Exemplo n.º 1
0
static void
sess_auth_rawntlmssp_negotiate(struct sess_data *sess_data)
{
	int rc;
	struct smb_hdr *smb_buf;
	SESSION_SETUP_ANDX *pSMB;
	struct cifs_ses *ses = sess_data->ses;
	__u16 bytes_remaining;
	char *bcc_ptr;
	u16 blob_len;

	cifs_dbg(FYI, "rawntlmssp session setup negotiate phase\n");

	/*
	 * if memory allocation is successful, caller of this function
	 * frees it.
	 */
	ses->ntlmssp = kmalloc(sizeof(struct ntlmssp_auth), GFP_KERNEL);
	if (!ses->ntlmssp) {
		rc = -ENOMEM;
		goto out;
	}
	ses->ntlmssp->sesskey_per_smbsess = false;

	/* wct = 12 */
	rc = sess_alloc_buffer(sess_data, 12);
	if (rc)
		goto out;

	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;

	/* Build security blob before we assemble the request */
	build_ntlmssp_negotiate_blob(pSMB->req.SecurityBlob, ses);
	sess_data->iov[1].iov_len = sizeof(NEGOTIATE_MESSAGE);
	sess_data->iov[1].iov_base = pSMB->req.SecurityBlob;
	pSMB->req.SecurityBlobLength = cpu_to_le16(sizeof(NEGOTIATE_MESSAGE));

	rc = _sess_auth_rawntlmssp_assemble_req(sess_data);
	if (rc)
		goto out;

	rc = sess_sendreceive(sess_data);

	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
	smb_buf = (struct smb_hdr *)sess_data->iov[0].iov_base;

	/* If true, rc here is expected and not an error */
	if (sess_data->buf0_type != CIFS_NO_BUFFER &&
	    smb_buf->Status.CifsError ==
			cpu_to_le32(NT_STATUS_MORE_PROCESSING_REQUIRED))
		rc = 0;

	if (rc)
		goto out;

	cifs_dbg(FYI, "rawntlmssp session setup challenge phase\n");

	if (smb_buf->WordCount != 4) {
		rc = -EIO;
		cifs_dbg(VFS, "bad word count %d\n", smb_buf->WordCount);
		goto out;
	}

	ses->Suid = smb_buf->Uid;   /* UID left in wire format (le) */
	cifs_dbg(FYI, "UID = %llu\n", ses->Suid);

	bytes_remaining = get_bcc(smb_buf);
	bcc_ptr = pByteArea(smb_buf);

	blob_len = le16_to_cpu(pSMB->resp.SecurityBlobLength);
	if (blob_len > bytes_remaining) {
		cifs_dbg(VFS, "bad security blob length %d\n",
				blob_len);
		rc = -EINVAL;
		goto out;
	}

	rc = decode_ntlmssp_challenge(bcc_ptr, blob_len, ses);
out:
	sess_free_buffer(sess_data);

	if (!rc) {
		sess_data->func = sess_auth_rawntlmssp_authenticate;
		return;
	}

	/* Else error. Cleanup */
	kfree(ses->auth_key.response);
	ses->auth_key.response = NULL;
	kfree(ses->ntlmssp);
	ses->ntlmssp = NULL;

	sess_data->func = NULL;
	sess_data->result = rc;
}
Exemplo n.º 2
0
Arquivo: sess.c Projeto: 7799/linux
int
CIFS_SessSetup(const unsigned int xid, struct cifs_ses *ses,
	       const struct nls_table *nls_cp)
{
	int rc = 0;
	int wct;
	struct smb_hdr *smb_buf;
	char *bcc_ptr;
	char *str_area;
	SESSION_SETUP_ANDX *pSMB;
	__u32 capabilities;
	__u16 count;
	int resp_buf_type;
	struct kvec iov[3];
	enum securityEnum type;
	__u16 action, bytes_remaining;
	struct key *spnego_key = NULL;
	__le32 phase = NtLmNegotiate; /* NTLMSSP, if needed, is multistage */
	u16 blob_len;
	char *ntlmsspblob = NULL;

	if (ses == NULL) {
		WARN(1, "%s: ses == NULL!", __func__);
		return -EINVAL;
	}

	type = select_sectype(ses->server, ses->sectype);
	cifs_dbg(FYI, "sess setup type %d\n", type);
	if (type == Unspecified) {
		cifs_dbg(VFS,
			"Unable to select appropriate authentication method!");
		return -EINVAL;
	}

	if (type == RawNTLMSSP) {
		/* if memory allocation is successful, caller of this function
		 * frees it.
		 */
		ses->ntlmssp = kmalloc(sizeof(struct ntlmssp_auth), GFP_KERNEL);
		if (!ses->ntlmssp)
			return -ENOMEM;
		ses->ntlmssp->sesskey_per_smbsess = false;

