/*

 * Copyright 2001-2016 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the OpenSSL license (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 "eng_int.h"

/*

 * When querying a ENGINE-specific control command's 'description', this

 * string is used if the ENGINE_CMD_DEFN has cmd_desc set to NULL.

 */

static const char *int_no_description = "";

/*

 * These internal functions handle 'CMD'-related control commands when the

 * ENGINE in question has asked us to take care of it (ie. the ENGINE did not

 * set the ENGINE_FLAGS_MANUAL_CMD_CTRL flag.

 */

static int int_ctrl_cmd_is_null(const ENGINE_CMD_DEFN *defn)

{

    if ((defn->cmd_num == 0) || (defn->cmd_name == NULL))

        return 1;

    return 0;

}

static int int_ctrl_cmd_by_name(const ENGINE_CMD_DEFN *defn, const char *s)

{

    int idx = 0;

    while (!int_ctrl_cmd_is_null(defn) && (strcmp(defn->cmd_name, s) != 0)) {

        idx++;

        defn++;

    }

    if (int_ctrl_cmd_is_null(defn))

        /* The given name wasn't found */

        return -1;

    return idx;

}

static int int_ctrl_cmd_by_num(const ENGINE_CMD_DEFN *defn, unsigned int num)

{

    int idx = 0;

    /*

     * NB: It is stipulated that 'cmd_defn' lists are ordered by cmd_num. So

     * our searches don't need to take any longer than necessary.

     */

    while (!int_ctrl_cmd_is_null(defn) && (defn->cmd_num < num)) {

        idx++;

        defn++;

    }

    if (defn->cmd_num == num)

        return idx;

    /* The given cmd_num wasn't found */

    return -1;

}

static int int_ctrl_helper(ENGINE *e, int cmd, long i, void *p,

                           void (*f) (void))

{

    int idx;

    char *s = (char *)p;

    const ENGINE_CMD_DEFN *cdp;

    /* Take care of the easy one first (eg. it requires no searches) */

    if (cmd == ENGINE_CTRL_GET_FIRST_CMD_TYPE) {

        if ((e->cmd_defns == NULL) || int_ctrl_cmd_is_null(e->cmd_defns))

            return 0;

        return e->cmd_defns->cmd_num;

    }

    /* One or two commands require that "p" be a valid string buffer */

    if ((cmd == ENGINE_CTRL_GET_CMD_FROM_NAME) ||

        (cmd == ENGINE_CTRL_GET_NAME_FROM_CMD) ||

        (cmd == ENGINE_CTRL_GET_DESC_FROM_CMD)) {

        if (s == NULL) {

            ENGINEerr(ENGINE_F_INT_CTRL_HELPER, ERR_R_PASSED_NULL_PARAMETER);

            return -1;

        }

    }

    /* Now handle cmd_name -> cmd_num conversion */

    if (cmd == ENGINE_CTRL_GET_CMD_FROM_NAME) {

        if ((e->cmd_defns == NULL)

            || ((idx = int_ctrl_cmd_by_name(e->cmd_defns, s)) < 0)) {

            ENGINEerr(ENGINE_F_INT_CTRL_HELPER, ENGINE_R_INVALID_CMD_NAME);

            return -1;

        }

        return e->cmd_defns[idx].cmd_num;

    }

    /*

     * For the rest of the commands, the 'long' argument must specify a valid

     * command number - so we need to conduct a search.

     */

    if ((e->cmd_defns == NULL)

        || ((idx = int_ctrl_cmd_by_num(e->cmd_defns, (unsigned int)i)) < 0)) {

        ENGINEerr(ENGINE_F_INT_CTRL_HELPER, ENGINE_R_INVALID_CMD_NUMBER);

        return -1;

