policy.rs

`crates/veilvoice-policy/src/policy.rs`

veilvoice-policy · 984 lines · read the source here · or on GitHub

The policy itself: what can be required, and what requiring it does.

Every requirement tightens, and there is nowhere to write one that does not

Requirement has five variants and all five move VeilVoice in the same direction. There is no AllowPlaintext, no MaximumIntensity, no SkipMetadataCleaning. That is not an oversight to be filled in later; it is the property the whole crate rests on, and Posture::is_at_least_as_strict_as exists so a test can hold it.

Anybody adding a variant should read crate's documentation first. A loosening variant does not merely add a feature: it removes the reason the plain file can be read without a passphrase.

Format

Text, one requirement per line, for the same reason the tamper manifest is text: the point of the file is to be readable by the person it constrains.

VEILPOLICY1
note  Set by the IT department. Ask before changing.
require  encrypt-recordings
require  clean-metadata
require  minimum-intensity  80

The floor is a whole number of hundredths, not a decimal. A policy has to compare equal to its own sealed copy, and a value that reads back as 0.7999999 would make crate::verify report Differs for ever.

An unknown require keyword is an error, not a line to skip. A policy written by a newer build says something this one cannot honour, and quietly honouring the rest would leave the machine less restricted than the person who wrote it believes. Refusing says so.

In plain words

A way to say "these settings must always be on", so that they cannot be turned off later by accident.

Everything here only ever tightens. There is deliberately no way to write a rule that makes VeilVoice do less, because a settings file that could weaken the program would be the first thing worth attacking.

If a rule and a control disagree, the rule wins and the window shows you the value that will actually be used, rather than one that quietly changes when you press the button.

WHAT THIS FILE CONTAINS

984 lines defining 25 functions (23 public), 4 types and 3 constants. Everything below is read out of the source, so it cannot disagree with the code.

The types it owns.

enum Requirement line 69 · One thing a policy can insist on.
struct Posture line 137 · The settings a policy can reach, as a front end holds them.
struct Policy line 194 · A set of requirements, and an optional note from whoever wrote them.
enum Verification line 473 · What is known about the seal on a policy.

What happens when it runs. These are the ways in: public, and nothing else in this file calls them, so they are what an outside caller reaches first.

Requirement::keyword line 88 · The keyword this is written as.
Requirement::describe line 103 · What this means, in the words a front end should show beside the control it has taken away.
Posture::most_permissive line 169 · The most permissive arrangement the controls can reach.
Posture::is_at_least_as_strict_as line 183 · Whether self is at least as strict as other in every dimension.
Policy::require line 209 · Add a requirement.
Policy::with_note line 226 · Set the note shown beside every control the policy has fixed.
Policy::note line 243 · The note, if there is one.
Policy::is_empty line 248 · Whether anything at all is required.
Policy::len line 253 · How many requirements there are.
Policy::requirements line 258 · The requirements, in a stable order.
Policy::constrain line 283 · Apply the policy to a posture.
reaches minimum_intensity, requires
Policy::save line 415 · Write the plain policy into dir, and the sealed copy beside it.
reaches seal, to_text
Verification::describe line 493 · One line for a front end.
Verification::wants_attention line 518 · Whether this is a state somebody should look at.
verify line 530 · Check the plain policy in dir against its sealed copy.
reaches load, open_sealed, parse, new, requirement_from, default

WHAT CALLS WHAT

The functions this file defines, and the calls between them. An edge means the callee's name appears, called, inside the caller's body. This is a syntactic reading, not a type-resolved one. 22 of 24 functions are drawn; the diagram is bounded at 22 so it stays readable.

