base.c

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/*
 *   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 2 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, write to the Free Software
 *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */
 
/**
 * $Id: 081f116cfa4b120119cebb92965e2bb273684649 $
 * @file src/process/crl/base.c
 * @brief State machine for CRL coordinator thread
 *
 * @copyright 2026 Network RADIUS SAS (legal@networkradius.com)
 */
#ifdef WITH_TLS
#include <freeradius-devel/crl/crl.h>
#include <freeradius-devel/io/coord_pair.h>
#include <freeradius-devel/server/main_config.h>
#include <freeradius-devel/server/protocol.h>
#include <freeradius-devel/tls/strerror.h>
#include <freeradius-devel/tls/utils.h>
#include <freeradius-devel/unlang/interpret.h>
#include <freeradius-devel/util/debug.h>
 
#include <openssl/x509.h>
#include <openssl/x509v3.h>
#include <openssl/asn1.h>
 
static fr_dict_t const *dict_crl;
static fr_dict_t const *dict_freeradius;
 
extern fr_dict_autoload_t process_crl_dict[];
fr_dict_autoload_t process_crl_dict[] = {
        { .out = &dict_crl, .proto = "crl" },
        { .out = &dict_freeradius, .proto = "freeradius" },
        DICT_AUTOLOAD_TERMINATOR
};
 
static fr_dict_attr_t const *attr_packet_type;
static fr_dict_attr_t const *attr_crl_cdp_url;
static fr_dict_attr_t const *attr_base_crl;
static fr_dict_attr_t const *attr_crl_data;
static fr_dict_attr_t const *attr_crl_num;
static fr_dict_attr_t const *attr_delta_crl;
static fr_dict_attr_t const *attr_last_update;
static fr_dict_attr_t const *attr_next_update;
static fr_dict_attr_t const *attr_worker_id;
 
extern fr_dict_attr_autoload_t process_crl_dict_attr[];
fr_dict_attr_autoload_t process_crl_dict_attr[] = {
        { .out = &attr_packet_type, .name = "Packet-Type", .type = FR_TYPE_UINT32, .dict = &dict_crl },
        { .out = &attr_crl_cdp_url, .name = "CDP-URL", .type = FR_TYPE_STRING, .dict = &dict_crl },
        { .out = &attr_base_crl, .name = "Base-CRL", .type = FR_TYPE_STRING, .dict = &dict_crl },
        { .out = &attr_crl_data, .name = "CRL-Data", .type = FR_TYPE_OCTETS, .dict = &dict_crl },
        { .out = &attr_crl_num, .name = "CRL-Num", .type = FR_TYPE_UINT64, .dict = &dict_crl },
        { .out = &attr_delta_crl, .name = "Delta-CRL", .type = FR_TYPE_STRING, .dict = &dict_crl },
        { .out = &attr_last_update, .name = "Last-Update", .type = FR_TYPE_DATE, .dict = &dict_crl },
        { .out = &attr_next_update, .name = "Next-Update", .type = FR_TYPE_DATE, .dict = &dict_crl },
        { .out = &attr_worker_id, .name = "Worker-Id", .type = FR_TYPE_INT32, .dict = &dict_freeradius },
 
        DICT_AUTOLOAD_TERMINATOR
};
 
typedef struct {
        uint64_t        nothing;                // so that the next field isn't at offset 0
 
        CONF_SECTION    *crl_fetch;
        CONF_SECTION    *fetch_ok;
        CONF_SECTION    *fetch_fail;
        CONF_SECTION    *do_not_respond;
} process_crl_sections_t;
 
typedef struct {
        fr_rb_tree_t                    crls;           //!< Fetched CRL data.
        fr_dlist_head_t                 fetching;       //!< List of CRLs currently being fetched.
} process_crl_mutable_t;
 
typedef struct {
        process_crl_sections_t          sections;       //!< Pointers to various config sections
                                                        ///< we need to execute
 
        fr_time_delta_t                 force_refresh;                  //!< Force refresh of CRLs after this time
        bool                            force_refresh_is_set;
        fr_time_delta_t                 force_delta_refresh;            //!< Force refresh of delta CRLs after this time
        bool                            force_delta_refresh_is_set;
        fr_time_delta_t                 early_refresh;                  //!< Time interval before nextUpdate to refresh
        fr_time_delta_t                 retry_delay;                    //!< Delay between retries of failed refreshes.
        char const                      *ca_file;                       //!< File containing certs for verifying CRL signatures.
        char const                      *ca_path;                       //!< Directory containing certs for verifying CRL signatures.
 
        bool                            allow_expired;                  //!< Will CRLs be accepted after nextUpdate
        bool                            allow_not_yet_valid;            //!< Will CRLs be accepted before lastUpdate
 
        X509_STORE                      *verify_store;  //!< Store of certificates to verify CRL signatures;
 
        process_crl_mutable_t           *mutable;       //!< Mutable data
} process_crl_t;
 
typedef struct {
        fr_event_list_t                 *el;            //!< Event list for CRL refresh events.
} process_thread_crl_t;
 
static const conf_parser_t config[] = {
        { FR_CONF_OFFSET_IS_SET("force_refresh", FR_TYPE_TIME_DELTA, 0, process_crl_t, force_refresh) },
        { FR_CONF_OFFSET_IS_SET("force_delta_refresh", FR_TYPE_TIME_DELTA, 0, process_crl_t, force_delta_refresh) },
        { FR_CONF_OFFSET("early_refresh", process_crl_t, early_refresh) },
        { FR_CONF_OFFSET("retry_delay", process_crl_t, retry_delay), .dflt = "30s" },
        { FR_CONF_OFFSET("ca_file", process_crl_t, ca_file) },
        { FR_CONF_OFFSET("ca_path", process_crl_t, ca_path) },
        { FR_CONF_OFFSET("allow_expired", process_crl_t, allow_expired) },
        { FR_CONF_OFFSET("allow_not_yet_valid", process_crl_t, allow_not_yet_valid) },
        CONF_PARSER_TERMINATOR
};
 
typedef enum {
        CRL_TYPE_BASE,
        CRL_TYPE_DELTA
} crl_type_t;
 
