Commit 6ddb2447 authored by Theodore Ts'o's avatar Theodore Ts'o
Browse files

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: default avatarMichael Halcrow <mhalcrow@google.com>
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent f348c252

fs/ext4/crypto_key.c

+15 −12
Original line number Diff line number Diff line
@@ -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)

fs/ext4/crypto_policy.c

+15 −3
Original line number Diff line number Diff line
@@ -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;

fs/ext4/ext4.h

+13 −4
Original line number Diff line number Diff line
@@ -1202,6 +1202,14 @@ struct ext4_super_block { 
 */

#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
@@ -1614,7 +1622,8 @@ static inline int ext4_encrypted_inode(struct inode *inode) 
					 EXT4_FEATURE_INCOMPAT_64BIT| \

					 EXT4_FEATURE_INCOMPAT_FLEX_BG| \

					 EXT4_FEATURE_INCOMPAT_MMP | \

					 EXT4_FEATURE_INCOMPAT_INLINE_DATA)

					 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| \

fs/ext4/ialloc.c

+2 −1
Original line number Diff line number Diff line
@@ -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);

fs/ext4/namei.c

+6 −3
Original line number Diff line number Diff line
@@ -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)