Re: time-stamp-draft-7

[Denis Pinkas <Denis.Pinkas@xxxxxxxx>]

Joerg,

Thanks for your careful writing. We came form a maximum tagging
version (which was safe) to a minimum one. It is hard to do minimal
tagging by thinking to all the various combinations.

You are right. Thanks for providing a change proposal.

Denis
 
> Denis,
> 
> maybe the TSTInfo structure has some inconvenience because of the missing tags
> now:
> 
> time-stamp-draft-7: IMPLIZIT tagging
> 
> TSTInfo ::= SEQUENCE  {
>         [...]
>      tsa                          GeneralName          OPTIONAL,
>      extensions                   [0] Extensions       OPTIONAL
> }
> 
> X.509 IMPLIZIT: Tagging:
> 
>       GeneralName ::= CHOICE {
>            otherName                       [0]     OtherName,
>            rfc822Name                      [1]     IA5String,
>            dNSName                         [2]     IA5String,
>            x400Address                     [3]     ORAddress,
>            directoryName                   [4]     Name,
>            ediPartyName                    [5]     EDIPartyName,
>            uniformResourceIdentifier       [6]     IA5String,
>            iPAddress                       [7]     OCTET STRING,
>            registeredID                    [8]     OBJECT IDENTIFIER}
> 
>       OtherName ::= SEQUENCE {
>            type-id    OBJECT IDENTIFIER,
>            value      [0] EXPLICIT ANY DEFINED BY type-id }
> 
>    Extensions  ::=  SEQUENCE SIZE (1..MAX) OF Extension
> 
> The parser can't ditinguish between the "GeneralName" field and "[0]
> Extensions" in case that the GeneralName choice is "[0] OtherName". Since both
> OtherName and Extensions are sequences the tag will be encoded identically and
> can't be used to distinguish the two optional entries. They could only
> distinguished by checking the tag of the content of the sequence. That isn't
> very convinient for implementations.
> 
> I suggest changing the tagging to:
> 
> TSTInfo ::= SEQUENCE  {
>     [...]
>      tsa                          [0] GeneralName      OPTIONAL,
>      extensions                   [1] Extensions       OPTIONAL
> }
> 
> Jorg
> 
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