source/librpc/rpc/dcerpc_schannel.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    dcerpc schannel operations
   5
   6    Copyright (C) Andrew Tridgell 2004
   7    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2005
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 2 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program; if not, write to the Free Software
  21    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22 */
  23
  24 #include "includes.h"
  25 #include "librpc/gen_ndr/ndr_schannel.h"
  26 #include "auth/auth.h"
  27
  28 /*
  29   get a schannel key using a netlogon challenge on a secondary pipe
  30 */
  31 static NTSTATUS dcerpc_schannel_key(TALLOC_CTX *tmp_ctx,
  32                                     struct dcerpc_pipe *p,
  33                                     struct cli_credentials *credentials)
  34 {
  35         NTSTATUS status;
  36         struct dcerpc_binding *b;
  37         struct dcerpc_pipe *p2;
  38         struct netr_ServerReqChallenge r;
  39         struct netr_ServerAuthenticate2 a;
  40         struct netr_Credential credentials1, credentials2, credentials3;
  41         const struct samr_Password *mach_pwd;
  42         uint32_t negotiate_flags;
  43         struct creds_CredentialState *creds;
  44         creds = talloc(tmp_ctx, struct creds_CredentialState);
  45         if (!creds) {
  46                 return NT_STATUS_NO_MEMORY;
  47         }
  48
  49         if (p->conn->flags & DCERPC_SCHANNEL_128) {
  50                 negotiate_flags = NETLOGON_NEG_AUTH2_ADS_FLAGS;
  51         } else {
  52                 negotiate_flags = NETLOGON_NEG_AUTH2_FLAGS;
  53         }
  54
  55         /*
  56           step 1 - establish a netlogon connection, with no authentication
  57         */
  58
  59         /* Find the original binding string */
  60         status = dcerpc_parse_binding(tmp_ctx, p->conn->binding_string, &b);
  61         if (!NT_STATUS_IS_OK(status)) {
  62                 DEBUG(0,("Failed to parse dcerpc binding '%s'\n", p->conn->binding_string));
  63                 return status;
  64         }
  65
  66         /* Make binding string for netlogon, not the other pipe */
  67         status = dcerpc_epm_map_binding(tmp_ctx, b,
  68                                         DCERPC_NETLOGON_UUID, DCERPC_NETLOGON_VERSION,
  69                                         p->conn->event_ctx);
  70         if (!NT_STATUS_IS_OK(status)) {
  71                 DEBUG(0,("Failed to map DCERPC/TCP NCACN_NP pipe for '%s' - %s\n",
  72                          DCERPC_NETLOGON_UUID, nt_errstr(status)));
  73                 return status;
  74         }
  75
  76         status = dcerpc_secondary_connection(p, &p2, b);
  77         if (!NT_STATUS_IS_OK(status)) {
  78                 return status;
  79         }
  80
  81         status = dcerpc_bind_auth_none(p2, DCERPC_NETLOGON_UUID,
  82                                        DCERPC_NETLOGON_VERSION);
  83         if (!NT_STATUS_IS_OK(status)) {
  84                 talloc_free(p2);
  85                 return status;
  86         }
  87
  88         /*
  89           step 2 - request a netlogon challenge
  90         */
  91         r.in.server_name = talloc_asprintf(tmp_ctx, "\\\\%s", dcerpc_server_name(p));
  92         r.in.computer_name = cli_credentials_get_workstation(credentials);
  93         r.in.credentials = &credentials1;
  94         r.out.credentials = &credentials2;
  95
  96         generate_random_buffer(credentials1.data, sizeof(credentials1.data));
  97
  98         status = dcerpc_netr_ServerReqChallenge(p2, tmp_ctx, &r);
  99         if (!NT_STATUS_IS_OK(status)) {
 100                 return status;
 101         }
 102
 103         /*
 104           step 3 - authenticate on the netlogon pipe
 105         */
 106         mach_pwd = cli_credentials_get_nt_hash(credentials, tmp_ctx);
 107
 108         creds_client_init(creds, &credentials1, &credentials2,
 109                           mach_pwd, &credentials3,
 110                           negotiate_flags);
 111
 112         a.in.server_name = r.in.server_name;
 113         a.in.account_name = cli_credentials_get_username(credentials);
 114         a.in.secure_channel_type =
 115                 cli_credentials_get_secure_channel_type(credentials);
 116         a.in.computer_name = cli_credentials_get_workstation(credentials);
 117         a.in.negotiate_flags = &negotiate_flags;
 118         a.out.negotiate_flags = &negotiate_flags;
 119         a.in.credentials = &credentials3;
 120         a.out.credentials = &credentials3;
 121
 122         status = dcerpc_netr_ServerAuthenticate2(p2, tmp_ctx, &a);
 123         if (!NT_STATUS_IS_OK(status)) {
 124                 return status;
 125         }
 126
 127         if (!creds_client_check(creds, a.out.credentials)) {
 128                 return NT_STATUS_UNSUCCESSFUL;
 129         }
 130
 131         cli_credentials_set_netlogon_creds(credentials, creds);
 132
 133         /*
 134           the schannel session key is now in creds.session_key
 135
 136           we no longer need the netlogon pipe open
 137         */
 138         talloc_free(p2);
 139
 140         return NT_STATUS_OK;
 141 }
 142
 143 NTSTATUS dcerpc_bind_auth_schannel(TALLOC_CTX *tmp_ctx,
 144                                    struct dcerpc_pipe *p,
 145                                    const char *uuid, uint_t version,
 146                                    struct cli_credentials *credentials)
 147 {
 148         NTSTATUS status;
 149
 150         /* Fills in NETLOGON credentials */
 151         status = dcerpc_schannel_key(tmp_ctx,
 152                                      p, credentials);
 153
 154         if (!NT_STATUS_IS_OK(status)) {
 155                 DEBUG(1, ("Failed to setup credentials for account %s: %s\n",
 156                           cli_credentials_get_username(credentials),
 157                           nt_errstr(status)));
 158                 return status;
 159         }
 160
 161         return dcerpc_bind_auth(p, uuid, version,
 162                                 credentials, DCERPC_AUTH_TYPE_SCHANNEL,
 163                                 NULL);
 164 }
 165