/** A single CRL in the list of CRLs
 */
typedef struct {
        char const                      *cdp_url;               //!< The URL of the CRL.
        crl_type_t                      type;                   //!< What type of CRL is this.
        uint8_t                         *crl_data;              //!< The CRL data.
        time_t                          last_update;            //!< Last update value extracted from the CRL.
        time_t                          next_update;            //!< Next update value extracted from the CRL.
        ASN1_INTEGER                    *crl_num;               //!< The CRL number.
        fr_rb_node_t                    node;                   //!< The node in the tree of CRLs;
        fr_time_t                       refresh;                //!< Refresh time of the CRL.
        union {
                fr_value_box_list_t     delta_urls;             //!< URLs from which a delta CRL can be retrieved
                char const              *base_url;              //!< Base URL if this is a delta
        };
        process_crl_t                   *inst;                  //!< Module instance this entry is associated with.
        fr_coord_pair_t                 *coord_pair;            //!< The coord_pair which requested this CRL.
        fr_timer_t                      *ev;                    //!< Timer event for renewal.
} crl_entry_t;
 
/** An entry in the list of CRLs currently being fetched.
 */
typedef struct {
        char const                      *cdp_url;               //!< URL being fetched.
        bool                            *workers;               //!< True for each worker waiting for a response.
        fr_dlist_t                      entry;                  //!< Entry in list of CRLs being fetched.
} crl_fetch_t;
 
/** An entry in the list of CRL requests pending a currently running fetch
 */
typedef struct {
        request_t                       *request;
        int32_t                         worker_id;
        fr_dlist_t                      entry;
} crl_pending_request_t;
 
/** Compare two CRLs in the list of entries by URL
 */
static int8_t crl_cmp(void const *a, void const *b)
{
        crl_entry_t     const   *crl_a = (crl_entry_t const *)a;
        crl_entry_t     const   *crl_b = (crl_entry_t const *)b;
 
        return CMP(strcmp(crl_a->cdp_url,  crl_b->cdp_url), 0);
}
 
/** Resume context for CRL requests */
typedef struct {
        unlang_result_t         result;                 //!< Where process section results are written to
        int32_t                 worker_id;              //!< The worker which sent the data leading to this request.
        char const              *cdp_url;               //!< The URL of the CRL being requested.
        crl_entry_t             *crl_entry;             //!< The existing instance a CRL, if previously fetched.
        crl_entry_t             *base_crl;              //!< The base CRL a delta CRL is related to.
        bool                    cached;                 //!< This is a cached response.
        bool                    refresh;                //!< Is this a refresh request.
} process_crl_rctx_t;
 
#define FR_CRL_PACKET_CODE_VALID(_code) (((_code) > 0) && ((_code) < FR_CRL_CODE_MAX))
#define FR_CRL_PROCESS_CODE_VALID(_code) (FR_CRL_PACKET_CODE_VALID(_code) || (_code == FR_CRL_DO_NOT_RESPOND))
 
#define PROCESS_PACKET_TYPE             fr_crl_packet_code_t
#define PROCESS_CODE_MAX                FR_CRL_CODE_MAX
#define PROCESS_CODE_DO_NOT_RESPOND     FR_CRL_DO_NOT_RESPOND
#define PROCESS_PACKET_CODE_VALID       FR_CRL_PROCESS_CODE_VALID
#define PROCESS_INST                    process_crl_t
#define PROCESS_RCTX                    process_crl_rctx_t
 
#include <freeradius-devel/server/process.h>
 
RECV(crl_fetch);
RECV(crl_refresh);
 
/** Common setup used by both CRL-Fetch and CRL-Refresh
 */
static unlang_action_t fetch_setup_common(unlang_result_t *p_result, module_ctx_t const *mctx, request_t *request,
                                          fr_pair_t *vp, process_crl_rctx_t *rctx)
{
        process_crl_t           *inst = talloc_get_type_abort(mctx->mi->data, process_crl_t);
        crl_fetch_t             *fetch;
 
        /*
         *      Check to see if we're already fetching this URL.  If so, record
         *      that this worker wants the reply, and just Do Not Respond.
         */
        fr_dlist_foreach(&inst->mutable->fetching, crl_fetch_t, fetching) {
                if (strcmp(fetching->cdp_url, vp->vp_strvalue) == 0) {
                        if (rctx->worker_id >= 0) fetching->workers[rctx->worker_id] = true;
                        RDEBUG2("CRL already being fetched");
                        return CALL_SEND_TYPE(FR_CRL_DO_NOT_RESPOND);
                }
        }
 
        /*
         *      Cache the URI / Base CRL incase the pair gets altered / deleted in the process section.
         */
        rctx->cdp_url = talloc_bstrdup(rctx, vp->vp_strvalue);
 
        vp = fr_pair_find_by_da(&request->request_pairs, NULL, attr_base_crl);
        if (vp) {
                crl_entry_t             find;
                find.cdp_url = vp->vp_strvalue;
                rctx->base_crl = fr_rb_find(&inst->mutable->crls, &find);
        }
 
