3 # Shared sh functions for the monkeysphere
6 # Jameson Rollins <jrollins@fifthhorseman.net>
7 # Jamie McClelland <jm@mayfirst.org>
8 # Daniel Kahn Gillmor <dkg@fifthhorseman.net>
10 # Copyright 2008, released under the GPL, version 3 or later
12 # all-caps variables are meant to be user supplied (ie. from config
13 # file) and are considered global
15 ########################################################################
19 ETC="/etc/monkeysphere"
22 ########################################################################
25 # failure function. exits with code 255, unless specified otherwise.
31 # write output to stderr based on specified LOG_LEVEL the first
32 # parameter is the priority of the output, and everything else is what
41 # don't include SILENT in alllevels: it's handled separately
42 # list in decreasing verbosity (all caps).
43 # separate with $IFS explicitly, since we do some fancy footwork
45 alllevels="DEBUG${IFS}VERBOSE${IFS}INFO${IFS}ERROR"
47 # translate lowers to uppers in global log level
48 LOG_LEVEL=$(echo "$LOG_LEVEL" | tr "[:lower:]" "[:upper:]")
50 # just go ahead and return if the log level is silent
51 if [ "$LOG_LEVEL" = 'SILENT' ] ; then
55 for level in $alllevels ; do
56 if [ "$LOG_LEVEL" = "$level" ] ; then
60 if [ -z "$found" ] ; then
65 # get priority from first parameter, translating all lower to
67 priority=$(echo "$1" | tr "[:lower:]" "[:upper:]")
70 # scan over available levels
71 for level in $alllevels ; do
72 # output if the log level matches, set output to true
73 # this will output for all subsequent loops as well.
74 if [ "$LOG_LEVEL" = "$level" ] ; then
77 if [ "$priority" = "$level" -a "$output" = 'true' ] ; then
84 # cut out all comments(#) and blank lines from standard input
86 grep -v -e "^[[:space:]]*#" -e '^$' "$1"
89 # cut a specified line from standard input
91 head --line="$1" "$2" | tail -1
94 # this is a wrapper for doing lock functions.
96 # it lets us depend on either lockfile-progs (preferred) or procmail's
97 # lockfile, and should
99 local use_lockfileprogs=true
103 if ! ( which lockfile-create >/dev/null 2>/dev/null ) ; then
104 if ! ( which lockfile >/dev/null ); then
105 failure "Neither lockfile-create nor lockfile are in the path!"
112 if [ -n "$use_lockfileprogs" ] ; then
113 lockfile-create "$file" || failure "unable to lock '$file'"
115 lockfile -r 20 "${file}.lock" || failure "unable to lock '$file'"
119 if [ -n "$use_lockfileprogs" ] ; then
120 lockfile-touch --oneshot "$file"
126 if [ -n "$use_lockfileprogs" ] ; then
127 lockfile-remove "$file"
133 failure "bad argument for lock subfunction '$action'"
138 # for portability, between gnu date and BSD date.
139 # arguments should be: number longunits format
141 # e.g. advance_date 20 seconds +%F
149 # try things the GNU way first
150 if date -d "$number $longunits" "$format" >&/dev/null ; then
151 date -d "$number $longunits" "$format"
153 # otherwise, convert to (a limited version of) BSD date syntax:
177 # this is a longshot, and will likely fail; oh well.
178 shortunits="$longunits"
180 date "-v+${number}${shortunits}" "$format"
185 # check that characters are in a string (in an AND fashion).
186 # used for checking key capability
187 # check_capability capability a [b...]
196 if echo "$usage" | grep -q -v "$capcheck" ; then
205 md5sum "$1" 2> /dev/null
208 # convert escaped characters in pipeline from gpg output back into
210 # FIXME: undo all escape character translation in with-colons gpg
216 # convert nasty chars into gpg-friendly form in pipeline
217 # FIXME: escape everything, not just colons!
