Hi What I would like to do is to extract the payload from the PER encoded PDU then encrypt it and replace the payload in the PDU with the encrypted "payload". This way of describing data with different views requires something like a "C" UNION functionality. Is this available in ASN.1?
How is this normally treated in a ASN1 specification? The padding is needed since I currently operate on the PER encoded data when I replace the payload the size of it must fit with the block size of encryption algorithm. /Henrik Andersson -----Original Message----- From: Conrad Sigona [mailto:[EMAIL PROTECTED] Sent: den 2 december 2006 12:22 To: Andersson Henrik Cc: [email protected] Subject: Re: [Asn1] Temporarily encrypt part of a ASN.1 module > I have designed an ASN.1 module. When this module is transmitted a part > of it shall be encrypted. I wonder if there is a nice way to handle this > in ASN.1. I have included a simplified module below to describe the > problem. > > PDU::= SEQUENCE { > header Header, > payload Payload - -this part shall be encrypted during transfer > } > > Payload SEQUENCE { > dataA INTEGER, > dataB INTEGER, > padding OCTETSTRING > } > > During transfer the Payload shall be encrypted. In my current solution I > have been forced to add a padding field to make sure that the data size > fits with the encryption algorithm. I presume that there is a better way > to describe this with ASN.1. Please be a little more precise. Is it that Payload, as a SEQUENCE, would be encrypted and inserted into PDU as something else (not a SEQUENCE), or rather that dataA and dataB are each encrypted and inserted into Payload. Please also explain the point of padding. Is it that the encryption algorithm only accepts fixed size blocks? ===================================================================== Conrad Sigona Voice Mail : 1-732-302-9669 x400 OSS Nokalva Fax : 1-614-388-4156 [EMAIL PROTECTED] My direct line : 1-315-845-1773 _______________________________________________ Asn1 mailing list [email protected] http://lists.asn1.org/mailman/listinfo/asn1