	}

ssetup_ntlmssp_authenticate:
	if (phase == NtLmChallenge)
		phase = NtLmAuthenticate; /* if ntlmssp, now final phase */

	if (type == LANMAN) {
#ifndef CONFIG_CIFS_WEAK_PW_HASH
		/* LANMAN and plaintext are less secure and off by default.
		So we make this explicitly be turned on in kconfig (in the
		build) and turned on at runtime (changed from the default)
		in proc/fs/cifs or via mount parm.  Unfortunately this is
		needed for old Win (e.g. Win95), some obscure NAS and OS/2 */
		return -EOPNOTSUPP;
#endif
		wct = 10; /* lanman 2 style sessionsetup */
	} else if ((type == NTLM) || (type == NTLMv2)) {
		/* For NTLMv2 failures eventually may need to retry NTLM */
		wct = 13; /* old style NTLM sessionsetup */
	} else /* same size: negotiate or auth, NTLMSSP or extended security */
		wct = 12;

	rc = small_smb_init_no_tc(SMB_COM_SESSION_SETUP_ANDX, wct, ses,
			    (void **)&smb_buf);
	if (rc)
		return rc;

	pSMB = (SESSION_SETUP_ANDX *)smb_buf;

	capabilities = cifs_ssetup_hdr(ses, pSMB);

	/* we will send the SMB in three pieces:
	a fixed length beginning part, an optional
	SPNEGO blob (which can be zero length), and a
	last part which will include the strings
	and rest of bcc area. This allows us to avoid
	a large buffer 17K allocation */
	iov[0].iov_base = (char *)pSMB;
	iov[0].iov_len = be32_to_cpu(smb_buf->smb_buf_length) + 4;

	/* setting this here allows the code at the end of the function
	   to free the request buffer if there's an error */
	resp_buf_type = CIFS_SMALL_BUFFER;

	/* 2000 big enough to fit max user, domain, NOS name etc. */
	str_area = kmalloc(2000, GFP_KERNEL);
	if (str_area == NULL) {
		rc = -ENOMEM;
		goto ssetup_exit;
	}
	bcc_ptr = str_area;

	iov[1].iov_base = NULL;
	iov[1].iov_len = 0;

	if (type == LANMAN) {
#ifdef CONFIG_CIFS_WEAK_PW_HASH
		char lnm_session_key[CIFS_AUTH_RESP_SIZE];

		pSMB->req.hdr.Flags2 &= ~SMBFLG2_UNICODE;

		/* no capabilities flags in old lanman negotiation */

		pSMB->old_req.PasswordLength = cpu_to_le16(CIFS_AUTH_RESP_SIZE);

		/* Calculate hash with password and copy into bcc_ptr.
		 * Encryption Key (stored as in cryptkey) gets used if the
		 * security mode bit in Negottiate Protocol response states
		 * to use challenge/response method (i.e. Password bit is 1).
		 */

		rc = calc_lanman_hash(ses->password, ses->server->cryptkey,
				 ses->server->sec_mode & SECMODE_PW_ENCRYPT ?
					true : false, lnm_session_key);

		memcpy(bcc_ptr, (char *)lnm_session_key, CIFS_AUTH_RESP_SIZE);
		bcc_ptr += CIFS_AUTH_RESP_SIZE;

		/* can not sign if LANMAN negotiated so no need
		to calculate signing key? but what if server
		changed to do higher than lanman dialect and
		we reconnected would we ever calc signing_key? */

		cifs_dbg(FYI, "Negotiating LANMAN setting up strings\n");
		/* Unicode not allowed for LANMAN dialects */
		ascii_ssetup_strings(&bcc_ptr, ses, nls_cp);
#endif
	} else if (type == NTLM) {
		pSMB->req_no_secext.Capabilities = cpu_to_le32(capabilities);
		pSMB->req_no_secext.CaseInsensitivePasswordLength =
			cpu_to_le16(CIFS_AUTH_RESP_SIZE);
		pSMB->req_no_secext.CaseSensitivePasswordLength =
			cpu_to_le16(CIFS_AUTH_RESP_SIZE);

