#!/bin/bash

base58=({1..9} {A..H} {J..N} {P..Z} {a..k} {m..z})
bitcoinregex="^[$(printf "%s" "${base58}")]{34}$"

decodeBase58() {
    local s=$1
    for i in {0..57}
    do s="${s//${base58}/ $i}"
    done
    dc <<< "16o0d${s// /+58*}+f"
}

encodeBase58() {
    # 58 = 0x3A
    bc <<<"ibase=16; n=${1^^}; while(n>0) { n%3A ; n/=3A }" |
    tac |
    while read n
    do echo -n ${base58[n]}
    done
}

checksum() {
    xxd -p -r <<<"$1" |
    openssl dgst -sha256 -binary |
    openssl dgst -sha256 -binary |
    xxd -p -c 80 |
    head -c 8
}

checkBitcoinAddress() {
    if [[ "$1" =~ $bitcoinregex ]]
    then
        h=$(decodeBase58 "$1")
        checksum "00${h::${#h}-8}" |
        grep -qi "^${h: -8}$"
    else return 2
    fi
}

hash160() {
    openssl dgst -sha256 -binary |
    openssl dgst -rmd160 -binary |
    xxd -p -c 80
}

hash160ToAddress() {
    printf "%34s\n" "$(encodeBase58 "00$1$(checksum "00$1")")" |
    sed "y/ /1/"
}

hash256ToAddress() {
#printf "80$1$(checksum "80$1")"
    printf "%34s\n" "$(encodeBase58 "80$1$(checksum "80$1")")" |
    sed "y/ /1/"
}

publicKeyToAddress() {
    hash160ToAddress $(
    openssl ec -pubin -pubout -outform DER |
    tail -c 65 |
    hash160
    )
}

privateKeyToWIF() {
    hash256ToAddress $(openssl ec -text -noout -in data.pem | head -5 | tail -3 | fmt -120 | sed 's/[: ]//g')
   
}

openssl  ecparam -genkey -name secp256k1 | tee data.pem &>/dev/null

sleep 3

echo " "
echo "BITCOINS OFF-THE-GRID (BOTG) : A VERY SECURE SAVINGS ACCOUNT!"
echo " "
echo "THE FOLLOWING WILL BE THE PRIVATE HEX KEY NEEDED TO ACCESS YOUR BITCOINS!"
echo "***RECORD THIS NUMBER CAREFULLY*** IT CONTAINS NUMBERS 0-9 AND LETTERS A-F."
echo "THIS WILL HELP SO YOU DON'T ACCIDENTALLY CONFUSE SIMILAR LOOKING DIGITS LATER ON!"
echo "KEEP THIS HEX KEY SAFE. HIDE IT AND/OR LOCK IT UP SOMEWHERE."
echo "IT IS THE ONLY WAY TO ACCESS THE BTC IN THE FUTURE. WHOEVER HAS THAT HEX KEY"
echo "CAN SPEND YOUR MONEY. RECORD THE WHOLE LINE AFTER 'read EC key' "
echo " "
echo "ONLY USE THIS HEX KEY AND ADDRESS IF THIS SCRIPT WAS RUN OFF OF A LIVE CD WITH"
echo "NO INTERNET CONNECTION. REBOOT COMPUTER WHEN DONE TO CLEAR RAM."
echo "DO NOT COPY THIS HEX KEY ANYWHERE ONTO A COMPUTER."
echo " "



openssl ec -text -noout -in data.pem | head -5 | tail -3 | fmt -120 | sed 's/[: ]//g'
privateKeyToWIF

sleep 2

echo " "
echo "THE FOLLOWING IS THE BITCOIN ADDRESS YOU CAN SEND YOUR SAVINGS TO."
echo "RECORD THE ADDRESS CAREFULLY. IT IS NOT CRITICAL YOU KEEP THIS ADDRESS"
echo "SECRET. THE HEX CODE AND THE WALLET-IMPORT-KEYCODE MUST REMAIN SECRET!"
echo "THE LINE THAT BEGINS WITH THE NUMBER 1 IS THE BITCOIN ADDRESS."
echo " "

openssl ec -pubout < data.pem | publicKeyToAddress


echo " "
echo "SPECIAL THANKS TO 'grondilu' AND 'unk' WHO MADE THIS SCRIPT POSSIBLE!!"