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 ###--------------------------------------------------------------------------
45 cleanup
() { cleanups
=${cleanups+$cleanups }$1; }
46 runcleanups
() { for i
in $cleanups; do $i; done; }
47 trap 'rc=$?; runcleanups; exit $rc' EXIT
48 trap 'trap "" EXIT; runcleanups; exit 127' INT TERM
50 ###--------------------------------------------------------------------------
51 ### Utility functions.
54 ## Fail unless a safe directory is set.
56 err
="$quis: (CONFIGURATION ERROR)"
59 *) echo >&2 "$err: no SAFE directory"; exit 1 ;;
61 if [ ! -d
"$SAFE" ]; then
62 echo >&2 "$err: SAFE path \`$SAFE' isn't a directory"
66 [!/]* |
*[][[:space
:]*?
]*)
67 echo >&2 "$err: SAFE path \`$SAFE' contains bad characters"
73 read perm _ user stuff
77 echo >&2 "$err: SAFE path \`$SAFE' has bad owner or permissions"
84 ## Temporary directory.
86 rmtmp
() { case ${tmp+t} in t
) cd /; rm -rf
$tmp ;; esac; }
89 ## Make a temporary directory and store its name in `tmp'.
91 case "${tmp+t}" in t
) return ;; esac
93 tmp
="$SAFE/keys.tmp.$$"
99 ## Fail unless a temporary directory is set.
103 *) echo >&2 "$quis (INTERNAL): no tmp directory set"; exit 127 ;;
109 ## Parse the key label string KEY. Set `kdir' to the base path to use for
110 ## the key's storage, and `kowner' to the key owner's name.
113 *:*) kowner
=${key%%:*} klabel
=${key#*:} ;;
114 *) kowner
=$USERV_USER klabel
=$key ;;
116 checkword
"key owner name" "$kowner"
117 checklabel
"key" "$klabel"
118 kdir
=$KEYS/store
/$kowner/$klabel
119 knub
=$KEYS/nub
/$kowner/$klabel
122 ###--------------------------------------------------------------------------
123 ### Input validation functions.
128 ckwhat
=$1 ckpat
=$2 thing
=$3
129 ## Verify that THING matches the (anchored, basic) regular expression
130 ## CKPAT. Since matching newlines is hard to do portably, also check that
131 ## THING doesn't contain any. If the checks fail, report an error and
136 *"$nl"*) validp
=nil
;;
137 *) if ! expr >/dev
/null
"$thing" : "$ckpat\$"; then validp
=nil
; fi ;;
140 nil
) echo >&2 "$quis: bad $ckwhat \`$thing'"; exit 1 ;;
144 ## Regular expressions for validating input.
145 R_IDENTCHARS
="A-Za-z0-9_"
146 R_WORDCHARS
="-$R_IDENTCHARS!%@+="
147 R_IDENT
="[$R_IDENTCHARS][$R_IDENTCHARS]*"
148 R_WORD
="[$R_WORDCHARS][$R_WORDCHARS]*"
149 R_WORDSEQ
="[$R_WORDCHARS[:space:]][$R_WORDCHARS[:space:]]*"
150 R_NUMERIC
='\(\([1-9][0-9]*\)\{0,1\}0\{0,1\}\)'
151 R_LABEL
="\($R_WORD\(/$R_WORD\)*\)"
154 ## Various validation functions.
155 checknumber
() { check
"$1" "$R_NUMERIC" "$2"; }
156 checkident
() { check
"$1" "$R_IDENT" "$2"; }
157 checkword
() { check
"$1" "$R_WORD" "$2"; }
158 checklabel
() { check
"$1 label" "$R_LABEL" "$2"; }
160 ###--------------------------------------------------------------------------
161 ### Key storage and properties.
165 ## Write the named system PROFILE to standard output.
167 $bindir/extract-profile
"$profile" $ETC/profile.d
/
171 what
=$1 prefix
=$2; shift 2
172 ## Set variables based on the NAME=VALUE assignments in the arguments. The
173 ## value for property NAME is stored in the shell variable PREFIX_NAME.
