source: branches/samba-3.5.x/source4/smb_server/smb/sesssetup.c

/* 
   Unix SMB/CIFS implementation.
   handle SMBsessionsetup
   Copyright (C) Andrew Tridgell                      1998-2001
   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2001-2005
   Copyright (C) Jim McDonough                        2002
   Copyright (C) Luke Howard                          2003
   Copyright (C) Stefan Metzmacher                    2005
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"
#include "version.h"
#include "auth/gensec/gensec.h"
#include "auth/auth.h"
#include "smb_server/smb_server.h"
#include "smbd/service_stream.h"
#include "param/param.h"

/*
  setup the OS, Lanman and domain portions of a session setup reply
*/
static void sesssetup_common_strings(struct smbsrv_request *req,
                                     char **os, char **lanman, char **domain)
{
        (*os) = talloc_asprintf(req, "Unix");
        (*lanman) = talloc_asprintf(req, "Samba %s", SAMBA_VERSION_STRING);
        (*domain) = talloc_asprintf(req, "%s", 
                                    lp_workgroup(req->smb_conn->lp_ctx));
}

static void smbsrv_sesssetup_backend_send(struct smbsrv_request *req,
                                          union smb_sesssetup *sess,
                                          NTSTATUS status)
{
        if (NT_STATUS_IS_OK(status)) {
                req->smb_conn->negotiate.done_sesssetup = true;
                /* we need to keep the session long term */
                req->session = talloc_steal(req->smb_conn, req->session);
        }
        smbsrv_reply_sesssetup_send(req, sess, status);
}

static void sesssetup_old_send(struct auth_check_password_request *areq,
                               void *private_data)
{
        struct smbsrv_request *req = talloc_get_type(private_data, struct smbsrv_request);
        union smb_sesssetup *sess = talloc_get_type(req->io_ptr, union smb_sesssetup);
        struct auth_serversupplied_info *server_info = NULL;
        struct auth_session_info *session_info;
        struct smbsrv_session *smb_sess;
        NTSTATUS status;

        status = auth_check_password_recv(areq, req, &server_info);
        if (!NT_STATUS_IS_OK(status)) goto failed;

        /* This references server_info into session_info */
        status = auth_generate_session_info(req, req->smb_conn->connection->event.ctx, req->smb_conn->lp_ctx, 
                                            server_info, &session_info);
        if (!NT_STATUS_IS_OK(status)) goto failed;

        /* allocate a new session */
        smb_sess = smbsrv_session_new(req->smb_conn, req, NULL);
        if (!smb_sess) {
                status = NT_STATUS_INSUFFICIENT_RESOURCES;
                goto failed;
        }

        /* Ensure this is marked as a 'real' vuid, not one
         * simply valid for the session setup leg */
        status = smbsrv_session_sesssetup_finished(smb_sess, session_info);
        if (!NT_STATUS_IS_OK(status)) goto failed;

        /* To correctly process any AndX packet (like a tree connect)
         * we need to fill in the session on the request here */
        req->session = smb_sess;
        sess->old.out.vuid = smb_sess->vuid;

failed:
        status = auth_nt_status_squash(status);
        smbsrv_sesssetup_backend_send(req, sess, status);
}

/*
  handler for old style session setup
*/
static void sesssetup_old(struct smbsrv_request *req, union smb_sesssetup *sess)
{
        struct auth_usersupplied_info *user_info = NULL;
        struct socket_address *remote_address;
        const char *remote_machine = NULL;

        sess->old.out.vuid = 0;
        sess->old.out.action = 0;

        sesssetup_common_strings(req, 
                                 &sess->old.out.os,
                                 &sess->old.out.lanman,
                                 &sess->old.out.domain);

        if (!req->smb_conn->negotiate.done_sesssetup) {
                req->smb_conn->negotiate.max_send = sess->old.in.bufsize;
        }

        if (req->smb_conn->negotiate.calling_name) {
                remote_machine = req->smb_conn->negotiate.calling_name->name;
        }
        
