On Fri, 10 Dec 2010 15:43:17 -0600
Shirish Pargaonkar <shirishpargaonkar@xxxxxxxxx> wrote:
> On Fri, Dec 10, 2010 at 3:13 PM, Jeff Layton <jlayton@xxxxxxxxx> wrote:
> > 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.
>
> No the buffer allocated by small_smb_init is sufficient to hold the
> ntlmssp negotiate request. I do not need to allocate a new buffer.
> And header_assemble memsets that buffer to 0, so no need to redo it again.
>
> So only ntlmsspblob needs to be kzalloc'ed.
>
header_assemble does this:
memset(temp, 0, 256); /* bigger than MAX_CIFS_HDR_SIZE */
...is that enough? (I haven't measured it).
> >
> >> 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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--
Jeff Layton <jlayton@xxxxxxxxx>
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