[xfstests PATCH v2] common/encrypt: use a sub-keyring within the session keyring

[xfstests PATCH v2] common/encrypt: use a sub-keyring within the session keyring

[Eric Biggers]

From: Eric Biggers <ebiggers@google.com>

Make the encryption tests create and use a named keyring "xfstests" in
the session keyring that the tests happen to be running under, rather
than replace the session keyring using 'keyctl new_session'.
Unfortunately, the latter doesn't work when the session keyring is owned
by a non-root user, which (depending on the Linux distro) can happen if
xfstests is run in a sudo "session" rather than in a real root session.

This isn't a great solution, as the lifetime of the keyring will no
longer be tied to the tests as it should be, but it should work.  The
alternative would be the weird hack of making the 'check' script
re-execute itself using something like 'keyctl session - $0 $@'.

Reported-by: Ritesh Harjani <ritesh.list@gmail.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
---

Changed v1 => v2: rebased onto latest master branch

 common/encrypt    | 55 ++++++++++++++++++++++++++++++++++-------------
 tests/ext4/024    |  2 +-
 tests/generic/397 |  2 +-
 tests/generic/398 |  2 +-
 tests/generic/399 |  2 +-
 tests/generic/419 |  2 +-
 tests/generic/421 |  2 +-
 tests/generic/429 |  2 +-
 tests/generic/435 |  2 +-
 tests/generic/440 |  2 +-
 tests/generic/576 |  2 +-
 tests/generic/593 | 13 +++++------
 12 files changed, 57 insertions(+), 31 deletions(-)

diff --git a/common/encrypt b/common/encrypt
index 3e8c7fd3..8f3c46f6 100644
--- a/common/encrypt
+++ b/common/encrypt
@@ -121,7 +121,7 @@ _require_encryption_policy_support()
 		local keyspec=$(_add_enckey $mnt "$raw_key" | awk '{print $NF}')
 	else
 		_require_command "$KEYCTL_PROG" keyctl
-		_new_session_keyring
+		_init_session_keyring
 		local keyspec=$(_generate_session_encryption_key)
 	fi
 	if _set_encpolicy $dir $keyspec $set_encpolicy_args \
@@ -138,7 +138,7 @@ _require_encryption_policy_support()
 		_notrun "encryption policy '$set_encpolicy_args' is unusable; probably missing kernel crypto API support"
 	fi
 	if (( policy_version <= 1 )); then
-		$KEYCTL_PROG clear @s
+		$KEYCTL_PROG clear $TEST_KEYRING_ID
 	fi
 	rm -r $dir
 }
@@ -199,11 +199,30 @@ TEST_KEY_DESCRIPTOR="0000111122223333"
 # Key identifier: HKDF-SHA512(key=$TEST_RAW_KEY, salt="", info="fscrypt\0\x01")
 TEST_KEY_IDENTIFIER="69b2f6edeee720cce0577937eb8a6751"
 
-# Give the invoking shell a new session keyring.  This makes any keys we add to
-# the session keyring scoped to the lifetime of the test script.
-_new_session_keyring()
+# This is the ID of the keyring that was created by _init_session_keyring().
+# You must call _init_session_keyring() before using this.
+TEST_KEYRING_ID=
+
+# Create a test keyring within the session keyring.  Keys added to this keyring
+# will be available within the test script and all its subprocesses.  If the
+# test keyring already exists, then it is replaced.
+#
+# This used to use 'keyctl new_session' to replace the session keyring itself.
+# However, that doesn't work if a non-root user owns the session keyring.
+_init_session_keyring()
 {
-	$KEYCTL_PROG new_session >>$seqres.full
+	TEST_KEYRING_ID=$($KEYCTL_PROG newring xfstests @s)
+	if [ -z "$TEST_KEYRING_ID" ]; then
+		_fail "Failed to create test keyring in session keyring"
+	fi
+}
+
+# Check that _init_session_keyring() has been called.
+_check_session_keyring()
+{
+	if [ -z "$TEST_KEYRING_ID" ]; then
+		_fail "_init_session_keyring() must be called before using the test keyring"
+	fi
 }
 
 # Generate a key descriptor (16 character hex string)
@@ -276,6 +295,8 @@ _add_session_encryption_key()
 	local keydesc=$1
 	local raw=$2
 
