tinydmarc

A tiny "functionally minimalist" DMARC aggregate report summarizer.

What is it?

tinydmarc is a small, simple CLI that can read in a set of DMARC Aggregate Report XML files and generates a report, broken down by week and receiving domain, with the number of emails "rejected" and "not rejected" by each domain in that week.

What isn't it?

This is in no way a "feature rich" tool for processing DMARC reports!

• It does not handle many error cases
• It does not handle DMARC Forensic reports
• It does not draw any charts
• It does not handle non-standard Aggregate Report files
• It does not retrieve the report files from an email account
• It does not handle time zones

tinydmarc does the bare minimum of what I want, and was mostly an exercise in learning the basics of Rust. If you want an awesome, fully functional DMARC solution, then check out parsedmarc. If you just want to check if your DMARC reports show any rejected messages recently then maybe tinydmarc is for you.

What does it do?

tinydmarc takes as input a directory containing a set of DMARC Aggregate Reports. It reads in all of the reports, then assigns them to a week-long time bucket running from Sunday to Sunday, using the value from feedback.report_metadata.date_range.begin.

It then loops through each time bucket and processes all of the reports in that bucket. For each report, it iterates through each feedback.record and counts how many messages have record.row.policy_evaluated.disposition equal to "none" (counting as a "good" message) and how many do not (counting as a "bad" message). It then generates a report with a weekly breakdown of how many messages each receiving domain reported as "good" and "bad".

The report can be printed to STDOUT or written to a file, and the report format can be one of txt, html and JSON.

How do I use it?

$ tinydmarc --help
Tiny DMARC Report Generator 0.0.1
Scans all DMARC XML reports in a folder and generates a simple HTML report

USAGE:
    tinydmarc [FLAGS] [OPTIONS] --inputDir <INPUTDIR>

FLAGS:
    -h, --help       Prints help information
    -v               Sets the level of verbosity (-vvv is trace)
    -V, --version    Prints version information

OPTIONS:
    -o, --outputFormat <FORMAT>      Sets the output file format [default: txt]  [possible values: html, txt, json]
    -i, --inputDir <INPUTDIR>        Sets the directory containing the DMARC reports
    -f, --outputFile <OUTPUTFILE>    Sets the output file to write to

Print out a summary to STDOUT

$> tinydmarc --inputDir path/to/dmarc/reports/
DMARC REPORT GENERATED AT 2020-12-14T23:02:36.546142100+00:00
===
Date: Sun 22 November - Sat 28 November
Domain: "google.com" - Good: 6 - Bad: 0
---
Date: Sun 29 November - Sat  5 December
Domain: "Yahoo! Inc." - Good: 6 - Bad: 0
Domain: "google.com" - Good: 40 - Bad: 0
---

Write an HTML report to a file

$> tinydmarc --inputDir path/to/dmarc/reports/ --outputFile path/to/report.html -o html

which may produce:

License

Do what you want with it!