/* Unix SMB/CIFS implementation. server side dcerpc authentication code Copyright (C) Andrew Tridgell 2003 Copyright (C) Stefan (metze) Metzmacher 2004 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 "rpc_server/dcerpc_server.h" #include "rpc_server/dcerpc_server_proto.h" #include "librpc/rpc/dcerpc_proto.h" #include "librpc/gen_ndr/ndr_dcerpc.h" #include "auth/credentials/credentials.h" #include "auth/gensec/gensec.h" #include "auth/auth.h" #include "param/param.h" /* parse any auth information from a dcerpc bind request return false if we can't handle the auth request for some reason (in which case we send a bind_nak) */ bool dcesrv_auth_bind(struct dcesrv_call_state *call) { struct cli_credentials *server_credentials; struct ncacn_packet *pkt = &call->pkt; struct dcesrv_connection *dce_conn = call->conn; struct dcesrv_auth *auth = &dce_conn->auth_state; NTSTATUS status; uint32_t auth_length; if (pkt->u.bind.auth_info.length == 0) { dce_conn->auth_state.auth_info = NULL; return true; } dce_conn->auth_state.auth_info = talloc(dce_conn, struct dcerpc_auth); if (!dce_conn->auth_state.auth_info) { return false; } status = dcerpc_pull_auth_trailer(pkt, call, &pkt->u.bind.auth_info, dce_conn->auth_state.auth_info, &auth_length, false); server_credentials = cli_credentials_init(call); if (!server_credentials) { DEBUG(1, ("Failed to init server credentials\n")); return false; } cli_credentials_set_conf(server_credentials, call->conn->dce_ctx->lp_ctx); status = cli_credentials_set_machine_account(server_credentials, call->conn->dce_ctx->lp_ctx); if (!NT_STATUS_IS_OK(status)) { DEBUG(10, ("Failed to obtain server credentials, perhaps a standalone server?: %s\n", nt_errstr(status))); talloc_free(server_credentials); server_credentials = NULL; } status = samba_server_gensec_start(dce_conn, call->event_ctx, call->msg_ctx, call->conn->dce_ctx->lp_ctx, server_credentials, NULL, &auth->gensec_security); status = gensec_start_mech_by_authtype(auth->gensec_security, auth->auth_info->auth_type, auth->auth_info->auth_level); if (!NT_STATUS_IS_OK(status)) { DEBUG(1, ("Failed to start GENSEC mechanism for DCERPC server: auth_type=%d, auth_level=%d: %s\n", (int)auth->auth_info->auth_type, (int)auth->auth_info->auth_level, nt_errstr(status))); return false; } if (call->conn->state_flags & DCESRV_CALL_STATE_FLAG_HEADER_SIGNING) { gensec_want_feature(auth->gensec_security, GENSEC_FEATURE_SIGN_PKT_HEADER); } return true; } /* add any auth information needed in a bind ack, and process the authentication information found in the bind. */ NTSTATUS dcesrv_auth_bind_ack(struct dcesrv_call_state *call, struct ncacn_packet *pkt) { struct dcesrv_connection *dce_conn = call->conn; NTSTATUS status; if (!call->conn->auth_state.gensec_security) { return NT_STATUS_OK; } status = gensec_update(dce_conn->auth_state.gensec_security, call, dce_conn->auth_state.auth_info->credentials, &dce_conn->auth_state.auth_info->credentials); if (NT_STATUS_IS_OK(status)) { status = gensec_session_info(dce_conn->auth_state.gensec_security, &dce_conn->auth_state.session_info); if (!NT_STATUS_IS_OK(status)) { DEBUG(1, ("Failed to establish session_info: %s\n", nt_errstr(status))); return status; } if (dce_conn->state_flags & DCESRV_CALL_STATE_FLAG_HEADER_SIGNING) { gensec_want_feature(dce_conn->auth_state.gensec_security, GENSEC_FEATURE_SIGN_PKT_HEADER); } /* Now that we are