Subject: [Ietf-behave] Qeustion about A1(using MD5) as HMAC key in 3489bis-03

From: "Derek MacDonald" <[email-masked]>
Date: Mon, 27 Mar 2006 13:14:16 -0800 (PST)

<span style='font-size:10.0pt;
font-family:Arial'>In Section 8.1.2 point 3 the draft states:

<span style='font-size:10.0pt;
font-family:Arial'> 

<span style='font-size:10.0pt;
font-family:Arial'>The key for MESSAGE-INTEGRITY is MD5(unq(USERNAME-value)
":" unq(REALM-value) ":" password).

<span style='font-size:10.0pt;
font-family:Arial'> 

<span style='font-size:10.0pt;
font-family:Arial'>What isn’t clear is what MD5 is defined as, is it:

<span style='font-size:10.0pt;
font-family:Arial'> 

 <span
     style='font-size:10.0pt;font-family:Arial'>the 128 bit MD5 digest
 <span
     style='font-size:10.0pt;font-family:Arial'>the 32 ASCII printable
     characters representing the MD5 digest, as defined in rfc2617.

<span style='font-size:10.0pt;
font-family:Arial'> 

<span style='font-size:10.0pt;
font-family:Arial'>I have seen both implemented; #2 is prob. intended, as that
is what SIP element will store for 2617. 

<span style='font-size:10.0pt;
font-family:Arial'> 

<span style='font-size:10.0pt;
font-family:Arial'>--Derek