source4/librpc/rpc/dcerpc_schannel.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    dcerpc schannel operations
   5
   6    Copyright (C) Andrew Tridgell 2004
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21 */
  22
  23 #include "includes.h"
  24
  25 /*
  26   wrappers for the schannel_*() functions
  27 */
  28 static NTSTATUS schan_unseal_packet(struct dcerpc_security *dcerpc_security,
  29                                   uchar *data, size_t length, DATA_BLOB *sig)
  30 {
  31         struct schannel_state *schannel_state = dcerpc_security->private;
  32         return schannel_unseal_packet(schannel_state, data, length, sig);
  33 }
  34
  35 static NTSTATUS schan_check_packet(struct dcerpc_security *dcerpc_security,
  36                                   const uchar *data, size_t length,
  37                                   const DATA_BLOB *sig)
  38 {
  39         struct schannel_state *schannel_state = dcerpc_security->private;
  40         return schannel_check_packet(schannel_state, data, length, sig);
  41 }
  42
  43 static NTSTATUS schan_seal_packet(struct dcerpc_security *dcerpc_security,
  44                                  uchar *data, size_t length,
  45                                  DATA_BLOB *sig)
  46 {
  47         struct schannel_state *schannel_state = dcerpc_security->private;
  48         return schannel_seal_packet(schannel_state, data, length, sig);
  49 }
  50
  51 static NTSTATUS schan_sign_packet(struct dcerpc_security *dcerpc_security,
  52                                  const uchar *data, size_t length,
  53                                  DATA_BLOB *sig)
  54 {
  55         struct schannel_state *schannel_state = dcerpc_security->private;
  56         return schannel_sign_packet(schannel_state, data, length, sig);
  57 }
  58
  59 static void schan_security_end(struct dcerpc_security *dcerpc_security)
  60 {
  61         struct schannel_state *schannel_state = dcerpc_security->private;
  62         return schannel_end(&schannel_state);
  63 }
  64
  65
  66 /*
  67   do a schannel style bind on a dcerpc pipe. The username is usually
  68   of the form HOSTNAME$ and the password is the domain trust password
  69 */
  70 NTSTATUS dcerpc_bind_auth_schannel(struct dcerpc_pipe *p,
  71                                    const char *uuid, unsigned version,
  72                                    const char *domain,
  73                                    const char *username,
  74                                    const char *password)
  75 {
  76         NTSTATUS status;
  77         struct dcerpc_pipe *p2;
  78         struct netr_ServerReqChallenge r;
  79         struct netr_ServerAuthenticate2 a;
  80         uint8 mach_pwd[16];
  81         uint8 session_key[16];
  82         struct netr_CredentialState creds;
  83         struct schannel_state *schannel_state;
  84         const char *workgroup, *workstation;
  85         uint32 negotiate_flags = 0;
  86
  87         workstation = username;
  88         workgroup = domain;
  89
  90         /*
  91           step 1 - establish a netlogon connection, with no authentication
  92         */
  93         status = dcerpc_secondary_smb(p, &p2,
  94                                       DCERPC_NETLOGON_NAME,
  95                                       DCERPC_NETLOGON_UUID,
  96                                       DCERPC_NETLOGON_VERSION);
  97
  98
  99         /*
 100           step 2 - request a netlogon challenge
 101         */
 102         r.in.server_name = talloc_asprintf(p->mem_ctx, "\\\\%s", dcerpc_server_name(p));
 103         r.in.computer_name = workstation;
 104         generate_random_buffer(r.in.credentials.data, sizeof(r.in.credentials.data), False);
 105
 106         status = dcerpc_netr_ServerReqChallenge(p2, p->mem_ctx, &r);
 107         if (!NT_STATUS_IS_OK(status)) {
 108                 return status;
 109         }
 110
 111         /*
 112           step 3 - authenticate on the netlogon pipe
 113         */
 114         E_md4hash(password, mach_pwd);
 115         creds_client_init(&creds, &r.in.credentials, &r.out.credentials, mach_pwd,
 116                           &a.in.credentials);
 117
 118         a.in.server_name = r.in.server_name;
