3 ### Common key management functions.
5 ### (c) 2011 Mark Wooding
8 ###----- Licensing notice ---------------------------------------------------
10 ### This file is part of the distorted.org.uk key management suite.
12 ### distorted-keys is free software; you can redistribute it and/or modify
13 ### it under the terms of the GNU General Public License as published by
14 ### the Free Software Foundation; either version 2 of the License, or
15 ### (at your option) any later version.
17 ### distorted-keys is distributed in the hope that it will be useful,
18 ### but WITHOUT ANY WARRANTY; without even the implied warranty of
19 ### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 ### GNU General Public License for more details.
22 ### You should have received a copy of the GNU General Public License
23 ### along with distorted-keys; if not, write to the Free Software Foundation,
24 ### Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
28 ###--------------------------------------------------------------------------
29 ### Configuration variables.
31 ## Automatically configured pathnames.
32 PACKAGE="@PACKAGE@" VERSION="@VERSION@"
35 ## Read user configuration.
36 if [ -f $ETC/keys.conf ]; then . $ETC/keys.conf; fi
38 ## Maybe turn on debugging.
39 case "${KEYS_DEBUG+t}" in t) set -x ;; esac
41 ## Fake up caller credentials if not called via userv.
42 case "${USERV_USER+t}" in
44 *) USERV_USER=${LOGNAME-${USER-$(id -un)}} USERV_UID=$(id -u) ;;
46 case "${USERV_GROUP+t}" in
48 *) USERV_GROUP=$(id -Gn) USERV_GID=$(id -gn) ;;
51 ###--------------------------------------------------------------------------
55 cleanup () { cleanups=${cleanups+$cleanups }$1; }
56 runcleanups () { for i in $cleanups; do $i; done; }
57 trap 'rc=$?; runcleanups; exit $rc' EXIT
58 trap 'trap "" EXIT; runcleanups; exit 127' INT TERM
60 ###--------------------------------------------------------------------------
61 ### Utility functions.
64 ## Fail unless a safe directory is set.
66 err="$quis: (CONFIGURATION ERROR)"
69 *) echo >&2 "$err: no SAFE directory"; exit 1 ;;
71 if [ ! -d "$SAFE" ]; then
72 echo >&2 "$err: SAFE path \`$SAFE' isn't a directory"
76 [!/]* | *[][[:space:]*?]*)
77 echo >&2 "$err: SAFE path \`$SAFE' contains bad characters"
83 read perm _ user stuff
87 echo >&2 "$err: SAFE path \`$SAFE' has bad owner or permissions"
94 ## Temporary directory.
96 rmtmp () { case ${tmp+t} in t) cd /; rm -rf $tmp ;; esac; }
99 ## Make a temporary directory and store its name in `tmp'.
101 case "${tmp+t}" in t) return ;; esac
103 tmp="$SAFE/keys.tmp.$$"
109 ## Fail unless a temporary directory is set.
113 *) echo >&2 "$quis (INTERNAL): no tmp directory set"; exit 127 ;;
119 ## Parse the key label string KEY. Set `kdir' to the base path to use for
120 ## the key's storage, and `kowner' to the key owner's name.
123 *:*) kowner=${key%%:*} klabel=${key#*:} ;;
124 *) kowner=$USERV_USER klabel=$key ;;
126 checkword "key owner name" "$kowner"
127 checklabel "key" "$klabel"
128 kdir=$KEYS/store/$kowner/$klabel
129 knub=$KEYS/nub/$kowner/$klabel
132 ###--------------------------------------------------------------------------
133 ### Input validation functions.
138 ckwhat=$1 ckpat=$2 thing=$3
139 ## Verify that THING matches the (anchored, basic) regular expression
140 ## CKPAT. Since matching newlines is hard to do portably, also check that
141 ## THING doesn't contain any. If the checks fail, report an error and
146 *"$nl"*) validp=nil ;;
147 *) if ! expr >/dev/null "$thing" : "$ckpat\$"; then validp=nil; fi ;;
150 nil) echo >&2 "$quis: bad $ckwhat \`$thing'"; exit 1 ;;
154 ## Regular expressions for validating input.