The same graph as Mermaid source

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flowchart TD
    n_keyword(["Requirement::keyword<br/>line 88"])
    n_describe(["Requirement::describe<br/>line 103"])
    n_default["Posture::default<br/>line 152"]
    n_most_permissive(["Posture::most_permissive<br/>line 169"])
    n_is_at_least_as_strict_as(["Posture::<br/>is_at_least_as_strict_as<br/>line 183"])
    n_new["Policy::new<br/>line 204"]
    n_require(["Policy::require<br/>line 209"])
    n_with_note(["Policy::with_note<br/>line 226"])
    n_note(["Policy::note<br/>line 243"])
    n_is_empty(["Policy::is_empty<br/>line 248"])
    n_len(["Policy::len<br/>line 253"])
    n_requires["Policy::requires<br/>line 263"]
    n_minimum_intensity["Policy::minimum_intensity<br/>line 268"]
    n_constrain(["Policy::constrain<br/>line 283"])
    n_to_text["Policy::to_text<br/>line 304"]
    n_parse["Policy::parse<br/>line 330"]
    n_seal["Policy::seal<br/>line 376"]
    n_open_sealed["Policy::open_sealed<br/>line 398"]
    n_save(["Policy::save<br/>line 415"])
    n_load["Policy::load<br/>line 432"]
    n_requirement_from["requirement_from<br/>line 441"]
    n_verify(["verify<br/>line 530"])
    n_constrain --> n_minimum_intensity
    n_constrain --> n_requires
    n_load --> n_parse
    n_new --> n_default
    n_open_sealed --> n_parse
    n_parse --> n_new
    n_parse --> n_requirement_from
    n_save --> n_seal
    n_save --> n_to_text
    n_seal --> n_to_text
    n_verify --> n_load
    n_verify --> n_open_sealed
    click n_keyword href "https://github.com/tilas01/veilvoice/blob/main/crates/veilvoice-policy/src/policy.rs#L88" "open the source"
    click n_describe href "https://github.com/tilas01/veilvoice/blob/main/crates/veilvoice-policy/src/policy.rs#L103" "open the source"
    click n_default href "https://github.com/tilas01/veilvoice/blob/main/crates/veilvoice-policy/src/policy.rs#L152" "open the source"
    click n_most_permissive href "https://github.com/tilas01/veilvoice/blob/main/crates/veilvoice-policy/src/policy.rs#L169" "open the source"
    click n_is_at_least_as_strict_as href "https://github.com/tilas01/veilvoice/blob/main/crates/veilvoice-policy/src/policy.rs#L183" "open the source"
    click n_new href "https://github.com/tilas01/veilvoice/blob/main/crates/veilvoice-policy/src/policy.rs#L204" "open the source"
    click n_require href "https://github.com/tilas01/veilvoice/blob/main/crates/veilvoice-policy/src/policy.rs#L209" "open the source"
    click n_with_note href "https://github.com/tilas01/veilvoice/blob/main/crates/veilvoice-policy/src/policy.rs#L226" "open the source"
    click n_note href "https://github.com/tilas01/veilvoice/blob/main/crates/veilvoice-policy/src/policy.rs#L243" "open the source"
    click n_is_empty href "https://github.com/tilas01/veilvoice/blob/main/crates/veilvoice-policy/src/policy.rs#L248" "open the source"
    click n_len href "https://github.com/tilas01/veilvoice/blob/main/crates/veilvoice-policy/src/policy.rs#L253" "open the source"
    click n_requires href "https://github.com/tilas01/veilvoice/blob/main/crates/veilvoice-policy/src/policy.rs#L263" "open the source"
    click n_minimum_intensity href "https://github.com/tilas01/veilvoice/blob/main/crates/veilvoice-policy/src/policy.rs#L268" "open the source"
    click n_constrain href "https://github.com/tilas01/veilvoice/blob/main/crates/veilvoice-policy/src/policy.rs#L283" "open the source"
    click n_to_text href "https://github.com/tilas01/veilvoice/blob/main/crates/veilvoice-policy/src/policy.rs#L304" "open the source"
    click n_parse href "https://github.com/tilas01/veilvoice/blob/main/crates/veilvoice-policy/src/policy.rs#L330" "open the source"
    click n_seal href "https://github.com/tilas01/veilvoice/blob/main/crates/veilvoice-policy/src/policy.rs#L376" "open the source"
    click n_open_sealed href "https://github.com/tilas01/veilvoice/blob/main/crates/veilvoice-policy/src/policy.rs#L398" "open the source"
    click n_save href "https://github.com/tilas01/veilvoice/blob/main/crates/veilvoice-policy/src/policy.rs#L415" "open the source"
    click n_load href "https://github.com/tilas01/veilvoice/blob/main/crates/veilvoice-policy/src/policy.rs#L432" "open the source"
    click n_requirement_from href "https://github.com/tilas01/veilvoice/blob/main/crates/veilvoice-policy/src/policy.rs#L441" "open the source"
    click n_verify href "https://github.com/tilas01/veilvoice/blob/main/crates/veilvoice-policy/src/policy.rs#L530" "open the source"
    classDef entry fill:#1f2335,stroke:#7aa2f7,color:#c0caf5
    class n_keyword,n_describe,n_most_permissive,n_is_at_least_as_strict_as,n_require,n_with_note,n_note,n_is_empty,n_len,n_constrain,n_save,n_verify entry
    classDef api fill:#1f2335,stroke:#7dcfff,color:#c0caf5
    class n_new,n_requires,n_minimum_intensity,n_to_text,n_parse,n_seal,n_open_sealed,n_load api
    classDef helper fill:#1f2335,stroke:#bb9af7,color:#c0caf5
    class n_default,n_requirement_from helper

