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libbolt/src/channels.rs

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/*
* Implement for Bolt protocols:
* - initializing channel state and generating cust/merch wallets
* - establish protocol
* - pay protocol
* - channel close algorithms (WIP)
*/
extern crate pairing;
extern crate rand;
use super::*;
use pairing::{Engine, CurveProjective};
use pairing::bls12_381::{Bls12};
use ff::PrimeField;
use cl::{BlindKeyPair, KeyPair, Signature, PublicParams, setup};
use ped92::{CSParams, Commitment, CSMultiParams, CommitmentProof};
use util::{hash_pubkey_to_fr, convert_int_to_fr, hash_to_fr, RevokedMessage, hash_to_slice};
use rand::Rng;
use std::collections::HashMap;
use std::fmt::Display;
use serde::{Serialize, Deserialize};
use std::ptr::hash;
use nizk::{NIZKPublicParams, NIZKProof};
use wallet::Wallet;
use std::error::Error;
use std::fmt;
#[derive(Debug)]
pub struct BoltError {
details: String
}
pub type ResultBoltSig<E> = Result<E, BoltError>;
impl BoltError {
fn new(msg: &str) -> BoltError {
BoltError{details: msg.to_string()}
}
}
impl fmt::Display for BoltError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f,"{}",self.details)
}
}
impl Error for BoltError {
fn description(&self) -> &str {
&self.details
}
}
#[derive(Clone, Serialize, Deserialize)]
pub struct PubKeyMap {
pub wpk: secp256k1::PublicKey,
pub revoke_token: Option<secp256k1::Signature>
}
#[derive(Clone, Serialize, Deserialize)]
#[serde(bound(serialize = "<E as ff::ScalarEngine>::Fr: serde::Serialize, \
<E as pairing::Engine>::G1: serde::Serialize, \
<E as pairing::Engine>::G2: serde::Serialize"
))]
#[serde(bound(deserialize = "<E as ff::ScalarEngine>::Fr: serde::Deserialize<'de>, \
<E as pairing::Engine>::G1: serde::Deserialize<'de>, \
<E as pairing::Engine>::G2: serde::Deserialize<'de>"
))]
pub struct ChannelParams<E: Engine> {
pub pub_params: NIZKPublicParams<E>,
l: usize, // messages for commitment
extra_verify: bool // extra verification for certain points in the establish/pay protocol
}
#[derive(Clone, Serialize, Deserialize)]
#[serde(bound(serialize = "<E as ff::ScalarEngine>::Fr: serde::Serialize, \
<E as pairing::Engine>::G1: serde::Serialize, \
<E as pairing::Engine>::G2: serde::Serialize"
))]
#[serde(bound(deserialize = "<E as ff::ScalarEngine>::Fr: serde::Deserialize<'de>, \
<E as pairing::Engine>::G1: serde::Deserialize<'de>, \
<E as pairing::Engine>::G2: serde::Deserialize<'de>"
))]
pub struct ChannelState<E: Engine> {
R: i32,
tx_fee: i32,
pub cp: Option<ChannelParams<E>>,
pub name: String,
pub pay_init: bool,
pub channel_established: bool,
pub third_party: bool
}
#[derive(Clone, Serialize, Deserialize)]
#[serde(bound(serialize = "<E as ff::ScalarEngine>::Fr: serde::Serialize, \
<E as pairing::Engine>::G1: serde::Serialize, \
<E as pairing::Engine>::G2: serde::Serialize"
))]
#[serde(bound(deserialize = "<E as ff::ScalarEngine>::Fr: serde::Deserialize<'de>, \
<E as pairing::Engine>::G1: serde::Deserialize<'de>, \
<E as pairing::Engine>::G2: serde::Deserialize<'de>"
))]
pub struct ChannelToken<E: Engine> {
pub pk_c: Option<secp256k1::PublicKey>, // pk_c
pub pk_m: secp256k1::PublicKey, // pk_m
pub cl_pk_m: cl::PublicKey<E>, // PK_m (used for verifying blind signatures)
pub mpk: cl::PublicParams<E>, // mpk for PK_m
pub comParams: CSMultiParams<E>,
}
impl<E: Engine> ChannelToken<E> {
pub fn set_customer_pk(&mut self, pk_c: &secp256k1::PublicKey) {
self.pk_c = Some(pk_c.clone());
