data-representation SKILL.md skillA
data-representation from dannyan/secguard-clang is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add dannyan/secguard-clang/data-representation@git:20261017.a78401fPins git:20261017.a78401f in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- dannyan/secguard-clang
- Path
extension/shared/skills/data-representation/SKILL.md- Versions recorded
- 3
- Latest version
- git:20261017.a78401f, committed Oct 17, 2026
- First version recorded
- Sep 20, 2026
- Size
- 5,981 bytes
- Repository stars
- 25
- License
- Apache-2.0
Classify data-representation evidence — a generic/opaque-pointer consumer misinterprets the object representation the API call established. Default-maps to CWE-843.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
## Opaque/Generic Pointer Representation Analysis (CWE-843) `contract_kind: implicit` — a generic/opaque-pointer API erases an object's static type to `void *`; the actual object representation is a contract established at the **call site** (for `qsort`/`bsearch`: `base` + `size`), which the consumer (comparator/callback) must interpret consistently. ### Core Principle Judge the consumer **together with its call site, never alone.** A `void *` cast in isolation proves nothing: ```c const char *s = *(const char **)a; ``` is correct when the caller sorts `char *items[]` (elements are pointers) and wrong when the caller sorts `char items[]` (elements are scalars). Confirm the actual element representation at the API call site before confirming a mismatch. This pair property is what separates the pattern from a local cast rule. ### Concept vs Phase-1 coverage - **Concept (the pattern)**: opaque/generic pointer → API establishes an object representation → consumer interprets the opaque pointer → actual representation ≠ interpreted representation → contract violation. This one skill owns the concept; future `callback(void *)`, opaque context, container, …
Read the whole file at its exact version.
How to install
mdr add dannyan/secguard-clang/data-representation@sha256:2daf747a262068d7The line at the top of this page pins the label git:20261017.a78401f, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_rwymki45keytxfx2)
1 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 3 versions of this file, between Sep 20, 2026 and Oct 17, 2026, about one every 14 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20261017.a78401f latest | 2026-10-17 | a78401f | 5,981 B | A | view · diff |
| git:20261016.fb3b156 | 2026-10-16 | fb3b156 | 5,603 B | A | view · diff |
| git:20260920.cbf3e06 | 2026-09-20 | cbf3e06 | 5,589 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (5981 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
dannyan/secguard-clang · 25 stars · license Apache-2.0 · pushed 2026-10-22 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_rwymki45keytxfx2 GET https://markdownregistry.com/api/v1/resolve?ref=dannyan/secguard-clang/data-representation GET https://markdownregistry.com/api/v1/blob/2daf747a262068d7142078904b1102ee962bf96d07fbe797e64fcf2878bc068c
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.