//! Generated by `trust-tasks-codegen` — do not edit by hand.
//!
//! Spec slug: `rooms/keys/backfill`. Version: `0.2`.
/// Why this specification version is deprecated (SPEC "Superseded and
/// Withdrawn Versions"), or `None` while it is current.
pub const DEPRECATION: Option<&str> = None;
#[allow(unused_imports)]
use serde::{Deserialize, Serialize};
/// Error types.
pub mod error {
/// Error from a `TryFrom` or `FromStr` implementation.
pub struct ConversionError(::std::borrow::Cow<'static, str>);
impl ::std::error::Error for ConversionError {}
impl ::std::fmt::Display for ConversionError {
fn fmt(&self, f: &mut ::std::fmt::Formatter<'_>) -> Result<(), ::std::fmt::Error> {
::std::fmt::Display::fmt(&self.0, f)
}
}
impl ::std::fmt::Debug for ConversionError {
fn fmt(&self, f: &mut ::std::fmt::Formatter<'_>) -> Result<(), ::std::fmt::Error> {
::std::fmt::Debug::fmt(&self.0, f)
}
}
impl From<&'static str> for ConversionError {
fn from(value: &'static str) -> Self {
Self(value.into())
}
}
impl From<String> for ConversionError {
fn from(value: String) -> Self {
Self(value.into())
}
}
}
/**
The earliest epoch whose storage key a room still lets anybody derive: its chain was pruned below it (`rooms/epoch/prune`), and every epoch under it is meant to be unreadable — at the host, and, as far as each of them conforms, at every member's key holder. Absent means the room's chain has never been pruned.
**The off-by-one, stated once.** A rung (`EpochLink`) numbered `e` opens with epoch `e`'s key and yields epoch `e − 1`'s. A prune with `beforeEpoch: N` drops the rungs numbered below `N`, so rung `N` survives and still yields epoch `N − 1`'s key; the floor after it is therefore `N − 1`, never `N`. A party applying a floor `F` discards the rungs numbered `F` and below — rung `F` would yield `F − 1` — and every key for an epoch below `F`.
**Monotonic.** A floor only rises. A host raises the room's to the higher of the floor it held and `beforeEpoch − 1` at each prune it performs, and never lowers it; every other party keeps the highest it has learnt for the room, from any source, and never lowers it either. A lower floor learnt later — from a stale response, or a host that has not been pruned — changes nothing.
**A host** that holds a floor for a room MUST NOT store, accept or serve a rung numbered at or below it, and MUST serve the floor wherever a response can carry it (`rooms/epoch/chain` 0.2, `rooms/epoch/prune` 0.2).
**A member's key holder** — and any client of the member that keeps the room's rungs or keys itself — on learning a floor `F` above the one it held, by any means (`rooms/epoch/chain` 0.2 in its own reads, `rooms/keys/backfill` 0.2, `rooms/keys/chain` 0.2 from its principal):
1. MUST discard every rung it holds for the room numbered `F` or below, and every storage key, file key or other key material it holds or has cached for an epoch below `F` — including one it derived in passing while applying commits through those epochs (`rooms/keys/commit`, `rooms/epoch/commits`);
2. MUST NOT store such a rung or key again from any source — a delivery from its principal, a backfill, a repair, a catch-up, or a host that has not been pruned — and MUST NOT ask for one;
3. MUST refuse to derive or use a key for an epoch below `F`, answering exactly as it answers for an epoch its chain does not reach (`beyondChain`, with an earliest epoch at or above `F`), whatever it still holds;
4. MUST keep `F` itself for as long as it holds anything for the room, since it is what makes items 2 and 3 enforceable after the material is gone.
A key holder SHOULD learn the floor whenever it fetches rungs or catches up, and SHOULD ask for it — a `rooms/epoch/chain` 0.2 read carries it whatever `fromEpoch` and `limit` it names — at least as often as it otherwise reads the room. One that never asks never learns, and keeps what it held.