}
pub fn is_init(&self) -> bool {
return !self.pk_c.is_none();
}
pub fn compute_id(&self) -> [u8; 32]
where <E as pairing::Engine>::G1: serde::Serialize,
<E as pairing::Engine>::G2: serde::Serialize,
<E as ff::ScalarEngine>::Fr: serde::Serialize
{
let mut input = Vec::new();
if !self.pk_c.is_none() {
let ser_pkc = self.pk_c.unwrap().serialize_uncompressed();
input.extend_from_slice(&ser_pkc);
}
let ser_pk_m = self.pk_m.serialize_uncompressed();
let ser_cl_pk_m = serde_json::to_vec(&self.cl_pk_m).unwrap();
let ser_mpk = serde_json::to_vec(&self.mpk).unwrap();
let ser_comParams = serde_json::to_vec(&self.comParams).unwrap();
input.extend_from_slice(&ser_pk_m);
input.extend(&ser_cl_pk_m);
input.extend(&ser_mpk);
return hash_to_slice(&input);
}
}
// add methods to check if channel token is initialized
// (only if
///
/// Channel state for generating/loading channel parameters and generating keypairs
///
impl<E: Engine> ChannelState<E> {
pub fn new(name: String, third_party_support: bool) -> ChannelState<E> {
ChannelState {
R: 0,
tx_fee: 0,
cp: None,
name: name.to_string(),
pay_init: false,
channel_established: false,
third_party: third_party_support
}
}
pub fn init() {
sodiumoxide::init();
}
///
/// setup - generate public parameters for bidirectional payment channels
///
pub fn setup<R: Rng>(&mut self, csprng: &mut R) {
let l = 5;
let pubParams = NIZKPublicParams::<E>::setup(csprng, l);
let cp = ChannelParams { pub_params: pubParams, l: l, extra_verify: true };
self.cp = Some(cp);
}
///
/// keygen - takes as input public parameters and generates a digital signature keypair
///
pub fn keygen<R: Rng>(&mut self, csprng: &mut R, id: String) -> cl::BlindKeyPair<E> {
let cp = self.cp.as_ref();
let keypair = BlindKeyPair::<E>::generate(csprng, &cp.unwrap().pub_params.mpk, cp.unwrap().l);
println!("Generating keypair for '{}'", id);
// print the keypair as well
return keypair;
}
pub fn load_params(&mut self, cp: &ChannelParams<E>) {
// load external params
}
pub fn set_channel_fee(&mut self, fee: i32) {
self.tx_fee = fee;
}
pub fn get_channel_fee(&self) -> i32 {
return self.tx_fee as i32;
}
}
#[derive(Copy, Clone, Serialize, Deserialize)]
struct WalletKeyPair {
pub wpk: secp256k1::PublicKey,
pub wsk: secp256k1::SecretKey
}
///
/// Customer wallet consists of a keypair (NEW)
///
#[derive(Clone, Serialize, Deserialize)]
#[serde(bound(serialize = "<E as ff::ScalarEngine>::Fr: serde::Serialize, \
<E as pairing::Engine>::G1: serde::Serialize, \
<E as pairing::Engine>::G2: serde::Serialize"
))]
#[serde(bound(deserialize = "<E as ff::ScalarEngine>::Fr: serde::Deserialize<'de>, \
<E as pairing::Engine>::G1: serde::Deserialize<'de>, \
<E as pairing::Engine>::G2: serde::Deserialize<'de>"
))]
pub struct CustomerState<E: Engine> {
pub name: String,
pub pk_c: secp256k1::PublicKey,
sk_c: secp256k1::SecretKey,
pub cust_balance: i32, //
pub merch_balance: i32,
pub wpk: secp256k1::PublicKey, // keypair bound to the wallet
wsk: secp256k1::SecretKey,
old_kp: Option<WalletKeyPair>, // old wallet key pair
t: E::Fr, // randomness used to form the commitment
wallet: Wallet<E>, // vector of field elements that represent wallet
pub w_com: Commitment<E>, // commitment to the current state of the wallet
index: i32,
close_tokens: HashMap<i32, Signature<E>>,
pay_tokens: HashMap<i32, Signature<E>>
}
impl<E: Engine> CustomerState<E> {
pub fn new<R: Rng>(csprng: &mut R, channel: &ChannelState<E>, channel_token: &mut ChannelToken<E>, cust_bal: i32, merch_bal: i32, name: String) -> Self {