This site loads no third-party script, so it cannot run Mermaid; the diagram above is the same nodes and edges drawn by the generator instead. GitHub renders the source below directly.

ITEMS

Item	Line	Documentation
`MAGIC` _const	56	Magic first line.
`PLAIN_FILE` _{pub const}	59	The plain policy, read at every launch and needing no passphrase.
`SEALED_FILE` _{pub const}	63	The same policy sealed under a passphrase, for proving the plain one is what was written.
`Requirement` _{pub enum}	69	One thing a policy can insist on.
`Requirement::keyword` _{pub fn}	88	The keyword this is written as.
`Requirement::describe` _{pub fn}	103	What this means, in the words a front end should show beside the control it has taken away.
`Posture` _{pub struct}	137	The settings a policy can reach, as a front end holds them.
`Posture::default` _fn	152	VeilVoice's own defaults, which are the strict ones.
`Posture::most_permissive` _{pub fn}	169	The most permissive arrangement the controls can reach.
`Posture::is_at_least_as_strict_as` _{pub fn}	183	Whether self is at least as strict as other in every dimension.
`Policy` _{pub struct}	194	A set of requirements, and an optional note from whoever wrote them.
`Policy::new` _{pub fn}	204	A policy that requires nothing.
`Policy::require` _{pub fn}	209	Add a requirement.
`Policy::with_note` _{pub fn}	226	Set the note shown beside every control the policy has fixed.
`Policy::note` _{pub fn}	243	The note, if there is one.
`Policy::is_empty` _{pub fn}	248	Whether anything at all is required.
`Policy::len` _{pub fn}	253	How many requirements there are.
`Policy::requirements` _{pub fn}	258	The requirements, in a stable order.
`Policy::requires` _{pub fn}	263	Whether a particular requirement is in force.
`Policy::minimum_intensity` _{pub fn}	268	The intensity floor, or 0.0 when none is set.
`Policy::constrain` _{pub fn}	283	Apply the policy to a posture.
`Policy::to_text` _{pub fn}	304	Serialise to the text format described at the top of this module.
`Policy::parse` _{pub fn}	330	Parse the text format.
`Policy::seal` _{pub fn}	376	Seal the policy under a passphrase.
`Policy::open_sealed` _{pub fn}	398	Open a policy sealed by Policy::seal.
`Policy::save` _{pub fn}	415	Write the plain policy into dir, and the sealed copy beside it.
`Policy::load` _{pub fn}	432	Read the plain policy from dir.
`requirement_from` _fn	441
`Verification` _{pub enum}	473	What is known about the seal on a policy.
`Verification::describe` _{pub fn}	493	One line for a front end.
`Verification::wants_attention` _{pub fn}	518	Whether this is a state somebody should look at.
`verify` _{pub fn}	530	Check the plain policy in dir against its sealed copy.