diff options
Diffstat (limited to '')
-rw-r--r-- | modules/md/md_tailscale.c | 383 |
1 files changed, 383 insertions, 0 deletions
diff --git a/modules/md/md_tailscale.c b/modules/md/md_tailscale.c new file mode 100644 index 0000000..c8d2bad --- /dev/null +++ b/modules/md/md_tailscale.c @@ -0,0 +1,383 @@ +/* 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. + */ + +#include <assert.h> +#include <stdlib.h> + +#include <apr_lib.h> +#include <apr_strings.h> +#include <apr_hash.h> +#include <apr_uri.h> + +#include "md.h" +#include "md_crypt.h" +#include "md_json.h" +#include "md_http.h" +#include "md_log.h" +#include "md_result.h" +#include "md_reg.h" +#include "md_store.h" +#include "md_util.h" + +#include "md_tailscale.h" + +typedef struct { + apr_pool_t *pool; + md_proto_driver_t *driver; + const char *unix_socket_path; + md_t *md; + apr_array_header_t *chain; + md_pkey_t *pkey; +} ts_ctx_t; + +static apr_status_t ts_init(md_proto_driver_t *d, md_result_t *result) +{ + ts_ctx_t *ts_ctx; + apr_uri_t uri; + const char *ca_url; + apr_status_t rv = APR_SUCCESS; + + md_result_set(result, APR_SUCCESS, NULL); + ts_ctx = apr_pcalloc(d->p, sizeof(*ts_ctx)); + ts_ctx->pool = d->p; + ts_ctx->driver = d; + ts_ctx->chain = apr_array_make(d->p, 5, sizeof(md_cert_t *)); + + ca_url = (d->md->ca_urls && !apr_is_empty_array(d->md->ca_urls))? + APR_ARRAY_IDX(d->md->ca_urls, 0, const char*) : NULL; + if (!ca_url) { + ca_url = MD_TAILSCALE_DEF_URL; + } + rv = apr_uri_parse(d->p, ca_url, &uri); + if (APR_SUCCESS != rv) { + md_result_printf(result, rv, "error parsing CA URL `%s`", ca_url); + goto leave; + } + if (uri.scheme && uri.scheme[0] && strcmp("file", uri.scheme)) { + rv = APR_ENOTIMPL; + md_result_printf(result, rv, "non `file` URLs not supported, CA URL is `%s`", + ca_url); + goto leave; + } + if (uri.hostname && uri.hostname[0] && strcmp("localhost", uri.hostname)) { + rv = APR_ENOTIMPL; + md_result_printf(result, rv, "non `localhost` URLs not supported, CA URL is `%s`", + ca_url); + goto leave; + } + ts_ctx->unix_socket_path = uri.path; + d->baton = ts_ctx; + +leave: + return rv; +} + +static apr_status_t ts_preload_init(md_proto_driver_t *d, md_result_t *result) +{ + return ts_init(d, result); +} + +static apr_status_t ts_preload(md_proto_driver_t *d, + md_store_group_t load_group, md_result_t *result) +{ + apr_status_t rv; + md_t *md; + md_credentials_t *creds; + md_pkey_spec_t *pkspec; + apr_array_header_t *all_creds; + const char *name; + int i; + + name = d->md->name; + md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, d->p, "%s: preload start", name); + /* Load data from MD_SG_STAGING and save it into "load_group". + */ + if (APR_SUCCESS != (rv = md_load(d->store, MD_SG_STAGING, name, &md, d->p))) { + md_result_set(result, rv, "loading staged md.json"); + goto leave; + } + + /* tailscale generates one cert+key with key specification being whatever + * it chooses. Use the NULL spec here. + */ + all_creds = apr_array_make(d->p, 5, sizeof(md_credentials_t*)); + pkspec = NULL; + if (APR_SUCCESS != (rv = md_creds_load(d->store, MD_SG_STAGING, name, pkspec, &creds, d->p))) { + md_result_printf(result, rv, "loading staged credentials"); + goto leave; + } + if (!creds->chain) { + rv = APR_ENOENT; + md_result_printf(result, rv, "no certificate in staged credentials"); + goto leave; + } + if (APR_SUCCESS != (rv = md_check_cert_and_pkey(creds->chain, creds->pkey))) { + md_result_printf(result, rv, "certificate and private key do not match in staged credentials"); + goto leave; + } + APR_ARRAY_PUSH(all_creds, md_credentials_t*) = creds; + + md_result_activity_setn(result, "purging store tmp space"); + rv = md_store_purge(d->store, d->p, load_group, name); + if (APR_SUCCESS != rv) { + md_result_set(result, rv, NULL); + goto