let mut kp = secp256k1::Secp256k1::new();
kp.randomize(csprng);
// generate the keypair for the channel
let (sk_c, pk_c) = kp.generate_keypair(csprng);
// generate the keypair for the initial wallet
let (wsk, wpk) = kp.generate_keypair(csprng);
// hash the wallet pub key
let wpk_h = hash_pubkey_to_fr::<E>(&wpk);
// hash the channel pub key
let pk_h = hash_pubkey_to_fr::<E>(&pk_c);
// randomness for commitment
let t = E::Fr::rand(csprng);
// initialize wallet vector
let wallet = Wallet { pkc: pk_h, wpk: wpk_h, bc: cust_bal, bm: merch_bal, close: None };
let w_com = channel_token.comParams.commit(&wallet.as_fr_vec(), &t);
channel_token.set_customer_pk(&pk_c);
assert!(channel_token.is_init());
let ct_db= HashMap::new();
let pt_db= HashMap::new();
return CustomerState {
name: name,
pk_c: pk_c,
sk_c: sk_c,
cust_balance: cust_bal,
merch_balance: merch_bal,
wpk: wpk,
wsk: wsk,
old_kp: None,
t: t,
w_com: w_com,
wallet: wallet,
index: 0,
close_tokens: ct_db,
pay_tokens: pt_db
}
}
pub fn get_wallet(&self) -> Wallet<E> {
return self.wallet.clone();
}
pub fn get_close_token(&self) -> cl::Signature<E> {
let index = self.index;
let close_token = self.close_tokens.get(&index).unwrap();
// rerandomize first
return close_token.clone();
}
// generate nizk proof of knowledge of commitment opening
pub fn generate_proof<R: Rng>(&self, csprng: &mut R, channel_token: &ChannelToken<E>) -> CommitmentProof<E> {
// generate proof and do a partial reveal of pkc and bc/bm (init balances)
return CommitmentProof::<E>::new(csprng, &channel_token.comParams, &self.w_com.c, &self.wallet.as_fr_vec(), &self.t, &vec![1, 3, 4]);
}
pub fn verify_close_token(&mut self, channel: &ChannelState<E>, close_token: &Signature<E>) -> bool {
// add a prefix to the wallet for close-message
let close_wallet = self.wallet.with_close(String::from("close"));
let cp = channel.cp.as_ref().unwrap();
let mpk = cp.pub_params.mpk.clone();
//println!("verify_close_token - Wallet: {}", &self.wallet);
let is_close_valid = cp.pub_params.keypair.verify(&mpk, &close_wallet, &self.t, &close_token);
if is_close_valid {
//println!("verify_close_token - Blinded close token is valid!!");
let pk = cp.pub_params.keypair.get_public_key(&mpk);
let unblind_close_token = cp.pub_params.keypair.unblind(&self.t, &close_token);
let is_valid = pk.verify(&mpk, &close_wallet, &unblind_close_token);
if is_valid {
// record the unblinded close token
self.close_tokens.insert( self.index, unblind_close_token);
}
return is_valid;
}
//println!("Customer - Verification failed for close token!");
return false;
}
pub fn verify_pay_token(&mut self, channel: &ChannelState<E>, pay_token: &Signature<E>) -> bool {
// unblind and verify signature
let cp = channel.cp.as_ref().unwrap();
let mpk = cp.pub_params.mpk.clone();
// we don't want to include "close" prefix here (even if it is set)
let wallet = self.wallet.without_close();
//println!("verify_pay_token - Wallet: {}", &self.wallet);
let is_pay_valid = cp.pub_params.keypair.verify(&mpk, &wallet, &self.t, &pay_token);
if is_pay_valid {
//println!("verify_pay_token - Blinded pay token is valid!!");
let unblind_pay_token = cp.pub_params.keypair.unblind(&self.t, &pay_token);
let pk = cp.pub_params.keypair.get_public_key(&mpk);
let is_valid = pk.verify(&mpk, &wallet, &unblind_pay_token);
if is_valid {
self.pay_tokens.insert(self.index, unblind_pay_token);
}
return is_valid;
}
