/* $OpenBSD: eng_ctrl.c,v 1.11 2017/01/29 17:49:23 beck Exp $ */
/* ====================================================================
 * Copyright (c) 1999-2001 The OpenSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    licensing@OpenSSL.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */

#include <string.h>

#include <openssl/err.h>

#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;
        int ret;
        char *s = (char *)p;

        /* 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) {
                        ENGINEerror(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)) {
                        ENGINEerror(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
         * valie 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)) {
                ENGINEerror(ENGINE_R_INVALID_CMD_NUMBER);
                return -1;
        }
        /* Now the logic splits depending on command type */
        switch (cmd) {
        case ENGINE_CTRL_GET_NEXT_CMD_TYPE:
                idx++;
                if (int_ctrl_cmd_is_null(e->cmd_defns + idx))
                        /* end-of-list */
                        return 0;
                else
                        return e->cmd_defns[idx].cmd_num;
        case ENGINE_CTRL_GET_NAME_LEN_FROM_CMD:
                return strlen(e->cmd_defns[idx].cmd_name);
        case ENGINE_CTRL_GET_NAME_FROM_CMD:
                ret = snprintf(s, strlen(e->cmd_defns[idx].cmd_name) + 1,
                    "%s", e->cmd_defns[idx].cmd_name);
                if (ret >= (strlen(e->cmd_defns[idx].cmd_name) + 1))
                        ret = -1;
                return ret;
        case ENGINE_CTRL_GET_DESC_LEN_FROM_CMD:
                if (e->cmd_defns[idx].cmd_desc)
                        return strlen(e->cmd_defns[idx].cmd_desc);
                return strlen(int_no_description);
        case ENGINE_CTRL_GET_DESC_FROM_CMD:
                if (e->cmd_defns[idx].cmd_desc) {
                        ret = snprintf(s,
                            strlen(e->cmd_defns[idx].cmd_desc) + 1,
                            "%s", e->cmd_defns[idx].cmd_desc);
                        if (ret >= strlen(e->cmd_defns[idx].cmd_desc) + 1)
                                ret = -1;
                        return ret;
                }
                ret = snprintf(s, strlen(int_no_description) + 1, "%s",
                    int_no_description);
                if (ret >= strlen(int_no_description) + 1)
                        ret = -1;
                return ret;
        case ENGINE_CTRL_GET_CMD_FLAGS:
                return e->cmd_defns[idx].cmd_flags;
        }

        /* Shouldn't really be here ... */
        ENGINEerror(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) {
                ENGINEerror(ERR_R_PASSED_NULL_PARAMETER);
                return 0;
        }
        CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
        ref_exists = ((e->struct_ref > 0) ? 1 : 0);
        CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
        ctrl_exists = ((e->ctrl == NULL) ? 0 : 1);
        if (!ref_exists) {
                ENGINEerror(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) {
                        ENGINEerror(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) {
                ENGINEerror(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) {
                ENGINEerror(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)) {
                ENGINEerror(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;
                }
                ENGINEerror(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)) {
                ENGINEerror(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;
                }
                ENGINEerror(ENGINE_R_INVALID_CMD_NAME);
                return 0;
        }
        if (!ENGINE_cmd_is_executable(e, num)) {
                ENGINEerror(ENGINE_R_CMD_NOT_EXECUTABLE);
                return 0;
        }
        if ((flags = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FLAGS, num,
            NULL, NULL)) < 0) {
                /* Shouldn't happen, given that ENGINE_cmd_is_executable()
                 * returned success. */
                ENGINEerror(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) {
                        ENGINEerror(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) {
                ENGINEerror(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)) {
                ENGINEerror(ENGINE_R_INTERNAL_LIST_ERROR);
                return 0;
        }
        l = strtol(arg, &ptr, 10);
        if ((arg == ptr) || (*ptr != '\0')) {
                ENGINEerror(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;
}