ext4 crypto: enable encryption feature flag

Also add the test dummy encryption mode flag so we can more easily
test the encryption patches using xfstests.

Signed-off-by: Michael Halcrow <mhalcrow@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/crypto_key.c b/fs/ext4/crypto_key.c
index 572bd97f58dd605b323ded125ca76046fed86548..c8392af8abbbbd8fffb0a1027d5cf5c74dbb6b81 100644 (file)
--- a/fs/ext4/crypto_key.c
+++ b/fs/ext4/crypto_key.c
@@ -98,6 +98,7 @@ int ext4_generate_encryption_key(struct inode *inode)
        struct ext4_encryption_key *master_key;
        struct ext4_encryption_context ctx;
        struct user_key_payload *ukp;
+       struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
        int res = ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
                                 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
                                 &ctx, sizeof(ctx));
@@ -109,6 +110,20 @@ int ext4_generate_encryption_key(struct inode *inode)
        }
        res = 0;
 
+       if (S_ISREG(inode->i_mode))
+               crypt_key->mode = ctx.contents_encryption_mode;
+       else if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
+               crypt_key->mode = ctx.filenames_encryption_mode;
+       else {
+               printk(KERN_ERR "ext4 crypto: Unsupported inode type.\n");
+               BUG();
+       }
+       crypt_key->size = ext4_encryption_key_size(crypt_key->mode);
+       BUG_ON(!crypt_key->size);
+       if (DUMMY_ENCRYPTION_ENABLED(sbi)) {
+               memset(crypt_key->raw, 0x42, EXT4_AES_256_XTS_KEY_SIZE);
+               goto out;
+       }
        memcpy(full_key_descriptor, EXT4_KEY_DESC_PREFIX,
               EXT4_KEY_DESC_PREFIX_SIZE);
        sprintf(full_key_descriptor + EXT4_KEY_DESC_PREFIX_SIZE,
@@ -129,21 +144,9 @@ int ext4_generate_encryption_key(struct inode *inode)
                goto out;
        }
        master_key = (struct ext4_encryption_key *)ukp->data;
-
-       if (S_ISREG(inode->i_mode))
-               crypt_key->mode = ctx.contents_encryption_mode;
-       else if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
-               crypt_key->mode = ctx.filenames_encryption_mode;
-       else {
-               printk(KERN_ERR "ext4 crypto: Unsupported inode type.\n");
-               BUG();
-       }
-       crypt_key->size = ext4_encryption_key_size(crypt_key->mode);
-       BUG_ON(!crypt_key->size);
        BUILD_BUG_ON(EXT4_AES_128_ECB_KEY_SIZE !=
                     EXT4_KEY_DERIVATION_NONCE_SIZE);
        BUG_ON(master_key->size != EXT4_AES_256_XTS_KEY_SIZE);
-       BUG_ON(crypt_key->size < EXT4_AES_256_CBC_KEY_SIZE);
        res = ext4_derive_key_aes(ctx.nonce, master_key->raw, crypt_key->raw);
 out:
        if (keyring_key)

diff --git a/fs/ext4/crypto_policy.c b/fs/ext4/crypto_policy.c
index 749ed6e91e50b6ed2a6f7e9b75ee3e3b2796672f..30eaf9e9864a967db328bbebc18211ff4796961e 100644 (file)
--- a/fs/ext4/crypto_policy.c
+++ b/fs/ext4/crypto_policy.c
@@ -169,13 +169,25 @@ int ext4_inherit_context(struct inode *parent, struct inode *child)
                                 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
                                 &ctx, sizeof(ctx));
 
