MD5 Filter

The foglamp-filter-md5 plugin computes a MD5 hash of a reading’s JSON representation and stores the hash as a new datapoint within the reading. This allows verification of the data integrity in order to detect potential modifications to the data later in the data pipeline.

This filter is useful for:

  • Verifying if readings have been modified since the point in the pipeline at which the filter added the MD5.

  • Providing a mechanism to verify whether a reading has been altered.

  • Enabling data tampering detection when used alongside foglamp-filter-md5verify.

The name of the datapoint to which the MD5 hash is written can be set via the plugin configuration. The default datapoint name is MD5.

Note

The MD5 hash includes the name and value of all datapoints in the reading. This ensures name changes, value changes, addition or removal of a datapoint will be detected.

Adding the MD5 Filter

MD5 filters are added in the same way as any other filters:

md5

  • MD5 Datapoint Name : Name for the data point to hold the MD5 hash value

  • Enabled : Enable or Disable Filter

  • Click Done to activate it