OASIS Mailing List ArchivesView the OASIS mailing list archive below
or browse/search using MarkMail.

 


Help: OASIS Mailing Lists Help | MarkMail Help

xri message

[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]


Subject: Re: [xri] SimpleSign Implementation


On Wed, Dec 24, 2008 at 10:29 PM, Barnhill, William [USA]
<barnhill_william@bah.com> wrote:
>
> Good to know, thanks. I was going by Henson's email (from Dec 2007) and he
> does mention the backport into 0.9.8f in that, but he says it's optional and
> not enabled by default. I don't know if that's still the case and sent an
> email to openssl-dev to find out.  If it's still not enabled by default then
> wouldn't that require a recompile of OpenSSL (and possibly other linked
> libraries) to get the SNI support? Not a big issue for many, but a
> show-stopper for some.

It is disabled by default, which is a good point. I think we should
change that around.

>
> Thanks,
> =Bill.Barnhill
>
>
> -----Original Message-----
> From: Ben Laurie [mailto:benl@google.com]
> Sent: Wed 12/24/2008 4:32 PM
> To: Barnhill, William [USA]
> Cc: Nat Sakimura; Joseph Anthony Pasquale Holsten; XRI TC
> Subject: Re: [xri] SimpleSign Implementation
>
> On Wed, Dec 24, 2008 at 4:40 PM, Barnhill, William [USA]
> <barnhill_william@bah.com> wrote:
>>
>> SNI extension would be nice to use in spec, but I'm -1 because of the lack
>> of support in OpenSSL. Many languages, including Erlang, base their TLS
>> libraries on OpenSSL and SNI support is not baked in yet (possibly in
>> 0.9.9).  If you made an SNI suage profile a separate optional extension
>> document, that could work as the devs using an OpenSSL with no SNI support
>> would not be impacted.
>>
>> "Originally no released version of OpenSSL supported SNI it was an
>> experimental addition to the HEAD which will become 0.9.9-dev."
>>  - Dr Stephen N. Henson., Core OpenSSL dev, on the mod_ssl list
>>    http://www.mail-archive.com/dev@httpd.apache.org/msg39034.html
>
> SNI went into OpenSSL 0.9.8f, over a year ago, I believe.
>
>> I found XML DSig complicated as well, but it seems well modularized so
>> that
>> you could create a SimpleSign XML DSig profile that removed a lot of the
>> complexity.
>>
>> As for lack of implementations that seems to be changing, with
>> implementations in Java, C#, Visual Basic, and the more popular scripting
>> languages. See the following links for more info:
>> ..
>>
>> http://identitymeme.org/archives/2006/12/20/xmldsig-implementations-for-scripting-languages/
>> ..  http://www.example-code.com/vb/sig.asp
>> ..  http://www.cpan.org/modules/by-module/Net/zxid-0.19.readme
>> ..
>>
>> http://www.koders.com/csharp/fid9399EBD1942CEF08BBA770E41302AB42B452B9B4.aspx
>>
>> YMMV on the above, but they do exist.
>>
>> Also, the SAML TC takes a different approach that presents another option:
>> "This specification defines a SAML HTTP protocol binding, specifically
>> using
>> the HTTP POST method, and
>> which specifically does not use XML Digital Signature [XMLSig] for SAML
>> message data origination
>> authentication. Rather, a "sign the BLOB" technique is employed wherein a
>> conveyed SAML message,
>> along with any content (e.g. SAML assertion(s)), is treated as a simple
>> octet string if it is signed."
>>  - SAMLv2.0 HTTP POST "SimpleSign" Binding CS01
>>
>>
>> http://www.oasis-open.org/committees/download.php/28046/sstc-saml-binding-simplesign-cs-01.pdf
>>
>> =Bill.Barnhill
>>
>> -----Original Message-----
>> From: Ben Laurie [mailto:benl@google.com]
>> Sent: Wed 12/24/2008 6:54 AM
>> To: Nat Sakimura
>> Cc: Joseph Anthony Pasquale Holsten; XRI TC
>> Subject: Re: [xri] SimpleSign Implementation
>>
>> On Wed, Dec 24, 2008 at 3:16 AM, Nat Sakimura <n-sakimura@nri.co.jp>
>> wrote:
>>>
>>>
>>> Ben Laurie wrote:
>>>>
>>>> On Mon, Dec 22, 2008 at 1:29 AM, Nat Sakimura <n-sakimura@nri.co.jp>
>>>> wrote:
>>>>
>>>>>
>>>>> Hi.
>>>>>
>>>>> No, it si not silly. It is a good question to ask.
>>>>>
>>>>> My answer would be:
>>>>>
>>>>> a) TLS is only a security for the pipes. It does not protect the
>>>>> message
>>>>> per
>>>>> se.
>>>>>  With a signed document, you can verify the authenticity and validity