**What a floor does not do, stated plainly.** It is honoured by parties that conform; it does not reach into one that does not, and it recalls nothing. Plaintext a key holder already returned, records a member already opened, files already downloaded and decrypted, exports, and any key a member's own software extracted are beyond it. What it guarantees cryptographically is what the prune guarantees: a party that had not derived a key below the floor before the host erased its rungs can never derive it afterwards. What it adds is that every conforming key holder stops being able to — so that a restart, a new device or an agent's next recall reads nothing below the floor, rather than everything its holder happened to keep.*/
///
#[derive(::serde::Deserialize, ::serde::Serialize, Clone, Debug)]
#[serde(transparent)]
pub struct EpochFloor(pub ::std::num::NonZeroU64);
impl ::std::ops::Deref for EpochFloor {
type Target = ::std::num::NonZeroU64;
fn deref(&self) -> &::std::num::NonZeroU64 {
&self.0
}
}
impl ::std::convert::From<EpochFloor> for ::std::num::NonZeroU64 {
fn from(value: EpochFloor) -> Self {
value.0
}
}
impl ::std::convert::From<::std::num::NonZeroU64> for EpochFloor {
fn from(value: ::std::num::NonZeroU64) -> Self {
Self(value)
}
}
impl ::std::str::FromStr for EpochFloor {
type Err = <::std::num::NonZeroU64 as ::std::str::FromStr>::Err;
fn from_str(value: &str) -> ::std::result::Result<Self, Self::Err> {
Ok(Self(value.parse()?))
}
}
impl ::std::convert::TryFrom<&str> for EpochFloor {
type Error = <::std::num::NonZeroU64 as ::std::str::FromStr>::Err;
fn try_from(value: &str) -> ::std::result::Result<Self, Self::Error> {
value.parse()
}
}
impl ::std::convert::TryFrom<String> for EpochFloor {
type Error = <::std::num::NonZeroU64 as ::std::str::FromStr>::Err;
fn try_from(value: String) -> ::std::result::Result<Self, Self::Error> {
value.parse()
}
}
impl ::std::fmt::Display for EpochFloor {
fn fmt(&self, f: &mut ::std::fmt::Formatter<'_>) -> ::std::fmt::Result {
self.0.fmt(f)
}
}
///Vendor-namespaced extension object per SPEC.md §4.5.1. Each immediate key MUST be a reverse-DNS namespace; structure under each namespace is opaque to the framework.
///
#[derive(::serde::Deserialize, ::serde::Serialize, Clone, Debug)]
#[serde(transparent)]
pub struct Ext(pub ::std::collections::HashMap<ExtKey, ::serde_json::Value>);
impl ::std::ops::Deref for Ext {
type Target = ::std::collections::HashMap<ExtKey, ::serde_json::Value>;
fn deref(&self) -> &::std::collections::HashMap<ExtKey, ::serde_json::Value> {
&self.0
}
}
impl ::std::convert::From<Ext> for ::std::collections::HashMap<ExtKey, ::serde_json::Value> {
fn from(value: Ext) -> Self {
value.0
}
}
impl ::std::convert::From<::std::collections::HashMap<ExtKey, ::serde_json::Value>> for Ext {
fn from(value: ::std::collections::HashMap<ExtKey, ::serde_json::Value>) -> Self {
Self(value)
}
}
///`ExtKey`
///
#[derive(::serde::Serialize, Clone, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
#[serde(transparent)]
pub struct ExtKey(::std::string::String);
impl ::std::ops::Deref for ExtKey {
type Target = ::std::string::String;
fn deref(&self) -> &::std::string::String {
&self.0
}
}
impl ::std::convert::From<ExtKey> for ::std::string::String {
fn from(value: ExtKey) -> Self {
value.0
}
}
impl ::std::str::FromStr for ExtKey {
type Err = self::error::ConversionError;
fn from_str(value: &str) -> ::std::result::Result<Self, self::error::ConversionError> {
static PATTERN: ::std::sync::LazyLock<::regress::Regex> =
::std::sync::LazyLock::new(|| {
::regress::Regex::new("^[a-z][a-z0-9-]*(\\.[a-z0-9-]+)+$").unwrap()
});
if PATTERN.find(value).is_none() {
return Err("doesn't match pattern \"^[a-z][a-z0-9-]*(\\.[a-z0-9-]+)+$\"".into());
}
Ok(Self(value.to_string()))
}
}
impl ::std::convert::TryFrom<&str> for ExtKey {
type Error = self::error::ConversionError;
fn try_from(value: &str) -> ::std::result::Result<Self, self::error::ConversionError> {
value.parse()
}
}
impl ::std::convert::TryFrom<&::std::string::String> for ExtKey {
type Error = self::error::ConversionError;
fn try_from(
value: &::std::string::String,
) -> ::std::result::Result<Self, self::error::ConversionError> {
value.parse()
}
}
impl ::std::convert::TryFrom<::std::string::String> for ExtKey {
type Error = self::error::ConversionError;
fn try_from(
value: ::std::string::String,
) -> ::std::result::Result<Self, self::error::ConversionError> {
value.parse()
}
}
impl<'de> ::serde::Deserialize<'de> for ExtKey {
fn deserialize<D>(deserializer: D) -> ::std::result::Result<Self, D::Error>
where
D: ::serde::Deserializer<'de>,
{
::std::string::String::deserialize(deserializer)?
