1025 lines
35 KiB
Rust
1025 lines
35 KiB
Rust
//! Functions for signing and verifying JSON and events.
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use std::{
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collections::{BTreeMap, BTreeSet},
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mem,
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str::FromStr,
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};
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use base64::{decode_config, encode_config, STANDARD_NO_PAD, URL_SAFE_NO_PAD};
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use ring::digest::{digest, SHA256};
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use ruma_identifiers::{EventId, RoomVersionId, ServerNameBox, UserId};
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use ruma_serde::{to_canonical_json_string, CanonicalJsonObject, CanonicalJsonValue};
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use serde_json::from_str as from_json_str;
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use crate::{
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keys::{KeyPair, PublicKeyMap},
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split_id,
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verification::{Ed25519Verifier, Verified, Verifier},
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Error,
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};
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/// The fields that are allowed to remain in an event during redaction.
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static ALLOWED_KEYS: &[&str] = &[
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"event_id",
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"type",
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"room_id",
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"sender",
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"state_key",
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"content",
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"hashes",
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"signatures",
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"depth",
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"prev_events",
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"prev_state",
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"auth_events",
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"origin",
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"origin_server_ts",
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"membership",
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];
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fn allowed_content_keys_for(event_type: &str, version: &RoomVersionId) -> &'static [&'static str] {
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match event_type {
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"m.room.member" => &["membership"],
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"m.room.create" => &["creator"],
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"m.room.join_rules" => &["join_rule"],
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"m.room.power_levels" => &[
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"ban",
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"events",
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"events_default",
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"kick",
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"redact",
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"state_default",
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"users",
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"users_default",
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],
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"m.room.aliases" => match version {
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RoomVersionId::Version1
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| RoomVersionId::Version2
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| RoomVersionId::Version3
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| RoomVersionId::Version4
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| RoomVersionId::Version5 => &["aliases"],
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// All other room versions, including custom ones, are treated by version 6 rules.
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// TODO: Should we return an error for unknown versions instead?
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_ => &[],
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},
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"m.room.history_visibility" => &["history_visibility"],
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_ => &[],
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}
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}
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/// The fields to remove from a JSON object when converting JSON into the "canonical" form.
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static CANONICAL_JSON_FIELDS_TO_REMOVE: &[&str] = &["signatures", "unsigned"];
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/// The fields to remove from a JSON object when creating a content hash of an event.
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static CONTENT_HASH_FIELDS_TO_REMOVE: &[&str] = &["hashes", "signatures", "unsigned"];
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/// The fields to remove from a JSON object when creating a reference hash of an event.
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static REFERENCE_HASH_FIELDS_TO_REMOVE: &[&str] = &["age_ts", "signatures", "unsigned"];
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/// Signs an arbitrary JSON object and adds the signature to an object under the key `signatures`.
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///
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/// If `signatures` is already present, the new signature will be appended to the existing ones.
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///
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/// # Parameters
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///
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/// * entity_id: The identifier of the entity creating the signature. Generally this means a
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/// homeserver, e.g. "example.com".
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/// * key_pair: A cryptographic key pair used to sign the JSON.
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/// * object: A JSON object to sign according and append a signature to.
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///
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/// # Errors
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///
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/// Returns an error if:
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///
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/// * `object` contains a field called `signatures` that is not a JSON object.
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///
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/// # Examples
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///
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/// A homeserver signs JSON with a key pair:
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///
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/// ```rust
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/// const PKCS8: &str = "\
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/// MFMCAQEwBQYDK2VwBCIEINjozvdfbsGEt6DD+7Uf4PiJ/YvTNXV2mIPc/\
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/// tA0T+6toSMDIQDdM+tpNzNWQM9NFpfgr4B9S7LHszOrVRp9NfKmeXS3aQ\
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/// ";
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///
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/// let document = base64::decode_config(&PKCS8, base64::STANDARD_NO_PAD).unwrap();
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///
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/// // Create an Ed25519 key pair.
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/// let key_pair = ruma_signatures::Ed25519KeyPair::new(
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/// &document,
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/// "1".into(), // The "version" of the key.
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/// ).unwrap();
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///
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/// // Deserialize some JSON.
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/// let mut value = serde_json::from_str("{}").unwrap();
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///
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/// // Sign the JSON with the key pair.
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/// assert!(ruma_signatures::sign_json("domain", &key_pair, &mut value).is_ok());
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/// ```
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///
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/// This will modify the JSON from an empty object to a structure like this:
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///
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/// ```json
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/// {
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/// "signatures": {
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/// "domain": {
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/// "ed25519:1": "K8280/U9SSy9IVtjBuVeLr+HpOB4BQFWbg+UZaADMtTdGYI7Geitb76LTrr5QV/7Xg4ahLwYGYZzuHGZKM5ZAQ"
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/// }
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/// }
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/// }
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/// ```
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pub fn sign_json<K>(
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entity_id: &str,
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key_pair: &K,
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object: &mut CanonicalJsonObject,
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) -> Result<(), Error>
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where
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K: KeyPair,
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{
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let mut signature_map;
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let maybe_unsigned;
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// FIXME: Once MSRV >= 1.45.0, use remove_key and don't allocate new `String`s below.