        remote_address = socket_get_peer_addr(req->smb_conn->connection->socket, req);
        if (!remote_address) goto nomem;

        if (!remote_machine) {
                remote_machine = remote_address->addr;
        }

        user_info = talloc(req, struct auth_usersupplied_info);
        if (!user_info) goto nomem;
        
        user_info->mapped_state = false;
        user_info->logon_parameters = 0;
        user_info->flags = 0;
        user_info->client.account_name = sess->old.in.user;
        user_info->client.domain_name = sess->old.in.domain;
        user_info->workstation_name = remote_machine;
        user_info->remote_host = talloc_steal(user_info, remote_address);
        
        user_info->password_state = AUTH_PASSWORD_RESPONSE;
        user_info->password.response.lanman = sess->old.in.password;
        user_info->password.response.lanman.data = talloc_steal(user_info, sess->old.in.password.data);
        user_info->password.response.nt = data_blob(NULL, 0);

        auth_check_password_send(req->smb_conn->negotiate.auth_context, user_info,
                                 sesssetup_old_send, req);
        return;

nomem:
        smbsrv_sesssetup_backend_send(req, sess, NT_STATUS_NO_MEMORY);
}

static void sesssetup_nt1_send(struct auth_check_password_request *areq,
                               void *private_data)
{
        struct smbsrv_request *req = talloc_get_type(private_data, struct smbsrv_request);
        union smb_sesssetup *sess = talloc_get_type(req->io_ptr, union smb_sesssetup);
        struct auth_serversupplied_info *server_info = NULL;
        struct auth_session_info *session_info;
        struct smbsrv_session *smb_sess;
        NTSTATUS status;

        status = auth_check_password_recv(areq, req, &server_info);
        if (!NT_STATUS_IS_OK(status)) goto failed;

        /* This references server_info into session_info */
        status = auth_generate_session_info(req, req->smb_conn->connection->event.ctx, 
                                            req->smb_conn->lp_ctx, 
                                            server_info, &session_info);
        if (!NT_STATUS_IS_OK(status)) goto failed;

        /* allocate a new session */
        smb_sess = smbsrv_session_new(req->smb_conn, req, NULL);
        if (!smb_sess) {
                status = NT_STATUS_INSUFFICIENT_RESOURCES;
                goto failed;
        }

        /* Ensure this is marked as a 'real' vuid, not one
         * simply valid for the session setup leg */
        status = smbsrv_session_sesssetup_finished(smb_sess, session_info);
        if (!NT_STATUS_IS_OK(status)) goto failed;

        /* To correctly process any AndX packet (like a tree connect)
         * we need to fill in the session on the request here */
        req->session = smb_sess;
        sess->nt1.out.vuid = smb_sess->vuid;

        if (!smbsrv_setup_signing(req->smb_conn, &session_info->session_key, &sess->nt1.in.password2)) {
                /* Already signing, or disabled */
                goto done;
        }

done:
        status = NT_STATUS_OK;
failed:
        status = auth_nt_status_squash(status);
        smbsrv_sesssetup_backend_send(req, sess, status);
}

/*
  handler for NT1 style session setup
*/
static void sesssetup_nt1(struct smbsrv_request *req, union smb_sesssetup *sess)
{
        NTSTATUS status;
        struct auth_context *auth_context;
        struct auth_usersupplied_info *user_info = NULL;
        struct socket_address *remote_address;
        const char *remote_machine = NULL;
        
        sess->nt1.out.vuid = 0;
        sess->nt1.out.action = 0;

        sesssetup_common_strings(req, 
                                 &sess->nt1.out.os,
                                 &sess->nt1.out.lanman,
                                 &sess->nt1.out.domain);

        if (!req->smb_conn->negotiate.done_sesssetup) {
                req->smb_conn->negotiate.max_send = sess->nt1.in.bufsize;
                req->smb_conn->negotiate.client_caps = sess->nt1.in.capabilities;
        }

        if (req->smb_conn->negotiate.oid) {
                if (sess->nt1.in.user && *sess->nt1.in.user) {
                        /* We can't accept a normal login, because we
                         * don't have a challenge */
                        status = NT_STATUS_LOGON_FAILURE;
                        goto failed;
                }