//println!("Customer - Verification failed for pay token!");
return false;
}
pub fn has_tokens(&self) -> bool {
let index = self.index;
let is_ct = self.close_tokens.get(&index).is_some();
let is_pt = self.pay_tokens.get(&index).is_some();
return is_ct && is_pt;
}
// for channel pay
pub fn generate_payment<R: Rng>(&self, csprng: &mut R, channel: &ChannelState<E>, amount: i32) -> (NIZKProof<E>, Commitment<E>, secp256k1::PublicKey, CustomerState<E>) {
// 1 - chooose new wpk/wsk pair
let mut kp = secp256k1::Secp256k1::new();
kp.randomize(csprng);
let (new_wsk, new_wpk) = kp.generate_keypair(csprng);
let wpk_h = hash_pubkey_to_fr::<E>(&new_wpk);
// 2 - form new wallet and commitment
let new_cust_bal= self.cust_balance - amount;
let new_merch_bal = self.merch_balance + amount;
let new_t = E::Fr::rand(csprng);
//println!("old wallet close => {}", self.wallet.close.unwrap());
let cp = channel.cp.as_ref().unwrap();
let old_wallet = Wallet { pkc: self.wallet.pkc.clone(), wpk: self.wallet.wpk.clone(), bc: self.cust_balance, bm: self.merch_balance, close: None };
let new_wallet = Wallet { pkc: self.wallet.pkc.clone(), wpk: wpk_h, bc: new_cust_bal, bm: new_merch_bal, close: Some(self.wallet.close.unwrap()) };
let new_wcom = cp.pub_params.comParams.commit(&new_wallet.as_fr_vec(), &new_t);
// 3 - generate new blinded and randomized pay token
let i = self.index;
let prev_pay_token = self.pay_tokens.get(&i).unwrap();
//println!("Found prev pay token: {}", prev_pay_token);
let pay_proof = cp.pub_params.prove(csprng, old_wallet, new_wallet.clone(),
new_wcom.clone(), new_t, &prev_pay_token);
// update internal state after proof has been verified by remote
let new_cw = CustomerState {
name: self.name.clone(),
pk_c: self.pk_c.clone(),
sk_c: self.sk_c.clone(),
cust_balance: new_cust_bal,
merch_balance: new_merch_bal,
wpk: new_wpk,
wsk: new_wsk,
old_kp: Some(WalletKeyPair { wpk: self.wpk.clone(), wsk: self.wsk.clone() }),
t: new_t,
w_com: new_wcom.clone(),
wallet: new_wallet.clone(),
index: self.index, // increment index here
close_tokens: self.close_tokens.clone(),
pay_tokens: self.pay_tokens.clone()
};
return (pay_proof, new_wcom, self.wpk, new_cw);
}
// update the internal state of the customer wallet
pub fn update(&mut self, new_wallet: CustomerState<E>) -> bool {
// update everything except for the wpk/wsk pair
assert!(self.name == new_wallet.name);
self.cust_balance = new_wallet.cust_balance;
self.merch_balance = new_wallet.merch_balance;
self.t = new_wallet.t;
self.old_kp = new_wallet.old_kp;
self.wpk = new_wallet.wpk;
self.wsk = new_wallet.wsk;
self.w_com = new_wallet.w_com;
self.wallet = new_wallet.wallet;
self.index = new_wallet.index;
self.close_tokens = new_wallet.close_tokens;
self.pay_tokens = new_wallet.pay_tokens;
return true;
}
pub fn generate_revoke_token(&mut self, channel: &ChannelState<E>, close_token: &Signature<E>) -> ResultBoltSig<(RevokedMessage, secp256k1::Signature)> {
if self.verify_close_token(channel, close_token) {
let old_wallet = self.old_kp.unwrap();
// proceed with generating the close token
let secp = secp256k1::Secp256k1::new();
let rm = RevokedMessage::new(String::from("revoked"), old_wallet.wpk);
let revoke_msg = secp256k1::Message::from_slice(&rm.hash_to_slice()).unwrap();
// msg = "revoked"|| old wsk (for old wallet)
let revoke_token = secp.sign(&revoke_msg, &old_wallet.wsk);
return Ok((rm, revoke_token));
}
Err(BoltError::new("generate_revoke_token - could not verify the close token."))
