cipfs.sh

#!/bin/bash

echo
echo \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*
echo "    Confidential IPFS, v0.1"
echo @isthmus \(github.com\/mitchellpkt\)
echo \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*
echo
echo --------
echo NOTICES:
echo -  CIPFS requires standard PGP and IPFS to be installed
echo -  This implementation provides OFF-DEVICE security
echo -  Feel free to improve, modify, and distribute CIPFS code \& protocol
echo \ \ \(please include attribution and PR useful tweaks to origin repo\)
echo -  Default behavior is deterministic key generation
echo \ \ \i.e. symmetric encrypt with first 32 chars of SHA-256 sum, so that:
echo \ \ identical files ==\> identical ciphertexts ==\> no IPFS bloat
echo   -  If your threat model is sensitive to IPFS storage hypothesis testing, 
echo   \ \ "then add --random-key flag to generate a unique one-time key"
echo 
echo --------
echo PROGRESS:
echo

############
############
## CIPFS GET
############
############

if [ "$1" == "add" ]; then

####################
## What type of key?

# If --random-key, then generate random 32-char alphanumeric key
if [[ " $* " == *' --random-key '* ]]; then
KEY=$(cat /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w 32 | head -n 1)
echo ... generated random key

# If not `--random-key` then use first 32 chars of sha256sum as key
else
FHASH=$(sha256sum $2)
KEY=$(echo "$FHASH" | cut -b 1-32)
echo ... generated deterministic key
fi


####################
## Encrypt the file
gpg --yes --batch --passphrase=$KEY --cipher-algo AES256 -c $2
echo ... encrypted $2
	
####################
## Upload to IPFS
echo ... uploading to IPFS
echo
IPFS_OUTPUT=`ipfs add $2.gpg`
echo
rm $2.gpg

####################
## Extract IPFS key
IPFS_HASH=$(echo $IPFS_OUTPUT | awk '{print $2}')
echo
echo \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*
echo Retrieve file with this CIPFS ticket:
echo C$IPFS_HASH$KEY
echo \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*
echo

fi

############
############
## CIPFS GET
############
############

if [ "$1" == "get" ]; then

####################
## Extract the address & key
x=$2
FNAME=$(echo "$x" | cut -b 2-47)
KEY=$(echo "$x" | cut -b 48-$((48+32)))

####################
## Download from IPFS
IPFS_OUTPUT=`ipfs get $FNAME`
echo
echo ... downloaded from IPFS
mv $FNAME $FNAME.gpg

####################
## Decrypt the file
gpg --yes --batch --quiet --cipher-algo AES256 --passphrase=$KEY $FNAME.gpg
rm $FNAME.gpg
mv $FNAME C$FNAME
echo ... decrypted file

####################
## Display file info
echo
echo \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*
echo Retrieved file name:
echo C$FNAME
echo
echo Retrieved file SHA-256 sum:
VARI=$(sha256sum C$FNAME)
echo $VARI | head -n1 | awk '{print $1;}'
echo \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*
echo

fi