Ed Day wrote: The bytes are in big-endian order (most significant first).
I think you might ignore something. Just as Piotr said, little endian is preferred in some situation although most of standard protocol is of big endian. According to my experience in constructing testing system, some private interface messages are tranfered in little endian. However, we have to monitor and test the private protocol interface, so our ASN.1 testing tool team extends the standard ASN.1 notation to allow users to specify the endian control. Thus, our tools are able to encode and decode the message as users expect. Wang Hao ----- Original Message ----- From: "Ed Day" <[EMAIL PROTECTED]> To: "Piotr Stefanski" <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]> Sent: Tuesday, August 24, 2004 9:49 PM Subject: Re: [ASN1] What is the bytes order in ASN.1 message? > Hi Piotr, > > The bytes are in big-endian order (most significant first). But there is > more to it than that. The contents are variable length as well, so direct > assignment to an integer type variable on a given system is most likely not > going to work. You need to process each byte separately and either shift or > multiply by 256 to get the correct value on any given platform. And you > need to take into account the leading bit to determine if you have a > positive or negative number. > > Regards, > > Ed Day > Objective Systems, Inc. > http://www.obj-sys.com > > > ----- Original Message ----- > From: "Piotr Stefanski" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Monday, August 23, 2004 6:53 AM > Subject: [ASN1] What is the bytes order in ASN.1 message? > > > > Hi All! > > > > It was a long time before I decided to write to you > > this e-mail. > > Finally I decided to write to you as I am a little bit > > confused with this "BIG/LITTLE ENDIAN" issues in ASN.1 > > > > ASN.1 is the standard for communication between > > heterogeneous systems. > > What means also that it "doesn't care" about diversity > > of machine architectures. > > OK. So let's say sender machine encodes some messages > > in ASN.1 and send it on the wire. > > WHAT IS THE STANDARD FOR BYTES ORDER IN ENCODED ASN.1 > > MESSAGE? > > Does this ASN.1 standard assume that for example > > mesage should be encoded in big/little endian format > > before sending > > the message in the wire ? > > > > I am asking about this because I am trying to write > > decoding asn.1 function for lenght of TLV and I don't > > know > > if I should check the format (big/little endian) of > > incoming asn.1 binaries first or I can assume already > > that incoming > > asn.1 mesage is in big/little endian format? > > > > Thanks for any kind of explanation ;) > > > > Best regards, > > > > Piotr > > > > > > > > > > _______________________________ > > Do you Yahoo!? > > Win 1 of 4,000 free domain names from Yahoo! Enter now. > > http://promotions.yahoo.com/goldrush > > _______________________________________________ > > ASN1 mailing list > > [EMAIL PROTECTED] > > http://lists.asn1.org/mailman/listinfo/asn1 > > > > > > _______________________________________________ > ASN1 mailing list > [EMAIL PROTECTED] > http://lists.asn1.org/mailman/listinfo/asn1 _______________________________________________ ASN1 mailing list [EMAIL PROTECTED] http://lists.asn1.org/mailman/listinfo/asn1
