Re: [Qemu-devel] Re: [PATCH] qemu-img: set encrypted disk image password

[Laurent Vivier]

Le 30 juil. 08 à 22:18, address@hidden a écrit :

> > Qemu-img doesn't need a password when it creates the disk image  
> > because there is nothing to encrypt in an empty image and the  
> > password is never stored in it.
>
> Okay... this might be better documented.
>
> I somewhat expected that most of the meta data for an encrypted disk  
> would also be encrypted, maybe with the execption of a simple  
> signature at the start.

Meta-data are not encrypted, only data.

Meta-data cannot give any information about data, allowing someone to  
crack the key. So encrypting data is enough.

For instance, when you encrypt a file on ext3, you don't encrypt the  
filesystem metadata (like inode and block pointers). Meta-data of  
qcow2 are like meta-data of ext3.

Regards,
Laurent
----------------------- Laurent Vivier ----------------------
"The best way to predict the future is to invent it."
- Alan Kay