Struct SubspaceId 

pub struct SubspaceId(/* private fields */);

The type of SubspaceIds used by Willow’25.

Subspaces group Willow data within the same namespace into independent collections — entries with nonequal subspace ids cannot overwrite each other. Subspaces further play a role in access control for Willow: subspace ids are public keys of a digital signature system, and knowledge of the corresponding secret key allow you to issue write entries to a subspace, and to delegate access to other users — see the meadowcap module for more details.

That all said, you can also simply think of subspace ids as glorified [u8; 32] arrays. That perspective should be sufficient as long as you do not need to care about cryptographic details.

You will typically obtain a subspace id either by randomly generating a key pair, by cloning an existing subspace id, or by creating it from raw bytes via SubspaceId::from_bytes. See the Willow25 specification if you want to work with raw bytes — while every [u8; 32] can be converted into a SubspaceId, some of these do not correspond to canonic public key encodings and thus always fail signature verification.

use rand::rngs::OsRng;
use willow25::prelude::*;

let mut csprng = OsRng; // cryptographically secure pseudo-random number generator
let (_subspace_id, _secret) = randomly_generate_subspace(&mut csprng);

let subspace_id2 = SubspaceId::from_bytes(&[17; SUBSPACE_ID_WIDTH]);
assert_eq!(subspace_id2.as_bytes(), &[17; 32]);

Implementations

impl SubspaceId

pub fn from_bytes(bytes: &[u8; 32]) -> Self

Returns a new SubspaceId corresponding to the supplied bytes.

use willow25::prelude::*;

let subspace_id = SubspaceId::from_bytes(&[17; SUBSPACE_ID_WIDTH]);
assert_eq!(subspace_id.as_bytes(), &[17; SUBSPACE_ID_WIDTH]);

pub fn as_bytes(&self) -> &[u8; 32]

Returns a reference to the raw bytes that make up this subspace id.

use willow25::prelude::*;

let subspace_id = SubspaceId::from_bytes(&[17; SUBSPACE_ID_WIDTH]);
assert_eq!(subspace_id.as_bytes(), &[17; SUBSPACE_ID_WIDTH]);

pub fn to_bytes(&self) -> [u8; 32]

Returns the raw bytes that make up this subspace id.

use willow25::prelude::*;

let subspace_id = SubspaceId::from_bytes(&[17; SUBSPACE_ID_WIDTH]);
assert_eq!(subspace_id.to_bytes(), [17; SUBSPACE_ID_WIDTH]);

pub fn from_ed25519_verifying_key(verifying_key: VerifyingKey) -> Self

Creates a subspace id from an ed25519 verifying key.

use willow25::prelude::*;

let from_key = SubspaceId::from_ed25519_verifying_key(
    ed25519_dalek::VerifyingKey::from_bytes(&[17; 32]).unwrap(),
);
let from_bytes = SubspaceId::from_bytes(&[17; SUBSPACE_ID_WIDTH]);

assert_eq!(from_key, from_bytes);

Trait Implementations

impl AuthorisationToken<MCL, MCC, MPL, NamespaceId, SubspaceId, PayloadDigest> for AuthorisationToken

You only need this trait impl if you work with fully generic code from the willow_data_model crate.

type Ingredients = McIngredients

The type of the information you need in order to authorise an entry. For example, in Meadowcap, this would be a pair of a capability and a secret key.

type CreationError = DoesNotAuthorise

Everything that can go wrong when trying to create a new authorisation token from some Ingredients for some entry.

fn new_for_entry<E>( entry: &E, ingredients: &Self::Ingredients, ) -> Result<Self, Self::CreationError>

where E: EntrylikeExt<MCL, MCC, MPL, NamespaceId, SubspaceId, PayloadDigest> + ?Sized,

Creates an authorisation token for the given entry, if possible.

fn does_authorise<E>(&self, entry: &E) -> bool

where E: EntrylikeExt<MCL, MCC, MPL, NamespaceId, SubspaceId, PayloadDigest> + ?Sized,

Determines whether self authorises the given entry.

impl Clone for SubspaceId

fn clone(&self) -> SubspaceId

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Coordinatelike<MCL, MCC, MPL, SubspaceId> for (Path, SubspaceId, Timestamp)

fn wdm_timestamp(&self) -> Timestamp

Returns the timestamp of self.

impl Coordinatelike<MCL, MCC, MPL, SubspaceId> for (Path, Timestamp, SubspaceId)

fn wdm_timestamp(&self) -> Timestamp

Returns the timestamp of self.

impl Coordinatelike<MCL, MCC, MPL, SubspaceId> for (SubspaceId, Path, Timestamp)

fn wdm_timestamp(&self) -> Timestamp

Returns the timestamp of self.

impl Coordinatelike<MCL, MCC, MPL, SubspaceId> for (SubspaceId, Timestamp, Path)

fn wdm_timestamp(&self) -> Timestamp

Returns the timestamp of self.

impl Coordinatelike<MCL, MCC, MPL, SubspaceId> for (Timestamp, Path, SubspaceId)

fn wdm_timestamp(&self) -> Timestamp

Returns the timestamp of self.

