Re: example 5.2 basic signed content RSA

Wrote ronen <[email protected]>, on Wed, Jun 04, 2003 at 08:41:20AM +0300:
> i am coding CMS ( RFC3380 ) and i was parsing example 5.2 at
> draft-ietf-smime-examples-10.txt and got to the Certificate part.
> i like to know why it is SEQUENCE ( in the example ) and not SET OF  (as
> like in the CMS RFC3380 ).

It is a SET OF, except it's implicitly tagged, and the [0] tag overwrites
the SET tag. You'll need to figure out tagging to work with ASN.1.

> -------------- The start of the Certificate SET ------------------------------------------------------------
> 
>   84 A0  560:       [0] {     <--- SET OF, but implictly tagged [0]

>   88 30  556:         SEQUENCE {       <------ why not SET !!! ? ? ? ?
                             This SEQUENCE, above, is the start of the
														 X.509 Certificate, not the start of the SET
														 OF Certificate!

>   92 30  405:           SEQUENCE {
                             And this SEQUENCE is the start of the
														 TBSCertificate inside of the Certificate.
>   96 A0    3:             [0] {
>   98 02    1:               INTEGER 2
>             :               }
> 101 02   16:             INTEGER
>             :               46 34 6B C7 80 00 56 BC 11 D3 6E 2E
>             :               C4 10 B3 B0
> 119 30   13:             SEQUENCE {
> 121 06    9:               OBJECT IDENTIFIER
>             :                 sha1withRSAEncryption
>             :                     (1 2 840 113549 1 1 5)
>             :                 (PKCS #1)
> 132 05    0:               NULL
>             :               }
> 134 30   18:             SEQUENCE {
> 136 31   16:               SET {
> 138 30   14:                 SEQUENCE {
> 140 06    3:                   OBJECT IDENTIFIER
>             :                     commonName
> 

Cheers,
Sam

-- 
Sam Roberts <[email protected]>