---
title: "mlab-tests-suite-sha-helper — Mova code model"
description: "Mova code model of mlab/tests/suite.rs: components with their labels, obernants and the model text."
url: "https://groupants.elamur.ai/free/en/mova/mlab/tests/suite.rs.groupant/sha-helper.groupant/"
---
Elamur: [Mova](https://md.mova.elamur.ai/free/en/) · [Dictionary](https://md.dictionary.elamur.ai/free/en/) · [Research](https://md.research.elamur.ai/free/en/) · **Groupants**

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# mlab-tests-suite-sha-helper

The groupant beside mlab/tests/suite.rs in the Mova repository: what the code computes, what it never does, how to go back from its outputs, its invariants, cost and checks.

## Facts

- **kind:** groupant_fragment
- **status:** partial source bound model
- **source:** [`mlab/tests/suite.rs`](https://github.com/ElamurAI/mova-free/blob/main/mlab/tests/suite.rs)
- **source SHA-256:** `44bf1111361f38af…`
- **covers:** Local SHA compression helper and abc self-check only. (bytes 647–3277)
- **part of:** [mlab-tests-suite](https://md.groupants.elamur.ai/free/en/mova/mlab/tests/suite.rs.groupant/)
- **repository folder:** [`mlab/tests/suite.rs.groupant/sha-helper.groupant`](https://github.com/ElamurAI/mova-free/tree/main/mlab/tests/suite.rs.groupant/sha-helper.groupant)
- **repository commit:** `855da7bd4a7b`

> **Implementation material.** A Mova code model describes this code at one source revision: partial models, finite checks and their stated scope. It is not a reviewed general exposition, and its labels are shown as written, never raised.

## Components

| component | label | where |
|---|---|---|
| **approximant** | partial | [approximant](#approximant) |
| **ast** | partial | `../syntax.json` |
| **cost** | symbolic source derived | [invariant](#invariant) |
| **descriptant** | present | [descriptant](#descriptant) |
| **invariant** | partial | [invariant](#invariant) |
| **tests** | executed bounded checks | [tests](#tests) |

## Obernants

The typed relations around the forward model: the behaviour complement (what the code never does), the reverse reconstruction (every input compatible with an output) and specialised views.

| id | type | label | where |
|---|---|---|---|
| `behavior_complement` | behavior_complement | partial source derived model | [behavior_complement](#behavior-complement) |
| `reverse_reconstruction` | reverse_reconstruction | partial source derived model | [reverse_reconstruction](#reverse-reconstruction) |
| `padding` | padding | partial source derived model | [padding](#padding) |
| `word_schedule` | word_schedule | partial source derived model | [word_schedule](#word-schedule) |
| `compression` | compression | partial source derived model | [compression](#compression) |
| `evidence` | evidence | partial source derived model | [evidence](#evidence) |

## Model text


### descriptant

#### mlab-tests-suite-sha-helper

Local SHA compression helper and abc self-check only.

##### Epoch 2026-10-31

Half-open source bytes [647,3277); bound by parent source hash and scoped byte hash. Model covers only this fragment; parent composition explains joins.

### approximant

#### Scoped forward relation

Pad message, schedule words, perform 64 rounds/block with wrapping add, hex encode8 words; self-check abc known digest.

##### Domain and gap

Source-generated states within resource limits. Categorical relation has no executable percent surrogate.

### invariant

#### Scoped invariant

Append0x80 then zero until56 mod64 then 64-bit length.

##### Cost

O(B) compression and padded input copy, fixed64-word schedule; u32 arithmetic wraps intentionally and giant bitlength conversion remains unsupported.

### models

## Scoped typed relations

### behavior_complement

abc known digest excludes any changed output nibble for that input; this finite check does not exclude collisions or failures on untested messages.

### reverse_reconstruction

Digest collision/preimage ambiguity is not resolved by one known vector; output length is64 hex characters.

### padding

Append0x80 then zero until56 mod64 then 64-bit length.

### word_schedule

Words16..63 use rotates7/18 and17/19 with wrapping sums.

### compression

Eight working words fold into hash with wrapping addition.

### evidence

Only abc vector selected; not frozen-data hashes.


### tests

#### Evidence scope

Parent selected tests: sha256_self_check, parse_error_runs_nothing, wave30_synthetic_suite_boundaries. This fragment shares parent syntax and finite checks; no separate test count or complete fragment coverage claim. Assertion-control association and unexecuted paths are in parent tests.md and source-test-map.json.