troll-patrol/src/tests/reports/positive_reports.rs

#![allow(non_snake_case)]

use crate::{bridge_verification_info::BridgeVerificationInfo, *};
use lox_library::{
    bridge_table::{self, BridgeLine},
    cred::Lox,
    proto::*,
    scalar_u32, BridgeAuth, BridgeDb,
};

use base64::{engine::general_purpose, Engine as _};
use curve25519_dalek::{ristretto::RistrettoBasepointTable, Scalar};
use rand::RngCore;
use std::collections::HashSet;

struct TestHarness {
    bdb: BridgeDb,
    pub ba: BridgeAuth,
}

impl TestHarness {
    fn new() -> Self {
        TestHarness::new_buckets(5, 5)
    }

    fn new_buckets(num_buckets: u16, hot_spare: u16) -> Self {
        // Create a BridegDb
        let mut bdb = BridgeDb::new();
        // Create a BridgeAuth
        let mut ba = BridgeAuth::new(bdb.pubkey);

        // Make 3 x num_buckets open invitation bridges, in sets of 3
        for _ in 0..num_buckets {
            let bucket = [random(), random(), random()];
            let _ = ba.add_openinv_bridges(bucket, &mut bdb);
        }
        // Add hot_spare more hot spare buckets
        for _ in 0..hot_spare {
            let bucket = [random(), random(), random()];
            let _ = ba.add_spare_bucket(bucket, &mut bdb);
        }
        // Create the encrypted bridge table
        ba.enc_bridge_table();

        Self { bdb, ba }
    }

    fn advance_days(&mut self, days: u16) {
        self.ba.advance_days(days);
    }

    fn get_new_credential(&mut self) -> Lox {
        let inv = self.bdb.invite().unwrap();
        let (req, state) = open_invite::request(&inv);
        let resp = self.ba.handle_open_invite(req).unwrap();
        let (cred, _bridgeline) =
            open_invite::handle_response(state, resp, &self.ba.lox_pub).unwrap();
        cred
    }

    fn level_up(&mut self, cred: &Lox) -> Lox {
        let current_level = scalar_u32(&cred.trust_level).unwrap();
        if current_level == 0 {
            self.advance_days(trust_promotion::UNTRUSTED_INTERVAL.try_into().unwrap());
            let (promreq, promstate) =
                trust_promotion::request(cred, &self.ba.lox_pub, self.ba.today()).unwrap();
            let promresp = self.ba.handle_trust_promotion(promreq).unwrap();
            let migcred = trust_promotion::handle_response(promstate, promresp).unwrap();
            let (migreq, migstate) =
                migration::request(cred, &migcred, &self.ba.lox_pub, &self.ba.migration_pub)
                    .unwrap();
            let migresp = self.ba.handle_migration(migreq).unwrap();
            let new_cred = migration::handle_response(migstate, migresp, &self.ba.lox_pub).unwrap();
            new_cred
        } else {
            self.advance_days(
                level_up::LEVEL_INTERVAL[usize::try_from(current_level).unwrap()]
                    .try_into()
                    .unwrap(),
            );
            let (id, key) = bridge_table::from_scalar(cred.bucket).unwrap();
            let encbuckets = self.ba.enc_bridge_table();
            let bucket =
                bridge_table::BridgeTable::decrypt_bucket(id, &key, encbuckets.get(&id).unwrap())
                    .unwrap();
            let reachcred = bucket.1.unwrap();
            let (lvreq, lvstate) = level_up::request(
                cred,
                &reachcred,
                &self.ba.lox_pub,
                &self.ba.reachability_pub,
                self.ba.today(),
            )
            .unwrap();
            let lvresp = self.ba.handle_level_up(lvreq).unwrap();
            let new_cred = level_up::handle_response(lvstate, lvresp, &self.ba.lox_pub).unwrap();
            new_cred
        }
    }

    fn get_bucket(&mut self, cred: &Lox) -> [BridgeLine; bridge_table::MAX_BRIDGES_PER_BUCKET] {
        let (id, key) = bridge_table::from_scalar(cred.bucket).unwrap();
        let encbuckets = self.ba.enc_bridge_table();
        let bucket =
            bridge_table::BridgeTable::decrypt_bucket(id, &key, encbuckets.get(&id).unwrap())
                .unwrap();
        bucket.0
    }
}

