/*

 * Copyright 2019-2021 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the Apache License 2.0 (the "License").  You may not use

 * this file except in compliance with the License.  You can obtain a copy

 * in the file LICENSE in the source distribution or at

 * https://www.openssl.org/source/license.html

 */

#include <string.h>

#include <openssl/trace.h>

#include <openssl/err.h>

#include <openssl/conf.h>

#include <openssl/safestack.h>

#include <openssl/provider.h>

#include "internal/provider.h"

#include "internal/cryptlib.h"

#include "provider_local.h"

DEFINE_STACK_OF(OSSL_PROVIDER)

/* PROVIDER config module */

typedef struct {

    CRYPTO_RWLOCK *lock;

    STACK_OF(OSSL_PROVIDER) *activated_providers;

} PROVIDER_CONF_GLOBAL;

static void *prov_conf_ossl_ctx_new(OSSL_LIB_CTX *libctx)

{

    PROVIDER_CONF_GLOBAL *pcgbl = OPENSSL_zalloc(sizeof(*pcgbl));

    if (pcgbl == NULL)

        return NULL;

    pcgbl->lock = CRYPTO_THREAD_lock_new();

    if (pcgbl->lock == NULL) {

        OPENSSL_free(pcgbl);

        return NULL;

    }

    return pcgbl;

}

static void prov_conf_ossl_ctx_free(void *vpcgbl)

{

    PROVIDER_CONF_GLOBAL *pcgbl = vpcgbl;

    sk_OSSL_PROVIDER_pop_free(pcgbl->activated_providers,

                              ossl_provider_free);

    OSSL_TRACE(CONF, "Cleaned up providers\n");

    CRYPTO_THREAD_lock_free(pcgbl->lock);

    OPENSSL_free(pcgbl);

}

static const OSSL_LIB_CTX_METHOD provider_conf_ossl_ctx_method = {

    /* Must be freed before the provider store is freed */

    OSSL_LIB_CTX_METHOD_PRIORITY_2,

    prov_conf_ossl_ctx_new,

    prov_conf_ossl_ctx_free,

};

static const char *skip_dot(const char *name)

{

    const char *p = strchr(name, '.');

    if (p != NULL)

        return p + 1;

    return name;

}

static int provider_conf_params(OSSL_PROVIDER *prov,

                                OSSL_PROVIDER_INFO *provinfo,

                                const char *name, const char *value,

                                const CONF *cnf)

{

    STACK_OF(CONF_VALUE) *sect;

    int ok = 1;

    sect = NCONF_get_section(cnf, value);

    if (sect != NULL) {

        int i;

        char buffer[512];

        size_t buffer_len = 0;

        OSSL_TRACE1(CONF, "Provider params: start section %s\n", value);

        if (name != NULL) {

            OPENSSL_strlcpy(buffer, name, sizeof(buffer));

            OPENSSL_strlcat(buffer, ".", sizeof(buffer));

            buffer_len = strlen(buffer);

        }

        for (i = 0; i < sk_CONF_VALUE_num(sect); i++) {

            CONF_VALUE *sectconf = sk_CONF_VALUE_value(sect, i);

            if (buffer_len + strlen(sectconf->name) >= sizeof(buffer))

                return 0;

            buffer[buffer_len] = '\0';

            OPENSSL_strlcat(buffer, sectconf->name, sizeof(buffer));

            if (!provider_conf_params(prov, provinfo, buffer, sectconf->value,

                                      cnf))

                return 0;

        }

        OSSL_TRACE1(CONF, "Provider params: finish section %s\n", value);

    } else {

        OSSL_TRACE2(CONF, "Provider params: %s = %s\n", name, value);

        if (prov != NULL)

            ok = ossl_provider_add_parameter(prov, name, value);

        else

            ok = ossl_provider_info_add_parameter(provinfo, name, value);

    }

    return ok;

}

static int prov_already_activated(const char *name,

                                  STACK_OF(OSSL_PROVIDER) *activated)

{

    int i, max;

    if (activated == NULL)

        return 0;

    max = sk_OSSL_PROVIDER_num(activated);

    for (i = 0; i < max; i++) {

        OSSL_PROVIDER *tstprov = sk_OSSL_PROVIDER_value(activated, i);

        if (strcmp(OSSL_PROVIDER_get0_name(tstprov), name) == 0) {

            return 1;

        }

    }

    return 0;

}

static int provider_conf_load(OSSL_LIB_CTX *libctx, const char *name,

                              const char *value, const CONF *cnf)

{

    int i;

    STACK_OF(CONF_VALUE) *ecmds;

    int soft = 0;

    OSSL_PROVIDER *prov = NULL, *actual = NULL;

    const char *path = NULL;

    long activate = 0;

    int ok = 0;

    name = skip_dot(name);

    OSSL_TRACE1(CONF, "Configuring provider %s\n", name);

    /* Value is a section containing PROVIDER commands */

    ecmds = NCONF_get_section(cnf, value);

    if (!ecmds) {

        ERR_raise_data(ERR_LIB_CRYPTO, CRYPTO_R_PROVIDER_SECTION_ERROR,

                       "section=%s not found", value);

        return 0;

    }

    /* Find the needed data first */

    for (i = 0; i < sk_CONF_VALUE_num(ecmds); i++) {

        CONF_VALUE *ecmd = sk_CONF_VALUE_value(ecmds, i);

        const char *confname = skip_dot(ecmd->name);

        const char *confvalue = ecmd->value;