222 # prompt for GPG-formatted expiration, and emit result on stdout
223 get_gpg_expiration() {
228 if [ -z "$keyExpire" ]; then
230 Please specify how long the key should be valid.
231 0 = key does not expire
232 <n> = key expires in n days
233 <n>w = key expires in n weeks
234 <n>m = key expires in n months
235 <n>y = key expires in n years
237 while [ -z "$keyExpire" ] ; do
238 read -p "Key is valid for? (0) " keyExpire
239 if ! test_gpg_expire ${keyExpire:=0} ; then
240 echo "invalid value" >&2
244 elif ! test_gpg_expire "$keyExpire" ; then
245 failure "invalid key expiration value '$keyExpire'."
251 passphrase_prompt() {
256 if [ "$DISPLAY" ] && which "${SSH_ASKPASS:-ssh-askpass}" >/dev/null; then
257 "${SSH_ASKPASS:-ssh-askpass}" "$prompt" > "$fifo"
259 read -s -p "$prompt" PASS
260 # Uses the builtin echo, so should not put the passphrase into
261 # the process table. I think. --dkg
262 echo "$PASS" > "$fifo"
266 test_gnu_dummy_s2k_extension() {
268 # this block contains a demonstration private key that has had the
269 # primary key stripped out using the GNU S2K extension known as
270 # "gnu-dummy" (see /usr/share/doc/gnupg/DETAILS.gz). The subkey is
271 # present in cleartext, however.
273 # openpgp2ssh will be able to deal with this based on whether the
274 # local copy of GnuTLS contains read_s2k support that can handle it.
276 # read up on that here:
278 # http://lists.gnu.org/archive/html/gnutls-devel/2008-08/msg00005.html
281 -----BEGIN PGP PRIVATE KEY BLOCK-----
282 Version: GnuPG v1.4.9 (GNU/Linux)
284 lQCVBEO3YdABBACRqqEnucag4+vyZny2M67Pai5+5suIRRvY+Ly8Ms5MvgCi3EVV
285 xT05O/+0ShiRaf+QicCOFrhbU9PZzzU+seEvkeW2UCu4dQfILkmj+HBEIltGnHr3
286 G0yegHj5pnqrcezERURf2e17gGFWX91cXB9Cm721FPXczuKraphKwCA9PwARAQAB
287 /gNlAkdOVQG0OURlbW9uc3RyYXRpb24gS2V5IGZvciBTMksgR05VIGV4dGVuc2lv
288 biAxMDAxIC0tIGdudS1kdW1teYi8BBMBAgAmBQJDt2HQAhsDBQkB4TOABgsJCAcD
289 AgQVAggDBBYCAwECHgECF4AACgkQQZUwSa4UDezTOQP/TMQXUVrWzHYZGopoPZ2+
290 ZS3qddiznBHsgb7MGYg1KlTiVJSroDUBCHIUJvdQKZV9zrzrFl47D07x6hGyUPHV
291 aZXvuITW8t1o5MMHkCy3pmJ2KgfDvdUxrBvLfgPMICA4c6zA0mWquee43syEW9NY
292 g3q61iPlQwD1J1kX1wlimLCdAdgEQ7dh0AEEANAwa63zlQbuy1Meliy8otwiOa+a
293 mH6pxxUgUNggjyjO5qx+rl25mMjvGIRX4/L1QwIBXJBVi3SgvJW1COZxZqBYqj9U
294 8HVT07mWKFEDf0rZLeUE2jTm16cF9fcW4DQhW+sfYm+hi2sY3HeMuwlUBK9KHfW2
295 +bGeDzVZ4pqfUEudABEBAAEAA/0bemib+wxub9IyVFUp7nPobjQC83qxLSNzrGI/
296 RHzgu/5CQi4tfLOnwbcQsLELfker2hYnjsLrT9PURqK4F7udrWEoZ1I1LymOtLG/
297 4tNZ7Mnul3wRC2tCn7FKx8sGJwGh/3li8vZ6ALVJAyOia5TZ/buX0+QZzt6+hPKk
298 7MU1WQIA4bUBjtrsqDwro94DvPj3/jBnMZbXr6WZIItLNeVDUcM8oHL807Am97K1
299 ueO/f6v1sGAHG6lVPTmtekqPSTWBfwIA7CGFvEyvSALfB8NUa6jtk27NCiw0csql
300 kuhCmwXGMVOiryKEfegkIahf2bAd/gnWHPrpWp7bUE20v8YoW22I4wIAhnm5Wr5Q
301 Sy7EHDUxmJm5TzadFp9gq08qNzHBpXSYXXJ3JuWcL1/awUqp3tE1I6zZ0hZ38Ia6
302 SdBMN88idnhDPqPoiKUEGAECAA8FAkO3YdACGyAFCQHhM4AACgkQQZUwSa4UDezm
303 vQP/ZhK+2ly9oI2z7ZcNC/BJRch0/ybQ3haahII8pXXmOThpZohr/LUgoWgCZdXg
304 vP6yiszNk2tIs8KphCAw7Lw/qzDC2hEORjWO4f46qk73RAgSqG/GyzI4ltWiDhqn
305 vnQCFl3+QFSe4zinqykHnLwGPMXv428d/ZjkIc2ju8dRsn4=
307 -----END PGP PRIVATE KEY BLOCK-----
308 " | openpgp2ssh 4129E89D17C1D591 >/dev/null 2>/dev/null
312 # remove all lines with specified string from specified file
321 if [ -z "$file" -o -z "$string" ] ; then
325 if [ ! -e "$file" ] ; then
329 # if the string is in the file...