+	_check_session_keyring
+
 	#
 	# Add the key to the session keyring.  The required structure is:
 	#
@@ -291,14 +312,14 @@ _add_session_encryption_key()
 	local size=$(_num_to_hex 64 4)
 	local prefix=$(_get_fs_keyprefix)
 	echo -n -e "${mode}${raw}${size}" |
-		$KEYCTL_PROG padd logon $prefix:$keydesc @s >>$seqres.full
+		$KEYCTL_PROG padd logon $prefix:$keydesc $TEST_KEYRING_ID \
+			>>$seqres.full
 }
 
 #
 # Generate a random encryption key, add it to the session keyring, and print out
 # the resulting key descriptor (example: "8bf798e1a494e1ec").  Requires the
-# keyctl program.  It's assumed the caller has already set up a test-scoped
-# session keyring using _new_session_keyring.
+# keyctl program and that _init_session_keyring() has been called.
 #
 _generate_session_encryption_key()
 {
@@ -313,18 +334,20 @@ _generate_session_encryption_key()
 # Unlink an encryption key from the session keyring, given its key descriptor.
 _unlink_session_encryption_key()
 {
+	_check_session_keyring
 	local keydesc=$1
 	local prefix=$(_get_fs_keyprefix)
-	local keyid=$($KEYCTL_PROG search @s logon $prefix:$keydesc)
+	local keyid=$($KEYCTL_PROG search $TEST_KEYRING_ID logon $prefix:$keydesc)
 	$KEYCTL_PROG unlink $keyid >>$seqres.full
 }
 
 # Revoke an encryption key from the session keyring, given its key descriptor.
 _revoke_session_encryption_key()
 {
+	_check_session_keyring
 	local keydesc=$1
 	local prefix=$(_get_fs_keyprefix)
-	local keyid=$($KEYCTL_PROG search @s logon $prefix:$keydesc)
+	local keyid=$($KEYCTL_PROG search $TEST_KEYRING_ID logon $prefix:$keydesc)
 	$KEYCTL_PROG revoke $keyid >>$seqres.full
 }
 
@@ -443,6 +466,8 @@ _add_fscrypt_provisioning_key()
 	local type=$2
 	local raw=$3
 
+	_check_session_keyring
+
 	# The format of the key payload must be:
 	#
 	#	struct fscrypt_provisioning_key_payload {
@@ -454,7 +479,7 @@ _add_fscrypt_provisioning_key()
 	local type_hex=$(_num_to_hex $type 4)
 	local reserved=$(_num_to_hex 0 4)
 	echo -n -e "${type_hex}${reserved}${raw}" |
-		$KEYCTL_PROG padd fscrypt-provisioning "$desc" @s
+		$KEYCTL_PROG padd fscrypt-provisioning "$desc" $TEST_KEYRING_ID
 }
 
 # Retrieve the encryption nonce of the given inode as a hex string.  The nonce
@@ -618,7 +643,7 @@ _require_get_ciphertext_filename_support()
 		_require_command "$DUMP_F2FS_PROG" dump.f2fs
 		_require_command "$KEYCTL_PROG" keyctl
 		_scratch_mount
-		_new_session_keyring
+		_init_session_keyring
 
 		local keydesc=$(_generate_session_encryption_key)
 		local dir=$SCRATCH_MNT/test.${FUNCNAME[0]}
@@ -629,7 +654,7 @@ _require_get_ciphertext_filename_support()
 		local inode=$(stat -c %i $file)
 
 		_scratch_unmount
-		$KEYCTL_PROG clear @s
+		$KEYCTL_PROG clear $TEST_KEYRING_ID
 
 		# 255-character filename should result in 340 base64 characters.
 		if ! $DUMP_F2FS_PROG -i $inode $SCRATCH_DEV \
@@ -912,7 +937,7 @@ _verify_ciphertext_for_encryption_policy()
 				| awk '{print $NF}')
 	else
 		local keyspec=$(_generate_key_descriptor)
-		_new_session_keyring
+		_init_session_keyring
 		_add_session_encryption_key $keyspec $raw_key
 	fi
 	local raw_key_hex=$(echo "$raw_key" | tr -d '\\x')
diff --git a/tests/ext4/024 b/tests/ext4/024
index 116adca9..11b335f0 100755
--- a/tests/ext4/024
+++ b/tests/ext4/024
@@ -18,7 +18,7 @@ _supported_fs ext4
 _require_scratch_encryption
 _require_command "$KEYCTL_PROG" keyctl
 
-_new_session_keyring
+_init_session_keyring
 
 #
 # Create an encrypted file whose size is not a multiple of the filesystem block
diff --git a/tests/generic/397 b/tests/generic/397
index 5ff65cd9..6c03f274 100755
--- a/tests/generic/397
+++ b/tests/generic/397
@@ -23,7 +23,7 @@ _require_symlinks
 _require_scratch_encryption
 _require_command "$KEYCTL_PROG" keyctl
 
