X-Git-Url: http://git.monstr.eu/?a=blobdiff_plain;f=Documentation%2Ffilesystems%2Ffscrypt.rst;h=0eb799d9d05a2cdffa8bae08abe8e16bf0dc643f;hb=e2e694b9e6f3ec7deeb233b6b0fe20b6a47b304b;hp=44b67ebd6e40d6e7bc59afd9961e44d84f03eb41;hpb=f67d6620e413a167e861ce5733c1be5a2384e0c4;p=linux-2.6-microblaze.git diff --git a/Documentation/filesystems/fscrypt.rst b/Documentation/filesystems/fscrypt.rst index 44b67ebd6e40..0eb799d9d05a 100644 --- a/Documentation/filesystems/fscrypt.rst +++ b/Documentation/filesystems/fscrypt.rst @@ -1063,11 +1063,6 @@ astute users may notice some differences in behavior: - DAX (Direct Access) is not supported on encrypted files. -- The st_size of an encrypted symlink will not necessarily give the - length of the symlink target as required by POSIX. It will actually - give the length of the ciphertext, which will be slightly longer - than the plaintext due to NUL-padding and an extra 2-byte overhead. - - The maximum length of an encrypted symlink is 2 bytes shorter than the maximum length of an unencrypted symlink. For example, on an EXT4 filesystem with a 4K block size, unencrypted symlinks can be up @@ -1235,12 +1230,12 @@ the user-supplied name to get the ciphertext. Lookups without the key are more complicated. The raw ciphertext may contain the ``\0`` and ``/`` characters, which are illegal in -filenames. Therefore, readdir() must base64-encode the ciphertext for -presentation. For most filenames, this works fine; on ->lookup(), the -filesystem just base64-decodes the user-supplied name to get back to -the raw ciphertext. +filenames. Therefore, readdir() must base64url-encode the ciphertext +for presentation. For most filenames, this works fine; on ->lookup(), +the filesystem just base64url-decodes the user-supplied name to get +back to the raw ciphertext. -However, for very long filenames, base64 encoding would cause the +However, for very long filenames, base64url encoding would cause the filename length to exceed NAME_MAX. To prevent this, readdir() actually presents long filenames in an abbreviated form which encodes a strong "hash" of the ciphertext filename, along with the optional