crypto/provider_conf.c

/*
 * 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 "internal/provider.h"
#include "internal/cryptlib.h"

DEFINE_STACK_OF(OSSL_PROVIDER)

/* PROVIDER config module */

typedef struct {
    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;

    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");
    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,
                                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, 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);
        ok = ossl_provider_add_parameter(prov, name, value);
    }

    return ok;
}

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;
    const char *path = NULL;
    long activate = 0;
    int ok = 0;
    PROVIDER_CONF_GLOBAL *pcgbl
        = ossl_lib_ctx_get_data(libctx, OSSL_LIB_CTX_PROVIDER_CONF_INDEX,
                                &provider_conf_ossl_ctx_method);

    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;
    }

    prov = ossl_provider_find(libctx, name, 1);
    if (prov == NULL)
        prov = ossl_provider_new(libctx, name, NULL, 1);
    if (prov == NULL) {
        if (soft)
            ERR_clear_error();
        return 0;
    }

    if (path != NULL)
        ossl_provider_set_module_path(prov, path);

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

    if (ok && activate) {
        if (!ossl_provider_activate(prov, 0, 1)) {
            ok = 0;
        } else {
            if (pcgbl->activated_providers == NULL)
                pcgbl->activated_providers = sk_OSSL_PROVIDER_new_null();
            sk_OSSL_PROVIDER_push(pcgbl->activated_providers, prov);
            ok = 1;
        }
    }

    if (!(activate && ok))
        ossl_provider_free(prov);

    return ok;
}

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);
}