-_new_session_keyring
+_init_session_keyring
 
 _scratch_mkfs_encrypted &>> $seqres.full
 _scratch_mount
diff --git a/tests/generic/398 b/tests/generic/398
index 506513c1..e2cbad54 100755
--- a/tests/generic/398
+++ b/tests/generic/398
@@ -24,7 +24,7 @@ _supported_fs generic
 _require_scratch_encryption
 _require_renameat2 exchange
 
-_new_session_keyring
+_init_session_keyring
 _scratch_mkfs_encrypted &>> $seqres.full
 _scratch_mount
 
diff --git a/tests/generic/399 b/tests/generic/399
index 55f07ae5..a5aa7107 100755
--- a/tests/generic/399
+++ b/tests/generic/399
@@ -30,7 +30,7 @@ _require_symlinks
 _require_command "$XZ_PROG" xz
 _require_command "$KEYCTL_PROG" keyctl
 
-_new_session_keyring
+_init_session_keyring
 
 #
 # Set up a small filesystem containing an encrypted directory.  64 MB is enough
diff --git a/tests/generic/419 b/tests/generic/419
index 6be7865c..5d56d64f 100755
--- a/tests/generic/419
+++ b/tests/generic/419
@@ -24,7 +24,7 @@ _require_scratch_encryption
 _require_command "$KEYCTL_PROG" keyctl
 _require_renameat2 exchange
 
-_new_session_keyring
+_init_session_keyring
 
 _scratch_mkfs_encrypted &>> $seqres.full
 _scratch_mount
diff --git a/tests/generic/421 b/tests/generic/421
index 04462d17..0c4fa8e3 100755
--- a/tests/generic/421
+++ b/tests/generic/421
@@ -20,7 +20,7 @@ _supported_fs generic
 _require_scratch_encryption
 _require_command "$KEYCTL_PROG" keyctl
 
-_new_session_keyring
+_init_session_keyring
 _scratch_mkfs_encrypted &>> $seqres.full
 _scratch_mount
 
diff --git a/tests/generic/429 b/tests/generic/429
index 558e93ca..2cf12316 100755
--- a/tests/generic/429
+++ b/tests/generic/429
@@ -35,7 +35,7 @@ _require_test_program "t_encrypted_d_revalidate"
 # Set up an encrypted directory
 _scratch_mkfs_encrypted &>> $seqres.full
 _scratch_mount
-_new_session_keyring
+_init_session_keyring
 keydesc=$(_generate_key_descriptor)
 raw_key=$(_generate_raw_encryption_key)
 mkdir $SCRATCH_MNT/edir
diff --git a/tests/generic/435 b/tests/generic/435
index 031e43cc..bb1cbb62 100755
--- a/tests/generic/435
+++ b/tests/generic/435
@@ -29,7 +29,7 @@ _require_command "$KEYCTL_PROG" keyctl
 
 # set up an encrypted directory
 
-_new_session_keyring
+_init_session_keyring
 _scratch_mkfs_encrypted &>> $seqres.full
 _scratch_mount
 mkdir $SCRATCH_MNT/edir
diff --git a/tests/generic/440 b/tests/generic/440
index f445a386..5850a8fe 100755
--- a/tests/generic/440
+++ b/tests/generic/440
@@ -25,7 +25,7 @@ _require_symlinks
 _require_command "$KEYCTL_PROG" keyctl
 
 # Set up an encryption-capable filesystem and an encryption key.
-_new_session_keyring
+_init_session_keyring
 _scratch_mkfs_encrypted &>> $seqres.full
 _scratch_mount
 keydesc=$(_generate_key_descriptor)
diff --git a/tests/generic/576 b/tests/generic/576
index 82fbdd71..3ef04953 100755
--- a/tests/generic/576
+++ b/tests/generic/576
@@ -38,7 +38,7 @@ edir=$SCRATCH_MNT/edir
 fsv_file=$edir/file.fsv
 
 # Set up an encrypted directory.
-_new_session_keyring
+_init_session_keyring
 keydesc=$(_generate_session_encryption_key)
 mkdir $edir
 _set_encpolicy $edir $keydesc
diff --git a/tests/generic/593 b/tests/generic/593
index f0610c57..2dda5d76 100755
--- a/tests/generic/593
+++ b/tests/generic/593
@@ -20,7 +20,7 @@ _supported_fs generic
 _require_scratch_encryption -v 2
 _require_command "$KEYCTL_PROG" keyctl
 
