poka.sh

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DER

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ASN.1 DER Preview.

At a glance
Purpose A DER-encoded ASN.1 file: the binary encoding behind X.509 certificates, keys, CRLs and other cryptographic structures.
Extensions .der
Poka parser poka-asn1
Viewer poka-tree-viewer
Depth tier Parser with a shared viewer (see Depth tiers)
Breadth tier B3 Core (see Breadth tiers)

How much Poka reads

B3 Core. Only the main content type or types are decoded (for example geometry but not materials, layers or annotations, or only one version family). The list of gaps is substantial.

Confidence: medium (the reviewer read the code). Basis: Reviewed 2026-10-26: read parsers/poka-asn1/src/main.rs (344 lines) and plugin.json. The three unit tests cover cutting strings at a character boundary; the corpus has no .der or .asn1 sample. Covers .der and .asn1. The tree walks every tag-length-value with no schema: universal types are named, small integers, booleans, OIDs (dotted), strings and times are shown, and other values as their first 16 bytes in hex. Judgement: B3: the structure is decoded generically, but nothing is interpreted, so a certificate in .der is not shown as a certificate.

What Poka does not read

  • No schema is applied: a certificate, key or CRL in DER is not decoded as one
  • OIDs are shown as dotted numbers, not named
  • Binary values (BIT STRING, OCTET STRING, large integers) show only their first 16 bytes
  • BMPString is decoded as UTF-8, not UTF-16 (judgement from the code)
  • BER indefinite lengths and high tag numbers (31 and up) are not read
  • Caps of 5,000 nodes and 200 levels

Libraries

Libraries Poka uses or has assessed for this format, with the status, licence and language the registry records.

Sources

  • parsers/poka-asn1/src/main.rs
  • parsers/poka-asn1/plugin.json