diff --git a/changes/bug18456 b/changes/bug18456 new file mode 100644 index 0000000000..843c70a587 --- /dev/null +++ b/changes/bug18456 @@ -0,0 +1,6 @@ + o Major bugfixes (exit policies): + - Avoid disclosing exit outbound bind addresses, configured port bind + addresses, and local interface addresses in relay descriptors by + default under ExitPolicyRejectPrivate. Instead, only reject these + (otherwise unlisted) addresses if ExitPolicyRejectLocalInterfaces is set. + Fixes bug 18456; bugfix on 0.2.7.2-alpha. Patch by teor. diff --git a/doc/tor.1.txt b/doc/tor.1.txt index f42ac8cd03..b5d6e87683 100644 --- a/doc/tor.1.txt +++ b/doc/tor.1.txt @@ -1701,15 +1701,16 @@ is non-zero): used with accept6/reject6.) + + Private addresses are rejected by default (at the beginning of your exit - policy), along with any configured primary public IPv4 and IPv6 addresses, - and any public IPv4 and IPv6 addresses on any interface on the relay. + policy), along with any configured primary public IPv4 and IPv6 addresses. These private addresses are rejected unless you set the ExitPolicyRejectPrivate config option to 0. For example, once you've done that, you could allow HTTP to 127.0.0.1 and block all other connections to internal networks with "accept 127.0.0.1:80,reject private:\*", though that may also allow connections to your own computer that are addressed to its public (external) IP address. See RFC 1918 and RFC 3330 for more details - about internal and reserved IP address space. + + about internal and reserved IP address space. See + ExitPolicyRejectLocalInterfaces if you want to block every address on the + relay, even those that aren't advertised in the descriptor. + + This directive can be specified multiple times so you don't have to put it all on one line. + @@ -1739,16 +1740,23 @@ is non-zero): IPv4 and IPv6 addresses. [[ExitPolicyRejectPrivate]] **ExitPolicyRejectPrivate** **0**|**1**:: - Reject all private (local) networks, along with any configured public - IPv4 and IPv6 addresses, at the beginning of your exit policy. (This - includes the IPv4 and IPv6 addresses advertised by the relay, any - OutboundBindAddress, and the bind addresses of any port options, such as - ORPort and DirPort.) This also rejects any public IPv4 and IPv6 addresses - on any interface on the relay. (If IPv6Exit is not set, all IPv6 addresses - will be rejected anyway.) + Reject all private (local) networks, along with the relay's advertised + public IPv4 and IPv6 addresses, at the beginning of your exit policy. See above entry on ExitPolicy. (Default: 1) +[[ExitPolicyRejectLocalInterfaces]] **ExitPolicyRejectLocalInterfaces** **0**|**1**:: + Reject all IPv4 and IPv6 addresses that the relay knows about, at the + beginning of your exit policy. This includes any OutboundBindAddress, the + bind addresses of any port options, such as ControlPort or DNSPort, and any + public IPv4 and IPv6 addresses on any interface on the relay. (If IPv6Exit + is not set, all IPv6 addresses will be rejected anyway.) + See above entry on ExitPolicy. + This option is off by default, because it lists all public relay IP + addresses in the ExitPolicy, even those relay operators might prefer not + to disclose. + (Default: 0) + [[IPv6Exit]] **IPv6Exit** **0**|**1**:: If set, and we are an exit node, allow clients to use us for IPv6 traffic. (Default: 0) diff --git a/src/or/config.c b/src/or/config.c index a677f21955..64f270d911 100644 --- a/src/or/config.c +++ b/src/or/config.c @@ -244,6 +244,7 @@ static config_var_t option_vars_[] = { V(ExitNodes, ROUTERSET, NULL), V(ExitPolicy, LINELIST, NULL), V(ExitPolicyRejectPrivate, BOOL, "1"), + V(ExitPolicyRejectLocalInterfaces, BOOL, "0"), V(ExitPortStatistics, BOOL, "0"), V(ExtendAllowPrivateAddresses, BOOL, "0"), V(ExitRelay, AUTOBOOL, "auto"), @@ -4316,6 +4317,8 @@ options_transition_affects_descriptor(const or_options_t *old_options, old_options->ExitRelay != new_options->ExitRelay || old_options->ExitPolicyRejectPrivate != new_options->ExitPolicyRejectPrivate || + old_options->ExitPolicyRejectLocalInterfaces != + new_options->ExitPolicyRejectLocalInterfaces || old_options->IPv6Exit != new_options->IPv6Exit || !config_lines_eq(old_options->ORPort_lines, new_options->ORPort_lines) || diff --git a/src/or/control.c b/src/or/control.c index d3613d8d4f..ea7d7b7962 100644 --- a/src/or/control.c +++ b/src/or/control.c @@ -3025,7 +3025,7 @@ static const getinfo_item_t getinfo_items[] = { " ExitPolicyRejectPrivate."), ITEM("exit-policy/reject-private/relay", policies, "The relay-specific rules appended to the configured exit policy by" - " ExitPolicyRejectPrivate."), + " ExitPolicyRejectPrivate and/or ExitPolicyRejectLocalInterfaces."), ITEM("exit-policy/full", policies, "The entire exit policy of onion router"), ITEM("exit-policy/ipv4", policies, "IPv4 parts of exit policy"), ITEM("exit-policy/ipv6", policies, "IPv6 parts of exit policy"), diff --git a/src/or/main.c b/src/or/main.c index 4fc1498a98..48cf7aa144 100644 --- a/src/or/main.c +++ b/src/or/main.c @@ -2221,8 +2221,8 @@ ip_address_changed(int at_interface) { const or_options_t *options = get_options(); int server = server_mode(options); - int exit_reject_private = (server && options->ExitRelay - && options->ExitPolicyRejectPrivate); + int exit_reject_interfaces = (server && options->ExitRelay + && options->ExitPolicyRejectLocalInterfaces); if (at_interface) { if (! server) { @@ -2240,8 +2240,8 @@ ip_address_changed(int at_interface) } /* Exit relays incorporate interface addresses in their exit policies when - * ExitPolicyRejectPrivate is set */ - if (exit_reject_private || (server && !at_interface)) { + * ExitPolicyRejectLocalInterfaces is set */ + if (exit_reject_interfaces || (server && !at_interface)) { mark_my_descriptor_dirty("IP address changed"); } diff --git a/src/or/or.h b/src/or/or.h index ed799b98ff..af40cf7e81 100644 --- a/src/or/or.h +++ b/src/or/or.h @@ -3588,7 +3588,13 @@ typedef struct { /** Bitmask; derived from AllowInvalidNodes. */ invalid_router_usage_t AllowInvalid_; config_line_t *ExitPolicy; /**< Lists of exit policy components. */ - int ExitPolicyRejectPrivate; /**< Should we not exit to local addresses? */ + int ExitPolicyRejectPrivate; /**< Should we not exit to reserved private + * addresses, and our own published addresses? + */ + int ExitPolicyRejectLocalInterfaces; /**< Should we not exit to local + * interface addresses? + * Includes OutboundBindAddresses and + * configured ports. */ config_line_t *SocksPolicy; /**< Lists of socks policy components */ config_line_t *DirPolicy; /**< Lists of dir policy components */ /** Addresses to bind for listening for SOCKS connections. */ diff --git a/src/or/policies.c b/src/or/policies.c index 7ddebd6096..b8b5fe6f2d 100644 --- a/src/or/policies.c +++ b/src/or/policies.c @@ -1843,10 +1843,18 @@ policies_log_first_redundant_entry(const smartlist_t *policy) * * If ipv6_exit is false, prepend "reject *6:*" to the policy. * + * If configured_addresses contains addresses: + * - prepend entries that reject the addresses in this list. These may be the + * advertised relay addresses and/or the outbound bind addresses, + * depending on the ExitPolicyRejectPrivate and + * ExitPolicyRejectLocalInterfaces settings. * If rejectprivate is true: * - prepend "reject private:*" to the policy. - * - prepend entries that reject publicly routable addresses on this exit - * relay by calling policies_parse_exit_policy_reject_private + * If reject_interface_addresses is true: + * - prepend entries that reject publicly routable interface addresses on + * this exit relay by calling