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 PACKAGE="@PACKAGE@" VERSION="@VERSION@"
34 if [ -f $ETC/keys.conf ]; then . $ETC/keys.conf; fi
36 case "${KEYS_DEBUG+t}" in t) set -x ;; esac
38 ###--------------------------------------------------------------------------
42 cleanup () { cleanups=${cleanups+$cleanups }$1; }
43 runcleanups () { for i in $cleanups; do $i; done; }
44 trap 'rc=$?; runcleanups; exit $rc' EXIT
45 trap 'trap "" EXIT; runcleanups; exit 127' INT TERM
47 ###--------------------------------------------------------------------------
48 ### Utility functions.
51 ## Fail unless a safe directory is set.
53 err="$quis: (CONFIGURATION ERROR)"
56 *) echo >&2 "$err: no SAFE directory"; exit 1 ;;
58 if [ ! -d "$SAFE" ]; then
59 echo >&2 "$err: SAFE path \`$SAFE' isn't a directory"
63 [!/]* | *[][[:space:]*?]*)
64 echo >&2 "$err: SAFE path \`$SAFE' contains bad characters"
70 read perm _ user stuff
74 echo >&2 "$err: SAFE path \`$SAFE' has bad owner or permissions"
81 ## Temporary directory.
83 rmtmp () { case ${tmp+t} in t) cd /; rm -rf $tmp ;; esac; }
86 ## Make a temporary directory and store its name in `tmp'.
88 case "${tmp+t}" in t) return ;; esac
90 tmp="$SAFE/keys.tmp.$$"
96 ## Fail unless a temporary directory is set.
100 *) echo >&2 "$quis (INTERNAL): no tmp directory set"; exit 127 ;;
106 ## Parse the key label string KEY. Set `kdir' to the base path to use for
107 ## the key's storage, and `kowner' to the key owner's name.
110 *:*) kowner=${key%%:*} klabel=${key#*:} ;;
111 *) kowner=$USERV_USER klabel=$key ;;
113 checkword "key owner name" "$kowner"
114 checklabel "key" "$klabel"
115 kdir=$KEYS/store/$kowner/$klabel
116 knub=$KEYS/nub/$kowner/$klabel
119 ###--------------------------------------------------------------------------
120 ### Input validation functions.
125 ckwhat=$1 ckpat=$2 thing=$3
126 ## Verify that THING matches the (anchored, basic) regular expression
127 ## CKPAT. Since matching newlines is hard to do portably, also check that
128 ## THING doesn't contain any. If the checks fail, report an error and
133 *"$nl"*) validp=nil ;;
134 *) if ! expr >/dev/null "$thing" : "$ckpat\$"; then validp=nil; fi ;;
137 nil) echo >&2 "$quis: bad $ckwhat \`$thing'"; exit 1 ;;
141 ## Regular expressions for validating input.
142 R_IDENTCHARS="A-Za-z0-9_"
143 R_WORDCHARS="-$R_IDENTCHARS!%@+="
144 R_IDENT="[$R_IDENTCHARS][$R_IDENTCHARS]*"
145 R_WORD="[$R_WORDCHARS][$R_WORDCHARS]*"
146 R_WORDSEQ="[$R_WORDCHARS[:space:]][$R_WORDCHARS[:space:]]*"
147 R_NUMERIC='\(\([1-9][0-9]*\)\{0,1\}0\{0,1\}\)'
148 R_LABEL="\($R_WORD\(/$R_WORD\)*\)"
151 ## Various validation functions.
152 checknumber () { check "$1" "$R_NUMERIC" "$2"; }
153 checkident () { check "$1" "$R_IDENT" "$2"; }
154 checkword () { check "$1" "$R_WORD" "$2"; }
155 checklabel () { check "$1 label" "$R_LABEL" "$2"; }
157 ###--------------------------------------------------------------------------
158 ### Key storage and properties.
162 ## Write the named system PROFILE to standard output.
