/* Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ /* * Security options etc. * * Module derived from code originally written by Rob McCool * */ #include "apr_strings.h" #include "apr_network_io.h" #include "apr_md5.h" #include "apr_hash.h" #define APR_WANT_STRFUNC #define APR_WANT_BYTEFUNC #include "apr_want.h" #include "ap_config.h" #include "ap_provider.h" #include "httpd.h" #include "http_core.h" #include "http_config.h" #include "http_log.h" #include "http_protocol.h" #include "http_request.h" #include "mod_auth.h" #if APR_HAVE_NETINET_IN_H #include #endif /* * To save memory if the same subnets are used in hundres of vhosts, we store * each subnet only once and use this temporary hash to find it again. */ static apr_hash_t *parsed_subnets; static apr_ipsubnet_t *localhost_v4; #if APR_HAVE_IPV6 static apr_ipsubnet_t *localhost_v6; #endif static int in_domain(const char *domain, const char *what) { int dl = strlen(domain); int wl = strlen(what); if ((wl - dl) >= 0) { if (strcasecmp(domain, &what[wl - dl]) != 0) { return 0; } /* Make sure we matched an *entire* subdomain --- if the user * said 'allow from good.com', we don't want people from nogood.com * to be able to get in. */ if (wl == dl) { return 1; /* matched whole thing */ } else { return (domain[0] == '.' || what[wl - dl - 1] == '.'); } } else { return 0; } } static const char *ip_parse_config(cmd_parms *cmd, const char *require_line, const void **parsed_require_line) { const char *t, *w; int count = 0; apr_ipsubnet_t **ip; apr_pool_t *ptemp = cmd->temp_pool; apr_pool_t *p = cmd->pool; /* The 'ip' provider will allow the configuration to specify a list of ip addresses to check rather than a single address. This is different from the previous host based syntax. */ t = require_line; while ((w = ap_getword_conf(ptemp, &t)) && w[0]) count++; if (count == 0) return "'require ip' requires an argument"; ip = apr_pcalloc(p, sizeof(apr_ipsubnet_t *) * (count + 1)); *parsed_require_line = ip; t = require_line; while ((w = ap_getword_conf(ptemp, &t)) && w[0]) { char *addr = apr_pstrdup(ptemp, w); char *mask; apr_status_t rv; if (parsed_subnets && (*ip = apr_hash_get(parsed_subnets, w, APR_HASH_KEY_STRING)) != NULL) { /* we already have parsed this subnet */ ip++; continue; } if ((mask = ap_strchr(addr, '/'))) *mask++ = '\0'; rv = apr_ipsubnet_create(ip, addr, mask, p); if(APR_STATUS_IS_EINVAL(rv)) { /* looked nothing like an IP address */ return apr_psprintf(p, "ip address '%s' appears to be invalid", w); } else if (rv != APR_SUCCESS) { return apr_psprintf(p, "ip address '%s' appears to be invalid: %pm", w, &rv); } if (parsed_subnets) apr_hash_set(parsed_subnets, w, APR_HASH_KEY_STRING, *ip); ip++; } return NULL; } static authz_status ip_check_authorization(request_rec *r, const char *require_line, const void *parsed_require_line) { /* apr_ipsubnet_test should accept const but doesn't */ apr_ipsubnet_t **ip = (apr_ipsubnet_t **)parsed_require_line; while (*ip) { if (apr_ipsubnet_test(*ip, r->useragent_addr)) return AUTHZ_GRANTED; ip++; } /* authz_core will log the require line and the result at DEBUG */ return AUTHZ_DENIED; } static authz_status host_check_authorization(request_rec *r, const char *require_line, const void *parsed_require_line) { const char *t, *w; const char *remotehost = NULL; int remotehost_is_ip; remotehost = ap_get_useragent_host(r, REMOTE_DOUBLE_REV, &remotehost_is_ip); if ((remotehost == NULL) || remotehost_is_ip) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01753) "access check of '%s' to %s failed, reason: unable to get the " "remote host name", require_line, r->uri); } else { const char *err = NULL; const ap_expr_info_t *expr = parsed_require_line; const char *require; require = ap_expr_str_exec(r, expr, &err); if (err) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02593) "authz_host authorize: require host: Can't " "evaluate require expression: %s", err); return AUTHZ_DENIED; } /* The 'host' provider will allow the configuration to specify a list of host names to check rather than a single name. This is different from the previous host based syntax. */ t = require; /* '#' is not a valid hostname character and admin could * specify 'Require host localhost# Add example.com later'. We * should not grant access to 'example.com' in that case. */ w = ap_strchr_c(t, '#'); if (w) { if (w == t) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(10120) "authz_host authorize: dubious empty " "'Require host %s' with only comment", t); return AUTHZ_DENIED; } ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(10121) "authz_host authorize: