Re: What we were using public key authentication for

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On 30 March 2016 at 18:23, Dave Longley <[email protected]> wrote:

> On 03/30/2016 12:09 PM, Graham Leggett wrote:
>
>> On 30 Mar 2016, at 6:00 PM, Dave Longley <[email protected]>
>> wrote:
>>
>> As a quick, temporary replacement for keygen, you should be able to
>>> use forge (or forge + WebCrypto) to generate a keypair and wrap it
>>> in a PKCS#12 container that can be downloaded via a link that, when
>>> clicked, may bring up an import dialog in the user's browser. They
>>> may have to save the file first before importing, I'm not sure.
>>>
>>> forge: https://github.com/digitalbazaar/forge
>>>
>>> There's some somewhat messy X.509 cert creation and PKCS#12 code
>>> that could be adapted from this issue:
>>>
>>> https://github.com/digitalbazaar/forge/issues/211#issuecomment-85447100
>>>
>>
>>
>>>
>>> Does this guarantee that the key was a) generated on the client side
>>  only (and not anywhere else and injected into the conversation), and
>>  b) that this key cannot be subsequently exported and uploaded to
>> some third party location under the control of third party server
>> code?
>>
>
> The short answer is "No", as there is presently no direct replacement
> for keygen. I was just offering a quick temporary fix. If it's true that
> keygen has now been removed (not just deprecated), I would expect that
> systems that relied upon it need *something* that they can throw
> together quickly in the interim (meaning, until some other replacement
> can solve their problem long term).
>

As I understand it keygen is NOT removed in firefox (or most versions of
other browsers).  What I heard (perhaps someone will confirm) is that
Mozilla will take the TAG advice, to remove existing functionality that is
in use, only after it has been adequately replaced.


>
> The longer answer is that the key pair is, in fact, generated
> client-side, however, using code that is controlled by the website. That
> site must be trusted not to do anything nefarious with the private key
> while the site has access to it. Once the key pair has been exported to
> a PKCS#12 and imported into the user's local key store, and the site has
> been navigated away from, the website has no access to the private key,
> should, for example, the site become compromised in the future.
>
>
>
> --
> Dave Longley
> CTO
> Digital Bazaar, Inc.
> http://digitalbazaar.com
>

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<div dir=3D"ltr"><br><div class=3D"gmail_extra"><br><div class=3D"gmail_quo=
te">On 30 March 2016 at 18:23, Dave Longley <span dir=3D"ltr">&lt;<a href=
=3D"mailto:[email protected]" target=3D"_blank">dlongley@digitalba=
zaar.com</a>&gt;</span> wrote:<br><blockquote class=3D"gmail_quote" style=
=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><span cl=
ass=3D"">On 03/30/2016 12:09 PM, Graham Leggett wrote:<br>
<blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1p=
x #ccc solid;padding-left:1ex">
On 30 Mar 2016, at 6:00 PM, Dave Longley &lt;<a href=3D"mailto:dlongley@dig=
italbazaar.com" target=3D"_blank">[email protected]</a>&gt;<br>
wrote:<br>
<br>
<blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1p=
x #ccc solid;padding-left:1ex">
As a quick, temporary replacement for keygen, you should be able to<br>
use forge (or forge + WebCrypto) to generate a keypair and wrap it<br>
in a PKCS#12 container that can be downloaded via a link that, when<br>
clicked, may bring up an import dialog in the user&#39;s browser. They<br>
may have to save the file first before importing, I&#39;m not sure.<br>
<br>
forge: <a href=3D"https://github.com/digitalbazaar/forge" rel=3D"noreferrer=
" target=3D"_blank">https://github.com/digitalbazaar/forge</a><br>
<br>
There&#39;s some somewhat messy X.509 cert creation and PKCS#12 code<br>
that could be adapted from this issue:<br>
<br>
<a href=3D"https://github.com/digitalbazaar/forge/issues/211#issuecomment-8=
5447100" rel=3D"noreferrer" target=3D"_blank">https://github.com/digitalbaz=
aar/forge/issues/211#issuecomment-85447100</a><br>
</blockquote>
<br>
<blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1p=
x #ccc solid;padding-left:1ex">
<br>
<br>
</blockquote>
Does this guarantee that the key was a) generated on the client side<br>
=C2=A0only (and not anywhere else and injected into the conversation), and<=
br>
=C2=A0b) that this key cannot be subsequently exported and uploaded to<br>
some third party location under the control of third party server<br>
code?<br>
</blockquote>
<br></span>
The short answer is &quot;No&quot;, as there is presently no direct replace=
ment<br>
for keygen. I was just offering a quick temporary fix. If it&#39;s true tha=
t<br>
keygen has now been removed (not just deprecated), I would expect that<br>
systems that relied upon it need *something* that they can throw<br>
together quickly in the interim (meaning, until some other replacement<br>
can solve their problem long term).<br></blockquote><div><br></div><div>As =
I understand it keygen is NOT removed in firefox (or most versions of other=
 browsers).=C2=A0 What I heard (perhaps someone will confirm) is that Mozil=
la will take the TAG advice, to remove existing functionality that is in us=
e, only after it has been adequately replaced.<br></div><div>=C2=A0</div><b=
lockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px =
#ccc solid;padding-left:1ex">
<br>
The longer answer is that the key pair is, in fact, generated<br>
client-side, however, using code that is controlled by the website. That<br=
>
site must be trusted not to do anything nefarious with the private key<br>
while the site has access to it. Once the key pair has been exported to<br>
a PKCS#12 and imported into the user&#39;s local key store, and the site ha=
s<br>
been navigated away from, the website has no access to the private key,<br>
should, for example, the site become compromised in the future.<div class=
=3D"HOEnZb"><div class=3D"h5"><br>
<br>
<br>
-- <br>
Dave Longley<br>
CTO<br>
Digital Bazaar, Inc.<br>
<a href=3D"http://digitalbazaar.com" rel=3D"noreferrer" target=3D"_blank">h=
ttp://digitalbazaar.com</a><br>
</div></div></blockquote></div><br></div></div>

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