    }

    /* Now the logic splits depending on command type */

    cdp = &e->cmd_defns[idx];

    switch (cmd) {

    case ENGINE_CTRL_GET_NEXT_CMD_TYPE:

        cdp++;

        return int_ctrl_cmd_is_null(cdp) ? 0 : cdp->cmd_num;

    case ENGINE_CTRL_GET_NAME_LEN_FROM_CMD:

        return strlen(cdp->cmd_name);

    case ENGINE_CTRL_GET_NAME_FROM_CMD:

        return strlen(strcpy(s, cdp->cmd_name));

    case ENGINE_CTRL_GET_DESC_LEN_FROM_CMD:

        return strlen(cdp->cmd_desc == NULL ? int_no_description

                                            : cdp->cmd_desc);

    case ENGINE_CTRL_GET_DESC_FROM_CMD:

        return strlen(strcpy(s, cdp->cmd_desc == NULL ? int_no_description

                                                      : cdp->cmd_desc));

    case ENGINE_CTRL_GET_CMD_FLAGS:

        return cdp->cmd_flags;

    }

    /* Shouldn't really be here ... */

    ENGINEerr(ENGINE_F_INT_CTRL_HELPER, ENGINE_R_INTERNAL_LIST_ERROR);

    return -1;

}

int ENGINE_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f) (void))

{

    int ctrl_exists, ref_exists;

    if (e == NULL) {

        ENGINEerr(ENGINE_F_ENGINE_CTRL, ERR_R_PASSED_NULL_PARAMETER);

        return 0;

    }

    CRYPTO_THREAD_write_lock(global_engine_lock);

    ref_exists = ((e->struct_ref > 0) ? 1 : 0);

    CRYPTO_THREAD_unlock(global_engine_lock);

    ctrl_exists = ((e->ctrl == NULL) ? 0 : 1);

    if (!ref_exists) {

        ENGINEerr(ENGINE_F_ENGINE_CTRL, ENGINE_R_NO_REFERENCE);

        return 0;

    }

    /*

     * Intercept any "root-level" commands before trying to hand them on to

     * ctrl() handlers.

     */

    switch (cmd) {

    case ENGINE_CTRL_HAS_CTRL_FUNCTION:

        return ctrl_exists;

    case ENGINE_CTRL_GET_FIRST_CMD_TYPE:

    case ENGINE_CTRL_GET_NEXT_CMD_TYPE:

    case ENGINE_CTRL_GET_CMD_FROM_NAME:

    case ENGINE_CTRL_GET_NAME_LEN_FROM_CMD:

    case ENGINE_CTRL_GET_NAME_FROM_CMD:

    case ENGINE_CTRL_GET_DESC_LEN_FROM_CMD:

    case ENGINE_CTRL_GET_DESC_FROM_CMD:

    case ENGINE_CTRL_GET_CMD_FLAGS:

        if (ctrl_exists && !(e->flags & ENGINE_FLAGS_MANUAL_CMD_CTRL))

            return int_ctrl_helper(e, cmd, i, p, f);

        if (!ctrl_exists) {

            ENGINEerr(ENGINE_F_ENGINE_CTRL, ENGINE_R_NO_CONTROL_FUNCTION);

            /*

             * For these cmd-related functions, failure is indicated by a -1

             * return value (because 0 is used as a valid return in some

             * places).

             */

            return -1;

        }

    default:

        break;

    }

    /* Anything else requires a ctrl() handler to exist. */

    if (!ctrl_exists) {

        ENGINEerr(ENGINE_F_ENGINE_CTRL, ENGINE_R_NO_CONTROL_FUNCTION);

        return 0;

    }

    return e->ctrl(e, cmd, i, p, f);

}

int ENGINE_cmd_is_executable(ENGINE *e, int cmd)

{

    int flags;

    if ((flags =

         ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FLAGS, cmd, NULL, NULL)) < 0) {

        ENGINEerr(ENGINE_F_ENGINE_CMD_IS_EXECUTABLE,

                  ENGINE_R_INVALID_CMD_NUMBER);

        return 0;

    }

    if (!(flags & ENGINE_CMD_FLAG_NO_INPUT) &&

        !(flags & ENGINE_CMD_FLAG_NUMERIC) &&

        !(flags & ENGINE_CMD_FLAG_STRING))

        return 0;

    return 1;

}

int ENGINE_ctrl_cmd(ENGINE *e, const char *cmd_name,

                    long i, void *p, void (*f) (void), int cmd_optional)

{

    int num;

    if (e == NULL || cmd_name == NULL) {

        ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD, ERR_R_PASSED_NULL_PARAMETER);

        return 0;

    }

    if (e->ctrl == NULL

        || (num = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FROM_NAME,

                              0, (void *)cmd_name, NULL)) <= 0) {

        /*

         * If the command didn't *have* to be supported, we fake success.