-_new_session_keyring
+_init_session_keyring
 _scratch_mkfs_encrypted &>> $seqres.full
 _scratch_mount
 _require_add_enckey_by_key_id $SCRATCH_MNT
@@ -113,25 +113,26 @@ echo -e "\n# keyctl_read() doesn't work on fscrypt-provisioning keys"
 keyid=$(_add_fscrypt_provisioning_key desc $FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR \
 	"$TEST_RAW_KEY")
 $KEYCTL_PROG read $keyid
-$KEYCTL_PROG unlink $keyid @s
+$KEYCTL_PROG unlink $keyid $TEST_KEYRING_ID
 
 echo -e "\n# Only keys with the correct fscrypt_provisioning_key_payload::type field can be added"
 echo "# ... keyring key is v1, filesystem wants v2 key"
 keyid=$(_add_fscrypt_provisioning_key desc $FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR \
 	"$TEST_RAW_KEY")
 $XFS_IO_PROG -c "add_enckey -k $keyid" $SCRATCH_MNT
-$KEYCTL_PROG unlink $keyid @s
+$KEYCTL_PROG unlink $keyid $TEST_KEYRING_ID
 
 echo "# ... keyring key is v2, filesystem wants v1 key"
 keyid=$(_add_fscrypt_provisioning_key desc $FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER \
 	"$TEST_RAW_KEY")
 $XFS_IO_PROG -c "add_enckey -k $keyid -d $TEST_KEY_DESCRIPTOR" $SCRATCH_MNT
-$KEYCTL_PROG unlink $keyid @s
+$KEYCTL_PROG unlink $keyid $TEST_KEYRING_ID
 
 echo -e "\n# Only keys of type fscrypt-provisioning can be added"
-keyid=$(head -c 64 /dev/urandom | $KEYCTL_PROG padd logon foo:desc @s)
+keyid=$(head -c 64 /dev/urandom | \
+	$KEYCTL_PROG padd logon foo:desc $TEST_KEYRING_ID)
 $XFS_IO_PROG -c "add_enckey -k $keyid" $SCRATCH_MNT
-$KEYCTL_PROG unlink $keyid @s
+$KEYCTL_PROG unlink $keyid $TEST_KEYRING_ID
 
 # success, all done
 status=0

base-commit: 4a7b35d7a76cd993ad7a62fd180e00589c73ac4b
-- 
2.35.1

Re: [xfstests PATCH v2] common/encrypt: use a sub-keyring within the session keyring

[Ritesh Harjani]

On 22/04/14 12:19AM, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@google.com>
>
> Make the encryption tests create and use a named keyring "xfstests" in
> the session keyring that the tests happen to be running under, rather
> than replace the session keyring using 'keyctl new_session'.
> Unfortunately, the latter doesn't work when the session keyring is owned
> by a non-root user, which (depending on the Linux distro) can happen if
> xfstests is run in a sudo "session" rather than in a real root session.
>
> This isn't a great solution, as the lifetime of the keyring will no
> longer be tied to the tests as it should be, but it should work.  The
> alternative would be the weird hack of making the 'check' script
> re-execute itself using something like 'keyctl session - $0 $@'.
>
> Reported-by: Ritesh Harjani <ritesh.list@gmail.com>
> Signed-off-by: Eric Biggers <ebiggers@google.com>
> ---

Thanks Eric for the quick resolution.
This fixes the mentioned issue for me. I was able to run "-g encrypt" xfstests
on my qemu session. Once all the test completed, I confirmed the keyring
named xfstests was created.

<results>
SECTION       -- ext4_4k
=========================
Ran: ext4/024 generic/395 generic/396 generic/397 generic/398 generic/399 generic/419 generic/421 generic/429 generic/435 generic/440 generic/548 generic/549 generic/550 generic/576 generic/580 generic/581 generic/582 generic/583 generic/584 generic/592 generic/593 generic/595 generic/602 generic/613 generic/621
Not run: generic/549 generic/550 generic/576 generic/583 generic/584
Passed all 26 tests

<keyring details>
qemu-> sudo keyctl show
Session Keyring
 253043311 --alswrv   1000  1000  keyring: _ses
 390003206 ---lswrv   1000 65534   \_ keyring: _uid.1000
 235062718 --alswrv      0     0   \_ keyring: xfstests
 241276015 --als--v      0     0       \_ fscrypt-provisioning: 0000111122223333
 373669133 --als--v      0     0       \_ fscrypt-provisioning: 69b2f6edeee720cce0577937eb8a6751

-ritesh