.parse()
.map_err(|e: self::error::ConversionError| {
<D::Error as ::serde::de::Error>::custom(e.to_string())
})
}
}
///`Payload`
///
#[derive(::serde::Deserialize, ::serde::Serialize, Clone, Debug)]
#[serde(deny_unknown_fields)]
#[non_exhaustive]
pub struct Payload {
///Ecosystem-defined extension members per SPEC.md §4.5.1.
#[serde(default, skip_serializing_if = "::std::option::Option::is_none")]
pub ext: ::std::option::Option<Ext>,
///Fetch only rungs at or below this epoch. Absent means from the room's current epoch down. A recipient that already reads to some epoch SHOULD pass it, so a host serves the part that is missing rather than the whole chain.
#[serde(
rename = "fromEpoch",
default,
skip_serializing_if = "::std::option::Option::is_none"
)]
pub from_epoch: ::std::option::Option<::std::num::NonZeroU64>,
///The host to fetch from, as a DID. Named by the caller because nothing maps a room to its host: a room is portable — re-point it and it has moved — so a remembered host is a value that goes stale, and the recipient holds key custody rather than a hosting record. A caller who names the wrong host learns so as a refusal from a party that does not serve this room, which is loud and immediate.
pub host: ::std::string::String,
///Maximum rungs to request in one pass, highest `epoch` first. A host MAY return fewer. A caller walking a long history calls again with `fromEpoch` set below what it has.
#[serde(default, skip_serializing_if = "::std::option::Option::is_none")]
pub limit: ::std::option::Option<::std::num::NonZeroU64>,
///The room to backfill. The recipient MUST already hold group state for it, and MUST NOT create any on the strength of this request: rungs are inert without an epoch key, so fetching them for a room one is not in would retain key material for nothing.
#[serde(rename = "roomId")]
pub room_id: ::std::string::String,
}
impl Payload {
pub fn builder() -> builder::Payload {
Default::default()
}
}
///Success response to rooms/keys/backfill. Type https://trusttasks.org/spec/rooms/keys/backfill/0.2#response.
///
#[derive(::serde::Deserialize, ::serde::Serialize, Clone, Debug)]
#[serde(deny_unknown_fields)]
#[non_exhaustive]
pub struct Response {
///The earliest epoch the recipient can now derive a key for, having walked what it holds. **This is the answer worth having**, and it is not derivable from `fetched`: a rung extends reach only if every rung above it is present, so a chain served with a gap in it moves this number not at all. `1` means the room's whole retained history is readable.
#[serde(rename = "earliestReadableEpoch")]
pub earliest_readable_epoch: ::std::num::NonZeroU64,
///The room's epoch floor the recipient now holds — the highest it has learnt, from this host or before. Absent when it holds none. When present, `earliestReadableEpoch` equal to it means the recipient reads everything the room still lets anybody read: the history below was pruned, not withheld.
#[serde(
rename = "epochFloor",
default,
skip_serializing_if = "::std::option::Option::is_none"
)]
pub epoch_floor: ::std::option::Option<EpochFloor>,
#[serde(default, skip_serializing_if = "::std::option::Option::is_none")]
pub ext: ::std::option::Option<Ext>,
///How many rungs the host served. Reported separately from `stored` and from the reach so a caller can tell the three ways this ends: nothing served (the host has no more), served and stored but the reach did not move (a gap), or served and the reach moved.
#[serde(default, skip_serializing_if = "::std::option::Option::is_none")]
pub fetched: ::std::option::Option<u64>,
#[serde(rename = "roomId")]
pub room_id: ::std::string::String,
///How many of them the recipient did not already hold and kept. Rungs numbered at or below the room's epoch floor are never kept or counted. Zero alongside a positive `fetched` means the chain was already delivered, which is what a retry looks like.
