#!/bin/sh
#
# uccpass, a wrapper around the pass(1) password manager for UCC
#
# David Adam <zanchey@ucc.gu.uwa.edu.au>, 2015
# (and your name here?)
#
# 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.

init () {
    # Check for pass subcommand
    if ! type pass >/dev/null; then
        echo "uccpass: can't find the pass(1) command, is it installed correctly?"
    fi
    if ! type gpg2 >/dev/null; then
        echo "uccpass: can't find gpg2(1), is it installed correctly?"
    fi

    UCCPASS_ROOT="/home/wheel/bin/uccpass"
    UCCPASS_KEYRING="$UCCPASS_ROOT/keyring.gpg"
    export PASSWORD_STORE_DIR="$UCCPASS_ROOT/store"
    export PASSWORD_STORE_UMASK=007

    export GIT_AUTHOR_EMAIL="$USER+wheel@ucc.gu.uwa.edu.au"
    export GIT_AUTHOR_NAME="`getent passwd $USER | cut -d: -f5`"

    export GPG_TTY=`tty`

    if [ -n "$UCCPASS_DEBUG" ]; then set -x; fi
}

add_to_shell () {
    # If you add more shells here, don't forget to add them to the egrep below.
    # 
    # Use keychain. It is just better than futzing around with {ssh,gpg}-agent.
    # Maybe when systemd is on everything then https://github.com/vodik/envoy
    # will be better; until then, stick with what works.
    case $USER_SHELL in
        bash)
            bash_profile=". $UCCPASS_ROOT/bash_profile.uccpass"
            grep -qsF "$bash_profile" ~/.bash_profile || echo "$bash_profile" >> ~/.bash_profile
            bashrc=". $UCCPASS_ROOT/bashrc.uccpass"
            grep -qsF "$bashrc" ~/.bashrc || echo "$bashrc" >> ~/.bashrc
            ;;
        zsh)
            zprofile=". $UCCPASS_ROOT/zprofile.uccpass"
            grep -qsF "$zprofile" ~/.zprofile || echo "$zprofile" >> ~/.zprofile
            zshenv=". $UCCPASS_ROOT/zshenv.uccpass"
            grep -qsF "$zshenv" ~/.zshenv || echo "$zshenv" >> ~/.zshenv
            ;;
        fish)
            fishconfig="source $UCCPASS_ROOT/config.uccpass.fish"
            grep -qsF "$fishconfig" ~/.config/fish/config.fish || { mkdir -p ~/.config/fish; echo $fishconfig >> ~/.config/fish/config.fish ; }
            ;;
    esac
}

refresh_keys () {
    gpg2 --quiet --import $UCCPASS_KEYRING
}

new_user_setup () {
    echo " >  Setting you up for uccpass"

    # Set up an agent
    echo -n " >> Checking for running GPG agent... "
    # Checking for a running agent sucks!
    if [ -z "$GPG_AGENT_INFO" ] || ! gpg-connect-agent /bye 2>/dev/null; then
        echo "not found."
        USER_SHELL=`basename $SHELL`
        if echo $USER_SHELL | egrep -q 'zsh|bash|fish'; then
            echo " [!] uccpass can install an password caching agent into your shell initialisation files."
            echo -n " [?] Do you want to do so? [Y/n] " 
            read install_agent
            case $install_agent in
                N|n|[Nn][Oo])
                    ;;
                *)
                    add_to_shell
                    echo " [!] You will need to start a new shell to pick up your new agent."
                    ;;
            esac
        fi
        echo -n " >> Starting GPG agent... "
        eval `SHELL=/bin/sh keychain --eval --quiet --agents gpg`
    fi
    echo "ok."

    # Generate new GPG key
    if ! gpg --list-keys $GIT_AUTHOR_EMAIL >/dev/null 2>&1; then
        echo " >> Generating new GPG key for $GIT_AUTHOR_NAME (UCC Wheel Group)"
        echo " [!] At the next prompt, you will be asked for a secure passphrase."
        echo "     This controls access to the password store - please choose something secure."
        echo " [?] Press ENTER to continue..."
        read -r _
        new_key_info="    Key-Type: default
                Subkey-Type: default
                Name-Real: $GIT_AUTHOR_NAME (UCC Wheel Group)
                Name-Email: $GIT_AUTHOR_EMAIL
                Expire-Date: 5y
                %ask-passphrase
                 "
        echo "$new_key_info" | gpg2 --gen-key --batch
    fi

    # Get the key fingerprint
    KEY_FINGERPRINT=`gpg --list-secret-keys --with-fingerprint --with-colons $GIT_AUTHOR_EMAIL | grep '^fpr' | head -n 1 | cut -d: -f 10`

    # Add to .gpg-id
    echo -n " >> Adding your key to the access list... "
    if grep -qF "$KEY_FINGERPRINT" $PASSWORD_STORE_DIR/.gpg-id; then
        echo "already present!"
    else
        echo "$KEY_FINGERPRINT" >> $PASSWORD_STORE_DIR/.gpg-id
        echo "ok."
    fi

    # Add to key list
    # XXX: is it worth submitting these to an online keyserver?
    echo -n " >> Adding your key to the shared keyring... "
    if gpg2 --with-fingerprint --with-colons $UCCPASS_KEYRING | grep -qF "$KEY_FINGERPRINT"; then
        echo "already present!"
    else
        gpg2 --export --armor "$KEY_FINGERPRINT" >> $UCCPASS_KEYRING && echo "ok."
    fi

    # Done!
    echo " > uccpass setup complete."
    echo " [!] Ask someone with existing access to the password store to run \`uccpass reload\`."
}

init

case "$1" in
    setup)
        new_user_setup
        refresh_keys
        ;;
    reload)
        refresh_keys
        echo "The following keys have access to the password store:"
        gpg2 --with-colons --list-keys `cat $PASSWORD_STORE_DIR/.gpg-id` | grep '^uid' | cut -d: -f 10
        echo
        command pass init `cat $PASSWORD_STORE_DIR/.gpg-id`
        ;;
    help|--help)
        command pass $@
        echo "uccpass also supports the following commands:"
        echo "setup: generate a new key and insert it into the password store"
        echo "reload: re-encrypt the password store"
        ;;
    insert|edit|generate|rm|cp|mv|git)
        refresh_keys
        command pass $@
        ;;
    *)
        command pass $@
        ;;
esac

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