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signature_map = match object.remove("signatures") {
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Some(CanonicalJsonValue::Object(signatures)) => signatures,
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Some(_) => return Err(Error::new("field `signatures` must be a JSON object")),
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None => BTreeMap::new(),
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};
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maybe_unsigned = object.remove("unsigned");
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// Get the canonical JSON string.
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let json = to_canonical_json_string(object)?;
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// Sign the canonical JSON string.
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let signature = key_pair.sign(json.as_bytes());
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// Insert the new signature in the map we pulled out (or created) previously.
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let signature_set = signature_map
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.entry(entity_id.to_string())
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.or_insert_with(|| CanonicalJsonValue::Object(BTreeMap::new()));
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let signature_set = match signature_set {
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CanonicalJsonValue::Object(obj) => obj,
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_ => return Err(Error::new("fields in `signatures` must be objects")),
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};
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signature_set.insert(signature.id(), CanonicalJsonValue::String(signature.base64()));
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// Put `signatures` and `unsigned` back in.
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object.insert("signatures".into(), CanonicalJsonValue::Object(signature_map));
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if let Some(unsigned) = maybe_unsigned {
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object.insert("unsigned".into(), unsigned);
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}
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Ok(())
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}
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/// Converts an event into the [canonical] string form.
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///
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/// [canonical]: https://matrix.org/docs/spec/appendices#canonical-json
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///
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/// # Parameters
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///
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/// * object: The JSON object to convert.
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///
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/// # Examples
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///
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/// ```rust
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/// let input =
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/// r#"{
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/// "本": 2,
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/// "日": 1
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/// }"#;
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///
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/// let object = serde_json::from_str(input).unwrap();
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/// let canonical = ruma_signatures::canonical_json(&object);
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///
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/// assert_eq!(canonical, r#"{"日":1,"本":2}"#);
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/// ```
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pub fn canonical_json(object: &CanonicalJsonObject) -> String {
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canonical_json_with_fields_to_remove(object, CANONICAL_JSON_FIELDS_TO_REMOVE)
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}
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/// Uses a set of public keys to verify a signed JSON object.
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///
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/// # Parameters
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///
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/// * public_key_map: A map from entity identifiers to a map from key identifiers to public keys.
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/// Generally, entity identifiers are server names—the host/IP/port of a homeserver (e.g.
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/// "example.com") for which a signature must be verified. Key identifiers for each server (e.g.
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/// "ed25519:1") then map to their respective public keys.
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/// * object: The JSON object that was signed.
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///
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/// # Errors
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///
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/// Returns an error if verification fails.
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///
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/// # Examples
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///
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/// ```rust
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/// use std::collections::BTreeMap;
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///
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/// const PUBLIC_KEY: &str = "XGX0JRS2Af3be3knz2fBiRbApjm2Dh61gXDJA8kcJNI";
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///
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/// // Deserialize the signed JSON.
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/// let object = serde_json::from_str(
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/// r#"{
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/// "signatures": {
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/// "domain": {
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/// "ed25519:1": "K8280/U9SSy9IVtjBuVeLr+HpOB4BQFWbg+UZaADMtTdGYI7Geitb76LTrr5QV/7Xg4ahLwYGYZzuHGZKM5ZAQ"
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/// }
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/// }
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/// }"#
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/// ).unwrap();
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///
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/// // Create the `PublicKeyMap` that will inform `verify_json` which signatures to verify.
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/// let mut public_key_set = BTreeMap::new();
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/// public_key_set.insert("ed25519:1".into(), PUBLIC_KEY.to_string());
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/// let mut public_key_map = BTreeMap::new();
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/// public_key_map.insert("domain".into(), public_key_set);
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///
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/// // Verify at least one signature for each entity in `public_key_map`.
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/// assert!(ruma_signatures::verify_json(&public_key_map, &object).is_ok());
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/// ```
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pub fn verify_json(
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public_key_map: &PublicKeyMap,
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object: &CanonicalJsonObject,
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) -> Result<(), Error> {
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let signature_map = match object.get("signatures") {
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Some(CanonicalJsonValue::Object(signatures)) => signatures.clone(),
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Some(_) => return Err(Error::new("field `signatures` must be a JSON object")),
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None => return Err(Error::new("JSON object must contain a `signatures` field.")),
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};
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for (entity_id, public_keys) in public_key_map {
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let signature_set = match signature_map.get(entity_id) {
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Some(CanonicalJsonValue::Object(set)) => set,
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Some(_) => return Err(Error::new("signature sets must be JSON objects")),
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None => {
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return Err(Error::new(format!("no signatures found for entity `{}`", entity_id)))
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}
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};
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let mut maybe_signature = None;
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let mut maybe_public_key = None;
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for (key_id, public_key) in public_keys {
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// Since only ed25519 is supported right now, we don't actually need to check what the
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// algorithm is. If it split successfully, it's ed25519.