        /*
         *      Record what CRL we're fetching in the list.
         */
        MEM(fetch = talloc(inst->mutable, crl_fetch_t));
        fetch->cdp_url = rctx->cdp_url;
        fetch->workers = talloc_zero_array(fetch, bool, main_config->max_workers);
        fr_dlist_insert_tail(&inst->mutable->fetching, fetch);
 
        return CALL_RECV(generic);
}
 
/** Build reply pairs from a CRL
 *
 * Pairs are marked as immutable to prevent changes when run through send Fetch-OK
 */
static int crl_build_reply(request_t *request, crl_entry_t *crl_entry)
{
        fr_pair_t       *vp;
 
        if (pair_update_reply(&vp, attr_crl_cdp_url) < 0) return -1;;
        fr_value_box_clear_value(&vp->data);
        fr_value_box_strdup(vp, &vp->data, NULL, crl_entry->cdp_url, false);
        fr_pair_immutable(vp);
 
        if (fr_pair_append_by_da(request->reply_ctx, &vp, &request->reply_pairs, attr_crl_num)< 0) return -1;
        ASN1_INTEGER_get_uint64(&vp->vp_uint64, crl_entry->crl_num);
        fr_pair_immutable(vp);
 
        if (crl_entry->type == CRL_TYPE_BASE) {
                fr_value_box_list_foreach(&crl_entry->delta_urls, delta_url) {
                        if (fr_pair_append_by_da(request->reply_ctx, &vp, &request->reply_pairs,
                                                 attr_delta_crl) < 0) return -1;
                        if (unlikely(fr_value_box_copy(vp, &vp->data, delta_url) < 0)) {
                                fr_pair_remove(&request->reply_pairs, vp);
                                talloc_free(vp);
                        }
                        fr_pair_immutable(vp);
                }
        }
 
        if (fr_pair_append_by_da(request->reply_ctx, &vp, &request->reply_pairs, attr_last_update) < 0) return -1;
        vp->vp_date = fr_unix_time_from_sec(crl_entry->last_update);
        fr_pair_immutable(vp);
 
        if (fr_pair_append_by_da(request->reply_ctx, &vp, &request->reply_pairs, attr_next_update) < 0) return -1;
        vp->vp_date = fr_unix_time_from_sec(crl_entry->next_update);
        fr_pair_immutable(vp);
 
        return 0;
}
 
/** CRL-Fetch packets are sent from workers to the coordinator.
 *
 * They can reply with cached data if it exists, otherwise a fetch will
 * be initiated.
 *
 * Replies will always be sent back.
 */
RECV(crl_fetch)
{
        process_crl_t           *inst = talloc_get_type_abort(mctx->mi->data, process_crl_t);
        process_crl_rctx_t      *rctx = talloc_get_type_abort(mctx->rctx, process_crl_rctx_t);
        fr_pair_t               *vp = fr_pair_find_by_da(&request->request_pairs, NULL, attr_worker_id);
        crl_entry_t             find, *crl_entry;
 
        if (!vp) return UNLANG_ACTION_FAIL;
        rctx->worker_id = vp->vp_int32;
 
        vp = fr_pair_find_by_da(&request->request_pairs, NULL, attr_crl_cdp_url);
        if (!vp) return UNLANG_ACTION_FAIL;
 
        find.cdp_url = vp->vp_strvalue;
        rctx->crl_entry = crl_entry = fr_rb_find(&inst->mutable->crls, &find);
 
        /*
         *      If we found the data, send it back without running the process section as long as it's not expired.
         */
        if (crl_entry && (inst->allow_expired || fr_time_gt(fr_time_from_sec(crl_entry->next_update),
                                                            fr_time_from_sec(time(NULL))))) {
                if (fr_pair_append_by_da(request->reply_ctx, &vp, &request->reply_pairs,
                                         attr_crl_data) < 0) return CALL_SEND_TYPE(FR_CRL_FETCH_FAIL);
                fr_value_box_memdup_buffer(vp, &vp->data, NULL, crl_entry->crl_data, false);
                fr_pair_set_immutable(vp);
 
                if (crl_build_reply(request, crl_entry) < 0) return CALL_SEND_TYPE(FR_CRL_FETCH_FAIL);
 
                rctx->cached = true;
                return CALL_SEND_TYPE(FR_CRL_FETCH_OK);
        }
 
        return fetch_setup_common(p_result, mctx, request, vp, rctx);
}
 
/** CRL-Refresh packets are generated within the coordinator by refresh timer events
 *
 * Fetching of CRL data is run through the recv Fetch-CRL process section.
 * Data will only be sent to workers if the refresh fetched a newer CRL.
 */
RECV(crl_refresh) {
        process_crl_t           *inst = talloc_get_type_abort(mctx->mi->data, process_crl_t);
        process_crl_rctx_t      *rctx = talloc_get_type_abort(mctx->rctx, process_crl_rctx_t);
        fr_pair_t               *vp = fr_pair_find_by_da(&request->request_pairs, NULL, attr_crl_cdp_url);
        crl_entry_t             find;
 
        if (!vp) return UNLANG_ACTION_FAIL;
 
        find.cdp_url = vp->vp_strvalue;
        rctx->crl_entry = fr_rb_find(&inst->mutable->crls, &find);
        if (rctx->crl_entry) rctx->refresh = true;
 
        return fetch_setup_common(p_result, mctx, request, vp, rctx);
}
 
/** Tidy up CRL entries when freeing.
 */
static int _crl_entry_free(crl_entry_t *to_free)
{
        if (to_free->crl_num) ASN1_INTEGER_free(to_free->crl_num);
 
        /*
         *      Ensure the entry is no-longer in the tree.
         */
        if (fr_rb_node_inline_in_tree(&to_free->node)) fr_rb_remove(&to_free->inst->mutable->crls, to_free);
 
        /*
         *      If the entry referenced deltas, those must be removed as well.
         */
        if ((to_free->type == CRL_TYPE_BASE) && fr_value_box_list_initialised(&to_free->delta_urls)) {
                fr_value_box_list_foreach(&to_free->delta_urls, delta) {
                        crl_entry_t     find, *delta_crl;
 
                        find.cdp_url = delta->vb_strvalue;
                        delta_crl = fr_rb_find(&to_free->inst->mutable->crls, &find);
                        if (!delta_crl) continue;
 
                        fr_rb_remove(&to_free->inst->mutable->crls, delta_crl);
                        talloc_free(delta_crl);
                }
        }
 
        return 0;
}
 
/** Event callback to trigger the refresh of a CRL
 */
static void crl_refresh_event(fr_timer_list_t *tl, fr_time_t now, void *uctx)
{
        crl_entry_t     *crl_entry = talloc_get_type_abort(uctx, crl_entry_t);
        fr_pair_list_t  list;
        fr_pair_t       *vp;
        TALLOC_CTX      *local = talloc_new(NULL);
 