155 R_IDENTCHARS="A-Za-z0-9_"
156 R_WORDCHARS="-$R_IDENTCHARS!%@+="
157 R_IDENT="[$R_IDENTCHARS][$R_IDENTCHARS]*"
158 R_WORD="[$R_WORDCHARS][$R_WORDCHARS]*"
159 R_WORDSEQ="[$R_WORDCHARS[:space:]][$R_WORDCHARS[:space:]]*"
160 R_NUMERIC='\(\([1-9][0-9]*\)\{0,1\}0\{0,1\}\)'
161 R_LABEL="\($R_WORD\(/$R_WORD\)*\)"
164 ## Various validation functions.
165 checknumber () { check "$1" "$R_NUMERIC" "$2"; }
166 checkident () { check "$1" "$R_IDENT" "$2"; }
167 checkword () { check "$1" "$R_WORD" "$2"; }
168 checklabel () { check "$1 label" "$R_LABEL" "$2"; }
170 ###--------------------------------------------------------------------------
171 ### Key storage and properties.
175 ## Write the named system PROFILE to standard output.
177 $bindir/extract-profile "$profile" $ETC/profile.d/
181 what=$1 prefix=$2; shift 2
182 ## Set variables based on the NAME=VALUE assignments in the arguments. The
183 ## value for property NAME is stored in the shell variable PREFIX_NAME.
188 *\=*) name=${assg%%=*} value=${assg#*=} ;;
191 case "$goodp,$name" in t,*[!0-9A-Za-z_]*=*) goodp=nil ;; esac
193 nil) echo >&2 "$quis: bad $what assignment \`$assg'"; exit 1 ;;
195 eval "$prefix$name=\$value"
200 whatprop=$1 prefix=$2; shift 2
201 ## Check that property variables are set in accordance with the remaining
202 ## TABLE arguments. Each row of TABLE has the form
206 ## A table row is satisfied if there is a variable PREFIXNAME whose value
207 ## matces the (basic) regular expression PAT, or if the variable is unset
210 for table in "$@"; do
211 case "$table" in ?*) ;; *) continue ;; esac
212 while read -r name omit pat; do
213 eval foundp=\${$prefix$name+t}
214 case "$foundp,$omit" in
217 echo >&2 "$quis: missing $whatprop \`$name' required"
221 eval value=\$$prefix$name
222 check "value for $whatprop \`$name'" "$pat" "$value"
231 ## Define a properties table NAME.
237 defprops g_props <<EOF
239 recovery t $R_WORDSEQ
243 nub_random_bytes t $R_NUMERIC
248 ## Read a profile from a file. This doesn't check the form of the
249 ## filename, so it's not suitable for unchecked input. Properties are set
250 ## using `setprops' with prefix `kprop_'.
252 ## Parse the settings from the file.
255 case "$line" in "" | \#*) continue ;; esac
256 setprops "property" kprop_ "$line"
259 checkprops "property" kprop_ "$g_props"
261 ## Fetch the key-type handling library.
262 if [ ! -f $KEYSLIB/ktype.$kprop_type ]; then
263 echo >&2 "$quis: unknown key type \`$kprop_type'"
266 . $KEYSLIB/ktype.$kprop_type
267 checkprops "property" kprop_ "$k_props"
272 ## Read key metadata from KDIR.
274 { read profile; } <"$kdir"/meta
278 ## Generate a key nub in the default way, and write it to standard output.
279 ## The properties `random', `nub_random_bytes' and `nub_hash' are referred
283 if=/dev/${kprop_random-random} bs=1 count=${kprop_nub_random_bytes-64} |
284 openssl dgst -${kprop_nub_hash-sha256} -binary |
289 ## Compute a hash of the key nub in stdin, and write it to stdout in hex.
290 ## The property `nubid_hash' is used.
292 { echo "distorted-keys nubid"; cat -; } |
293 openssl dgst -${kprop_nubid_hash-sha256}
297 what=$1 templ=$2 prefix=$3 pat=$4
298 ## Substitute option values into the template TEMPL. Each occurrence of
299 ## %{VAR} is replaced by the value of the variable PREFIXVAR. Finally, an
300 ## error is reported unless the final value matches the regular expression
307 ## If there are no more markers to substitute, then finish.
308 case "$rest" in *"%{"*"}"*) ;; *) out=$out$rest; break ;; esac
310 ## Split the template into three parts.
311 left=${rest%%\%\{*} right=${rest#*\%\{}
312 var=${right%%\}*} rest=${right#*\}}
314 *-*) default=${var#*-} var=${var%%-*} defaultp=t ;;
318 ## Find the variable value.