pub fn random() -> BridgeLine {
    let mut rng = rand::thread_rng();
    let mut res: BridgeLine = BridgeLine::default();
    // Pick a random 4-byte address
    let mut addr: [u8; 4] = [0; 4];
    rng.fill_bytes(&mut addr);
    // If the leading byte is 224 or more, that's not a valid IPv4
    // address.  Choose an IPv6 address instead (but don't worry too
    // much about it being well formed).
    if addr[0] >= 224 {
        rng.fill_bytes(&mut res.addr);
    } else {
        // Store an IPv4 address as a v4-mapped IPv6 address
        res.addr[10] = 255;
        res.addr[11] = 255;
        res.addr[12..16].copy_from_slice(&addr);
    };
    let ports: [u16; 4] = [443, 4433, 8080, 43079];
    let portidx = (rng.next_u32() % 4) as usize;
    res.port = ports[portidx];
    res.uid_fingerprint = rng.next_u64();
    rng.fill_bytes(&mut res.fingerprint);
    let mut cert: [u8; 52] = [0; 52];
    rng.fill_bytes(&mut cert);
    let infostr: String = format!(
        "obfs4 cert={}, iat-mode=0",
        general_purpose::STANDARD_NO_PAD.encode(cert)
    );
    res.info[..infostr.len()].copy_from_slice(infostr.as_bytes());
    res
}

#[test]
fn test_positive_reports() {
    let mut th = TestHarness::new();

    // Get new level 3 credential
    let cred = th.get_new_credential();
    let cred = th.level_up(&cred);
    let cred = th.level_up(&cred);
    let cred = th.level_up(&cred);

    let bridges = th.get_bucket(&cred);

    // Create BridgeVerificationInfo for each bridge
    let mut buckets = HashSet::<Scalar>::new();
    buckets.insert(cred.bucket);
    let bridge_info_1 = BridgeVerificationInfo {
        bridge_line: bridges[0],
        buckets: buckets.clone(),
        pubkey: None,
    };
    let bridge_info_2 = BridgeVerificationInfo {
        bridge_line: bridges[1],
        buckets: buckets.clone(),
        pubkey: None,
    };
    let bridge_info_3 = BridgeVerificationInfo {
        bridge_line: bridges[2],
        buckets: buckets.clone(),
        pubkey: None,
    };

    // Create reports
    let report_1 = PositiveReport::from_lox_credential(
        bridges[0].fingerprint,
        None,
        &cred,
        &th.ba.lox_pub,
        "ru".to_string(),
    )
    .unwrap();
    let report_2 = PositiveReport::from_lox_credential(
        bridges[1].fingerprint,
        None,
        &cred,
        &th.ba.lox_pub,
        "ru".to_string(),
    )
    .unwrap();
    let report_3 = PositiveReport::from_lox_credential(
        bridges[2].fingerprint,
        None,
        &cred,
        &th.ba.lox_pub,
        "ru".to_string(),
    )
    .unwrap();

    // Compute Htable
    let H = lox_library::proto::positive_report::compute_H(report_1.date);
    let Htable = RistrettoBasepointTable::create(&H);

    assert!(report_1.verify(&mut th.ba, &bridge_info_1, &Htable));
    assert!(report_2.verify(&mut th.ba, &bridge_info_2, &Htable));
    assert!(report_3.verify(&mut th.ba, &bridge_info_3, &Htable));

    // Check that user cannot use credential for other bridge

    // Get new credential
    let cred_2 = th.get_new_credential();
    let bridges_2 = th.get_bucket(&cred_2);

    let mut buckets_2 = HashSet::<Scalar>::new();
    buckets_2.insert(cred_2.bucket);
    let bridge_info_4 = BridgeVerificationInfo {
        bridge_line: bridges_2[0],
        buckets: buckets_2.clone(),
        pubkey: None,
    };

    // Use new credential to create positive report even we don't trust it
    let invalid_report_1 = PositiveReport::from_lox_credential(
        bridges_2[0].fingerprint,
        None,
        &cred_2,
        &th.ba.lox_pub,
        "ru".to_string(),
    );