#[serde(default, skip_serializing_if = "::std::option::Option::is_none")]
pub stored: ::std::option::Option<u64>,
}
impl Response {
pub fn builder() -> builder::Response {
Default::default()
}
}
/// Types for composing complex structures.
pub mod builder {
#[derive(Clone, Debug)]
pub struct Payload {
ext: ::std::result::Result<::std::option::Option<super::Ext>, ::std::string::String>,
from_epoch: ::std::result::Result<
::std::option::Option<::std::num::NonZeroU64>,
::std::string::String,
>,
host: ::std::result::Result<::std::string::String, ::std::string::String>,
limit: ::std::result::Result<
::std::option::Option<::std::num::NonZeroU64>,
::std::string::String,
>,
room_id: ::std::result::Result<::std::string::String, ::std::string::String>,
}
impl ::std::default::Default for Payload {
fn default() -> Self {
Self {
ext: Ok(Default::default()),
from_epoch: Ok(Default::default()),
host: Err("no value supplied for host".to_string()),
limit: Ok(Default::default()),
room_id: Err("no value supplied for room_id".to_string()),
}
}
}
impl Payload {
pub fn ext<T>(mut self, value: T) -> Self
where
T: ::std::convert::TryInto<::std::option::Option<super::Ext>>,
T::Error: ::std::fmt::Display,
{
self.ext = value
.try_into()
.map_err(|e| format!("error converting supplied value for ext: {e}"));
self
}
pub fn from_epoch<T>(mut self, value: T) -> Self
where
T: ::std::convert::TryInto<::std::option::Option<::std::num::NonZeroU64>>,
T::Error: ::std::fmt::Display,
{
self.from_epoch = value
.try_into()
.map_err(|e| format!("error converting supplied value for from_epoch: {e}"));
self
}
pub fn host<T>(mut self, value: T) -> Self
where
T: ::std::convert::TryInto<::std::string::String>,
T::Error: ::std::fmt::Display,
{
self.host = value
.try_into()
.map_err(|e| format!("error converting supplied value for host: {e}"));
self
}
pub fn limit<T>(mut self, value: T) -> Self
where
T: ::std::convert::TryInto<::std::option::Option<::std::num::NonZeroU64>>,
T::Error: ::std::fmt::Display,
{
self.limit = value
.try_into()
.map_err(|e| format!("error converting supplied value for limit: {e}"));
self
}
pub fn room_id<T>(mut self, value: T) -> Self
where
T: ::std::convert::TryInto<::std::string::String>,
T::Error: ::std::fmt::Display,
{
self.room_id = value
.try_into()
.map_err(|e| format!("error converting supplied value for room_id: {e}"));
self
}
}
impl ::std::convert::TryFrom<Payload> for super::Payload {
type Error = super::error::ConversionError;
fn try_from(value: Payload) -> ::std::result::Result<Self, super::error::ConversionError> {
Ok(Self {
ext: value.ext?,
from_epoch: value.from_epoch?,
host: value.host?,
limit: value.limit?,
room_id: value.room_id?,
})
}
}
impl ::std::convert::From<super::Payload> for Payload {
fn from(value: super::Payload) -> Self {
Self {
ext: Ok(value.ext),
from_epoch: Ok(value.from_epoch),
host: Ok(value.host),
limit: Ok(value.limit),
room_id: Ok(value.room_id),
}
}
}
#[derive(Clone, Debug)]
pub struct Response {
earliest_readable_epoch:
::std::result::Result<::std::num::NonZeroU64, ::std::string::String>,
epoch_floor:
::std::result::Result<::std::option::Option<super::EpochFloor>, ::std::string::String>,
ext: ::std::result::Result<::std::option::Option<super::Ext>, ::std::string::String>,
fetched: ::std::result::Result<::std::option::Option<u64>, ::std::string::String>,
room_id: ::std::result::Result<::std::string::String, ::std::string::String>,
stored: ::std::result::Result<::std::option::Option<u64>, ::std::string::String>,
}
impl ::std::default::Default for Response {
fn default() -> Self {
Self {
earliest_readable_epoch: Err(
"no value supplied for earliest_readable_epoch".to_string()
),
epoch_floor: Ok(Default::default()),
ext: Ok(Default::default()),
fetched: Ok(Default::default()),
room_id: Err("no value supplied for room_id".to_string()),
stored: Ok(Default::default()),
}
}
}
impl Response {
pub fn earliest_readable_epoch<T>(mut self, value: T) -> Self
where
T: ::std::convert::TryInto<::std::num::NonZeroU64>,
T::Error: ::std::fmt::Display,
{
self.earliest_readable_epoch = value.try_into().map_err(|e| {
format!("error converting supplied value for earliest_readable_epoch: {e}")
});
self
}
pub fn epoch_floor<T>(mut self, value: T) -> Self
where
T: ::std::convert::TryInto<::std::option::Option<super::EpochFloor>>,
T::Error: ::std::fmt::Display,
{
self.epoch_floor = value
.try_into()
.map_err(|e| format!("error converting supplied value for epoch_floor: {e}"));
self
}
