Exemple #1
0
static NTSTATUS smb1srv_session_local_allocate_id(struct db_context *db,
						  uint32_t lowest_id,
						  uint32_t highest_id,
						  TALLOC_CTX *mem_ctx,
						  struct db_record **_rec,
						  uint32_t *_id)
{
	struct smb1srv_session_local_allocate_state state = {
		.lowest_id = lowest_id,
		.highest_id = highest_id,
		.last_id = 0,
		.useable_id = lowest_id,
		.status = NT_STATUS_INTERNAL_ERROR,
	};
	uint32_t i;
	uint32_t range;
	NTSTATUS status;
	int count = 0;

	*_rec = NULL;
	*_id = 0;

	if (lowest_id > highest_id) {
		return NT_STATUS_INSUFFICIENT_RESOURCES;
	}

	/*
	 * first we try randomly
	 */
	range = (highest_id - lowest_id) + 1;

	for (i = 0; i < (range / 2); i++) {
		uint32_t id;
		TDB_DATA val;
		struct db_record *rec = NULL;

		id = generate_random() % range;
		id += lowest_id;

		if (id < lowest_id) {
			id = lowest_id;
		}
		if (id > highest_id) {
			id = highest_id;
		}

		rec = smbXsrv_session_local_fetch_locked(db, id, mem_ctx);
		if (rec == NULL) {
			return NT_STATUS_INSUFFICIENT_RESOURCES;
		}

		val = dbwrap_record_get_value(rec);
		if (val.dsize != 0) {
			TALLOC_FREE(rec);
			continue;
		}

		*_rec = rec;
		*_id = id;
		return NT_STATUS_OK;
	}

	/*
	 * if the range is almost full,
	 * we traverse the whole table
	 * (this relies on sorted behavior of dbwrap_rbt)
	 */
	status = dbwrap_traverse_read(db, smb1srv_session_local_allocate_traverse,
				      &state, &count);
	if (NT_STATUS_IS_OK(status)) {
		if (NT_STATUS_IS_OK(state.status)) {
			return NT_STATUS_INTERNAL_ERROR;
		}

		if (!NT_STATUS_EQUAL(state.status, NT_STATUS_INTERNAL_ERROR)) {
			return state.status;
		}

		if (state.useable_id <= state.highest_id) {
			state.status = NT_STATUS_OK;
		} else {
			return NT_STATUS_INSUFFICIENT_RESOURCES;
		}
	} else if (!NT_STATUS_EQUAL(status, NT_STATUS_INTERNAL_DB_CORRUPTION)) {
		/*
		 * Here we really expect NT_STATUS_INTERNAL_DB_CORRUPTION!
		 *
		 * If we get anything else it is an error, because it
		 * means we did not manage to find a free slot in
		 * the db.
		 */
		return NT_STATUS_INSUFFICIENT_RESOURCES;
	}

	if (NT_STATUS_IS_OK(state.status)) {
		uint32_t id;
		TDB_DATA val;
		struct db_record *rec = NULL;

		id = state.useable_id;

		rec = smbXsrv_session_local_fetch_locked(db, id, mem_ctx);
		if (rec == NULL) {
			return NT_STATUS_INSUFFICIENT_RESOURCES;
		}

		val = dbwrap_record_get_value(rec);
		if (val.dsize != 0) {
			TALLOC_FREE(rec);
			return NT_STATUS_INTERNAL_DB_CORRUPTION;
		}

		*_rec = rec;
		*_id = id;
		return NT_STATUS_OK;
	}

	return state.status;
}

struct smbXsrv_session_local_fetch_state {
	struct smbXsrv_session *session;
	NTSTATUS status;
};

static void smbXsrv_session_local_fetch_parser(TDB_DATA key, TDB_DATA data,
					       void *private_data)
{
	struct smbXsrv_session_local_fetch_state *state =
		(struct smbXsrv_session_local_fetch_state *)private_data;
	void *ptr;

	if (data.dsize != sizeof(ptr)) {
		state->status = NT_STATUS_INTERNAL_DB_ERROR;
		return;
	}

	memcpy(&ptr, data.dptr, data.dsize);
	state->session = talloc_get_type_abort(ptr, struct smbXsrv_session);
	state->status = NT_STATUS_OK;
}

static NTSTATUS smbXsrv_session_local_lookup(struct smbXsrv_session_table *table,
					     /* conn: optional */
					     struct smbXsrv_connection *conn,
					     uint32_t session_local_id,
					     NTTIME now,
					     struct smbXsrv_session **_session)
{
	struct smbXsrv_session_local_fetch_state state = {
		.session = NULL,
		.status = NT_STATUS_INTERNAL_ERROR,
	};
	uint8_t key_buf[SMBXSRV_SESSION_LOCAL_TDB_KEY_SIZE];
	TDB_DATA key;
	NTSTATUS status;