>>>>> of
>>>>> a
>>>>> cache / detached document.
>>>>> b) TLS requires a dedicated IP address. Sites like Google providing
>>>>> services
>>>>> to
>>>>>  the companies in the companies' domain do not have enough IP address
>>>>> to
>>>>> server TLS.
>>>>>  This is another reason.
>>>>>
>>>>
>>>> This is not actually true anymore - you can use the SNI extension to
>>>> share an IP address. Because legacy browsers don't support it, it
>>>> isn't so great for websites, but for a specialist application like
>>>> retrieving XRD it would work just fine.
>>>>
>>>
>>> Are they implemented widely in common scripting language libraries?
>>
>> Yes.
>>
>>> Are they implemented widely in the current http servers?
>>
>> Yes.
>>
>>>>
>>>>
>>>>>
>>>>> c) There are not enough XMLDSIG implementations yet, and it is complex
>>>>> to
>>>>> implement yourself.
>>>>>  This is becoming a hinderance to the adoption.
>>>>>
>>>>> a) and b) calls for a message based protection. This calls for
>>>>> something
>>>>> like XML Dsig.
>>>>> c) Calls for something simpler than XML Dsig.
>>>>>
>>>>
>>>> Or more implementations.
>>>>
>>>
>>> Yes. And we are not seeing these yet, unfortunately.
>>> (BTW, that's another initiative I am willing to run when I get more
>>> bandwidth.)
>>>>
>>>>
>>>>>
>>>>> Therefore, we have SimpleSign.
>>>>>
>>>>> Regards,
>>>>>
>>>>> =nat
>>>>>
>>>>> Joseph Anthony Pasquale Holsten wrote:
>>>>>
>>>>>>
>>>>>> I'm trying to wrap my head around the security implications of
>>>>>> SimpleSign, and I'm wondering where exactly it is better than TLS or
>>>>>> XMLDSIG.
>>>>>>
>>>>>> While SimpleSign is designed to be easy to implement, it still has
>>>>>> less implementations than TLS, or even XMLDSIG. There is also less
>>>>>> existing security analysis, test cases, &c.
>>>>>>
>>>>>> The certificate from SimpleSign is X509, so depends upon the support
>>>>>> of a CA. A certificate will only be valid if the subject applies to
>>>>>> the CannonicalID. Getting such a certificate will cost the same as a
>>>>>> TLS certificate, if they are not the identical.
>>>>>>
>>>>>> Why should I use a SimpleSign implementation instead of TLS or
>>>>>> XMLDSIG?
>>>>>>
>>>>>> Some possible answers:
>>>>>> * You shouldn't. (NO!!!)
>>>>>> * Using TLS would require either all resources must be encrypted and
>>>>>> sign (significant overhead), or that the XRD must be available under
>>>>>> TLS while other resources may not (significant complexity).
>>>>>>  * Using TLS means that an XRD cannot be provided under restrictive
>>>>>> hosting environments, as it cannot be implemented by uploading a PHP
>>>>>> script over FTP.
>>>>>> * Using XMLDSIG requires either a custom implementation (error
>>>>>> prone), or support for a known-good implementation (restricted
>>>>>> environments).
>>>>>> * SimpleSign is simple enough that an amateur can implement it
>>>>>> without worry of error, is easy to host, and allows flexible security
>>>>>> for other resources.
>>>>>>
>>>>>> http://josephholsten.com
>>>>>>
>>>>>> PS. I'm still trying to get up to speed with everything in XRI, so
>>>>>> I'm sorry if I ask silly questions
>>>>>>
>>>>>> ---------------------------------------------------------------------
>>>>>> To unsubscribe from this mail list, you must leave the OASIS TC that
>>>>>> generates this mail.  Follow this link to all your TCs in OASIS at:
>>>>>> https://www.oasis-open.org/apps/org/workgroup/portal/my_workgroups.php
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>> ---------------------------------------------------------------------
>>>>> To unsubscribe from this mail list, you must leave the OASIS TC that
>>>>> generates this mail.  Follow this link to all your TCs in OASIS at:
>>>>> https://www.oasis-open.org/apps/org/workgroup/portal/my_workgroups.php
>>>>>
>>>>>
>>>
>>
>> ---------------------------------------------------------------------
>> To unsubscribe from this mail list, you must leave the OASIS TC that
>> generates this mail.  Follow this link to all your TCs in OASIS at:
>> https://www.oasis-open.org/apps/org/workgroup/portal/my_workgroups.php
>>
>>
>>
>
>


[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]