win-ssh-agent.sh

#!/bin/sh

# Start ssh-agent and register environment variables permanently in HKCU.
# Copyright (C) 2013 YAEGASHI Takeshi <t@keshi.org>

# Use a fixed path for the ssh-agent socket endpoint.
# SSH_FIXED_SOCK="/tmp/ssh-agent-$(id -u).sock"

eval $(ssh-agent -k)

if test -n "$SSH_FIXED_SOCK"; then
        rm -f "$SSH_FIXED_SOCK"
        eval $(ssh-agent -a "$SSH_FIXED_SOCK")
else
        eval $(ssh-agent)
fi

PID=$SSH_AGENT_PID

case "$(uname -s)" in
CYGWIN*)
        SOCK=$(cygpath --windows "$SSH_AUTH_SOCK") ;;
*)
        SOCK=$(cmd //c echo "$SSH_AUTH_SOCK") ;;
esac

echo "Agent endpoint $SOCK"
echo

cat <<EOF | powershell -command -
[Environment]::SetEnvironmentVariable("SSH_AGENT_PID", "$PID", "User")
[Environment]::SetEnvironmentVariable("SSH_AUTH_SOCK", "$SOCK", "User")

# P/Invoke SendMessageTimeout(): Broadcast WM_SETTINGCHANGE (0x1a)
# to notify other processes of the environment variable changes.
\$WinAPI = add-type -Name WinAPI -PassThru -MemberDefinition @"
[DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]
public static extern IntPtr SendMessageTimeout(
        IntPtr hWnd, uint Msg, UIntPtr wParam, string lParam,
        uint fuFlags, uint uTimeout, out UIntPtr lpdwResult);
"@
\$result = [UIntPtr]::Zero
\$ret = \$WinAPI::SendMessageTimeout([IntPtr]0xffff, 0x1a,
        [UIntPtr]::Zero, "Environment", 2, 5000, [ref]\$result)
EOF

while ! ssh-add; do
        echo "Try again... (or ^C to abort)"
done

echo
echo "Agent added fingerprint"
ssh-add -l

echo
echo -n "Press ENTER to exit... "

read