330 if grep -q -F "$string" "$file" 2> /dev/null ; then
331 tempfile=$(mktemp "${file}.XXXXXXX") || \
332 failure "Unable to make temp file '${file}.XXXXXXX'"
334 # remove the line with the string, and return 0
335 grep -v -F "$string" "$file" >"$tempfile"
336 cat "$tempfile" > "$file"
345 # remove all lines with MonkeySphere strings in file
346 remove_monkeysphere_lines() {
352 if [ -z "$file" ] ; then
356 if [ ! -e "$file" ] ; then
360 tempfile=$(mktemp "${file}.XXXXXXX") || \
361 failure "Could not make temporary file '${file}.XXXXXXX'."
363 egrep -v '^MonkeySphere[[:digit:]]{4}(-[[:digit:]]{2}){2}T[[:digit:]]{2}(:[[:digit:]]{2}){2}$' \
365 cat "$tempfile" > "$file"
369 # translate ssh-style path variables %h and %u
370 translate_ssh_variables() {
377 # get the user's home directory
378 userHome=$(getent passwd "$uname" | cut -d: -f6)
380 # translate '%u' to user name
381 path=${path/\%u/"$uname"}
382 # translate '%h' to user home directory
383 path=${path/\%h/"$userHome"}
388 # test that a string to conforms to GPG's expiration format
390 echo "$1" | egrep -q "^[0-9]+[mwy]?$"
393 # check that a file is properly owned, and that all it's parent
394 # directories are not group/other writable
395 check_key_file_permissions() {
402 # function to check that an octal corresponds to writability
404 [ "$1" -eq 2 -o "$1" -eq 3 -o "$1" -eq 6 -o "$1" -eq 7 ]
410 # return 0 is path does not exist
411 [ -e "$path" ] || return 0
413 owner=$(stat --format '%U' "$path")
414 access=$(stat --format '%a' "$path")
415 gAccess=$(echo "$access" | cut -c2)
416 oAccess=$(echo "$access" | cut -c3)
419 if [ "$owner" != "$user" -a "$owner" != 'root' ] ; then
423 # check group/other writability
424 if is_write "$gAccess" || is_write "$oAccess" ; then
428 if [ "$path" = '/' ] ; then
431 check_key_file_permissions $(dirname "$path")
435 ### CONVERSION UTILITIES
437 # output the ssh key for a given key ID
443 gpg --export "$keyID" | openpgp2ssh "$keyID" 2> /dev/null
446 # output known_hosts line from ssh key
455 echo -n "$key" | tr -d '\n'
456 echo " MonkeySphere${DATE}"
459 # output authorized_keys line from ssh key
460 ssh2authorized_keys() {
467 echo -n "$key" | tr -d '\n'
468 echo " MonkeySphere${DATE} ${userID}"
471 # convert key from gpg to ssh known_hosts format
479 # NOTE: it seems that ssh-keygen -R removes all comment fields from
480 # all lines in the known_hosts file. why?
