On Sat, Mar 26, 2016 at 9:38 PM, Stanislav Malyshev <smalys...@gmail.com>
wrote:

> Hi!
>
> > PHP already offers bin2hex()/hex2bin() and
> base64_encode()/base64_decode().
> > This covers part, but not all, of RFC 4648.
> >
> > I'd like to extend the coverage to include, at minimum, Base32.
>
> What's the use case for it? Is anybody using base32 now?
>
> > I'd also like to make these functions to be written to resist
> cache-timing
> > attacks (i.e. when used to encode/decode encryption keys for long-term
> > storage). Userland PoC:
> https://github.com/paragonie/constant_time_encoding
> > These modifications can either be made in-place (at a negligble cost on
> the
> > scale of nanoseconds) or they can be an alternative implementation. i.e.
>
> What modification needs to be done for existing one? Since encoding
> functions (unlike comparison ones) have to process every bit anyway, so
> what are timing differences for e.g. base64? Is there any existing
> research for this?
>
> >
> >     * bin2hex_ts()
> >     * base64_encode_ts()
> >     * base32_encode_ts()
>
> If you have encode functions, you should have decode too? Otherwise,
> you'd have the same issue every time the key is read.
>
> --
> Stas Malyshev
> smalys...@gmail.com
>

​Google Authenticator and Tor Hidden Services both use base32. I was also
going to cover the decoding functions in the RFC.​

Scott Arciszewski
Chief Development Officer
Paragon Initiative Enterprises <https://paragonie.com/>​

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