30.1. EVE JSON Schema

The Suricata source distribution contains a JSON schema for the EVE log files. This schema follows the JSON Schema specification and can be found in etc/schema.json. If your distribution does not contain this file, it can be viewed online at https://github.com/OISF/suricata/blob/main/etc/schema.json, but note that it is version-specific and may change between major versions of Suricata.

This schema attempts to log all possible fields that may be seen in Suricata's EVE output, including their datatype. It also includes extensions to help map log fields to related detection keywords.

30.1.1. Suricata Schema Extensions

We have extended JSON schema with a suricata object to add extra Suricata context such as detection keywords related to a log field, for example:

"rrname": {
    "type": "string",
    "suricata": {
        "keywords": [
            "dns.answers.rrname",
            "dns.response.rrname"
        ]
    }
}

The above shows that a field named rrname has 2 keywords that are related. Please refer to the keyword documentation to see precisely how they are used and related to the field being logged.

30.1.1.1. Extension Reference

The suricata extension object is valid on objects inside the properties object. The suricata object may accept the following fields:

30.1.1.1.1. keywords

Type: array or boolean

  • When an array: Contains keyword names that are related to this JSON property. Each keyword in the array represents a detection rule keyword that can be used to match against the corresponding field value.

  • When ``false``: Indicates that this JSON property has no applicable keyword. This is used for metadata fields that don't correspond to actual network data. For example, the version field inside a DNS object denotes the version of the log format and is unrelated to any aspect of a DNS message, therefore no keyword is applicable.

Note

As of Suricata 8.0, mapping log fields to detection keywords is a work in progress. Any field that does not have a suricata.keywords value still needs to be evaluated.

30.1.2. Schema Tooling

  • Suricata-Verify: Our own tool for verifying every Suricata pull request, validates all EVE logs generated against the schema.

  • ./scripts/eve-parity.py: Found inside the Suricata source code when checked out with git, is a tool to provide information on how log fields map to keywords, or how keywords map to log entries.

  • ./scripts/evedoc.py: Generate documentation from the schema, such as the EVE Index included in this documentation.