X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/distorted-keys/blobdiff_plain/68023101ab409d775673edadb77079a7adf50374..865fc4a1c4add30fbf1b6ab9569682d82e8da7c9:/keyfunc.sh.in?ds=sidebyside

diff --git a/keyfunc.sh.in b/keyfunc.sh.in
index 82ed9e5..6cba169 100644
--- a/keyfunc.sh.in
+++ b/keyfunc.sh.in
@@ -28,15 +28,26 @@ quis=${0##*/}
 ###--------------------------------------------------------------------------
 ### Configuration variables.
 
+## Automatically configured pathnames.
 PACKAGE="@PACKAGE@" VERSION="@VERSION@"
 bindir="@bindir@"
 
-case ":$PATH:" in *:"$bindir":*) ;; *) PATH=$bindir:$PATH ;; esac
-
+## Read user configuration.
 if [ -f $ETC/keys.conf ]; then . $ETC/keys.conf; fi
 
+## Maybe turn on debugging.
 case "${KEYS_DEBUG+t}" in t) set -x ;; esac
 
+## Fake up caller credentials if not called via userv.
+case "${USERV_USER+t}" in
+  t) ;;
+  *) USERV_USER=${LOGNAME-${USER-$(id -un)}} USERV_UID=$(id -u) ;;
+esac
+case "${USERV_GROUP+t}" in
+  t) ;;
+  *) USERV_GROUP=$(id -Gn) USERV_GID=$(id -gn) ;;
+esac
+
 ###--------------------------------------------------------------------------
 ### Cleanup handling.
 
@@ -118,6 +129,17 @@ parse_keylabel () {
   knub=$KEYS/nub/$kowner/$klabel
 }
 
+runas () {
+  user=$1 service=$2; shift 2
+  ## If the current (effective) user is not USER then reinvoke via `userv',
+  ## as the specified service, with the remaining arguments.
+
+  case $(id -un) in
+    "$user") ;;
+    *) exec userv "$user" "$service" "$@" ;;
+  esac
+}
+
 ###--------------------------------------------------------------------------
 ### Input validation functions.
 
@@ -133,7 +155,7 @@ check () {
   validp=t
   case "$thing" in
     *"$nl"*) validp=nil ;;
-    *) if ! expr >/dev/null "$thing" : "$ckpat\$"; then validp=nil; fi ;;
+    *) if ! expr >/dev/null "Q$thing" : "Q$ckpat\$"; then validp=nil; fi ;;
   esac
   case $validp in
     nil) echo >&2 "$quis: bad $ckwhat \`$thing'"; exit 1 ;;
@@ -142,10 +164,13 @@ check () {
 
 ## Regular expressions for validating input.
 R_IDENTCHARS="A-Za-z0-9_"
-R_WORDCHARS="-$R_IDENTCHARS!%@+="
+R_GOODPUNCT="!%@+="
+R_WORDCHARS="-$R_IDENTCHARS$R_GOODPUNCT"
 R_IDENT="[$R_IDENTCHARS][$R_IDENTCHARS]*"
 R_WORD="[$R_WORDCHARS][$R_WORDCHARS]*"
+R_ACLCHARS="][$R_IDENTCHARS$R_GOODPUNCT*?:.#"
 R_WORDSEQ="[$R_WORDCHARS[:space:]][$R_WORDCHARS[:space:]]*"
+R_ACL="[$R_ACLCHARS[:space:]-][$R_ACLCHARS[:space:]-]*"
 R_NUMERIC='\(\([1-9][0-9]*\)\{0,1\}0\{0,1\}\)'
 R_LABEL="\($R_WORD\(/$R_WORD\)*\)"
 R_LINE=".*"
@@ -215,6 +240,16 @@ EOF
   done
 }
 
