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RE: ACTION-303 Correct doc on length of r and s

From: Kelvin Yiu <kelviny@exchange.microsoft.com>
Date: Mon, 8 Jun 2009 15:45:50 -0700
To: Pratik Datta <pratik.datta@oracle.com>
CC: "public-xmlsec@w3.org" <public-xmlsec@w3.org>
Message-ID: <EF8BB8116404AE42A67EF8BECBC14487BE20D25F@DF-POINTER-MSG.exchange.corp.microsoft.com>
Sounds good to me. Text updated to the following:

Integer to octet-stream conversion must be done according to the I2OSP operation defined in the RFC 2437 [ PKCS1 ] specification with the l parameter equal to the size of the base point order of the curve in bytes (e.g. 32 for the P-256 curve and 66 for the P-521 curve).

Kelvin

-----Original Message-----
From: Pratik Datta [mailto:pratik.datta@oracle.com] 
Sent: Monday, June 08, 2009 2:47 PM
To: Kelvin Yiu
Cc: public-xmlsec@w3.org
Subject: Re: ACTION-303 Correct doc on length of r and s

Suggested text:

Integer to octet-stream conversion must be done according to the I2OSP 
operation defined in the RFC 2437 [ PKCS1 ] specification with the l 
parameter equal to the size of the base point order of the curve rounded 
up to bytes (e.g. 66 for the P-521 curve).

Pratik Datta wrote:
> Although it is probably obvious, I would prefer that we make it 
> explicit that one needs to round up when converting length in bits to 
> bytes. Also using P-521 as an example instead of P-256 will illustrate 
> this rounding up.
>
> Pratik
>
> Kelvin Yiu wrote:
>> The text in section 6.4.3 has been updated from:
>>
>> Integer to octet-stream conversion must be done according to the 
>> I2OSP operation defined in the RFC 2437 [ PKCS1 ] specification with 
>> the l parameter equal to the size of the output of the digest 
>> function in bytes (e.g. 32 for SHA-256).
>>
>> to:
>>
>> Integer to octet-stream conversion must be done according to the 
>> I2OSP operation defined in the RFC 2437 [ PKCS1 ] specification with 
>> the l parameter equal to the size of the base point order of the 
>> curve in bytes (e.g. 32 for the P-256 curve).
>>
>> Comments?
>>
>> Kelvin
>>
>>   
>
>
Received on Monday, 8 June 2009 22:47:42 GMT

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