TOOL

mrma: Analyze trust-boundary header influence on HTTP responses.

HTTP Trust Boundary Analyzer - replay requests, mutate headers safely, and quantify response influence.

date: 2026-03-04pinned

mrma security-tools penetration-testing python header

CONTENTS

mrma

HTTP Trust Boundary Analyzer - replay requests, mutate headers safely, and quantify response influence (authorized testing only).

mrma helps answer: “Does this target trust proxy/host headers or behave differently based on request metadata?”
It focuses on meaningful diffs (not just status/length), plus profiles that model common trust-boundary behaviors.

Start use now: Github.

Install

pipx (recommended)

BASH

pipx install .
mrma --version

dev

BASH

python3 -m venv .venv
source .venv/bin/activate
pip install -e .
mrma --version

Note:If your system CA store is broken or you’re testing lab/self-signed certs, use --insecure.

Quick start

1) Baseline fingerprint

BASH

mrma run --url https://example.com --follow-redirects

2) Find the biggest response deltas (safe mutations)

BASH

mrma impact --url https://example.com --follow-redirects --top-deltas 10

3) Compare baseline vs a single mutation (diff)

BASH

mrma diff --url https://example.com --follow-redirects --set-header "X-Test: 1"

4) Minimal required header set (delta debugging)

BASH

mrma discover --url https://example.com --follow-redirects --print-minimal-request

5) Minimal header removals that cause a change (ddmin)

BASH

mrma isolate-remove --url https://example.com --follow-redirects \
  --pack-file remove_headers.txt --preset dynamic --delay 0.2

Why this is different

Most tooling stops at: status code, length, or manual diffing.

mrma adds:

Preset-aware normalization (default, dynamic, nextjs, api-json)
Noise controls: --ignore-header, --ignore-body-regex
Stability measurement: run --repeat (great for dynamic targets)
Trust-boundary profiles:
- profile proxy-trust (forwarded/proxy headers)
- profile host-routing (host-related routing headers)
One-command reporting:
- mrma report → mrma_report.json + mrma_report.md Operational polish:
- rate limiting + retries (--rps, --retries)

Curated packs

List packs:

BASH

mrma pack list

Proxy trust pack (extended):

BASH

mrma impact --url https://example.com --follow-redirects \
  --pack proxy --depth extended --ip-set extended --top-deltas 15 --delay 0.2

Raw request mode (exact reproduction)

Replay a raw HTTP request file:

BASH

mrma run -r req.txt -u https://example.com --follow-redirects

Discover minimal request from a raw request:

BASH

mrma discover -r req.txt -u https://example.com --follow-redirects --print-minimal-request

Ignore rules (reduce noise)

Ignore volatile headers:

BASH

mrma diff --url https://example.com --follow-redirects --set-header "X-Test: 1" \
  --ignore-header set-cookie --ignore-header date --ignore-header etag

Ignore noisy dynamic content using regex:

BASH

mrma diff --url https://example.com --follow-redirects --set-header "X-Test: 1" \
  --ignore-body-regex '"nonce"\s*:\s*"[A-Za-z0-9\-_]+"' \
  --ignore-body-regex '"requestId"\s*:\s*"[A-Za-z0-9\-_]+"'

Reporting

Generate a compact report:

BASH

mrma report --url https://example.com --follow-redirects --top-deltas 10
ls -la mrma_report.*

Terminal-friendly Markdown viewing (optional):

BASH

sudo apt update && sudo apt install -y glow
glow -p mrma_report.md

JSON output

Most commands support --json:

BASH

mrma impact --url https://example.com --pack proxy --top-deltas 5 --json

Config

Global config:

~/.config/mrma/config.toml

Local (per-project):

./mrma.toml

Show merged config:

BASH

mrma config --json

Example:

TOML

[defaults]
preset = "dynamic"
timeout = 15.0
min_similarity = 0.97
max_len_delta_ratio = 0.05
 
[impact]
delay = 0.2
ip_set = "basic"
ignore_headers = ["set-cookie", "date", "etag"]

Tip: disable config for a single run:

BASH

mrma impact --url https://example.com --no-config

Safety and legal

Use only on targets you are authorized to test.
These mutations are designed to be low-risk by default, but responsibility is yours.