164 $bindir/extract-profile "$profile" $ETC/profile.d/
168 what=$1 prefix=$2; shift 2
169 ## Set variables based on the NAME=VALUE assignments in the arguments. The
170 ## value for property NAME is stored in the shell variable PREFIX_NAME.
175 *\=*) name=${assg%%=*} value=${assg#*=} ;;
178 case "$goodp,$name" in t,*[!0-9A-Za-z_]*=*) goodp=nil ;; esac
180 nil) echo >&2 "$quis: bad $what assignment \`$assg'"; exit 1 ;;
182 eval "$prefix$name=\$value"
187 whatprop=$1 prefix=$2; shift 2
188 ## Check that property variables are set in accordance with the remaining
189 ## TABLE arguments. Each row of TABLE has the form
193 ## A table row is satisfied if there is a variable PREFIXNAME whose value
194 ## matces the (basic) regular expression PAT, or if the variable is unset
197 for table in "$@"; do
198 case "$table" in ?*) ;; *) continue ;; esac
199 while read -r name omit pat; do
200 eval foundp=\${$prefix$name+t}
201 case "$foundp,$omit" in
204 echo >&2 "$quis: missing $whatprop \`$name' required"
208 eval value=\$$prefix$name
209 check "value for $whatprop \`$name'" "$pat" "$value"
218 ## Define a properties table NAME.
224 defprops g_props <<EOF
226 recovery t $R_WORDSEQ
230 nub_random_bytes t $R_NUMERIC
235 ## Read a profile from a file. This doesn't check the form of the
236 ## filename, so it's not suitable for unchecked input. Properties are set
237 ## using `setprops' with prefix `kprop_'.
239 ## Parse the settings from the file.
242 case "$line" in "" | \#*) continue ;; esac
243 setprops "property" kprop_ "$line"
246 checkprops "property" kprop_ "$g_props"
248 ## Fetch the key-type handling library.
249 if [ ! -f $KEYSLIB/ktype.$kprop_type ]; then
250 echo >&2 "$quis: unknown key type \`$kprop_type'"
253 . $KEYSLIB/ktype.$kprop_type
254 checkprops "property" kprop_ "$k_props"
259 ## Read key metadata from KDIR.
261 { read profile; } <"$kdir"/meta
265 ## Generate a key nub in the default way, and write it to standard output.
266 ## The properties `random', `nub_random_bytes' and `nub_hash' are referred
270 if=/dev/${kprop_random-random} bs=1 count=${kprop_nub_random_bytes-64} |
271 openssl dgst -${kprop_nub_hash-sha256} -binary |
276 ## Compute a hash of the key nub in stdin, and write it to stdout in hex.
277 ## The property `nubid_hash' is used.
279 { echo "distorted-keys nubid"; cat -; } |
280 openssl dgst -${kprop_nubid_hash-sha256}
284 what=$1 templ=$2 prefix=$3 pat=$4
285 ## Substitute option values into the template TEMPL. Each occurrence of
286 ## %{VAR} is replaced by the value of the variable PREFIXVAR. Finally, an
287 ## error is reported unless the final value matches the regular expression
294 ## If there are no more markers to substitute, then finish.
295 case "$rest" in *"%{"*"}"*) ;; *) out=$out$rest; break ;; esac
297 ## Split the template into three parts.
298 left=${rest%%\%\{*} right=${rest#*\%\{}
299 var=${right%%\}*} rest=${right#*\}}
301 *-*) default=${var#*-} var=${var%%-*} defaultp=t ;;
305 ## Find the variable value.
306 checkident "template variable name" "$var"
307 eval foundp=\${$prefix$var+t}
308 case $foundp,$defaultp in
309 t,*) eval value=\$$prefix$var ;;
310 ,t) value=$default ;;
312 echo >&2 "$quis: option \`$var' unset, used in template \`$templ'"
317 ## Do the substitution.
321 ## Check the final result.
322 check "$what" "$pat" "$out"
330 ## Read property settings from a profile. The PROFILE name has the form
331 ## [USER:]LABEL. Properties are set using `setprops' with prefix `kprop_'.