+dumpprops () {
+  prefix=$1
+  ## Write the properties stored in the variables beginning with PREFIX.
+
+  set | sed -n "/^$prefix/{s/=.*\$//;p}" | sort | while read name; do
+    eval value=\$$name
+    echo "${name#$prefix}=$value"
+  done
+}
+
 defprops () {
   name=$1
   ## Define a properties table NAME.
@@ -227,9 +262,14 @@ defprops g_props <<EOF
 type			nil	$R_IDENT
 recovery		t	$R_WORDSEQ
 random			t	$R_WORD
-nubhash			t	$R_WORD
-nubidhash		t	$R_WORD
-nubsz			t	$R_NUMERIC
+nub_hash		t	$R_WORD
+nubid_hash		t	$R_WORD
+nub_random_bytes	t	$R_NUMERIC
+acl_encrypt		t	$R_ACL
+acl_decrypt		t	$R_ACL
+acl_sign		t	$R_ACL
+acl_verify		t	$R_ACL
+acl_info		t	$R_ACL
 EOF
 
 readprops () {
@@ -265,20 +305,25 @@ readmeta () {
 
 makenub () {
   ## Generate a key nub in the default way, and write it to standard output.
-  ## The properties `random', `nubsz' and `nubhash' are referred to.
+  ## The properties `random', `nub_random_bytes' and `nub_hash' are referred
+  ## to.
 
   dd 2>/dev/null \
-    if=/dev/${kprop_random-random} bs=1 count=${kprop_nubsz-512} |
-  openssl dgst -${kprop_nubhash-sha384} -binary |
+    if=/dev/${kprop_random-random} bs=1 count=${kprop_nub_random_bytes-64} |
+  openssl dgst -${kprop_nub_hash-sha256} -binary |
   openssl base64
 }
 
 nubid () {
   ## Compute a hash of the key nub in stdin, and write it to stdout in hex.
-  ## The property `nubidhash' is used.
-
-  { echo "distorted-keys nubid"; cat -; } |
-  openssl dgst -${kprop_nubidhash-sha256}
+  ## The property `nubid_hash' is used.
+
+  ## Stupid dance because the output incompatibly grew a filename, in order
+  ## to demonstrate the same idiocy as GNU mumblesum.
+  set _ $({ echo "distorted-keys nubid"; cat -; } |
+    openssl dgst -${kprop_nubid_hash-sha256})
+  if [ $# -gt 2 ]; then shift; fi
+  echo $2
 }
 
 subst () {
@@ -327,9 +372,10 @@ subst () {
 }
 
 read_profile () {
-  profile=$1
+  owner=$1 profile=$2
   ## Read property settings from a profile.  The PROFILE name has the form
-  ## [USER:]LABEL.  Properties are set using `setprops' with prefix `kprop_'.
+  ## [USER:]LABEL; USER defaults to OWNER.  Properties are set using
+  ## `setprops' with prefix `kprop_'.
 
   reqtmp
   case "$profile" in
@@ -337,7 +383,7 @@ read_profile () {
       label=${profile#:} uservp=nil
       ;;
     *)
-      user=$USERV_USER label=$profile uservp=t
+      user=$kowner label=$profile uservp=t
       ;;
     *:*)
       user=${profile%%:*} label=${profile#*:} uservp=t
@@ -350,7 +396,7 @@ read_profile () {
   case $uservp in
     t)
       checkword "profile user" "$user"
-      userv "$user" cryptop-profile "$label" >$tmp/profile
+      userv "$user" cryptop-profile "$label" >$tmp/profile </dev/null
       ;;
     nil)
       $bindir/extract-profile "$label" $ETC/profile.d/ >$tmp/profile
@@ -416,6 +462,7 @@ c_verify () { k_verify "$@"; }
 ## Stub implementations.
 notsupp () { op=$1; echo >&2 "$quis: operation \`$op' not supported"; }
 k_info () { :; }
+k_import () { :; }
 k_encrypt () { notsupp encrypt; }
 k_decrypt () { notsupp decrypt; }
 k_sign () { notsupp sign; }
@@ -424,16 +471,18 @@ k_verify () { notsupp verify; }
 prepare () {
   key=$1 op=$2
   ## Prepare for a crypto operation OP, using the KEY.  This validates the
-  ## key label, reads the profile, and checks the access-control list.
+  ## key label, reads the profile, and checks the access-control list.  If OP
+  ## is `-' then allow the operation unconditionally.
 
