myshellconfig/bin/ssh-agent-start-or-restart

#!/bin/bash

loadonly=false
tokenonly=false
while :; do
    case $1 in
        -l|--load-only-agent)
            loadonly=true
            shift
            ;;
        -t|--token-only)
            tokenonly=true
            shift
            ;;
        *)
            ssh_identity=$1
            break
            ;;
    esac
done

SCRIPTENTRY
[ -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; }
logdebug "SSH_AGENTS_DIR: $SSH_AGENTS_DIR" >&2
logdebug "SSH_AGENT_SOCKETS_DIR: $SSH_AGENT_SOCKETS_DIR" >&2
logdebug "SSH_IDENTITIES_DIR: $SSH_IDENTITIES_DIR" >&2
[ -z "${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"

agent-start-or-restart () {
    
    ENTRY
    local ssh_identity
    local agentfile
    local agentsocket

    if [ -n "${1+x}" ]; then
        ssh_identity="$1"
        agentfile="${SSH_AGENTS_DIR}/agent-${ssh_identity}-$(hostname)"
        agentsocket="${SSH_AGENT_SOCKETS_DIR}/socket-${ssh_identity}-$(hostname)"
        logdebug "agentfile: $agentfile" >&2
        logdebug "agentsocket: $agentsocket" >&2
        logdebug "ssh-identität: $ssh_identity" >&2
        if [ -e $agentfile ]; then

            local msg="$(/bin/sh -c "unset SSH_AUTH_SOCK SSH_AGENT_PID; . $agentfile >/dev/null 2>&1; ssh-add -l")"
            local ret=$?
            logdebug "$msg"
            case $ret in
                0)
                    loginfo "agent is running" >&2
                    ;;
                1)
                    logwarn "command failed on ssh-agent"
                    ;;
                2)
                    loginfo "former agent is not running" >&2
                    [ -e $agentsocket ] && { logdebug -n "remove socketfile: $( rm -v "$agentsocket" )"; }
                    logdebug "$(ssh-agent -a $agentsocket $SSH_AGENT_OPTIONS > $agentfile )"
                    loginfo "agent started" >&2
                    ;;
            esac
        else
            loginfo "agent did not exist" >&2
            #rm "$agentsocket"
            logdebug "ssh-agent -a $agentsocket \> $agentfile"
            logdebug "$(ssh-agent -a $agentsocket $SSH_AGENT_OPTIONS > $agentfile )"
            loginfo "agent started" >&2
        fi

        logdebug "agent for $ssh_identity: $agentfile"
        echo $agentfile
        return 0

    else
        logwarn "no identity given - exit" >&2
        return 1
    fi

    EXIT

}

agent-load-identity-keys () {

    ENTRY
    local ssh_identity
    local agentfile
    local agentsocket
    local fingerprints
    declare -a fingerprints
    local fingerprint
    local tokenfingerprint

    if [ -n "${1+x}" ]; then
        ssh_identity="$1"
        identitydir=${SSH_IDENTITIES_DIR}/${ssh_identity}
        [ -e "${identitydir}/config" ] && . "${identitydir}/config"
        agentfile="${SSH_AGENTS_DIR}/agent-${ssh_identity}-$(hostname)"
        agentsocket="${SSH_AGENT_SOCKETS_DIR}/socket-${ssh_identity}-$(hostname)"
        loginfo "ssh-identität: $ssh_identity" >&2
        loginfo "SSH_ADD_OPTIONS: $SSH_ADD_OPTIONS"
        logdebug "agentfile: $agentfile" >&2
        logdebug "agentsocket: $agentsocket" >&2
        logdebug "identitydir: $identitydir"

        fingerprints=( $(ssh-runinagent $agentfile "ssh-add -l|awk '{print \$2}'") )
        if ! $tokenonly ; then
            for key in $(ls ${SSH_IDENTITIES_DIR}/${ssh_identity}/id_*|grep -v "pub$\|so$\|config$\|public$"); do
                logdebug "key: $key"
                fingerprint=$(ssh-keygen -l -f ~/.ssh/identities/bmi/id_ed25519|awk '{print $2}')
                logtrace "${fingerprints[*]} and $fingerprint"
                if [[ ${fingerprints[*]} =~ "$fingerprint" ]]; then
                    logdebug "$key is loaded" >&2
                else
                    logdebug "$key is not loaded" >&2
                    loginfo "$(ssh-runinagent $agentfile ssh-add ${SSH_ADD_OPTIONS} ${key})"
                fi
            done
        fi
        for token in $(ls ${SSH_IDENTITIES_DIR}/${ssh_identity}/*|grep  "\.so$"); do
            logdebug "token: $token"
            tokenfingerprint="$(ssh-keygen -l -D $token|tr -s ' '|awk '{print $2}')"
            logtrace "${fingerprints[*]} and $tokenfingerprint"
            if [[ ${fingerprints[*]} =~ "$tokenfingerprint" ]]; then
                logdebug "$token is loaded" >&2
            else
                logdebug "$token is not loaded" >&2
                loginfo "$(ssh-runinagent $agentfile ssh-add ${SSH_ADD_OPTIONS} -s ${token})"
            fi
        done
        logdebug "current loaded keys: $(ssh-runinagent $agentfile ssh-add -l)"
    fi
    EXIT
}

ssh-runinagent () {

    ENTRY

    local agentfile
    local command
    agentfile=${1}
    shift
    sshcommand=${@}

    logdebug "run command »$sshcommand« in agent $agentfile" >&2
    if [ -e "$agentfile" ]; then 
        /bin/sh -c "unset SSH_AUTH_SOCK SSH_AGENT_PID; . $agentfile >/dev/null 2>/dev/null; $sshcommand"
        EXIT
        return $?
    else
        logwarn "agentfile not existent" >&2
        EXIT
        return 1
    fi


}

agent-start-or-restart $ssh_identity
! $loadonly && agent-load-identity-keys $ssh_identity
SCRIPTEXIT
exit $?