336 label=${profile#:} uservp=nil
339 user=$USERV_USER label=$profile uservp=t
342 user=${profile%%:*} label=${profile#*:} uservp=t
345 checkword "profile label" "$label"
347 ## Fetch the profile settings from the user.
351 checkword "profile user" "$user"
352 userv "$user" cryptop-profile "$label" >$tmp/profile
355 $bindir/extract-profile "$label" $ETC/profile.d/ >$tmp/profile
360 readprops $tmp/profile
363 ###--------------------------------------------------------------------------
364 ### General crypto operations.
367 profile=$1 kdir=$2 knub=$3 hook=$4; shift 4
368 ## Generate a key, and associate it with the named PROFILE (which is
369 ## assumed already to have been read!); store the main data in KDIR, and
370 ## the nub separately in the file KNUB; run HOOK after generation, passing
371 ## it the working key directory and nub file. Remaining arguments are
372 ## options to the key type.
374 ## Set options and check them.
375 setprops "option" kopt_ "$@"
376 checkprops "option" kopt_ "$k_genopts"
378 ## Create directory structure and start writing metadata.
380 mkdir -m755 -p "$kdir.new"
381 case "$knub" in */*) mkdir -m700 -p "${knub%/*}" ;; esac
382 cat >"$kdir.new/meta" <<EOF
387 umask=$(umask); umask 077; >"$knub.new"; umask $umask
388 k_generate "$kdir.new" "$knub.new"
389 $hook "$kdir.new" "$knub.new"
392 nubid <"$knub.new" >"$kdir.new/nubid"
394 ## Juggle everything into place. Doing this atomically is very difficult,
395 ## and requires more machinery than I can really justify here. If
396 ## something goes wrong halfway, it should always be possible to fix it,
397 ## either by backing out (if $kdir.new still exists) or pressing on
398 ## forwards (if not).
400 if [ -e "$kdir" ]; then mv "$kdir" "$kdir.old"; fi
401 mv "$kdir.new" "$kdir"
402 mv "$knub.new" "$knub"
406 c_encrypt () { k_encrypt "$@"; }
408 if k_decrypt "$@" >$tmp/plain; then cat $tmp/plain
412 c_sign () { k_sign "$@"; }
413 c_verify () { k_verify "$@"; }
415 ## Stub implementations.
416 notsupp () { op=$1; echo >&2 "$quis: operation \`$op' not supported"; }
418 k_encrypt () { notsupp encrypt; }
419 k_decrypt () { notsupp decrypt; }
420 k_sign () { notsupp sign; }
421 k_verify () { notsupp verify; }
425 ## Prepare for a crypto operation OP, using the KEY. This validates the
426 ## key label, reads the profile, and checks the access-control list.
428 ## Find the key properties.
429 parse_keylabel "$key"
430 if [ ! -d $kdir ]; then echo >&2 "$quis: unknown key \`$key'"; exit 1; fi
432 read_profile "$profile"
434 ## Check whether we're allowed to do this thing. This is annoyingly
436 eval acl=\${kprop_acl_$op-!owner}
440 ## Remove leading whitespace.
443 [[:space:]]*) acl=${acl#?} ;;
448 ## If there's nothing left, leave.
449 case "$acl" in ?*) ;; *) break ;; esac
451 ## Split off the leading word.
453 *[[:space:]]*) word=${acl%%[[:space:]]*} acl=${acl#*[[:space:]]} ;;
454 *) word=$acl acl="" ;;
457 ## See what sense it has if it matches.
459 -*) sense=forbid rest=${word#-} ;;
460 *) sense=allow rest=$word ;;
463 ## See whether the calling user matches.
