myshellconfig/bin/startagent

#!/bin/bash

FILELOGLEVEL=DEBUG
DEFAULT_SOCKET_REMOTE=~/.ssh/ssh_from_remote_auth_sock
. $(dirname $0)/../logging
# loggerfactory
LANG=C

usage(){
    cat << EOF

    Usage: $(basename $0) [[-c]|[--create-only]]|[[-t]|[--token-only]]|[[-k]|[--key-only]]|[[-r]|[-f]|[--readd]|[--force]] [<ssh-identity>]

    If started only with <ssh-identity>, the script looks up in configured identity-path \$SSH_IDENTITIES_DIR (${SSH_IDENTITIES_DIR}) if it can find a directory named after <ssh-identity>.
    If no <ssh_identity> is given, the identity is set to \$SSH_DEFAULT_IDENTITY ($SSH_DEFAULT_IDENTITY) configured via Environment.
    IF \$SSH_DEFAULT_IDENTITY is also not set, default is the SSH_DEFAULT_IDENTITY

    The output is the name of the file, where ssh-agent infomations are hold to load it to current shell for further actions.
    Use "$ eval \$(<outputfilenam>)", if you want to load the SSH_AUTH_SOCK and SSH_AGENT_PID in current shell or shorter "$ loadagent [<ssh_identity>]"

    -c|--create-only                Create or restart only the agent. Do not load any 
                                    key or token in it.
                                    The Output is used for loading the agent in the current
                                    shell. (loadagent <identity>)
    -t|--token-only                 To add or renew only configured pkcs11-hardware-token
                                    configured in ${SSH_IDENTITIES_DIR}/<ssh-identity>,
                                    just use this. 
    -k|--key-only                   To add or renew only configured keys configured in
                                    ${SSH_IDENTITIES_DIR}/<ssh-identity>, just use this.
    -r|-f|--readd-token|--force    remove all in ${SSH_IDENTITIES_DIR}/<ssh-identity> 
                                    configured keys and tokens and readd them again.
                                    Depends on -t an -k Option to select wheter only 
                                    keys or tokens only. If no -t and -k is given, all 
                                    keys and token are removed and readded again.
                                    Just to be asked for password again, if you plugged off
                                    hardware-token and plugged it in again.
    --rm|--remove                   remove keys and token instead of adding them.
    -h|--info                       Show this info


EOF
}

create_filenamebase() {
    printf "%s" "${ssh_identity}-$(hostname)"
}

create_agentfilename() {
    printf "%s" "${SSH_AGENTS_DIR}/agent-$(create_filenamebase)"
}

create_socketfilename() {
    printf "%s" "${SSH_AGENT_SOCKETS_DIR}/socket-$(create_filenamebase)"
}

ssh_runinagent() {

    local SSH_AUTH_SOCK
    local SSH_AGENT_PID
    local PKCS11_MODULE
    local agentfile
    local command
    local agentfile=${1}
    shift
    local sshcommand=${@}

    logdebug "agentfile: ${agentfile}"
    logtrace "run command »$sshcommand« in agent $agentfile" 
    if [ -e "$agentfile" ]; then 
        #/bin/sh -c "unset SSH_AUTH_SOCK SSH_AGENT_PID PKCS11_MODULE; eval $(<$agentfile) >/dev/null 2>&1; echo SSH_AUTH_SOCK ${SSH_AUTH_SOCK:-not set} >&2; $sshcommand"
        #unset SSH_AUTH_SOCK SSH_AGENT_PID PKCS11_MODULE
        . $agentfile >/dev/null
        logdebug "SSH_AUTH_SOCK: ${SSH_AUTH_SOCK:-not set}"
        logdebug "SSH_AGENT_PID: ${SSH_AGENT_PID:-not set}"
        logdebug "PKCS11_MODULE: ${PKCS11_MODULE:-not set}"
        $sshcommand
        ret=$?
    else
        logwarning "agentfile not existent" 
        ret=99
    fi

    return $ret

}

set_and_load_identity_config() {

    # check if idendity directory an file config exists in it.
    # if it exist, source it
    #ssh_identity="${1}"
    ssh_identity_dir="${SSH_IDENTITIES_DIR}/${ssh_identity}"
    loginfo "ssh-identity: ${ssh_identity}"
    loginfo "ssh-identity_dir: ${ssh_identity_dir}"
    if [ -d ${ssh_identity_dir} ]; then
        loginfo "Directory identity-dir ${ssh_identity_dir} exists. Use it"
    else
        logwarning "Directory identity-dir ${ssh_identity_dir} does not exist. Use default-config"
        ssh_identity=default
        ssh_identity_dir="${SSH_IDENTITIES_DIR}/${ssh_identity}"
    fi

