Subject: Re: [dispatch] Proposed charter for DCRUP v0.2

From: Federico Santandrea <[email-masked]>
Date: Tue, 4 Apr 2017 11:51:33 +0200

I'd suggest:

"bugs in DNS provisioning software" ->
   "limits in some DNS provisioning software".

On 30/03/2017 21:37, John R Levine wrote:
> 1024 bit signatures are common, longer signatures are not because bugs in
> DNS provisioning software prevent publishing longer keys as DNS TXT
> records.

-- 
Federico

---

From: "John Levine" <[email-masked]>
Date: 4 Apr 2017 16:19:17 -0000

>   "limits in some DNS provisioning software".

I'd say that if provisioning software claims to handle TXT records but
only handles a single string, that's a bug.  I realize it's a bug that
is not likely to get fixed any time soon, but bugs can be like that.

R's,
John

---

From: "John Levine" <[email-masked]>
Date: 6 Apr 2017 23:32:14 -0000

Scott Rose submitted this draft with suggested new algorithms for DCRUP.

--- snippo ---
A New Internet-Draft is available from the on-line Internet-Drafts directories.

        Title           : Defining Elliptic Curve Cryptography Algorithms for use with DKIM
        Author          : Scott Rose
        Filename        : draft-srose-dkim-ecc-00.txt
        Pages           : 6
        Date            : 2017-04-06

Abstract:
   DomainKeys Identified Mail (DKIM) uses digital signature to associate
   a message with a given sending domain.  Currently, there is only one
   cryptography algorithm defined for use with DKIM (RSA).  This
   document defines four new elliptic curve cryptography algorithms for
   use with DKIM.  This will allow for algorithm agility if a weakness
   is found in RSA, and allows for smaller key length to provide the
   same digital signature strength.

The IETF datatracker status page for this draft is:
https://datatracker.ietf.org/doc/draft-srose-dkim-ecc/

There are also htmlized versions available at:
https://tools.ietf.org/html/draft-srose-dkim-ecc-00
https://datatracker.ietf.org/doc/html/draft-srose-dkim-ecc-00

Please note that it may take a couple of minutes from the time of submission
until the htmlized version and diff are available at tools.ietf.org.

Internet-Drafts are also available by anonymous FTP at:
ftp://ftp.ietf.org/internet-drafts/
A New Internet-Draft is available from the on-line Internet-Drafts directories.

        Title           : Defining Elliptic Curve Cryptography Algorithms for use with DKIM
        Author          : Scott Rose
        Filename        : draft-srose-dkim-ecc-00.txt
        Pages           : 6
        Date            : 2017-04-06

Abstract:
   DomainKeys Identified Mail (DKIM) uses digital signature to associate
   a message with a given sending domain.  Currently, there is only one
   cryptography algorithm defined for use with DKIM (RSA).  This
   document defines four new elliptic curve cryptography algorithms for
   use with DKIM.  This will allow for algorithm agility if a weakness
   is found in RSA, and allows for smaller key length to provide the
   same digital signature strength.

The IETF datatracker status page for this draft is:
https://datatracker.ietf.org/doc/draft-srose-dkim-ecc/

There are also htmlized versions available at:
https://tools.ietf.org/html/draft-srose-dkim-ecc-00
https://datatracker.ietf.org/doc/html/draft-srose-dkim-ecc-00

Please note that it may take a couple of minutes from the time of submission
until the htmlized version and diff are available at tools.ietf.org.

Internet-Drafts are also available by anonymous FTP at:
ftp://ftp.ietf.org/internet-drafts/
A New Internet-Draft is available from the on-line Internet-Drafts directories.

        Title           : Defining Elliptic Curve Cryptography Algorithms for use with DKIM
        Author          : Scott Rose
        Filename        : draft-srose-dkim-ecc-00.txt
        Pages           : 6
        Date            : 2017-04-06

Abstract:
   DomainKeys Identified Mail (DKIM) uses digital signature to associate
   a message with a given sending domain.  Currently, there is only one
   cryptography algorithm defined for use with DKIM (RSA).  This
   document defines four new elliptic curve cryptography algorithms for
   use with DKIM.  This will allow for algorithm agility if a weakness
   is found in RSA, and allows for smaller key length to provide the
   same digital signature strength.

The IETF datatracker status page for this draft is:
https://datatracker.ietf.org/doc/draft-srose-dkim-ecc/

There are also htmlized versions available at:
https://tools.ietf.org/html/draft-srose-dkim-ecc-00
https://datatracker.ietf.org/doc/html/draft-srose-dkim-ecc-00

Please note that it may take a couple of minutes from the time of submission
until the htmlized version and diff are available at tools.ietf.org.

Internet-Drafts are also available by anonymous FTP at:
ftp://ftp.ietf.org/internet-drafts/
A New Internet-Draft is available from the on-line Internet-Drafts directories.

