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 #define DCERPC_SCHANNEL_STATE_START 0
  26 #define DCERPC_SCHANNEL_STATE_UPDATE_1 1
  27
  28 struct dcerpc_schannel_state {
  29         TALLOC_CTX *mem_ctx;
  30         uint8_t state;
  31         struct schannel_bind bind_schannel;
  32         struct schannel_state *schannel_state;
  33 };
  34
  35 static NTSTATUS dcerpc_schannel_key(struct dcerpc_pipe *p,
  36                              const char *domain,
  37                              const char *username,
  38                              const char *password,
  39                              int chan_type,
  40                                     uint8_t new_session_key[16]);
  41
  42 /*
  43   wrappers for the schannel_*() functions
  44
  45   These will become static again, when we get dynamic registration, and
  46   decrpc_schannel_security_ops come back here.
  47 */
  48 static NTSTATUS dcerpc_schannel_unseal(struct gensec_security *gensec_security,
  49                                     TALLOC_CTX *mem_ctx,
  50                                     uint8_t *data, size_t length, DATA_BLOB *sig)
  51 {
  52         struct dcerpc_schannel_state *dce_schan_state = gensec_security->private_data;
  53
  54         return schannel_unseal_packet(dce_schan_state->schannel_state, mem_ctx, data, length, sig);
  55 }
  56
  57 static NTSTATUS dcerpc_schannel_check_sig(struct gensec_security *gensec_security,
  58                                    TALLOC_CTX *mem_ctx,
  59                                    const uint8_t *data, size_t length,
  60                                    const DATA_BLOB *sig)
  61 {
  62         struct dcerpc_schannel_state *dce_schan_state = gensec_security->private_data;
  63
  64         return schannel_check_packet(dce_schan_state->schannel_state, data, length, sig);
  65 }
  66
  67 static NTSTATUS dcerpc_schannel_seal(struct gensec_security *gensec_security,
  68                                   TALLOC_CTX *mem_ctx,
  69                                   uint8_t *data, size_t length,
  70                                   DATA_BLOB *sig)
  71 {
  72         struct dcerpc_schannel_state *dce_schan_state = gensec_security->private_data;
  73
  74         return schannel_seal_packet(dce_schan_state->schannel_state, mem_ctx, data, length, sig);
  75 }
  76
  77 static NTSTATUS dcerpc_schannel_sign(struct gensec_security *gensec_security,
  78                                  TALLOC_CTX *mem_ctx,
  79                                  const uint8_t *data, size_t length,
  80                                  DATA_BLOB *sig)
  81 {
  82         struct dcerpc_schannel_state *dce_schan_state = gensec_security->private_data;
  83
  84         return schannel_sign_packet(dce_schan_state->schannel_state, mem_ctx, data, length, sig);
  85 }
  86
  87 static NTSTATUS dcerpc_schannel_session_key(struct gensec_security *gensec_security,
  88                                   DATA_BLOB *session_key)
  89 {
  90         return NT_STATUS_NOT_IMPLEMENTED;
  91 }
  92
  93 static NTSTATUS dcerpc_schannel_update(struct gensec_security *gensec_security, TALLOC_CTX *out_mem_ctx,
  94                                                 const DATA_BLOB in, DATA_BLOB *out)
  95 {
  96         struct dcerpc_schannel_state *dce_schan_state = gensec_security->private_data;
  97         NTSTATUS status;
  98         struct schannel_bind bind_schannel;
  99
 100         if (dce_schan_state->state != DCERPC_SCHANNEL_STATE_START) {
 101                 return NT_STATUS_OK;
 102         }
 103
 104         dce_schan_state->state = DCERPC_SCHANNEL_STATE_UPDATE_1;
 105
 106         bind_schannel.unknown1 = 0;
 107 #if 0
 108         /* to support this we'd need to have access to the full domain name */
 109         bind_schannel.bind_type = 23;
 110         bind_schannel.u.info23.domain = gensec_security->user.domain;
 111         bind_schannel.u.info23.account_name = gensec_security->user.name;
