Transient file sharing bash client based on GPG and redis.

LICENSE

MIT License

Copyright (c) 2017 Corin Lawson

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

pigeonhole

#!/bin/bash -ue

function -init {
    : ${GPG_BIN:=$(which gpg)}
    : ${ENCRYPT_ARGS:= -qasr $(resolve-id)}
    : ${DECRYPT_ARGS:= -q}
    : ${TEMPFILE:=/dev/null}

    exec {DB}<> /dev/tcp/"${PIGEONHOLE_HOST:=172.17.0.2}"/"${PIGEONHOLE_PORT:=6379}"
    exec {TTY}>&1
    trap '( -destroy )' EXIT
}

function -destroy {
    exec {DB}>&-
    exec {DB}<&-
    exec {TTY}>&-
}

function get {
    redis-get LPOP "$(resolve-id "$*")" | decrypt
}

function put {
    local rcpt
    local duplex=$(tempfile)
    trap "rm '$duplex'" EXIT
    cat > "$duplex"
    resolve-id "$@" | while read rcpt; do
	cat "$duplex" | encrypt "$rcpt" | redis-put LPUSH "$rcpt"
    done
}

function length {
    redis-length "$(resolve-id "$*")"
}

function redis-get {
    printf "%s \"%s\"\r\n" $1 $2 >&$DB
    read -u $DB count
    [[ "${count:1:-1}" -le 0 ]] && return
    dd bs=1 count=${count:1:-1} status=none <&$DB
    read <&$DB
}

function redis-put {
    local line
    printf "%s \"%s\" \"" $1 $2
    while read line; do
	printf '%s\\n' "${line//\"/\\\"}"
    done
    printf "\"\r\n"
    read -u $DB
    echo ${REPLY#:} >&$TTY
} >&$DB

function redis-length {
    printf "LLEN \"%s\"\r\n" $1 >&$DB
    read -u $DB count
    echo ${count:1:-1}
}

function resolve-id {
    if [[ ${#@} -gt 0 && ! -z "$1" ]]; then
	for rcpt in "$@"; do
	    "${GPG_BIN}" --with-colons --list-public-keys "$rcpt" | read-first-id pub
	done
    else
	"${GPG_BIN}" --with-colons --list-secret-keys | read-first-id sec
    fi
}

function read-first-id {
    local line
    while read line; do
	case "$line" in
	    $1:*)
		local -a fields=(${line//:/ })
		if [[ ! -z "${fields[4]}" ]]; then
		    echo ${fields[4]}
		    return
		fi
		;;
	esac
    done
}

function decrypt {
    tee "$TEMPFILE" | "${GPG_BIN}"${DECRYPT_ARGS} --decrypt -
}

function encrypt {
    "${GPG_BIN}"${ENCRYPT_ARGS} -r $1 --encrypt - | tee "$TEMPFILE"
}

function inspect {
    set -o
    type "$@"
}

function verbose {
    [[ "$TEMPFILE" == "/dev/null" ]] && TEMPFILE=$(tempfile -p pigeon)
    set -o xtrace
    -main "$@"
}

function -main {
    [[ "$(type -t $1)" =~ function ]] && "$@"
}

-init
-main "$@"