    if [ -e "${ssh_identity_dir}/config" ]; then
        logdebug "source ${ssh_identity_dir}/config"
        unset SSH_AUTH_SOCK SSH_AGENT_PID PKCS11_MODULE SSH_AGENT_ALLOW_FROM_REMOTE SSH_ADD_OPTION
        . "${ssh_identity_dir}/config"
    fi

}

start_or_restart_local_agent() {
    if [ -e "${ssh_agentfile}" ]
    then
        logdebug "agentfile ${ssh_agentfile} exists"
        eval $(<$ssh_agentfile) >/dev/null 2>&1
        logdebug "SSH_AUTH_SOCK: ${SSH_AUTH_SOCK:-not set}"
        logdebug "SSH_AGENT_PID: ${SSH_AGENT_PID:-not set}"
        logdebug "PKCS11_MODULE: ${PKCS11_MODULE:-not set}"
        for i in $(pgrep -f ${SSH_AUTH_SOCK})
        do
            logdebug "$(stat ${SSH_AUTH_SOCK})"
            logdebug "found pid: $i"
            logdebug "is SSH_AGENT_PID set?" [ -n "${SSH_AGENT_PID:+x}" ]
            logdebug "is $SSH_AGENT_PID same as found pid $i:" [ $i -eq ${SSH_AGENT_PID} ]
            ${REMOTE_UNUSED_AGENTS:-false} && { [ -n "${SSH_AGENT_PID:+x}" ] && [ $i -eq ${SSH_AGENT_PID} ] || { logwarning "kill unused ssh-agent with pid $i"; kill $i; }; }
        done
        if [ -e ${ssh_socketfile} ]
        then
            case $(pgrep -f ${SSH_AUTH_SOCK}|wc -l) in
                0)
                    logdebug "no ssh-agents for file ${ssh_socketfile}"
                    ret=3
                    ;;
                1)
                    logdebug "one running agent for file ${ssh_socketfile}. Use it"
                    msg="$(ssh_runinagent $ssh_agentfile "ssh-add -v -l 2>&1")"
                    ret=$?
                    logdebug "SSH_AUTH_SOCK: $SSH_AUTH_SOCK"
                    ;;
                *)
                    logdebug "more than one ssh-agents for file ${ssh_socketfile}"
                    return 3
                    ;;
            esac
        else
            logdebug "remove socketfile: $( rm -v -f "$ssh_socketfile" )"
            msg="$(ssh_runinagent $ssh_agentfile "ssh-add -v -l 2>&1")"
            ret=$?
        fi
        logdebug "ret: $ret"
        #msg="$(ssh-add -l 2>&1)"
        logtrace "Output from check for running agent: $msg"
        case $ret in
            0)
                logdebug "agent is running" 
                ;;
            1)
                logdebug "agent is running, but:" 
                logwarning "$msg"
                ;;
            2|3|99)
                logdebug "former agent is not running -> start it" 
                logdebug "remove socketfile: $( rm -v -f "$ssh_socketfile" )"
                logdebug "remove agentfile: $( rm -v -f "$ssh_agentfile" )"
                #logdebug "$(ssh-agent -k)"
                logdebug "SSH_AGENT_OPTIONS: $SSH_AGENT_OPTIONS"
                logtrace "$(ssh-agent -a $ssh_socketfile ${SSH_AGENT_OPTIONS} > $ssh_agentfile )"
                logdebug "PKCS11_MODULE: ${PKCS11_MODULE:-not set}"
                sed '/^PKCS11_MODULE/d' ${ssh_agentfile}
                [ -n "${PKCS11_MODULE:+x}" ] && logdebug "add PKCS11_MODULE to ${ssh_agentfile}"
                [ -n "${PKCS11_MODULE:+x}" ] && echo "PKCS11_MODULE=$PKCS11_MODULE; export PKCS11_MODULE" >> ${ssh_agentfile}
                logdebug "agent started" 
                ;;
            4)
                logdebug "this is strange"
                ;;
        esac
    else
        logdebug "ssh_agentfile ${ssh_agentfile} does not exist"
        logdebug "remove socketfile: $( rm -v -f "$ssh_socketfile" )"
        logdebug "remove agentfile: $( rm -v -f "$ssh_agentfile" )"
        logdebug "SSH_AGENT_OPTIONS: $SSH_AGENT_OPTIONS"
        logtrace "$(ssh-agent -a $ssh_socketfile ${SSH_AGENT_OPTIONS} > $ssh_agentfile )"
        logdebug "PKCS11_MODULE: ${PKCS11_MODULE:-not set}"
        sed '/^PKCS11_MODULE/d' ${ssh_agentfile}
        [ -n "${PKCS11_MODULE:+x}" ] && logdebug "add PKCS11_MODULE to ${ssh_agentfile}"
        [ -n "${PKCS11_MODULE:+x}" ] && echo "PKCS11_MODULE=$PKCS11_MODULE; export PKCS11_MODULE" >> ${ssh_agentfile}
        logdebug "agent started" 
    fi