178 *\
=*) name
=${assg%%=*} value
=${assg#*=} ;;
181 case "$goodp,$name" in t
,*[!0-9A-Za-z_
]*=*) goodp
=nil
;; esac
183 nil
) echo >&2 "$quis: bad $what assignment \`$assg'"; exit 1 ;;
185 eval "$prefix$name=\$value"
190 whatprop
=$1 prefix
=$2; shift 2
191 ## Check that property variables are set in accordance with the remaining
192 ## TABLE arguments. Each row of TABLE has the form
196 ## A table row is satisfied if there is a variable PREFIXNAME whose value
197 ## matces the (basic) regular expression PAT, or if the variable is unset
200 for table
in "$@"; do
201 case "$table" in ?
*) ;; *) continue ;; esac
202 while read -r name omit pat
; do
203 eval foundp
=\
${$prefix$name+t}
204 case "$foundp,$omit" in
207 echo >&2 "$quis: missing $whatprop \`$name' required"
211 eval value
=\$
$prefix$name
212 check
"value for $whatprop \`$name'" "$pat" "$value"
221 ## Define a properties table NAME.
227 defprops g_props
<<EOF
229 recovery t $R_WORDSEQ
233 nub_random_bytes t $R_NUMERIC
238 ## Read a profile from a file. This doesn't check the form of the
239 ## filename, so it's not suitable for unchecked input. Properties are set
240 ## using `setprops' with prefix `kprop_'.
242 ## Parse the settings from the file.
245 case "$line" in "" | \
#*) continue ;; esac
246 setprops
"property" kprop_
"$line"
249 checkprops
"property" kprop_
"$g_props"
251 ## Fetch the key-type handling library.
252 if [ ! -f
$KEYSLIB/ktype.
$kprop_type ]; then
253 echo >&2 "$quis: unknown key type \`$kprop_type'"
256 .
$KEYSLIB/ktype.
$kprop_type
257 checkprops
"property" kprop_
"$k_props"
262 ## Read key metadata from KDIR.
264 { read profile
; } <"$kdir"/meta
268 ## Generate a key nub in the default way, and write it to standard output.
269 ## The properties `random', `nub_random_bytes' and `nub_hash' are referred
273 if=/dev
/${kprop_random-random} bs
=1 count
=${kprop_nub_random_bytes-64} |
274 openssl dgst
-${kprop_nub_hash-sha256} -binary |
279 ## Compute a hash of the key nub in stdin, and write it to stdout in hex.
280 ## The property `nubid_hash' is used.
282 { echo "distorted-keys nubid"; cat -; } |
283 openssl dgst
-${kprop_nubid_hash-sha256}
287 what
=$1 templ
=$2 prefix
=$3 pat
=$4
288 ## Substitute option values into the template TEMPL. Each occurrence of
289 ## %{VAR} is replaced by the value of the variable PREFIXVAR. Finally, an
290 ## error is reported unless the final value matches the regular expression
297 ## If there are no more markers to substitute, then finish.
298 case "$rest" in *"%{"*"}"*) ;; *) out
=$out$rest; break ;; esac
300 ## Split the template into three parts.
301 left
=${rest%%\%\{*} right
=${rest#*\%\{}
302 var
=${right%%\}*} rest
=${right#*\}}
304 *-*) default
=${var#*-} var
=${var%%-*} defaultp
=t
;;
308 ## Find the variable value.
309 checkident
"template variable name" "$var"
310 eval foundp
=\
${$prefix$var+t}
311 case $foundp,$defaultp in
312 t
,*) eval value
=\$
$prefix$var ;;
313 ,t
) value
=$default ;;
315 echo >&2 "$quis: option \`$var' unset, used in template \`$templ'"
320 ## Do the substitution.
324 ## Check the final result.
325 check
"$what" "$pat" "$out"
333 ## Read property settings from a profile. The PROFILE name has the form
334 ## [USER:]LABEL. Properties are set using `setprops' with prefix `kprop_'.
339 label
=${profile#:} uservp
=nil
342 user
=$USERV_USER label
=$profile uservp
=t
345 user
=${profile%%:*} label
=${profile#*:} uservp
=t
348 checkword
"profile label" "$label"
350 ## Fetch the profile settings from the user.