ignoring comment in " "'Require host %s'", t); /* Truncate the string at the #. */ t = apr_pstrmemdup(r->pool, t, w - t); } while ((w = ap_getword_conf(r->pool, &t)) && w[0]) { if (in_domain(w, remotehost)) { return AUTHZ_GRANTED; } } } /* authz_core will log the require line and the result at DEBUG */ return AUTHZ_DENIED; } static authz_status forward_dns_check_authorization(request_rec *r, const char *require_line, const void *parsed_require_line) { const char *err = NULL; const ap_expr_info_t *expr = parsed_require_line; const char *require, *t; char *w; /* the require line is an expression, which is evaluated now. */ require = ap_expr_str_exec(r, expr, &err); if (err) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(03354) "authz_host authorize: require forward-dns: " "Can't evaluate require expression: %s", err); return AUTHZ_DENIED; } /* tokenize expected list of names */ t = require; while ((w = ap_getword_conf(r->pool, &t)) && w[0]) { apr_sockaddr_t *sa; apr_status_t rv; char *hash_ptr; /* stop on apache configuration file comments */ if ((hash_ptr = ap_strchr(w, '#'))) { if (hash_ptr == w) { break; } *hash_ptr = '\0'; } /* does the client ip match one of the names? */ rv = apr_sockaddr_info_get(&sa, w, APR_UNSPEC, 0, 0, r->pool); if (rv == APR_SUCCESS) { while (sa) { int match = apr_sockaddr_equal(sa, r->useragent_addr); ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(03355) "access check for %s as '%s': %s", r->useragent_ip, w, match? "yes": "no"); if (match) { return AUTHZ_GRANTED; } sa = sa->next; } } else { ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(03356) "No sockaddr info for \"%s\"", w); } /* stop processing, we are in a comment */ if (hash_ptr) { break; } } return AUTHZ_DENIED; } static authz_status local_check_authorization(request_rec *r, const char *require_line, const void *parsed_require_line) { if ( apr_sockaddr_equal(r->connection->local_addr, r->useragent_addr) || apr_ipsubnet_test(localhost_v4, r->useragent_addr) #if APR_HAVE_IPV6 || apr_ipsubnet_test(localhost_v6, r->useragent_addr) #endif ) { return AUTHZ_GRANTED; } return AUTHZ_DENIED; } static const char *host_parse_config(cmd_parms *cmd, const char *require_line, const void **parsed_require_line) { const char *expr_err = NULL; ap_expr_info_t *expr; expr = ap_expr_parse_cmd(cmd, require_line, AP_EXPR_FLAG_STRING_RESULT, &expr_err, NULL); if (expr_err) return apr_pstrcat(cmd->temp_pool, "Cannot parse expression in require line: ", expr_err, NULL); *parsed_require_line = expr; return NULL; } static const authz_provider authz_ip_provider = { &ip_check_authorization, &ip_parse_config, }; static const authz_provider authz_host_provider = { &host_check_authorization, &host_parse_config, }; static const authz_provider authz_forward_dns_provider = { &forward_dns_check_authorization, &host_parse_config, }; static const authz_provider authz_local_provider = { &local_check_authorization, NULL, }; static int authz_host_pre_config(apr_pool_t *p, apr_pool_t *plog, apr_pool_t *ptemp) { /* we only use this hash in the parse config phase, ptemp is enough */ parsed_subnets = apr_hash_make(ptemp); apr_ipsubnet_create(&localhost_v4, "127.0.0.0", "8", p); apr_hash_set(parsed_subnets, "127.0.0.0/8", APR_HASH_KEY_STRING, localhost_v4); #if APR_HAVE_IPV6 apr_ipsubnet_create(&localhost_v6, "::1", NULL, p); apr_hash_set(parsed_subnets, "::1", APR_HASH_KEY_STRING, localhost_v6); #endif return OK; } static int authz_host_post_config(apr_pool_t *p, apr_pool_t *plog, apr_pool_t *ptemp, server_rec *s) { /* make sure we don't use this during .htaccess parsing */ parsed_subnets = NULL; return OK; } static void register_hooks(apr_pool_t *p) { ap_hook_pre_config(authz_host_pre_config, NULL, NULL, APR_HOOK_MIDDLE); ap_hook_post_config(authz_host_post_config, NULL, NULL, APR_HOOK_MIDDLE); ap_register_auth_provider(p, AUTHZ_PROVIDER_GROUP, "ip", AUTHZ_PROVIDER_VERSION, &authz_ip_provider, AP_AUTH_INTERNAL_PER_CONF); ap_register_auth_provider(p, AUTHZ_PROVIDER_GROUP, "host", AUTHZ_PROVIDER_VERSION, &authz_host_provider, AP_AUTH_INTERNAL_PER_CONF); ap_register_auth_provider(p, AUTHZ_PROVIDER_GROUP, "forward-dns", AUTHZ_PROVIDER_VERSION, &authz_forward_dns_provider, AP_AUTH_INTERNAL_PER_CONF); ap_register_auth_provider(p, AUTHZ_PROVIDER_GROUP, "local", AUTHZ_PROVIDER_VERSION, &authz_local_provider, AP_AUTH_INTERNAL_PER_CONF); } AP_DECLARE_MODULE(authz_host) = { STANDARD20_MODULE_STUFF, NULL, /* dir config creater */ NULL, /* dir merger --- default is to override */ NULL, /* server config */ NULL, /* merge server config */ NULL, register_hooks /* register hooks */ };