}


check_and_link_socket() {

    if ${SSH_AGENT_ALLOW_FROM_REMOTE:-false}
    then
        logdebug "Remote agent allowed."
        if [ -e ${DEFAULT_SOCKET_REMOTE} ] 
        then
            logdebug "Link remote socket to ${ssh_socketfile}"
            ln -f -s $(readlink -f ${DEFAULT_SOCKET_REMOTE}) ${ssh_socketfile}
            [ -e ~/.ssh/p11m ] && . ~/.ssh/p11m
            logdebug "Write new agentfile ${ssh_agentfile}"
            cat << EOF > ${ssh_agentfile}
SSH_AUTH_SOCK=$ssh_socketfile; export SSH_AUTH_SOCK;
${P11M:+PKCS11_MODULE=${P11M}; export PKCS11_MODULE}
EOF
        else
            logdebug "Use local agent"
            start_or_restart_local_agent
        fi
    else
        logdebug "Only local agent allowed"
        loginfo "SSH_AUTH_SOCK=${SSH_AUTH_SOCK} and ssh_agentfile=${ssh_agentfile}"
        if [ -e ${ssh_agentfile} -a $(grep SSH_AUTH_SOCK ${ssh_agentfile} >/dev/null; echo $?) -eq 0 ]
        then
            logdebug "agentfile exists"
        else
            logdebug "agentfile is missing -> kill all ssh-agents for socket"
            pkill -f ${ssh_socketfile}
        fi
        if [ -L ${ssh_socketfile} ]
        then
            logdebug "${ssh_socketfile} is symlinked to $(readlink -f ${ssh_socketfile}). Remove it"
            rm ${ssh_socketfile}
        else
            if [ -e ${ssh_socketfile} -a $(pgrep -f ${ssh_socketfile} >/dev/null 2>&2; echo $?) ]
            then
                logdebug "Socket and agent for ${ssh_socketfile} are up and a running agent exist. Use it"
            else
                logdebug "No agent for socket ${ssh_socketfile} or socket does not exist, remove both if possible"
                rm -f ${ssh_socketfile}
                pkill -f ${ssh_socketfile}
            fi

        fi
        start_or_restart_local_agent
    fi

}

check_pubkeys_and_certs() {

    for pubkey in $(ls ${SSH_IDENTITIES_DIR}/${ssh_identity}/id_*|grep "pub$\|public$"|grep -v "cert.pub"); do
        if $( ls ${pubkey%.pub} 1>/dev/null 2>&1);then
            logdebug "pubkey with privkey: ${pubkey} | ${pubkey%.pub}"
        else
            logdebug "pubkey without privkey: $pubkey"
            pubkeysonly+=($pubkey)
        fi
        if [ -e "${pubkey%.pub}-cert.pub" ]; then
            cert_exp_date=$(ssh-keygen -L -f "${pubkey%.pub}-cert.pub"|awk '$1 == "Valid:"{print $5}')
            [ $(date +%s -d $cert_exp_date) -gt $(date +%s -d NOW) ] \
            || logwarning "CERTIFICATE IS NOT VALID ANYMORE: ${pubkey%.pub}-cert.pub"
            [ $(date +%s -d $cert_exp_date) -lt $(date +%s -d "$SSH_CERT_VALIDITY_WARN_SEC") ] \
                && logwarning "CERTIFICATE expires in $(echo "scale=0; ( `date -d $cert_exp_date +%s` - `date -d now +%s`) / (24*3600)" | bc -l) days: ${pubkey%.pub}-cert.pub"
        fi
        logwarning "$(ssh-add -T ${pubkey})"
    done