		/* calculate ntlm response and session key */
		rc = setup_ntlm_response(ses, nls_cp);
		if (rc) {
			cifs_dbg(VFS, "Error %d during NTLM authentication\n",
				 rc);
			goto ssetup_exit;
		}

		/* copy ntlm response */
		memcpy(bcc_ptr, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
				CIFS_AUTH_RESP_SIZE);
		bcc_ptr += CIFS_AUTH_RESP_SIZE;
		memcpy(bcc_ptr, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
				CIFS_AUTH_RESP_SIZE);
		bcc_ptr += CIFS_AUTH_RESP_SIZE;

		if (ses->capabilities & CAP_UNICODE) {
			/* unicode strings must be word aligned */
			if (iov[0].iov_len % 2) {
				*bcc_ptr = 0;
				bcc_ptr++;
			}
			unicode_ssetup_strings(&bcc_ptr, ses, nls_cp);
		} else
			ascii_ssetup_strings(&bcc_ptr, ses, nls_cp);
	} else if (type == NTLMv2) {
		pSMB->req_no_secext.Capabilities = cpu_to_le32(capabilities);

		/* LM2 password would be here if we supported it */
		pSMB->req_no_secext.CaseInsensitivePasswordLength = 0;

		/* calculate nlmv2 response and session key */
		rc = setup_ntlmv2_rsp(ses, nls_cp);
		if (rc) {
			cifs_dbg(VFS, "Error %d during NTLMv2 authentication\n",
				 rc);
			goto ssetup_exit;
		}
		memcpy(bcc_ptr, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
				ses->auth_key.len - CIFS_SESS_KEY_SIZE);
		bcc_ptr += ses->auth_key.len - CIFS_SESS_KEY_SIZE;

		/* set case sensitive password length after tilen may get
		 * assigned, tilen is 0 otherwise.
		 */
		pSMB->req_no_secext.CaseSensitivePasswordLength =
			cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);

		if (ses->capabilities & CAP_UNICODE) {
			if (iov[0].iov_len % 2) {
				*bcc_ptr = 0;
				bcc_ptr++;
			}
			unicode_ssetup_strings(&bcc_ptr, ses, nls_cp);
		} else
			ascii_ssetup_strings(&bcc_ptr, ses, nls_cp);
	} else if (type == Kerberos) {
#ifdef CONFIG_CIFS_UPCALL
		struct cifs_spnego_msg *msg;

		spnego_key = cifs_get_spnego_key(ses);
		if (IS_ERR(spnego_key)) {
			rc = PTR_ERR(spnego_key);
			spnego_key = NULL;
			goto ssetup_exit;
		}

		msg = spnego_key->payload.data;
		/* check version field to make sure that cifs.upcall is
		   sending us a response in an expected form */
		if (msg->version != CIFS_SPNEGO_UPCALL_VERSION) {
			cifs_dbg(VFS, "incorrect version of cifs.upcall "
				   "expected %d but got %d)",
				   CIFS_SPNEGO_UPCALL_VERSION, msg->version);
			rc = -EKEYREJECTED;
			goto ssetup_exit;
		}

		ses->auth_key.response = kmemdup(msg->data, msg->sesskey_len,
						 GFP_KERNEL);
		if (!ses->auth_key.response) {
			cifs_dbg(VFS,
				"Kerberos can't allocate (%u bytes) memory",
				msg->sesskey_len);
			rc = -ENOMEM;
			goto ssetup_exit;
		}
		ses->auth_key.len = msg->sesskey_len;

		pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC;
		capabilities |= CAP_EXTENDED_SECURITY;
		pSMB->req.Capabilities = cpu_to_le32(capabilities);
		iov[1].iov_base = msg->data + msg->sesskey_len;
		iov[1].iov_len = msg->secblob_len;
		pSMB->req.SecurityBlobLength = cpu_to_le16(iov[1].iov_len);

