add ssh-find-agent

.config/ssh-find-agent.sh

@@ -0,0 +1,258 @@
+#!/bin/bash
+
+# Copyright (C) 2011 by Wayne Walker <wwalker@solid-constructs.com>
+#
+# Released under one of the versions of the MIT License.
+#
+# Copyright (C) 2011 by Wayne Walker <wwalker@solid-constructs.com>
+#
+# 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.
+
+sfa_init() {
+  _ssh_agent_sockets=()
+  _live_agent_list=()
+  _live_agent_sock_list=()
+  _sorted_live_agent_list=()
+
+  # Set $sfa_path array to the dirs to search for ssh-agent sockets
+  sfa_set_path
+
+  if ! command -v 'timeout' &>/dev/null; then
+    printf "ssh-find-agent.sh: 'timeout' command could not be found.\n"
+    printf "  Please install 'coreutils' via your system's package manager.\n"
+  fi
+}
+
+# Allow users to override the default path to search for ssh-agent sockets
+# The first of the variable found is used to set the path:
+#   SSH_FIND_AGENT_PATH (colon separated dir list)
+#   _TMPDIR_OVERRIDE for legacy compatibility
+#   TMPDIR (if set) (plus /tmp due to ssh bug)
+sfa_set_path() {
+  sfa_path=()
+  if [[ -n "$SSH_FIND_AGENT_PATH" ]]; then
+    IFS=':' read -r -a sfa_path <<<"$SSH_FIND_AGENT_PATH"
+  else
+    # Maintain backwards compatibility with the old _TMPDIR_OVERRIDE variable
+    if [[ -n "$_TMPDIR_OVERRIDE" ]]; then
+      sfa_path=("$_TMPDIR_OVERRIDE")
+    else
+      if [[ -n "$TMPDIR" ]]; then
+        sfa_path=("/tmp" "$TMPDIR")
+      else
+        sfa_path=("/tmp")
+      fi
+    fi
+  fi
+}
+
+sfa_err() {
+  # shellcheck disable=SC2059
+  printf "$@" 1>&2
+}
+
+sfa_debug() {
+  if ((_DEBUG > 0)); then
+    sfa_err "$@" 1>&2
+  fi
+}
+
+sfa_find_all_agent_sockets() {
+  _ssh_agent_sockets=$(
+    find "${sfa_path[@]}" -maxdepth 2 -type s -name agent.\* 2>/dev/null | grep '/ssh-.*/agent.*'
+    find "${sfa_path[@]}" -maxdepth 2 -type s -name S.gpg-agent.ssh 2>/dev/null | grep '/gpg-.*/S.gpg-agent.ssh'
+    find "${sfa_path[@]}" -maxdepth 2 -type s -name ssh 2>/dev/null | grep '/keyring-.*/ssh$'
+    find "${sfa_path[@]}" -maxdepth 2 -type s -regex '.*/ssh-.*/agent..*$' 2>/dev/null
+  )
+  sfa_debug "$_ssh_agent_sockets"
+}
+
+sfa_test_agent_socket() {
+  local socket=$1
+  local output
+  output=$(SSH_AUTH_SOCK=$socket timeout 0.4 ssh-add -l 2>&1)
+  result=$?
+
+  [[ "$output" == "error fetching identities: communication with agent failed" ]] && result=2
+  sfa_debug $result
+
+  case $result in
+    0 | 1 | 141)
+      # contactible and has keys loaded
+      {
+        OIFS="$IFS"
+        IFS=$'\n'
+        # shellcheck disable=SC2207
+        _keys=($(SSH_AUTH_SOCK=$socket ssh-add -l 2>/dev/null))
+        IFS="$OIFS"
+      }
+      _live_agent_list+=("${#_keys[@]}:$socket")
+      return 0
+      ;;
+    2 | 124)
+      # socket is dead, delete it
+      sfa_err 'socket (%s) is dead, removing it.\n' "$socket"
+      sfa_debug "rm -rf ${socket%/*}"
+      rm -rf "${socket%/*}"
+      ;;
+    125 | 126 | 127)
+      sfa_err 'timeout returned <%s>\n' "$result" 1>&2
+      ;;
+    *)
+      sfa_err 'Unknown failure timeout returned <%s>\n' "$result" 1>&2
+      ;;
+  esac
+
+  case $result in
+    0 | 1)
+      _live_agent_list+=("$_key_count:$socket")
+      return 0
+      ;;
+  esac
+
+  return 1
+}
+
+sfa_verify_sockets() {
+  for i in $_ssh_agent_sockets; do
+    sfa_test_agent_socket "$i"
+  done
+}
+
+sfa_fingerprints() {
+  local file="$1"
+  while read -r l; do
+    [[ -n "$l" && ${l##\#} = "$l" ]] && ssh-keygen -l -f /dev/stdin <<<"$l"
+  done <"$file"
+}
+
+sfa_print_choose_menu() {
+  # find all the apparent socket files
+  # the sockets go into $_ssh_agent_sockets[]
+  sfa_find_all_agent_sockets
+
