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
133 user=$1 service=$2; shift 2
134 ## If the current (effective) user is not USER then reinvoke via `userv',
135 ## as the specified service, with the remaining arguments.
139 *) exec userv "$user" "$service" "$@" ;;
143 ###--------------------------------------------------------------------------
144 ### Input validation functions.
149 ckwhat=$1 ckpat=$2 thing=$3
150 ## Verify that THING matches the (anchored, basic) regular expression
151 ## CKPAT. Since matching newlines is hard to do portably, also check that
152 ## THING doesn't contain any. If the checks fail, report an error and
157 *"$nl"*) validp=nil ;;
158 *) if ! expr >/dev/null "Q$thing" : "Q$ckpat\$"; then validp=nil; fi ;;
161 nil) echo >&2 "$quis: bad $ckwhat \`$thing'"; exit 1 ;;
165 ## Regular expressions for validating input.
166 R_IDENTCHARS="A-Za-z0-9_"
168 R_WORDCHARS="-$R_IDENTCHARS$R_GOODPUNCT"
169 R_IDENT="[$R_IDENTCHARS][$R_IDENTCHARS]*"
170 R_WORD="[$R_WORDCHARS][$R_WORDCHARS]*"
171 R_ACLCHARS="][$R_IDENTCHARS$R_GOODPUNCT*?:.#"
172 R_WORDSEQ="[$R_WORDCHARS[:space:]][$R_WORDCHARS[:space:]]*"
173 R_ACL="[$R_ACLCHARS[:space:]-][$R_ACLCHARS[:space:]-]*"
174 R_NUMERIC='\(\([1-9][0-9]*\)\{0,1\}0\{0,1\}\)'
175 R_LABEL="\($R_WORD\(/$R_WORD\)*\)"
178 ## Various validation functions.
179 checknumber () { check "$1" "$R_NUMERIC" "$2"; }
180 checkident () { check "$1" "$R_IDENT" "$2"; }
181 checkword () { check "$1" "$R_WORD" "$2"; }
182 checklabel () { check "$1 label" "$R_LABEL" "$2"; }
184 ###--------------------------------------------------------------------------
185 ### Key storage and properties.
189 ## Write the named system PROFILE to standard output.
191 $bindir/extract-profile "$profile" $ETC/profile.d/
195 what=$1 prefix=$2; shift 2
196 ## Set variables based on the NAME=VALUE assignments in the arguments. The
197 ## value for property NAME is stored in the shell variable PREFIX_NAME.
202 *\=*) name=${assg%%=*} value=${assg#*=} ;;
205 case "$goodp,$name" in t,*[!0-9A-Za-z_]*=*) goodp=nil ;; esac
207 nil) echo >&2 "$quis: bad $what assignment \`$assg'"; exit 1 ;;
209 eval "$prefix$name=\$value"
214 whatprop=$1 prefix=$2; shift 2
215 ## Check that property variables are set in accordance with the remaining
216 ## TABLE arguments. Each row of TABLE has the form
220 ## A table row is satisfied if there is a variable PREFIXNAME whose value
221 ## matces the (basic) regular expression PAT, or if the variable is unset
224 for table in "$@"; do
225 case "$table" in ?*) ;; *) continue ;; esac
226 while read -r name omit pat; do
227 eval foundp=\${$prefix$name+t}
228 case "$foundp,$omit" in
231 echo >&2 "$quis: missing $whatprop \`$name' required"
235 eval value=\$$prefix$name
236 check "value for $whatprop \`$name'" "$pat" "$value"
245 ## Write the properties stored in the variables beginning with PREFIX.
247 set | sed -n "/^$prefix/{s/=.*\$//;p}" | sort | while read name; do
249 echo "${name#$prefix}=$value"
255 ## Define a properties table NAME.