481 # NOTE: just in case, the COMMENT can be matched with the
483 # '^MonkeySphere[[:digit:]]{4}(-[[:digit:]]{2}){2}T[[:digit:]]{2}(:[[:digit:]]{2}){2}$'
485 gpg2ssh "$keyID" | tr -d '\n'
486 echo " MonkeySphere${DATE}"
489 # convert key from gpg to ssh authorized_keys format
490 gpg2authorized_keys() {
497 # NOTE: just in case, the COMMENT can be matched with the
499 # '^MonkeySphere[[:digit:]]{4}(-[[:digit:]]{2}){2}T[[:digit:]]{2}(:[[:digit:]]{2}){2}$'
500 gpg2ssh "$keyID" | tr -d '\n'
501 echo " MonkeySphere${DATE} ${userID}"
506 # retrieve all keys with given user id from keyserver
507 # FIXME: need to figure out how to retrieve all matching keys
508 # (not just first N (5 in this case))
513 if [ "$CHECK_KEYSERVER" != 'true' ] ; then
519 log info " checking keyserver $KEYSERVER... "
521 gpg --quiet --batch --with-colons \
522 --command-fd 0 --keyserver "$KEYSERVER" \
523 --search ="$userID" > /dev/null 2>&1
526 # if the user is the monkeysphere user, then update the
527 # monkeysphere user's trustdb
528 if [ $(id -un) = "$MONKEYSPHERE_USER" ] ; then
529 gpg_authentication "--check-trustdb" > /dev/null 2>&1
535 ########################################################################
536 ### PROCESSING FUNCTIONS
538 # userid and key policy checking
539 # the following checks policy on the returned keys
540 # - checks that full key has appropriate valididy (u|f)
541 # - checks key has specified capability (REQUIRED_*_KEY_CAPABILITY)
542 # - checks that requested user ID has appropriate validity
543 # (see /usr/share/doc/gnupg/DETAILS.gz)
544 # output is one line for every found key, in the following format:
548 # "flag" is an acceptability flag, 0 = ok, 1 = bad
549 # "sshKey" is the translated gpg key
551 # all log output must go to stderr, as stdout is used to pass the
552 # flag:sshKey to the calling function.
554 # expects global variable: "MODE"
557 local requiredCapability
558 local requiredPubCapability
573 # set the required key capability based on the mode
574 if [ "$MODE" = 'known_hosts' ] ; then
575 requiredCapability="$REQUIRED_HOST_KEY_CAPABILITY"
576 elif [ "$MODE" = 'authorized_keys' ] ; then
577 requiredCapability="$REQUIRED_USER_KEY_CAPABILITY"
579 requiredPubCapability=$(echo "$requiredCapability" | tr "[:lower:]" "[:upper:]")
581 # fetch the user ID if necessary/requested
582 gpg_fetch_userid "$userID"
584 # output gpg info for (exact) userid and store
585 gpgOut=$(gpg --list-key --fixed-list-mode --with-colon \
586 --with-fingerprint --with-fingerprint \
587 ="$userID" 2>/dev/null)
589 # if the gpg query return code is not 0, return 1
590 if [ "$?" -ne 0 ] ; then
591 log verbose " no primary keys found."
595 # loop over all lines in the gpg output and process.
596 echo "$gpgOut" | cut -d: -f1,2,5,10,12 | \
597 while IFS=: read -r type validity keyid uidfpr usage ; do
598 # process based on record type
600 'pub') # primary keys
601 # new key, wipe the slate
608 log verbose " primary key found: $keyid"
610 # if overall key is not valid, skip
611 if [ "$validity" != 'u' -a "$validity" != 'f' ] ; then
612 log error " - unacceptable primary key validity ($validity)."
615 # if overall key is disabled, skip
616 if check_capability "$usage" 'D' ; then
617 log error " - key disabled."
620 # if overall key capability is not ok, skip
621 if ! check_capability "$usage" $requiredPubCapability ; then
622 log error " - unacceptable primary key capability ($usage)."
626 # mark overall key as ok
629 # mark primary key as ok if capability is ok
630 if check_capability "$usage" $requiredCapability ; then
635 if [ "$lastKey" != pub ] ; then
636 log error " - got a user ID after a sub key?! user IDs should only follow primary keys!"
639 # if an acceptable user ID was already found, skip
640 if [ "$uidOK" = 'true' ] ; then
643 # if the user ID does matches...
