Hi Wang Hao, The use of GraphicString for ObjectDescriptor is for historical reasons. Unfortunately in cannot be changed now without breaking backward compatibility.
Please note, however, that ObjectDescriptor is used purely for documentation purposes (for a corresponding OBJECT IDENTIFIER). I have not seen any specification actually transmit ObjectDescriptors in their exchanges. They transmit only the OBJECT IDENTIFIERs. Given that, I don't believe you need to be concerned about ObjectDescriptor continuing to reference GraphicString since it is not normally transmitted. ---------------------------------------------------------------------------- Paul E. Thorpe Toll Free : 1-888-OSS-ASN1 OSS Nokalva International: 1-732-302-0750 Email: [EMAIL PROTECTED] Tech Support : 1-732-302-9669 http://www.oss.com Fax : 1-732-302-0023 On Tue, 7 Sep 2004, WangHao wrote: > Hi, > > According to books by John L and Olivier, GraphicString type is not recommended > to use because no ASN.1 tool takes fully account into it. However, the > ObjectDescriptor > type is defined as "[UNIVERSAL 7] IMPLICIT GraphicString" in X.680. Does anynoe know > what the exact > reason is? > > If abstract values of ObjectDescripor type consist of only characters from > BasicLatin(or > ASCII), that's fine and encodings can be done using encoding rules of IA5String(the > encoding > is 8 bits per character and maybe less in PER). Is it right? If not, that is to say > that the abstract value > may be a string of other kind of characters such as Chinese characters. However, it > is difficult for an ASN.1 > tool to deal with such an ever-expanding character string type to support > GraphicString type completely. > > If the values of ObjectDecriptor can be formed from any valid international > character, why not define the > ObjectDecriptor type as "[UNIVERSAL 7] IMPLICIT BMPString(or UTF8String)"? > > Thanks for any reply in advance! > > Regards, > > Wang Hao > _______________________________________________ ASN1 mailing list [EMAIL PROTECTED] http://lists.asn1.org/mailman/listinfo/asn1