impl Coordinatelike<MCL, MCC, MPL, SubspaceId> for (Timestamp, SubspaceId, Path)

fn wdm_timestamp(&self) -> Timestamp

Returns the timestamp of self.

impl Coordinatelike<MCL, MCC, MPL, SubspaceId> for AuthorisedEntry

fn wdm_timestamp(&self) -> Timestamp

Returns the timestamp of self.

impl Coordinatelike<MCL, MCC, MPL, SubspaceId> for Entry

fn wdm_timestamp(&self) -> Timestamp

Returns the timestamp of self.

impl Coordinatelike<MCL, MCC, MPL, SubspaceId> for PossiblyAuthorisedEntry

fn wdm_timestamp(&self) -> Timestamp

Returns the timestamp of self.

impl Debug for SubspaceId

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Decodable for SubspaceId

type ErrorReason = Infallible

Reason why decoding can fail (beyond an unexpected end of input or a producer error).

async fn decode<P>( producer: &mut P, ) -> Result<Self, DecodeError<P::Final, P::Error, Self::ErrorReason>>

where P: BulkProducer<Item = u8> + ?Sized, Self: Sized,

Decodes the symbols produced by the given bulk producer into a Self, or yields an error if the producer does not produce a valid encoding.

impl DecodableCanonic for SubspaceId

type ErrorCanonic = Infallible

The type for reporting that the sequence of symbols to decode was not a valid canonic encoding of any value of type Self.

async fn decode_canonic<P>( producer: &mut P, ) -> Result<Self, DecodeError<P::Final, P::Error, Self::ErrorCanonic>>

where P: BulkProducer<Item = u8> + ?Sized, Self: Sized,

Decodes the symbols produced by the given bulk producer into a Self, and errors if the input encoding is not the canonical one.

impl Encodable for SubspaceId

async fn encode<C>(&self, consumer: &mut C) -> Result<(), C::Error>

where C: BulkConsumer<Item = u8> + ?Sized,

Writes an encoding of &self into the given bulk consumer.

impl EncodableKnownLength for SubspaceId

fn len_of_encoding(&self) -> usize

Computes the number of symbols of the encoding of self. A successful call to encode must feed exactly that many symbols into the bulk consumer.

impl Entrylike<MCL, MCC, MPL, NamespaceId, SubspaceId, PayloadDigest> for AuthorisedEntry

fn wdm_payload_length(&self) -> u64

Returns the payload_length of self.

fn wdm_payload_digest(&self) -> &PayloadDigest

Returns the payload_digest of self.

impl Entrylike<MCL, MCC, MPL, NamespaceId, SubspaceId, PayloadDigest> for Entry

fn wdm_payload_length(&self) -> u64

Returns the payload_length of self.

fn wdm_payload_digest(&self) -> &PayloadDigest

Returns the payload_digest of self.

impl Entrylike<MCL, MCC, MPL, NamespaceId, SubspaceId, PayloadDigest> for PossiblyAuthorisedEntry

fn wdm_payload_length(&self) -> u64

Returns the payload_length of self.

fn wdm_payload_digest(&self) -> &PayloadDigest

Returns the payload_digest of self.

impl From<[u8; 32]> for SubspaceId

fn from(value: [u8; 32]) -> Self

Converts to this type from the input type.

impl GreatestElement for SubspaceId

fn greatest() -> Self

Returns the unique greatest element.

fn is_greatest(&self) -> bool

Returns true if and only if self is the greatest element.

impl Hash for SubspaceId

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Keylike<MCL, MCC, MPL, SubspaceId> for (Path, SubspaceId)

fn wdm_subspace_id(&self) -> &SubspaceId

Returns the subspace_id of self.

fn wdm_path(&self) -> &Path<MCL, MCC, MPL>

Returns the path of self.

impl Keylike<MCL, MCC, MPL, SubspaceId> for (Path, SubspaceId, Timestamp)

fn wdm_subspace_id(&self) -> &SubspaceId

Returns the subspace_id of self.

fn wdm_path(&self) -> &Path<MCL, MCC, MPL>

Returns the path of self.

impl Keylike<MCL, MCC, MPL, SubspaceId> for (Path, Timestamp, SubspaceId)

fn wdm_subspace_id(&self) -> &SubspaceId

Returns the subspace_id of self.

fn wdm_path(&self) -> &Path<MCL, MCC, MPL>

Returns the path of self.

impl Keylike<MCL, MCC, MPL, SubspaceId> for (SubspaceId, Path)

fn wdm_subspace_id(&self) -> &SubspaceId

Returns the subspace_id of self.

fn wdm_path(&self) -> &Path<MCL, MCC, MPL>

Returns the path of self.

impl Keylike<MCL, MCC, MPL, SubspaceId> for (SubspaceId, Path, Timestamp)

fn wdm_subspace_id(&self) -> &SubspaceId

Returns the subspace_id of self.

fn wdm_path(&self) -> &Path<MCL, MCC, MPL>

Returns the path of self.

