[PATCH] ksmbd: fix wrong signingkey creation when encryption is AES256

[PATCH] ksmbd: fix wrong signingkey creation when encryption is AES256

[Namjae Jeon]

MacOS and Win11 support AES256 encrytion and it is included in the cipher
array of encryption context. Especially on macOS, The most preferred
cipher is AES256. Connecting to ksmbd fails on newer MacOS clients that
support AES256 encryption. MacOS send disconnect request after receiving
final session setup response from ksmbd. Because final session setup is
signed with signing key was generated incorrectly.
For signging key, 'L' value should be initialized to 128 if key size is
16bytes.

Reported-by: Miao Lihua <441884205@qq.com>
Tested-by: Miao Lihua <441884205@qq.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
---
 fs/ksmbd/auth.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/ksmbd/auth.c b/fs/ksmbd/auth.c
index 6e61b5bc7d86..cead696b656a 100644
--- a/fs/ksmbd/auth.c
+++ b/fs/ksmbd/auth.c
@@ -727,8 +727,9 @@ static int generate_key(struct ksmbd_conn *conn, struct ksmbd_session *sess,
 		goto smb3signkey_ret;
 	}
 
-	if (conn->cipher_type == SMB2_ENCRYPTION_AES256_CCM ||
-	    conn->cipher_type == SMB2_ENCRYPTION_AES256_GCM)
+	if (key_size == SMB3_ENC_DEC_KEY_SIZE &&
+	    (conn->cipher_type == SMB2_ENCRYPTION_AES256_CCM ||
+	     conn->cipher_type == SMB2_ENCRYPTION_AES256_GCM))
 		rc = crypto_shash_update(CRYPTO_HMACSHA256(ctx), L256, 4);
 	else
 		rc = crypto_shash_update(CRYPTO_HMACSHA256(ctx), L128, 4);
-- 
2.25.1

[PATCH] ksmbd: set FILE_NAMED_STREAMS attribute in FS_ATTRIBUTE_INFORMATION

[Namjae Jeon]

If vfs objects = streams_xattr in ksmbd.conf FILE_NAMED_STREAMS should
be set to Attributes in FS_ATTRIBUTE_INFORMATION. MacOS client show
"Format: SMB (Unknown)" on faked NTFS and no streams support.

Reported-by: Miao Lihua <441884205@qq.com>
Tested-by: Miao Lihua <441884205@qq.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
---
 fs/ksmbd/smb2pdu.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
index 013fd6452942..c774af83b5dc 100644
--- a/fs/ksmbd/smb2pdu.c
+++ b/fs/ksmbd/smb2pdu.c
@@ -4936,6 +4936,10 @@ static int smb2_get_info_filesystem(struct ksmbd_work *work,
 
 		info->Attributes |= cpu_to_le32(server_conf.share_fake_fscaps);
 
+		if (test_share_config_flag(work->tcon->share_conf,
+		    KSMBD_SHARE_FLAG_STREAMS))
+			info->Attributes |= FILE_NAMED_STREAMS;
+
 		info->MaxPathNameComponentLength = cpu_to_le32(stfs.f_namelen);
 		len = smbConvertToUTF16((__le16 *)info->FileSystemName,
 					"NTFS", PATH_MAX, conn->local_nls, 0);
-- 
2.25.1

Re: [PATCH] ksmbd: fix wrong signingkey creation when encryption is AES256

[Steve French]

FYI - Linux client also supports AES GCM 256 encryption.  It is
enabled by default and can be set to required with:

MODULE_PARM_DESC(require_gcm_256, "Require strongest (256 bit) GCM
encryption. Default: n/N/0");

On Tue, Feb 28, 2023 at 5:57 PM Namjae Jeon <linkinjeon@kernel.org> wrote:
>
> MacOS and Win11 support AES256 encrytion and it is included in the cipher
> array of encryption context. Especially on macOS, The most preferred
> cipher is AES256. Connecting to ksmbd fails on newer MacOS clients that
> support AES256 encryption. MacOS send disconnect request after receiving
> final session setup response from ksmbd. Because final session setup is
> signed with signing key was generated incorrectly.
> For signging key, 'L' value should be initialized to 128 if key size is
> 16bytes.
>
> Reported-by: Miao Lihua <441884205@qq.com>
> Tested-by: Miao Lihua <441884205@qq.com>
> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
> ---
>  fs/ksmbd/auth.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/fs/ksmbd/auth.c b/fs/ksmbd/auth.c
> index 6e61b5bc7d86..cead696b656a 100644
> --- a/fs/ksmbd/auth.c
> +++ b/fs/ksmbd/auth.c
> @@ -727,8 +727,9 @@ static int generate_key(struct ksmbd_conn *conn, struct ksmbd_session *sess,
>                 goto smb3signkey_ret;
>         }
>
> -       if (conn->cipher_type == SMB2_ENCRYPTION_AES256_CCM ||
> -           conn->cipher_type == SMB2_ENCRYPTION_AES256_GCM)
> +       if (key_size == SMB3_ENC_DEC_KEY_SIZE &&
> +           (conn->cipher_type == SMB2_ENCRYPTION_AES256_CCM ||
> +            conn->cipher_type == SMB2_ENCRYPTION_AES256_GCM))
>                 rc = crypto_shash_update(CRYPTO_HMACSHA256(ctx), L256, 4);
>         else
>                 rc = crypto_shash_update(CRYPTO_HMACSHA256(ctx), L128, 4);
> --
> 2.25.1
>


-- 
Thanks,

Steve