[openssl-project] To use or not use the iconv API, and to use or not use other libraries

[Bernd Edlinger]

On 06/11/18 17:40, Richard Levitte wrote:
> In message <8EE45344-9BFC-44F9-9DB2-C384F7645CD6 at akamai.com> on Mon, 11 Jun 2018 15:25:23 +0000, "Salz, Rich" <rsalz at akamai.com> said:
> 
> rsalz> >    *must* do when getting '-pass8bit' is to do a naïve UTF-8 encode of
> rsalz>     the input pass phrase string.  PKCS12_generate_mac() will then decode
> rsalz>
> rsalz> I disagree.
> rsalz>
> rsalz> There are two reasons why users enter "illegal" passwords now,
> rsalz> and by now requiring them to make it explicit we can (a) check
> rsalz> only for ASCII on current inputs; (b) make them thing about
> rsalz> what they're doing and require them to specify; (c) set the
> rsalz> expectation that something will change in the future.
> 
> [btw, PKCS12_gen_mac(), not PKCS12_generate_mac()]
> 
> So wait, if the user enters this:
> 
>      openssl pkcs12 -export -in foo.pem -out foo.p12 \
>          -pass8bit -password pass:`echo 72c3a46b61 | xxd -r -p`
> 
> ...  then it seems "natural" that the user would expect the resulting
> BMPString to become this set of bytes, right?
> 
>      0x00, 0x72, 0x00, 0xc3, 0x00, 0xa4, 0x00, 0x6b, 0x00, 0x61, 0x00, 0x00
> 
> However, what's going to happen is that PKCS12_gen_mac() will generate
> this for a BMPString:
> 
>      0x00, 0x72, 0x00, 0xe4, 0x00, 0x6b, 0x00, 0x61, 0x00, 0x00
> 
> Why?  Because the input pass phrase can be interpreted as a UTF-8
> encoded string, and PKCS12_gen_mac() will decode it thusly.
> 
>  From a user interface point of view, I would fine such behavior very
> surprising, and not at all what I'd expect for a flag named '-pass8bit'
> 

I think there are many ways for the user to shoot into his own knee with
entering unicode glyphs accidentally, with are even invisible when
printed to the console, just think of the EM DASH U+2014: "—"
Or unicode non break space U+00A0 which looks like an ordinary space but
is something different

As a user, I would not be happy if one of these slipped into a password,
that's certainly sure.

So in my opinion when entering new passwords it should be restricted to
7bit ASCII printable characters, except if advised otherwise by an
option like -pass8bit.


Bernd.