leave; + } + + md_result_activity_setn(result, "saving staged md/privkey/pubcert"); + if (APR_SUCCESS != (rv = md_save(d->store, d->p, load_group, md, 1))) { + md_result_set(result, rv, "writing md.json"); + goto leave; + } + + for (i = 0; i < all_creds->nelts; ++i) { + creds = APR_ARRAY_IDX(all_creds, i, md_credentials_t*); + if (APR_SUCCESS != (rv = md_creds_save(d->store, d->p, load_group, name, creds, 1))) { + md_result_printf(result, rv, "writing credentials #%d", i); + goto leave; + } + } + + md_result_set(result, APR_SUCCESS, "saved staged data successfully"); + +leave: + md_result_log(result, MD_LOG_DEBUG); + return rv; +} + +static apr_status_t rv_of_response(const md_http_response_t *res) +{ + switch (res->status) { + case 200: + return APR_SUCCESS; + case 400: + return APR_EINVAL; + case 401: /* sectigo returns this instead of 403 */ + case 403: + return APR_EACCES; + case 404: + return APR_ENOENT; + default: + return APR_EGENERAL; + } + return APR_SUCCESS; +} + +static apr_status_t on_get_cert(const md_http_response_t *res, void *baton) +{ + ts_ctx_t *ts_ctx = baton; + apr_status_t rv; + + rv = rv_of_response(res); + if (APR_SUCCESS != rv) goto leave; + apr_array_clear(ts_ctx->chain); + rv = md_cert_chain_read_http(ts_ctx->chain, ts_ctx->pool, res); + if (APR_SUCCESS != rv) goto leave; + +leave: + return rv; +} + +static apr_status_t on_get_key(const md_http_response_t *res, void *baton) +{ + ts_ctx_t *ts_ctx = baton; + apr_status_t rv; + + rv = rv_of_response(res); + if (APR_SUCCESS != rv) goto leave; + rv = md_pkey_read_http(&ts_ctx->pkey, ts_ctx->pool, res); + if (APR_SUCCESS != rv) goto leave; + +leave: + return rv; +} + +static apr_status_t ts_renew(md_proto_driver_t *d, md_result_t *result) +{ + const char *name, *domain, *url; + apr_status_t rv = APR_ENOENT; + ts_ctx_t *ts_ctx = d->baton; + md_http_t *http; + const md_pubcert_t *pubcert; + md_cert_t *old_cert, *new_cert; + int reset_staging = d->reset; + + /* "renewing" the certificate from tailscale. Since tailscale has its + * own ideas on when to do this, we can only inspect the certificate + * it gives us and see if it is different from the current one we have. + * (if we have any. first time, lacking a cert, any it gives us is + * considered as 'renewed'.) + */ + name = d->md->name; + md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, d->p, "%s: renewing cert", name); + + /* When not explicitly told to reset, we check the existing data. If + * it is incomplete or old, we trigger the reset for a clean start. */ + if (!reset_staging) { + md_result_activity_setn(result, "Checking staging area"); + rv = md_load(d->store, MD_SG_STAGING, d->md->name, &ts_ctx->md, d->p); + if (APR_SUCCESS == rv) { + /* So, we have a copy in staging, but is it a recent or an old one? */ + if (md_is_newer(d->store, MD_SG_DOMAINS, MD_SG_STAGING, d->md->name, d->p)) { + reset_staging = 1; + } + } + else if (APR_STATUS_IS_ENOENT(rv)) { + reset_staging = 1; + rv = APR_SUCCESS; + } + } + + if (reset_staging) { + md_result_activity_setn(result, "Resetting staging area"); + /* reset the staging area for this domain */ + rv = md_store_purge(d->store, d->p, MD_SG_STAGING, d->md->name); + md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, rv, d->p, + "%s: reset staging area", d->md->name); + if (APR_SUCCESS != rv && !APR_STATUS_IS_ENOENT(rv)) { + md_result_printf(result, rv, "resetting staging area"); + goto leave; + } + rv = APR_SUCCESS; + ts_ctx->md = NULL; + } + + if (!ts_ctx->md || !md_array_str_eq(ts_ctx->md->ca_urls, d->md->ca_urls, 1)) { + md_result_activity_printf(result, "Resetting staging for %s", d->md->name); + /* re-initialize staging */ + md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, d->p, "%s: setup