}

load_or_reload_identities() {
    # If DISPLAY is set, ssh-add calls ssh-askpass, and if its in remote-terminal, it wont work
    # So remember and unset DISPLAY, and set it at the end again, if it was set before
    [ $DISPLAY ] && local DISPLAY_ORIG=$DISPLAY
    [ $DISPLAY ] && logtrace "unset DISPLAY: $DISPLAY"
    [ $DISPLAY ] && unset DISPLAY

    logdebug "  ssh_idendity=${ssh_identity}"
    logdebug "Now load all identities for ${ssh_identity} from ${ssh_identity_dir}"
    logdebug "PKCS11_MODULE: ${PKCS11_MODULE:-not set}"
    local fingerprint
    declare -a fingerprints
    local pubkeysonly
    declare -a pubkeysonly
    fingerprints=( $(ssh-add -l|awk '{print $2}') )
    logdebug "fingerprints from loaded keys before action:"
    for f in ${fingerprints[@]};do
        logdebug "$f"
    done
    for key in $(ls ${SSH_IDENTITIES_DIR}/${ssh_identity}/id_*|grep -v "pub$\|so$\|config$\|public$"); do
        fingerprint=$(ssh-keygen -l -f $key|awk '{print $2}')
        if [[ ${fingerprints[*]} =~ "$fingerprint" ]]; then
            logdebug "key: $(basename $key) (with fp $fingerprint) is loaded" 
        else
            logdebug "key: $key is not loaded -> load it" 
            logdebug "$(ssh-add ${SSH_ADD_OPTIONS} ${key} 2>&1)"
        fi
    done
    for pubkey in $(ls ${SSH_IDENTITIES_DIR}/${ssh_identity}/id_*|grep "pub$\|public$"|grep -v "cert.pub"); do
        if $( ls ${pubkey%.pub} 1>/dev/null 2>&1);then
            logdebug "pubkey with privkey: ${pubkey} | ${pubkey%.pub}"
            logdebug "$(ssh-add -T ${pubkey} || ssh-add ${pubkey})"
        else
            logdebug "pubkey without privkey: $pubkey"
            pubkeysonly+=($pubkey)
        fi
        if [ -e "${pubkey%.pub}-cert.pub" ]; then
            cert_exp_date=$(ssh-keygen -L -f "${pubkey%.pub}-cert.pub"|awk '$1 == "Valid:"{print $5}')
            [ $(date +%s -d $cert_exp_date) -gt $(date +%s -d NOW) ] \
            || logwarning "CERTIFICATE IS NOT VALID ANYMORE: ${pubkey%.pub}-cert.pub"
            [ $(date +%s -d $cert_exp_date) -lt $(date +%s -d "$SSH_CERT_VALIDITY_WARN_SEC") ] \
                && logwarning "CERTIFICATE expires in $(echo "scale=0; ( `date -d $cert_exp_date +%s` - `date -d now +%s`) / (24*3600)" | bc -l) days: ${pubkey%.pub}-cert.pub"
        fi
    done
    for pubkey in ${pubkeysonly[@]}
    do
        logdebug "Pubkey: ${pubkey}"
        logdebug " SSH_AUTH_SOCK=${SSH_AUTH_SOCK}"
        ssh-add -T ${pubkey} >/dev/null
        if [ $? -gt 0 ]
        then
            logdebug "Pubkey ${pubkey} is not usable"
            if [ -n "${PKCS11_MODULE:+x}" ]
            then
                logdebug "PKCS11_MODULE is set ${PKCS11_MODULE:-not set}"
                logdebug "$(ssh-add -e $PKCS11_MODULE)" && logdebug "$(ssh-add -s $PKCS11_MODULE)"
            else
                logdebug "No PKCS11_MODULE defined"
            fi
        else
            logdebug "Pubkey ${pubkey} is usable"
            if [ -n "${PKCS11_MODULE:+x}" ]
            then
                logdebug "PKCS11_MODULE is set ${PKCS11_MODULE:-not set}"
            else
                logdebug "No PKCS11_MODULE defined"
            fi
        fi
    done


    [ $DISPLAY_ORIG ] && logtrace "reset DISPLAY=$DISPLAY_ORIG"
    [ $DISPLAY_ORIG ] && export DISPLAY=$DISPLAY_ORIG

