aae5598877dd90272cea7a87a32ff2928e1d1cfb
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 case ":$PATH:" in *:"$bindir":*) ;; *) PATH
=$bindir:$PATH ;; esac
36 if [ -f
$ETC/keys.conf
]; then .
$ETC/keys.conf
; fi
38 case "${KEYS_DEBUG+t}" in t
) set -x
;; esac
40 ###--------------------------------------------------------------------------
44 cleanup
() { cleanups
=${cleanups+$cleanups }$1; }
45 runcleanups
() { for i
in $cleanups; do $i; done; }
46 trap 'rc=$?; runcleanups; exit $rc' EXIT
47 trap 'trap "" EXIT; runcleanups; exit 127' INT TERM
49 ###--------------------------------------------------------------------------
50 ### Utility functions.
53 ## Fail unless a safe directory is set.
55 err
="$quis: (CONFIGURATION ERROR)"
58 *) echo >&2 "$err: no SAFE directory"; exit 1 ;;
60 if [ ! -d
"$SAFE" ]; then
61 echo >&2 "$err: SAFE path \`$SAFE' isn't a directory"
65 [!/]* |
*[][[:space
:]*?
]*)
66 echo >&2 "$err: SAFE path \`$SAFE' contains bad characters"
72 read perm _ user stuff
76 echo >&2 "$err: SAFE path \`$SAFE' has bad owner or permissions"
83 ## Temporary directory.
85 rmtmp
() { case ${tmp+t} in t
) cd /; rm -rf
$tmp ;; esac; }
88 ## Make a temporary directory and store its name in `tmp'.
90 case "${tmp+t}" in t
) return ;; esac
92 tmp
="$SAFE/keys.tmp.$$"
98 ## Fail unless a temporary directory is set.
102 *) echo >&2 "$quis (INTERNAL): no tmp directory set"; exit 127 ;;
108 ## Parse the key label string KEY. Set `kdir' to the base path to use for
109 ## the key's storage, and `kowner' to the key owner's name.
112 *:*) kowner
=${key%%:*} klabel
=${key#*:} ;;
113 *) kowner
=$USERV_USER klabel
=$key ;;
115 checkword
"key owner name" "$kowner"
116 checklabel
"key" "$klabel"
117 kdir
=$KEYS/store
/$kowner/$klabel
118 knub
=$KEYS/nub
/$kowner/$klabel
121 ###--------------------------------------------------------------------------
122 ### Input validation functions.
127 ckwhat
=$1 ckpat
=$2 thing
=$3
128 ## Verify that THING matches the (anchored, basic) regular expression
129 ## CKPAT. Since matching newlines is hard to do portably, also check that
130 ## THING doesn't contain any. If the checks fail, report an error and
135 *"$nl"*) validp
=nil
;;
136 *) if ! expr >/dev
/null
"$thing" : "$ckpat\$"; then validp
=nil
; fi ;;
139 nil
) echo >&2 "$quis: bad $ckwhat \`$thing'"; exit 1 ;;
143 ## Regular expressions for validating input.
144 R_IDENTCHARS
="A-Za-z0-9_"
145 R_WORDCHARS
="-$R_IDENTCHARS!%@+="
146 R_IDENT
="[$R_IDENTCHARS][$R_IDENTCHARS]*"
147 R_WORD
="[$R_WORDCHARS][$R_WORDCHARS]*"
148 R_WORDSEQ
="[$R_WORDCHARS[:space:]][$R_WORDCHARS[:space:]]*"
149 R_NUMERIC
='\(\([1-9][0-9]*\)\{0,1\}0\{0,1\}\)'
150 R_LABEL
="\($R_WORD\(/$R_WORD\)*\)"
153 ## Various validation functions.
154 checknumber
() { check
"$1" "$R_NUMERIC" "$2"; }
155 checkident
() { check
"$1" "$R_IDENT" "$2"; }
156 checkword
() { check
"$1" "$R_WORD" "$2"; }
157 checklabel
() { check
"$1 label" "$R_LABEL" "$2"; }
159 ###--------------------------------------------------------------------------
160 ### Key storage and properties.