	*_session = NULL;

	if (session_local_id == 0) {
		return NT_STATUS_USER_SESSION_DELETED;
	}

	if (table == NULL) {
		/* this might happen before the end of negprot */
		return NT_STATUS_USER_SESSION_DELETED;
	}

	if (table->local.db_ctx == NULL) {
		return NT_STATUS_INTERNAL_ERROR;
	}

	key = smbXsrv_session_local_id_to_key(session_local_id, key_buf);

	status = dbwrap_parse_record(table->local.db_ctx, key,
				     smbXsrv_session_local_fetch_parser,
				     &state);
	if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
		return NT_STATUS_USER_SESSION_DELETED;
	} else if (!NT_STATUS_IS_OK(status)) {
		return status;
	}
	if (!NT_STATUS_IS_OK(state.status)) {
		return state.status;
	}

	if (NT_STATUS_EQUAL(state.session->status, NT_STATUS_USER_SESSION_DELETED)) {
		return NT_STATUS_USER_SESSION_DELETED;
	}

	/*
	 * If a connection is specified check if the session is
	 * valid on the channel.
	 */
	if (conn != NULL) {
		struct smbXsrv_channel_global0 *c = NULL;

		status = smbXsrv_session_find_channel(state.session, conn, &c);
		if (!NT_STATUS_IS_OK(status)) {
			return status;
		}
	}

	state.session->idle_time = now;

	if (!NT_STATUS_IS_OK(state.session->status)) {
		*_session = state.session;
		return state.session->status;
	}

	if (now > state.session->global->expiration_time) {
		state.session->status = NT_STATUS_NETWORK_SESSION_EXPIRED;
	}

	*_session = state.session;
	return state.session->status;
}

static int smbXsrv_session_global_destructor(struct smbXsrv_session_global0 *global)
{
	return 0;
}

static void smbXsrv_session_global_verify_record(struct db_record *db_rec,
					bool *is_free,
					bool *was_free,
					TALLOC_CTX *mem_ctx,
					struct smbXsrv_session_global0 **_g);

static NTSTATUS smbXsrv_session_global_allocate(struct db_context *db,
					TALLOC_CTX *mem_ctx,
					struct smbXsrv_session_global0 **_global)
{
	uint32_t i;
	struct smbXsrv_session_global0 *global = NULL;
	uint32_t last_free = 0;
	const uint32_t min_tries = 3;

	*_global = NULL;

	global = talloc_zero(mem_ctx, struct smbXsrv_session_global0);
	if (global == NULL) {
		return NT_STATUS_NO_MEMORY;
	}
	talloc_set_destructor(global, smbXsrv_session_global_destructor);

	/*
	 * Here we just randomly try the whole 32-bit space
	 *
	 * We use just 32-bit, because we want to reuse the
	 * ID for SRVSVC.
	 */
	for (i = 0; i < UINT32_MAX; i++) {
		bool is_free = false;
		bool was_free = false;
		uint32_t id;

		if (i >= min_tries && last_free != 0) {
			id = last_free;
		} else {
			id = generate_random();
		}
		if (id == 0) {
			id++;
		}
		if (id == UINT32_MAX) {
			id--;
		}

		global->db_rec = smbXsrv_session_global_fetch_locked(db, id,
								     mem_ctx);
		if (global->db_rec == NULL) {
			talloc_free(global);
			return NT_STATUS_INSUFFICIENT_RESOURCES;
		}

		smbXsrv_session_global_verify_record(global->db_rec,
						     &is_free,
						     &was_free,
						     NULL, NULL);

		if (!is_free) {
			TALLOC_FREE(global->db_rec);
			continue;
		}

		if (!was_free && i < min_tries) {
			/*
			 * The session_id is free now,
			 * but was not free before.
			 *
			 * This happens if a smbd crashed
			 * and did not cleanup the record.
			 *
			 * If this is one of our first tries,
			 * then we try to find a real free one.
			 */
			if (last_free == 0) {
				last_free = id;
			}
			TALLOC_FREE(global->db_rec);
			continue;
		}

		global->session_global_id = id;