465 !owner) pat=$kowner list=$USERV_USER ;;
466 !*) echo >&2 "$quis: unknown ACL token \`$word'" ;;
467 %*) pat=${rest#%} list="$USERV_GROUP $USERV_GID" ;;
468 *) pat=$rest list="$USERV_USER $USERV_UID" ;;
471 for i in $list; do case "$i" in $pat) matchp=t; break ;; esac; done
472 case $matchp in t) verdict=$sense; break ;; esac
476 forbid) echo >&2 "$quis: $op access to key \`$key' forbidden"; exit 1 ;;
480 ###--------------------------------------------------------------------------
481 ### Crypto operations for infrastructure purposes.
485 ## Select the profile in FILE for future crypto operations.
487 unset $(set | sed -n '/^kprop_/s/=.*$//p')
489 getsysprofile "$profile" >$tmp/profile
490 readprops $tmp/profile
494 profile=$1 kdir=$2 knub=$3; shift 3
495 ## Generate a system key using PROFILE; store the data in KDIR and the nub
496 ## in KNUB. Remaining arguments are options.
498 c_sysprofile "$profile"
499 c_genkey "$profile" "$kdir" "$knub" : "$@"
505 c_sysprofile "$profile"
509 op=$1 kdir=$2; shift 1
514 c_sysencrypt () { c_sysop encrypt "$1" /dev/null; }
515 c_sysdecrypt () { c_sysop decrypt "$1" "$2"; }
516 c_syssign () { c_sysop sign "$1" "$2"; }
517 c_sysverify () { c_sysop verify "$1" /dev/null; }
519 ###--------------------------------------------------------------------------
520 ### Recovery operations.
524 ## Stash a copy of stdin encrypted under the recovery key RECOV, with a
526 checkword "recovery key label" "$recov"
527 checklabel "secret" "$label"
529 rdir=$KEYS/recov/$recov/current
530 if [ ! -d $rdir/store ]; then
531 echo >&2 "$quis: unknown recovery key \`$recov'"
534 case $label in */*) mkdir -m755 -p $rdir/${label%/*} ;; esac
535 (c_sysencrypt $rdir/store >$rdir/$label.new)
536 mv $rdir/$label.new $rdir/$label.recov
541 ## Recover a stashed secret, protected by RECOV and stored as LABEL, and
542 ## write it to stdout.
543 checkword "recovery key label" "$recov"
544 checklabel "secret" "$label"
546 rdir=$KEYS/recov/$recov/current
547 if [ ! -f $rdir/$label.recov ]; then
548 echo >&2 "$quis: no blob for \`$label' under recovery key \`$recov'"
552 nub=$SAFE/keys.reveal/$recov.current/nub
553 if [ ! -f $nub ]; then
554 echo >&2 "$quis: current recovery key \`$recov' not revealed"
558 c_sysdecrypt $rdir/store $nub <$rdir/$label.recov
561 ###--------------------------------------------------------------------------
566 usage="usage: $quis${umsg+ }$umsg"
568 case "$KEYS_HELP" in t) help; exit ;; esac
571 help () { showhelp; }
580 usage_err () { echo >&2 "$usage"; exit 1; }
582 ###--------------------------------------------------------------------------
583 ### Subcommand handling.
586 echo "$PACKAGE version $VERSION"
599 -h Show this help text.
600 -v Show the program version number.
605 for i in $prefix.*; do
606 if [ ! -x "$i" ]; then continue; fi
607 sed -n "/<<HELP/{n;s/^/ ${i#$prefix.} /;p;q;}" "$i"
613 if [ ! -x "$KEYSLIB/$prefix.$i" ]; then
614 echo >&2 "$quis: unrecognized command \`$i'"
617 elif ! KEYS_HELP=t "$KEYSLIB/$prefix.$i"; then
627 case $# in 0) echo >&2 "$usage"; exit 1 ;; esac
629 case "$cmd" in help) cmd_help "$@"; exit ;; esac
630 if [ ! -x "$KEYSLIB/$prefix.$cmd" ]; then
631 echo >&2 "$quis: unrecognized command \`$cmd'"
636 exec "$KEYSLIB/$prefix.$cmd" "$@"
639 ###----- That's all, folks --------------------------------------------------