{"id":426,"library":"asn1crypto","title":"asn1crypto","description":"A fast, pure Python library for parsing and serializing ASN.1 structures, including private keys, public keys, certificates, and various PKCS standards. Current version: 1.5.1. Release cadence: irregular, with the latest release on March 15, 2022. ([pypi.org](https://pypi.org/project/asn1crypto/?utm_source=openai))","status":"active","version":"1.5.1","language":"python","source_language":"en","source_url":"https://github.com/wbond/asn1crypto","tags":["ASN.1","cryptography","X.509","PKCS","Python"],"install":[{"cmd":"pip install asn1crypto","lang":"bash","label":"Install asn1crypto"}],"dependencies":[],"imports":[{"note":"Ensure correct import path to access X.509 certificate parsing and serialization.","symbol":"x509","correct":"from asn1crypto import x509"}],"quickstart":{"code":"from asn1crypto import x509\n\n# Load a certificate from a file\nwith open('certificate.pem', 'rb') as f:\n    cert_data = f.read()\n\n# Parse the certificate\ncert = x509.Certificate.load(cert_data)\n\n# Access certificate details\nprint(cert.subject.native)  # Print the subject of the certificate\nprint(cert.serial_number)   # Print the serial number of the certificate","lang":"python","description":"A basic example demonstrating how to load, parse, and access details of an X.509 certificate using asn1crypto."},"warnings":[{"fix":"Upgrade to the latest version of asn1crypto.","message":"The 'x509' module was introduced in version 0.22.0. Ensure your version is up-to-date to use this module.","severity":"breaking","affected_versions":"0.22.0 and later"},{"fix":"Convert PEM to DER format before parsing or use appropriate methods to handle PEM format.","message":"When parsing certificates, ensure the input data is in DER format. PEM format requires base64 decoding before parsing.","severity":"gotcha","affected_versions":"All versions"},{"fix":"Ensure the 'certificate.pem' file is present in the working directory or provide the correct absolute/relative path to the file.","message":"The script failed because 'certificate.pem' was not found. Ensure the certificate file exists in the expected path.","severity":"breaking","affected_versions":"All versions"},{"fix":"Provide the 'certificate.pem' file in the script's execution directory or update the file path in the script to point to the correct location of the certificate file.","message":"The script failed because 'certificate.pem' was not found. Ensure the certificate file exists in the expected location and has the correct permissions.","severity":"breaking","affected_versions":"All versions"}],"env_vars":null,"last_verified":"2026-05-12T13:43:49.918Z","next_check":"2026-06-26T00:00:00.000Z","problems":[{"fix":"Install the package using pip: 'pip install asn1crypto'.","cause":"The 'asn1crypto' package is not installed in the Python environment.","error":"ModuleNotFoundError: No module named 'asn1crypto'"},{"fix":"Upgrade to the latest version of 'asn1crypto' using pip: 'pip install --upgrade asn1crypto'.","cause":"The 'core' module is not available in the 'asn1crypto' package, possibly due to an outdated version.","error":"ImportError: cannot import name 'core' from 'asn1crypto'"},{"fix":"Ensure the correct import statement: 'from asn1crypto import x509'.","cause":"The 'x509' module is not present in the 'asn1crypto' package, likely due to an incorrect import statement.","error":"AttributeError: module 'asn1crypto' has no attribute 'x509'"},{"fix":"Check if the parsing operation returned 'None' and handle the error accordingly.","cause":"Attempting to access an element of a 'None' object, possibly due to a failed parsing operation.","error":"TypeError: 'NoneType' object is not subscriptable"},{"fix":"Verify the input data for correctness and ensure it conforms to the expected ASN.1 structure.","cause":"The input data contains an invalid ASN.1 tag, leading to a parsing error.","error":"ValueError: Invalid ASN.1 tag"}],"ecosystem":"pypi","meta_description":null,"install_score":100,"install_tag":"verified","quickstart_score":0,"quickstart_tag":"stale","pypi_latest":null,"install_checks":{"last_tested":"2026-05-12","tag":"verified","tag_description":"installs cleanly on critical runtimes, fast import, recently tested","results":[{"runtime":"python:3.10-alpine","python_version":"3.10","os_libc":"alpine (musl)","variant":"default","exit_code":0,"wheel_type":null,"failure_reason":null,"install_time_s":null,"import_time_s":0.07,"mem_mb":3.4,"disk_size":"18.7M"},{"runtime":"python:3.10-slim","python_version":"3.10","os_libc":"slim (glibc)","variant":"default","exit_code":0,"wheel_type":null,"failure_reason":null,"install_time_s":null,"import_time_s":0.05,"mem_mb":3.4,"disk_size":"19M"},{"runtime":"python:3.11-alpine","python_version":"3.11","os_libc":"alpine (musl)","variant":"default","exit_code":0,"wheel_type":null,"failure_reason":null,"install_time_s":null,"import_time_s":0.15,"mem_mb":3.7,"disk_size":"20.7M"},{"runtime":"python:3.11-slim","python_version":"3.11","os_libc":"slim (glibc)","variant":"default","exit_code":0,"wheel_type":null,"failure_reason":null,"install_time_s":null,"import_time_s":0.12,"mem_mb":3.7,"disk_size":"21M"},{"runtime":"python:3.12-alpine","python_version":"3.12","os_libc":"alpine (musl)","variant":"default","exit_code":0,"wheel_type":null,"failure_reason":null,"install_time_s":null,"import_time_s":0.1,"mem_mb":3.7,"disk_size":"12.6M"},{"runtime":"python:3.12-slim","python_version":"3.12","os_libc":"slim (glibc)","variant":"default","exit_code":0,"wheel_type":null,"failure_reason":null,"install_time_s":null,"import_time_s":0.11,"mem_mb":3.7,"disk_size":"13M"},{"runtime":"python:3.13-alpine","python_version":"3.13","os_libc":"alpine (musl)","variant":"default","exit_code":0,"wheel_type":null,"failure_reason":null,"install_time_s":null,"import_time_s":0.1,"mem_mb":4,"disk_size":"12.2M"},{"runtime":"python:3.13-slim","python_version":"3.13","os_libc":"slim (glibc)","variant":"default","exit_code":0,"wheel_type":null,"failure_reason":null,"install_time_s":null,"import_time_s":0.1,"mem_mb":4,"disk_size":"13M"},{"runtime":"python:3.9-alpine","python_version":"3.9","os_libc":"alpine (musl)","variant":"default","exit_code":0,"wheel_type":null,"failure_reason":null,"install_time_s":null,"import_time_s":0.07,"mem_mb":3.4,"disk_size":"18.2M"},{"runtime":"python:3.9-slim","python_version":"3.9","os_libc":"slim (glibc)","variant":"default","exit_code":0,"wheel_type":null,"failure_reason":null,"install_time_s":null,"import_time_s":0.06,"mem_mb":3.4,"disk_size":"19M"}]},"quickstart_checks":{"last_tested":"2026-04-23","tag":"stale","tag_description":"widespread failures or data too old to trust","results":[{"runtime":"python:3.10-alpine","exit_code":1},{"runtime":"python:3.10-slim","exit_code":1},{"runtime":"python:3.11-alpine","exit_code":1},{"runtime":"python:3.11-slim","exit_code":1},{"runtime":"python:3.12-alpine","exit_code":1},{"runtime":"python:3.12-slim","exit_code":1},{"runtime":"python:3.13-alpine","exit_code":1},{"runtime":"python:3.13-slim","exit_code":1},{"runtime":"python:3.9-alpine","exit_code":1},{"runtime":"python:3.9-slim","exit_code":1}]}}