}
}
impl<E: Engine> fmt::Display for CustomerState<E> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
let mut content = String::new();
content = format!("name = {}\n", &self.name);
content = format!("{}pk = {}\n", content, &self.pk_c);
content = format!("{}sk = {}\n", content, &self.sk_c);
content = format!("{}cust-bal = {}\n", content, &self.cust_balance);
content = format!("{}merch-bal = {}\n", content, &self.merch_balance);
content = format!("{}wpk = {}\nwsk = {}\n", content, &self.wpk, &self.wsk);
if (!self.old_kp.is_none()) {
let old_kp = self.old_kp.unwrap();
content = format!("{}revoked: wpk = {}\nrevoked: wsk = {}\n", content, &old_kp.wpk, &old_kp.wsk);
}
content = format!("{}t = {}\n", content, &self.t);
content = format!("{}wallet = {}\n", content, &self.wallet);
content = format!("{}w_com = {}\n", content, &self.w_com);
let close_token = self.close_tokens.get(&self.index);
let pay_token = self.pay_tokens.get(&self.index);
if (!close_token.is_none()) {
content = format!("{}close_token = {}\n", content, &self.close_tokens.get(&self.index).unwrap());
}
if (!pay_token.is_none()) {
content = format!("{}pay_token = {}\n", content, &self.pay_tokens.get(&self.index).unwrap());
}
write!(f, "CustomerState : (\n{}\n)", &content)
}
}
#[derive(Clone, Serialize, Deserialize)]
pub struct ChannelcloseM {
pub address: String,
pub revoke: Option<secp256k1::Signature>,
pub signature: secp256k1::Signature
}
///
/// Merchant wallet (NEW)
///
#[derive(Clone, Serialize, Deserialize)]
#[serde(bound(serialize = "<E as ff::ScalarEngine>::Fr: serde::Serialize, \
<E as pairing::Engine>::G1: serde::Serialize, \
<E as pairing::Engine>::G2: serde::Serialize"
))]
#[serde(bound(deserialize = "<E as ff::ScalarEngine>::Fr: serde::Deserialize<'de>, \
<E as pairing::Engine>::G1: serde::Deserialize<'de>, \
<E as pairing::Engine>::G2: serde::Deserialize<'de>"
))]
pub struct MerchantState<E: Engine> {
keypair: cl::BlindKeyPair<E>,
pub init_balance: i32,
pk: secp256k1::PublicKey, // pk_m
sk: secp256k1::SecretKey, // sk_m
comParams: CSMultiParams<E>,
pub keys: HashMap<String, PubKeyMap>,
pub pay_tokens: HashMap<String, cl::Signature<E>>
}
impl<E: Engine> MerchantState<E> {
pub fn new<R: Rng>(csprng: &mut R, channel: &mut ChannelState<E>, id: String) -> Self {
// generate keys here
let mut tx_kp = secp256k1::Secp256k1::new();
tx_kp.randomize(csprng);
let (wsk, wpk) = tx_kp.generate_keypair(csprng);
let cp = channel.cp.as_ref().unwrap(); // if not set, then panic!