         * This allows certain settings to be specified for multiple ENGINEs

         * and only require a change of ENGINE id (without having to

         * selectively apply settings). Eg. changing from a hardware device

         * back to the regular software ENGINE without editing the config

         * file, etc.

         */

        if (cmd_optional) {

            ERR_clear_error();

            return 1;

        }

        ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD, ENGINE_R_INVALID_CMD_NAME);

        return 0;

    }

    /*

     * Force the result of the control command to 0 or 1, for the reasons

     * mentioned before.

     */

    if (ENGINE_ctrl(e, num, i, p, f) > 0)

        return 1;

    return 0;

}

int ENGINE_ctrl_cmd_string(ENGINE *e, const char *cmd_name, const char *arg,

                           int cmd_optional)

{

    int num, flags;

    long l;

    char *ptr;

    if (e == NULL || cmd_name == NULL) {

        ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING, ERR_R_PASSED_NULL_PARAMETER);

        return 0;

    }

    if (e->ctrl == NULL

        || (num = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FROM_NAME,

                              0, (void *)cmd_name, NULL)) <= 0) {

        /*

         * If the command didn't *have* to be supported, we fake success.

         * This allows certain settings to be specified for multiple ENGINEs

         * and only require a change of ENGINE id (without having to

         * selectively apply settings). Eg. changing from a hardware device

         * back to the regular software ENGINE without editing the config

         * file, etc.

         */

        if (cmd_optional) {

            ERR_clear_error();

            return 1;

        }

        ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING, ENGINE_R_INVALID_CMD_NAME);

        return 0;

    }

    if (!ENGINE_cmd_is_executable(e, num)) {

        ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,

                  ENGINE_R_CMD_NOT_EXECUTABLE);

        return 0;

    }

    flags = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FLAGS, num, NULL, NULL);

    if (flags < 0) {

        /*

         * Shouldn't happen, given that ENGINE_cmd_is_executable() returned

         * success.

         */

        ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,

                  ENGINE_R_INTERNAL_LIST_ERROR);

        return 0;

    }

    /*

     * If the command takes no input, there must be no input. And vice versa.

     */

    if (flags & ENGINE_CMD_FLAG_NO_INPUT) {

        if (arg != NULL) {

            ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,

                      ENGINE_R_COMMAND_TAKES_NO_INPUT);

            return 0;

        }

        /*

         * We deliberately force the result of ENGINE_ctrl() to 0 or 1 rather

         * than returning it as "return data". This is to ensure usage of

         * these commands is consistent across applications and that certain

         * applications don't understand it one way, and others another.

         */

        if (ENGINE_ctrl(e, num, 0, (void *)arg, NULL) > 0)

            return 1;

        return 0;

    }

    /* So, we require input */

    if (arg == NULL) {

        ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,

                  ENGINE_R_COMMAND_TAKES_INPUT);

        return 0;

    }

    /* If it takes string input, that's easy */

    if (flags & ENGINE_CMD_FLAG_STRING) {

        /* Same explanation as above */

        if (ENGINE_ctrl(e, num, 0, (void *)arg, NULL) > 0)

            return 1;

        return 0;

    }

    /*

     * If it doesn't take numeric either, then it is unsupported for use in a

     * config-setting situation, which is what this function is for. This

     * should never happen though, because ENGINE_cmd_is_executable() was

     * used.

     */

    if (!(flags & ENGINE_CMD_FLAG_NUMERIC)) {

        ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,

                  ENGINE_R_INTERNAL_LIST_ERROR);

        return 0;

    }

    l = strtol(arg, &ptr, 10);

    if ((arg == ptr) || (*ptr != '\0')) {

        ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,

                  ENGINE_R_ARGUMENT_IS_NOT_A_NUMBER);

        return 0;

    }

    /*

     * Force the result of the control command to 0 or 1, for the reasons

     * mentioned before.

     */

    if (ENGINE_ctrl(e, num, l, NULL, NULL) > 0)

        return 1;

    return 0;

}