LU-16444 enc: null-enc names cannot be digested form

When encrypted files have their names encrypted, long names are in
digested form in case access is done without the encryption key. The
digest is base64-encoded, and prepended with '_'.
With null encryption for file names, names are always plain text. In
this case, a legitimate '_' at the start of a name must not be
interpreted as a digested form.

sanity-sec test_54 is improved to test the case of a file whose name
starts with '_'.

Fixes: f18c87cb53 ("LU-13717 sec: handle null algo for filename encryption")
Signed-off-by: Sebastien Buisson <sbuisson@ddn.com>
Change-Id: Idaad186afd06cfbabbe1d13e78f083d12876c8ff
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/49550
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: jsimmons <jsimmons@infradead.org>
Reviewed-by: Oleg Drokin <green@whamcloud.com>

diff --git a/lustre/llite/crypto.c b/lustre/llite/crypto.c
index edc5829..d8e8173 100644 (file)
--- a/lustre/llite/crypto.c
+++ b/lustre/llite/crypto.c
@@ -251,8 +251,8 @@ int ll_setup_filename(struct inode *dir, const struct qstr *iname,
        struct qstr dname;
        int rc;
 
-       if (fid && IS_ENCRYPTED(dir) && !llcrypt_has_encryption_key(dir) &&
-           iname->name[0] == '_')
+       if (fid && IS_ENCRYPTED(dir) && llcrypt_policy_has_filename_enc(dir) &&
+           !llcrypt_has_encryption_key(dir) && iname->name[0] == '_')
                digested = 1;
 
        dname.name = iname->name + digested;

diff --git a/lustre/tests/sanity-sec.sh b/lustre/tests/sanity-sec.sh
index c1f26ec..cd0a596 100755 (executable)
--- a/lustre/tests/sanity-sec.sh
+++ b/lustre/tests/sanity-sec.sh
@@ -4322,6 +4322,7 @@ test_54() {
        local testdir2=$DIR2/$tdir/$ID0
        local testfile=$testdir/$tfile
        local testfile2=$testdir/${tfile}withveryverylongnametoexercisecode
+       local testfile3=$testdir/_${tfile}
        local tmpfile=$TMP/${tfile}.tmp
        local resfile=$TMP/${tfile}.res
        local nameenc=""
@@ -4366,6 +4367,8 @@ test_54() {
        cp $testfile $tmpfile
        $RUNAS dd if=/dev/urandom of=$testfile2 bs=127 count=1 conv=fsync ||
                error "write to encrypted file $testfile2 failed"
+       $RUNAS dd if=/dev/urandom of=$testfile3 bs=127 count=1 conv=fsync ||
+               error "write to encrypted file $testfile3 failed"
        $RUNAS mkdir $testdir/subdir || error "mkdir subdir failed"
        $RUNAS touch $testdir/subdir/subfile || error "mkdir subdir failed"
 
@@ -4374,7 +4377,7 @@ test_54() {
 
        $RUNAS ls -R $testdir || error "ls -R $testdir failed"
        local filecount=$($RUNAS find $testdir -type f | wc -l)
-       [ $filecount -eq 3 ] || error "found $filecount files"
+       [ $filecount -eq 4 ] || error "found $filecount files"
 
        # check enable_filename_encryption default value
        # tunable only available for client built against embedded llcrypt
@@ -4387,12 +4390,16 @@ test_54() {
                [ $nameenc -eq 0 ] ||
                       error "enable_filename_encryption should be 0 by default"
 
-               # $testfile and $testfile2 should exist because
+               # $testfile, $testfile2 and $testfile3 should exist because
                # names are not encrypted
                [ -f $testfile ] ||
                      error "$testfile should exist because name not encrypted"
                [ -f $testfile2 ] ||
                      error "$testfile2 should exist because name not encrypted"
+               [ -f $testfile3 ] ||
+                     error "$testfile3 should exist because name not encrypted"
+               stat $testfile3
+               [ $? -eq 0 ] || error "cannot stat $testfile3 without key"
        fi
 
        scrambledfiles=( $(find $testdir/ -maxdepth 1 -type f) )
@@ -4409,6 +4416,8 @@ test_54() {
                error "reading $testfile failed"
 
        cmp -bl $tmpfile $resfile || error "file read differs from file written"
+       stat $testfile3
+       [ $? -eq 0 ] || error "cannot stat $testfile3 with key"
 
        $RUNAS fscrypt lock --verbose $testdir ||
                error "fscrypt lock $testdir failed (2)"