Re: MD5 value security consideration

At 10:03 04/03/99 -0800, Bill Newman wrote:
>Graham Klyne wrote
>
>> I noticed this in a recent I-D, and thought it might appropriate to mention
>> something similar in the security considerations of our drafts that suggest
>> use of MD5.
>> 
>>    Implementations should take care not to assume that the value of the
>>    Content-MD5: header will always be 24 bytes or less - to avoid buffer
>>    overrun problems.  It would also be unwise to assume that the
>>    characters in an arbitrary Content-MD5: header will be chosen from
>>    the base64 character set mandated by RFC 1864.
>
>Perhaps I'm missing something, but this doesn't look like a special
>security consideration.  It seems to me that in both your I-D and
>mine, the possibility of buffer overflow or unexpected characters for
>hash values has the same security consequences as any other buffer
>overflow ...

I think you're right.  It's just that enough security holes have been
caused by implementation weaknesses in this area that it probably doesn't
harm to remind imlementers at every opportunity.

#g


------------
Graham Klyne
([email protected])