319 checkident "template variable name" "$var"
320 eval foundp=\${$prefix$var+t}
321 case $foundp,$defaultp in
322 t,*) eval value=\$$prefix$var ;;
323 ,t) value=$default ;;
325 echo >&2 "$quis: option \`$var' unset, used in template \`$templ'"
330 ## Do the substitution.
334 ## Check the final result.
335 check "$what" "$pat" "$out"
343 ## Read property settings from a profile. The PROFILE name has the form
344 ## [USER:]LABEL; USER defaults to OWNER. Properties are set using
345 ## `setprops' with prefix `kprop_'.
350 label=${profile#:} uservp=nil
353 user=$kowner label=$profile uservp=t
356 user=${profile%%:*} label=${profile#*:} uservp=t
359 checkword "profile label" "$label"
361 ## Fetch the profile settings from the user.
365 checkword "profile user" "$user"
366 userv "$user" cryptop-profile "$label" >$tmp/profile
369 $bindir/extract-profile "$label" $ETC/profile.d/ >$tmp/profile
374 readprops $tmp/profile
377 ###--------------------------------------------------------------------------
378 ### General crypto operations.
381 profile=$1 kdir=$2 knub=$3 hook=$4; shift 4
382 ## Generate a key, and associate it with the named PROFILE (which is
383 ## assumed already to have been read!); store the main data in KDIR, and
384 ## the nub separately in the file KNUB; run HOOK after generation, passing
385 ## it the working key directory and nub file. Remaining arguments are
386 ## options to the key type.
388 ## Set options and check them.
389 setprops "option" kopt_ "$@"
390 checkprops "option" kopt_ "$k_genopts"
392 ## Create directory structure and start writing metadata.
394 mkdir -m755 -p "$kdir.new"
395 case "$knub" in */*) mkdir -m700 -p "${knub%/*}" ;; esac
396 cat >"$kdir.new/meta" <<EOF
401 umask=$(umask); umask 077; >"$knub.new"; umask $umask
402 k_generate "$kdir.new" "$knub.new"
403 $hook "$kdir.new" "$knub.new"
406 nubid <"$knub.new" >"$kdir.new/nubid"
408 ## Juggle everything into place. Doing this atomically is very difficult,
409 ## and requires more machinery than I can really justify here. If
410 ## something goes wrong halfway, it should always be possible to fix it,
411 ## either by backing out (if $kdir.new still exists) or pressing on
412 ## forwards (if not).
414 if [ -e "$kdir" ]; then mv "$kdir" "$kdir.old"; fi
415 mv "$kdir.new" "$kdir"
416 mv "$knub.new" "$knub"
420 c_encrypt () { k_encrypt "$@"; }
422 if k_decrypt "$@" >$tmp/plain; then cat $tmp/plain
426 c_sign () { k_sign "$@"; }
427 c_verify () { k_verify "$@"; }
429 ## Stub implementations.
430 notsupp () { op=$1; echo >&2 "$quis: operation \`$op' not supported"; }
432 k_encrypt () { notsupp encrypt; }
433 k_decrypt () { notsupp decrypt; }
434 k_sign () { notsupp sign; }
435 k_verify () { notsupp verify; }
439 ## Prepare for a crypto operation OP, using the KEY. This validates the
440 ## key label, reads the profile, and checks the access-control list. If OP
441 ## is `-' then allow the operation unconditionally.
443 ## Find the key properties.
444 parse_keylabel "$key"
445 if [ ! -d $kdir ]; then echo >&2 "$quis: unknown key \`$key'"; exit 1; fi
447 read_profile $kowner "$profile"
449 ## Check whether we're allowed to do this thing. This is annoyingly
451 case $op in -) return ;; esac
452 eval acl=\${kprop_acl_$op-!owner}
456 ## Remove leading whitespace.
459 [[:space:]]*) acl=${acl#?} ;;
464 ## If there's nothing left, leave.
465 case "$acl" in ?*) ;; *) break ;; esac
467 ## Split off the leading word.
469 *[[:space:]]*) word=${acl%%[[:space:]]*} acl=${acl#*[[:space:]]} ;;
470 *) word=$acl acl="" ;;
473 ## See what sense it has if it matches.
