From 39f3516d7f57397cb61c5a28d3d199ad9bb1a719 Mon Sep 17 00:00:00 2001 From: Daniel Kahn Gillmor Date: Thu, 21 Aug 2008 01:45:39 -0400 Subject: [PATCH] made monkeysphere subkey-to-ssh-agent more user-friendly. --- src/common | 46 ++++++++++++++++++++++++++++++++++++++ src/monkeysphere | 57 +++++++++++++++++++++++++++++++++++++++++++----- 2 files changed, 97 insertions(+), 6 deletions(-) diff --git a/src/common b/src/common index 6a62080..44bdb67 100644 --- a/src/common +++ b/src/common @@ -120,6 +120,52 @@ passphrase_prompt() { fi } +test_gnu_dummy_s2k_extension() { + +# this block contains a demonstration private key that has had the +# primary key stripped out using the GNU S2K extension known as +# "gnu-dummy" (see /usr/share/doc/gnupg/DETAILS.gz). The subkey is +# present in cleartext, however. + +# openpgp2ssh will be able to deal with this based on whether the +# local copy of GnuTLS contains read_s2k support that can handle it. + +# read up on that here: + +# http://lists.gnu.org/archive/html/gnutls-devel/2008-08/msg00005.html + +echo " +-----BEGIN PGP PRIVATE KEY BLOCK----- +Version: GnuPG v1.4.9 (GNU/Linux) + +lQCVBEO3YdABBACRqqEnucag4+vyZny2M67Pai5+5suIRRvY+Ly8Ms5MvgCi3EVV +xT05O/+0ShiRaf+QicCOFrhbU9PZzzU+seEvkeW2UCu4dQfILkmj+HBEIltGnHr3 +G0yegHj5pnqrcezERURf2e17gGFWX91cXB9Cm721FPXczuKraphKwCA9PwARAQAB +/gNlAkdOVQG0OURlbW9uc3RyYXRpb24gS2V5IGZvciBTMksgR05VIGV4dGVuc2lv +biAxMDAxIC0tIGdudS1kdW1teYi8BBMBAgAmBQJDt2HQAhsDBQkB4TOABgsJCAcD +AgQVAggDBBYCAwECHgECF4AACgkQQZUwSa4UDezTOQP/TMQXUVrWzHYZGopoPZ2+ +ZS3qddiznBHsgb7MGYg1KlTiVJSroDUBCHIUJvdQKZV9zrzrFl47D07x6hGyUPHV +aZXvuITW8t1o5MMHkCy3pmJ2KgfDvdUxrBvLfgPMICA4c6zA0mWquee43syEW9NY +g3q61iPlQwD1J1kX1wlimLCdAdgEQ7dh0AEEANAwa63zlQbuy1Meliy8otwiOa+a +mH6pxxUgUNggjyjO5qx+rl25mMjvGIRX4/L1QwIBXJBVi3SgvJW1COZxZqBYqj9U +8HVT07mWKFEDf0rZLeUE2jTm16cF9fcW4DQhW+sfYm+hi2sY3HeMuwlUBK9KHfW2 ++bGeDzVZ4pqfUEudABEBAAEAA/0bemib+wxub9IyVFUp7nPobjQC83qxLSNzrGI/ +RHzgu/5CQi4tfLOnwbcQsLELfker2hYnjsLrT9PURqK4F7udrWEoZ1I1LymOtLG/ +4tNZ7Mnul3wRC2tCn7FKx8sGJwGh/3li8vZ6ALVJAyOia5TZ/buX0+QZzt6+hPKk +7MU1WQIA4bUBjtrsqDwro94DvPj3/jBnMZbXr6WZIItLNeVDUcM8oHL807Am97K1 +ueO/f6v1sGAHG6lVPTmtekqPSTWBfwIA7CGFvEyvSALfB8NUa6jtk27NCiw0csql +kuhCmwXGMVOiryKEfegkIahf2bAd/gnWHPrpWp7bUE20v8YoW22I4wIAhnm5Wr5Q +Sy7EHDUxmJm5TzadFp9gq08qNzHBpXSYXXJ3JuWcL1/awUqp3tE1I6zZ0hZ38Ia6 +SdBMN88idnhDPqPoiKUEGAECAA8FAkO3YdACGyAFCQHhM4AACgkQQZUwSa4UDezm +vQP/ZhK+2ly9oI2z7ZcNC/BJRch0/ybQ3haahII8pXXmOThpZohr/LUgoWgCZdXg +vP6yiszNk2tIs8KphCAw7Lw/qzDC2hEORjWO4f46qk73RAgSqG/GyzI4ltWiDhqn +vnQCFl3+QFSe4zinqykHnLwGPMXv428d/ZjkIc2ju8dRsn4= +=CR5w +-----END PGP PRIVATE KEY BLOCK----- +" | openpgp2ssh 4129E89D17C1D591 >/dev/null 2>/dev/null + +} + # remove all lines with specified string from specified file