261 defprops g_props <<EOF
263 recovery t $R_WORDSEQ
267 nub_random_bytes t $R_NUMERIC
277 ## Read a profile from a file. This doesn't check the form of the
278 ## filename, so it's not suitable for unchecked input. Properties are set
279 ## using `setprops' with prefix `kprop_'.
281 ## Parse the settings from the file.
284 case "$line" in "" | \#*) continue ;; esac
285 setprops "property" kprop_ "$line"
288 checkprops "property" kprop_ "$g_props"
290 ## Fetch the key-type handling library.
291 if [ ! -f $KEYSLIB/ktype.$kprop_type ]; then
292 echo >&2 "$quis: unknown key type \`$kprop_type'"
295 . $KEYSLIB/ktype.$kprop_type
296 checkprops "property" kprop_ "$k_props"
301 ## Read key metadata from KDIR.
303 { read profile; } <"$kdir"/meta
307 ## Generate a key nub in the default way, and write it to standard output.
308 ## The properties `random', `nub_random_bytes' and `nub_hash' are referred
312 if=/dev/${kprop_random-random} bs=1 count=${kprop_nub_random_bytes-64} |
313 openssl dgst -${kprop_nub_hash-sha256} -binary |
318 ## Compute a hash of the key nub in stdin, and write it to stdout in hex.
319 ## The property `nubid_hash' is used.
321 ## Stupid dance because the output incompatibly grew a filename, in order
322 ## to demonstrate the same idiocy as GNU mumblesum.
323 set _ $({ echo "distorted-keys nubid"; cat -; } |
324 openssl dgst -${kprop_nubid_hash-sha256})
325 if [ $# -gt 2 ]; then shift; fi
330 what=$1 templ=$2 prefix=$3 pat=$4
331 ## Substitute option values into the template TEMPL. Each occurrence of
332 ## %{VAR} is replaced by the value of the variable PREFIXVAR. Finally, an
333 ## error is reported unless the final value matches the regular expression
340 ## If there are no more markers to substitute, then finish.
341 case "$rest" in *"%{"*"}"*) ;; *) out=$out$rest; break ;; esac
343 ## Split the template into three parts.
344 left=${rest%%\%\{*} right=${rest#*\%\{}
345 var=${right%%\}*} rest=${right#*\}}
347 *-*) default=${var#*-} var=${var%%-*} defaultp=t ;;
351 ## Find the variable value.
352 checkident "template variable name" "$var"
353 eval foundp=\${$prefix$var+t}
354 case $foundp,$defaultp in
355 t,*) eval value=\$$prefix$var ;;
356 ,t) value=$default ;;
358 echo >&2 "$quis: option \`$var' unset, used in template \`$templ'"
363 ## Do the substitution.
367 ## Check the final result.
368 check "$what" "$pat" "$out"
376 ## Read property settings from a profile. The PROFILE name has the form
377 ## [USER:]LABEL; USER defaults to OWNER. Properties are set using
378 ## `setprops' with prefix `kprop_'.
383 label=${profile#:} uservp=nil
386 user=$kowner label=$profile uservp=t
389 user=${profile%%:*} label=${profile#*:} uservp=t
392 checkword "profile label" "$label"
394 ## Fetch the profile settings from the user.
398 checkword "profile user" "$user"
399 userv "$user" cryptop-profile "$label" >$tmp/profile </dev/null
402 $bindir/extract-profile "$label" $ETC/profile.d/ >$tmp/profile
407 readprops $tmp/profile
410 ###--------------------------------------------------------------------------
411 ### General crypto operations.
414 profile=$1 kdir=$2 knub=$3 hook=$4; shift 4
415 ## Generate a key, and associate it with the named PROFILE (which is
416 ## assumed already to have been read!); store the main data in KDIR, and
417 ## the nub separately in the file KNUB; run HOOK after generation, passing
418 ## it the working key directory and nub file. Remaining arguments are
419 ## options to the key type.
421 ## Set options and check them.