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if split_id(key_id).is_err() {
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break;
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}
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if let Some(signature) = signature_set.get(key_id) {
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maybe_signature = Some(signature);
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maybe_public_key = Some(public_key);
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break;
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}
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}
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let signature = match maybe_signature {
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Some(CanonicalJsonValue::String(signature)) => signature,
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Some(_) => return Err(Error::new("signature must be a string")),
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None => {
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return Err(Error::new("event is not signed with any of the given public keys"))
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}
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};
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let public_key = match maybe_public_key {
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Some(public_key) => public_key,
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None => {
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return Err(Error::new("event is not signed with any of the given public keys"))
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}
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};
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let signature_bytes = decode_config(signature, STANDARD_NO_PAD)?;
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let public_key_bytes = decode_config(&public_key, STANDARD_NO_PAD)?;
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verify_json_with(&Ed25519Verifier, &public_key_bytes, &signature_bytes, object)?;
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}
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Ok(())
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}
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/// Uses a public key to verify a signed JSON object.
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///
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/// # Parameters
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///
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/// * verifier: A `Verifier` appropriate for the digital signature algorithm that was used.
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/// * public_key: The raw bytes of the public key used to sign the JSON.
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/// * signature: The raw bytes of the signature.
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/// * object: The JSON object that was signed.
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///
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/// # Errors
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///
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/// Returns an error if verification fails.
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fn verify_json_with<V>(
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verifier: &V,
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public_key: &[u8],
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signature: &[u8],
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object: &CanonicalJsonObject,
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) -> Result<(), Error>
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where
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V: Verifier,
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{
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verifier.verify_json(public_key, signature, canonical_json(object).as_bytes())
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}
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/// Creates a *content hash* for an event.
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///
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/// Returns the hash as a Base64-encoded string, using the standard character set, without padding.
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///
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/// The content hash of an event covers the complete event including the unredacted contents. It is
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/// used during federation and is described in the Matrix server-server specification.
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///
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/// # Parameters
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///
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/// object: A JSON object to generate a content hash for.
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pub fn content_hash(object: &CanonicalJsonObject) -> String {
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let json = canonical_json_with_fields_to_remove(object, CONTENT_HASH_FIELDS_TO_REMOVE);
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let hash = digest(&SHA256, json.as_bytes());
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encode_config(&hash, STANDARD_NO_PAD)
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}
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/// Creates a *reference hash* for an event.
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///
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/// Returns the hash as a Base64-encoded string, using the standard character set, without padding.
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///
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/// The reference hash of an event covers the essential fields of an event, including content
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/// hashes. It is used to generate event identifiers and is described in the Matrix server-server
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/// specification.
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///
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/// # Parameters
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///
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/// object: A JSON object to generate a reference hash for.
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///
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/// # Errors
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///
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/// Returns an error if redaction fails.
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pub fn reference_hash(
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value: &CanonicalJsonObject,
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version: &RoomVersionId,
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) -> Result<String, Error> {
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let redacted_value = redact(value, version)?;
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let json =
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canonical_json_with_fields_to_remove(&redacted_value, REFERENCE_HASH_FIELDS_TO_REMOVE);
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let hash = digest(&SHA256, json.as_bytes());
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Ok(encode_config(
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&hash,
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match version {
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RoomVersionId::Version1 | RoomVersionId::Version2 | RoomVersionId::Version3 => {
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STANDARD_NO_PAD
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}
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// Room versions higher than version 3 are url safe base64 encoded
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_ => URL_SAFE_NO_PAD,
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},
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))
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}
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/// Hashes and signs an event and adds the hash and signature to objects under the keys `hashes` and
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/// `signatures`, respectively.
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///
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/// If `hashes` and/or `signatures` are already present, the new data will be appended to the
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/// existing data.
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///
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/// # Parameters
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///
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/// * entity_id: The identifier of the entity creating the signature. Generally this means a
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/// homeserver, e.g. "example.com".
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/// * key_pair: A cryptographic key pair used to sign the event.
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/// * object: A JSON object to be hashed and signed according to the Matrix specification.
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///
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/// # Errors
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///
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/// Returns an error if:
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///
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/// * `object` contains a field called `content` that is not a JSON object.
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/// * `object` contains a field called `hashes` that is not a JSON object.
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/// * `object` contains a field called `signatures` that is not a JSON object.
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/// * `object` is missing the `type` field or the field is not a JSON string.
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///
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/// # Examples
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///
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/// ```rust
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/// # use ruma_identifiers::RoomVersionId;
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/// # use ruma_signatures::{hash_and_sign_event, Ed25519KeyPair};
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/// #
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/// const PKCS8: &str = "\
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/// MFMCAQEwBQYDK2VwBCIEINjozvdfbsGEt6DD+7Uf4PiJ/YvTNXV2mIPc/\
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/// tA0T+6toSMDIQDdM+tpNzNWQM9NFpfgr4B9S7LHszOrVRp9NfKmeXS3aQ\
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/// ";
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///
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/// let document = base64::decode_config(&PKCS8, base64::STANDARD_NO_PAD).unwrap();
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///
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/// // Create an Ed25519 key pair.
