If you want to hash multiple data sources (such as several database fields) into a single message digest, you can marshall the individual data sources into a single MEMPTR variable using the PUT-datatype functions before invoking the message digest function. To make this work correctly, you must marshall exactly the same data sources using exactly the same order and data formats to generate comparable digests.

Because message digests are generated as a RAW binary byte stream, you must ensure that the byte endian order is maintained cross different hardware platforms.

The management considerations for message digest keys and results is much the same as for any encryption keys and data, except that you do not have to keep track of the code page of data sources. For more information, see Managing and transporting crypto data.