A selection of commands to encode, decode and convert

en-de-code.sh

#!/bin/bash

## Use PHP to Encode and Decode Hex, Binary, Base64 and Json - you can also cat the info from a file to most of these commands
# i.e cat file-with-data.txt | php -r "echo implode(unpack('H*', file_get_contents('php://stdin')));"

# Encode string to hex
echo -n "reptilehaus" | php -r "echo implode(unpack('H*', file_get_contents('php://stdin')));"
echo -n "reptilehaus" | php -r "echo bin2hex(file_get_contents('php://stdin'));"

# Decode hex to string 
echo -n "72657074696c6568617573" | php -r "echo pack('H*', file_get_contents('php://stdin'));"
echo -n "72657074696c6568617573" | php -r "echo hex2bin(file_get_contents('php://stdin'));"

# base64 encode string
echo -n "reptilehaus"| php -r "echo base64_encode(file_get_contents('php://stdin'));"

# base64 decode string 
echo -n "cmVwdGlsZWhhdXM=" | php -r "echo base64_decode(file_get_contents('php://stdin'));"

# json decode
echo -n '{"jsonrpc":"2.0","method":"net_peerCount","params":[],"id":74}' | php -r "var_dump(json_decode(file_get_contents('php://stdin')));"
echo -n '{"jsonrpc":"2.0","method":"net_peerCount","params":[],"id":74}' | php -r "print_r(json_decode(file_get_contents('php://stdin')));"

# JSON encode
php -r "echo json_encode( array('a' => 1, 'b' => 2, 'c' => 3, 'd' => 4, 'e' => 5) );"

# JSON encode then chain the output to json_decode via STDIN
php -r "echo json_encode( array('a' => 1, 'b' => 2, 'c' => 3, 'd' => 4, 'e' => 5) );"  | php -r "var_dump(json_decode(file_get_contents('php://stdin')));"

# A string has been double encoded; first with hex, then base64; We decode base64 first then decode the hex to get the string (found in bug bounty)
echo -n 'NmQyNDI0NzE2YzVmNTM0MDVmNTA0MDczNzM1NzMwNzI2NDIx' | base64 -D | php -r "echo hex2bin(file_get_contents('php://stdin'));"

# Decode a hexadecimal to integer
echo -n '0x7e3' | php -r "echo hexdec(file_get_contents('php://stdin'));"

# Encode an integer to hexadecimal
echo -n '2019' | php -r "echo '0x'.dechex(file_get_contents('php://stdin'));"

# Decode hex to string
echo "0: 72657074696c6568617573" | xxd -r



## Get Hash of a file (if OS doesnt have native functions but does have openssl i.e OSX)

# Get a files SHA256 hash
openssl sha256 ~/Desktop/contract.pdf  | awk '{print $2}';

# Get a files SHA1 hash
openssl sha1 ~/Desktop/contract.pdf  | awk '{print $2}';

# Get a files MD5 hash
openssl md5 ~/Desktop/contract.pdf | awk '{print $2}';

# Generate a local SSL Certificate
openssl req -newkey rsa:2048 -new -nodes -x509 -days 3650 -keyout ~/Desktop/key.pem -out  ~/Desktop/cert.pem

# Check the expiry date of an SSL Certificate
openssl s_client -connect example.com:443 2>/dev/null </dev/null | openssl x509 -noout -enddate



## Not necessarily usefull for Bug Bounty but good for Developers converting videos between formats on the fly

# first install ffmpeg
# brew install ffmpeg --with-fdk-aac --with-ffplay --with-freetype --with-frei0r --with-libass --with-libvo-aacenc --with-libvorbis --with-libvpx --with-opencore-amr --with-openjpeg --with- --with-rtmpdump --with-schroedinger --with-s+

# Convert an MP4 video to Og vorbis
ffmpeg -i input.mp4 -q:v 10 -c:v libtheora -c:a libvorbis output.ogv

# Convert MP4 to WebM
ffmpeg -i input.mp4 -q:v 10 -c:v libvpx -c:a libvorbis output.webm