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/// let key_pair = Ed25519KeyPair::new(
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/// &document,
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/// "1".into(), // The "version" of the key.
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/// ).unwrap();
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///
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/// // Deserialize an event from JSON.
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/// let mut object = serde_json::from_str(
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/// r#"{
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/// "room_id": "!x:domain",
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/// "sender": "@a:domain",
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/// "origin": "domain",
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/// "origin_server_ts": 1000000,
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/// "signatures": {},
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/// "hashes": {},
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/// "type": "X",
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/// "content": {},
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/// "prev_events": [],
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/// "auth_events": [],
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/// "depth": 3,
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/// "unsigned": {
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/// "age_ts": 1000000
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/// }
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/// }"#
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/// ).unwrap();
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///
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/// // Hash and sign the JSON with the key pair.
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/// assert!(hash_and_sign_event("domain", &key_pair, &mut object, &RoomVersionId::Version1).is_ok());
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/// ```
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///
|
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/// This will modify the JSON from the structure shown to a structure like this:
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///
|
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/// ```json
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/// {
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/// "auth_events": [],
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/// "content": {},
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/// "depth": 3,
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/// "hashes": {
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/// "sha256": "5jM4wQpv6lnBo7CLIghJuHdW+s2CMBJPUOGOC89ncos"
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/// },
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/// "origin": "domain",
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/// "origin_server_ts": 1000000,
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/// "prev_events": [],
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/// "room_id": "!x:domain",
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/// "sender": "@a:domain",
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/// "signatures": {
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/// "domain": {
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/// "ed25519:1": "KxwGjPSDEtvnFgU00fwFz+l6d2pJM6XBIaMEn81SXPTRl16AqLAYqfIReFGZlHi5KLjAWbOoMszkwsQma+lYAg"
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/// }
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/// },
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/// "type": "X",
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/// "unsigned": {
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/// "age_ts": 1000000
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/// }
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/// }
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/// ```
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///
|
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/// Notice the addition of `hashes` and `signatures`.
|
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pub fn hash_and_sign_event<K>(
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entity_id: &str,
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key_pair: &K,
|
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object: &mut CanonicalJsonObject,
|
|
version: &RoomVersionId,
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) -> Result<(), Error>
|
|
where
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K: KeyPair,
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{
|
|
let hash = content_hash(object);
|
|
|
|
let hashes_value = object
|
|
.entry("hashes".to_owned())
|
|
.or_insert_with(|| CanonicalJsonValue::Object(BTreeMap::new()));
|
|
|
|
match hashes_value {
|
|
CanonicalJsonValue::Object(hashes) => {
|
|
hashes.insert("sha256".into(), CanonicalJsonValue::String(hash))
|
|
}
|
|
_ => return Err(Error::new("field `hashes` must be a JSON object")),
|
|
};
|
|
|
|
let mut redacted = redact(object, version)?;
|
|
|
|
sign_json(entity_id, key_pair, &mut redacted)?;
|
|
|
|
object.insert("signatures".into(), mem::take(redacted.get_mut("signatures").unwrap()));
|
|
|
|
Ok(())
|
|
}
|
|
|
|
/// Verifies that the signed event contains all the required valid signatures.
|
|
///
|
|
/// Some room versions may require signatures from multiple homeservers, so this function takes a
|
|
/// map from servers to sets of public keys. Signatures are verified for each required homeserver.
|
|
/// All known public keys for a homeserver should be provided. The first one found on the given
|
|
/// event will be used.
|
|
///
|
|
/// If the `Ok` variant is returned by this function, it will contain a `Verified` value which
|
|
/// distinguishes an event with valid signatures and a matching content hash with an event with
|
|
/// only valid signatures. See the documentation for `Verified` for details.
|
|
///
|
|
/// # Parameters
|
|
///
|
|
/// * public_key_map: A map from entity identifiers to a map from key identifiers to public keys.
|
|
/// Generally, entity identifiers are server names—the host/IP/port of a homeserver (e.g.
|
|
/// "example.com") for which a signature must be verified. Key identifiers for each server (e.g.
|
|
/// "ed25519:1") then map to their respective public keys.
|
|
/// * object: The JSON object of the event that was signed.
|
|
/// * version: Room version of the given event
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```rust
|
|
/// # use std::collections::BTreeMap;
|
|
/// # use ruma_identifiers::RoomVersionId;
|
|
/// # use ruma_signatures::verify_event;
|
|
/// # use ruma_signatures::Verified;
|
|
/// #
|
|
/// const PUBLIC_KEY: &str = "XGX0JRS2Af3be3knz2fBiRbApjm2Dh61gXDJA8kcJNI";
|
|
///
|
|
/// // Deserialize an event from JSON.