MerchantState {
keypair: cp.pub_params.keypair.clone(),
init_balance: 0,
pk: wpk,
sk: wsk,
comParams: cp.pub_params.comParams.clone(),
keys: HashMap::new(), // store wpks/revoke_tokens
pay_tokens: HashMap::new()
}
}
pub fn init<R: Rng>(&mut self, csprng: &mut R, channel: &mut ChannelState<E>) -> ChannelToken<E> {
let cp = channel.cp.as_ref().unwrap(); // if not set, then panic!
let mpk = cp.pub_params.mpk.clone();
let cl_pk = cp.pub_params.keypair.get_public_key(&mpk);
return ChannelToken {
pk_c: None,
cl_pk_m: cl_pk.clone(), // extract the regular public key
pk_m: self.pk.clone(),
mpk: mpk,
comParams: self.comParams.clone()
}
}
pub fn init_balance(&mut self, balance: i32) {
// set by the escrow/funding transactionf for the channel
self.init_balance = balance;
}
pub fn issue_close_token<R: Rng>(&self, csprng: &mut R, cp: &ChannelParams<E>, com: &Commitment<E>, extend_close: bool) -> Signature<E> {
//println!("issue_close_token => generating token");
let x = hash_to_fr::<E>(String::from("close").into_bytes() );
let close_com = match extend_close {
true => self.comParams.extend_commit(com, &x),
false => com.clone()
};
//println!("com for close-token: {}", &close_com);
return self.keypair.sign_blind(csprng, &cp.pub_params.mpk, close_com);
}
pub fn issue_pay_token<R: Rng>(&self, csprng: &mut R, cp: &ChannelParams<E>, com: &Commitment<E>, remove_close: bool) -> Signature<E> {
//println!("issue_pay_token => generating token");
let x = hash_to_fr::<E>(String::from("close").into_bytes() );
let pay_com = match remove_close {
true => self.comParams.remove_commit(com, &x),
false => com.clone()
};
//println!("com for pay-token: {}", &pay_com);
return self.keypair.sign_blind(csprng, &cp.pub_params.mpk, pay_com);
}
pub fn verify_proof<R: Rng>(&self, csprng: &mut R, channel: &ChannelState<E>, com: &Commitment<E>, com_proof: &CommitmentProof<E>, cust_balance: i32, merch_balance: i32) -> ResultBoltSig<(Signature<E>, Signature<E>)> {
if (merch_balance != self.init_balance) {
return Err(BoltError::new("verify_proof - initial balance of merchant inconsistent with specified balance"));
}
let is_valid = nizk::verify_opening(&self.comParams, &com.c, &com_proof, cust_balance, merch_balance);
let cp = channel.cp.as_ref().unwrap();
if is_valid {
let close_token = self.issue_close_token(csprng, cp, com, true);
let pay_token = self.issue_pay_token(csprng, cp, com, false);
return Ok((close_token, pay_token));
}
Err(BoltError::new("verify_proof - Failed to verify PoK of commitment opening"))
}
fn store_wpk_with_token(&mut self, wpk: &secp256k1::PublicKey, pay_token: Signature<E>) {
// compute fingerprint on wpk
let wpk_str = util::compute_pub_key_fingerprint(&wpk);
self.pay_tokens.insert(wpk_str, pay_token);
}
fn get_pay_token(&self, wpk: &secp256k1::PublicKey) -> Signature<E> {
let wpk_str = util::compute_pub_key_fingerprint(&wpk);
return self.pay_tokens.get(&wpk_str).unwrap().clone();
}
pub fn verify_payment<R: Rng>(&mut self, csprng: &mut R, channel: &ChannelState<E>, proof: &NIZKProof<E>, com: &Commitment<E>, wpk: &secp256k1::PublicKey, amount: i32) -> ResultBoltSig<Signature<E>> {
let cp = channel.cp.as_ref().unwrap();
let pay_proof = proof.clone();
let prev_wpk = hash_pubkey_to_fr::<E>(&wpk);
let epsilon = util::convert_int_to_fr::<E>(amount);
if cp.pub_params.verify(pay_proof, epsilon, com, prev_wpk) {
// 1 - proceed with generating close and pay token
let close_token = self.issue_close_token(csprng, cp, com, false);
let pay_token = self.issue_pay_token(csprng, cp, com, true);
// let's store the pay token with the wpk for now
self.store_wpk_with_token(wpk, pay_token);
return Ok(close_token);
}
Err(BoltError::new("verify_payment - Failed to validate NIZK PoK for payment."))