pub fn ext<T>(mut self, value: T) -> Self
where
T: ::std::convert::TryInto<::std::option::Option<super::Ext>>,
T::Error: ::std::fmt::Display,
{
self.ext = value
.try_into()
.map_err(|e| format!("error converting supplied value for ext: {e}"));
self
}
pub fn fetched<T>(mut self, value: T) -> Self
where
T: ::std::convert::TryInto<::std::option::Option<u64>>,
T::Error: ::std::fmt::Display,
{
self.fetched = value
.try_into()
.map_err(|e| format!("error converting supplied value for fetched: {e}"));
self
}
pub fn room_id<T>(mut self, value: T) -> Self
where
T: ::std::convert::TryInto<::std::string::String>,
T::Error: ::std::fmt::Display,
{
self.room_id = value
.try_into()
.map_err(|e| format!("error converting supplied value for room_id: {e}"));
self
}
pub fn stored<T>(mut self, value: T) -> Self
where
T: ::std::convert::TryInto<::std::option::Option<u64>>,
T::Error: ::std::fmt::Display,
{
self.stored = value
.try_into()
.map_err(|e| format!("error converting supplied value for stored: {e}"));
self
}
}
impl ::std::convert::TryFrom<Response> for super::Response {
type Error = super::error::ConversionError;
fn try_from(value: Response) -> ::std::result::Result<Self, super::error::ConversionError> {
Ok(Self {
earliest_readable_epoch: value.earliest_readable_epoch?,
epoch_floor: value.epoch_floor?,
ext: value.ext?,
fetched: value.fetched?,
room_id: value.room_id?,
stored: value.stored?,
})
}
}
impl ::std::convert::From<super::Response> for Response {
fn from(value: super::Response) -> Self {
Self {
earliest_readable_epoch: Ok(value.earliest_readable_epoch),
epoch_floor: Ok(value.epoch_floor),
ext: Ok(value.ext),
fetched: Ok(value.fetched),
room_id: Ok(value.room_id),
stored: Ok(value.stored),
}
}
}
}
impl crate::Payload for Payload {
const TYPE_URI: &'static str = "https://trusttasks.org/spec/rooms/keys/backfill/0.2";
const IS_PROOF_REQUIRED: bool = true;
const IS_ISSUED_AT_REQUIRED: bool = true;
const IS_RECIPIENT_REQUIRED: bool = true;
const PAYLOAD_SCHEMA: Option<&'static str> = Some(
"{\"$defs\":{\"EpochFloor\":{\"description\":\"The earliest epoch whose storage key a room still lets anybody derive: its chain was pruned below it (`rooms/epoch/prune`), and every epoch under it is meant to be unreadable — at the host, and, as far as each of them conforms, at every member's key holder. Absent means the room's chain has never been pruned.\\n\\n**The off-by-one, stated once.** A rung (`EpochLink`) numbered `e` opens with epoch `e`'s key and yields epoch `e − 1`'s. A prune with `beforeEpoch: N` drops the rungs numbered below `N`, so rung `N` survives and still yields epoch `N − 1`'s key; the floor after it is therefore `N − 1`, never `N`. A party applying a floor `F` discards the rungs numbered `F` and below — rung `F` would yield `F − 1` — and every key for an epoch below `F`.\\n\\n**Monotonic.** A floor only rises. A host raises the room's to the higher of the floor it held and `beforeEpoch − 1` at each prune it performs, and never lowers it; every other party keeps the highest it has learnt for the room, from any source, and never lowers it either. A lower floor learnt later — from a stale response, or a host that has not been pruned — changes nothing.\\n\\n**A host** that holds a floor for a room MUST NOT store, accept or serve a rung numbered at or below it, and MUST serve the floor wherever a response can carry it (`rooms/epoch/chain` 0.2, `rooms/epoch/prune` 0.2).\\n\\n**A member's key holder** — and any client of the member that keeps the room's rungs or keys itself — on learning a floor `F` above the one it held, by any means (`rooms/epoch/chain` 0.2 in its own reads, `rooms/keys/backfill` 0.2, `rooms/keys/chain` 0.2 from its principal):\\n 1. MUST discard every rung it holds for the room numbered `F` or below, and every storage key, file key or other key material it holds or has cached for an epoch below `F` — including one it derived in passing while applying commits through those epochs (`rooms/keys/commit`, `rooms/epoch/commits`);\\n 2. MUST NOT store such a rung or key again from any source — a delivery from its principal, a backfill, a repair, a catch-up, or a host that has not been pruned — and MUST NOT ask for one;\\n 3. MUST refuse to derive or use a key for an epoch below `F`, answering exactly as it answers for an epoch its chain does not reach (`beyondChain`, with an earliest epoch at or above `F`), whatever it still holds;\\n 4. MUST keep `F` itself for as long as it holds anything for the room, since it is what makes items 2 and 3 enforceable after the material is gone.