Re: [secdir] secdir review of draft-ietf-csi-send-name-type-registry-03

[Sean Turner <[e-mail]>]

That is what, I believe, Pat was asking for.

spt

Roque Gagliano wrote:
> Stephen/ Patrick/Sean,
> 
> Thank you for your comments. What about adding the following extra
> numbers to the registry?:
> 
>   +---------+----------------------------------------------------+
>      | Value   | Description                                        |
>      +---------+----------------------------------------------------+
>      | 0       | Reserved                                           |
>      |         |                                                    |
>      | 1       | DER Encoded X.501 Name (RFC 3971)                  |
>      |         |                                                    |
>      | 2       | FQDN (RFC 3971)                                    |
>      |         |                                                    |
>      | 3       | SHA-1 Subject Key Identifier (SKI) ( Section 3 )   |
>      |         |                                                    |
>      | 4       | SHA-224 Subject Key Identifier (SKI) ( Section 3 ) |
>      |         |                                                    |
>      | 5       | SHA-256 Subject Key Identifier (SKI) ( Section 3 ) |
>      |         |                                                    |
>      | 6       | SHA-384 Subject Key Identifier (SKI) ( Section 3 ) |
>      |         |                                                    |
>      | 7       | SHA-512 Subject Key Identifier (SKI) ( Section 3 ) |
>      |         |                                                    |
>      | 253-254 | Experimental use                                   |
>      |         |                                                    |
>      | 255     | Reserved                                           |
>      +---------+----------------------------------------------------+
> 
> This way we stay ready if SIDR certs uses some of these hashes
> functions in the future.
> 
> regards,
> 
> Roque
> 
> 
> On Wed, May 12, 2010 at 8:00 PM, Stephen Kent <[e-mail]> wrote:
>> At 6:38 PM +0200 5/8/10, Roque Gagliano wrote:
>>
>> Patrick,
>>
>> Thank you for your review.
>>
>> You are correct oonly 160 bits SHA-1 hash is defined in RFC 5280 and
>> required in draft-ietf-sidr-res-cert
>>
>> Regards,
>>
>> Roque
>>
>> Roque,
>> 5280 defines how to use SHA-1, but it does not require use of this specific
>> hash function. 4.2.1.2 says:
>>    For CA certificates, subject key identifiers SHOULD be derived from the
>> public key or a method that generates unique values.  Two common methods for
>> generating key identifiers from the public key are:
>> ...
>> Other methods of generating unique numbers are also acceptable.
>> So, use of another one-way hash function, e.g., SHA-256 meets the criteria
>> defined above (associated with the "SHOULD") and is consistent with the
>> final comment.
>> CAs need to know which function to use, but RPs just perform comparisons. We
>> could modify the RPKI cert profile (if Geoff and the SIDR WG don't mind) to
>> specify use of SHA-256 for generation of SKI/AKI values. I guess the real
>> issue is whether commonly used software (e.g., OpenSSL) will support this.
>> Steve
>