 119         a.in.username = talloc_asprintf(p->mem_ctx, "%s$", workstation);
 120         if (lp_server_role() == ROLE_DOMAIN_BDC) {
 121                 a.in.secure_channel_type = SEC_CHAN_BDC;
 122         } else {
 123                 a.in.secure_channel_type = SEC_CHAN_WKSTA;
 124         }
 125         a.in.computer_name = workstation;
 126         a.in.negotiate_flags = &negotiate_flags;
 127         a.out.negotiate_flags = &negotiate_flags;
 128
 129         status = dcerpc_netr_ServerAuthenticate2(p2, p->mem_ctx, &a);
 130         if (!NT_STATUS_IS_OK(status)) {
 131                 return status;
 132         }
 133         if (!creds_client_check(&creds, &a.out.credentials)) {
 134                 return NT_STATUS_UNSUCCESSFUL;
 135         }
 136
 137         /*
 138           the schannel session key is now in creds.session_key
 139
 140           we no longer need the netlogon pipe open
 141         */
 142         dcerpc_pipe_close(p2);
 143
 144         /*
 145           step 4 - perform a bind with security type schannel
 146         */
 147         p->auth_info = talloc(p->mem_ctx, sizeof(*p->auth_info));
 148         if (!p->auth_info) {
 149                 status = NT_STATUS_NO_MEMORY;
 150                 goto done;
 151         }
 152
 153         p->auth_info->auth_type = DCERPC_AUTH_TYPE_SCHANNEL;
 154
 155         if (p->flags & DCERPC_SEAL) {
 156                 p->auth_info->auth_level = DCERPC_AUTH_LEVEL_PRIVACY;
 157         } else {
 158                 /* note that DCERPC_AUTH_LEVEL_NONE does not make any
 159                    sense, and would be rejected by the server */
 160                 p->auth_info->auth_level = DCERPC_AUTH_LEVEL_INTEGRITY;
 161         }
 162         p->auth_info->auth_pad_length = 0;
 163         p->auth_info->auth_reserved = 0;
 164         p->auth_info->auth_context_id = random();
 165         p->security_state = NULL;
 166
 167         p->auth_info->credentials = data_blob_talloc(p->mem_ctx,
 168                                                      NULL,
 169                                                      8 +
 170                                                      strlen(workgroup)+1 +
 171                                                      strlen(workstation)+1);
 172         if (!p->auth_info->credentials.data) {
 173                 return NT_STATUS_NO_MEMORY;
 174         }
 175
 176         /* oh, this is ugly! */
 177         SIVAL(p->auth_info->credentials.data, 0, 0);
 178         SIVAL(p->auth_info->credentials.data, 4, 3);
 179         memcpy(p->auth_info->credentials.data+8, workgroup, strlen(workgroup)+1);
 180         memcpy(p->auth_info->credentials.data+8+strlen(workgroup)+1,
 181                workstation, strlen(workstation)+1);
 182
 183         /* send the authenticated bind request */
 184         status = dcerpc_bind_byuuid(p, p->mem_ctx, uuid, version);
 185         if (!NT_STATUS_IS_OK(status)) {
 186                 goto done;
 187         }
 188
 189         p->security_state = talloc_p(p->mem_ctx, struct dcerpc_security);
 190         if (!p->security_state) {
 191                 status = NT_STATUS_NO_MEMORY;
 192                 goto done;
 193         }
 194
 195         schannel_state = talloc_p(p->mem_ctx, struct schannel_state);
 196         if (!schannel_state) {
 197                 status = NT_STATUS_NO_MEMORY;
 198                 goto done;
 199         }
 200
 201         memcpy(session_key, creds.session_key, 8);
 202         memset(session_key+8, 0, 8);
 203
 204         status = schannel_start(&schannel_state, session_key, True);
 205         if (!NT_STATUS_IS_OK(status)) {
 206                 goto done;
 207         }
 208
 209         dump_data_pw("session key:\n", schannel_state->session_key, 16);
 210
 211         p->security_state->private = schannel_state;
 212         p->security_state->unseal_packet = schan_unseal_packet;
 213         p->security_state->check_packet = schan_check_packet;
 214         p->security_state->seal_packet = schan_seal_packet;
 215         p->security_state->sign_packet = schan_sign_packet;
 216         p->security_state->security_end = schan_security_end;
 217
 218 done:
 219         return status;
 220 }
 221