\\n\\nA key holder SHOULD learn the floor whenever it fetches rungs or catches up, and SHOULD ask for it — a `rooms/epoch/chain` 0.2 read carries it whatever `fromEpoch` and `limit` it names — at least as often as it otherwise reads the room. One that never asks never learns, and keeps what it held.\\n\\n**What a floor does not do, stated plainly.** It is honoured by parties that conform; it does not reach into one that does not, and it recalls nothing. Plaintext a key holder already returned, records a member already opened, files already downloaded and decrypted, exports, and any key a member's own software extracted are beyond it. What it guarantees cryptographically is what the prune guarantees: a party that had not derived a key below the floor before the host erased its rungs can never derive it afterwards. What it adds is that every conforming key holder stops being able to — so that a restart, a new device or an agent's next recall reads nothing below the floor, rather than everything its holder happened to keep.\",\"minimum\":1,\"title\":\"EpochFloor\",\"type\":\"integer\"},\"Ext\":{\"additionalProperties\":true,\"description\":\"Vendor-namespaced extension object per SPEC.md §4.5.1. Each immediate key MUST be a reverse-DNS namespace; structure under each namespace is opaque to the framework.\",\"minProperties\":1,\"propertyNames\":{\"pattern\":\"^[a-z][a-z0-9-]*(\\\\.[a-z0-9-]+)+$\"},\"title\":\"Ext\",\"type\":\"object\"},\"Response\":{\"$anchor\":\"response\",\"additionalProperties\":false,\"description\":\"Success response to rooms/keys/backfill. Type https://trusttasks.org/spec/rooms/keys/backfill/0.2#response.\",\"properties\":{\"earliestReadableEpoch\":{\"description\":\"The earliest epoch the recipient can now derive a key for, having walked what it holds. **This is the answer worth having**, and it is not derivable from `fetched`: a rung extends reach only if every rung above it is present, so a chain served with a gap in it moves this number not at all. `1` means the room's whole retained history is readable.\",\"minimum\":1,\"type\":\"integer\"},\"epochFloor\":{\"$ref\":\"#/$defs/EpochFloor\",\"description\":\"The room's epoch floor the recipient now holds — the highest it has learnt, from this host or before. Absent when it holds none. When present, `earliestReadableEpoch` equal to it means the recipient reads everything the room still lets anybody read: the history below was pruned, not withheld.\"},\"ext\":{\"$ref\":\"#/$defs/Ext\"},\"fetched\":{\"description\":\"How many rungs the host served. Reported separately from `stored` and from the reach so a caller can tell the three ways this ends: nothing served (the host has no more), served and stored but the reach did not move (a gap), or served and the reach moved.\",\"minimum\":0,\"type\":\"integer\"},\"roomId\":{\"type\":\"string\"},\"stored\":{\"description\":\"How many of them the recipient did not already hold and kept. Rungs numbered at or below the room's epoch floor are never kept or counted. Zero alongside a positive `fetched` means the chain was already delivered, which is what a retry looks like.\",\"minimum\":0,\"type\":\"integer\"}},\"required\":[\"roomId\",\"earliestReadableEpoch\"],\"title\":\"Rooms Keys Backfill — response payload\",\"type\":\"object\"}},\"$id\":\"https://trusttasks.org/spec/rooms/keys/backfill/0.2\",\"$schema\":\"https://json-schema.org/draft/2020-12/schema\",\"additionalProperties\":false,\"properties\":{\"ext\":{\"$ref\":\"#/$defs/Ext\",\"description\":\"Ecosystem-defined extension members per SPEC.md §4.5.1.\"},\"fromEpoch\":{\"description\":\"Fetch only rungs at or below this epoch. Absent means from the room's current epoch down. A recipient that already reads to some epoch SHOULD pass it, so a host serves the part that is missing rather than the whole chain.\",\"minimum\":1,\"type\":\"integer\"},\"host\":{\"description\":\"The host to fetch from, as a DID. Named by the caller because nothing maps a room to its host: a room is portable — re-point it and it has moved — so a remembered host is a value that goes stale, and the recipient holds key custody rather than a hosting record. A caller who names the wrong host learns so as a refusal from a party that does not serve this room, which is loud and immediate.\",\"type\":\"string\"},\"limit\":{\"description\":\"Maximum rungs to request in one pass, highest `epoch` first. A host MAY return fewer. A caller walking a long history calls again with `fromEpoch` set below what it has.\",\"minimum\":1,\"type\":\"integer\"},\"roomId\":{\"description\":\"The room to backfill. The recipient MUST already hold group state for it, and MUST NOT create any on the strength of this request: rungs are inert without an epoch key, so fetching them for a room one is not in would retain key material for nothing.\",\"type\":\"string\"}},\"required\":[\"roomId\",\"host\"],\"title\":\"Rooms Keys Backfill — payload\",\"type\":\"object\"}\n",