        DEBUG2("Refreshing CRL from CDP %s", crl_entry->cdp_url);
 
        fr_pair_list_init(&list);
        fr_pair_list_append_by_da(local, vp, &list, attr_packet_type, (uint32_t)FR_CRL_CRL_REFRESH, false);
        if (!vp) {
        fail:
                talloc_free(local);
                return;
        }
 
        if (fr_pair_append_by_da(local, &vp, &list, attr_crl_cdp_url) < 0) goto fail;
        fr_value_box_strdup(vp, &vp->data, NULL, crl_entry->cdp_url, false);
 
        if (crl_entry->type == CRL_TYPE_DELTA) {
                if (fr_pair_append_by_da(local, &vp, &list, attr_base_crl) < 0) goto fail;
                fr_value_box_strdup(vp, &vp->data, NULL, crl_entry->cdp_url, false);
        }
 
        if (fr_coord_pair_coord_request_start(crl_entry->coord_pair, &list, now) < 0) {
                ERROR("Failed to initialise CRL refresh request");
                if (fr_timer_in(crl_entry, tl, &crl_entry->ev, crl_entry->inst->retry_delay, false,
                                crl_refresh_event, crl_entry) <0) {
                        ERROR("Failed to set timer to retry CRL refresh");
                }
        }
 
        talloc_free(local);
}
 
static inline void crl_fetching_entry_remove(fr_dlist_head_t *fetching, char const *cdp_url) {
        fr_dlist_foreach(fetching, crl_fetch_t, fetch) {
                if (strcmp(fetch->cdp_url, cdp_url) == 0) {
                        fr_dlist_remove(fetching, fetch);
                        talloc_free(fetch);
                        return;
                }
        }
}
 
RESUME(crl_fetch)
{
        process_crl_t           *inst = talloc_get_type_abort(mctx->mi->data, process_crl_t);
        process_thread_crl_t    *thread = talloc_get_type_abort(mctx->thread, process_thread_crl_t);
        process_crl_rctx_t      *rctx = talloc_get_type_abort(mctx->rctx, process_crl_rctx_t);
        crl_entry_t             *crl_entry = NULL;
        fr_pair_t               *crl_data;
        uint8_t const           *data;
        X509_CRL                *crl;
        X509_STORE_CTX          *verify_ctx = NULL;
        X509_OBJECT             *xobj;
        EVP_PKEY                *pkey;
        STACK_OF(DIST_POINT)    *dps;
        int                     i;
        fr_time_t               now = fr_time();
        fr_time_delta_t         refresh_delta;
 
        switch (RESULT_RCODE) {
        case RLM_MODULE_USER_SECTION_REJECT:
                return CALL_RESUME(recv_generic);
        default:
                break;
        }
 
        /*
         *      If no CRL data was returned, that's a failure
         */
        crl_data = fr_pair_find_by_da(&request->reply_pairs, NULL, attr_crl_data);
        if (!crl_data) {
                RERROR("No %s found", attr_crl_data->name);
                return CALL_SEND_TYPE(FR_CRL_FETCH_FAIL);
        }
        fr_pair_immutable(crl_data);
 
        /*
         *      Parse the CRL data and verify it is correctly signed
         */
        data = crl_data->vp_octets;
        crl = d2i_X509_CRL(NULL, (const unsigned char **)&data, crl_data->vp_size);
        if (!crl) {
                fr_tls_strerror_printf("Failed to parse CRL from %s", rctx->cdp_url);
                return CALL_SEND_TYPE(FR_CRL_FETCH_FAIL);
        }
 
        verify_ctx = X509_STORE_CTX_new();
        if (!verify_ctx || !X509_STORE_CTX_init(verify_ctx, inst->verify_store, NULL, NULL)) {
                fr_tls_strerror_printf("Error initialising X509 store");
        error:
                if (verify_ctx) X509_STORE_CTX_free(verify_ctx);
                RPERROR("Error verifying CRL");
                X509_CRL_free(crl);
                talloc_free(crl_entry);
                return CALL_SEND_TYPE(FR_CRL_FETCH_FAIL);
        }
 
        xobj = X509_STORE_CTX_get_obj_by_subject(verify_ctx, X509_LU_X509, X509_CRL_get_issuer(crl));
        if (!xobj) {
                fr_tls_strerror_printf("CRL issuer certificate not in trusted store");
                goto error;
        }
        pkey = X509_get_pubkey(X509_OBJECT_get0_X509(xobj));
        X509_OBJECT_free(xobj);
        if (!pkey) {
                fr_tls_strerror_printf("Error getting CRL issuer public key");
                goto error;
        }
        i = X509_CRL_verify(crl, pkey);
        EVP_PKEY_free(pkey);
 
        if (i < 0) {
                fr_tls_strerror_printf("Could not verify CRL signature");
                goto error;
        }
        if (i == 0) {
                fr_tls_strerror_printf("CRL certificate signature failed");
                goto error;
        }
 
        /*
         *      Now we have a verified CRL, start building the entry for the global list
         */
        MEM(crl_entry = talloc_zero(inst->mutable, crl_entry_t));
        crl_entry->inst = inst;
 
        /*
         *      If we're passed a base_crl, then this is a delta.
         */
        crl_entry->type = rctx->base_crl ? CRL_TYPE_DELTA : CRL_TYPE_BASE;
        talloc_set_destructor(crl_entry, _crl_entry_free);
 
        if (fr_tls_utils_asn1time_to_epoch(&crl_entry->next_update, X509_CRL_get0_nextUpdate(crl)) < 0) {
                RPERROR("Failed to parse nextUpdate from CRL");
                goto error;
        }
 
        if (!inst->allow_expired && fr_time_lt(fr_time_from_sec(crl_entry->next_update),
                                               fr_time_from_sec(time(NULL)))) {
                RPERROR("Fetched CRL expired at %pV", fr_box_time(fr_time_from_sec(crl_entry->next_update)));
                goto error;
        }
 
        crl_entry->crl_num = X509_CRL_get_ext_d2i(crl, NID_crl_number, &i, NULL);
        if (!crl_entry->crl_num) {
                fr_tls_strerror_printf("Missing CRL number");
                goto error;
        }
 