}
pub fn verify_revoke_token(&self, revoke_token: &secp256k1::Signature, revoke_msg: &RevokedMessage, wpk: &secp256k1::PublicKey) -> ResultBoltSig<Signature<E>> {
let secp = secp256k1::Secp256k1::new();
let msg = secp256k1::Message::from_slice(&revoke_msg.hash_to_slice()).unwrap();
// verify that the revocation token is valid
if secp.verify(&msg, revoke_token, wpk).is_ok() {
return Ok(self.get_pay_token(wpk));
}
Err(BoltError::new("verify_revoke_token - Failed to verify the revoke token for wpk!"))
}
pub fn sign_revoke_message(&self, address: String, revoke_token: &Option<secp256k1::Signature>) -> ChannelcloseM {
let secp = secp256k1::Secp256k1::signing_only();
let mut msg = Vec::new();
msg.extend(address.as_bytes());
if !revoke_token.is_none() {
let r = revoke_token.unwrap().serialize_der().to_vec();
msg.extend(r);
}
let msg2 = secp256k1::Message::from_slice(&hash_to_slice(&msg) ).unwrap();
let merch_sig = secp.sign(&msg2, &self.sk);
return ChannelcloseM { address: address.clone(), revoke: revoke_token.clone(), signature: merch_sig };
}
}
#[cfg(test)]
mod tests {
use super::*;
use ff::Rand;
use pairing::bls12_381::{Bls12};
use rand::{SeedableRng};
use rand_xorshift::XorShiftRng;
#[test]
fn channel_util_works() {
let mut channel = ChannelState::<Bls12>::new(String::from("Channel A <-> B"), false);
let mut rng = &mut rand::thread_rng();
// run setup to generate the public parameters
channel.setup(&mut rng); // or load_setup params
let b0_cust = 100;
let b0_merch = 20;
// each party executes the init algorithm on the agreed initial challenge balance
// in order to derive the channel tokens
// initialize on the merchant side with balance: b0_merch
let mut merch_state = MerchantState::<Bls12>::new(rng, &mut channel, String::from("Merchant B"));
merch_state.init_balance(b0_merch);
// initialize the merchant wallet with the balance
let mut channel_token = merch_state.init(rng, &mut channel);
// retrieve commitment setup params (using merchant long lived pk params)
// initialize on the customer side with balance: b0_cust
let mut cust_state = CustomerState::<Bls12>::new(rng, &mut channel, &mut channel_token, b0_cust, b0_merch, String::from("Alice"));
// lets establish the channel
let cust_com_proof = cust_state.generate_proof(rng, &mut channel_token);
// first return the close token, then wait for escrow-tx confirmation
// then send the pay-token after confirmation
let (close_token, pay_token) = merch_state.verify_proof(rng, &channel, &cust_state.w_com, &cust_com_proof, b0_cust, b0_merch).unwrap();
// unblind tokens and verify signatures
assert!(cust_state.verify_close_token(&channel, &close_token));
assert!(cust_state.verify_pay_token(&channel, &pay_token));
println!("Done!");
// pay protocol tests
let amount = 10;
let (pay_proof, new_com, old_wpk, new_cw) = cust_state.generate_payment(rng, &channel, amount);
// new pay_token is not sent until revoke_token is obtained from the customer
let new_close_token = merch_state.verify_payment(rng, &channel, &pay_proof, &new_com, &old_wpk, amount).unwrap();
//println!("1 - Updated close Token : {}", new_close_token);
// unblind tokens and verify signatures
// assuming the pay_proof checks out, can go ahead and update internal state of cust_state
assert!(cust_state.update(new_cw));
//println!("2 - updated customer wallet!");
assert!(cust_state.verify_close_token(&channel, &new_close_token));
//println!("3 - verified the close token!");
// invalidate the previous state only if close token checks out
let (revoke_msg, revoke_sig) = cust_state.generate_revoke_token(&channel, &new_close_token).unwrap();
//println!("4 - Generated revoke token successfully.");
//println!("5 - Revoke token => {}", revoke_token);
let new_pay_token = merch_state.verify_revoke_token(&revoke_sig, &revoke_msg, &old_wpk).unwrap();
assert!(cust_state.verify_pay_token(&channel, &new_pay_token));
//println!("Validated revoke token!");
}
}
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