+  # verify each socket, discarding if dead
+  # the live sockets go into $_live_agent_list[]
+  sfa_verify_sockets
+  sfa_debug '<%s>\n' "${_live_agent_list[@]}"
+
+  # shellcheck disable=SC2207
+  IFS=$'\n' _sorted_live_agent_list=($(sort -u <<<"${_live_agent_list[*]}"))
+  unset IFS
+
+  sfa_debug "SORTED:\n"
+  sfa_debug '    <%s>\n' "${_sorted_live_agent_list[@]}"
+
+  local i=0
+  local sock
+
+  for agent in "${_sorted_live_agent_list[@]}"; do
+    i=$((i + 1))
+    sock=${agent/*:/}
+    if [[ "$1" = "-i" ]]; then
+      _live_agent_sock_list[$i]=$sock
+
+      printf '#%i)\n' "$i"
+      printf '    export SSH_AUTH_SOCK=%s\n' "$sock"
+      # Get all the forwarded keys for this agent, parse them and print them
+      SSH_AUTH_SOCK=$sock ssh-add -l 2>&1 |
+        grep -v 'error fetching identities for protocol 1: agent refused operation' |
+        while IFS= read -r key; do
+          parts=("$key")
+          key_size="${parts[0]}"
+          fingerprint="${parts[1]}"
+          remote_name="${parts[2]}"
+          key_type="${parts[3]}"
+          printf '        %s %s\t%s\t%s\n' "$key_size" "$key_type" "$remote_name" "$fingerprint"
+        done
+    else
+      printf '%s\n' "$sock"
+    fi
+  done
+}
+
+sfa_set_ssh_agent_socket() {
+  case $1 in
+    -c | --choose)
+      sfa_print_choose_menu -i
+
+      ((0 == ${#_live_agent_list[@]})) && {
+        sfa_err 'No agents found.\n'
+        return 1
+      }
+
+      read -p "Choose (1-${#_live_agent_sock_list[@]})? " -r choice
+      if [ "$choice" -eq "$choice" ]; then
+        [[ -z "${_live_agent_sock_list[$choice]}" ]] && {
+          sfa_err 'Invalid choice.\n'
+          return 1
+        }
+        printf 'Setting export SSH_AUTH_SOCK=%s\n' "${_live_agent_sock_list[$choice]}"
+        export SSH_AUTH_SOCK=${_live_agent_sock_list[$choice]}
+      fi
+      ;;
+    -a | --auto)
+      # Choose the last one, as they are sorted numerically by how many keys they have
+      sock=$(sfa_print_choose_menu | tail -n -1)
+      [[ -z "$sock" ]] && return 1
+      sfa_debug 'export SSH_AUTH_SOCK=%s\n' "$sock"
+      export SSH_AUTH_SOCK=$sock
+      ;;
+    *)
+      sfa_usage
+      ;;
+  esac
+
+  # set agent pid - this is unreliable as the pid may be of the child rather than the agent
+  if [ -n "$SSH_AUTH_SOCK" ]; then
+    export SSH_AGENT_PID=$(($(basename "$SSH_AUTH_SOCK" | cut -d. -f2) + 1))
+  fi
+
+  return 0
+}
+
+sfa_usage() {
+  sfa_err 'ssh-find-agent <[-c|--choose|-a|--auto|-h|--help]>\n'
+  return 1
+}
+
+# Renamed for https://github.com/wwalker/ssh-find-agent/issues/12
+ssh_find_agent() {
+  sfa_init
+
+  case $1 in
+    -c | --choose | -a | --auto)
+      sfa_set_ssh_agent_socket "$1"
+      return $?
+      ;;
+    -l | --list)
+      sfa_print_choose_menu -i
+      ;;
+    *)
+      sfa_usage
+      ;;
+  esac
+}
+
+# Original function name is still supported.
+# https://github.com/wwalker/ssh-find-agent/issues/12 points out that I
+# should use ssh_find_agent() for best compatibility.
+ssh-find-agent() {
+  ssh_find_agent "$@"
+}

home.nix

@@ -4,6 +4,16 @@
   home.username = "felix";
   home.homeDirectory = "/home/felix";
 
+  home.file.".config/ssh-find-agent.sh".source = ./.config/ssh-find-agent.sh;
+  # link the configuration file in current directory to the specified location in home directory
+
+  # link all files in `./scripts` to `~/.config/i3/scripts`
+  # home.file.".config/i3/scripts" = {
+  #   source = ./scripts;
+  #   recursive = true;   # link recursively
+  #   executable = true;  # make all files executable
+  # };
+
   # encode the file content in nix configuration file directly
   # home.file.".xxx".text = ''
   #     xxx