        Title           : Defining Elliptic Curve Cryptography Algorithms for use with DKIM
        Author          : Scott Rose
        Filename        : draft-srose-dkim-ecc-00.txt
        Pages           : 6
        Date            : 2017-04-06

Abstract:
   DomainKeys Identified Mail (DKIM) uses digital signature to associate
   a message with a given sending domain.  Currently, there is only one
   cryptography algorithm defined for use with DKIM (RSA).  This
   document defines four new elliptic curve cryptography algorithms for
   use with DKIM.  This will allow for algorithm agility if a weakness
   is found in RSA, and allows for smaller key length to provide the
   same digital signature strength.

The IETF datatracker status page for this draft is:
https://datatracker.ietf.org/doc/draft-srose-dkim-ecc/

There are also htmlized versions available at:
https://tools.ietf.org/html/draft-srose-dkim-ecc-00
https://datatracker.ietf.org/doc/html/draft-srose-dkim-ecc-00

Please note that it may take a couple of minutes from the time of submission
until the htmlized version and diff are available at tools.ietf.org.

Internet-Drafts are also available by anonymous FTP at:
ftp://ftp.ietf.org/internet-drafts/
A New Internet-Draft is available from the on-line Internet-Drafts directories.

        Title           : Defining Elliptic Curve Cryptography Algorithms for use with DKIM
        Author          : Scott Rose
        Filename        : draft-srose-dkim-ecc-00.txt
        Pages           : 6
        Date            : 2017-04-06

Abstract:
   DomainKeys Identified Mail (DKIM) uses digital signature to associate
   a message with a given sending domain.  Currently, there is only one
   cryptography algorithm defined for use with DKIM (RSA).  This
   document defines four new elliptic curve cryptography algorithms for
   use with DKIM.  This will allow for algorithm agility if a weakness
   is found in RSA, and allows for smaller key length to provide the
   same digital signature strength.

The IETF datatracker status page for this draft is:
https://datatracker.ietf.org/doc/draft-srose-dkim-ecc/

There are also htmlized versions available at:
https://tools.ietf.org/html/draft-srose-dkim-ecc-00
https://datatracker.ietf.org/doc/html/draft-srose-dkim-ecc-00

Please note that it may take a couple of minutes from the time of submission
until the htmlized version and diff are available at tools.ietf.org.

Internet-Drafts are also available by anonymous FTP at:
ftp://ftp.ietf.org/internet-drafts/

---

From: "John R Levine" <[email-masked]>
Date: 7 Apr 2017 12:36:18 -0400

One last twiddle, make it clear we can deprecate obsolete signing 
algorithms.  I have in mind SHA-1 and RSA-512.

Assuming people are happy with this, what's the next step?

R's,
John

-----------

The DKIM Crypto Update (DCRUP) working groupkin is chartered to update
DKIM to handle more modern cryptographic algorithms and key sizes. DKIM
(RFC 6376) signatures include a tag that identifies the hash algorithm and
signing algorithm used in the signature. The only current algorithm is RSA,
with advice that signing keys should be between 1024 and 2048 bits. While
1024 bit signatures are common, longer signatures are not because bugs in
DNS provisioning software prevent publishing longer keys as DNS TXT records.

DCRUP will consider three types of changes to DKIM: additional signing 
algorithms such as those based on elliptic curves, changes to key strength 
advice and requirements including deprecating obsolete algorithms, and new 
public key forms, such as putting the public key in the signature and a 
hash of the key in the DNS.  It will limit itself to existing implemented 
algorithms and key forms. Other changes to DKIM, such as new message 
canonicalization schemes, are out of scope.  The WG will as far as 
possible avoid changes incompatible with deployed DKIM signers and 
verifiers.

---

From: Eric Rescorla <[email-masked]>
Date: Fri, 7 Apr 2017 09:41:15 -0700

On Fri, Apr 7, 2017 at 9:36 AM, John R Levine <[email-masked]> wrote:

> algorithms and key forms.

Can you clarify "implemented" here? Do you just mean "in wide use by IETF
or otherwise"?

-Ekr

Other changes to DKIM, such as new message canonicalization schemes, are
> out of scope.  The WG will as far as possible avoid changes incompatible
> with deployed DKIM signers and verifiers.
>
> _______________________________________________
> dispatch mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/dispatch
>

---

From: "John R Levine" <[email-masked]>
Date: 7 Apr 2017 12:51:36 -0400

> Can you clarify "implemented" here? Do you just mean "in wide use by IETF

That's essentially what I had in mind.  Freely available high quality 
imeplmentations would be nice.

Regards,
John Levine, [email-masked], Taughannock Networks, Trumansburg NY
Please consider the environment before reading this e-mail. https://jl.ly

---

From: Eric Rescorla <[email-masked]>
Date: Fri, 7 Apr 2017 09:53:38 -0700

> imeplmentations would be nice.

The only reason I mentioned this is that one might think that this meant
"implemented in DKIM". Do you think "limit itself to algorithms and
key forms generally in use in the IETF"? would be clearer?

-Ekr

---

From: "John R Levine" <[email-masked]>
Date: 7 Apr 2017 13:06:12 -0400

> key forms generally in use in the IETF"? would be clearer?

Sure, why not.

R's,
John