reset HOME, USER(NAME), TMPDIR & SHELL in DropPrivileges

We can't cleanup the environment like e.g. sudo would do as you usually
want the environment to "leak" into these helpers, but some variables
like HOME should really not have still the value of the root user – it
could confuse the helpers (USER) and HOME isn't accessible anyhow.

Closes: 842877
(cherry picked from commit 34b491e735ad47c4805e63f3b83a659b8d10262b)

1 files changed, 32 insertions, 0 deletions

diff --git a/test/integration/skip-apt-dropprivs b/test/integration/skip-apt-dropprivs
new file mode 100755
index 000000000..e0dd741cd
--- /dev/null
+++ b/test/integration/skip-apt-dropprivs
@@ -0,0 +1,32 @@
+#!/bin/sh
+set -e
+
+TESTDIR="$(readlink -f "$(dirname "$0")")"
+. "$TESTDIR/framework"
+
+setupenvironment
+configarchitecture 'amd64'
+
+aptdropprivs() { runapt "${APTTESTHELPERSBINDIR}/aptdropprivs" "$@"; }
+
+testsuccess aptdropprivs -- /bin/true
+testsuccess aptdropprivs --user "$USER" -- /bin/true
+testsuccess aptdropprivs --user 'nobody' -- /bin/true
+testsuccess aptdropprivs --user '_apt' -- /bin/true
+
+IDBIN='/usr/bin/id'
+testsuccessequal "$("$IDBIN")" aptdropprivs --user "$USER" -- "$IDBIN"
+
+SUDOBIN='/usr/bin/sudo'
+testequal "sudo: effective uid is not 0, is /usr/bin/sudo on a file system with the 'nosuid' option set or an NFS file system without root privileges?" aptdropprivs --user 'nobody' -- "$SUDOBIN" "$IDBIN"
+
+if [ "$(id -u)" = '0' ]; then
+	testsuccessequal '_apt' aptdropprivs --user '_apt' -- "$IDBIN" '-un'
+	testsuccess aptdropprivs --user '_apt' -- '/bin/sh' '-c' 'export'
+	cp rootdir/tmp/testsuccess.output apt.env
+	testsuccessequal "export HOME='/nonexistent'" grep '^export HOME' apt.env
+	testsuccessequal "export USER='_apt'
+export USERNAME='_apt'" grep '^export USER' apt.env
+	testsuccessequal "export LOGNAME='_apt'" grep '^export LOGNAME' apt.env
+	testsuccessequal "export SHELL='/bin/sh'" grep '^export SHELL=' apt.env
+fi