644 if [ "$(echo "$uidfpr" | gpg_unescape)" = "$userID" ] ; then
645 # and the user ID validity is ok
646 if [ "$validity" = 'u' -o "$validity" = 'f' ] ; then
647 # mark user ID acceptable
654 # output a line for the primary key
656 if [ "$keyOK" -a "$uidOK" -a "$lastKeyOK" ] ; then
657 log verbose " * acceptable primary key."
658 if [ -z "$sshKey" ] ; then
659 log error " ! primary key could not be translated (not RSA or DSA?)."
664 log error " - unacceptable primary key."
665 if [ -z "$sshKey" ] ; then
666 log error " ! primary key could not be translated (not RSA or DSA?)."
673 # unset acceptability of last key
678 # don't bother with sub keys if the primary key is not valid
679 if [ "$keyOK" != true ] ; then
683 # don't bother with sub keys if no user ID is acceptable:
684 if [ "$uidOK" != true ] ; then
688 # if sub key validity is not ok, skip
689 if [ "$validity" != 'u' -a "$validity" != 'f' ] ; then
692 # if sub key capability is not ok, skip
693 if ! check_capability "$usage" $requiredCapability ; then
700 'fpr') # key fingerprint
701 fingerprint="$uidfpr"
703 sshKey=$(gpg2ssh "$fingerprint")
705 # if the last key was the pub key, skip
706 if [ "$lastKey" = pub ] ; then
710 # output a line for the sub key
712 if [ "$keyOK" -a "$uidOK" -a "$lastKeyOK" ] ; then
713 log verbose " * acceptable sub key."
714 if [ -z "$sshKey" ] ; then
715 log error " ! sub key could not be translated (not RSA or DSA?)."
720 log error " - unacceptable sub key."
721 if [ -z "$sshKey" ] ; then
722 log error " ! sub key could not be translated (not RSA or DSA?)."
729 done | sort -t: -k1 -n -r
730 # NOTE: this last sort is important so that the "good" keys (key
731 # flag '0') come last. This is so that they take precedence when
732 # being processed in the key files over "bad" keys (key flag '1')
735 # process a single host in the known_host file
736 process_host_known_hosts() {
746 userID="ssh://${host}"
748 log verbose "processing: $host"
754 for line in $(process_user_id "${userID}") ; do
755 # note that key was found
758 ok=$(echo "$line" | cut -d: -f1)
759 sshKey=$(echo "$line" | cut -d: -f2)
761 if [ -z "$sshKey" ] ; then
765 # remove the old host key line, and note if removed
766 remove_line "$KNOWN_HOSTS" "$sshKey"
768 # if key OK, add new host line
769 if [ "$ok" -eq '0' ] ; then
770 # note that key was found ok
771 nKeysOK=$((nKeysOK+1))
774 if [ "$HASH_KNOWN_HOSTS" = 'true' ] ; then
775 # FIXME: this is really hackish cause ssh-keygen won't
776 # hash from stdin to stdout
777 tmpfile=$(mktemp ${TMPDIR:-/tmp}/tmp.XXXXXXXXXX)
778 ssh2known_hosts "$host" "$sshKey" > "$tmpfile"
779 ssh-keygen -H -f "$tmpfile" 2> /dev/null
780 cat "$tmpfile" >> "$KNOWN_HOSTS"
781 rm -f "$tmpfile" "${tmpfile}.old"
783 ssh2known_hosts "$host" "$sshKey" >> "$KNOWN_HOSTS"
788 # if at least one key was found...
789 if [ "$nKeys" -gt 0 ] ; then
790 # if ok keys were found, return 0
791 if [ "$nKeysOK" -gt 0 ] ; then
797 # if no keys were found, return 1
803 # update the known_hosts file for a set of hosts listed on command
805 update_known_hosts() {
812 # the number of hosts specified on command line
818 # create a lockfile on known_hosts:
819 lock create "$KNOWN_HOSTS"
820 # FIXME: we're discarding any pre-existing EXIT trap; is this bad?
821 trap "lock remove $KNOWN_HOSTS" EXIT
823 # note pre update file checksum
824 fileCheck="$(file_hash "$KNOWN_HOSTS")"
828 process_host_known_hosts "$host"
832 nHostsOK=$((nHostsOK+1))
835 nHostsBAD=$((nHostsBAD+1))
839 # touch the lockfile, for good measure.
