move src/subcommands to srv/share, and add common file to src/share (update Makefile as well)

1 files changed, 237 insertions, 0 deletions

diff --git a/src/share/m/ssh_proxycommand b/src/share/m/ssh_proxycommand
new file mode 100644
index 0000000..7239c7a
--- /dev/null
+++ b/src/share/m/ssh_proxycommand
@@ -0,0 +1,237 @@
+# -*-shell-script-*-
+# This should be sourced by bash (though we welcome changes to make it POSIX sh compliant)
+
+# monkeysphere-ssh-proxycommand: MonkeySphere ssh ProxyCommand hook
+#
+# The monkeysphere scripts are written by:
+# Jameson Rollins <jrollins@finestructure.net>
+# Daniel Kahn Gillmor <dkg@fifthhorseman.net>
+#
+# They are Copyright 2008-2009, and are all released under the GPL,
+# version 3 or later.
+
+# This is meant to be run as an ssh ProxyCommand to initiate a
+# monkeysphere known_hosts update before an ssh connection to host is
+# established.  Can be added to ~/.ssh/config as follows:
+#  ProxyCommand monkeysphere-ssh-proxycommand %h %p
+
+ssh_proxycommand() {
+
+# "marginal case" ouput in the case that there is not a full
+# validation path to the host
+output_no_valid_key() {
+    local sshKeyOffered
+    local userID
+    local type
+    local validity
+    local keyid
+    local uidfpr
+    local usage
+    local sshKeyGPG
+    local tmpkey
+    local sshFingerprint
+    local gpgSigOut
+
+    userID="ssh://${HOSTP}"
+
+    log "-------------------- Monkeysphere warning -------------------"
+    log "Monkeysphere found OpenPGP keys for this hostname, but none had full validity."
+
+    # retrieve the actual ssh key
+    sshKeyOffered=$(ssh-keyscan -t rsa -p "$PORT" "$HOST" 2>/dev/null | awk '{ print $2, $3 }')
+    # FIXME: should we do any checks for failed keyscans, eg. host not
+    # found?
+
+    # get the gpg info for userid
+    gpgOut=$(gpg --list-key --fixed-list-mode --with-colon \
+	--with-fingerprint --with-fingerprint \
+	="$userID" 2>/dev/null)
+
+    # find all 'pub' and 'sub' lines in the gpg output, which each
+    # represent a retrieved key for the user ID
+    echo "$gpgOut" | cut -d: -f1,2,5,10,12 | \
+    while IFS=: read -r type validity keyid uidfpr usage ; do
+	case $type in
+	    'pub'|'sub')
+		# get the ssh key of the gpg key
+		sshKeyGPG=$(gpg2ssh "$keyid")
+
+		# if one of keys found matches the one offered by the
+		# host, then output info
+		if [ "$sshKeyGPG" = "$sshKeyOffered" ] ; then
+		    log "An OpenPGP key matching the ssh key offered by the host was found:"
+		    log
+
+		    # do some crazy "Here Strings" redirection to get the key to
+		    # ssh-keygen, since it doesn't read from stdin cleanly
+		    sshFingerprint=$(ssh-keygen -l -f /dev/stdin \
+			<<<$(echo "$sshKeyGPG") | \
+			awk '{ print $2 }')
+
+		    # get the sigs for the matching key
+		    gpgSigOut=$(gpg --check-sigs \
+			--list-options show-uid-validity \
+			"$keyid")
+
+		    # output the sigs, but only those on the user ID
+		    # we are looking for
+		    echo "$gpgSigOut" | awk '
+{
+if (match($0,"^pub")) {	print; }
+if (match($0,"^uid")) { ok=0; }
+if (match($0,"^uid.*'$userID'$")) { ok=1; print; }
+if (ok) { if (match($0,"^sig")) { print; } }
+}
+' >&2
+		    log
+
+		    # output the other user IDs for reference
+		    if (echo "$gpgSigOut" | grep "^uid" | grep -v -q "$userID") ; then
+			log "Other user IDs on this key:"
+			echo "$gpgSigOut" | grep "^uid" | grep -v "$userID" >&2
+			log
+		    fi
+
+		    # output ssh fingerprint
+		    log "RSA key fingerprint is ${sshFingerprint}."
+
+		    # this whole process is in a "while read"
+		    # subshell.  the only way to get information out
+		    # of the subshell is to change the return code.