354 checkword
"profile user" "$user"
355 userv
"$user" cryptop-profile
"$label" >$tmp/profile
358 $bindir/extract-profile
"$label" $ETC/profile.d
/ >$tmp/profile
363 readprops
$tmp/profile
366 ###--------------------------------------------------------------------------
367 ### General crypto operations.
370 profile
=$1 kdir
=$2 knub
=$3 hook
=$4; shift 4
371 ## Generate a key, and associate it with the named PROFILE (which is
372 ## assumed already to have been read!); store the main data in KDIR, and
373 ## the nub separately in the file KNUB; run HOOK after generation, passing
374 ## it the working key directory and nub file. Remaining arguments are
375 ## options to the key type.
377 ## Set options and check them.
378 setprops
"option" kopt_
"$@"
379 checkprops
"option" kopt_
"$k_genopts"
381 ## Create directory structure and start writing metadata.
383 mkdir
-m755
-p
"$kdir.new"
384 case "$knub" in */*) mkdir
-m700
-p
"${knub%/*}" ;; esac
385 cat >"$kdir.new/meta" <<EOF
390 umask=$
(umask); umask 077; >"$knub.new"; umask $umask
391 k_generate
"$kdir.new" "$knub.new"
392 $hook "$kdir.new" "$knub.new"
395 nubid
<"$knub.new" >"$kdir.new/nubid"
397 ## Juggle everything into place. Doing this atomically is very difficult,
398 ## and requires more machinery than I can really justify here. If
399 ## something goes wrong halfway, it should always be possible to fix it,
400 ## either by backing out (if $kdir.new still exists) or pressing on
401 ## forwards (if not).
403 if [ -e
"$kdir" ]; then mv "$kdir" "$kdir.old"; fi
404 mv "$kdir.new" "$kdir"
405 mv "$knub.new" "$knub"
409 c_encrypt
() { k_encrypt
"$@"; }
411 if k_decrypt
"$@" >$tmp/plain
; then cat $tmp/plain
415 c_sign
() { k_sign
"$@"; }
416 c_verify
() { k_verify
"$@"; }
418 ## Stub implementations.
419 notsupp
() { op
=$1; echo >&2 "$quis: operation \`$op' not supported"; }
421 k_encrypt
() { notsupp encrypt
; }
422 k_decrypt
() { notsupp decrypt
; }
423 k_sign
() { notsupp sign
; }
424 k_verify
() { notsupp verify
; }
428 ## Prepare for a crypto operation OP, using the KEY. This validates the
429 ## key label, reads the profile, and checks the access-control list. If OP
430 ## is `-' then allow the operation unconditionally.
432 ## Find the key properties.
433 parse_keylabel
"$key"
434 if [ ! -d
$kdir ]; then echo >&2 "$quis: unknown key \`$key'"; exit 1; fi
436 read_profile
"$profile"
438 ## Check whether we're allowed to do this thing. This is annoyingly
440 case $op in -) return ;; esac
441 eval acl
=\
${kprop_acl_$op-!owner}
445 ## Remove leading whitespace.
448 [[:space
:]]*) acl
=${acl#?} ;;
453 ## If there's nothing left, leave.
454 case "$acl" in ?
*) ;; *) break ;; esac
456 ## Split off the leading word.
458 *[[:space
:]]*) word
=${acl%%[[:space:]]*} acl
=${acl#*[[:space:]]} ;;
459 *) word
=$acl acl
="" ;;
462 ## See what sense it has if it matches.
464 -*) sense
=forbid rest
=${word#-} ;;
465 *) sense
=allow rest
=$word ;;
468 ## See whether the calling user matches.
