From: Eric Biggers <ebiggers@kernel.org>
To: Jeff Layton <jlayton@kernel.org>
Cc: ceph-devel@vger.kernel.org, linux-fscrypt@vger.kernel.org,
linux-fsdevel@vger.kernel.org
Subject: Re: [RFC PATCH v3 02/16] fscrypt: export fscrypt_base64_encode and fscrypt_base64_decode
Date: Mon, 14 Sep 2020 16:44:00 -0700 [thread overview]
Message-ID: <20200914234400.GB899@sol.localdomain> (raw)
In-Reply-To: <20200914191707.380444-3-jlayton@kernel.org>
On Mon, Sep 14, 2020 at 03:16:53PM -0400, Jeff Layton wrote:
> Ceph will need to base64-encode some encrypted inode names, so make
> these routines, and FSCRYPT_BASE64_CHARS available to modules.
"inode names" => "filenames"
>
> Signed-off-by: Jeff Layton <jlayton@kernel.org>
> ---
> fs/crypto/fname.c | 59 ++++++++++++++++++++++++++++++++++-------
> include/linux/fscrypt.h | 4 +++
> 2 files changed, 53 insertions(+), 10 deletions(-)
>
> diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c
> index eb13408b50a7..a1cb6c2c50c4 100644
> --- a/fs/crypto/fname.c
> +++ b/fs/crypto/fname.c
> @@ -187,10 +187,8 @@ static int fname_decrypt(const struct inode *inode,
> static const char lookup_table[65] =
> "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+,";
>
> -#define BASE64_CHARS(nbytes) DIV_ROUND_UP((nbytes) * 4, 3)
> -
> /**
> - * base64_encode() - base64-encode some bytes
> + * fscrypt_base64_encode() - base64-encode some bytes
> * @src: the bytes to encode
> * @len: number of bytes to encode
> * @dst: (output) the base64-encoded string. Not NUL-terminated.
> @@ -200,7 +198,7 @@ static const char lookup_table[65] =
> *
> * Return: length of the encoded string
> */
> -static int base64_encode(const u8 *src, int len, char *dst)
> +int fscrypt_base64_encode(const u8 *src, int len, char *dst)
> {
> int i, bits = 0, ac = 0;
> char *cp = dst;
> @@ -218,8 +216,9 @@ static int base64_encode(const u8 *src, int len, char *dst)
> *cp++ = lookup_table[ac & 0x3f];
> return cp - dst;
> }
> +EXPORT_SYMBOL(fscrypt_base64_encode);
>
> -static int base64_decode(const char *src, int len, u8 *dst)
> +int fscrypt_base64_decode(const char *src, int len, u8 *dst)
fscrypt_base64_decode() could use a kerneldoc comment, now that it will be
exported for filesystems to use.
> +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(FSCRYPT_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 = fscrypt_base64_encode((const u8 *)&nokey_name, size, oname->name);
> +}
> +EXPORT_SYMBOL(fscrypt_encode_nokey_name);
fscrypt_encode_nokey_name() still isn't actually used in this patchset. Also,
the commit message doesn't mention it; it only mentions the base64 encoding and
decoding.
> +
> /**
> * fscrypt_fname_disk_to_usr() - convert an encrypted filename to
> * user-presentable form
> @@ -351,7 +390,7 @@ int fscrypt_fname_disk_to_usr(const struct inode *inode,
> 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);
> + BUILD_BUG_ON(FSCRYPT_BASE64_CHARS(FSCRYPT_NOKEY_NAME_MAX) > NAME_MAX);
>
> if (hash) {
> nokey_name.dirhash[0] = hash;
> @@ -371,7 +410,7 @@ int fscrypt_fname_disk_to_usr(const struct inode *inode,
> nokey_name.sha256);
> size = FSCRYPT_NOKEY_NAME_MAX;
> }
> - oname->len = base64_encode((const u8 *)&nokey_name, size, oname->name);
> + oname->len = fscrypt_base64_encode((const u8 *)&nokey_name, size, oname->name);
Personally I still prefer keeping keeping lines at or below the traditional 80
column limit, at least in existing files, and not introducing random longer
lines... I.e. pass --max-line-length=80 to checkpatch.
> diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h
> index b3b0c5675c6b..95dddba3ed00 100644
> --- a/include/linux/fscrypt.h
> +++ b/include/linux/fscrypt.h
> @@ -182,6 +182,10 @@ void fscrypt_free_inode(struct inode *inode);
> int fscrypt_drop_inode(struct inode *inode);
>
> /* fname.c */
> +#define FSCRYPT_BASE64_CHARS(nbytes) DIV_ROUND_UP((nbytes) * 4, 3)
> +
> +int fscrypt_base64_encode(const u8 *src, int len, char *dst);
> +int fscrypt_base64_decode(const char *src, int len, u8 *dst);
> int fscrypt_setup_filename(struct inode *inode, const struct qstr *iname,
> int lookup, struct fscrypt_name *fname);
Aren't stubs for !CONFIG_FS_ENCRYPTION needed?
