On Fri, 10 Dec 2010 10:30:47 -0600
shirishpargaonkar@xxxxxxxxx wrote:
> From: Shirish Pargaonkar <shirishpargaonkar@xxxxxxxxx>
>
>
> Indicate to the server a capability of NTLM2 session security (NTLM2 Key)
> during ntlmssp protocol exchange in one of the bits of the flags field.
> If server supports this capability, send NTLM2 key even if signing is not
> required on the server.
>
> If the server requires signing, the session keys exchanged for NTLMv2
> and NTLM2 session security in auth packet of the nlmssp exchange are same.
>
> Send the same flags in authenticate message (type 3) that client sent in
> negotiate message (type 1).
>
> Remove function setup_ntlmssp_neg_req() and allocate zero'ed buffers
> to prepare ntlmssp negotiate and authenticat requests.
>
>
> Reported-and-Tested-by: Robbert Kouprie <robbert@xxxxxx>
> Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@xxxxxxxxx>
> ---
> fs/cifs/sess.c | 46 +++++++++++++++++++++++++---------------------
> 1 files changed, 25 insertions(+), 21 deletions(-)
>
> diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c
> index 7b01d3f..56e945a 100644
> --- a/fs/cifs/sess.c
> +++ b/fs/cifs/sess.c
> @@ -425,7 +425,7 @@ static int decode_ntlmssp_challenge(char *bcc_ptr, int blob_len,
>
> /* We do not malloc the blob, it is passed in pbuffer, because
> it is fixed size, and small, making this approach cleaner */
> -static void build_ntlmssp_negotiate_blob(unsigned char *pbuffer,
> +static void build_ntlmssp_negotiate_blob(char *pbuffer,
> struct cifsSesInfo *ses)
> {
> NEGOTIATE_MESSAGE *sec_blob = (NEGOTIATE_MESSAGE *)pbuffer;
> @@ -437,7 +437,7 @@ static void build_ntlmssp_negotiate_blob(unsigned char *pbuffer,
> /* BB is NTLMV2 session security format easier to use here? */
> flags = NTLMSSP_NEGOTIATE_56 | NTLMSSP_REQUEST_TARGET |
> NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE |
> - NTLMSSP_NEGOTIATE_NTLM;
> + NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC;
> if (ses->server->secMode &
> (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED)) {
> flags |= NTLMSSP_NEGOTIATE_SIGN;
> @@ -446,7 +446,7 @@ static void build_ntlmssp_negotiate_blob(unsigned char *pbuffer,
> NTLMSSP_NEGOTIATE_EXTENDED_SEC;
> }
>
> - sec_blob->NegotiateFlags |= cpu_to_le32(flags);
> + sec_blob->NegotiateFlags = cpu_to_le32(flags);
>
> sec_blob->WorkstationName.BufferOffset = 0;
> sec_blob->WorkstationName.Length = 0;
> @@ -477,7 +477,7 @@ static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
> flags = NTLMSSP_NEGOTIATE_56 |
> NTLMSSP_REQUEST_TARGET | NTLMSSP_NEGOTIATE_TARGET_INFO |
> NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE |
> - NTLMSSP_NEGOTIATE_NTLM;
> + NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC;
> if (ses->server->secMode &
> (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
> flags |= NTLMSSP_NEGOTIATE_SIGN;
> @@ -485,7 +485,7 @@ static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
> flags |= NTLMSSP_NEGOTIATE_ALWAYS_SIGN;
>
> tmp = pbuffer + sizeof(AUTHENTICATE_MESSAGE);
> - sec_blob->NegotiateFlags |= cpu_to_le32(flags);
> + sec_blob->NegotiateFlags = cpu_to_le32(flags);