422 setprops "option" kopt_ "$@"
423 checkprops "option" kopt_ "$k_genopts"
425 ## Create directory structure and start writing metadata.
427 mkdir -m755 -p "$kdir.new"
428 case "$knub" in */*) mkdir -m700 -p "${knub%/*}" ;; esac
429 cat >"$kdir.new/meta" <<EOF
434 umask=$(umask); umask 077; >"$knub.new"; umask $umask
435 k_generate "$kdir.new" "$knub.new"
436 $hook "$kdir.new" "$knub.new"
439 nubid <"$knub.new" >"$kdir.new/nubid"
441 ## Juggle everything into place. Doing this atomically is very difficult,
442 ## and requires more machinery than I can really justify here. If
443 ## something goes wrong halfway, it should always be possible to fix it,
444 ## either by backing out (if $kdir.new still exists) or pressing on
445 ## forwards (if not).
447 if [ -e "$kdir" ]; then mv "$kdir" "$kdir.old"; fi
448 mv "$kdir.new" "$kdir"
449 mv "$knub.new" "$knub"
453 c_encrypt () { k_encrypt "$@"; }
455 if k_decrypt "$@" >$tmp/plain; then cat $tmp/plain
459 c_sign () { k_sign "$@"; }
460 c_verify () { k_verify "$@"; }
462 ## Stub implementations.
463 notsupp () { op=$1; echo >&2 "$quis: operation \`$op' not supported"; }
466 k_encrypt () { notsupp encrypt; }
467 k_decrypt () { notsupp decrypt; }
468 k_sign () { notsupp sign; }
469 k_verify () { notsupp verify; }
473 ## Prepare for a crypto operation OP, using the KEY. This validates the
474 ## key label, reads the profile, and checks the access-control list. If OP
475 ## is `-' then allow the operation unconditionally.
477 ## Find the key properties.
478 parse_keylabel "$key"
479 if [ ! -d $kdir ]; then echo >&2 "$quis: unknown key \`$key'"; exit 1; fi
481 read_profile $kowner "$profile"
483 ## Check whether we're allowed to do this thing. This is annoyingly
485 case $op in -) return ;; esac
486 eval acl=\${kprop_acl_$op-!owner}
490 ## Remove leading whitespace.
493 [[:space:]]*) acl=${acl#?} ;;
498 ## If there's nothing left, leave.
499 case "$acl" in ?*) ;; *) break ;; esac
501 ## Split off the leading word.
503 *[[:space:]]*) word=${acl%%[[:space:]]*} acl=${acl#*[[:space:]]} ;;
504 *) word=$acl acl="" ;;
507 ## See what sense it has if it matches.
509 -*) sense=forbid rest=${word#-} ;;
510 *) sense=allow rest=$word ;;
513 ## See whether the calling user matches.
515 !owner) pat=$kowner list=$USERV_USER ;;
516 !*) echo >&2 "$quis: unknown ACL token \`$word'" ;;
517 %*) pat=${rest#%} list="$USERV_GROUP $USERV_GID" ;;
518 *) pat=$rest list="$USERV_USER $USERV_UID" ;;
521 for i in $list; do case "$i" in $pat) matchp=t; break ;; esac; done
522 case $matchp in t) verdict=$sense; break ;; esac
526 forbid) echo >&2 "$quis: $op access to key \`$key' forbidden"; exit 1 ;;
530 ###--------------------------------------------------------------------------
531 ### Crypto operations for infrastructure purposes.
535 ## Select the profile in FILE for future crypto operations.
537 unset $(set | sed -n '/^kprop_/s/=.*$//p')
539 getsysprofile "$profile" >$tmp/profile
540 readprops $tmp/profile
544 profile=$1 kdir=$2 knub=$3; shift 3
545 ## Generate a system key using PROFILE; store the data in KDIR and the nub
546 ## in KNUB. Remaining arguments are options.