authenticated, go back to the generic session key... */ dce_conn->auth_state.session_key = dcesrv_generic_session_key; return NT_STATUS_OK; } else if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) { dce_conn->auth_state.auth_info->auth_pad_length = 0; dce_conn->auth_state.auth_info->auth_reserved = 0; return NT_STATUS_OK; } else { DEBUG(2, ("Failed to start dcesrv auth negotiate: %s\n", nt_errstr(status))); return status; } } /* process the final stage of a auth request */ bool dcesrv_auth_auth3(struct dcesrv_call_state *call) { struct ncacn_packet *pkt = &call->pkt; struct dcesrv_connection *dce_conn = call->conn; NTSTATUS status; uint32_t auth_length; /* We can't work without an existing gensec state, and an new blob to feed it */ if (!dce_conn->auth_state.auth_info || !dce_conn->auth_state.gensec_security || pkt->u.auth3.auth_info.length == 0) { return false; } status = dcerpc_pull_auth_trailer(pkt, call, &pkt->u.auth3.auth_info, dce_conn->auth_state.auth_info, &auth_length, true); if (!NT_STATUS_IS_OK(status)) { return false; } /* Pass the extra data we got from the client down to gensec for processing */ status = gensec_update(dce_conn->auth_state.gensec_security, call, dce_conn->auth_state.auth_info->credentials, &dce_conn->auth_state.auth_info->credentials); if (NT_STATUS_IS_OK(status)) { status = gensec_session_info(dce_conn->auth_state.gensec_security, &dce_conn->auth_state.session_info); if (!NT_STATUS_IS_OK(status)) { DEBUG(1, ("Failed to establish session_info: %s\n", nt_errstr(status))); return false; } /* Now that we are authenticated, go back to the generic session key... */ dce_conn->auth_state.session_key = dcesrv_generic_session_key; return true; } else { DEBUG(4, ("dcesrv_auth_auth3: failed to authenticate: %s\n", nt_errstr(status))); return false; } return true; } /* parse any auth information from a dcerpc alter request return false if we can't handle the auth request for some reason (in which case we send a bind_nak (is this true for here?)) */ bool dcesrv_auth_alter(struct dcesrv_call_state *call) { struct ncacn_packet *pkt = &call->pkt; struct dcesrv_connection *dce_conn = call->conn; NTSTATUS status; uint32_t auth_length; /* on a pure interface change there is no auth blob */ if (pkt->u.alter.auth_info.length == 0) { return true; } /* We can't work without an existing gensec state */ if (!dce_conn->auth_state.gensec_security) { return false; } dce_conn->auth_state.auth_info = talloc(dce_conn, struct dcerpc_auth); if (!dce_conn->auth_state.auth_info) { return false; } status = dcerpc_pull_auth_trailer(pkt, call, &pkt->u.alter.auth_info, dce_conn->auth_state.auth_info, &auth_length, true); if (!NT_STATUS_IS_OK(status)) { return false; } return true; } /* add any auth information needed in a alter ack, and process the authentication information found in the alter. */ NTSTATUS dcesrv_auth_alter_ack(struct dcesrv_call_state *call, struct ncacn_packet *pkt) { struct dcesrv_connection *dce_conn = call->conn; NTSTATUS status; /* on a pure interface change there is no auth_info structure setup */ if (!call->conn->auth_state.auth_info || dce_conn->auth_state.auth_info->credentials.length == 0) { return NT_STATUS_OK; } if (!call->conn->auth_state.gensec_security) { return NT_STATUS_INVALID_PARAMETER; } status = gensec_update(dce_conn->auth_state.gensec_security, call, dce_conn->auth_state.auth_info->credentials, &dce_conn->auth_state.auth_info->credentials); if (NT_STATUS_IS_OK(status)) { status = gensec_session_info(dce_conn->auth_state.gensec_security, &dce_conn->auth_state.session_info); if (!NT_STATUS_IS_OK(status)) { DEBUG(1, ("Failed to establish session_info: %s\n", nt_errstr(status))); return status; } /* Now that we are authenticated, got back to the generic session key... */ dce_conn->auth_state.session_key = dcesrv_generic_session_key; return NT_STATUS_OK; } else if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) { dce_conn->auth_state.auth_info->auth_pad_length = 0; dce_conn->auth_state.auth_info->auth_reserved = 0; return NT_STATUS_OK; } DEBUG(2, ("Failed to finish dcesrv auth alter_ack: %s\n", nt_errstr(status))); return status; } /* check credentials on a request */ bool dcesrv_auth_request(struct dcesrv_call_state *call, DATA_BLOB *full_packet) { struct ncacn_packet *pkt = &call->pkt; struct dcesrv_connection *dce_conn = call->conn; struct dcerpc_auth auth; NTSTATUS status; uint32_t auth_length; size_t hdr_size = DCERPC_REQUEST_LENGTH; if (!dce_conn->auth_state.auth_info || !dce_conn->auth_state.gensec_security) { return true; } if (pkt->pfc_flags & DCERPC_PFC_FLAG_OBJECT_UUID) { hdr_size += 16; } switch (dce_conn->auth_state.auth_info->auth_level) { case DCERPC_AUTH_LEVEL_PRIVACY: case DCERPC_AUTH_LEVEL_INTEGRITY: break; case DCERPC_AUTH_LEVEL_CONNECT: if (pkt->auth_length != 0) { break; } return true; case DCERPC_AUTH_LEVEL_NONE: if (pkt->auth_length != 0) { return false; } return true; default: return false; } status = dcerpc_pull_auth_trailer(pkt, call, &pkt->u.request.stub_and_verifier, &auth, &auth_length, false); if (!NT_STATUS_IS_OK(status)) { return false; } pkt->u.request.stub_and_verifier.length -= auth_length; /* check signature or unseal the packet */ switch (dce_conn->auth_state.auth_info->auth_level) { case DCERPC_AUTH_LEVEL_PRIVACY: status = gensec_unseal_packet(dce_conn->auth_state.gensec_security, call, full_packet->data + hdr_size, pkt->u.request.stub_and_verifier.length, full_packet->data, full_packet->length-auth.credentials.length, &auth.credentials); memcpy(pkt->u.request.stub_and_verifier.data, full_packet->data + hdr_size, pkt->u.request.stub_and_verifier.length); break; case DCERPC_AUTH_LEVEL_INTEGRITY: status = gensec_check_packet(dce_conn->auth_state.gensec_security, call, pkt->u.request.stub_and_verifier.data, pkt->u.request.stub_and_verifier.length, full_packet->data, full_packet->length-auth.credentials.length, &auth.credentials); break; case DCERPC_AUTH_LEVEL_CONNECT: /* for now we ignore possible signatures here */ status = NT_STATUS_OK; break; default: status = NT_STATUS_INVALID_LEVEL; break; } /* remove the indicated amount of padding */ if (pkt->u.request.stub_and_verifier.length < auth.auth_pad_length) { return false; } pkt->u.request.stub_and_verifier.length -= auth.auth_pad_length; return NT_STATUS_IS_OK(status); } /* push a signed or sealed dcerpc request packet into a blob */ bool dcesrv_auth_response(struct dcesrv_call_state *call, DATA_BLOB *blob, size_t sig_size, struct ncacn_packet *pkt) { struct dcesrv_connection *dce_conn = call->conn; NTSTATUS status; enum ndr_err_code ndr_err; struct ndr_push *ndr; uint32_t payload_length; DATA_BLOB creds2; /* non-signed packets are simple */ if (sig_size == 0) { status = ncacn_push_auth(blob, call, lp_iconv_convenience(dce_conn->dce_ctx->lp_ctx), pkt, NULL); return