840 lock touch "$KNOWN_HOSTS"
843 # remove the lockfile and the trap
844 lock remove "$KNOWN_HOSTS"
847 # note if the known_hosts file was updated
848 if [ "$(file_hash "$KNOWN_HOSTS")" != "$fileCheck" ] ; then
849 log verbose "known_hosts file updated."
852 # if an acceptable host was found, return 0
853 if [ "$nHostsOK" -gt 0 ] ; then
855 # else if no ok hosts were found...
857 # if no bad host were found then no hosts were found at all,
859 if [ "$nHostsBAD" -eq 0 ] ; then
861 # else if at least one bad host was found, return 2
868 # process hosts from a known_hosts file
869 process_known_hosts() {
872 log verbose "processing known_hosts file..."
874 hosts=$(meat "$KNOWN_HOSTS" | cut -d ' ' -f 1 | grep -v '^|.*$' | tr , ' ' | tr '\n' ' ')
876 if [ -z "$hosts" ] ; then
877 log error "no hosts to process."
881 # take all the hosts from the known_hosts file (first
882 # field), grep out all the hashed hosts (lines starting
884 update_known_hosts $hosts
887 # process uids for the authorized_keys file
888 process_uid_authorized_keys() {
897 log verbose "processing: $userID"
903 for line in $(process_user_id "$userID") ; do
904 # note that key was found
907 ok=$(echo "$line" | cut -d: -f1)
908 sshKey=$(echo "$line" | cut -d: -f2)
910 if [ -z "$sshKey" ] ; then
914 # remove the old host key line
915 remove_line "$AUTHORIZED_KEYS" "$sshKey"
917 # if key OK, add new host line
918 if [ "$ok" -eq '0' ] ; then
919 # note that key was found ok
920 nKeysOK=$((nKeysOK+1))
922 ssh2authorized_keys "$userID" "$sshKey" >> "$AUTHORIZED_KEYS"
926 # if at least one key was found...
927 if [ "$nKeys" -gt 0 ] ; then
928 # if ok keys were found, return 0
929 if [ "$nKeysOK" -gt 0 ] ; then
935 # if no keys were found, return 1
941 # update the authorized_keys files from a list of user IDs on command
943 update_authorized_keys() {
950 # the number of ids specified on command line
956 # create a lockfile on authorized_keys
957 lock create "$AUTHORIZED_KEYS"
958 # FIXME: we're discarding any pre-existing EXIT trap; is this bad?
959 trap "lock remove $AUTHORIZED_KEYS" EXIT
961 # note pre update file checksum
962 fileCheck="$(file_hash "$AUTHORIZED_KEYS")"
964 # remove any monkeysphere lines from authorized_keys file
965 remove_monkeysphere_lines "$AUTHORIZED_KEYS"
968 # process the user ID, change return code if key not found for
970 process_uid_authorized_keys "$userID"
978 nIDsBAD=$((nIDsBAD+1))
982 # touch the lockfile, for good measure.
983 lock touch "$AUTHORIZED_KEYS"
986 # remove the lockfile and the trap
987 lock remove "$AUTHORIZED_KEYS"
990 # note if the authorized_keys file was updated
991 if [ "$(file_hash "$AUTHORIZED_KEYS")" != "$fileCheck" ] ; then
992 log verbose "authorized_keys file updated."
995 # if an acceptable id was found, return 0
996 if [ "$nIDsOK" -gt 0 ] ; then
998 # else if no ok ids were found...
1000 # if no bad ids were found then no ids were found at all, and
1002 if [ "$nIDsBAD" -eq 0 ] ; then
1004 # else if at least one bad id was found, return 2
1011 # process an authorized_user_ids file for authorized_keys
1012 process_authorized_user_ids() {
1017 authorizedUserIDs="$1"
1019 log verbose "processing authorized_user_ids file..."
1021 if ! meat "$authorizedUserIDs" > /dev/null ; then
1022 log error "no user IDs to process."
1028 # extract user IDs from authorized_user_ids file
1030 for line in $(meat "$authorizedUserIDs") ; do
1031 userIDs["$nline"]="$line"
1035 update_authorized_keys "${userIDs[@]}"