From a206271460ce49e842b1b410c0424b8c9a0a3d14 Mon Sep 17 00:00:00 2001 From: Nuno Goncalves Date: Sat, 12 Jun 2021 04:03:25 +0200 Subject: [PATCH] ssh-agent: improvements (#6309) * ssh-agent: lock this script with a mkdir style mutex This script is a kind of singleton pattern and is not reentrant. If several shells are oppened in a fast sequence, then several independent ssh-agents would be created, which is not acceptable. A mutex is required. Signed-off-by: Nuno Goncalves * ssh-agent: only start agent if .ssh dir exists To use the same profile system-wide, it might happen that the .ssh directory does not exist (typically $HOME/.ssh/). This would trigger a error. Creating the directory would be a option, but it usually will not make sense to do so because it means the user doesn't have ssh keys or config. Signed-off-by: Nuno Goncalves * ssh-agent: adds lazy option to disable key loading on start Option is documented on updated README.md Signed-off-by: Nuno Goncalves * ssh-agent: simplify agent-forwarding checking Signed-off-by: Nuno Goncalves Co-authored-by: Robby Russell --- plugins/ssh-agent/README.md | 12 +++++++++-- plugins/ssh-agent/ssh-agent.plugin.zsh | 29 +++++++++++++++++++------- 2 files changed, 31 insertions(+), 10 deletions(-) diff --git a/plugins/ssh-agent/README.md b/plugins/ssh-agent/README.md index 8765a9c7e..aa96f9cc9 100644 --- a/plugins/ssh-agent/README.md +++ b/plugins/ssh-agent/README.md @@ -19,9 +19,17 @@ To enable **agent forwarding support** add the following to your zshrc file: zstyle :omz:plugins:ssh-agent agent-forwarding on ``` ----- +To **NOT load any identities on start** use the `lazy` style. +This is particularly usefull when combined with the AddKeysToAgent +(available from OpenSSH 7.2), since it allows to enter the password only +on first use. -To **load multiple identities** use the `identities` style, For example: +```zsh +zstyle :omz:plugins:ssh-agent lazy yes +``` + +To **load multiple identities** use the `identities` style. This have no +effect if `lazy` is enabled. ```zsh zstyle :omz:plugins:ssh-agent identities id_rsa id_rsa2 id_github diff --git a/plugins/ssh-agent/ssh-agent.plugin.zsh b/plugins/ssh-agent/ssh-agent.plugin.zsh index d45406f63..494cf1393 100644 --- a/plugins/ssh-agent/ssh-agent.plugin.zsh +++ b/plugins/ssh-agent/ssh-agent.plugin.zsh @@ -1,4 +1,16 @@ -typeset _agent_forwarding _ssh_env_cache +lockdir=/tmp/oh-my-zsh-ssh-agent.lock + +while true; do + if mkdir "$lockdir" 2>/dev/null + then # directory did not exist, but was created successfully + trap 'rm -rf "$lockdir"' 0 # remove directory when script finishes + break # continue with script + else + sleep 0.1 # sleep for 0.2 and try again + fi +done + +typeset _ssh_env_cache function _start_agent() { local lifetime @@ -56,10 +68,7 @@ function _add_identities() { # Get the filename to store/lookup the environment from _ssh_env_cache="$HOME/.ssh/environment-$SHORT_HOST" -# test if agent-forwarding is enabled -zstyle -b :omz:plugins:ssh-agent agent-forwarding _agent_forwarding - -if [[ $_agent_forwarding == "yes" && -n "$SSH_AUTH_SOCK" ]]; then +if zstyle -t :omz:plugins:ssh-agent agent-forwarding && [[ -n "$SSH_AUTH_SOCK" ]]; then # Add a nifty symlink for screen/tmux if agent forwarding [[ -L $SSH_AUTH_SOCK ]] || ln -sf "$SSH_AUTH_SOCK" /tmp/ssh-agent-$USERNAME-screen elif [[ -f "$_ssh_env_cache" ]]; then @@ -73,12 +82,16 @@ elif [[ -f "$_ssh_env_cache" ]]; then ps $FILTER | grep ssh-agent | grep -q $SSH_AGENT_PID || { _start_agent } -else +elif [[ -d $HOME/.ssh ]]; then _start_agent fi -_add_identities +if ! zstyle -t :omz:plugins:ssh-agent lazy; then + _add_identities +fi # tidy up after ourselves -unset _agent_forwarding _ssh_env_cache +unset _ssh_env_cache unfunction _start_agent _add_identities + +rm -rf "$lockdir"