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author | Theodore Ts'o <tytso@mit.edu> | 2017-01-02 15:12:17 -0500 |
---|---|---|
committer | Theodore Ts'o <tytso@mit.edu> | 2017-01-02 15:39:46 -0500 |
commit | 5bbdcbbb396196f1c94110ad7a041e90de95c4c2 (patch) | |
tree | ecc38d3c7cfd63dec89605e2db99825ce6f91e94 /fs/crypto | |
parent | 58ae74683ae2c07cd717a91799edb50231061938 (diff) | |
download | linux-stable-5bbdcbbb396196f1c94110ad7a041e90de95c4c2.tar.gz linux-stable-5bbdcbbb396196f1c94110ad7a041e90de95c4c2.tar.bz2 linux-stable-5bbdcbbb396196f1c94110ad7a041e90de95c4c2.zip |
fscrypt: make test_dummy_encryption require a keyring key
Currently, the test_dummy_encryption ext4 mount option, which exists
only to test encrypted I/O paths with xfstests, overrides all
per-inode encryption keys with a fixed key.
This change minimizes test_dummy_encryption-specific code path changes
by supplying a fake context for directories which are not encrypted
for use when creating new directories, files, or symlinks. This
allows us to properly exercise the keyring lookup, derivation, and
context inheritance code paths.
Before mounting a file system using test_dummy_encryption, userspace
must execute the following shell commands:
mode='\x00\x00\x00\x00'
raw="$(printf ""\\\\x%02x"" $(seq 0 63))"
if lscpu | grep "Byte Order" | grep -q Little ; then
size='\x40\x00\x00\x00'
else
size='\x00\x00\x00\x40'
fi
key="${mode}${raw}${size}"
keyctl new_session
echo -n -e "${key}" | keyctl padd logon fscrypt:4242424242424242 @s
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/crypto')
-rw-r--r-- | fs/crypto/keyinfo.c | 15 | ||||
-rw-r--r-- | fs/crypto/policy.c | 22 |
2 files changed, 13 insertions, 24 deletions
diff --git a/fs/crypto/keyinfo.c b/fs/crypto/keyinfo.c index 95cd4c3b06c3..80f145c8d550 100644 --- a/fs/crypto/keyinfo.c +++ b/fs/crypto/keyinfo.c @@ -206,12 +206,16 @@ retry: res = inode->i_sb->s_cop->get_context(inode, &ctx, sizeof(ctx)); if (res < 0) { - if (!fscrypt_dummy_context_enabled(inode)) + if (!fscrypt_dummy_context_enabled(inode) || + inode->i_sb->s_cop->is_encrypted(inode)) return res; + /* Fake up a context for an unencrypted directory */ + memset(&ctx, 0, sizeof(ctx)); ctx.format = FS_ENCRYPTION_CONTEXT_FORMAT_V1; ctx.contents_encryption_mode = FS_ENCRYPTION_MODE_AES_256_XTS; ctx.filenames_encryption_mode = FS_ENCRYPTION_MODE_AES_256_CTS; - ctx.flags = 0; + memset(ctx.master_key_descriptor, 0x42, FS_KEY_DESCRIPTOR_SIZE); + res = sizeof(ctx); } else if (res != sizeof(ctx)) { return -EINVAL; } @@ -247,12 +251,6 @@ retry: if (!raw_key) goto out; - if (fscrypt_dummy_context_enabled(inode)) { - memset(raw_key, 0x42, keysize/2); - memset(raw_key+keysize/2, 0x24, keysize - (keysize/2)); - goto got_key; - } - res = validate_user_key(crypt_info, &ctx, raw_key, FS_KEY_DESC_PREFIX, FS_KEY_DESC_PREFIX_SIZE); if (res && inode->i_sb->s_cop->key_prefix) { @@ -270,7 +268,6 @@ retry: } else if (res) { goto out; } -got_key: ctfm = crypto_alloc_skcipher(cipher_str, 0, 0); if (!ctfm || IS_ERR(ctfm)) { res = ctfm ? PTR_ERR(ctfm) : -ENOMEM; diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c index 4c99972899c7..14b76da71269 100644 --- a/fs/crypto/policy.c +++ b/fs/crypto/policy.c @@ -198,9 +198,9 @@ EXPORT_SYMBOL(fscrypt_has_permitted_context); * @parent: Parent inode from which the context is inherited. * @child: Child inode that inherits the context from @parent. * @fs_data: private data given by FS. - * @preload: preload child i_crypt_info + * @preload: preload child i_crypt_info if true * - * Return: Zero on success, non-zero otherwise + * Return: 0 on success, -errno on failure */ int fscrypt_inherit_context(struct inode *parent, struct inode *child, void *fs_data, bool preload) @@ -221,19 +221,11 @@ int fscrypt_inherit_context(struct inode *parent, struct inode *child, return -ENOKEY; ctx.format = FS_ENCRYPTION_CONTEXT_FORMAT_V1; - if (fscrypt_dummy_context_enabled(parent)) { - ctx.contents_encryption_mode = FS_ENCRYPTION_MODE_AES_256_XTS; - ctx.filenames_encryption_mode = FS_ENCRYPTION_MODE_AES_256_CTS; - ctx.flags = 0; - memset(ctx.master_key_descriptor, 0x42, FS_KEY_DESCRIPTOR_SIZE); - res = 0; - } else { - ctx.contents_encryption_mode = ci->ci_data_mode; - ctx.filenames_encryption_mode = ci->ci_filename_mode; - ctx.flags = ci->ci_flags; - memcpy(ctx.master_key_descriptor, ci->ci_master_key, - FS_KEY_DESCRIPTOR_SIZE); - } + ctx.contents_encryption_mode = ci->ci_data_mode; + ctx.filenames_encryption_mode = ci->ci_filename_mode; + ctx.flags = ci->ci_flags; + memcpy(ctx.master_key_descriptor, ci->ci_master_key, + FS_KEY_DESCRIPTOR_SIZE); get_random_bytes(ctx.nonce, FS_KEY_DERIVATION_NONCE_SIZE); res = parent->i_sb->s_cop->set_context(child, &ctx, sizeof(ctx), fs_data); |