   ## Find the key properties.
   parse_keylabel "$key"
   if [ ! -d $kdir ]; then echo >&2 "$quis: unknown key \`$key'"; exit 1; fi
   readmeta $kdir
-  read_profile "$profile"
+  read_profile $kowner "$profile"
 
   ## Check whether we're allowed to do this thing.  This is annoyingly
   ## fiddly.
+  case $op in -) return ;; esac
   eval acl=\${kprop_acl_$op-!owner}
   verdict=forbid
   while :; do
@@ -520,6 +569,31 @@ c_sysverify () { c_sysop verify "$1" /dev/null; }
 ###--------------------------------------------------------------------------
 ### Recovery operations.
 
+sharethresh () {
+  pf=$1
+  ## Return the sharing threshold from the parameter file PARAM.
+
+  read param <"$pf"
+  case "$param" in
+    shamir-params:*) ;;
+    *)
+      echo >&2 "$quis: secret sharing parameter file damaged (wrong header)"
+      exit 1
+      ;;
+  esac
+  t=";${param#*:}"
+  case "$t" in
+    *";t="*) ;;
+    *)
+      echo >&2 "$quis: secret sharing parameter file damaged (missing t)"
+      exit 1
+      ;;
+  esac
+  t=${t#*;t=}
+  t=${t%%;*}
+  echo "$t"
+}
+
 stash () {
   recov=$1 label=$2
   ## Stash a copy of stdin encrypted under the recovery key RECOV, with a
@@ -538,21 +612,23 @@ stash () {
 }
 
 recover () {
-  recov=$1 label=$2
+  recov=$1 inst=$2 label=$3
   ## Recover a stashed secret, protected by RECOV and stored as LABEL, and
   ## write it to stdout.
   checkword "recovery key label" "$recov"
+  checkword "recovery instance" "$inst"
   checklabel "secret" "$label"
 
-  rdir=$KEYS/recov/$recov/current
+  rdir=$KEYS/recov/$recov/$inst
   if [ ! -f $rdir/$label.recov ]; then
-    echo >&2 "$quis: no blob for \`$label' under recovery key \`$recov'"
+    echo >&2 "$quis: no blob for \`$label' under recovery key \`$recov/$inst'"
     exit 1
   fi
   reqsafe
-  nub=$SAFE/keys.reveal/$recov.current/nub
+  tag=$recov.$inst
+  nub=$SAFE/keys.reveal/$tag/nub
   if [ ! -f $nub ]; then
-    echo >&2 "$quis: current recovery key \`$recov' not revealed"
+    echo >&2 "$quis: current recovery key \`$recov/$inst' not revealed"
     exit 1;
   fi
   mktmp
@@ -564,7 +640,7 @@ recover () {
 
 defhelp () {
   read umsg
-  usage="usage: $quis${umsg+ }$umsg"
+  usage=$umsg
   help=$(cat)
   case "$KEYS_HELP" in t) help; exit ;; esac
 }
@@ -572,13 +648,17 @@ defhelp () {
 help () { showhelp; }
 showhelp () {
   cat <<EOF
-$usage
+Usage: $quis${usage:+ $usage}
 
 $help
 EOF
 }
 
-usage_err () { echo >&2 "$usage"; exit 1; }
+usage () {
+  : ${cmdargs=$usage}
+  echo "usage: $quis${cmdname:+ $cmdname}${cmdargs:+ $cmdargs}"
+}
+usage_err () { usage >&2; exit 1; }
 
 ###--------------------------------------------------------------------------
 ### Subcommand handling.
@@ -587,6 +667,20 @@ version () {
   echo "$PACKAGE version $VERSION"
 }
 
