[Libguestfs] [PATCH 1/1] hivexml: Base64-encode non-printable data

[Richard W.M. Jones]

On Sat, Sep 17, 2011 at 09:53:31AM -0700, Alex Nelson wrote:
> Basically, if any of the characters passed to a hivexml.c function aren't isprint()-able, they're base64-encoded.
> 
> The characters passed rely on the iconv library.  Whatever comes out of the processing of iconv() in "UTF-8 or UTF-16" mode is what's passed to hivexml.  I checked all the UTF-processing points and have extensive notes in the postscript, but essentially:
> * Key and value names aren't run through iconv
> * Value string data and the hive header name are
> * The patch below runs a stricter sanitization than iconv, also running everything through isprint.

I agree with Simson that this gets tricky.

You might consider changing hivexml so it avoids APIs like
hivex_value_string, hivex_value_multiple_strings, etc. (or the
corresponding visitor callbacks).  It should probably only use
hivex_value_value and do all character conversion itself.

There's also a big difference between what Windows is documented as
doing and what it is doing in reality ...

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
libguestfs lets you edit virtual machines.  Supports shell scripting,
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