staging", d->md->name); + md_store_purge(d->store, d->p, MD_SG_STAGING, d->md->name); + ts_ctx->md = md_copy(d->p, d->md); + rv = md_save(d->store, d->p, MD_SG_STAGING, ts_ctx->md, 0); + if (APR_SUCCESS != rv) { + md_result_printf(result, rv, "Saving MD information in staging area."); + md_result_log(result, MD_LOG_ERR); + goto leave; + } + } + + if (!ts_ctx->unix_socket_path) { + rv = APR_ENOTIMPL; + md_result_set(result, rv, "only unix sockets are supported for tailscale connections"); + goto leave; + } + + rv = md_util_is_unix_socket(ts_ctx->unix_socket_path, d->p); + if (APR_SUCCESS != rv) { + md_result_printf(result, rv, "tailscale socket not available, may not be up: %s", + ts_ctx->unix_socket_path); + goto leave; + } + + rv = md_http_create(&http, d->p, + apr_psprintf(d->p, "Apache mod_md/%s", MOD_MD_VERSION), + NULL); + if (APR_SUCCESS != rv) { + md_result_set(result, rv, "creating http context"); + goto leave; + } + md_http_set_unix_socket_path(http, ts_ctx->unix_socket_path); + + domain = (d->md->domains->nelts > 0)? + APR_ARRAY_IDX(d->md->domains, 0, const char*) : NULL; + if (!domain) { + rv = APR_EINVAL; + md_result_set(result, rv, "no domain names available"); + } + + url = apr_psprintf(d->p, "http://localhost/localapi/v0/cert/%s?type=crt", + domain); + rv = md_http_GET_perform(http, url, NULL, on_get_cert, ts_ctx); + if (APR_SUCCESS != rv) { + md_result_set(result, rv, "retrieving certificate from tailscale"); + goto leave; + } + if (ts_ctx->chain->nelts <= 0) { + rv = APR_ENOENT; + md_result_set(result, rv, "tailscale returned no certificates"); + goto leave; + } + + /* Got the key and the chain, is it new? */ + rv = md_reg_get_pubcert(&pubcert, d->reg,d->md, 0, d->p); + if (APR_SUCCESS == rv) { + old_cert = APR_ARRAY_IDX(pubcert->certs, 0, md_cert_t*); + new_cert = APR_ARRAY_IDX(ts_ctx->chain, 0, md_cert_t*); + if (md_certs_are_equal(old_cert, new_cert)) { + /* tailscale has not renewed the certificate, yet */ + rv = APR_ENOENT; + md_result_set(result, rv, "tailscale has not renewed the certificate yet"); + /* let's check this daily */ + md_result_delay_set(result, apr_time_now() + apr_time_from_sec(MD_SECS_PER_DAY)); + goto leave; + } + } + + /* We have a new certificate (or had none before). + * Get the key and store both in STAGING. + */ + url = apr_psprintf(d->p, "http://localhost/localapi/v0/cert/%s?type=key", + domain); + rv = md_http_GET_perform(http, url, NULL, on_get_key, ts_ctx); + if (APR_SUCCESS != rv) { + md_result_set(result, rv, "retrieving key from tailscale"); + goto leave; + } + + rv = md_pkey_save(d->store, d->p, MD_SG_STAGING, name, NULL, ts_ctx->pkey, 1); + if (APR_SUCCESS != rv) { + md_result_set(result, rv, "saving private key"); + goto leave; + } + + rv = md_pubcert_save(d->store, d->p, MD_SG_STAGING, name, + NULL, ts_ctx->chain, 1); + if (APR_SUCCESS != rv) { + md_result_printf(result, rv, "saving new certificate chain."); + goto leave; + } + + md_result_set(result, APR_SUCCESS, + "A new tailscale certificate has been retrieved successfully and can " + "be used. A graceful server restart is recommended."); + +leave: + md_result_log(result, MD_LOG_DEBUG); + return rv; +} + +static apr_status_t ts_complete_md(md_t *md, apr_pool_t *p) +{ + (void)p; + if (!md->ca_urls) { + md->ca_urls = apr_array_make(p, 3, sizeof(const char *)); + APR_ARRAY_PUSH(md->ca_urls, const char*) = MD_TAILSCALE_DEF_URL; + } + return APR_SUCCESS; +} + + +static md_proto_t TAILSCALE_PROTO = { + MD_PROTO_TAILSCALE, ts_init, ts_renew, + ts_preload_init, ts_preload, ts_complete_md, +}; + +apr_status_t md_tailscale_protos_add(apr_hash_t *protos, apr_pool_t *p) +{ + (void)p; + apr_hash_set(protos, MD_PROTO_TAILSCALE, sizeof(MD_PROTO_TAILSCALE)-1, &TAILSCALE_PROTO); + return APR_SUCCESS; +} |