/cat ${KEY}.b64)
          
	  # and send it
          if (( ${#SIG} > 10 )) ; then
               /usr/bin/sleep 1
	       REQUEST=$(/usr/bin/cat ${REQ})
               OK=$(/usr/bin/curl https://${CONTACTHOST}/cgi-bin/safewebdropcrosscontact?${CONTACTID}\&${REQUEST}\&${SIG}\&${PUBKEY} 2> /dev/null)
     	  log "II: $ID  ${#OK} bytes received" 
               if [[ "${OK}" = "OK" ]]  ; then
     	            log "III: OK valid cross contact sent for ${CONTACTID}"
     	       fi
          else
               log "II: no file ${MSG}"
          fi
     fi
else
     log "not enough parameter"
     exit 1
fi
log "--- end cross contact ---"
exit 0