ietf-smime
[Top] [All Lists]

S/MIME X.400 Transport

2001-08-14 02:34:40

Hello everybody

                I need some clarifications regarding the transport of S/MIME
in X.400 as
per the draft  "draft-ietf-smime-x400transport-03.txt". The draft says that
one should have 
a separate content to represent the CMS object. The "content-type" field of
P1 envelope 
should contain the CMS defined value:

id-data OBJECT IDENTIFIER ::= { iso(1) member-body(2) us(840) rsadsi(113549)
pkcs(1) 
                                                       pkcs7(7) 1 }

if the CMS object is covered by outer MIME wrapper and should contain value:

id-ct-contentInfo  OBJECT IDENTIFIER ::= { iso(1) member-body(2)  us(840)
rsadsi(113549) 
                                                          pkcs(1) pkcs-9(9)
smime(16) content-types(1) 6 }

if the CMS object is not covered by an outer MIME wrapper.

        The draft also says that, In case the S/MIME message is forwarded,
the CMS object
should be a bodypart of the "Forwarded IPM".


        X.400 recommendations define different content types with
Interpersonal Message (IPM)
and EDI to quote as some examples. Our X400 MTA/Gateway implementation uses
APIs  as
specified by Xopen Group http://www.opengroup.org/  i.e. XAPIs to build an
IPM.

        The XAPI document also defines and describes a content type called
the "General Content" 
type with binary data being its content. Since CMS object is a binary, can
we use this content type
to convey CMS objects? and can I assume that the receiving User Agent (UA)
will be 
responsible to interpret the message as secure one?


The layout of the message will be as follows:

            __________________________________
        |   P1 Envelope                         |
        |   containing S/MIME oid               |
        |                                       |
        |-----------------------------------------------------------    |
        |    General Content Type               |
        |                                       |
        |    with CMS object being the binary   |
        |    data.                              |
        |                                       |
        |__________________________________|

Following is the dump of the message as seen in X.400:
----------------------------------------------------------------------------
---------------------------------
        XAPI dump of a General content message with CMS object
                        being the content
----------------------------------------------------------------------------
---------------------------------

OM_CLASS [OM_S_OBJECT_IDENTIFIER_STRING]: MH_C_DELIV_MESSAGE
MH_T_CONTENT [OM_S_OBJECT]: (Object)
      OM_CLASS [OM_S_OBJECT_IDENTIFIER_STRING]: MH_C_GENERAL_CONTENT
<< The above OID indicates that it is a general content>>

      MH_T_BINARY_CONTENT [OM_S_OCTET_STRING]: Long string.
<< Binary CMS object follows here >>
30 80  6  9 2a 86 48 86 f7  d  1  7  2 a0 80 30 80  2  1  1 0...*.H.÷....
.0....
31  b 30  9  6  5 2b  e  3  2 1a  5  0 30 80  6  9 2a 86 48
1.0...+......0...*.H
86 f7  d  1  7  1 a0 80 24 80  4  c 43 6f 6e 74 65 6e 74 2d .÷....
.$...Content-
<< More data follows here ...but removed >>.
33 b2 bd ed 85 19 af 77 9d 5c 62 9d 1b b1 ab 19 bb 36 26 5c
3²½í..¯w.\b..±«.»6&\
6f  d 37 a6 99 90 82 6c  0  0  0  0  0  0  0  0  0  0  0  0
o.7¦...l............
Total Length 3394
<< Envelope starts from here >>
MH_T_ENVELOPES [OM_S_OBJECT]: (Object)
      OM_CLASS [OM_S_OBJECT_IDENTIFIER_STRING]: MH_C_DELIVERY_ENVELOPE
      MH_T_ACTUAL_RECIPIENT_NAME [OM_S_OBJECT]: (Object)
            OM_CLASS [OM_S_OBJECT_IDENTIFIER_STRING]: MH_C_OR_NAME
            MH_T_ADMD_NAME [OM_S_PRINTABLE_STRING]: vsnl
            MH_T_COMMON_NAME [OM_S_PRINTABLE_STRING]: test
            MH_T_COUNTRY_NAME [OM_S_PRINTABLE_STRING]: in
            MH_T_ORGANIZATION_NAME [OM_S_PRINTABLE_STRING]: idc
            MH_T_PRMD_NAME [OM_S_PRINTABLE_STRING]: digital
      MH_T_BUREAU_FAX_DELIVERY [OM_S_BOOLEAN]: OM_FALSE
      MH_T_CONTENT_TYPE [OM_S_OBJECT_IDENTIFIER_STRING]: 
ObjID: 2a 86 48 86 f7 0d 01 09 10 0106
<< The above OID is the OID for S/MIME (unwrapped) >>

      MH_T_CONVERSION_LOSS_PROHIBITED [OM_S_BOOLEAN]: OM_FALSE
      MH_T_CONVERSION_PROHIBITED [OM_S_BOOLEAN]: OM_FALSE
      MH_T_DELIVERY_TIME [OM_S_UTC_TIME_STRING]: 010809152452Z
      MH_T_FORWARDING_ADDR_REQUESTED [OM_S_BOOLEAN]: OM_FALSE
      MH_T_FORWARDING_PROHIBITED [OM_S_BOOLEAN]: OM_FALSE
      MH_T_MTS_IDENTIFIER [OM_S_OBJECT]: (Object)
            OM_CLASS [OM_S_OBJECT_IDENTIFIER_STRING]: MH_C_MTS_IDENTIFIER
            MH_T_ADMD_NAME [OM_S_PRINTABLE_STRING]: vsnl
            MH_T_COUNTRY_NAME [OM_S_PRINTABLE_STRING]: in
            MH_T_LOCAL_IDENTIFIER [OM_S_IA5_STRING]:
9B265BAE11D58CDA00001590
            MH_T_PRMD_IDENTIFIER [OM_S_PRINTABLE_STRING]: digital
      MH_T_ORIGINATOR_NAME [OM_S_OBJECT]: (Object)
            OM_CLASS [OM_S_OBJECT_IDENTIFIER_STRING]: MH_C_OR_NAME
            MH_T_ADMD_NAME [OM_S_PRINTABLE_STRING]: vsnl
            MH_T_COMMON_NAME [OM_S_PRINTABLE_STRING]: nandi
            MH_T_COUNTRY_NAME [OM_S_PRINTABLE_STRING]: in
            MH_T_ORGANIZATION_NAME [OM_S_PRINTABLE_STRING]: idc
            MH_T_PRMD_NAME [OM_S_PRINTABLE_STRING]: digital
      MH_T_POSTAL_REPORT [OM_S_ENUMERATION]: MH_PR_UNDELIVBLE_MAIL_VIA_PDS
      MH_T_PREFERRED_DELIVERY_MODES [OM_S_ENUMERATION]: MH_DM_ANY
      MH_T_PRIORITY [OM_S_ENUMERATION]: MH_PTY_NORMAL
      MH_T_PROOF_OF_DELIV_REQUESTED [OM_S_BOOLEAN]: OM_FALSE
      MH_T_REGISTRATION [OM_S_ENUMERATION]: 0
      MH_T_RENDITION_ATTRIBUTES [OM_S_OBJECT_IDENTIFIER_STRING]:
MH_RA_BASIC_RENDITION
      MH_T_SUBMISSION_TIME [OM_S_UTC_TIME_STRING]: 010809152421Z
----------------------------------------------------------------------------
---------------------------------

        Could anybody comment on the usage of General content in the
transfer
of CMS object from MIME to X.400.

Regards
Nandi




<Prev in Thread] Current Thread [Next in Thread>