		if (ses->capabilities & CAP_UNICODE) {
			/* unicode strings must be word aligned */
			if ((iov[0].iov_len + iov[1].iov_len) % 2) {
				*bcc_ptr = 0;
				bcc_ptr++;
			}
			unicode_oslm_strings(&bcc_ptr, nls_cp);
			unicode_domain_string(&bcc_ptr, ses, nls_cp);
		} else
		/* BB: is this right? */
			ascii_ssetup_strings(&bcc_ptr, ses, nls_cp);
#else /* ! CONFIG_CIFS_UPCALL */
		cifs_dbg(VFS, "Kerberos negotiated but upcall support disabled!\n");
		rc = -ENOSYS;
		goto ssetup_exit;
#endif /* CONFIG_CIFS_UPCALL */
	} else if (type == RawNTLMSSP) {
		if ((pSMB->req.hdr.Flags2 & SMBFLG2_UNICODE) == 0) {
			cifs_dbg(VFS, "NTLMSSP requires Unicode support\n");
			rc = -ENOSYS;
			goto ssetup_exit;
		}

		cifs_dbg(FYI, "ntlmssp session setup phase %d\n", phase);
		pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC;
		capabilities |= CAP_EXTENDED_SECURITY;
		pSMB->req.Capabilities |= cpu_to_le32(capabilities);
		switch(phase) {
		case NtLmNegotiate:
			build_ntlmssp_negotiate_blob(
				pSMB->req.SecurityBlob, ses);
			iov[1].iov_len = sizeof(NEGOTIATE_MESSAGE);
			iov[1].iov_base = pSMB->req.SecurityBlob;
			pSMB->req.SecurityBlobLength =
				cpu_to_le16(sizeof(NEGOTIATE_MESSAGE));
			break;
		case NtLmAuthenticate:
			/*
			 * 5 is an empirical value, large enough to hold
			 * authenticate message plus max 10 of av paris,
			 * domain, user, workstation names, flags, etc.
			 */
			ntlmsspblob = kzalloc(
				5*sizeof(struct _AUTHENTICATE_MESSAGE),
				GFP_KERNEL);
			if (!ntlmsspblob) {
				rc = -ENOMEM;
				goto ssetup_exit;
			}

			rc = build_ntlmssp_auth_blob(ntlmsspblob,
						&blob_len, ses, nls_cp);
			if (rc)
				goto ssetup_exit;
			iov[1].iov_len = blob_len;
			iov[1].iov_base = ntlmsspblob;
			pSMB->req.SecurityBlobLength = cpu_to_le16(blob_len);
			/*
			 * Make sure that we tell the server that we are using
			 * the uid that it just gave us back on the response
			 * (challenge)
			 */
			smb_buf->Uid = ses->Suid;
			break;
		default:
			cifs_dbg(VFS, "invalid phase %d\n", phase);
			rc = -ENOSYS;
			goto ssetup_exit;
		}
		/* unicode strings must be word aligned */
		if ((iov[0].iov_len + iov[1].iov_len) % 2) {
			*bcc_ptr = 0;
			bcc_ptr++;
		}
		unicode_oslm_strings(&bcc_ptr, nls_cp);
	} else {
		cifs_dbg(VFS, "secType %d not supported!\n", type);
		rc = -ENOSYS;
		goto ssetup_exit;
	}

	iov[2].iov_base = str_area;
	iov[2].iov_len = (long) bcc_ptr - (long) str_area;

	count = iov[1].iov_len + iov[2].iov_len;
	smb_buf->smb_buf_length =
		cpu_to_be32(be32_to_cpu(smb_buf->smb_buf_length) + count);

	put_bcc(count, smb_buf);

	rc = SendReceive2(xid, ses, iov, 3 /* num_iovecs */, &resp_buf_type,
			  CIFS_LOG_ERROR);
	/* SMB request buf freed in SendReceive2 */

	pSMB = (SESSION_SETUP_ANDX *)iov[0].iov_base;
	smb_buf = (struct smb_hdr *)iov[0].iov_base;

	if ((type == RawNTLMSSP) && (resp_buf_type != CIFS_NO_BUFFER) &&
	    (smb_buf->Status.CifsError ==
			cpu_to_le32(NT_STATUS_MORE_PROCESSING_REQUIRED))) {
		if (phase != NtLmNegotiate) {
			cifs_dbg(VFS, "Unexpected more processing error\n");
			goto ssetup_exit;
		}
		/* NTLMSSP Negotiate sent now processing challenge (response) */
		phase = NtLmChallenge; /* process ntlmssp challenge */
		rc = 0; /* MORE_PROC rc is not an error here, but expected */
	}
	if (rc)
		goto ssetup_exit;

