Python库 | aiodnsresolver-0.0.38.tar.gz

# aiodnsresolver [](https://circleci.com/gh/michalc/aiodnsresolver) [](https://codeclimate.com/github/michalc/aiodnsresolver/test_coverage) Asyncio Python DNS resolver. Pure Python, with no dependencies other than the standard library, threads are not used, and all code is in a single module. The nameservers to query are taken from `/etc/resolve.conf`. Based on https://github.com/gera2ld/async_dns. ## Installation ```bash pip install aiodnsresolver ``` ## Usage ```python from aiodnsresolver import Resolver, TYPES resolve = Resolver() ip_address = await resolve('www.google.com', TYPES.A) ``` The IP address returned is an instance of [IPv4Address](https://docs.python.org/3/library/ipaddress.html#ipaddress.IPv4Address) or [IPv6Address](https://docs.python.org/3/library/ipaddress.html#ipaddress.IPv6Address). Both support conversion to their usual string form by passing them to `str`. ## Security considerations To migitate spoofing, several techniques are used. - Each query is given a random ID, which is checked against any response. - Each domain name is encoded with [0x20-bit encoding](https://astrolavos.gatech.edu/articles/increased_dns_resistance.pdf), which is checked against any response. - A new socket, and so a new random local port, is used for each query. ## Scope The scope of this project is deliberately restricted to operations that are used to resolve A or AAAA records: to resolve a domain name to one of its IP addresses, and have similar responsibilities to `gethostbyname`. Some limited extra behaviour is present/may be added, but great care is taken to prevent scope creep, especially to not add complexity that isn't required to resolve A or AAAA records. - UDP queries are made, but not TCP. DNS servers must support UDP, and it's impossible for a single A and AAAA record to not fit into the maximum size of a UDP DNS response, 512 bytes. There may be other data that the DNS server would return in TCP connections, but this isn't required to resolve a domain name to a single IP address. - CNAME records are followed transparently. - Responses are cached, adhering to their TTL. - The resolver is a _stub_ resolver: it delegates the responsibility of recursion to the nameserver(s) it queries. In the vast majority of envisioned use cases this is acceptable, since the nameservers in `/etc/resolve.conf` will be recursive.