548 c_sysprofile "$profile"
549 c_genkey "$profile" "$kdir" "$knub" : "$@"
555 c_sysprofile "$profile"
559 op=$1 kdir=$2; shift 1
564 c_sysencrypt () { c_sysop encrypt "$1" /dev/null; }
565 c_sysdecrypt () { c_sysop decrypt "$1" "$2"; }
566 c_syssign () { c_sysop sign "$1" "$2"; }
567 c_sysverify () { c_sysop verify "$1" /dev/null; }
569 ###--------------------------------------------------------------------------
570 ### Recovery operations.
574 ## Return the sharing threshold from the parameter file PARAM.
580 echo >&2 "$quis: secret sharing parameter file damaged (wrong header)"
588 echo >&2 "$quis: secret sharing parameter file damaged (missing t)"
599 ## Stash a copy of stdin encrypted under the recovery key RECOV, with a
601 checkword "recovery key label" "$recov"
602 checklabel "secret" "$label"
604 rdir=$KEYS/recov/$recov/current
605 if [ ! -d $rdir/store ]; then
606 echo >&2 "$quis: unknown recovery key \`$recov'"
609 case $label in */*) mkdir -m755 -p $rdir/${label%/*} ;; esac
610 (c_sysencrypt $rdir/store >$rdir/$label.new)
611 mv $rdir/$label.new $rdir/$label.recov
616 ## Recover a stashed secret, protected by RECOV and stored as LABEL, and
617 ## write it to stdout.
618 checkword "recovery key label" "$recov"
619 checklabel "secret" "$label"
621 rdir=$KEYS/recov/$recov/current
622 if [ ! -f $rdir/$label.recov ]; then
623 echo >&2 "$quis: no blob for \`$label' under recovery key \`$recov'"
627 nub=$SAFE/keys.reveal/$recov.current/nub
628 if [ ! -f $nub ]; then
629 echo >&2 "$quis: current recovery key \`$recov' not revealed"
633 c_sysdecrypt $rdir/store $nub <$rdir/$label.recov
636 ###--------------------------------------------------------------------------
643 case "$KEYS_HELP" in t) help; exit ;; esac
646 help () { showhelp; }
649 Usage: $quis${usage:+ $usage}
657 echo "usage: $quis${cmdname:+ $cmdname}${cmdargs:+ $cmdargs}"
659 usage_err () { usage >&2; exit 1; }
661 ###--------------------------------------------------------------------------
662 ### Subcommand handling.
665 echo "$PACKAGE version $VERSION"
672 cmd=$1; shift; args=$*
674 eval help_$cmd=\$help
679 defcmd help "[COMMAND ...]" <<EOF
680 Show help about the COMMANDs, or about $quis if none are named.
689 Usage: $quis${usage:+ $usage}
692 -h Show this help text.
693 -v Show the program version number.
697 while read cmd args; do echo " $cmd${args:+ $args}"; done <<EOF
703 for i in $prefix.*; do
704 if [ ! -x "$i" ]; then continue; fi
705 sed -n "/<<HELP/{n;s/^/ ${i#$prefix.} /;p;q;}" "$i"
714 while read cmdname cmdargs; do
715 case $cmdname in "$cmd") foundp=t; break ;; esac
721 eval help=\$help_$cmdname; echo "$help"
724 if [ ! -x "$KEYSLIB/$prefix.$cmd" ]; then
725 echo >&2 "$quis: unrecognized command \`$cmd'"
728 elif ! KEYS_HELP=t "$KEYSLIB/$prefix.$cmd"; then
740 case $# in 0) usage_err ;; esac
743 while read cmdname cmdargs; do
744 case $cmdname in "$cmd") foundp=t; break ;; esac
754 if [ ! -x "$KEYSLIB/$prefix.$cmd" ]; then
755 echo >&2 "$quis: unrecognized command \`$cmd'"
759 exec "$KEYSLIB/$prefix.$cmd" "$@"
764 ###----- That's all, folks --------------------------------------------------