|
|
/// let object = serde_json::from_str(
|
|
/// r#"{
|
|
/// "auth_events": [],
|
|
/// "content": {},
|
|
/// "depth": 3,
|
|
/// "hashes": {
|
|
/// "sha256": "5jM4wQpv6lnBo7CLIghJuHdW+s2CMBJPUOGOC89ncos"
|
|
/// },
|
|
/// "origin": "domain",
|
|
/// "origin_server_ts": 1000000,
|
|
/// "prev_events": [],
|
|
/// "room_id": "!x:domain",
|
|
/// "sender": "@a:domain",
|
|
/// "signatures": {
|
|
/// "domain": {
|
|
/// "ed25519:1": "KxwGjPSDEtvnFgU00fwFz+l6d2pJM6XBIaMEn81SXPTRl16AqLAYqfIReFGZlHi5KLjAWbOoMszkwsQma+lYAg"
|
|
/// }
|
|
/// },
|
|
/// "type": "X",
|
|
/// "unsigned": {
|
|
/// "age_ts": 1000000
|
|
/// }
|
|
/// }"#
|
|
/// ).unwrap();
|
|
///
|
|
/// // Create the `PublicKeyMap` that will inform `verify_json` which signatures to verify.
|
|
/// let mut public_key_set = BTreeMap::new();
|
|
/// public_key_set.insert("ed25519:1".into(), PUBLIC_KEY.to_string());
|
|
/// let mut public_key_map = BTreeMap::new();
|
|
/// public_key_map.insert("domain".into(), public_key_set);
|
|
///
|
|
/// // Verify at least one signature for each entity in `public_key_map`.
|
|
/// let verification_result = verify_event(&public_key_map, &object, &RoomVersionId::Version6);
|
|
/// assert!(verification_result.is_ok());
|
|
/// assert!(matches!(verification_result.unwrap(), Verified::All));
|
|
/// ```
|
|
pub fn verify_event(
|
|
public_key_map: &PublicKeyMap,
|
|
object: &CanonicalJsonObject,
|
|
version: &RoomVersionId,
|
|
) -> Result<Verified, Error> {
|
|
let redacted = redact(object, version)?;
|
|
|
|
let hash = match object.get("hashes") {
|
|
Some(hashes_value) => match hashes_value {
|
|
CanonicalJsonValue::Object(hashes) => match hashes.get("sha256") {
|
|
Some(hash_value) => match hash_value {
|
|
CanonicalJsonValue::String(hash) => hash,
|
|
_ => return Err(Error::new("sha256 hash must be a JSON string")),
|
|
},
|
|
None => return Err(Error::new("field `hashes` must be a JSON object")),
|
|
},
|
|
_ => return Err(Error::new("event missing sha256 hash")),
|
|
},
|
|
None => return Err(Error::new("field `hashes` must be present")),
|
|
};
|
|
|
|
let signature_map = match object.get("signatures") {
|
|
Some(CanonicalJsonValue::Object(signatures)) => signatures,
|
|
Some(_) => return Err(Error::new("field `signatures` must be a JSON object")),
|
|
None => return Err(Error::new("JSON object must contain a `signatures` field.")),
|
|
};
|
|
|
|
let servers_to_check = servers_to_check_signatures(object, version)?;
|
|
let canonical_json = from_json_str(&canonical_json(&redacted))?;
|
|
|
|
for entity_id in servers_to_check {
|
|
let signature_set = match signature_map.get(entity_id.as_str()) {
|
|
Some(CanonicalJsonValue::Object(set)) => set,
|
|
Some(_) => return Err(Error::new("signatures sets must be JSON objects")),
|
|
None => {
|
|
return Err(Error::new(format!("no signatures found for entity `{}`", entity_id)))
|
|
}
|
|
};
|
|
|
|
let mut maybe_signature = None;
|
|
let mut maybe_public_key = None;
|
|
|
|
let public_keys = public_key_map
|
|
.get(entity_id.as_str())
|
|
.ok_or_else(|| Error::new(format!("missing public keys for server {}", entity_id)))?;
|
|
|
|
for (key_id, public_key) in public_keys {
|
|
// Since only ed25519 is supported right now, we don't actually need to check what the
|
|
// algorithm is. If it split successfully, it's ed25519.
|
|
if split_id(key_id).is_err() {
|
|
break;
|
|
}
|
|
|
|
if let Some(signature) = signature_set.get(key_id) {
|
|
maybe_signature = Some(signature);
|
|
maybe_public_key = Some(public_key);
|
|
|
|
break;
|
|
}
|
|
}
|
|
|
|
let signature = match maybe_signature {
|
|
Some(CanonicalJsonValue::String(signature)) => signature,
|
|
Some(_) => return Err(Error::new("signature must be a string")),
|
|
None => {
|
|
return Err(Error::new("event is not signed with any of the given public keys"))
|
|
}
|
|
};
|
|
|
|
let public_key = match maybe_public_key {
|
|
Some(public_key) => public_key,
|
|
None => {
|
|
return Err(Error::new("event is not signed with any of the given public keys"))
|
|
}
|
|
};
|
|
|
|
let signature_bytes = decode_config(signature, STANDARD_NO_PAD)?;
|
|
|
|
let public_key_bytes = decode_config(&public_key, STANDARD_NO_PAD)?;
|
|
|
|
verify_json_with(&Ed25519Verifier, &public_key_bytes, &signature_bytes, &canonical_json)?;
|
|
}
|
|
|
|
let calculated_hash = content_hash(object);
|
|
|
|
if *hash == calculated_hash {
|
|
Ok(Verified::All)
|
|
} else {
|
|
Ok(Verified::Signatures)
|
|
}
|
|
}
|
|
|
|
/// Internal implementation detail of the canonical JSON algorithm. Allows customization of the
|
|
/// fields that will be removed before serializing.
