Stdlib module crypto/keyderivation.vitl

Overview

`crypto/keyderivation.vitl` is a public stdlib surface inside the `crypto` family. It should be read as one focused slice of the broader family responsibility: Hashing, HMAC, randomness, key derivation, symmetric primitives, and asymmetric primitives.

Purpose

This file should be chosen because of responsibility, not because its name “sounds close enough”. Inside the crypto family, it carries one focused part of the contract and keeps that responsibility separate from neighboring concerns.

• A package manifest can be serialized first, then hashed, then optionally signed.
• A token flow can derive a key in one boundary and use it in another without mixing concerns.

Taxonomy

Think of this page as a generated encyclopedia entry rather than a hand-written tutorial. The goal is to show what kind of module this is, how dense it is, and what reading strategy makes sense before depending on it.

• Compact procedure surface: this file is small enough to read end-to-end before depending on it.
• Owns domain vocabulary: the module declares data shapes in addition to executable helpers, so its types are part of the contract.
• Minimal top-level dependencies: the module reads as mostly self-contained from its opening declarations.
• Explicit export surface: the file ends with visible export declarations instead of relying only on implicit namespace discovery.

Implementation profile

This profile is inferred directly from the source text. It does not replace reading the file, but it tells you quickly whether the module is mostly declarative, loop-heavy, branch-heavy, or organized around many small exits.

Top-level API inventory

Imported surfaces

This file does not advertise a top-level `use` surface in its opening declarations. That often means it is either self-contained or an aggregation layer.

Position in family

This file is module 6 of 9 in the crypto family when ordered by path. By procedure count it ranks 9, and by line count it ranks 6. Those ranks are useful as rough signals of breadth, not as quality judgments.

Declaration map

The declaration map turns raw source into a scan-friendly catalog. It is useful when the file is large enough that a reader wants to orient by kinds of surfaces first.

The table is exhaustive for top-level declarations of the selected kinds. This file declares 9 matching surfaces.

Representative signatures

These signatures are shown in source order so the page keeps the feel of a reference manual, not just a keyword cloud.

• form KeyDerivationManifest { (line 7)
• proc pbkdf2(password: string, salt: string, iterations: i32, length: i32) -> string { (line 14)
• proc bcrypt_hash(password: string, rounds: i32) -> string { (line 18)
• proc bcrypt_verify(password: string, hash: string) -> int { (line 22)
• proc keyderivation_version() -> string { (line 26)
• proc keyderivation_ready() -> bool { (line 30)
• proc keyderivation_manifest() -> KeyDerivationManifest { (line 34)
• proc keyderivation_selftest() -> bool { (line 42)

How to use this module

Start by reading the file as an ownership boundary. Ask three questions: what enters this module, what stable types or procedures it exports, and what adjacent module should stay outside of it.

1. Read space and top-level imports first so the ownership boundary of crypto/keyderivation.vitl is explicit.
2. Read declared forms and picks before algorithms so the data vocabulary is stable in your head.
3. Traverse procedures in source order; the early helpers usually explain the naming and numeric conventions used later.
4. Use the source landmarks section below as a table of contents when the file is large.
5. Only after that compare neighbor modules, because the right boundary choice matters more than memorizing one helper name.

User example

This example is generated from the actual stdlib module surface. Its job is not to be the smallest snippet possible; its job is to show a realistic consumer-shaped file that exercises the module and mirrors the language keywords the module itself relies on.

space demo/crypto_keyderivation
form UserReport {
  label: string,
  ready: bool
}
proc run_example() -> UserReport {
  let result = pbkdf2("sample", "sample", 1, 1)
  let ready: bool = keyderivation_ready()
  let stable: bool = ready and true
    give UserReport { label: "ok", ready: true }
}
export run_example

Keyword coverage

This table makes the “all keywords of the module” requirement auditable. It compares the detected Vitte keywords in the source file with the generated consumer example above.

The generated snippet exercises every detected Vitte keyword used by this module.

Source shape

space vitte/crypto/keyderivation
form KeyDerivationManifest {
  name: string,
  version: string,
  ready: bool
}
// Key derivation
proc pbkdf2(password: string, salt: string, iterations: i32, length: i32) -> string {
  give ""
}

The excerpt is not meant to replace the file. It exists to make the module recognizable at first glance, the same way a Wikipedia infobox helps the reader orient before reading the whole article.

Source landmarks

Large files are easier to retain when they have visible landmarks. When the source contains explicit section banners, they are surfaced here; otherwise the first major declarations are used as anchors.

• Key Derivation Module

Source organization

When a file carries its own internal chaptering, those chapters usually reveal the intended reading order better than a flat symbol list. This section reconstructs that organization from the source itself.

Complete API catalog

This catalog is the exhaustive file-level index for the module. It is intentionally closer to a generated encyclopedia appendix than to a tutorial summary.

Data surfaces

Procedures

Exports

Integration boundaries

Within crypto, this file should remain focused. If a future helper changes the host boundary, scheduling boundary, or data-shape boundary, it probably belongs in a neighbor module instead of being added here by convenience.

• Family responsibility: Hashing, HMAC, randomness, key derivation, symmetric primitives, and asymmetric primitives.
• Family architecture role: Use `crypto` when integrity, secrecy, or key management is the feature. This family should never be presented as generic formatting or utility code.

Composition guidance

Choose this module when

• Choose crypto/keyderivation.vitl when the main question is owned by this module rather than by transport, storage, orchestration, or user-interface code.
• A package manifest can be serialized first, then hashed, then optionally signed.
• A token flow can derive a key in one boundary and use it in another without mixing concerns.

Pause before extending it when

• Avoid extending this file when the new helper mostly changes the boundary to host I/O, runtime coordination, or foreign integration instead of staying inside crypto.
• Check nearby modules such as crypto/asymmetric.vitl, crypto/hash.vitl, crypto/hashing.vitl before adding convenience wrappers here.

Relationship table

This table keeps the page closer to a real encyclopedia entry: a module is easier to understand when compared with its nearest alternatives in the same family.

Neighbor modules

• crypto/asymmetric.vitl
• crypto/hash.vitl
• crypto/hashing.vitl
• crypto/hmac.vitl
• crypto/random.vitl
• crypto/symmetric.vitl
• crypto/utils.vitl
• crypto.vitl