        OSSL_TRACE2(CONF, "Provider command: %s = %s\n",

                    confname, confvalue);

        /* First handle some special pseudo confs */

        /* Override provider name to use */

        if (strcmp(confname, "identity") == 0)

            name = confvalue;

        else if (strcmp(confname, "soft_load") == 0)

            soft = 1;

        /* Load a dynamic PROVIDER */

        else if (strcmp(confname, "module") == 0)

            path = confvalue;

        else if (strcmp(confname, "activate") == 0)

            activate = 1;

    }

    if (activate) {

        PROVIDER_CONF_GLOBAL *pcgbl

            = ossl_lib_ctx_get_data(libctx, OSSL_LIB_CTX_PROVIDER_CONF_INDEX,

                                    &provider_conf_ossl_ctx_method);

        if (pcgbl == NULL || !CRYPTO_THREAD_write_lock(pcgbl->lock)) {

            ERR_raise(ERR_LIB_CRYPTO, ERR_R_INTERNAL_ERROR);

            return 0;

        }

        if (!prov_already_activated(name, pcgbl->activated_providers)) {

            /*

            * There is an attempt to activate a provider, so we should disable

            * loading of fallbacks. Otherwise a misconfiguration could mean the

            * intended provider does not get loaded. Subsequent fetches could

            * then fallback to the default provider - which may be the wrong

            * thing.

            */

            if (!ossl_provider_disable_fallback_loading(libctx)) {

                CRYPTO_THREAD_unlock(pcgbl->lock);

                ERR_raise(ERR_LIB_CRYPTO, ERR_R_INTERNAL_ERROR);

                return 0;

            }

            prov = ossl_provider_find(libctx, name, 1);

            if (prov == NULL)

                prov = ossl_provider_new(libctx, name, NULL, 1);

            if (prov == NULL) {

                CRYPTO_THREAD_unlock(pcgbl->lock);

                if (soft)

                    ERR_clear_error();

                return 0;

            }

            if (path != NULL)

                ossl_provider_set_module_path(prov, path);

            ok = provider_conf_params(prov, NULL, NULL, value, cnf);

            if (ok) {

                if (!ossl_provider_activate(prov, 1, 0)) {

                    ok = 0;

                } else if (!ossl_provider_add_to_store(prov, &actual, 0)) {

                    ossl_provider_deactivate(prov, 1);

                    ok = 0;

                } else if (actual != prov

                           && !ossl_provider_activate(actual, 1, 0)) {

                    ossl_provider_free(actual);

                    ok = 0;

                } else {

                    if (pcgbl->activated_providers == NULL)

                        pcgbl->activated_providers = sk_OSSL_PROVIDER_new_null();

                    if (pcgbl->activated_providers == NULL

                        || !sk_OSSL_PROVIDER_push(pcgbl->activated_providers,

                                                  actual)) {

                        ossl_provider_deactivate(actual, 1);

                        ossl_provider_free(actual);

                        ok = 0;

                    } else {

                        ok = 1;

                    }

                }

            }

            if (!ok)

                ossl_provider_free(prov);

        }

        CRYPTO_THREAD_unlock(pcgbl->lock);

    } else {

        OSSL_PROVIDER_INFO entry;

        memset(&entry, 0, sizeof(entry));

        ok = 1;

        if (name != NULL) {

            entry.name = OPENSSL_strdup(name);

            if (entry.name == NULL) {

                ERR_raise(ERR_LIB_CRYPTO, ERR_R_MALLOC_FAILURE);

                ok = 0;

            }

        }

        if (ok && path != NULL) {

            entry.path = OPENSSL_strdup(path);

            if (entry.path == NULL) {

                ERR_raise(ERR_LIB_CRYPTO, ERR_R_MALLOC_FAILURE);

                ok = 0;

            }

        }

        if (ok)

            ok = provider_conf_params(NULL, &entry, NULL, value, cnf);

        if (ok && (entry.path != NULL || entry.parameters != NULL))

            ok = ossl_provider_info_add_to_store(libctx, &entry);

        if (!ok || (entry.path == NULL && entry.parameters == NULL)) {

            ossl_provider_info_clear(&entry);

        }

    }

    /*

     * Even if ok is 0, we still return success. Failure to load a provider is

     * not fatal. We want to continue to load the rest of the config file.

     */

    return 1;

}

static int provider_conf_init(CONF_IMODULE *md, const CONF *cnf)

{

    STACK_OF(CONF_VALUE) *elist;

    CONF_VALUE *cval;

    int i;

    OSSL_TRACE1(CONF, "Loading providers module: section %s\n",

                CONF_imodule_get_value(md));

    /* Value is a section containing PROVIDERs to configure */

    elist = NCONF_get_section(cnf, CONF_imodule_get_value(md));

    if (!elist) {

        ERR_raise(ERR_LIB_CRYPTO, CRYPTO_R_PROVIDER_SECTION_ERROR);

        return 0;

    }

    for (i = 0; i < sk_CONF_VALUE_num(elist); i++) {

        cval = sk_CONF_VALUE_value(elist, i);

        if (!provider_conf_load(NCONF_get0_libctx((CONF *)cnf),

                    cval->name, cval->value, cnf))

            return 0;

    }

    return 1;

}

void ossl_provider_add_conf_module(void)

{

    OSSL_TRACE(CONF, "Adding config module 'providers'\n");

    CONF_module_add("providers", provider_conf_init, NULL);

}