470 !owner
) pat
=$kowner list
=$USERV_USER ;;
471 !*) echo >&2 "$quis: unknown ACL token \`$word'" ;;
472 %*) pat
=${rest#%} list
="$USERV_GROUP $USERV_GID" ;;
473 *) pat
=$rest list
="$USERV_USER $USERV_UID" ;;
476 for i
in $list; do case "$i" in $pat) matchp
=t
; break ;; esac; done
477 case $matchp in t
) verdict
=$sense; break ;; esac
481 forbid
) echo >&2 "$quis: $op access to key \`$key' forbidden"; exit 1 ;;
485 ###--------------------------------------------------------------------------
486 ### Crypto operations for infrastructure purposes.
490 ## Select the profile in FILE for future crypto operations.
492 unset $
(set |
sed -n
'/^kprop_/s/=.*$//p')
494 getsysprofile
"$profile" >$tmp/profile
495 readprops
$tmp/profile
499 profile
=$1 kdir
=$2 knub
=$3; shift 3
500 ## Generate a system key using PROFILE; store the data in KDIR and the nub
501 ## in KNUB. Remaining arguments are options.
503 c_sysprofile
"$profile"
504 c_genkey
"$profile" "$kdir" "$knub" : "$@"
510 c_sysprofile
"$profile"
514 op
=$1 kdir
=$2; shift 1
519 c_sysencrypt
() { c_sysop encrypt
"$1" /dev
/null
; }
520 c_sysdecrypt
() { c_sysop decrypt
"$1" "$2"; }
521 c_syssign
() { c_sysop sign
"$1" "$2"; }
522 c_sysverify
() { c_sysop verify
"$1" /dev
/null
; }
524 ###--------------------------------------------------------------------------
525 ### Recovery operations.
529 ## Stash a copy of stdin encrypted under the recovery key RECOV, with a
531 checkword
"recovery key label" "$recov"
532 checklabel
"secret" "$label"
534 rdir
=$KEYS/recov
/$recov/current
535 if [ ! -d
$rdir/store
]; then
536 echo >&2 "$quis: unknown recovery key \`$recov'"
539 case $label in */*) mkdir
-m755
-p
$rdir/${label%/*} ;; esac
540 (c_sysencrypt
$rdir/store
>$rdir/$label.new
)
541 mv $rdir/$label.new
$rdir/$label.recov
546 ## Recover a stashed secret, protected by RECOV and stored as LABEL, and
547 ## write it to stdout.
548 checkword
"recovery key label" "$recov"
549 checklabel
"secret" "$label"
551 rdir
=$KEYS/recov
/$recov/current
552 if [ ! -f
$rdir/$label.recov
]; then
553 echo >&2 "$quis: no blob for \`$label' under recovery key \`$recov'"
557 nub
=$SAFE/keys.reveal
/$recov.current
/nub
558 if [ ! -f
$nub ]; then
559 echo >&2 "$quis: current recovery key \`$recov' not revealed"
563 c_sysdecrypt
$rdir/store
$nub <$rdir/$label.recov
566 ###--------------------------------------------------------------------------
571 usage
="usage: $quis${umsg+ }$umsg"
573 case "$KEYS_HELP" in t
) help; exit ;; esac
576 help () { showhelp
; }
585 usage_err
() { echo >&2 "$usage"; exit 1; }
587 ###--------------------------------------------------------------------------
588 ### Subcommand handling.
591 echo "$PACKAGE version $VERSION"
604 -h Show this help text.
605 -v Show the program version number.
610 for i
in $prefix.
*; do
611 if [ ! -x
"$i" ]; then continue; fi
612 sed -n
"/<<HELP/{n;s/^/ ${i#$prefix.} /;p;q;}" "$i"
618 if [ ! -x
"$KEYSLIB/$prefix.$i" ]; then
619 echo >&2 "$quis: unrecognized command \`$i'"
622 elif ! KEYS_HELP
=t
"$KEYSLIB/$prefix.$i"; then
632 case $# in 0) echo >&2 "$usage"; exit 1 ;; esac
634 case "$cmd" in help) cmd_help
"$@"; exit ;; esac
635 if [ ! -x
"$KEYSLIB/$prefix.$cmd" ]; then
636 echo >&2 "$quis: unrecognized command \`$cmd'"
641 exec "$KEYSLIB/$prefix.$cmd" "$@"
644 ###----- That's all, folks --------------------------------------------------