impl Keylike<MCL, MCC, MPL, SubspaceId> for (SubspaceId, Timestamp, Path)

fn wdm_subspace_id(&self) -> &SubspaceId

Returns the subspace_id of self.

fn wdm_path(&self) -> &Path<MCL, MCC, MPL>

Returns the path of self.

impl Keylike<MCL, MCC, MPL, SubspaceId> for (Timestamp, Path, SubspaceId)

fn wdm_subspace_id(&self) -> &SubspaceId

Returns the subspace_id of self.

fn wdm_path(&self) -> &Path<MCL, MCC, MPL>

Returns the path of self.

impl Keylike<MCL, MCC, MPL, SubspaceId> for (Timestamp, SubspaceId, Path)

fn wdm_subspace_id(&self) -> &SubspaceId

Returns the subspace_id of self.

fn wdm_path(&self) -> &Path<MCL, MCC, MPL>

Returns the path of self.

impl Keylike<MCL, MCC, MPL, SubspaceId> for AuthorisedEntry

fn wdm_subspace_id(&self) -> &SubspaceId

Returns the subspace_id of self.

fn wdm_path(&self) -> &Path<MCL, MCC, MPL>

Returns the path of self.

impl Keylike<MCL, MCC, MPL, SubspaceId> for Entry

fn wdm_subspace_id(&self) -> &SubspaceId

Returns the subspace_id of self.

fn wdm_path(&self) -> &Path<MCL, MCC, MPL>

Returns the path of self.

impl Keylike<MCL, MCC, MPL, SubspaceId> for PossiblyAuthorisedEntry

fn wdm_subspace_id(&self) -> &SubspaceId

Returns the subspace_id of self.

fn wdm_path(&self) -> &Path<MCL, MCC, MPL>

Returns the path of self.

impl LeastElement for SubspaceId

fn least() -> Self

Returns the unique least element.

fn is_least(&self) -> bool

Returns true if and only if self is the least element.

impl LowerSemilattice for SubspaceId

fn greatest_lower_bound(&self, other: &Self) -> Self

Returns the greatest lower bound of self and other, i.e., the unique greatest element in the type which is less than or equal to both self and other.

impl Ord for SubspaceId

Implemented lexicographically on the compressed Edwards y coordinate encoding.

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for SubspaceId

fn eq(&self, other: &SubspaceId) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for SubspaceId

Implemented lexicographically on the compressed Edwards y coordinate encoding.

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl RangeBounds<SubspaceId> for Area

fn start_bound(&self) -> Bound<&SubspaceId>

Start index bound.

fn end_bound(&self) -> Bound<&SubspaceId>

End index bound.

fn contains<U>(&self, item: &U) -> bool

where T: PartialOrd<U>, U: PartialOrd<T> + ?Sized,

Returns true if item is contained in the range.

fn is_empty(&self) -> bool

where T: PartialOrd,

🔬This is a nightly-only experimental API. (range_bounds_is_empty)

Returns true if the range contains no items. One-sided ranges (RangeFrom, etc) always return false.

impl RangeBounds<SubspaceId> for Range3d

fn start_bound(&self) -> Bound<&SubspaceId>

Start index bound.

fn end_bound(&self) -> Bound<&SubspaceId>

End index bound.

fn contains<U>(&self, item: &U) -> bool

where T: PartialOrd<U>, U: PartialOrd<T> + ?Sized,

Returns true if item is contained in the range.

fn is_empty(&self) -> bool

where T: PartialOrd,

🔬This is a nightly-only experimental API. (range_bounds_is_empty)

Returns true if the range contains no items. One-sided ranges (RangeFrom, etc) always return false.

impl TryPredecessor for SubspaceId

fn try_predecessor(&self) -> Option<Self>

If self has a predecessor, i.e., a unique greatest value which is strictly less than self, returns it. If there is no unique predecessor, returns None.

fn is_predecessor_of(&self, other: &Self) -> bool

Returns true iff self is the predecessor of other.

fn is_not_predecessor_of(&self, other: &Self) -> bool

Returns true iff self is not the predecessor of other.

impl TrySuccessor for SubspaceId

fn try_successor(&self) -> Option<Self>

If self has a successor, i.e., a unique least value which is strictly greater than self, returns it. If there is no unique successor, returns None.

fn is_successor_of(&self, other: &Self) -> bool

Returns true iff self is the successor of other.

fn is_not_successor_of(&self, other: &Self) -> bool

Returns true iff self is not the successor of other.

impl UpperSemilattice for SubspaceId

fn least_upper_bound(&self, other: &Self) -> Self

Returns the least upper bound of self and other, i.e., the unique least element in the type which is greater than or equal to both self and other.

impl Verifier<SubspaceSignature> for SubspaceId

fn verify(&self, msg: &[u8], signature: &SubspaceSignature) -> Result<(), Error>

Use Self to verify that the provided signature for a given message bytestring is authentic.

impl Eq for SubspaceId

impl PredecessorExceptForLeast for SubspaceId

impl StructuralPartialEq for SubspaceId

impl SuccessorExceptForGreatest for SubspaceId