+unset cmdargs
+unset cmdname
+cmds=""
+defcmd () {
+  cmd=$1; shift; args=$*
+  help=$(cat)
+  eval help_$cmd=\$help
+  cmds="${cmds:+$cmds
+}$cmd $args"
+}
+
+defcmd help "[COMMAND ...]" <<EOF
+Show help about the COMMANDs, or about $quis if none are named.
+EOF
 cmd_help () {
   rc=0
   version
@@ -594,30 +688,50 @@ cmd_help () {
     0)
       cat <<EOF
 
-$usage
+Usage: $quis${usage:+ $usage}
 
 Options:
   -h		Show this help text.
   -v		Show the program version number.
 
-Commands installed:
+Commands provided:
 EOF
-      cd "$KEYSLIB"
-      for i in $prefix.*; do
-	if [ ! -x "$i" ]; then continue; fi
-	sed -n "/<<HELP/{n;s/^/	${i#$prefix.} /;p;q;}" "$i"
-      done
+      while read cmd args; do echo "	$cmd${args:+ $args}"; done <<EOF
+$cmds
+EOF
+      case ${prefix+t} in
+	t)
+	  cd $KEYSLIB
+	  for i in $prefix.*; do
+	    if [ ! -x "$i" ]; then continue; fi
+	    sed -n "/<<HELP/{n;s/^/	${i#$prefix.} /;p;q;}" "$i"
+	  done
+	  ;;
+      esac
       ;;
     *)
-      for i in "$@"; do
+      for cmd in "$@"; do
 	echo
-	if [ ! -x "$KEYSLIB/$prefix.$i" ]; then
-	  echo >&2 "$quis: unrecognized command \`$i'"
-	  rc=1
-	  continue
-	elif ! KEYS_HELP=t "$KEYSLIB/$prefix.$i"; then
-	  rc=1
-	fi
+	foundp=nil
+	while read cmdname cmdargs; do
+	  case $cmdname in "$cmd") foundp=t; break ;; esac
+	done <<EOF
+$cmds
+EOF
+	case $foundp in
+	  t)
+	    eval help=\$help_$cmdname; echo "$help"
+	    ;;
+	  nil)
+	    if [ ! -x "$KEYSLIB/$prefix.$cmd" ]; then
+	      echo >&2 "$quis: unrecognized command \`$cmd'"
+	      rc=1
+	      continue
+	    elif ! KEYS_HELP=t "$KEYSLIB/$prefix.$cmd"; then
+	      rc=1
+	    fi
+	    ;;
+	esac
       done
       ;;
   esac
@@ -625,16 +739,28 @@ EOF
 }
 
 dispatch () {
-  case $# in 0) echo >&2 "$usage"; exit 1 ;; esac
+  case $# in 0) usage_err ;; esac
   cmd=$1; shift
-  case "$cmd" in help) cmd_help "$@"; exit ;; esac
-  if [ ! -x "$KEYSLIB/$prefix.$cmd" ]; then
-    echo >&2 "$quis: unrecognized command \`$cmd'"
-    exit 1
-  fi
-
-  unset KEYS_HELP
-  exec "$KEYSLIB/$prefix.$cmd" "$@"
+  foundp=nil
+  while read cmdname cmdargs; do
+    case $cmdname in "$cmd") foundp=t; break ;; esac
+  done <<EOF
+$cmds
+EOF
+  case $foundp in
+    t)
+      OPTIND=1
+      cmd_$cmdname "$@"
+      ;;
+    nil)
+      if [ ! -x "$KEYSLIB/$prefix.$cmd" ]; then
+	echo >&2 "$quis: unrecognized command \`$cmd'"
+	exit 1
+      fi
+      unset KEYS_HELP
+      exec "$KEYSLIB/$prefix.$cmd" "$@"
+      ;;
+  esac
 }
 
 ###----- That's all, folks --------------------------------------------------