-       if (res != sizeof(ctx))
-               return -ENOENT;
-
+       if (res != sizeof(ctx)) {
+               if (DUMMY_ENCRYPTION_ENABLED(EXT4_SB(parent->i_sb))) {
+                       ctx.format = EXT4_ENCRYPTION_CONTEXT_FORMAT_V1;
+                       ctx.contents_encryption_mode =
+                               EXT4_ENCRYPTION_MODE_AES_256_XTS;
+                       ctx.filenames_encryption_mode =
+                               EXT4_ENCRYPTION_MODE_AES_256_CTS;
+                       memset(ctx.master_key_descriptor, 0x42,
+                              EXT4_KEY_DESCRIPTOR_SIZE);
+                       res = 0;
+               } else {
+                       goto out;
+               }
+       }
        get_random_bytes(ctx.nonce, EXT4_KEY_DERIVATION_NONCE_SIZE);
        res = ext4_xattr_set(child, EXT4_XATTR_INDEX_ENCRYPTION,
                             EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, &ctx,
                             sizeof(ctx), 0);
+out:
        if (!res)
                ext4_set_inode_flag(child, EXT4_INODE_ENCRYPT);
        return res;

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 86d15706d27a552184ded0cef192daf2848a8201..0179654faf7925660884561a62e1bbd719f51c30 100644 (file)
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1200,8 +1200,16 @@ struct ext4_super_block {
 /*
  * run-time mount flags
  */
-#define EXT4_MF_MNTDIR_SAMPLED 0x0001
-#define EXT4_MF_FS_ABORTED     0x0002  /* Fatal error detected */
+#define EXT4_MF_MNTDIR_SAMPLED         0x0001
+#define EXT4_MF_FS_ABORTED             0x0002  /* Fatal error detected */
+#define EXT4_MF_TEST_DUMMY_ENCRYPTION  0x0004
+
+#ifdef CONFIG_EXT4_FS_ENCRYPTION
+#define DUMMY_ENCRYPTION_ENABLED(sbi) (unlikely((sbi)->s_mount_flags & \
+                                               EXT4_MF_TEST_DUMMY_ENCRYPTION))
+#else
+#define DUMMY_ENCRYPTION_ENABLED(sbi) (0)
+#endif
 
 /* Number of quota types we support */
 #define EXT4_MAXQUOTAS 2
@@ -1613,8 +1621,9 @@ static inline int ext4_encrypted_inode(struct inode *inode)
                                         EXT4_FEATURE_INCOMPAT_EXTENTS| \
                                         EXT4_FEATURE_INCOMPAT_64BIT| \
                                         EXT4_FEATURE_INCOMPAT_FLEX_BG| \
-                                        EXT4_FEATURE_INCOMPAT_MMP |    \
-                                        EXT4_FEATURE_INCOMPAT_INLINE_DATA)
+                                        EXT4_FEATURE_INCOMPAT_MMP | \
+                                        EXT4_FEATURE_INCOMPAT_INLINE_DATA | \
+                                        EXT4_FEATURE_INCOMPAT_ENCRYPT)
 #define EXT4_FEATURE_RO_COMPAT_SUPP    (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
                                         EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
                                         EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \

diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 850267c89407eacd09db87873c35211ad68264d0..2cf18a2d5c72b233d52da1c22ed8047ad8cff40c 100644 (file)
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -998,7 +998,8 @@ got:
 
        /* If the directory encrypted, then we should encrypt the inode. */
        if ((S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) &&
-           ext4_encrypted_inode(dir))
+           (ext4_encrypted_inode(dir) ||
+            DUMMY_ENCRYPTION_ENABLED(sbi)))
                ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
 
        ext4_set_inode_flags(inode);

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index d201426b8d3924d1549010d03998f1e94546a957..4f87127f781f4e5eb062eb9459901e5f46a4f08a 100644 (file)
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -2582,7 +2582,8 @@ retry:
                ext4_set_aops(inode);
                err = 0;
 #ifdef CONFIG_EXT4_FS_ENCRYPTION
-               if (!err && ext4_encrypted_inode(dir)) {
+               if (!err && (ext4_encrypted_inode(dir) ||
+                            DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb)))) {
                        err = ext4_inherit_context(dir, inode);
                        if (err) {
                                clear_nlink(inode);
@@ -2777,7 +2778,8 @@ retry:
        if (err)
                goto out_clear_inode;
 #ifdef CONFIG_EXT4_FS_ENCRYPTION
-       if (ext4_encrypted_inode(dir)) {
+       if (ext4_encrypted_inode(dir) ||
+           DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb))) {
                err = ext4_inherit_context(dir, inode);
                if (err)
                        goto out_clear_inode;
@@ -3202,7 +3204,8 @@ static int ext4_symlink(struct inode *dir,
        disk_link.len = len + 1;
        disk_link.name = (char *) symname;
 
