#!/usr/bin/env bash

# Usage:       ./extract-and-index-evolution-mail-storage <EWF image>
#                or
#              bash extract-and-index-evolution-mail-storage <EWF image>
# Description: (see scriptname!)
# Author:      Patrick Neumann (patrick@neumannsland.de)
# Version:     0.9
# Date:        07.04.2019
# License:     GPL3
# Warranty:    This program is distributed WITHOUT ANY WARRANTY
# Todo:        -
# Tests:       Forensik Workstation(s):
#                - macOS 10.13.6 + TSK 4.6.5 (Homebrew) + mu 1.0 (Homebrew) 
#                - ArchLinux + TSK 4.6.5 + mu 1.0 (AUR)
#              Image(s):
#                - VirtualBox VM with Linux Mint 19.1 + Evolution 3.28.5

#-------------------------------------------------------------------------------
# Simple checks for dependencies:
#-------------------------------------------------------------------------------
which ifind > /dev/null || ( echo "Please install sleuthkit!" ; exit 1 )
which mu > /dev/null || ( echo "Please install mu!" ; exit 1 )

#=== FUNCTION ==================================================================
# NAME: usage
# DESCRIPTION: Display help.
# PARAMETERS: -
#===============================================================================
usage () {
  printf "Usage:\n"
  printf "  $0 <EWF image>\n"
}

#-------------------------------------------------------------------------------
# Check for one param:
#-------------------------------------------------------------------------------
if [ "${#}" -ne 1 ]; then
  echo "Please provide exactly one parameter!"
  echo
  usage
	exit 2
fi

#=== CONFIGURATION (params) ====================================================
#-------------------------------------------------------------------------------
# Check and set image:
#-------------------------------------------------------------------------------
if ! file "${1}" | grep -F "EWF" > /dev/null ; then
  echo "Please provide EWF image!"
  echo
	usage
  exit 3
fi
readonly IMG="${1}"

#=== CONFIGURATION (dynamic) ===================================================
#-------------------------------------------------------------------------------
# Find and set home directory:
#-------------------------------------------------------------------------------
offsets="$( mmls -aM "${IMG}" \
  | awk '/^[[:digit:]]{3}:/ { print $3; }' \
  | sed 's/0*//' )"
for offset in ${offsets} ; do
  if fsstat -o "${offset}" "${IMG}" \
    | grep -E "^Last mounted on: /home$" > /dev/null
  then
    home=""
    readonly S_PRE=""
    readonly T_PRE="./recovered/home"
    readonly OFS="${offset}"
	elif fsstat -o "${offset}" "${IMG}" \
    | grep -E "^Last mounted on: /$" > /dev/null
  then
    home="$( ifind -o "${offset}" -n "/home" "${IMG}" )"
		if [ "${home}" != "File not found" ] ; then
      readonly S_PRE="/home"
	    readonly T_PRE="./recovered"
	    readonly OFS="${offset}"
		fi
	else
		echo "/home not found!"
		echo
		echo "Hint:"
		echo "  1.: assemble RAID and/or LVM"
		echo "  2.: ewfacquire the file system of /home"
    echo "  3.: use that image with ${0}"
    exit 4
	fi
done

#=== CONFIGURATION (user) ======================================================
#-------------------------------------------------------------------------------
# Select user:
#-------------------------------------------------------------------------------
printf "Please select a user:\n"
users="$( fls -o "${OFS}" "${IMG}" "${home}" | awk '{ print $NF; }' )"
select user in ${users} ; do
  if [ -n "${user}" ] ; then
    break
  fi
done

#=== CONFIGURATION (static) ====================================================
readonly LOCAL=".local/share/evolution/mail"
readonly CACHE=".cache/evolution/mail"
DIRS="${S_PRE}/${user}/${LOCAL}/"
readonly DIRS="${DIRS} ${S_PRE}/${user}/${CACHE}/"

#-------------------------------------------------------------------------------
# ... magic ...
#-------------------------------------------------------------------------------
for DIR in ${DIRS} ; do
  #-----------------------------------------------------------------------------
  # Store inode of DIR as start:
  #-----------------------------------------------------------------------------
  start="$( ifind -o "${OFS}" -n "${DIR}" "${IMG}" )"

  if [ "${start}" = "File not found" ] ; then
		echo "${DIR} not found!"
		continue
  fi
  #-----------------------------------------------------------------------------
  # Store directory paths recursively under start pipe separated as dirs:
  #-----------------------------------------------------------------------------
  dirs="$( fls -o "${OFS}" -u -D -r -m "${DIR}" "${IMG}" "${start}" )"

  #-----------------------------------------------------------------------------
  # Create target folder structure recursively:
  #-----------------------------------------------------------------------------
  for dir in ${dirs} ; do
    path="$( echo "${dir}" | cut -d "|" -f 2 )"

    # the subfolder between "cur" and the mail kill the RFC
    if ! echo ${path} \
      | grep -E ".*/\.cache/evolution/mail/.*/folders/.*/cur/.*" > /dev/null
    then
      if ! [ -d "${path}" ] ; then
        mkdir -p "${T_PRE}${path}"
      fi
    fi
  done

  #-----------------------------------------------------------------------------
  # Store file names recursively under start pipe separated as files:
  #-----------------------------------------------------------------------------
  files="$( fls -o "${OFS}" -u -F -r -m "${DIR}" "${IMG}" "${start}" )"

  #-----------------------------------------------------------------------------
  # Extract files recursively into target folder(s):
  #-----------------------------------------------------------------------------
  for file in ${files} ; do
    inode="$( echo "${file}" | cut -d "|" -f 3 )"
    name="$( echo "${file}" | cut -d "|" -f 2 )"

    if ! echo ${name} \
      | grep -E ".*/\.cache/evolution/mail/.*/folders/.*/cur/.*/.*" > /dev/null
    then
      icat -o "${OFS}" "${IMG}" "${inode}" > "${T_PRE}${name}"
    else
      # replace the last slash with a hyphen
      icat -o "${OFS}" "${IMG}" "${inode}" > "${T_PRE}${name%/*}-${name##*/}"
    fi
  done
done

#-------------------------------------------------------------------------------
# Index the local mail storage:
#-------------------------------------------------------------------------------
if [ -d "${T_PRE}${S_PRE}/${user}/${LOCAL}" ] ; then
  mu index --quiet --muhome=./mu --maildir="${T_PRE}${S_PRE}/${user}/${LOCAL}"
fi

#-------------------------------------------------------------------------------
# Index the external mail storage(s):
#-------------------------------------------------------------------------------
accounts="$( find -E "${T_PRE}${S_PRE}/${user}/${CACHE}" -type d -depth 1 \
  -iregex ".*/[[:xdigit:]]{40}" -exec basename '{}' \; )"
for account in ${accounts} ; do
  folders="$( find -E "${T_PRE}${S_PRE}/${user}/${CACHE}/${account}/folders" \
    -type d -depth 1 -exec basename '{}' \; )"
  for folder in ${folders} ; do
    mu index --quiet --muhome=./mu \
      --maildir="${T_PRE}${S_PRE}/${user}/${CACHE}/${account}/folders/${folder}"
	done
done

exit 0