---
id: pyasn1
version: "0.6.4"
license: BSD-2-Clause
license_treatment: permissive
maintenance: active
---

# pyasn1 — Pure-Python implementation of ASN.1 types and DER/BER/CER codecs (X.208)

License: permissive · Maintenance: active · Popularity: top 100 on PyPI

## Install

pip install pyasn1
uv add pyasn1
poetry add pyasn1

## Description

ASN.1 library for Python
------------------------
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This is a free and open source implementation of ASN.1 types and codecs
as a Python package. It has been first written to support particular
protocol (SNMP) but then generalized to be suitable for a wide range
of protocols based on
[ASN.1 specification](https://www.itu.int/rec/dologin_pub.asp?lang=e&id=T-REC-X.208-198811-W!!PDF-E&type=items).

**NOTE:** The package is now maintained by *Christian Heimes* and
*Simon Pichugin* in project https://github.com/pyasn1/pyasn1.

Features
--------

* Generic implementation of ASN.1...

## AI interpretation — verify before relying

pyasn1 is a pure-Python implementation of ASN.1 types and codecs (BER, DER, CER) for encoding and decoding structured data used in network protocols and file formats.

Verdict: pyasn1 is a stable, actively maintained library with zero known vulnerabilities and low install friction. It is well-suited for applications requiring ASN.1 serialization across network protocols and file formats, with broad Python version support (3.8–3.14) and permissive licensing.

[View on SkillFed](https://skillfed.io/packages/pyasn1) · [View on PyPI](https://pypi.org/project/pyasn1/)