+		    # therefore we return 1 here to indicate that a
+		    # matching gpg key was found for the ssh key
+		    # offered by the host
+		    return 1
+		fi
+		;;
+	esac
+    done
+
+    # if no key match was made (and the "while read" subshell returned
+    # 1) output how many keys were found
+    if (($? != 1)) ; then
+	log "None of the found keys matched the key offered by the host."
+	log "Run the following command for more info about the found keys:"
+	log "gpg --check-sigs --list-options show-uid-validity =${userID}"
+	# FIXME: should we do anything extra here if the retrieved
+	# host key is actually in the known_hosts file and the ssh
+	# connection will succeed?  Should the user be warned?
+	# prompted?
+    fi
+
+    log "-------------------- ssh continues below --------------------"
+}
+
+########################################################################
+
+# export the monkeysphere log level
+export MONKEYSPHERE_LOG_LEVEL
+
+if [ "$1" = '--no-connect' ] ; then
+    NO_CONNECT='true'
+    shift 1
+fi
+
+HOST="$1"
+PORT="$2"
+
+if [ -z "$HOST" ] ; then
+    log "Host not specified."
+    usage
+    exit 255
+fi
+if [ -z "$PORT" ] ; then
+    PORT=22
+fi
+
+# set the host URI
+if [ "$PORT" != '22' ] ; then
+    HOSTP="${HOST}:${PORT}"
+else
+    HOSTP="${HOST}"
+fi
+URI="ssh://${HOSTP}"
+
+# specify keyserver checking.  the behavior of this proxy command is
+# intentionally different than that of running monkeyesphere normally,
+# and keyserver checking is intentionally done under certain
+# circumstances.  This can be overridden by setting the
+# MONKEYSPHERE_CHECK_KEYSERVER environment variable.
+
+# if the host is in the gpg keyring...
+if gpg --list-key ="${URI}" 2>&1 >/dev/null ; then
+    # do not check the keyserver
+    CHECK_KEYSERVER="false"
+
+# if the host is NOT in the keyring...
+else
+    # if the host key is found in the known_hosts file...
+    # FIXME: this only works for default known_hosts location
+    hostKey=$(ssh-keygen -F "$HOST" 2>/dev/null)
+
+    if [ "$hostKey" ] ; then
+	# do not check the keyserver
+	# FIXME: more nuanced checking should be done here to properly
+	# take into consideration hosts that join monkeysphere by
+	# converting an existing and known ssh key
+	CHECK_KEYSERVER="false"
+
+    # if the host key is not found in the known_hosts file...
+    else
+	# check the keyserver
+	CHECK_KEYSERVER="true"
+    fi
+fi
+# set and export the variable for use by monkeysphere
+MONKEYSPHERE_CHECK_KEYSERVER=${MONKEYSPHERE_CHECK_KEYSERVER:="$CHECK_KEYSERVER"}
+export MONKEYSPHERE_CHECK_KEYSERVER
+
+# update the known_hosts file for the host
+monkeysphere update-known_hosts "$HOSTP"
+
+# output on depending on the return of the update-known_hosts
+# subcommand, which is (ultimately) the return code of the
+# update_known_hosts function in common
+case $? in
+    0)
+	# acceptable host key found so continue to ssh
+	true
+	;;
+    1)
+	# no hosts at all found so also continue (drop through to
+	# regular ssh host verification)
+	true
+	;;
+    2)
+	# at least one *bad* host key (and no good host keys) was
+	# found, so output some usefull information
+	output_no_valid_key
+	;;
+    *)
+	# anything else drop through
+	true
+	;;
+esac
+
+# FIXME: what about the case where monkeysphere successfully finds a
+# valid key for the host and adds it to the known_hosts file, but a
+# different non-monkeysphere key for the host already exists in the
+# known_hosts, and it is this non-ms key that is offered by the host?
+# monkeysphere will succeed, and the ssh connection will succeed, and
+# the user will be left with the impression that they are dealing with
+# a OpenPGP/PKI host key when in fact they are not.  should we use
+# ssh-keyscan to compare the keys first?
+
+# exec a netcat passthrough to host for the ssh connection
+if [ -z "$NO_CONNECT" ] ; then
+    if (which nc 2>/dev/null >/dev/null); then
+	exec nc "$HOST" "$PORT"
+    elif (which socat 2>/dev/null >/dev/null); then
+	exec socat STDIO "TCP:$HOST:$PORT"
+    else
+	echo "Neither netcat nor socat found -- could not complete monkeysphere-ssh-proxycommand connection to $HOST:$PORT" >&2
+	exit 255
+    fi
+fi
+
+}