        /*
         *      If there is existing data for this CRL, the it should only be updated if the number has increased.
         */
        if (rctx->crl_entry) {
                if (ASN1_INTEGER_cmp(crl_entry->crl_num, rctx->crl_entry->crl_num) == 0) {
                        uint64_t new_num;
                        ASN1_INTEGER_get_uint64(&new_num, crl_entry->crl_num);
                        RDEBUG3("Refresh returned the same CRL number (%"PRIu64") as the existing entry", new_num);
                        goto use_old;
                }
                if (ASN1_INTEGER_cmp(crl_entry->crl_num, rctx->crl_entry->crl_num) < 0) {
                        uint64_t old_num, new_num;
                        ASN1_INTEGER_get_uint64(&old_num, rctx->crl_entry->crl_num);
                        ASN1_INTEGER_get_uint64(&new_num, crl_entry->crl_num);
                        RERROR("Got CRL number %"PRIu64" which is less than current number %"PRIu64,
                               new_num, old_num);
                use_old:
                        crl_fetching_entry_remove(&inst->mutable->fetching, rctx->cdp_url);
                        talloc_free(crl_entry);
                        crl_entry = rctx->crl_entry;
 
                        if (rctx->refresh) {
                                /*
                                 *      A refresh which didn't produce updated data means noop.
                                 */
                                rctx->result.rcode = RLM_MODULE_NOOP;
                        } else {
                                /*
                                 *      CRL-Fetch requests expect a response.
                                 */
                                if (crl_build_reply(request, crl_entry) < 0) goto error;
                        }
                        goto timer;
                }
 
                /*
                 *      The fetched entry data is newer, free the old entry.
                 *      This will also remove it from the tree and clear any
                 *      related deltas.
                 */
                TALLOC_FREE(rctx->crl_entry);
        }
 
        /*
         *      The fetched CRL is now validated and newer than the old
         *      entry, complete building the entry.
         */
        crl_entry->cdp_url = talloc_bstrdup(crl_entry, rctx->cdp_url);
        crl_entry->crl_data = talloc_typed_memdup(crl_entry, crl_data->vp_octets, crl_data->vp_length);
        crl_entry->coord_pair = fr_coord_pair_request_coord_pair(request);
 
        /*
         *      If this is a delta check it relates to the correct base.
         */
        if (crl_entry->type == CRL_TYPE_DELTA) {
                ASN1_INTEGER *base_num = X509_CRL_get_ext_d2i(crl, NID_delta_crl, &i, NULL);
 
#ifdef __clang_analyzer__
                /*
                 *      type is set to CRL_TYPE_DELTA by the presence of a base_crl
                 *      but the analysers don't detect this.
                 */
                if (unlikely(!rctx->base_crl)) goto error;
#endif
                fr_assert(rctx->base_crl);
                if (!base_num) {
                        RERROR("Delta CRL missing Delta CRL Indicator extension");
                        goto error;
                }
                if (ASN1_INTEGER_cmp(base_num, rctx->base_crl->crl_num) > 0) {
                        uint64_t delta_base, crl_num;
                        ASN1_INTEGER_get_uint64(&delta_base, base_num);
                        ASN1_INTEGER_get_uint64(&crl_num, rctx->base_crl->crl_num);
                        RERROR("Delta CRL referrs to base CRL number %"PRIu64", current base is %"PRIu64,
                               delta_base, crl_num);
                        ASN1_INTEGER_free(base_num);
                        goto error;
                }
                ASN1_INTEGER_free(base_num);
                if (ASN1_INTEGER_cmp(crl_entry->crl_num, rctx->base_crl->crl_num) < 0) {
                        uint64_t delta_num, crl_num;
                        ASN1_INTEGER_get_uint64(&delta_num, crl_entry->crl_num);
                        ASN1_INTEGER_get_uint64(&crl_num, rctx->base_crl->crl_num);
                        RERROR("Delta CRL number %"PRIu64" is less than base CRL number %"PRIu64, delta_num, crl_num);
                        goto error;
                }
                crl_entry->base_url = talloc_strdup(crl_entry, rctx->base_crl->cdp_url);
        }
 
        if (fr_tls_utils_asn1time_to_epoch(&crl_entry->last_update, X509_CRL_get0_lastUpdate(crl)) < 0) {
                RPERROR("Failed to parse lastUpdate from CRL");
                goto error;
        }
 
        if (!inst->allow_not_yet_valid && fr_time_gt(fr_time_from_sec(crl_entry->last_update),
                                                     fr_time_from_sec(time(NULL)))) {
                RPERROR("Fetched CRL is not valid until %pV", fr_box_time(fr_time_from_sec(crl_entry->last_update)));
                goto error;
        }
 
        /*
         *      Check if this CRL has a Freshest CRL extension - the list of URIs to get deltas from
         */
        if ((crl_entry->type == CRL_TYPE_BASE) && (dps = X509_CRL_get_ext_d2i(crl, NID_freshest_crl, NULL, NULL))) {
                DIST_POINT              *dp;
                STACK_OF(GENERAL_NAME)  *names;
                GENERAL_NAME            *name;
                int                     j;
                fr_value_box_t          *vb;
 
                fr_value_box_list_init(&crl_entry->delta_urls);
                for (i = 0; i < sk_DIST_POINT_num(dps); i++) {
                        dp = sk_DIST_POINT_value(dps, i);
                        names = dp->distpoint->name.fullname;
                        for (j = 0; j < sk_GENERAL_NAME_num(names); j++) {
                                name = sk_GENERAL_NAME_value(names, j);
                                if (name->type != GEN_URI) continue;
                                MEM(vb = fr_value_box_alloc_null(crl_entry));
                                fr_value_box_bstrndup(vb, vb, NULL,
                                                      (char const *)ASN1_STRING_get0_data(name->d.uniformResourceIdentifier),
                                                      ASN1_STRING_length(name->d.uniformResourceIdentifier), true);
                                RDEBUG3("CRL references delta URI %pV", vb);
                                fr_value_box_list_insert_tail(&crl_entry->delta_urls, vb);
                        }
                }
                CRL_DIST_POINTS_free(dps);
 