|
|
fn canonical_json_with_fields_to_remove(object: &CanonicalJsonObject, fields: &[&str]) -> String {
|
|
let mut owned_object = object.clone();
|
|
|
|
for field in fields {
|
|
owned_object.remove(*field);
|
|
}
|
|
|
|
to_canonical_json_string(&owned_object).expect("JSON object serialization to succeed")
|
|
}
|
|
|
|
/// Redacts an event using the rules specified in the Matrix client-server specification.
|
|
///
|
|
/// This is part of the process of signing an event.
|
|
///
|
|
/// Redaction is also suggested when a verifying an event with `verify_event` returns
|
|
/// `Verified::Signatures`. See the documentation for `Verified` for details.
|
|
///
|
|
/// Returns a new JSON object with all applicable fields redacted.
|
|
///
|
|
/// # Parameters
|
|
///
|
|
/// * object: A JSON object to redact.
|
|
///
|
|
/// # Errors
|
|
///
|
|
/// Returns an error if:
|
|
///
|
|
/// * `object` contains a field called `content` that is not a JSON object.
|
|
/// * `object` contains a field called `hashes` that is not a JSON object.
|
|
/// * `object` contains a field called `signatures` that is not a JSON object.
|
|
/// * `object` is missing the `type` field or the field is not a JSON string.
|
|
pub fn redact(
|
|
object: &CanonicalJsonObject,
|
|
version: &RoomVersionId,
|
|
) -> Result<CanonicalJsonObject, Error> {
|
|
let mut event = object.clone();
|
|
|
|
let event_type_value = match event.get("type") {
|
|
Some(event_type_value) => event_type_value,
|
|
None => return Err(Error::new("field `type` in JSON value must be present")),
|
|
};
|
|
|
|
let allowed_content_keys = match event_type_value {
|
|
CanonicalJsonValue::String(event_type) => allowed_content_keys_for(event_type, version),
|
|
_ => return Err(Error::new("field `type` in JSON value must be a JSON string")),
|
|
};
|
|
|
|
if let Some(content_value) = event.get_mut("content") {
|
|
let content = match content_value {
|
|
CanonicalJsonValue::Object(map) => map,
|
|
_ => return Err(Error::new("field `content` in JSON value must be a JSON object")),
|
|
};
|
|
|
|
let mut old_content = mem::replace(content, BTreeMap::new());
|
|
|
|
for &key in allowed_content_keys {
|
|
if let Some(value) = old_content.remove(key) {
|
|
content.insert(key.to_owned(), value);
|
|
}
|
|
}
|
|
}
|
|
|
|
let mut old_event = mem::replace(&mut event, BTreeMap::new());
|
|
|
|
for &key in ALLOWED_KEYS {
|
|
if let Some(value) = old_event.remove(key) {
|
|
event.insert(key.to_owned(), value);
|
|
}
|
|
}
|
|
|
|
Ok(event)
|
|
}
|
|
|
|
/// Extracts the server names to check signatures for given event. It will return the sender's
|
|
/// server (unless it's a third party invite) and the event id server (on v1 and v2 room versions)
|
|
fn servers_to_check_signatures(
|
|
object: &CanonicalJsonObject,
|
|
version: &RoomVersionId,
|
|
) -> Result<BTreeSet<ServerNameBox>, Error> {
|
|
let mut servers_to_check = BTreeSet::new();
|
|
|
|
if !is_third_party_invite(object)? {
|
|
match object.get("sender") {
|
|
Some(CanonicalJsonValue::String(raw_sender)) => {
|
|
let user_id = UserId::from_str(raw_sender)
|
|
.map_err(|_| Error::new("could not parse user id"))?;
|
|
|
|
servers_to_check.insert(user_id.server_name().to_owned());
|
|
}
|
|
_ => return Err(Error::new("field `sender` must be a JSON string")),
|
|
};
|
|
}
|
|
|
|
match version {
|
|
RoomVersionId::Version1 | RoomVersionId::Version2 => match object.get("event_id") {
|
|
Some(CanonicalJsonValue::String(raw_event_id)) => {
|
|
let event_id = EventId::from_str(raw_event_id)
|
|
.map_err(|_| Error::new("could not parse event id"))?;
|
|
|
|
let server_name = event_id
|
|
.server_name()
|
|
.ok_or_else(|| {
|
|
Error::new("Event id should have a server name for the given room version")
|
|
})?