NT_STATUS_IS_OK(status); } switch (dce_conn->auth_state.auth_info->auth_level) { case DCERPC_AUTH_LEVEL_PRIVACY: case DCERPC_AUTH_LEVEL_INTEGRITY: break; case DCERPC_AUTH_LEVEL_CONNECT: /* * TODO: let the gensec mech decide if it wants to generate a signature * that might be needed for schannel... */ status = ncacn_push_auth(blob, call, lp_iconv_convenience(dce_conn->dce_ctx->lp_ctx), pkt, NULL); return NT_STATUS_IS_OK(status); case DCERPC_AUTH_LEVEL_NONE: status = ncacn_push_auth(blob, call, lp_iconv_convenience(dce_conn->dce_ctx->lp_ctx), pkt, NULL); return NT_STATUS_IS_OK(status); default: return false; } ndr = ndr_push_init_ctx(call, lp_iconv_convenience(dce_conn->dce_ctx->lp_ctx)); if (!ndr) { return false; } if (!(pkt->drep[0] & DCERPC_DREP_LE)) { ndr->flags |= LIBNDR_FLAG_BIGENDIAN; } ndr_err = ndr_push_ncacn_packet(ndr, NDR_SCALARS|NDR_BUFFERS, pkt); if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) { return false; } /* pad to 16 byte multiple in the payload portion of the packet. This matches what w2k3 does. Note that we can't use ndr_push_align() as that is relative to the start of the whole packet, whereas w2k8 wants it relative to the start of the stub */ dce_conn->auth_state.auth_info->auth_pad_length = (16 - (pkt->u.response.stub_and_verifier.length & 15)) & 15; ndr_err = ndr_push_zero(ndr, dce_conn->auth_state.auth_info->auth_pad_length); if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) { return false; } payload_length = pkt->u.response.stub_and_verifier.length + dce_conn->auth_state.auth_info->auth_pad_length; /* we start without signature, it will appended later */ dce_conn->auth_state.auth_info->credentials = data_blob(NULL, 0); /* add the auth verifier */ ndr_err = ndr_push_dcerpc_auth(ndr, NDR_SCALARS|NDR_BUFFERS, dce_conn->auth_state.auth_info); if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) { return false; } /* extract the whole packet as a blob */ *blob = ndr_push_blob(ndr); /* * Setup the frag and auth length in the packet buffer. * This is needed if the GENSEC mech does AEAD signing * of the packet headers. The signature itself will be * appended later. */ dcerpc_set_frag_length(blob, blob->length + sig_size); dcerpc_set_auth_length(blob, sig_size); /* sign or seal the packet */ switch (dce_conn->auth_state.auth_info->auth_level) { case DCERPC_AUTH_LEVEL_PRIVACY: status = gensec_seal_packet(dce_conn->auth_state.gensec_security, call, ndr->data + DCERPC_REQUEST_LENGTH, payload_length, blob->data, blob->length, &creds2); break; case DCERPC_AUTH_LEVEL_INTEGRITY: status = gensec_sign_packet(dce_conn->auth_state.gensec_security, call, ndr->data + DCERPC_REQUEST_LENGTH, payload_length, blob->data, blob->length, &creds2); break; default: status = NT_STATUS_INVALID_LEVEL; break; } if (!NT_STATUS_IS_OK(status)) { return false; } if (creds2.length != sig_size) { DEBUG(3,("dcesrv_auth_response: creds2.length[%u] != sig_size[%u] pad[%u] stub[%u]\n", (unsigned)creds2.length, (uint32_t)sig_size, (unsigned)dce_conn->auth_state.auth_info->auth_pad_length, (unsigned)pkt->u.response.stub_and_verifier.length)); dcerpc_set_frag_length(blob, blob->length + creds2.length); dcerpc_set_auth_length(blob, creds2.length); } if (!data_blob_append(call, blob, creds2.data, creds2.length)) { status = NT_STATUS_NO_MEMORY; return false; } data_blob_free(&creds2); return true; }