                /*
                 *      If the CRL has a delta then fetch it.  An updated CRL means the
                 *      delta must be updated or it's invalid as it will point to the wrong
                 *      version of the base CRL.
                 */
                if (fr_value_box_list_num_elements(&crl_entry->delta_urls) > 0) {
                        fr_pair_list_t  list;
                        fr_pair_t       *vp;
                        TALLOC_CTX      *local = talloc_new(NULL);
 
                        fr_pair_list_init(&list);
                        fr_pair_list_append_by_da(local, vp, &list, attr_packet_type, (uint32_t)FR_CRL_CRL_REFRESH, false);
                        if (!vp) goto free_local;
 
                        fr_value_box_list_foreach(&crl_entry->delta_urls, delta) {
                                if (fr_pair_append_by_da(local, &vp, &list, attr_crl_cdp_url) < 0) goto free_local;
                                if (unlikely(fr_value_box_copy(vp, &vp->data, delta) < 0)) goto free_local;
                        }
 
                        if (fr_pair_append_by_da(local, &vp, &list, attr_base_crl) < 0) goto free_local;
                        if (unlikely(fr_value_box_strdup(vp, &vp->data, NULL, rctx->cdp_url,
                                                         false) < 0)) goto free_local;
 
                        if (fr_coord_pair_coord_request_start(crl_entry->coord_pair, &list, now) < 0) {
                                RERROR("Failed to start fetch of delta CRL");
                        }
 
                free_local:
                        talloc_free(local);
                }
        }
 
        if (!fr_rb_insert(&inst->mutable->crls, crl_entry)) {
                RERROR("Failed storing CRL");
                goto error;
        }
 
        if (crl_build_reply(request, crl_entry) < 0) goto error;
 
timer:
        /*
         *      Setup a timer to refresh the CRL
         */
        crl_entry->refresh = fr_time_from_sec(crl_entry->next_update);
        refresh_delta = fr_time_delta_sub(fr_time_sub(crl_entry->refresh, now), inst->early_refresh);
        if (rctx->base_crl && inst->force_delta_refresh_is_set) {
                if (fr_time_delta_cmp(refresh_delta, inst->force_delta_refresh)) refresh_delta = inst->force_delta_refresh;
        } else {
                if (inst->force_refresh_is_set &&
                    (fr_time_delta_cmp(refresh_delta, inst->force_refresh) > 0)) refresh_delta = inst->force_refresh;
        }
 
        /*
         *      A negative expiry time will occur if a refresh fails to fetch a newer CRL
         *      or the CRL has already expired. In that case use retry_delay to rate limit retrys.
         */
        if (fr_time_delta_isneg(refresh_delta)) refresh_delta = inst->retry_delay;
 
        RDEBUG2("CRL from %s will refresh in %pVs", rctx->cdp_url, fr_box_time_delta(refresh_delta));
 
        if (fr_timer_in(crl_entry, thread->el->tl, &crl_entry->ev, refresh_delta, false, crl_refresh_event, crl_entry) <0) {
                RERROR("Failed to set timer to refresh CRL");
        }
 
        X509_STORE_CTX_free(verify_ctx);
        X509_CRL_free(crl);
 
        return CALL_RESUME(recv_generic);
}
 
RESUME_FLAG(send_crl_ok, UNUSED,)
{
        process_crl_t           *inst = talloc_get_type_abort(mctx->mi->data, process_crl_t);
        process_crl_rctx_t      *rctx = talloc_get_type_abort(mctx->rctx, process_crl_rctx_t);
 
        /*
         *      Remove the fetching entry.  We use broadcast for the reply after
         *      a fetch so no need to individually send to workers.
         */
        crl_fetching_entry_remove(&inst->mutable->fetching, rctx->cdp_url);
 
        if (rctx->cached) {
                /*
                 *      Cached replies are only sent to the worker which requested the data.
                 */
                RDEBUG3("Sending cached CRL to worker %d", rctx->worker_id);
                fr_coord_to_worker_reply_send(request, rctx->worker_id);
        } else {
                /*
                 *      Successful update of a CRL is broadcast to all clients.
                 */
                RDEBUG3("Sending updated CRL to all workers");
                fr_coord_to_worker_reply_broadcast(request);
        }
 
        return UNLANG_ACTION_CALCULATE_RESULT;
}
 
RESUME_FLAG(send_crl_fail, UNUSED,)
{
        process_crl_t           *inst = talloc_get_type_abort(mctx->mi->data, process_crl_t);
        process_thread_crl_t    *thread = talloc_get_type_abort(mctx->thread, process_thread_crl_t);
        process_crl_rctx_t      *rctx = talloc_get_type_abort(mctx->rctx, process_crl_rctx_t);
        fr_pair_t               *vp;
 
        if (rctx->refresh) {
                crl_fetching_entry_remove(&inst->mutable->fetching, rctx->cdp_url);
 
                /*
                 *      Set up retry of failed refresh.
                 */
                RDEBUG2("Refresh of CRL from %s will retry in %pVs", rctx->cdp_url, fr_box_time_delta(inst->retry_delay));
 
                if (fr_timer_in(rctx->crl_entry, thread->el->tl, &rctx->crl_entry->ev, inst->retry_delay,
                                false, crl_refresh_event, rctx->crl_entry) <0) {
                        RERROR("Failed to set timer to retry CRL fetch");
                }
 