	if ((smb_buf->WordCount != 3) && (smb_buf->WordCount != 4)) {
		rc = -EIO;
		cifs_dbg(VFS, "bad word count %d\n", smb_buf->WordCount);
		goto ssetup_exit;
	}
	action = le16_to_cpu(pSMB->resp.Action);
	if (action & GUEST_LOGIN)
		cifs_dbg(FYI, "Guest login\n"); /* BB mark SesInfo struct? */
	ses->Suid = smb_buf->Uid;   /* UID left in wire format (le) */
	cifs_dbg(FYI, "UID = %llu\n", ses->Suid);
	/* response can have either 3 or 4 word count - Samba sends 3 */
	/* and lanman response is 3 */
	bytes_remaining = get_bcc(smb_buf);
	bcc_ptr = pByteArea(smb_buf);

	if (smb_buf->WordCount == 4) {
		blob_len = le16_to_cpu(pSMB->resp.SecurityBlobLength);
		if (blob_len > bytes_remaining) {
			cifs_dbg(VFS, "bad security blob length %d\n",
				 blob_len);
			rc = -EINVAL;
			goto ssetup_exit;
		}
		if (phase == NtLmChallenge) {
			rc = decode_ntlmssp_challenge(bcc_ptr, blob_len, ses);
			/* now goto beginning for ntlmssp authenticate phase */
			if (rc)
				goto ssetup_exit;
		}
		bcc_ptr += blob_len;
		bytes_remaining -= blob_len;
	}

	/* BB check if Unicode and decode strings */
	if (bytes_remaining == 0) {
		/* no string area to decode, do nothing */
	} else if (smb_buf->Flags2 & SMBFLG2_UNICODE) {
		/* unicode string area must be word-aligned */
		if (((unsigned long) bcc_ptr - (unsigned long) smb_buf) % 2) {
			++bcc_ptr;
			--bytes_remaining;
		}
		decode_unicode_ssetup(&bcc_ptr, bytes_remaining, ses, nls_cp);
	} else {
		decode_ascii_ssetup(&bcc_ptr, bytes_remaining, ses, nls_cp);
	}

ssetup_exit:
	if (spnego_key) {
		key_invalidate(spnego_key);
		key_put(spnego_key);
	}
	kfree(str_area);
	kfree(ntlmsspblob);
	ntlmsspblob = NULL;
	if (resp_buf_type == CIFS_SMALL_BUFFER) {
		cifs_dbg(FYI, "ssetup freeing small buf %p\n", iov[0].iov_base);
		cifs_small_buf_release(iov[0].iov_base);
	} else if (resp_buf_type == CIFS_LARGE_BUFFER)
		cifs_buf_release(iov[0].iov_base);

	/* if ntlmssp, and negotiate succeeded, proceed to authenticate phase */
	if ((phase == NtLmChallenge) && (rc == 0))
		goto ssetup_ntlmssp_authenticate;

	if (!rc) {
		mutex_lock(&ses->server->srv_mutex);
		if (!ses->server->session_estab) {
			if (ses->server->sign) {
				ses->server->session_key.response =
					kmemdup(ses->auth_key.response,
					ses->auth_key.len, GFP_KERNEL);
				if (!ses->server->session_key.response) {
					rc = -ENOMEM;
					mutex_unlock(&ses->server->srv_mutex);
					goto keycp_exit;
				}
				ses->server->session_key.len =
							ses->auth_key.len;
			}
			ses->server->sequence_number = 0x2;
			ses->server->session_estab = true;
		}
		mutex_unlock(&ses->server->srv_mutex);

		cifs_dbg(FYI, "CIFS session established successfully\n");
		spin_lock(&GlobalMid_Lock);
		ses->status = CifsGood;
		ses->need_reconnect = false;
		spin_unlock(&GlobalMid_Lock);
	}

keycp_exit:
	kfree(ses->auth_key.response);
	ses->auth_key.response = NULL;
	kfree(ses->ntlmssp);

	return rc;
}