+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_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;
+ }
+ 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. */
+ 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))
+ 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))
+ 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))
+ return 1;
+ return 0;
+ }
+