Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
fs/crypto/fname.c | 71 +++++++++++++++++++++++------------------
include/linux/fscrypt.h | 3 ++
2 files changed, 43 insertions(+), 31 deletions(-)
diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c
index 9440a44e24ac..09f09def87fc 100644
--- a/fs/crypto/fname.c
+++ b/fs/crypto/fname.c
@@ -300,6 +300,45 @@ void fscrypt_fname_free_buffer(struct fscrypt_str *crypto_str)
}
EXPORT_SYMBOL(fscrypt_fname_free_buffer);
+void fscrypt_encode_nokey_name(u32 hash, u32 minor_hash,
+ const struct fscrypt_str *iname,
+ struct fscrypt_str *oname)
+{
+ struct fscrypt_nokey_name nokey_name;
+ u32 size; /* size of the unencoded no-key name */
+
+ /*
+ * Sanity check that struct fscrypt_nokey_name doesn't have padding
+ * between fields and that its encoded size never exceeds NAME_MAX.
+ */
+ BUILD_BUG_ON(offsetofend(struct fscrypt_nokey_name, dirhash) !=
+ offsetof(struct fscrypt_nokey_name, bytes));
+ BUILD_BUG_ON(offsetofend(struct fscrypt_nokey_name, bytes) !=
+ offsetof(struct fscrypt_nokey_name, sha256));
+ BUILD_BUG_ON(BASE64_CHARS(FSCRYPT_NOKEY_NAME_MAX) > NAME_MAX);
+
+ if (hash) {
+ nokey_name.dirhash[0] = hash;
+ nokey_name.dirhash[1] = minor_hash;
+ } else {
+ nokey_name.dirhash[0] = 0;
+ nokey_name.dirhash[1] = 0;
+ }
+ if (iname->len <= sizeof(nokey_name.bytes)) {
+ memcpy(nokey_name.bytes, iname->name, iname->len);
+ size = offsetof(struct fscrypt_nokey_name, bytes[iname->len]);
+ } else {
+ memcpy(nokey_name.bytes, iname->name, sizeof(nokey_name.bytes));
+ /* Compute strong hash of remaining part of name. */
+ fscrypt_do_sha256(&iname->name[sizeof(nokey_name.bytes)],
+ iname->len - sizeof(nokey_name.bytes),
+ nokey_name.sha256);
+ size = FSCRYPT_NOKEY_NAME_MAX;
+ }
+ oname->len = base64_encode((const u8 *)&nokey_name, size, oname->name);
+}
+EXPORT_SYMBOL(fscrypt_encode_nokey_name);
+
/**
* fscrypt_fname_disk_to_usr() - convert an encrypted filename to
* user-presentable form
@@ -327,8 +366,6 @@ int fscrypt_fname_disk_to_usr(const struct inode *inode,
struct fscrypt_str *oname)
{
const struct qstr qname = FSTR_TO_QSTR(iname);
- struct fscrypt_nokey_name nokey_name;
- u32 size; /* size of the unencoded no-key name */
if (fscrypt_is_dot_dotdot(&qname)) {
oname->name[0] = '.';
@@ -343,35 +380,7 @@ int fscrypt_fname_disk_to_usr(const struct inode *inode,
if (fscrypt_has_encryption_key(inode))
return fname_decrypt(inode, iname, oname);
- /*
- * Sanity check that struct fscrypt_nokey_name doesn't have padding
- * between fields and that its encoded size never exceeds NAME_MAX.
- */
- BUILD_BUG_ON(offsetofend(struct fscrypt_nokey_name, dirhash) !=
- offsetof(struct fscrypt_nokey_name, bytes));
- BUILD_BUG_ON(offsetofend(struct fscrypt_nokey_name, bytes) !=
- offsetof(struct fscrypt_nokey_name, sha256));
- BUILD_BUG_ON(BASE64_CHARS(FSCRYPT_NOKEY_NAME_MAX) > NAME_MAX);
-
- if (hash) {
- nokey_name.dirhash[0] = hash;
- nokey_name.dirhash[1] = minor_hash;
- } else {
- nokey_name.dirhash[0] = 0;
- nokey_name.dirhash[1] = 0;
- }
- if (iname->len <= sizeof(nokey_name.bytes)) {
- memcpy(nokey_name.bytes, iname->name, iname->len);
- size = offsetof(struct fscrypt_nokey_name, bytes[iname->len]);
- } else {
- memcpy(nokey_name.bytes, iname->name, sizeof(nokey_name.bytes));
- /* Compute strong hash of remaining part of name. */
- fscrypt_do_sha256(&iname->name[sizeof(nokey_name.bytes)],
- iname->len - sizeof(nokey_name.bytes),
- nokey_name.sha256);
- size = FSCRYPT_NOKEY_NAME_MAX;
- }
- oname->len = base64_encode((const u8 *)&nokey_name, size, oname->name);
+ fscrypt_encode_nokey_name(hash, minor_hash, iname, oname);
return 0;
}
EXPORT_SYMBOL(fscrypt_fname_disk_to_usr);
diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h
index 0ddbd27a2e58..57146f9f70e7 100644
--- a/include/linux/fscrypt.h
+++ b/include/linux/fscrypt.h
@@ -202,6 +202,9 @@ static inline void fscrypt_free_filename(struct fscrypt_name *fname)
int fscrypt_fname_alloc_buffer(u32 max_encrypted_len,
struct fscrypt_str *crypto_str);
void fscrypt_fname_free_buffer(struct fscrypt_str *crypto_str);
+void fscrypt_encode_nokey_name(u32 hash, u32 minor_hash,
+ const struct fscrypt_str *iname,
+ struct fscrypt_str *oname);
int fscrypt_fname_disk_to_usr(const struct inode *inode,
u32 hash, u32 minor_hash,
const struct fscrypt_str *iname,
--
2.26.2