|
|
.to_owned();
|
|
|
|
servers_to_check.insert(server_name);
|
|
}
|
|
_ => {
|
|
return Err(Error::new(
|
|
"Expected to find a string `event_id` for the given room version",
|
|
))
|
|
}
|
|
},
|
|
_ => (),
|
|
}
|
|
|
|
Ok(servers_to_check)
|
|
}
|
|
|
|
/// Checks if `object` contains an event of type `m.room.third_party_invite`
|
|
fn is_third_party_invite(object: &CanonicalJsonObject) -> Result<bool, Error> {
|
|
match object.get("type") {
|
|
Some(CanonicalJsonValue::String(raw_type)) => Ok(raw_type == "m.room.third_party_invite"),
|
|
_ => Err(Error::new("field `type` must be a JSON string")),
|
|
}
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod tests {
|
|
use std::{
|
|
collections::BTreeMap,
|
|
convert::{TryFrom, TryInto},
|
|
};
|
|
|
|
use base64::{encode_config, STANDARD_NO_PAD};
|
|
use ruma_identifiers::{RoomVersionId, ServerSigningKeyId, SigningKeyAlgorithm};
|
|
use ruma_serde::CanonicalJsonValue;
|
|
use serde_json::json;
|
|
|
|
use super::canonical_json;
|
|
use crate::{sign_json, verify_event, Ed25519KeyPair, PublicKeyMap, PublicKeySet, Verified};
|
|
|
|
#[test]
|
|
fn canonical_json_complex() {
|
|
let data = json!({
|
|
"auth": {
|
|
"success": true,
|
|
"mxid": "@john.doe:example.com",
|
|
"profile": {
|
|
"display_name": "John Doe",
|
|
"three_pids": [
|
|
{
|
|
"medium": "email",
|
|
"address": "john.doe@example.org"
|
|
},
|
|
{
|
|
"medium": "msisdn",
|
|
"address": "123456789"
|
|
}
|
|
]
|
|
}
|
|
}
|
|
});
|
|
|
|
let canonical = r#"{"auth":{"mxid":"@john.doe:example.com","profile":{"display_name":"John Doe","three_pids":[{"address":"john.doe@example.org","medium":"email"},{"address":"123456789","medium":"msisdn"}]},"success":true}}"#;
|
|
|
|
let object = match CanonicalJsonValue::try_from(data).unwrap() {
|
|
CanonicalJsonValue::Object(obj) => obj,
|
|
_ => unreachable!(),
|
|
};
|
|
|
|
assert_eq!(canonical_json(&object), canonical);
|
|
}
|
|
|
|
#[test]
|
|
fn verify_event_does_not_check_signatures_for_third_party_invites() {
|
|
let signed_event = serde_json::from_str(
|
|
r#"{
|
|
"auth_events": [],
|
|
"content": {},
|
|
"depth": 3,
|
|
"hashes": {
|
|
"sha256": "5jM4wQpv6lnBo7CLIghJuHdW+s2CMBJPUOGOC89ncos"
|
|
},
|
|
"origin": "domain",
|
|
"origin_server_ts": 1000000,
|
|
"prev_events": [],
|
|
"room_id": "!x:domain",
|
|
"sender": "@a:domain",
|
|
"signatures": {
|
|
"domain": {
|
|
"ed25519:1": "KxwGjPSDEtvnFgU00fwFz+l6d2pJM6XBIaMEn81SXPTRl16AqLAYqfIReFGZlHi5KLjAWbOoMszkwsQma+lYAg"
|
|
}
|
|
},
|
|
"type": "m.room.third_party_invite",
|
|
"unsigned": {
|
|
"age_ts": 1000000
|
|
}
|
|
}"#
|
|
).unwrap();
|
|
|
|
let public_key_map = BTreeMap::new();
|
|
let verification_result =
|
|
verify_event(&public_key_map, &signed_event, &RoomVersionId::Version6);
|
|
|
|
assert!(verification_result.is_ok());
|
|
let verification = verification_result.unwrap();
|
|
assert!(matches!(verification, Verified::Signatures));
|
|
}
|
|
|
|
#[test]
|
|
fn verify_event_check_signatures_for_both_sender_and_event_id() {
|
|
let key_pair_sender = generate_key_pair();
|
|
let key_pair_event = generate_key_pair();
|
|
let mut signed_event = serde_json::from_str(
|
|
r#"{
|
|
"event_id": "$event_id:domain-event",
|
|
"auth_events": [],
|
|
"content": {},
|
|
"depth": 3,
|
|
"hashes": {
|
|
"sha256": "5jM4wQpv6lnBo7CLIghJuHdW+s2CMBJPUOGOC89ncos"
|
|
},
|
|
"origin": "domain",
|
|
"origin_server_ts": 1000000,
|
|
"prev_events": [],
|
|
"room_id": "!x:domain",
|
|
"sender": "@name:domain-sender",
|
|
"type": "X",
|
|
"unsigned": {
|
|
"age_ts": 1000000
|
|
}
|
|
}"#,
|
|
)
|
|
.unwrap();
|
|
sign_json("domain-sender", &key_pair_sender, &mut signed_event).unwrap();
|
|
sign_json("domain-event", &key_pair_event, &mut signed_event).unwrap();
