On Thu, 29 Aug 2013 08:35:10 -0500
Shirish Pargaonkar <shirishpargaonkar@xxxxxxxxx> wrote:
> Add a variable specific to NTLMSSP authentication to determine
> whether to exchange keys during negotiation and authentication phases.
>
> Since session key for smb1 is per smb connection, once a very first
> sesion is established, there is no need for key exchange during
> subsequent session setups. As a result, smb1 session setup code sets this
> variable as false.
>
> Since session key for smb2 and smb3 is per smb connection, we need to
> exchange keys to generate session key for every sesion being established.
> As a result, smb2/3 session setup code sets this variable as true.
> ---
> fs/cifs/cifsglob.h | 1 +
> fs/cifs/sess.c | 8 ++++++--
> fs/cifs/smb2pdu.c | 1 +
> 3 files changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
> index 52ca861..cce26a8 100644
> --- a/fs/cifs/cifsglob.h
> +++ b/fs/cifs/cifsglob.h
> @@ -135,6 +135,7 @@ struct cifs_secmech {
>
> /* per smb session structure/fields */
> struct ntlmssp_auth {
> + bool sesskey_per_smbsess; /* whether session key is per smb session */
> __u32 client_flags; /* sent by client in type 1 ntlmsssp exchange */
> __u32 server_flags; /* sent by server in type 2 ntlmssp exchange */
> unsigned char ciphertext[CIFS_CPHTXT_SIZE]; /* sent to server */
> diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c
> index 7afd54a..d7907c4 100644
> --- a/fs/cifs/sess.c
> +++ b/fs/cifs/sess.c
> @@ -428,7 +428,8 @@ void build_ntlmssp_negotiate_blob(unsigned char *pbuffer,
> NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC;
> if (ses->server->sign) {
> flags |= NTLMSSP_NEGOTIATE_SIGN;
> - if (!ses->server->session_estab)
> + if (!ses->server->session_estab ||
> + ses->ntlmssp->sesskey_per_smbsess)
> flags |= NTLMSSP_NEGOTIATE_KEY_XCH;
> }
>
> @@ -466,7 +467,8 @@ int build_ntlmssp_auth_blob(unsigned char *pbuffer,
> NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC;
> if (ses->server->sign) {
> flags |= NTLMSSP_NEGOTIATE_SIGN;
> - if (!ses->server->session_estab)
> + if (!ses->server->session_estab ||
> + ses->ntlmssp->sesskey_per_smbsess)
> flags |= NTLMSSP_NEGOTIATE_KEY_XCH;
> }
>
> @@ -641,6 +643,8 @@ CIFS_SessSetup(const unsigned int xid, struct cifs_ses *ses,
> ses->ntlmssp = kmalloc(sizeof(struct ntlmssp_auth), GFP_KERNEL);
> if (!ses->ntlmssp)
> return -ENOMEM;
> + ses->ntlmssp->sesskey_per_smbsess = false;
> +
> }
>
> ssetup_ntlmssp_authenticate:
> diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
> index 05a0186..28083b4 100644
> --- a/fs/cifs/smb2pdu.c
> +++ b/fs/cifs/smb2pdu.c
> @@ -491,6 +491,7 @@ SMB2_sess_setup(const unsigned int xid, struct cifs_ses *ses,
> ses->ntlmssp = kmalloc(sizeof(struct ntlmssp_auth), GFP_KERNEL);
> if (!ses->ntlmssp)
> return -ENOMEM;
> + ses->ntlmssp->sesskey_per_smbsess = true;
>
> /* FIXME: allow for other auth types besides NTLMSSP (e.g. krb5) */
> ses->sectype = RawNTLMSSP;
Acked-by: Jeff Layton <jlayton@xxxxxxxxx>
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