                /*
                 *      Refresh requests are local to the coordinator, so there
                 *      is nothing to send back on a failure, unless the CRL has
                 *      expired and expired CRLs are not allowed.
                 */
                if (inst->allow_expired || fr_time_gt(fr_time_from_sec(rctx->crl_entry->next_update),
                                                      fr_time_from_sec(time(NULL)))) {
                        return UNLANG_ACTION_CALCULATE_RESULT;
                }
 
                /*
                 *      A refresh failed on an expired CRL, notify all workers with a CRL-Expire reply.
                 */
                fr_pair_list_free(&request->reply_pairs);
                if (fr_pair_append_by_da(request->reply_ctx, &vp, &request->reply_pairs,
                                         attr_packet_type) < 0) RETURN_UNLANG_FAIL;
                vp->vp_uint32 = FR_CRL_CRL_EXPIRE;
 
                if (fr_pair_append_by_da(request->reply_ctx, &vp, &request->reply_pairs,
                                         attr_crl_cdp_url) < 0) RETURN_UNLANG_FAIL;
                fr_value_box_strdup(vp, &vp->data, NULL, rctx->cdp_url, false);
 
                fr_coord_to_worker_reply_broadcast(request);
 
                return UNLANG_ACTION_CALCULATE_RESULT;
        }
 
        /*
         *      The fetch failed, ensure we don't send CRL data back
         */
        fr_pair_delete_by_da(&request->reply_pairs, attr_crl_data);
 
        if (pair_update_reply(&vp, attr_crl_cdp_url) < 0) RETURN_UNLANG_FAIL;
        fr_value_box_strdup(vp, &vp->data, NULL, rctx->cdp_url, false);
 
        RDEBUG3("Sending fail to worker %d", rctx->worker_id);
        fr_coord_to_worker_reply_send(request, rctx->worker_id);
 
        /*
         *      If any other workers were waiting for this CRL, send them
         *      the failure as well.
         */
        fr_dlist_foreach(&inst->mutable->fetching, crl_fetch_t, fetch) {
                if (strcmp(fetch->cdp_url, rctx->cdp_url) == 0) {
                        uint32_t        i;
                        fr_dlist_remove(&inst->mutable->fetching, fetch);
                        for (i = 0; i < main_config->max_workers; i++) {
                                if (fetch->workers[i]) {
                                        fr_coord_to_worker_reply_send(request, i);
                                        RDEBUG3("Sending fail to worker %d", i);
                                }
                        }
                        talloc_free(fetch);
                        break;
                }
        }
 
        return UNLANG_ACTION_CALCULATE_RESULT;
}
 
static unlang_action_t mod_process(unlang_result_t *p_result, module_ctx_t const *mctx, request_t *request)
{
        fr_process_state_t const *state;
 
        PROCESS_TRACE;
 
        (void)talloc_get_type_abort_const(mctx->mi->data, process_crl_t);
        fr_assert(FR_CRL_PACKET_CODE_VALID(request->packet->code));
 
        request->component = "crl";
        request->module = NULL;
        fr_assert(request->proto_dict == dict_crl);
 
        UPDATE_STATE(packet);
 
        if (!state->recv) {
                REDEBUG("Invalid packet type (%u)", request->packet->code);
                RETURN_UNLANG_FAIL;
        }
 
        log_request_pair_list(L_DBG_LVL_1, request, NULL, &request->request_pairs, NULL);
 
        return state->recv(p_result, mctx, request);
}
 
static int mod_instantiate(module_inst_ctx_t const *mctx)
{
        process_crl_t   *inst = talloc_get_type_abort(mctx->mi->data, process_crl_t);
 
        MEM(inst->mutable = talloc_zero(NULL, process_crl_mutable_t));
 
        fr_rb_inline_init(&inst->mutable->crls, crl_entry_t, node, crl_cmp, NULL);
        fr_dlist_init(&inst->mutable->fetching, crl_fetch_t, entry);
 
        inst->verify_store = X509_STORE_new();
        if (!X509_STORE_load_locations(inst->verify_store, inst->ca_file, inst->ca_path)) {
                cf_log_err(mctx->mi->conf, "Failed reading Trusted root CA file \"%s\" and path \"%s\"",
                           inst->ca_file, inst->ca_path);
                return -1;
        }
 
        X509_STORE_set_purpose(inst->verify_store, X509_PURPOSE_SSL_CLIENT);
 
        return 0;
}
 
static int mod_detach(module_detach_ctx_t const *mctx)
{
        process_crl_t   *inst = talloc_get_type_abort(mctx->mi->data, process_crl_t);
 
        if (inst->verify_store) X509_STORE_free(inst->verify_store);
        talloc_free(inst->mutable);
 
        return 0;
}
 
static int mod_thread_instantiate(module_thread_inst_ctx_t const *mctx)
{
        process_thread_crl_t    *t = talloc_get_type_abort(mctx->thread, process_thread_crl_t);
 
