From: Mark Wooding <mdw@distorted.org.uk>
Date: Sun, 8 Jan 2012 00:45:36 +0000 (+0000)
Subject: Programs invoke themselves via `userv' if necessary.
X-Git-Tag: 0.99.2~41
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/distorted-keys/commitdiff_plain/4c8c406559cd6b201004955a3db7cb3386a0f00d?hp=d516ebd0d3928deae4cf80a113d6ccf1f666bfe6

Programs invoke themselves via `userv' if necessary.

This will prevent the permissions in the key store being messed up.  To
this end:

  * Move `cryptop' to @bindir@ where we can expect users to find it, and
    move `keys' to @sbindir@ where only administrators are likely to
    look.

  * Add a new userv service for `keys', with some configuration files
    listing the permitted users.
---

diff --git a/Makefile.am b/Makefile.am
index 2898615..1d362c8 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -81,7 +81,7 @@ extract-profile: extract-profile.in Makefile
 ### Main driver program and commands.
 
 ## Main driver.
-bin_SCRIPTS		+= keys
+sbin_SCRIPTS		+= keys
 EXTRA_DIST		+= keys.in
 CLEANFILES		+= keys
 keys: keys.in Makefile
@@ -111,7 +111,7 @@ dist_pkglib_SCRIPTS	+= keys.stash
 ### Crypto operations.
 
 ## Main driver program.
-sbin_SCRIPTS		+= cryptop
+bin_SCRIPTS		+= cryptop
 EXTRA_DIST		+= cryptop.in
 CLEANFILES		+= cryptop
 cryptop: cryptop.in Makefile
@@ -170,4 +170,6 @@ EXTRA_DIST		+= debian/rules debian/compat
 EXTRA_DIST		+= debian/distorted-keys.install
 EXTRA_DIST		+= debian/distorted-keys.postinst
 
+EXTRA_DIST		+= debian/admin.users debian/admin.groups
+
 ###----- That's all, folks --------------------------------------------------
diff --git a/cryptop.in b/cryptop.in
index 7b38a0a..064b595 100755
--- a/cryptop.in
+++ b/cryptop.in
@@ -34,6 +34,8 @@ export ETC KEYS KEYSLIB
 usage="usage: $quis COMMAND [ARGUMENTS ...]"
 prefix=cryptop
 
+runas @user@ cryptop "$@"
+
 ## Parse options.
 while getopts "hv" opt; do
   case "$opt" in
diff --git a/debian/admin.groups b/debian/admin.groups
new file mode 100644
index 0000000..0b25372
--- /dev/null
+++ b/debian/admin.groups
@@ -0,0 +1,3 @@
+### -*-conf-*-
+###
+### Groups with administrative privileges, one per line.
diff --git a/debian/admin.users b/debian/admin.users
new file mode 100644
index 0000000..a48d55d
--- /dev/null
+++ b/debian/admin.users
@@ -0,0 +1,5 @@
+### -*-conf-*-
+###
+### Users with administrative privileges, one per line.
+
+root
diff --git a/debian/distorted-keys.install b/debian/distorted-keys.install
index bd97052..83b30ea 100644
--- a/debian/distorted-keys.install
+++ b/debian/distorted-keys.install
@@ -1 +1,3 @@
 debian/build/userv/distorted-keys	/etc/userv/default.d
+debian/admin.users			/etc/distorted-keys
+debian/admin.groups			/etc/distorted-keys
diff --git a/keyfunc.sh.in b/keyfunc.sh.in
index b55bd99..6316816 100644
--- a/keyfunc.sh.in
+++ b/keyfunc.sh.in
@@ -129,6 +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.
 
diff --git a/keys.in b/keys.in
index 2676d56..5baa9f5 100755
--- a/keys.in
+++ b/keys.in
@@ -34,6 +34,8 @@ export ETC KEYS KEYSLIB
 usage="usage: $quis COMMAND [ARGUMENTS ...]"
 prefix=keys
 
+runas @user@ keys "$@"
+
 ## Parse options.
 while getopts "hv" opt; do
   case "$opt" in
diff --git a/userv/distorted-keys.in b/userv/distorted-keys.in
index 2f618aa..07ecd4a 100644
--- a/userv/distorted-keys.in
+++ b/userv/distorted-keys.in
@@ -14,7 +14,24 @@ if ( glob service cryptop
 	require-fd 1-2 write
 	ignore-fd 3-
 	no-set-environment
-	execute @sbindir@/cryptop
+	execute @bindir@/cryptop
+fi
+
+###--------------------------------------------------------------------------
+### Key administration operations.
+
+if ( glob service keys
+   & glob service-user @user@
+   & ( grep calling-user @pkgconfdir@/admin.users
+     | grep calling-group @pkgconfdir@/admin.groups
+     )
+   )
+	no-suppress-args
+	require-fd 0 read
+	require-fd 1-2 write
+	ignore-fd 3-
+	no-set-environment
+	execute @sbindir@/keys
 fi
 
 ###--------------------------------------------------------------------------