src/share/m/gen_subkey



# -*-shell-script-*-
# This should be sourced by bash (though we welcome changes to make it POSIX sh compliant)

# Monkeysphere gen-subkey subcommand
#
# The monkeysphere scripts are written by:
# Jameson Rollins <jrollins@finestructure.net>
# Jamie McClelland <jm@mayfirst.org>
# Daniel Kahn Gillmor <dkg@fifthhorseman.net>
#
# They are Copyright 2008-2009, and are all released under the GPL,
# version 3 or later.

# generate a subkey with the 'a' usage flags set

gen_subkey(){
    local keyLength
    local gpgSecOut
    local keyID
    local editCommands
    local fifoDir
    local keyType

    # get options
    while true ; do
    case "$1" in
        -l|--length)
        keyLength="$2"
        shift 2
        ;;
        *)
        if [ "$(echo "$1" | cut -c 1)" = '-' ] ; then
            failure "Unknown option '$1'.
Type '$PGRM help' for usage."
        fi
        break
        ;;
    esac
    done

    # check that the keyID is unique
    keyID=$(check_gpg_sec_key_id "$@")

    # check that an authentication subkey does not already exist
    check_gpg_authentication_subkey "$keyID"

    # determine which keyType to use from gpg version
    keyType=7
    case $(gpg --version | head -1 | awk '{ print $3 }' | cut -d. -f1) in
    1)
        if is_gpg_version_greater_equal 1.4.10 ; then
        keyType=8
        fi
        ;;
    2)
        if is_gpg_version_greater_equal 2.0.13 ; then
        keyType=8
        fi
        ;;
    *)
        keyType=8
        ;;
    esac

    # generate the list of commands that will be passed to edit-key
    editCommands="addkey
$keyType
S
E
A
Q
$keyLength
0
save"

    # setup the temp fifo dir for retrieving the key password
    log debug "creating password fifo..."
    fifoDir=$(msmktempdir)
    (umask 077 && mkfifo "$fifoDir/pass")

    # FIXME: are we adequately cleaning up any trailing gpg process here?
    trap "rm -rf $fifoDir; kill %% || true" EXIT
    echo "$editCommands" | gpg_user --passphrase-fd 3 3< "$fifoDir/pass" --expert --command-fd 0 --edit-key "$keyID" &

    log debug "Prompting for passphrase"
    # FIXME: this needs to fail more gracefully if the passphrase is incorrect
    passphrase_prompt  "Please enter your passphrase for $keyID: " "$fifoDir/pass"
    log info "Generating subkey.  This may take a long time..."

    trap - EXIT
    rm -rf "$fifoDir"
    wait
    log verbose "done."
}