475 -*) sense=forbid rest=${word#-} ;;
476 *) sense=allow rest=$word ;;
479 ## See whether the calling user matches.
481 !owner) pat=$kowner list=$USERV_USER ;;
482 !*) echo >&2 "$quis: unknown ACL token \`$word'" ;;
483 %*) pat=${rest#%} list="$USERV_GROUP $USERV_GID" ;;
484 *) pat=$rest list="$USERV_USER $USERV_UID" ;;
487 for i in $list; do case "$i" in $pat) matchp=t; break ;; esac; done
488 case $matchp in t) verdict=$sense; break ;; esac
492 forbid) echo >&2 "$quis: $op access to key \`$key' forbidden"; exit 1 ;;
496 ###--------------------------------------------------------------------------
497 ### Crypto operations for infrastructure purposes.
501 ## Select the profile in FILE for future crypto operations.
503 unset $(set | sed -n '/^kprop_/s/=.*$//p')
505 getsysprofile "$profile" >$tmp/profile
506 readprops $tmp/profile
510 profile=$1 kdir=$2 knub=$3; shift 3
511 ## Generate a system key using PROFILE; store the data in KDIR and the nub
512 ## in KNUB. Remaining arguments are options.
514 c_sysprofile "$profile"
515 c_genkey "$profile" "$kdir" "$knub" : "$@"
521 c_sysprofile "$profile"
525 op=$1 kdir=$2; shift 1
530 c_sysencrypt () { c_sysop encrypt "$1" /dev/null; }
531 c_sysdecrypt () { c_sysop decrypt "$1" "$2"; }
532 c_syssign () { c_sysop sign "$1" "$2"; }
533 c_sysverify () { c_sysop verify "$1" /dev/null; }
535 ###--------------------------------------------------------------------------
536 ### Recovery operations.
540 ## Stash a copy of stdin encrypted under the recovery key RECOV, with a
542 checkword "recovery key label" "$recov"
543 checklabel "secret" "$label"
545 rdir=$KEYS/recov/$recov/current
546 if [ ! -d $rdir/store ]; then
547 echo >&2 "$quis: unknown recovery key \`$recov'"
550 case $label in */*) mkdir -m755 -p $rdir/${label%/*} ;; esac
551 (c_sysencrypt $rdir/store >$rdir/$label.new)
552 mv $rdir/$label.new $rdir/$label.recov
557 ## Recover a stashed secret, protected by RECOV and stored as LABEL, and
558 ## write it to stdout.
559 checkword "recovery key label" "$recov"
560 checklabel "secret" "$label"
562 rdir=$KEYS/recov/$recov/current
563 if [ ! -f $rdir/$label.recov ]; then
564 echo >&2 "$quis: no blob for \`$label' under recovery key \`$recov'"
568 nub=$SAFE/keys.reveal/$recov.current/nub
569 if [ ! -f $nub ]; then
570 echo >&2 "$quis: current recovery key \`$recov' not revealed"
574 c_sysdecrypt $rdir/store $nub <$rdir/$label.recov
577 ###--------------------------------------------------------------------------
582 usage="usage: $quis${umsg+ }$umsg"
584 case "$KEYS_HELP" in t) help; exit ;; esac
587 help () { showhelp; }
596 usage_err () { echo >&2 "$usage"; exit 1; }
598 ###--------------------------------------------------------------------------
599 ### Subcommand handling.
602 echo "$PACKAGE version $VERSION"
615 -h Show this help text.
616 -v Show the program version number.
621 for i in $prefix.*; do
622 if [ ! -x "$i" ]; then continue; fi
623 sed -n "/<<HELP/{n;s/^/ ${i#$prefix.} /;p;q;}" "$i"
629 if [ ! -x "$KEYSLIB/$prefix.$i" ]; then
630 echo >&2 "$quis: unrecognized command \`$i'"
633 elif ! KEYS_HELP=t "$KEYSLIB/$prefix.$i"; then
643 case $# in 0) echo >&2 "$usage"; exit 1 ;; esac
645 case "$cmd" in help) cmd_help "$@"; exit ;; esac
646 if [ ! -x "$KEYSLIB/$prefix.$cmd" ]; then
647 echo >&2 "$quis: unrecognized command \`$cmd'"
652 exec "$KEYSLIB/$prefix.$cmd" "$@"
655 ###----- That's all, folks --------------------------------------------------