);
}
impl crate::Payload for Response {
const TYPE_URI: &'static str = "https://trusttasks.org/spec/rooms/keys/backfill/0.2#response";
const IS_PROOF_REQUIRED: bool = true;
const IS_ISSUED_AT_REQUIRED: bool = true;
const IS_RECIPIENT_REQUIRED: bool = true;
const PAYLOAD_SCHEMA: Option<&'static str> = Some(
"{\"$defs\":{\"EpochFloor\":{\"description\":\"The earliest epoch whose storage key a room still lets anybody derive: its chain was pruned below it (`rooms/epoch/prune`), and every epoch under it is meant to be unreadable — at the host, and, as far as each of them conforms, at every member's key holder. Absent means the room's chain has never been pruned.\\n\\n**The off-by-one, stated once.** A rung (`EpochLink`) numbered `e` opens with epoch `e`'s key and yields epoch `e − 1`'s. A prune with `beforeEpoch: N` drops the rungs numbered below `N`, so rung `N` survives and still yields epoch `N − 1`'s key; the floor after it is therefore `N − 1`, never `N`. A party applying a floor `F` discards the rungs numbered `F` and below — rung `F` would yield `F − 1` — and every key for an epoch below `F`.\\n\\n**Monotonic.** A floor only rises. A host raises the room's to the higher of the floor it held and `beforeEpoch − 1` at each prune it performs, and never lowers it; every other party keeps the highest it has learnt for the room, from any source, and never lowers it either. A lower floor learnt later — from a stale response, or a host that has not been pruned — changes nothing.\\n\\n**A host** that holds a floor for a room MUST NOT store, accept or serve a rung numbered at or below it, and MUST serve the floor wherever a response can carry it (`rooms/epoch/chain` 0.2, `rooms/epoch/prune` 0.2).\\n\\n**A member's key holder** — and any client of the member that keeps the room's rungs or keys itself — on learning a floor `F` above the one it held, by any means (`rooms/epoch/chain` 0.2 in its own reads, `rooms/keys/backfill` 0.2, `rooms/keys/chain` 0.2 from its principal):\\n 1. MUST discard every rung it holds for the room numbered `F` or below, and every storage key, file key or other key material it holds or has cached for an epoch below `F` — including one it derived in passing while applying commits through those epochs (`rooms/keys/commit`, `rooms/epoch/commits`);\\n 2. MUST NOT store such a rung or key again from any source — a delivery from its principal, a backfill, a repair, a catch-up, or a host that has not been pruned — and MUST NOT ask for one;\\n 3. MUST refuse to derive or use a key for an epoch below `F`, answering exactly as it answers for an epoch its chain does not reach (`beyondChain`, with an earliest epoch at or above `F`), whatever it still holds;\\n 4. MUST keep `F` itself for as long as it holds anything for the room, since it is what makes items 2 and 3 enforceable after the material is gone.\\n\\nA key holder SHOULD learn the floor whenever it fetches rungs or catches up, and SHOULD ask for it — a `rooms/epoch/chain` 0.2 read carries it whatever `fromEpoch` and `limit` it names — at least as often as it otherwise reads the room. One that never asks never learns, and keeps what it held.\\n\\n**What a floor does not do, stated plainly.** It is honoured by parties that conform; it does not reach into one that does not, and it recalls nothing. Plaintext a key holder already returned, records a member already opened, files already downloaded and decrypted, exports, and any key a member's own software extracted are beyond it. What it guarantees cryptographically is what the prune guarantees: a party that had not derived a key below the floor before the host erased its rungs can never derive it afterwards. What it adds is that every conforming key holder stops being able to — so that a restart, a new device or an agent's next recall reads nothing below the floor, rather than everything its holder happened to keep.