>
> sec_blob->LmChallengeResponse.BufferOffset =
> cpu_to_le32(sizeof(AUTHENTICATE_MESSAGE));
> @@ -544,8 +544,9 @@ static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
> sec_blob->WorkstationName.MaximumLength = 0;
> tmp += 2;
>
> - if ((ses->ntlmssp->server_flags & NTLMSSP_NEGOTIATE_KEY_XCH) &&
> - !calc_seckey(ses)) {
> + if (((ses->ntlmssp->server_flags & NTLMSSP_NEGOTIATE_KEY_XCH) ||
> + (ses->ntlmssp->server_flags & NTLMSSP_NEGOTIATE_EXTENDED_SEC))
> + && !calc_seckey(ses)) {
> memcpy(tmp, ses->ntlmssp->ciphertext, CIFS_CPHTXT_SIZE);
> sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - pbuffer);
> sec_blob->SessionKey.Length = cpu_to_le16(CIFS_CPHTXT_SIZE);
> @@ -562,16 +563,6 @@ setup_ntlmv2_ret:
> *buflen = tmp - pbuffer;
> return rc;
> }
> -
> -
> -static void setup_ntlmssp_neg_req(SESSION_SETUP_ANDX *pSMB,
> - struct cifsSesInfo *ses)
> -{
> - build_ntlmssp_negotiate_blob(&pSMB->req.SecurityBlob[0], ses);
> - pSMB->req.SecurityBlobLength = cpu_to_le16(sizeof(NEGOTIATE_MESSAGE));
> -
> - return;
> -}
^^^^^
I like that you removed the above function. It was useless indirection.
> #endif
>
> int
> @@ -595,6 +586,7 @@ CIFS_SessSetup(unsigned int xid, struct cifsSesInfo *ses,
> __le32 phase = NtLmNegotiate; /* NTLMSSP, if needed, is multistage */
> u16 blob_len;
> char *ntlmsspblob = NULL;
> + char *ntlmsspnblob = NULL;
>
> if (ses == NULL)
> return -EINVAL;
> @@ -828,16 +820,26 @@ ssetup_ntlmssp_authenticate:
> capabilities |= CAP_EXTENDED_SECURITY;
> pSMB->req.Capabilities |= cpu_to_le32(capabilities);
> if (phase == NtLmNegotiate) {
> - setup_ntlmssp_neg_req(pSMB, ses);
> + ntlmsspnblob = kzalloc(
> + sizeof(struct _NEGOTIATE_MESSAGE),
> + GFP_KERNEL);
> + if (!ntlmsspnblob) {
> + cERROR(1, "Can't allocate NTLMSSPN");
> + rc = -ENOMEM;
> + goto ssetup_exit;
> + }
> + build_ntlmssp_negotiate_blob(ntlmsspnblob, ses);
Why did you decide to allocate a new buffer here? Was the SecurityBlob
not big enough? If not, then I think it would make more sense to just
memset the existing buffer to 0.
> iov[1].iov_len = sizeof(NEGOTIATE_MESSAGE);
> - iov[1].iov_base = &pSMB->req.SecurityBlob[0];
> + iov[1].iov_base = ntlmsspnblob;
> + pSMB->req.SecurityBlobLength =
> + cpu_to_le16(sizeof(NEGOTIATE_MESSAGE));
> } else if (phase == NtLmAuthenticate) {
> - /* 5 is an empirical value, large enought to
> + /* 5 is an empirical value, large enough to
> * hold authenticate message, max 10 of
> * av paris, doamin,user,workstation mames,
> * flags etc..
> */
> - ntlmsspblob = kmalloc(
> + ntlmsspblob = kzalloc(
> 5*sizeof(struct _AUTHENTICATE_MESSAGE),
> GFP_KERNEL);
> if (!ntlmsspblob) {
> @@ -960,6 +962,8 @@ ssetup_exit:
> key_put(spnego_key);
> }
> kfree(str_area);
> + kfree(ntlmsspnblob);
> + ntlmsspnblob = NULL;
If we did decide that we needed a new buffer for this, I don't think we
need a new pointer on the stack for it. ntlmsspblob would suffice in
that case.
> kfree(ntlmsspblob);
> ntlmsspblob = NULL;
> if (resp_buf_type == CIFS_SMALL_BUFFER) {
--
Jeff Layton <jlayton@xxxxxxxxx>
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