Examples

Every example is a complete script. Copy it into your project, or press Run to execute it in your browser with the current version of asn1js.

Basics

• Decode BER and DER: turn bytes into ASN.1 objects and handle decoding errors.
• Encode to DER: build structures and get their bytes or hex.
• Convert to JavaScript values: integers, BigInt, OIDs, strings, and dates.
• Explicit and implicit tags: encode and decode context-specific tags such as [0].

Schemas

• Validate against a schema: check structure and read fields by name.
• CHOICE and SEQUENCE OF: alternatives and lists with Choice and Repeated.
• Structures inside an OCTET STRING: validate encoded data nested in another value.

Real-world data

• Read an X.509 certificate: serial number, issuer, subject, and validity from a PEM file.
• Read a public key: algorithm, curve, and key bytes from a SubjectPublicKeyInfo.
• Parse untrusted input: limit nesting, node count, and content length.