- Eric
next prev parent reply other threads:[~2020-09-14 23:44 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-14 19:16 [RFC PATCH v3 00/16] ceph+fscrypt: context, filename and symlink support Jeff Layton
2020-09-14 19:16 ` [RFC PATCH v3 01/16] vfs: export new_inode_pseudo Jeff Layton
2020-09-14 23:33 ` Eric Biggers
2020-09-23 3:41 ` Al Viro
2020-09-23 11:19 ` Jeff Layton
2020-09-14 19:16 ` [RFC PATCH v3 02/16] fscrypt: export fscrypt_base64_encode and fscrypt_base64_decode Jeff Layton
2020-09-14 23:44 ` Eric Biggers [this message]
2020-09-14 19:16 ` [RFC PATCH v3 03/16] fscrypt: export fscrypt_d_revalidate Jeff Layton
2020-09-15 0:04 ` Eric Biggers
2020-09-14 19:16 ` [RFC PATCH v3 04/16] fscrypt: add fscrypt_context_for_new_inode Jeff Layton
2020-09-15 0:15 ` Eric Biggers
2020-09-14 19:16 ` [RFC PATCH v3 05/16] fscrypt: make fscrypt_fname_disk_to_usr return whether result is nokey name Jeff Layton
2020-09-15 0:23 ` Eric Biggers
2020-09-14 19:16 ` [RFC PATCH v3 06/16] ceph: add fscrypt ioctls Jeff Layton
2020-09-15 0:45 ` Eric Biggers
2020-09-15 12:08 ` Jeff Layton
2020-09-14 19:16 ` [RFC PATCH v3 07/16] ceph: crypto context handling for ceph Jeff Layton
2020-09-15 1:00 ` Eric Biggers
2020-09-14 19:16 ` [RFC PATCH v3 08/16] ceph: implement -o test_dummy_encryption mount option Jeff Layton
2020-09-15 1:23 ` Eric Biggers
2020-09-16 12:49 ` Jeff Layton
2020-09-14 19:17 ` [RFC PATCH v3 09/16] ceph: preallocate inode for ops that may create one Jeff Layton
2020-09-15 1:30 ` Eric Biggers
2020-09-16 12:41 ` Jeff Layton
2020-09-14 19:17 ` [RFC PATCH v3 10/16] ceph: add routine to create context prior to RPC Jeff Layton
2020-09-15 1:37 ` Eric Biggers
2020-09-16 12:18 ` Jeff Layton
2020-09-14 19:17 ` [RFC PATCH v3 11/16] ceph: make ceph_msdc_build_path use ref-walk Jeff Layton
2020-09-14 19:17 ` [RFC PATCH v3 12/16] ceph: add encrypted fname handling to ceph_mdsc_build_path Jeff Layton
2020-09-15 1:41 ` Eric Biggers
2020-09-16 12:30 ` Jeff Layton
2020-09-16 17:36 ` Eric Biggers
2020-09-16 18:04 ` Jeff Layton
2020-09-16 18:42 ` Eric Biggers
2020-09-14 19:17 ` [RFC PATCH v3 13/16] ceph: make d_revalidate call fscrypt revalidator for encrypted dentries Jeff Layton
2020-09-14 19:17 ` [RFC PATCH v3 14/16] ceph: add support to readdir for encrypted filenames Jeff Layton
2020-09-15 1:57 ` Eric Biggers
2020-09-15 13:27 ` Jeff Layton
2020-09-15 20:40 ` Eric Biggers
2020-09-16 12:16 ` Jeff Layton
2020-09-14 19:17 ` [RFC PATCH v3 15/16] ceph: add fscrypt support to ceph_fill_trace Jeff Layton
2020-09-14 19:17 ` [RFC PATCH v3 16/16] ceph: create symlinks with encrypted and base64-encoded targets Jeff Layton
2020-09-15 2:07 ` Eric Biggers
2020-09-15 14:05 ` Jeff Layton
2020-09-15 20:49 ` Eric Biggers
2020-09-16 12:15 ` Jeff Layton
2020-09-15 2:13 ` [RFC PATCH v3 00/16] ceph+fscrypt: context, filename and symlink support Eric Biggers
2020-09-15 13:38 ` Jeff Layton
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