CreateFile("CONIN $" ..)做什么? [英] What does CreateFile("CONIN$" ..) do?
问题描述
我正在破解 plink 的源代码使其与统一兼容.
I was hacking away the source code for plink to make it compatible with unison.
如果您不知道，统一是一种文件同步工具，它将运行"ssh"命令以连接到远程服务器，但是Windows没有ssh.exe；有一个plink，它非常接近但不够紧密(它的行为不像统一预期的那样)，因此人们通常在它周围包装，
If you don't know, unison is a file synchronization tool, it runs an "ssh" command to connect to a remote server, but there's no ssh.exe for windows; there's plink, which is very close but not close enough (it doesn't behave like unison expects it to), so people usually make wrappers around it, like this one.
问题之一是，统一要求密码提示打印到stderr(但是plink将密码提示打印到stdout，并导致统一混淆)，所以我认为，应该足够简单，通过plink的代码来破解我的代码并将其打印到stdout的提示.所以我闯了进去，然后做到了.
one of the problems is that unison expects the password prompt to print to stderr (but plink prints it to stdout, and causes unison to be confused), so I thought, well, should be simple enough, hack my thru plink's code and make it print the prompt to stdout. so I hacked my way through and did that.
下一个问题:我无法回应提示！！不管我输入什么，都没有效果.
Next problem: I can't respond to the prompt!! no matter what I type, it has no effect.
获取输入的代码大致如下:
the code for getting input is roughly like this:
hin = GetStdHandle(STD_INPUT_HANDLE);
....
r = ReadFile(hin, .....);
我不确定为什么要这样做，但是我不是为Windows设计命令行工具的专家，所以我知道些什么！但是我认为设置输入句柄时缺少某些东西.
I'm not sure why it's done this way, but I'm not an expert in designing command line tools for windows, so what do I know! But I figure something is missing in setting up the input handle.
我查看了包装工具上方的源代码，我看到了:
hconin=CreateFile("CONIN$",GENERIC_READ|GENERIC_WRITE,FILE_SHARE_READ,0,OPEN_EXISTING,0,0)
I looked at the source code for the above wrapper tool and I see this:
hconin=CreateFile("CONIN$",GENERIC_READ|GENERIC_WRITE,FILE_SHARE_READ,0,OPEN_EXISTING,0,0)
我尝试了(只是为了尝试)
and I try it (just for the heck of it)
hin=CreateFile("CONIN$",GENERIC_READ|GENERIC_WRITE,FILE_SHARE_READ,0,OPEN_EXISTING,0,0);
....
r = ReadFile( hin ...... )
并且令人惊讶的是它起作用了！我现在可以回应提示了！
and surprisingly it works! I can now respond to the prompt!
这是为什么?什么是"CONIN $"?为何与STD_INPUT_HANDLE不同?
Why is this? what is "CONIN$"? and why is it different from the STD_INPUT_HANDLE?
我可以猜测" FILE_SHARE_READ和OPEN_EXISTING在其中起作用(因为ssh从另一个进程中运行)，但是我想了解这里发生的事情，并确保该代码没有任何有害的副作用，安全漏洞或类似的可怕内容！
I can sort of "guess" that FILE_SHARE_READ and OPEN_EXISTING are playing a role in this (since ssh is being run from within another process), but I want to understand what's going on here, and make sure that this code doesn't have some unwanted side effects or security holes or something scary like that!
推荐答案
CONIN$是控制台输入设备.通常，stdin是对此的打开文件句柄，但是如果stdin由于某种原因而被重定向，则使用CONIN$将允许您即使重定向也可以访问控制台. 参考.
CONIN$ is the console input device. Normally, stdin is an open file handle to this, but if stdin is redirected for some reason, then using CONIN$ will allow you to get access to the console despite the redirection. Reference.
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