        t->el = mctx->el;
        return 0;
}
 
static fr_process_state_t const process_state[] = {
        /*
         *      Fetch a CRL
         */
        [ FR_CRL_CRL_FETCH ] = {
                .packet_type = {
                        [RLM_MODULE_OK]         = FR_CRL_FETCH_OK,
                        [RLM_MODULE_UPDATED]    = FR_CRL_FETCH_OK,
                        [RLM_MODULE_FAIL]       = FR_CRL_FETCH_FAIL,
                        [RLM_MODULE_INVALID]    = FR_CRL_FETCH_FAIL,
                        [RLM_MODULE_REJECT]     = FR_CRL_FETCH_FAIL,
                        [RLM_MODULE_DISALLOW]   = FR_CRL_FETCH_FAIL,
                        [RLM_MODULE_NOTFOUND]   = FR_CRL_FETCH_FAIL,
                        [RLM_MODULE_NOOP]       = FR_CRL_FETCH_OK,
                        [RLM_MODULE_TIMEOUT]    = FR_CRL_DO_NOT_RESPOND
                },
                .default_rcode = RLM_MODULE_NOOP,
                .recv = recv_crl_fetch,
                .resume = resume_crl_fetch,
                .section_offset = offsetof(process_crl_sections_t, crl_fetch),
        },
        [ FR_CRL_CRL_REFRESH ] = {
                .packet_type = {
                        [RLM_MODULE_OK]         = FR_CRL_FETCH_OK,
                        [RLM_MODULE_UPDATED]    = FR_CRL_FETCH_OK,
                        [RLM_MODULE_FAIL]       = FR_CRL_FETCH_FAIL,
                        [RLM_MODULE_INVALID]    = FR_CRL_FETCH_FAIL,
                        [RLM_MODULE_REJECT]     = FR_CRL_FETCH_FAIL,
                        [RLM_MODULE_DISALLOW]   = FR_CRL_FETCH_FAIL,
                        [RLM_MODULE_NOTFOUND]   = FR_CRL_FETCH_FAIL,
                        [RLM_MODULE_NOOP]       = FR_CRL_DO_NOT_RESPOND,
                        [RLM_MODULE_TIMEOUT]    = FR_CRL_DO_NOT_RESPOND
                },
                .default_rcode = RLM_MODULE_NOOP,
                .recv = recv_crl_refresh,
                .resume = resume_crl_fetch,
                .section_offset = offsetof(process_crl_sections_t, crl_fetch),
        },
        [ FR_CRL_FETCH_OK ] = {
                .packet_type = {
                        [RLM_MODULE_FAIL]       = FR_CRL_FETCH_FAIL,
                        [RLM_MODULE_INVALID]    = FR_CRL_FETCH_FAIL,
                        [RLM_MODULE_REJECT]     = FR_CRL_FETCH_FAIL,
                        [RLM_MODULE_DISALLOW]   = FR_CRL_FETCH_FAIL,
                        [RLM_MODULE_TIMEOUT]    = FR_CRL_DO_NOT_RESPOND
                },
                .default_rcode = RLM_MODULE_NOOP,
                .result_rcode = RLM_MODULE_OK,
                .send = send_generic,
                .resume = resume_send_crl_ok,
                .section_offset = offsetof(process_crl_sections_t, fetch_ok),
        },
        [ FR_CRL_FETCH_FAIL ] = {
                .packet_type = {
                        [RLM_MODULE_FAIL]       = FR_CRL_FETCH_FAIL,
                        [RLM_MODULE_INVALID]    = FR_CRL_FETCH_FAIL,
                        [RLM_MODULE_REJECT]     = FR_CRL_FETCH_FAIL,
                        [RLM_MODULE_DISALLOW]   = FR_CRL_FETCH_FAIL,
                        [RLM_MODULE_TIMEOUT]    = FR_CRL_DO_NOT_RESPOND
                },
                .default_rcode = RLM_MODULE_NOOP,
                .result_rcode = RLM_MODULE_REJECT,
                .send = send_generic,
                .resume = resume_send_crl_fail,
                .section_offset = offsetof(process_crl_sections_t, fetch_fail),
        },
        [ FR_CRL_DO_NOT_RESPOND ] = {
                .packet_type = {
                        [RLM_MODULE_NOOP]       = FR_CRL_DO_NOT_RESPOND,
                        [RLM_MODULE_OK]         = FR_CRL_DO_NOT_RESPOND,
                        [RLM_MODULE_UPDATED]    = FR_CRL_DO_NOT_RESPOND,
                        [RLM_MODULE_HANDLED]    = FR_CRL_DO_NOT_RESPOND,
 
                        [RLM_MODULE_NOTFOUND]   = FR_CRL_DO_NOT_RESPOND,
                        [RLM_MODULE_FAIL]       = FR_CRL_DO_NOT_RESPOND,
                        [RLM_MODULE_INVALID]    = FR_CRL_DO_NOT_RESPOND,
                        [RLM_MODULE_REJECT]     = FR_CRL_DO_NOT_RESPOND,
                        [RLM_MODULE_DISALLOW]   = FR_CRL_DO_NOT_RESPOND,
                        [RLM_MODULE_TIMEOUT]    = FR_CRL_DO_NOT_RESPOND
                },
                .default_rcode = RLM_MODULE_NOOP,
                .result_rcode = RLM_MODULE_HANDLED,
                .send = send_generic,
                .resume = resume_send_generic,
                .section_offset = offsetof(process_crl_sections_t, do_not_respond),
        }
};
 
static virtual_server_compile_t compile_list[] = {
        {
                .section = SECTION_NAME("recv", "CRL-Fetch"),
                .actions = &mod_actions_authenticate,
                .offset = PROCESS_CONF_OFFSET(crl_fetch),
        },
        {
                .section = SECTION_NAME("send", "Fetch-OK"),
                .actions = &mod_actions_authenticate,
                .offset = PROCESS_CONF_OFFSET(fetch_ok),
        },
        {
                .section = SECTION_NAME("send", "Fetch-Fail"),
                .actions = &mod_actions_authenticate,
                .offset = PROCESS_CONF_OFFSET(fetch_fail),
        },
        {
                .section = SECTION_NAME("send", "Do-Not-Respond"),
                .actions = &mod_actions_authenticate,
                .offset = PROCESS_CONF_OFFSET(do_not_respond),
        },
 
        COMPILE_TERMINATOR
};
 
extern fr_process_module_t process_crl;
fr_process_module_t process_crl = {
        .common = {
                .magic                  = MODULE_MAGIC_INIT,
                .name                   = "crl",
                .config                 = config,
                MODULE_INST(process_crl_t),
                MODULE_RCTX(process_crl_rctx_t),
                .instantiate            = mod_instantiate,
                .detach                 = mod_detach,
                MODULE_THREAD_INST(process_thread_crl_t),
                .thread_instantiate     = mod_thread_instantiate
        },
        .process        = mod_process,
        .compile_list   = compile_list,
        .dict           = &dict_crl,
        .packet_type    = &attr_packet_type
};
#endif