164 ## Write the named system PROFILE to standard output.
166 $bindir/extract-profile
"$profile" $ETC/profile.d
/
170 what
=$1 prefix
=$2; shift 2
171 ## Set variables based on the NAME=VALUE assignments in the arguments. The
172 ## value for property NAME is stored in the shell variable PREFIX_NAME.
177 *\
=*) name
=${assg%%=*} value
=${assg#*=} ;;
180 case "$goodp,$name" in t
,*[!0-9A-Za-z_
]*=*) goodp
=nil
;; esac
182 nil
) echo >&2 "$quis: bad $what assignment \`$assg'"; exit 1 ;;
184 eval "$prefix$name=\$value"
189 whatprop
=$1 prefix
=$2; shift 2
190 ## Check that property variables are set in accordance with the remaining
191 ## TABLE arguments. Each row of TABLE has the form
195 ## A table row is satisfied if there is a variable PREFIXNAME whose value
196 ## matces the (basic) regular expression PAT, or if the variable is unset
199 for table
in "$@"; do
200 case "$table" in ?
*) ;; *) continue ;; esac
201 while read -r name omit pat
; do
202 eval foundp
=\
${$prefix$name+t}
203 case "$foundp,$omit" in
206 echo >&2 "$quis: missing $whatprop \`$name' required"
210 eval value
=\$
$prefix$name
211 check
"value for $whatprop \`$name'" "$pat" "$value"
220 ## Define a properties table NAME.
226 defprops g_props
<<EOF
228 recovery t $R_WORDSEQ
237 ## Read a profile from a file. This doesn't check the form of the
238 ## filename, so it's not suitable for unchecked input. Properties are set
239 ## using `setprops' with prefix `kprop_'.
241 ## Parse the settings from the file.
244 case "$line" in "" | \
#*) continue ;; esac
245 setprops
"property" kprop_
"$line"
248 checkprops
"property" kprop_
"$g_props"
250 ## Fetch the key-type handling library.
251 if [ ! -f
$KEYSLIB/ktype.
$kprop_type ]; then
252 echo >&2 "$quis: unknown key type \`$kprop_type'"
255 .
$KEYSLIB/ktype.
$kprop_type
256 checkprops
"property" kprop_
"$k_props"
261 ## Read key metadata from KDIR.
263 { read profile
; } <"$kdir"/meta
267 ## Generate a key nub in the default way, and write it to standard output.
268 ## The properties `random', `nubsz' and `nubhash' are referred to.
271 if=/dev
/${kprop_random-random} bs
=1 count
=${kprop_nubsz-512} |
272 openssl dgst
-${kprop_nubhash-sha384} -binary |
277 ## Compute a hash of the key nub in stdin, and write it to stdout in hex.
278 ## The property `nubidhash' is used.
280 { echo "distorted-keys nubid"; cat -; } |
281 openssl dgst
-${kprop_nubidhash-sha256}
285 what
=$1 templ
=$2 prefix
=$3 pat
=$4
286 ## Substitute option values into the template TEMPL. Each occurrence of
287 ## %{VAR} is replaced by the value of the variable PREFIXVAR. Finally, an
288 ## error is reported unless the final value matches the regular expression
295 ## If there are no more markers to substitute, then finish.
296 case "$rest" in *"%{"*"}"*) ;; *) out
=$out$rest; break ;; esac
298 ## Split the template into three parts.
299 left
=${rest%%\%\{*} right
=${rest#*\%\{}
300 var
=${right%%\}*} rest
=${right#*\}}
302 *-*) default
=${var#*-} var
=${var%%-*} defaultp
=t
;;
306 ## Find the variable value.
307 checkident
"template variable name" "$var"
308 eval foundp
=\
${$prefix$var+t}
309 case $foundp,$defaultp in
310 t
,*) eval value
=\$
$prefix$var ;;
311 ,t
) value
=$default ;;
313 echo >&2 "$quis: option \`$var' unset, used in template \`$templ'"
318 ## Do the substitution.
322 ## Check the final result.
323 check
"$what" "$pat" "$out"
331 ## Read property settings from a profile. The PROFILE name has the form
332 ## [USER:]LABEL. Properties are set using `setprops' with prefix `kprop_'.
