Decrypt and mount an eCryptFS encrypted directory using an external C++ script in Linux

Question

I want to decrypt and mount the default eCryptfs private directory by executing the "ecryptfs-mount-private" terminal command in C++ and providing the passphrase/password from the same C++ script.

I have tried forking then exec the shell (/bin/sh) and opening pipes for I/O with sh but when I try to write through the pipe I get the following error:

stty: standard input: Inappropriate ioctl for device

I guess this is because ecryptfs-mount-private only accepts input for a passphrase from the keyboard.

How can I achieve this type of decrypt and mount mechanism? Possible ways of doing this or any workarounds will be helpful.

PS. Security concern of storing the passphrase in the C++ code is not a problem in my scenario.

Thanks!

Answer 1

ecryptfs-mount-private是一个/bin/sh shell脚本（相对较短，只有65行，没有注释），因此您可以尝试将其中的一些“转换”为C ++和/或将其余的shell命令行一次运行。与system()时间。

Answer 2

ecrypt-mountfs-private expects to be attached to a terminal. One solution is to use forkpty (2) instead of fork , which will ensure the child process has access to a pty (pseudo-tty). You can then write to and read from the master file descriptor to provide input resp. read output from the child process.