}

##################################################
SCRIPTENTRY

createonly=false
tokenonly=false
readd=false
keyonly=false
remove=false
while :; do
    case $1 in
        -c|--create-only)
            createonly=true
            shift
            ;;
        -h|--info)
            usage
            exit 0
            ;;
        -*)
            echo "Unknown urgument: »$1«" >&2
            exit 1
            ;;
        *)
            #ssh_identity=${1-${SSH_DEFAULT_IDENTITY}}
            ssh_identity=${1}
            break
            ;;
    esac
done
[ -z "${SSH_IDENTITIES_DIR+x}" ]    && { SSH_IDENTITIES_DIR="${SSH_IDENTITIES_DEFAULT_DIR-${HOME}/.ssh/identities}"; export SSH_IDENTITIES_DIR; }
[ -z "${SSH_AGENTS_DIR+x}" ]        && { SSH_AGENTS_DIR=${SSH_AGENTS_DEFAULT_DIR-~/.ssh/agents}; export SSH_AGENTS_DIR; }
[ -z "${SSH_AGENT_SOCKETS_DIR+x}" ] && { SSH_AGENT_SOCKETS_DIR=${SSH_AGENT_SOCKETS_DEFAULT_DIR-~/.ssh/agents}; export SSH_AGENT_SOCKETS_DIR; }
[ -z "${SSH_AGENT_OPTIONS+x}" ]     && { SSH_AGENT_OPTIONS=${SSH_AGENT_DEFAULT_OPTIONS--t 7200 }; export SSH_AGENT_OPTIONS; }
logtrace "       SSH_AGENTS_DIR: $SSH_AGENTS_DIR"
logtrace "SSH_AGENT_SOCKETS_DIR: $SSH_AGENT_SOCKETS_DIR"
logtrace "   SSH_IDENTITIES_DIR: $SSH_IDENTITIES_DIR"
[ -z "${SSH_AGENTS_DIR-x}" ]        || mkdir -vp "$SSH_AGENTS_DIR"
[ -z "${SSH_AGENT_SOCKETS_DIR-x}" ] || mkdir -vp "$SSH_AGENT_SOCKETS_DIR"
[ -z "${SSH_IDENTITIES_DIR-x}" ]    || mkdir -vp "$SSH_IDENTITIES_DIR"
logdebug "ssh_idendity: ${ssh_identity}"

unset SSH_AUTH_SOCK SSH_AGENT_PID PKCS11_MODULE SSH_AGENT_ALLOW_FROM_REMOTE

ssh_agentfile=$(create_agentfilename)
ssh_socketfile=$(create_socketfilename)

set_and_load_identity_config ${ssh_identity}
sed -i -e '/PKCS11_MODULE/d' ${ssh_agentfile}
if [ -n ${PKCS11_MODULE:+x} ]
then
    echo "PKCS11_MODULE=${PKCS11_MODULE}; export PKCS11_MODULE" >> ${ssh_agentfile}
fi
[ -e $ssh_agentfile ] && eval $(<${ssh_agentfile}) >/dev/null
logdebug "              PKCS11_MODULE=${PKCS11_MODULE:-not set}"

logdebug "            SSH_ADD_OPTIONS=${SSH_ADD_OPTIONS:-not set}"
logdebug "SSH_AGENT_ALLOW_FROM_REMOTE=${SSH_AGENT_ALLOW_FROM_REMOTE:-false}"
logdebug "              PKCS11_MODULE=${PKCS11_MODULE:-not set}"
logdebug "                       P11M=${P11M:-not set}"
logdebug "              SSH_AUTH_SOCK=${SSH_AUTH_SOCK:-not set}"
logdebug "       SSH_AUTH_SOCK_REMOTE=${SSH_AUTH_SOCK_REMOTE:-not set}"
logdebug "               ssh_idendity=${ssh_identity}"

check_and_link_socket
logdebug "SSH_AGENT_FILE=${ssh_agentfile}"
logdebug " SSH_AGENT_PID=${SSH_AGENT_PID}"
logdebug " SSH_AUTH_SOCK=${SSH_AUTH_SOCK}"
logdebug "  ssh_idendity=${ssh_identity}"
$createonly || load_or_reload_identities
$createonly && printf "%s" "${ssh_agentfile}"
logtrace "cat ${ssh_agentfile}
$(cat ${ssh_agentfile})"


SCRIPTEXIT
loginfo "return with $res"
exit $res