-       encryption_required = ext4_encrypted_inode(dir);
+       encryption_required = (ext4_encrypted_inode(dir) ||
+                              DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb)));
        if (encryption_required)
                disk_link.len = encrypted_symlink_data_len(len) + 1;
        if (disk_link.len > dir->i_sb->s_blocksize)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 1008ca258de45b731073b3a09dfb64559045dde2..f9ebd58f40dda7128f335ce508df0bd5715c5d53 100644 (file)
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1106,7 +1106,7 @@ enum {
        Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
        Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
        Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
-       Opt_data_err_abort, Opt_data_err_ignore,
+       Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
        Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
        Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
        Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
@@ -1197,6 +1197,7 @@ static const match_table_t tokens = {
        {Opt_init_itable, "init_itable"},
        {Opt_noinit_itable, "noinit_itable"},
        {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
+       {Opt_test_dummy_encryption, "test_dummy_encryption"},
        {Opt_removed, "check=none"},    /* mount option from ext2/3 */
        {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
        {Opt_removed, "reservation"},   /* mount option from ext2/3 */
@@ -1398,6 +1399,7 @@ static const struct mount_opts {
        {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
        {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
        {Opt_max_dir_size_kb, 0, MOPT_GTE0},
+       {Opt_test_dummy_encryption, 0, MOPT_GTE0},
        {Opt_err, 0, 0}
 };
 
@@ -1574,6 +1576,15 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token,
                }
                *journal_ioprio =
                        IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
+       } else if (token == Opt_test_dummy_encryption) {
+#ifdef CONFIG_EXT4_FS_ENCRYPTION
+               sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
+               ext4_msg(sb, KERN_WARNING,
+                        "Test dummy encryption mode enabled");
+#else
+               ext4_msg(sb, KERN_WARNING,
+                        "Test dummy encryption mount option ignored");
+#endif
        } else if (m->flags & MOPT_DATAJ) {
                if (is_remount) {
                        if (!sbi->s_journal)
@@ -2671,11 +2682,13 @@ static struct attribute *ext4_attrs[] = {
 EXT4_INFO_ATTR(lazy_itable_init);
 EXT4_INFO_ATTR(batched_discard);
 EXT4_INFO_ATTR(meta_bg_resize);
+EXT4_INFO_ATTR(encryption);
 
 static struct attribute *ext4_feat_attrs[] = {
        ATTR_LIST(lazy_itable_init),
        ATTR_LIST(batched_discard),
        ATTR_LIST(meta_bg_resize),
+       ATTR_LIST(encryption),
        NULL,
 };
 
@@ -3683,6 +3696,13 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
                }
        }
 
+       if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_ENCRYPT) &&
+           es->s_encryption_level) {
+               ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
+                        es->s_encryption_level);
+               goto failed_mount;
+       }
+
        if (sb->s_blocksize != blocksize) {
                /* Validate the filesystem blocksize */
                if (!sb_set_blocksize(sb, blocksize)) {
@@ -4045,6 +4065,13 @@ no_journal:
                }
        }
 
+       if (unlikely(sbi->s_mount_flags & EXT4_MF_TEST_DUMMY_ENCRYPTION) &&
+           !(sb->s_flags & MS_RDONLY) &&
+           !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_ENCRYPT)) {
+               EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_ENCRYPT);
+               ext4_commit_super(sb, 1);
+       }
+
        /*
         * Get the # of file system overhead blocks from the
         * superblock if present.