remove_line() { local file diff --git a/src/monkeysphere b/src/monkeysphere index 8f44bf5..2ca3636 100755 --- a/src/monkeysphere +++ b/src/monkeysphere @@ -182,25 +182,63 @@ function subkey_to_ssh_agent() { local subkey local workingdir local kname + local sshaddresponse + local keysuccess + # if there's no agent running, don't bother: + if [ -z "$SSH_AUTH_SOCK" ] || ! which ssh-add >/dev/null ; then + failure "No ssh-agent available." + fi + + # and if it looks like it's running, but we can't actually talk to + # it, bail out: + ssh-add -l >/dev/null + sshaddresponse="$?" + if [ "$sshaddresponse" = "2" ]; then + failure "Could not connect to ssh-agent" + fi + # get list of secret keys (to work around https://bugs.g10code.com/gnupg/issue945): secretkeys=$(gpg --list-secret-keys --with-colons --fixed-list-mode --fingerprint | grep '^fpr:' | cut -f10 -d: | awk '{ print "0x" $1 "!" }') + + if [ -z "$secretkeys" ]; then + failure "You have no secret keys in your keyring! +You might want to 'gpg --gen-key'" + fi authsubkeys=$(gpg --list-secret-keys --with-colons --fixed-list-mode --fingerprint --fingerprint $secretkeys | cut -f1,5,10,12 -d: | grep -A1 '^ssb:[^:]*::[^:]*a[^:]*$' | grep '^fpr::' | cut -f3 -d: | sort -u) + if [ -z "$authsubkeys" ]; then + failure "no authentication-capable subkeys available. +You might want to 'monkeysphere gen-subkey'" + fi + + if ! test_gnu_dummy_s2k_extension ; then + failure "Your version of GnuTLS does not seem capable of using with gpg's exported subkeys. +You may want to consider patching or upgrading. + +For more details, see: + http://lists.gnu.org/archive/html/gnutls-devel/2008-08/msg00005.html" + fi + workingdir=$(mktemp -d) umask 077 mkfifo "$workingdir/passphrase" + keysuccess=1 # FIXME: we're currently allowing any other options to get passed # through to ssh-add. should we limit it to known ones? For # example: -d or -c and/or -t - # FIXME: how do we know if we succeeded or failed? ssh-add gives - # weird return values under setsid, and if there are more than one - for subkey in $authsubkeys; do - kname="MonkeySphere Key $subkey" + # choose a label by which this key will be known in the agent: + # we are labelling the key by User ID instead of by + # fingerprint, but filtering out all / characters to make sure + # the filename is legit. + + primaryuid=$(gpg --with-colons --list-key "0x${subkey}!" | grep '^pub:' | cut -f10 -d: | tr -d /) + + kname="[monkeysphere] $primaryuid" if [ "$1" = '-d' ]; then # we're removing the subkey: @@ -214,13 +252,20 @@ function subkey_to_ssh_agent() { --export-secret-subkeys "0x${subkey}!" | openpgp2ssh "$subkey" > "$workingdir/$kname" & (cd "$workingdir" && DISPLAY=nosuchdisplay SSH_ASKPASS=/bin/false ssh-add "$@" "$kname"