    // Use first credential for bridge from second bucket
    let invalid_report_2 = PositiveReport::from_lox_credential(
        bridges_2[0].fingerprint,
        None,
        &cred,
        &th.ba.lox_pub,
        "ru".to_string(),
    );

    // Use second credential for bridge from first bucket
    let invalid_report_3 = PositiveReport::from_lox_credential(
        bridges[0].fingerprint,
        None,
        &cred_2,
        &th.ba.lox_pub,
        "ru".to_string(),
    );

    // Check that all of these fail
    assert!(invalid_report_1.is_err());
    assert!(!invalid_report_2
        .unwrap()
        .verify(&mut th.ba, &bridge_info_4, &Htable));
    assert!(invalid_report_3.is_err());

    // Check that deserialization fails under invalid conditions

    // Date in the future
    let mut invalid_report_4 = PositiveReport::from_lox_credential(
        bridges[0].fingerprint,
        None,
        &cred,
        &th.ba.lox_pub,
        "ru".to_string(),
    )
    .unwrap()
    .to_serializable_report();
    invalid_report_4.date = invalid_report_4.date + 2;

    // Invalid country code
    let invalid_report_5 = PositiveReport::from_lox_credential(
        bridges[0].fingerprint,
        None,
        &cred,
        &th.ba.lox_pub,
        "xx".to_string(),
    )
    .unwrap()
    .to_serializable_report();

    assert!(invalid_report_4.to_report().is_err());
    assert!(invalid_report_5.to_report().is_err());

    // Test storing to-be-processed positive reports to database

    // Create reports
    let report_1 = PositiveReport::from_lox_credential(
        bridges[0].fingerprint,
        None,
        &cred,
        &th.ba.lox_pub,
        "ru".to_string(),
    )
    .unwrap();
    let report_2 = PositiveReport::from_lox_credential(
        bridges[0].fingerprint,
        None,
        &cred,
        &th.ba.lox_pub,
        "ru".to_string(),
    )
    .unwrap();
    let report_3 = PositiveReport::from_lox_credential(
        bridges[1].fingerprint,
        None,
        &cred,
        &th.ba.lox_pub,
        "ru".to_string(),
    )
    .unwrap();

    // Open test database
    let db: Db = sled::open("test_db_pr").unwrap();

    // Delete all data in test DB
    db.clear().unwrap();
    assert!(!db.contains_key("prs-to-process").unwrap());

    let map_key_1 = format!(
        "{}_{}_{}",
        array_bytes::bytes2hex("", report_1.fingerprint),
        &report_1.country,
        &report_1.date
    );
    let map_key_2 = format!(
        "{}_{}_{}",
        array_bytes::bytes2hex("", report_3.fingerprint),
        &report_3.country,
        &report_3.date
    );

    save_positive_report_to_process(&db, report_1);
    let prs_to_process: BTreeMap<String, Vec<SerializablePositiveReport>> =
        bincode::deserialize(&db.get("prs-to-process").unwrap().unwrap()).unwrap();
    let positive_reports = prs_to_process.get(&map_key_1).unwrap();
    assert_eq!(positive_reports.len(), 1);
    assert!(!prs_to_process.contains_key(&map_key_2));

    save_positive_report_to_process(&db, report_2);
    let prs_to_process: BTreeMap<String, Vec<SerializablePositiveReport>> =
        bincode::deserialize(&db.get("prs-to-process").unwrap().unwrap()).unwrap();
    let positive_reports = prs_to_process.get(&map_key_1).unwrap();
    assert_eq!(positive_reports.len(), 2);
    assert!(!prs_to_process.contains_key(&map_key_2));

    save_positive_report_to_process(&db, report_3);
    let prs_to_process: BTreeMap<String, Vec<SerializablePositiveReport>> =
        bincode::deserialize(&db.get("prs-to-process").unwrap().unwrap()).unwrap();
    // Check that this has not changed
    let positive_reports = prs_to_process.get(&map_key_1).unwrap();
    assert_eq!(positive_reports.len(), 2);
    // New report added to its own collection
    let positive_reports = prs_to_process.get(&map_key_2).unwrap();
    assert_eq!(positive_reports.len(), 1);
}