 112         bind_schannel.u.info23.dnsdomain = str_format_nbt_domain(dce_schan_state->mem_ctx, fulldomainname);
 113         bind_schannel.u.info23.workstation = str_format_nbt_domain(dce_schan_state->mem_ctx, gensec_security->user.name);
 114 #else
 115         bind_schannel.bind_type = 3;
 116         bind_schannel.u.info3.domain = gensec_security->user.domain;
 117         bind_schannel.u.info3.account_name = gensec_security->user.name;
 118 #endif
 119
 120         status = ndr_push_struct_blob(out, dce_schan_state->mem_ctx, &bind_schannel,
 121                                       (ndr_push_flags_fn_t)ndr_push_schannel_bind);
 122         if (!NT_STATUS_IS_OK(status)) {
 123                 return status;
 124         }
 125
 126         return NT_STATUS_MORE_PROCESSING_REQUIRED;
 127 }
 128
 129 static void dcerpc_schannel_end(struct gensec_security *gensec_security)
 130 {
 131         struct dcerpc_schannel_state *dce_schan_state = gensec_security->private_data;
 132
 133         schannel_end(&dce_schan_state->schannel_state);
 134
 135         talloc_destroy(dce_schan_state->mem_ctx);
 136
 137         gensec_security->private_data = NULL;
 138 }
 139
 140
 141 static const struct gensec_security_ops gensec_dcerpc_schannel_security_ops = {
 142         .name           = "dcerpc_schannel",
 143         .auth_type      = DCERPC_AUTH_TYPE_SCHANNEL,
 144         .update         = dcerpc_schannel_update,
 145         .seal           = dcerpc_schannel_seal,
 146         .sign           = dcerpc_schannel_sign,
 147         .check_sig      = dcerpc_schannel_check_sig,
 148         .unseal         = dcerpc_schannel_unseal,
 149         .session_key    = dcerpc_schannel_session_key,
 150         .end            = dcerpc_schannel_end
 151 };
 152
 153 /*
 154   get a schannel key using a netlogon challenge on a secondary pipe
 155 */
 156 static NTSTATUS dcerpc_schannel_key(struct dcerpc_pipe *p,
 157                                     const char *domain,
 158                                     const char *username,
 159                                     const char *password,
 160                                     int chan_type,
 161                                     uint8_t new_session_key[16])
 162 {
 163         NTSTATUS status;
 164         struct dcerpc_pipe *p2;
 165         struct netr_ServerReqChallenge r;
 166         struct netr_ServerAuthenticate2 a;
 167         struct netr_Credential credentials1, credentials2, credentials3;
 168         struct samr_Password mach_pwd;
 169         struct creds_CredentialState creds;
 170         const char *workgroup, *workstation;
 171         uint32_t negotiate_flags;
 172
 173         if (p->flags & DCERPC_SCHANNEL_128) {
 174                 negotiate_flags = NETLOGON_NEG_AUTH2_ADS_FLAGS;
 175         } else {
 176                 negotiate_flags = NETLOGON_NEG_AUTH2_FLAGS;
 177         }
 178
 179         workstation = username;
 180         workgroup = domain;
 181
 182         /*
 183           step 1 - establish a netlogon connection, with no authentication
 184         */
 185         status = dcerpc_secondary_connection(p, &p2,
 186                                              DCERPC_NETLOGON_NAME,
 187                                              DCERPC_NETLOGON_UUID,
 188                                              DCERPC_NETLOGON_VERSION);
 189
 190
 191         /*
 192           step 2 - request a netlogon challenge
 193         */
 194         r.in.server_name = talloc_asprintf(p->mem_ctx, "\\\\%s", dcerpc_server_name(p));
 195         r.in.computer_name = workstation;
 196         r.in.credentials = &credentials1;
 197         r.out.credentials = &credentials2;
 198
 199         generate_random_buffer(credentials1.data, sizeof(credentials1.data), False);
 200
 201         status = dcerpc_netr_ServerReqChallenge(p2, p->mem_ctx, &r);
 202         if (!NT_STATUS_IS_OK(status)) {
 203                 return status;
 204         }
 205
 206         /*
 207           step 3 - authenticate on the netlogon pipe