|
|
|
|
let mut public_key_map = BTreeMap::new();
|
|
add_key_to_map(&mut public_key_map, "domain-sender", &key_pair_sender);
|
|
add_key_to_map(&mut public_key_map, "domain-event", &key_pair_event);
|
|
|
|
let verification_result =
|
|
verify_event(&public_key_map, &signed_event, &RoomVersionId::Version1);
|
|
|
|
assert!(verification_result.is_ok());
|
|
let verification = verification_result.unwrap();
|
|
assert!(matches!(verification, Verified::Signatures));
|
|
}
|
|
|
|
#[test]
|
|
fn verification_fails_if_required_keys_are_not_given() {
|
|
let key_pair_sender = generate_key_pair();
|
|
|
|
let mut signed_event = serde_json::from_str(
|
|
r#"{
|
|
"auth_events": [],
|
|
"content": {},
|
|
"depth": 3,
|
|
"hashes": {
|
|
"sha256": "5jM4wQpv6lnBo7CLIghJuHdW+s2CMBJPUOGOC89ncos"
|
|
},
|
|
"origin": "domain",
|
|
"origin_server_ts": 1000000,
|
|
"prev_events": [],
|
|
"room_id": "!x:domain",
|
|
"sender": "@name:domain-sender",
|
|
"type": "X",
|
|
"unsigned": {
|
|
"age_ts": 1000000
|
|
}
|
|
}"#,
|
|
)
|
|
.unwrap();
|
|
sign_json("domain-sender", &key_pair_sender, &mut signed_event).unwrap();
|
|
|
|
// Verify with an empty public key map should fail due to missing public keys
|
|
let public_key_map = BTreeMap::new();
|
|
let verification_result =
|
|
verify_event(&public_key_map, &signed_event, &RoomVersionId::Version6);
|
|
|
|
assert!(verification_result.is_err());
|
|
let error_msg = verification_result.err().unwrap().message;
|
|
assert!(error_msg.contains("missing public keys for server"));
|
|
}
|
|
|
|
#[test]
|
|
fn verify_event_fails_if_public_key_is_invalid() {
|
|
let key_pair_sender = generate_key_pair();
|
|
|
|
let mut signed_event = serde_json::from_str(
|
|
r#"{
|
|
"auth_events": [],
|
|
"content": {},
|
|
"depth": 3,
|
|
"hashes": {
|
|
"sha256": "5jM4wQpv6lnBo7CLIghJuHdW+s2CMBJPUOGOC89ncos"
|
|
},
|
|
"origin": "domain",
|
|
"origin_server_ts": 1000000,
|
|
"prev_events": [],
|
|
"room_id": "!x:domain",
|
|
"sender": "@name:domain-sender",
|
|
"type": "X",
|
|
"unsigned": {
|
|
"age_ts": 1000000
|
|
}
|
|
}"#,
|
|
)
|
|
.unwrap();
|
|
sign_json("domain-sender", &key_pair_sender, &mut signed_event).unwrap();
|
|
|
|
let mut public_key_map = PublicKeyMap::new();
|
|
let mut sender_key_map = PublicKeySet::new();
|
|
let newly_generated_key_pair = generate_key_pair();
|
|
let encoded_public_key =
|
|
encode_config(newly_generated_key_pair.public_key(), STANDARD_NO_PAD);
|
|
let version = ServerSigningKeyId::from_parts(
|
|
SigningKeyAlgorithm::Ed25519,
|
|
key_pair_sender.version().try_into().unwrap(),
|
|
);
|
|
sender_key_map.insert(version.to_string(), encoded_public_key);
|
|
public_key_map.insert("domain-sender".to_string(), sender_key_map);
|
|
|
|
let verification_result =
|
|
verify_event(&public_key_map, &signed_event, &RoomVersionId::Version6);
|
|
|
|
assert!(verification_result.is_err());
|
|
let error_msg = verification_result.err().unwrap().message;
|
|
assert!(error_msg.contains("signature verification failed"));
|
|
}
|
|
|
|
fn generate_key_pair() -> Ed25519KeyPair {
|
|
let key_content = Ed25519KeyPair::generate().unwrap();
|
|
Ed25519KeyPair::new(&key_content, "1".to_string()).unwrap()
|
|
}
|
|
|
|
fn add_key_to_map(public_key_map: &mut PublicKeyMap, name: &str, pair: &Ed25519KeyPair) {
|
|
let mut sender_key_map = PublicKeySet::new();
|
|
let encoded_public_key = encode_config(pair.public_key(), STANDARD_NO_PAD);
|
|
let version = ServerSigningKeyId::from_parts(
|
|
SigningKeyAlgorithm::Ed25519,
|
|
pair.version().try_into().unwrap(),
|
|
);
|
|
|
|
sender_key_map.insert(version.to_string(), encoded_public_key);
|
|
|
|
public_key_map.insert(name.to_string(), sender_key_map);
|
|
}
|
|
}
|