From 6ddb2447846a8ece111e316a2863c2355023682d Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Thu, 16 Apr 2015 01:56:00 -0400 Subject: [PATCH] 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 Signed-off-by: Theodore Ts'o --- fs/ext4/crypto_key.c | 27 +++++++++++++++------------ fs/ext4/crypto_policy.c | 18 +++++++++++++++--- fs/ext4/ext4.h | 17 +++++++++++++---- fs/ext4/ialloc.c | 3 ++- fs/ext4/namei.c | 9 ++++++--- fs/ext4/super.c | 29 ++++++++++++++++++++++++++++- 6 files changed, 79 insertions(+), 24 deletions(-) diff --git a/fs/ext4/crypto_key.c b/fs/ext4/crypto_key.c index 572bd97..c8392af 100644 --- 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 749ed6e..30eaf9e 100644 --- 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 86d1570..0179654 100644 --- 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 850267c..2cf18a2 100644 --- 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 d201426..4f87127 100644 --- 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 1008ca2..f9ebd58 100644 --- 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. -- 2.7.4