337 label
=${profile#:} uservp
=nil
340 user
=$USERV_USER label
=$profile uservp
=t
343 user
=${profile%%:*} label
=${profile#*:} uservp
=t
346 checkword
"profile label" "$label"
348 ## Fetch the profile settings from the user.
352 checkword
"profile user" "$user"
353 userv
"$user" cryptop-profile
"$label" >$tmp/profile
356 $bindir/extract-profile
"$label" $ETC/profile.d
/ >$tmp/profile
361 readprops
$tmp/profile
364 ###--------------------------------------------------------------------------
365 ### General crypto operations.
368 profile
=$1 kdir
=$2 knub
=$3 hook
=$4; shift 4
369 ## Generate a key, and associate it with the named PROFILE (which is
370 ## assumed already to have been read!); store the main data in KDIR, and
371 ## the nub separately in the file KNUB; run HOOK after generation, passing
372 ## it the working key directory and nub file. Remaining arguments are
373 ## options to the key type.
375 ## Set options and check them.
376 setprops
"option" kopt_
"$@"
377 checkprops
"option" kopt_
"$k_genopts"
379 ## Create directory structure and start writing metadata.
381 mkdir
-m755
-p
"$kdir.new"
382 case "$knub" in */*) mkdir
-m700
-p
"${knub%/*}" ;; esac
383 cat >"$kdir.new/meta" <<EOF
388 umask=$
(umask); umask 077; >"$knub.new"; umask $umask
389 k_generate
"$kdir.new" "$knub.new"
390 $hook "$kdir.new" "$knub.new"
393 nubid
<"$knub.new" >"$kdir.new/nubid"
395 ## Juggle everything into place. Doing this atomically is very difficult,
396 ## and requires more machinery than I can really justify here. If
397 ## something goes wrong halfway, it should always be possible to fix it,
398 ## either by backing out (if $kdir.new still exists) or pressing on
399 ## forwards (if not).
401 if [ -e
"$kdir" ]; then mv "$kdir" "$kdir.old"; fi
402 mv "$kdir.new" "$kdir"
403 mv "$knub.new" "$knub"
407 c_encrypt
() { k_encrypt
"$@"; }
409 if k_decrypt
"$@" >$tmp/plain
; then cat $tmp/plain
413 c_sign
() { k_sign
"$@"; }
414 c_verify
() { k_verify
"$@"; }
416 ## Stub implementations.
417 notsupp
() { op
=$1; echo >&2 "$quis: operation \`$op' not supported"; }
419 k_encrypt
() { notsupp encrypt
; }
420 k_decrypt
() { notsupp decrypt
; }
421 k_sign
() { notsupp sign
; }
422 k_verify
() { notsupp verify
; }
426 ## Prepare for a crypto operation OP, using the KEY. This validates the
427 ## key label, reads the profile, and checks the access-control list.
429 ## Find the key properties.
430 parse_keylabel
"$key"
431 if [ ! -d
$kdir ]; then echo >&2 "$quis: unknown key \`$key'"; exit 1; fi
433 read_profile
"$profile"
435 ## Check whether we're allowed to do this thing. This is annoyingly
437 eval acl
=\
${kprop_acl_$op-!owner}
441 ## Remove leading whitespace.
444 [[:space
:]]*) acl
=${acl#?} ;;
449 ## If there's nothing left, leave.
450 case "$acl" in ?
*) ;; *) break ;; esac
452 ## Split off the leading word.
454 *[[:space
:]]*) word
=${acl%%[[:space:]]*} acl
=${acl#*[[:space:]]} ;;
455 *) word
=$acl acl
="" ;;
458 ## See what sense it has if it matches.
460 -*) sense
=forbid rest
=${word#-} ;;
461 *) sense
=allow rest
=$word ;;
464 ## See whether the calling user matches.
