Dig into SPF records

run.py

import pydig
from dataclasses import dataclass

def get_spf_record(domain: str) -> str:
    txts = pydig.query(domain, 'TXT')
    result = list(filter(lambda x: "v=spf" in x, txts))
    if len(result) == 0:
        raise Exception(f"SPF not found for {domain}")
    elif len(result) > 1:
        raise Exception(f"too many SPF found for {domain}")
    return result[0]

def get_included_domains(spf_record: str) -> list[str]:
    return list(
        map(lambda x: x[8:], 
            filter(lambda x: x.startswith("include:"), spf_record.split(" "))
        )
    )


@dataclass
class IncludedDomain:
    indent: int
    domain: str

queries_to_do = []

queries_to_do.append(IncludedDomain(0, "kiwix.org"))

while len(queries_to_do) > 0:
    included_domain = queries_to_do.pop()

    spf_record = get_spf_record(included_domain.domain)
    sub_domains = get_included_domains(spf_record)
    records = spf_record.split(" ")
    spaces = ["  " for x in range(included_domain.indent)]
    text = spaces + [f"{included_domain.domain}: {len(records)} instructions, among which {len(sub_domains)} includes"]
    print("".join(text))
    for sub_domain in sub_domains:
        queries_to_do.append(IncludedDomain(included_domain.indent + 1, sub_domain))
    # print(get_included_domains(get_spf_record(included_domain.domain)))