finsh password 问题

发布于 2022-03-31 22:41:14 浏览：1227 订阅该版

```c
* set a new password for finsh
 *
 * @param password new password
 *
 * @return result, RT_EOK on OK, -RT_ERROR on the new password length is less than
 *  FINSH_PASSWORD_MIN or greater than FINSH_PASSWORD_MAX
 */
rt_err_t finsh_set_password(const char *password) {
    rt_ubase_t level;
    rt_size_t pw_len = rt_strlen(password);

if (pw_len < FINSH_PASSWORD_MIN || pw_len > FINSH_PASSWORD_MAX)
        return -RT_ERROR;

level = rt_hw_interrupt_disable();
    rt_strncpy(shell->password, password, FINSH_PASSWORD_MAX);
    rt_hw_interrupt_enable(level);

return RT_EOK;
}

/**
 * get the finsh password
 *
 * @return password
 */
const char *finsh_get_password(void)
{
    return shell->password;
}

static void finsh_wait_auth(void)
{
    char ch;
    rt_bool_t input_finish = RT_FALSE;
    char password[FINSH_PASSWORD_MAX] = { 0 };
    rt_size_t cur_pos = 0;
    /* password not set */
    if (rt_strlen(finsh_get_password()) == 0) return;

while (1)
    {
        rt_kprintf("Password for login: ");
        while (!input_finish)
        {
            while (1)
            {
                /* read one character from device */
                ch = finsh_getchar();

if (ch >= ' ' && ch <= '~' && cur_pos < FINSH_PASSWORD_MAX)
                {
                    /* change the printable characters to '*' */
                    rt_kprintf("*");
                    password[cur_pos++] = ch;
                }
                else if (ch == '\b' && cur_pos > 0)
                {
                    /* backspace */
                    password[cur_pos] = '\0';
                    cur_pos--;
                    rt_kprintf("\b \b");
                }
                else if (ch == '\r' || ch == '\n')
                {
                    rt_kprintf("\n");
                    input_finish = RT_TRUE;
                    break;
                }
            }
        }
        if (!rt_strncmp(shell->password, password, FINSH_PASSWORD_MAX)) return;
        else
        {
            /* authentication failed, delay 2S for retry */
            rt_thread_delay(2 * RT_TICK_PER_SECOND);
            rt_kprintf("Sorry, try again.\n");
            cur_pos = 0;
            input_finish = RT_FALSE;
            rt_memset(password, '\0', FINSH_PASSWORD_MAX);
        }
    }
}
```
这段代码，在那里引用。

crystal266 2022-04-01

嵌入式

设置密码和密码验证的代码是在 finsh 线程的执行函数里面调用的，finsh 线程的创建代码如下：
```c
/* 代码位于 rt-thread/components/finsh/shell.c 文件中 */
int finsh_system_init(void)
{
    ... ... // 省略

#ifdef RT_USING_HEAP
    /* create or set shell structure */
    shell = (struct finsh_shell *)rt_calloc(1, sizeof(struct finsh_shell));
    if (shell == RT_NULL)
    {
        rt_kprintf("no memory for shell\n");
        return -1;
    }
    /* 创建 finsh 线程 */
    tid = rt_thread_create(FINSH_THREAD_NAME,
                           finsh_thread_entry, RT_NULL,
                           FINSH_THREAD_STACK_SIZE, FINSH_THREAD_PRIORITY, 10);
#else
    shell = &_shell;
    tid = &finsh_thread;
    result = rt_thread_init(&finsh_thread,
                            FINSH_THREAD_NAME,
                            finsh_thread_entry, RT_NULL,
                            &finsh_thread_stack[0], sizeof(finsh_thread_stack),
                            FINSH_THREAD_PRIORITY, 10);
#endif /* RT_USING_HEAP */

rt_sem_init(&(shell->rx_sem), "shrx", 0, 0);
    finsh_set_prompt_mode(1);

if (tid != NULL && result == RT_EOK)
        rt_thread_startup(tid); /* 启动 finsh 线程 */
    return 0;
}
INIT_APP_EXPORT(finsh_system_init);
```

启动 finsh 线程后，该线程的处理执行函数如下：从代码可以看出线程执行函数上来一开始就执行了密码设置的工作，实质是把定义的密码拷贝到了 struct finsh_shell *shell; 这个全局的结构体指针变量里面。然后在 finsh_wait_auth() 函数里面等待用户输入密码，然后和 shell->password 存放的密码进行比较，比对一致接着往下执等待用户输入命令，比对不一致提示密码错误等待用户下一次输入。
```c
/* 代码位于 rt-thread/components/finsh/shell.c 文件中 */
void finsh_thread_entry(void *parameter)
{
    ... ... // 省略

#ifdef FINSH_USING_AUTH
    /* set the default password when the password isn't setting */
    if (rt_strlen(finsh_get_password()) == 0)
    {
        if (finsh_set_password(FINSH_DEFAULT_PASSWORD) != RT_EOK)   // 设置密码
        {
            rt_kprintf("Finsh password set failed.\n");
        }
    }
    /* waiting authenticate success */
    finsh_wait_auth();  // 密码验证，验证失败不往下运行一直等到验证成功
#endif

rt_kprintf(FINSH_PROMPT);

while (1)
    {
        ch = (int)finsh_getchar();  // 阻塞读取输入的字符
        if (ch < 0)
        {
            continue;
        }

... ...  // 省略

/* handle end of line, break */
        if (ch == '\r' || ch == '\n')
        {
#ifdef FINSH_USING_HISTORY
            shell_push_history(shell);
#endif
            if (shell->echo_mode)
                rt_kprintf("\n");
            msh_exec(shell->line, shell->line_position);    // 查找输入的命令并执行

rt_kprintf(FINSH_PROMPT);
            memset(shell->line, 0, sizeof(shell->line));
            shell->line_curpos = shell->line_position = 0;
            continue;
        }
        ... ...  // 省略
    } /* end of device read */
}
```