\",\"minimum\":1,\"title\":\"EpochFloor\",\"type\":\"integer\"},\"Ext\":{\"additionalProperties\":true,\"description\":\"Vendor-namespaced extension object per SPEC.md §4.5.1. Each immediate key MUST be a reverse-DNS namespace; structure under each namespace is opaque to the framework.\",\"minProperties\":1,\"propertyNames\":{\"pattern\":\"^[a-z][a-z0-9-]*(\\\\.[a-z0-9-]+)+$\"},\"title\":\"Ext\",\"type\":\"object\"},\"Response\":{\"$anchor\":\"response\",\"additionalProperties\":false,\"description\":\"Success response to rooms/keys/backfill. Type https://trusttasks.org/spec/rooms/keys/backfill/0.2#response.\",\"properties\":{\"earliestReadableEpoch\":{\"description\":\"The earliest epoch the recipient can now derive a key for, having walked what it holds. **This is the answer worth having**, and it is not derivable from `fetched`: a rung extends reach only if every rung above it is present, so a chain served with a gap in it moves this number not at all. `1` means the room's whole retained history is readable.\",\"minimum\":1,\"type\":\"integer\"},\"epochFloor\":{\"$ref\":\"#/$defs/EpochFloor\",\"description\":\"The room's epoch floor the recipient now holds — the highest it has learnt, from this host or before. Absent when it holds none. When present, `earliestReadableEpoch` equal to it means the recipient reads everything the room still lets anybody read: the history below was pruned, not withheld.\"},\"ext\":{\"$ref\":\"#/$defs/Ext\"},\"fetched\":{\"description\":\"How many rungs the host served. Reported separately from `stored` and from the reach so a caller can tell the three ways this ends: nothing served (the host has no more), served and stored but the reach did not move (a gap), or served and the reach moved.\",\"minimum\":0,\"type\":\"integer\"},\"roomId\":{\"type\":\"string\"},\"stored\":{\"description\":\"How many of them the recipient did not already hold and kept. Rungs numbered at or below the room's epoch floor are never kept or counted. Zero alongside a positive `fetched` means the chain was already delivered, which is what a retry looks like.\",\"minimum\":0,\"type\":\"integer\"}},\"required\":[\"roomId\",\"earliestReadableEpoch\"],\"title\":\"Rooms Keys Backfill — response payload\",\"type\":\"object\"}},\"$ref\":\"#/$defs/Response\",\"$schema\":\"https://json-schema.org/draft/2020-12/schema\"}\n",
);
}
impl crate::RequestPayload for Payload {
type Response = Response;
}
/// The earlier `MAJOR.MINOR` of this slug that this version declares it
/// extends (front matter `extends`, SPEC §5.2 "Declared extension"), or
/// `None`. Only the direct declaration; walk a chain with
/// [`crate::extension::extends_for`].
pub const EXTENDS: Option<&str> = None;
/// The extended error codes this specification declares (SPEC §7.3 item 9,
/// §8.5), in declaration order. Empty when it declares none.
pub const ERROR_CODES: &[crate::DeclaredErrorCode] = &[
error_codes::NOT_A_MEMBER,
error_codes::HOST_UNREACHABLE,
error_codes::HOST_REFUSED,
];
/// One constant per extended error code this specification declares
/// (SPEC §7.3 item 9), named for its local part.
///
/// Emit these rather than a string literal: the code is read from the
/// specification, so it cannot name a code the specification never
/// declared.
pub mod error_codes {
/// `rooms/keys/backfill:notAMember`
///
/// The recipient holds no group state for this room, so there is nothing for the rungs to extend and no credentials to present.
///
/// Declared `retryable: false`.
pub const NOT_A_MEMBER: crate::DeclaredErrorCode = crate::DeclaredErrorCode {
code: "rooms/keys/backfill:notAMember",
retryable: false,
details_schema: ::core::option::Option::None,
};
/// `rooms/keys/backfill:hostUnreachable`
///
/// The named host could not be resolved, advertises no transport this recipient speaks, or did not answer.
///
/// Declared `retryable: true`.
pub const HOST_UNREACHABLE: crate::DeclaredErrorCode = crate::DeclaredErrorCode {
code: "rooms/keys/backfill:hostUnreachable",
retryable: true,
details_schema: ::core::option::Option::None,
};
/// `rooms/keys/backfill:hostRefused`
///
/// The host answered and declined. Its own reason is carried in `details`; the commonest is that this host does not serve the named room.
///
/// Declared `retryable: false`.
pub const HOST_REFUSED: crate::DeclaredErrorCode = crate::DeclaredErrorCode {
code: "rooms/keys/backfill:hostRefused",
retryable: false,
details_schema: ::core::option::Option::None,
};
}