466 !owner
) pat
=$kowner list
=$USERV_USER ;;
467 !*) echo >&2 "$quis: unknown ACL token \`$word'" ;;
468 %*) pat
=${rest#%} list
="$USERV_GROUP $USERV_GID" ;;
469 *) pat
=$rest list
="$USERV_USER $USERV_UID" ;;
472 for i
in $list; do case "$i" in $pat) matchp
=t
; break ;; esac; done
473 case $matchp in t
) verdict
=$sense; break ;; esac
477 forbid
) echo >&2 "$quis: $op access to key \`$key' forbidden"; exit ;;
481 ###--------------------------------------------------------------------------
482 ### Crypto operations for infrastructure purposes.
486 ## Select the profile in FILE for future crypto operations.
488 unset $
(set |
sed -n
'/^kprop_/s/=.*$//p')
490 getsysprofile
"$profile" >$tmp/profile
491 readprops
$tmp/profile
495 profile
=$1 kdir
=$2 knub
=$3; shift 3
496 ## Generate a system key using PROFILE; store the data in KDIR and the nub
497 ## in KNUB. Remaining arguments are options.
499 c_sysprofile
"$profile"
500 c_genkey
"$profile" "$kdir" "$knub" : "$@"
506 c_sysprofile
"$profile"
510 op
=$1 kdir
=$2; shift 1
515 c_sysencrypt
() { c_sysop encrypt
"$1" /dev
/null
; }
516 c_sysdecrypt
() { c_sysop decrypt
"$1" "$2"; }
517 c_syssign
() { c_sysop sign
"$1" "$2"; }
518 c_sysverify
() { c_sysop verify
"$1" /dev
/null
; }
520 ###--------------------------------------------------------------------------
521 ### Recovery operations.
525 ## Stash a copy of stdin encrypted under the recovery key RECOV, with a
527 checkword
"recovery key label" "$recov"
528 checklabel
"secret" "$label"
530 rdir
=$KEYS/recov
/$recov/current
531 if [ ! -d
$rdir/store
]; then
532 echo >&2 "$quis: unknown recovery key \`$recov'"
535 case $label in */*) mkdir
-m755
-p
$rdir/${label%/*} ;; esac
536 (c_sysencrypt
$rdir/store
>$rdir/$label.new
)
537 mv $rdir/$label.new
$rdir/$label.recov
542 ## Recover a stashed secret, protected by RECOV and stored as LABEL, and
543 ## write it to stdout.
544 checkword
"recovery key label" "$recov"
545 checklabel
"secret" "$label"
547 rdir
=$KEYS/recov
/$recov/current
548 if [ ! -f
$rdir/$label.recov
]; then
549 echo >&2 "$quis: no blob for \`$label' under recovery key \`$recov'"
553 nub
=$SAFE/keys.reveal
/$recov.current
/nub
554 if [ ! -f
$nub ]; then
555 echo >&2 "$quis: current recovery key \`$recov' not revealed"
559 c_sysdecrypt
$rdir/store
$nub <$rdir/$label.recov
562 ###--------------------------------------------------------------------------
567 usage
="usage: $quis${umsg+ }$umsg"
569 case "$KEYS_HELP" in t
) help; exit ;; esac
572 help () { showhelp
; }
581 usage_err
() { echo >&2 "$usage"; exit 1; }
583 ###--------------------------------------------------------------------------
584 ### Subcommand handling.
587 echo "$PACKAGE version $VERSION"
600 -h Show this help text.
601 -v Show the program version number.
606 for i
in $prefix.
*; do
607 if [ ! -x
"$i" ]; then continue; fi
608 sed -n
"/<<HELP/{n;s/^/ ${i#$prefix.} /;p;q;}" "$i"
614 if [ ! -x
"$KEYSLIB/$prefix.$i" ]; then
615 echo >&2 "$quis: unrecognized command \`$i'"
618 elif ! KEYS_HELP
=t
"$KEYSLIB/$prefix.$i"; then
628 case $# in 0) echo >&2 "$usage"; exit 1 ;; esac
630 case "$cmd" in help) cmd_help
"$@"; exit ;; esac
631 if [ ! -x
"$KEYSLIB/$prefix.$cmd" ]; then
632 echo >&2 "$quis: unrecognized command \`$cmd'"
637 exec "$KEYSLIB/$prefix.$cmd" "$@"
640 ###----- That's all, folks --------------------------------------------------