 208         */
 209         E_md4hash(password, mach_pwd.hash);
 210         creds_client_init(&creds, &credentials1, &credentials2, &mach_pwd, &credentials3,
 211                           negotiate_flags);
 212
 213         a.in.server_name = r.in.server_name;
 214         a.in.account_name = talloc_asprintf(p->mem_ctx, "%s$", workstation);
 215         a.in.secure_channel_type = chan_type;
 216         a.in.computer_name = workstation;
 217         a.in.negotiate_flags = &negotiate_flags;
 218         a.out.negotiate_flags = &negotiate_flags;
 219         a.in.credentials = &credentials3;
 220         a.out.credentials = &credentials3;
 221
 222         status = dcerpc_netr_ServerAuthenticate2(p2, p->mem_ctx, &a);
 223         if (!NT_STATUS_IS_OK(status)) {
 224                 return status;
 225         }
 226
 227         if (!creds_client_check(&creds, a.out.credentials)) {
 228                 return NT_STATUS_UNSUCCESSFUL;
 229         }
 230
 231         /*
 232           the schannel session key is now in creds.session_key
 233
 234           we no longer need the netlogon pipe open
 235         */
 236         dcerpc_pipe_close(p2);
 237
 238         memcpy(new_session_key, creds.session_key, 16);
 239
 240         return NT_STATUS_OK;
 241 }
 242
 243 /*
 244   do a schannel style bind on a dcerpc pipe. The username is usually
 245   of the form HOSTNAME$ and the password is the domain trust password
 246 */
 247 NTSTATUS dcerpc_bind_auth_schannel(struct dcerpc_pipe *p,
 248                                    const char *uuid, uint_t version,
 249                                    const char *domain,
 250                                    const char *username,
 251                                    const char *password)
 252 {
 253         NTSTATUS status;
 254         struct dcerpc_schannel_state *dce_schan_state;
 255         TALLOC_CTX *mem_ctx;
 256         uint8_t session_key[16];
 257         int chan_type = 0;
 258
 259         if (p->flags & DCERPC_SCHANNEL_BDC) {
 260                 chan_type = SEC_CHAN_BDC;
 261         } else if (p->flags & DCERPC_SCHANNEL_WORKSTATION) {
 262                 chan_type = SEC_CHAN_WKSTA;
 263         } else if (p->flags & DCERPC_SCHANNEL_DOMAIN) {
 264                 chan_type = SEC_CHAN_DOMAIN;
 265         }
 266
 267         status = dcerpc_schannel_key(p, domain,
 268                                         username,
 269                                         password,
 270                                         chan_type, session_key);
 271         if (!NT_STATUS_IS_OK(status)) {
 272                 return status;
 273         }
 274
 275         mem_ctx = talloc_init("dcerpc_schannel_start");
 276         if (!mem_ctx) {
 277                 return NT_STATUS_NO_MEMORY;
 278         }
 279
 280         dce_schan_state = talloc_p(mem_ctx, struct dcerpc_schannel_state);
 281         if (!dce_schan_state) {
 282                 talloc_destroy(mem_ctx);
 283                 return NT_STATUS_NO_MEMORY;
 284         }
 285
 286         dce_schan_state->mem_ctx = mem_ctx;
 287
 288         status = schannel_start(&dce_schan_state->schannel_state, session_key, True);
 289         if (!NT_STATUS_IS_OK(status)) {
 290                 return status;
 291         }
 292
 293         dce_schan_state->state = DCERPC_SCHANNEL_STATE_START;
 294
 295         p->security_state.generic_state.user.domain = domain;
 296         p->security_state.generic_state.user.name = username;
 297         p->security_state.generic_state.user.password = password;
 298
 299         p->security_state.generic_state.ops = &gensec_dcerpc_schannel_security_ops;
 300         p->security_state.generic_state.private_data = dce_schan_state;
 301
 302         dump_data_pw("session key:\n", dce_schan_state->schannel_state->session_key, 16);
 303
 304         status = dcerpc_bind_auth(p, DCERPC_AUTH_TYPE_SCHANNEL,
 305                                   uuid, version);
 306
 307         return status;
 308 }