                /* TODO: should we use just "anonymous" here? */
                status = auth_context_create(req, 
                                             req->smb_conn->connection->event.ctx,
                                             req->smb_conn->connection->msg_ctx,
                                             req->smb_conn->lp_ctx,
                                             &auth_context);
                if (!NT_STATUS_IS_OK(status)) goto failed;
        } else {
                auth_context = req->smb_conn->negotiate.auth_context;
        }

        if (req->smb_conn->negotiate.calling_name) {
                remote_machine = req->smb_conn->negotiate.calling_name->name;
        }

        remote_address = socket_get_peer_addr(req->smb_conn->connection->socket, req);
        if (!remote_address) goto nomem;

        if (!remote_machine) {
                remote_machine = remote_address->addr;
        }

        user_info = talloc(req, struct auth_usersupplied_info);
        if (!user_info) goto nomem;

        user_info->mapped_state = false;
        user_info->logon_parameters = 0;
        user_info->flags = 0;
        user_info->client.account_name = sess->nt1.in.user;
        user_info->client.domain_name = sess->nt1.in.domain;
        user_info->workstation_name = remote_machine;
        user_info->remote_host = talloc_steal(user_info, remote_address);
        
        user_info->password_state = AUTH_PASSWORD_RESPONSE;
        user_info->password.response.lanman = sess->nt1.in.password1;
        user_info->password.response.lanman.data = talloc_steal(user_info, sess->nt1.in.password1.data);
        user_info->password.response.nt = sess->nt1.in.password2;
        user_info->password.response.nt.data = talloc_steal(user_info, sess->nt1.in.password2.data);

        auth_check_password_send(auth_context, user_info,
                                 sesssetup_nt1_send, req);
        return;

nomem:
        status = NT_STATUS_NO_MEMORY;
failed:
        status = auth_nt_status_squash(status);
        smbsrv_sesssetup_backend_send(req, sess, status);
}

struct sesssetup_spnego_state {
        struct smbsrv_request *req;
        union smb_sesssetup *sess;
        struct smbsrv_session *smb_sess;
};

static void sesssetup_spnego_send(struct gensec_update_request *greq, void *private_data)
{
        struct sesssetup_spnego_state *s = talloc_get_type(private_data,
                                           struct sesssetup_spnego_state);
        struct smbsrv_request *req = s->req;
        union smb_sesssetup *sess = s->sess;
        struct smbsrv_session *smb_sess = s->smb_sess;
        struct auth_session_info *session_info = NULL;
        NTSTATUS status;
        NTSTATUS skey_status;
        DATA_BLOB session_key;

        status = gensec_update_recv(greq, req, &sess->spnego.out.secblob);
        if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
                goto done;
        } else if (!NT_STATUS_IS_OK(status)) {
                goto failed;
        }

        status = gensec_session_info(smb_sess->gensec_ctx, &session_info);
        if (!NT_STATUS_IS_OK(status)) goto failed;

        skey_status = gensec_session_key(smb_sess->gensec_ctx, &session_key);
        if (NT_STATUS_IS_OK(skey_status)) {
                smbsrv_setup_signing(req->smb_conn, &session_key, NULL);
        }

        /* Ensure this is marked as a 'real' vuid, not one
         * simply valid for the session setup leg */
        status = smbsrv_session_sesssetup_finished(smb_sess, session_info);
        if (!NT_STATUS_IS_OK(status)) goto failed;

        req->session = smb_sess;

done:
        sess->spnego.out.vuid = smb_sess->vuid;
failed:
        status = auth_nt_status_squash(status);
        smbsrv_sesssetup_backend_send(req, sess, status);
        if (!NT_STATUS_IS_OK(status) && 
            !NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
                talloc_free(smb_sess);
        }
}

