The format of the name of each generated OER encode function is as follows:

   OEREnc_[<prefix>]<prodName>

where <prodName> is the name of the ASN.1 production for which the function is being generated and <prefix> is an optional prefix that can be set via a configuration file setting. The configuration setting used to set the prefix is the <typePrefix> element. This element specifies a prefix that will be applied to all generated typedef names and function names for the production.

The calling sequence for each encode function is as follows:

   status = OEREnc_<name> (OSCTXT* pctxt, <name>[*] value);

In this definition, <name> denotes the prefixed production name defined above.

The pctxt argument is used to hold a context pointer to keep track of encode parameters. This is a basic "handle" variable that is used to make the function reentrant so it can be used in an asynchronous or threaded application. The user is required to supply a pointer to a variable of this type declared somewhere in his or her program.

The value argument contains the value to be encoded or holds a pointer to the value to be encoded. This variable is of the type generated from the ASN.1 production. The object is passed by value if it is a primitive ASN.1 data type such as BOOLEAN, INTEGER, ENUMERATED, etc.. It is passed using a pointer reference if it is a structured ASN.1 type value. Check the generated function prototype in the header file to determine how the value argument is to be passed for a given function.

The function result variable stat returns the status of the encode operation. Status code 0 (0) indicates the function was successful. Note that this return value differs from that of BER encode functions in that the encoded length of the message component is not returned – only an OK status indicating encoding was successful. A negative value indicates encoding failed. Return status values are defined in the "asn1type.h" include file. The error text and a stack trace can be displayed using the rtxErrPrint function.

If the code is generated using the -coer switch, then the encoding will be canonical. If the code is generated using the -oer switch, the encoding can be made canonical by setting the appropriate flag in the context prior to calling the encode function:

   rtxCtxtSetFlag(pctxt, ASN1CANON);