policies_parse_exit_policy_reject_private + * If reject_configured_port_addresses is true: + * - prepend entries that reject all configured port addresses * * If cfg doesn't end in an absolute accept or reject and if * add_default_policy is true, add the default exit @@ -1874,13 +1882,16 @@ policies_parse_exit_policy_internal(config_line_t *cfg, if (rejectprivate) { /* Reject IPv4 and IPv6 reserved private netblocks */ append_exit_policy_string(dest, "reject private:*"); - /* Reject IPv4 and IPv6 publicly routable addresses on this exit relay */ - policies_parse_exit_policy_reject_private( - dest, ipv6_exit, + } + + /* Consider rejecting IPv4 and IPv6 advertised relay addresses, outbound bind + * addresses, publicly routable addresses, and configured port addresses + * on this exit relay */ + policies_parse_exit_policy_reject_private(dest, ipv6_exit, configured_addresses, reject_interface_addresses, reject_configured_port_addresses); - } + if (parse_addr_policy(cfg, dest, -1)) return -1; @@ -1908,8 +1919,14 @@ policies_parse_exit_policy_internal(config_line_t *cfg, * If EXIT_POLICY_REJECT_PRIVATE bit is set in options: * - prepend an entry that rejects all destinations in all netblocks * reserved for private use. + * - prepend entries that reject the advertised relay addresses in + * configured_addresses + * If EXIT_POLICY_REJECT_LOCAL_INTERFACES bit is set in options: * - prepend entries that reject publicly routable addresses on this exit * relay by calling policies_parse_exit_policy_internal + * - prepend entries that reject the outbound bind addresses in + * configured_addresses + * - prepend entries that reject all configured port addresses * * If EXIT_POLICY_ADD_DEFAULT bit is set in options, append * default exit policy entries to result smartlist. @@ -1922,12 +1939,14 @@ policies_parse_exit_policy(config_line_t *cfg, smartlist_t **dest, int ipv6_enabled = (options & EXIT_POLICY_IPV6_ENABLED) ? 1 : 0; int reject_private = (options & EXIT_POLICY_REJECT_PRIVATE) ? 1 : 0; int add_default = (options & EXIT_POLICY_ADD_DEFAULT) ? 1 : 0; + int reject_local_interfaces = (options & + EXIT_POLICY_REJECT_LOCAL_INTERFACES) ? 1 : 0; return policies_parse_exit_policy_internal(cfg,dest,ipv6_enabled, reject_private, configured_addresses, - reject_private, - reject_private, + reject_local_interfaces, + reject_local_interfaces, add_default); } @@ -1993,6 +2012,7 @@ policies_copy_outbound_addresses_to_smartlist(smartlist_t *addr_list, * add it to the list of configured addresses. * - if ipv6_local_address is non-NULL, and not the null tor_addr_t, add it * to the list of configured addresses. + * If or_options->ExitPolicyRejectLocalInterfaces is true: * - if or_options->OutboundBindAddressIPv4_ is not the null tor_addr_t, add * it to the list of configured addresses. * - if or_options->OutboundBindAddressIPv6_ is not the null tor_addr_t, add @@ -2036,11 +2056,20 @@ policies_parse_exit_policy_from_options(const or_options_t *or_options, parser_cfg |= EXIT_POLICY_ADD_DEFAULT; } + if (or_options->ExitPolicyRejectLocalInterfaces) { + parser_cfg |= EXIT_POLICY_REJECT_LOCAL_INTERFACES; + } + /* Copy the configured addresses into the tor_addr_t* list */ - policies_copy_ipv4h_to_smartlist(configured_addresses, local_address); - policies_copy_addr_to_smartlist(configured_addresses, ipv6_local_address); - policies_copy_outbound_addresses_to_smartlist(configured_addresses, - or_options); + if (or_options->ExitPolicyRejectPrivate) { + policies_copy_ipv4h_to_smartlist(configured_addresses, local_address); + policies_copy_addr_to_smartlist(configured_addresses, ipv6_local_address); + } + + if (or_options->ExitPolicyRejectLocalInterfaces) { + policies_copy_outbound_addresses_to_smartlist(configured_addresses, + or_options); + } rv = policies_parse_exit_policy(or_options->ExitPolicy, result, parser_cfg, configured_addresses); @@ -2822,7 +2851,8 @@ getinfo_helper_policies(control_connection_t *conn, return -1; } - if (!options->ExitPolicyRejectPrivate) { + if (!options->ExitPolicyRejectPrivate && + !options->ExitPolicyRejectLocalInterfaces) { *answer = tor_strdup(""); return 0; } @@ -2831,16 +2861,22 @@ getinfo_helper_policies(control_connection_t *conn, smartlist_t *configured_addresses = smartlist_new(); /* Copy the configured addresses into the tor_addr_t* list */ - policies_copy_ipv4h_to_smartlist(configured_addresses, me->addr); - policies_copy_addr_to_smartlist(configured_addresses, &me->ipv6_addr); - policies_copy_outbound_addresses_to_smartlist(configured_addresses, - options); + if (options->ExitPolicyRejectPrivate) { + policies_copy_ipv4h_to_smartlist(configured_addresses, me->addr); + policies_copy_addr_to_smartlist(configured_addresses, &me->ipv6_addr); + } + + if (options->ExitPolicyRejectLocalInterfaces) { + policies_copy_outbound_addresses_to_smartlist(configured_addresses, + options); + } policies_parse_exit_policy_reject_private( - &private_policy_list, - options->IPv6Exit, - configured_addresses, - 1, 1); + &private_policy_list, + options->IPv6Exit, + configured_addresses, + options->ExitPolicyRejectLocalInterfaces, + options->ExitPolicyRejectLocalInterfaces); *answer = policy_dump_to_string(private_policy_list, 1, 1); addr_policy_list_free(private_policy_list); diff --git a/src/or/policies.h b/src/or/policies.h index aaa6fa0a4e..e134e686d2 100644 --- a/src/or/policies.h +++ b/src/or/policies.h @@ -18,9 +18,10 @@ */ #define POLICY_BUF_LEN 72 -#define EXIT_POLICY_IPV6_ENABLED (1 << 0) -#define EXIT_POLICY_REJECT_PRIVATE (1 << 1) -#define EXIT_POLICY_ADD_DEFAULT (1 << 2) +#define EXIT_POLICY_IPV6_ENABLED (1 << 0) +#define EXIT_POLICY_REJECT_PRIVATE (1 << 1) +#define EXIT_POLICY_ADD_DEFAULT (1 << 2) +#define EXIT_POLICY_REJECT_LOCAL_INTERFACES (1 << 3) typedef enum firewall_connection_t { FIREWALL_OR_CONNECTION = 0, diff --git a/src/test/test_policy.c b/src/test/test_policy.c index 14182af86b..a972bd5b29 100644 --- a/src/test/test_policy.c +++ b/src/test/test_policy.c @@ -1082,10 +1082,12 @@ test_policies_getinfo_helper_policies(void *arg) append_exit_policy_string(&mock_my_routerinfo.exit_policy, "reject *6:*"); mock_options.IPv6Exit = 1; - mock_options.ExitPolicyRejectPrivate = 1; tor_addr_from_ipv4h(&mock_options.OutboundBindAddressIPv4_, TEST_IPV4_ADDR); tor_addr_parse(&mock_options.OutboundBindAddressIPv6_, TEST_IPV6_ADDR); + mock_options.ExitPolicyRejectPrivate = 1; + mock_options.ExitPolicyRejectLocalInterfaces = 1; + rv = getinfo_helper_policies(NULL, "exit-policy/reject-private/relay", &answer, &errmsg); tt_assert(rv == 0); @@ -1093,6 +1095,36 @@ test_policies_getinfo_helper_policies(void *arg) tt_assert(strlen(answer) > 0); tor_free(answer); + mock_options.ExitPolicyRejectPrivate = 1; + mock_options.ExitPolicyRejectLocalInterfaces = 0; + + rv = getinfo_helper_policies(NULL, "exit-policy/reject-private/relay", + &answer, &errmsg); + tt_assert(rv == 0); + tt_assert(answer != NULL); + tt_assert(strlen(answer) > 0); + tor_free(answer); + + mock_options.ExitPolicyRejectPrivate = 0; + mock_options.ExitPolicyRejectLocalInterfaces = 1; + + rv = getinfo_helper_policies(NULL, "exit-policy/reject-private/relay", + &answer, &errmsg); + tt_assert(rv == 0); + tt_assert(answer != NULL); + tt_assert(strlen(answer) > 0); + tor_free(answer); + + mock_options.ExitPolicyRejectPrivate = 0; + mock_options.ExitPolicyRejectLocalInterfaces = 0; + + rv = getinfo_helper_policies(NULL, "exit-policy/reject-private/relay", + &answer, &errmsg); + tt_assert(rv == 0); + tt_assert(answer != NULL); + tt_assert(strlen(answer) == 0); + tor_free(answer); + rv = getinfo_helper_policies(NULL, "exit-policy/ipv4", &answer, &errmsg); tt_assert(rv == 0);