/*
  handler for SPNEGO style session setup
*/
static void sesssetup_spnego(struct smbsrv_request *req, union smb_sesssetup *sess)
{
        NTSTATUS status;
        struct smbsrv_session *smb_sess = NULL;
        struct sesssetup_spnego_state *s = NULL;
        uint16_t vuid;

        sess->spnego.out.vuid = 0;
        sess->spnego.out.action = 0;

        sesssetup_common_strings(req, 
                                 &sess->spnego.out.os,
                                 &sess->spnego.out.lanman,
                                 &sess->spnego.out.workgroup);

        if (!req->smb_conn->negotiate.done_sesssetup) {
                req->smb_conn->negotiate.max_send = sess->spnego.in.bufsize;
                req->smb_conn->negotiate.client_caps = sess->spnego.in.capabilities;
        }

        vuid = SVAL(req->in.hdr,HDR_UID);

        /* lookup an existing session */
        smb_sess = smbsrv_session_find_sesssetup(req->smb_conn, vuid);
        if (!smb_sess) {
                struct gensec_security *gensec_ctx;

                status = samba_server_gensec_start(req,
                                                   req->smb_conn->connection->event.ctx,
                                                   req->smb_conn->connection->msg_ctx,
                                                   req->smb_conn->lp_ctx,
                                                   req->smb_conn->negotiate.server_credentials,
                                                   "cifs",
                                                   &gensec_ctx);
                if (!NT_STATUS_IS_OK(status)) {
                        DEBUG(1, ("Failed to start GENSEC server code: %s\n", nt_errstr(status)));
                        goto failed;
                }

                gensec_want_feature(gensec_ctx, GENSEC_FEATURE_SESSION_KEY);

                status = gensec_start_mech_by_oid(gensec_ctx, req->smb_conn->negotiate.oid);
                if (!NT_STATUS_IS_OK(status)) {
                        DEBUG(1, ("Failed to start GENSEC %s server code: %s\n", 
                                  gensec_get_name_by_oid(gensec_ctx, req->smb_conn->negotiate.oid), nt_errstr(status)));
                        goto failed;
                }

                /* allocate a new session */
                smb_sess = smbsrv_session_new(req->smb_conn, req->smb_conn, gensec_ctx);
                if (!smb_sess) {
                        status = NT_STATUS_INSUFFICIENT_RESOURCES;
                        goto failed;
                }
        }

        if (!smb_sess) {
                status = NT_STATUS_ACCESS_DENIED;
                goto failed;
        }

        if (!smb_sess->gensec_ctx) {
                status = NT_STATUS_INTERNAL_ERROR;
                DEBUG(1, ("Internal ERROR: no gensec_ctx on session: %s\n", nt_errstr(status)));
                goto failed;
        }

        s = talloc(req, struct sesssetup_spnego_state);
        if (!s) goto nomem;
        s->req          = req;
        s->sess         = sess;
        s->smb_sess     = smb_sess;

        gensec_update_send(smb_sess->gensec_ctx, sess->spnego.in.secblob,
                           sesssetup_spnego_send, s);
        return;

nomem:
        status = NT_STATUS_NO_MEMORY;
failed:
        talloc_free(smb_sess);
        status = auth_nt_status_squash(status);
        smbsrv_sesssetup_backend_send(req, sess, status);
}

/*
  backend for sessionsetup call - this takes all 3 variants of the call
*/
void smbsrv_sesssetup_backend(struct smbsrv_request *req,
                              union smb_sesssetup *sess)
{
        switch (sess->old.level) {
                case RAW_SESSSETUP_OLD:
                        sesssetup_old(req, sess);
                        return;

                case RAW_SESSSETUP_NT1:
                        sesssetup_nt1(req, sess);
                        return;

                case RAW_SESSSETUP_SPNEGO:
                        sesssetup_spnego(req, sess);
                        return;

                case RAW_SESSSETUP_SMB2:
                        break;
        }

        smbsrv_sesssetup_backend_send(req, sess, NT_STATUS_INVALID_LEVEL);
}