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-rw-r--r--fs/crypto/fname.c36
-rw-r--r--fs/crypto/fscrypt_private.h9
-rw-r--r--fs/crypto/hooks.c6
-rw-r--r--include/linux/fscrypt.h4
4 files changed, 40 insertions, 15 deletions
diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c
index 14e0ef5e9a20..12bd61d20f69 100644
--- a/fs/crypto/fname.c
+++ b/fs/crypto/fname.c
@@ -86,7 +86,8 @@ static inline bool fscrypt_is_dot_dotdot(const struct qstr *str)
/**
* fscrypt_fname_encrypt() - encrypt a filename
* @inode: inode of the parent directory (for regular filenames)
- * or of the symlink (for symlink targets)
+ * or of the symlink (for symlink targets). Key must already be
+ * set up.
* @iname: the filename to encrypt
* @out: (output) the encrypted filename
* @olen: size of the encrypted filename. It must be at least @iname->len.
@@ -137,6 +138,7 @@ int fscrypt_fname_encrypt(const struct inode *inode, const struct qstr *iname,
return 0;
}
+EXPORT_SYMBOL_GPL(fscrypt_fname_encrypt);
/**
* fname_decrypt() - decrypt a filename
@@ -264,9 +266,9 @@ static int fscrypt_base64url_decode(const char *src, int srclen, u8 *dst)
return bp - dst;
}
-bool fscrypt_fname_encrypted_size(const union fscrypt_policy *policy,
- u32 orig_len, u32 max_len,
- u32 *encrypted_len_ret)
+bool __fscrypt_fname_encrypted_size(const union fscrypt_policy *policy,
+ u32 orig_len, u32 max_len,
+ u32 *encrypted_len_ret)
{
int padding = 4 << (fscrypt_policy_flags(policy) &
FSCRYPT_POLICY_FLAGS_PAD_MASK);
@@ -281,6 +283,29 @@ bool fscrypt_fname_encrypted_size(const union fscrypt_policy *policy,
}
/**
+ * fscrypt_fname_encrypted_size() - calculate length of encrypted filename
+ * @inode: parent inode of dentry name being encrypted. Key must
+ * already be set up.
+ * @orig_len: length of the original filename
+ * @max_len: maximum length to return
+ * @encrypted_len_ret: where calculated length should be returned (on success)
+ *
+ * Filenames that are shorter than the maximum length may have their lengths
+ * increased slightly by encryption, due to padding that is applied.
+ *
+ * Return: false if the orig_len is greater than max_len. Otherwise, true and
+ * fill out encrypted_len_ret with the length (up to max_len).
+ */
+bool fscrypt_fname_encrypted_size(const struct inode *inode, u32 orig_len,
+ u32 max_len, u32 *encrypted_len_ret)
+{
+ return __fscrypt_fname_encrypted_size(&inode->i_crypt_info->ci_policy,
+ orig_len, max_len,
+ encrypted_len_ret);
+}
+EXPORT_SYMBOL_GPL(fscrypt_fname_encrypted_size);
+
+/**
* fscrypt_fname_alloc_buffer() - allocate a buffer for presented filenames
* @max_encrypted_len: maximum length of encrypted filenames the buffer will be
* used to present
@@ -435,8 +460,7 @@ int fscrypt_setup_filename(struct inode *dir, const struct qstr *iname,
return ret;
if (fscrypt_has_encryption_key(dir)) {
- if (!fscrypt_fname_encrypted_size(&dir->i_crypt_info->ci_policy,
- iname->len, NAME_MAX,
+ if (!fscrypt_fname_encrypted_size(dir, iname->len, NAME_MAX,
&fname->crypto_buf.len))
return -ENAMETOOLONG;
fname->crypto_buf.name = kmalloc(fname->crypto_buf.len,
diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h
index 6b4c8094cc7b..11fe9d213ae1 100644
--- a/fs/crypto/fscrypt_private.h
+++ b/fs/crypto/fscrypt_private.h
@@ -297,14 +297,11 @@ void fscrypt_generate_iv(union fscrypt_iv *iv, u64 lblk_num,
const struct fscrypt_info *ci);
/* fname.c */
-int fscrypt_fname_encrypt(const struct inode *inode, const struct qstr *iname,
- u8 *out, unsigned int olen);
-bool fscrypt_fname_encrypted_size(const union fscrypt_policy *policy,
- u32 orig_len, u32 max_len,
- u32 *encrypted_len_ret);
+bool __fscrypt_fname_encrypted_size(const union fscrypt_policy *policy,
+ u32 orig_len, u32 max_len,
+ u32 *encrypted_len_ret);
/* hkdf.c */
-
struct fscrypt_hkdf {
struct crypto_shash *hmac_tfm;
};
diff --git a/fs/crypto/hooks.c b/fs/crypto/hooks.c
index af74599ae1cf..7c01025879b3 100644
--- a/fs/crypto/hooks.c
+++ b/fs/crypto/hooks.c
@@ -228,9 +228,9 @@ int fscrypt_prepare_symlink(struct inode *dir, const char *target,
* counting it (even though it is meaningless for ciphertext) is simpler
* for now since filesystems will assume it is there and subtract it.
*/
- if (!fscrypt_fname_encrypted_size(policy, len,
- max_len - sizeof(struct fscrypt_symlink_data),
- &disk_link->len))
+ if (!__fscrypt_fname_encrypted_size(policy, len,
+ max_len - sizeof(struct fscrypt_symlink_data),
+ &disk_link->len))
return -ENAMETOOLONG;
disk_link->len += sizeof(struct fscrypt_symlink_data);
diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h
index e60d57c99cb6..5926a4081c6d 100644
--- a/include/linux/fscrypt.h
+++ b/include/linux/fscrypt.h
@@ -327,6 +327,10 @@ void fscrypt_free_inode(struct inode *inode);
int fscrypt_drop_inode(struct inode *inode);
/* fname.c */
+int fscrypt_fname_encrypt(const struct inode *inode, const struct qstr *iname,
+ u8 *out, unsigned int olen);
+bool fscrypt_fname_encrypted_size(const struct inode *inode, u32 orig_len,
+ u32 max_len, u32 *encrypted_len_ret);
int fscrypt_setup_filename(struct inode *inode, const struct qstr *iname,
int lookup, struct fscrypt_name *fname);