		*_global = global;
		return NT_STATUS_OK;
	}

	/* should not be reached */
	talloc_free(global);
	return NT_STATUS_INTERNAL_ERROR;
}
static NTSTATUS smbd_smb2_bind_auth_return(struct smbXsrv_session *session,
					   struct smbXsrv_session_auth0 **_auth,
					   struct smbd_smb2_request *smb2req,
					   struct auth_session_info *session_info,
					   uint16_t *out_session_flags,
					   uint64_t *out_session_id)
{
	NTSTATUS status;
	struct smbXsrv_session *x = session;
	struct smbXsrv_session_auth0 *auth = *_auth;
	struct smbXsrv_connection *xconn = smb2req->xconn;
	struct smbXsrv_channel_global0 *c = NULL;
	uint8_t session_key[16];
	size_t i;
	struct _derivation {
		DATA_BLOB label;
		DATA_BLOB context;
	};
	struct {
		struct _derivation signing;
	} derivation = { };
	bool ok;

	*_auth = NULL;

	if (xconn->protocol >= PROTOCOL_SMB3_10) {
		struct smbXsrv_preauth *preauth;
		struct _derivation *d;
		DATA_BLOB p;
		struct hc_sha512state sctx;

		preauth = talloc_move(smb2req, &auth->preauth);

		samba_SHA512_Init(&sctx);
		samba_SHA512_Update(&sctx, preauth->sha512_value,
				    sizeof(preauth->sha512_value));
		for (i = 1; i < smb2req->in.vector_count; i++) {
			samba_SHA512_Update(&sctx,
					    smb2req->in.vector[i].iov_base,
					    smb2req->in.vector[i].iov_len);
		}
		samba_SHA512_Final(preauth->sha512_value, &sctx);

		p = data_blob_const(preauth->sha512_value,
				    sizeof(preauth->sha512_value));

		d = &derivation.signing;
		d->label = data_blob_string_const_null("SMBSigningKey");
		d->context = p;

	} else if (xconn->protocol >= PROTOCOL_SMB2_24) {
		struct _derivation *d;

		d = &derivation.signing;
		d->label = data_blob_string_const_null("SMB2AESCMAC");
		d->context = data_blob_string_const_null("SmbSign");
	}

	status = smbXsrv_session_find_channel(session, xconn, &c);
	if (!NT_STATUS_IS_OK(status)) {
		return status;
	}

	ok = security_token_is_sid(session_info->security_token,
			&x->global->auth_session_info->security_token->sids[0]);
	if (!ok) {
		return NT_STATUS_NOT_SUPPORTED;
	}

	if (session_info->session_key.length == 0) {
		/* See [MS-SMB2] 3.3.5.2.4 for the return code. */
		return NT_STATUS_NOT_SUPPORTED;
	}

	ZERO_STRUCT(session_key);
	memcpy(session_key, session_info->session_key.data,
	       MIN(session_info->session_key.length, sizeof(session_key)));

	c->signing_key = data_blob_talloc(x->global,
					  session_key,
					  sizeof(session_key));
	if (c->signing_key.data == NULL) {
		ZERO_STRUCT(session_key);
		return NT_STATUS_NO_MEMORY;
	}

	if (xconn->protocol >= PROTOCOL_SMB2_24) {
		struct _derivation *d = &derivation.signing;

		smb2_key_derivation(session_key, sizeof(session_key),
				    d->label.data, d->label.length,
				    d->context.data, d->context.length,
				    c->signing_key.data);
	}
	ZERO_STRUCT(session_key);

	TALLOC_FREE(auth);
	status = smbXsrv_session_update(session);
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(0, ("smb2: Failed to update session for vuid=%llu - %s\n",
			  (unsigned long long)session->compat->vuid,
			  nt_errstr(status)));
		return NT_STATUS_LOGON_FAILURE;
	}

	*out_session_id = session->global->session_wire_id;

	return NT_STATUS_OK;
}