Fixing some stuff

This commit is contained in:
Lucas Soriano del Pino 2021-04-15 12:39:11 +10:00
parent a64a114bec
commit 52f30a6637
No known key found for this signature in database
GPG Key ID: EE611E973A1530E7

View File

@ -1,5 +1,6 @@
use anyhow::Result;
use curve25519_dalek;
#![allow(non_snake_case)]
use anyhow::{bail, Result};
use curve25519_dalek::constants::RISTRETTO_BASEPOINT_POINT;
use curve25519_dalek::digest::Digest;
use curve25519_dalek::ristretto::RistrettoPoint;
@ -33,7 +34,7 @@ fn final_challenge(
bytes.append(&mut L.compress().as_bytes().to_vec());
bytes.append(&mut R.compress().as_bytes().to_vec());
let mut hasher = Sha512::new().chain(bytes);
let hasher = Sha512::new().chain(bytes);
let h = Scalar::from_hash(hasher);
if i >= RING_SIZE - 2 {
@ -43,25 +44,16 @@ fn final_challenge(
}
}
struct AdaptorSig;
fn adaptor_sig(
pub struct AdaptorSig {
s_0_a: Scalar,
s_0_b: Scalar,
fake_responses: [Scalar; RING_SIZE - 1],
h_0: Scalar,
pk: RistrettoPoint,
/// Key image of the real key in the ring.
I: RistrettoPoint,
) -> AdaptorSig {
let s_prime_0 = s_0_a + s_0_b;
let l_0 = s_prime_0 * RISTRETTO_BASEPOINT_POINT + h_0 * pk;
let H_pk: RistrettoPoint = RistrettoPoint::hash_from_bytes::<Sha512>(pk.compress().as_bytes());
let r_0 = s_prime_0 * H_pk + h_0 * I;
AdaptorSig
}
struct Alice0 {
pub struct Alice0 {
// secret index is always 0
ring: [RistrettoPoint; RING_SIZE],
fake_responses: [Scalar; RING_SIZE - 1],
@ -77,7 +69,7 @@ struct Alice0 {
}
impl Alice0 {
fn new(
pub fn new(
ring: [RistrettoPoint; RING_SIZE],
msg: [u8; 32],
R_a: RistrettoPoint,
@ -85,9 +77,8 @@ impl Alice0 {
s_prime_a: Scalar,
) -> Self {
let mut fake_responses = [Scalar::zero(); RING_SIZE - 1];
for i in 0..(RING_SIZE - 1) {
fake_responses[i] = Scalar::random(&mut OsRng);
for response in fake_responses.iter_mut().take(RING_SIZE - 1) {
*response = Scalar::random(&mut OsRng);
}
Alice0 {
@ -100,7 +91,8 @@ impl Alice0 {
alpha_a: Scalar::random(&mut OsRng),
}
}
fn next_message(&self) -> Message0 {
pub fn next_message(&self) -> Message0 {
let p_k = self.ring.first().unwrap().compress();
// H_p(p_k)
let base_key_hashed_to_point: RistrettoPoint =
@ -109,7 +101,7 @@ impl Alice0 {
let I_a = self.s_prime_a * base_key_hashed_to_point;
let I_hat_a = self.alpha_a * base_key_hashed_to_point;
let T_a = self.s_prime_a * RISTRETTO_BASEPOINT_POINT;
let T_a = self.alpha_a * RISTRETTO_BASEPOINT_POINT;
Message0 {
pi_a: DleqProof::new(
@ -123,7 +115,7 @@ impl Alice0 {
}
}
fn receive(self, msg: Message1) -> Result<Alice1> {
pub fn receive(self, msg: Message1) -> Result<Alice1> {
let p_k = self.ring.first().unwrap().compress();
let base_key_hashed_to_point: RistrettoPoint =
RistrettoPoint::hash_from_bytes::<Sha512>(p_k.as_bytes());
@ -134,27 +126,33 @@ impl Alice0 {
msg.I_hat_b,
)?;
let I_a = self.s_prime_a * base_key_hashed_to_point;
let T_a = self.s_prime_a * RISTRETTO_BASEPOINT_POINT;
let T_a = self.alpha_a * RISTRETTO_BASEPOINT_POINT;
let I_hat_a = self.alpha_a * base_key_hashed_to_point;
let h_1 = {
Sha512::new()
let h_0 = {
let h_0 = Sha512::new()
.chain(self.msg)
.chain((T_a + msg.T_b + self.R_a).compress().as_bytes())
.chain((I_a + msg.I_b + self.R_prime_a).compress().as_bytes())
.chain(
(I_hat_a + msg.I_hat_b + self.R_prime_a)
.compress()
.as_bytes(),
);
Scalar::from_hash(h_0)
};
let h_0 = final_challenge(
let I_a = self.s_prime_a * base_key_hashed_to_point;
let h_last = final_challenge(
1,
self.fake_responses,
self.ring,
Scalar::from_hash(h_1),
h_0,
I_a,
msg.I_b,
self.msg,
);
let s_0_a = self.alpha_a - h_0 * self.s_prime_a;
let s_0_a = self.alpha_a - h_last * self.s_prime_a;
Ok(Alice1 {
ring: self.ring,
@ -164,12 +162,14 @@ impl Alice0 {
R_prime_a: self.R_prime_a,
s_prime_a: self.s_prime_a,
alpha_a: self.alpha_a,
h_0,
I_b: msg.I_b,
s_0_a,
})
}
}
struct Alice1 {
pub struct Alice1 {
// secret index is always 0
ring: [RistrettoPoint; RING_SIZE],
fake_responses: [Scalar; RING_SIZE - 1],
@ -182,25 +182,48 @@ struct Alice1 {
s_prime_a: Scalar,
// secret value:
alpha_a: Scalar,
h_0: Scalar,
I_b: RistrettoPoint,
s_0_a: Scalar,
}
impl Alice1 {
fn next_message(&self) -> Message2 {
pub fn next_message(&self) -> Message2 {
let base_key_hashed_to_point: RistrettoPoint = RistrettoPoint::hash_from_bytes::<Sha512>(
self.ring.first().unwrap().compress().as_bytes(),
);
let I_a = self.s_prime_a * base_key_hashed_to_point;
let T_a = self.s_prime_a * RISTRETTO_BASEPOINT_POINT;
let T_a = self.alpha_a * RISTRETTO_BASEPOINT_POINT;
let I_hat_a = self.alpha_a * base_key_hashed_to_point;
Message2 {
d_a: Opening::new(self.fake_responses, I_a, I_hat_a, T_a),
s_0_a: self.s_0_a,
}
}
pub fn receive(self, msg: Message3) -> Alice2 {
let base_key_hashed_to_point: RistrettoPoint = RistrettoPoint::hash_from_bytes::<Sha512>(
self.ring.first().unwrap().compress().as_bytes(),
);
let I_a = self.s_prime_a * base_key_hashed_to_point;
let adaptor_sig = AdaptorSig {
s_0_a: self.s_0_a,
s_0_b: msg.s_0_b,
fake_responses: self.fake_responses,
h_0: self.h_0,
I: I_a + self.I_b,
};
Alice2 { adaptor_sig }
}
}
struct Bob0 {
pub struct Alice2 {
pub adaptor_sig: AdaptorSig,
}
pub struct Bob0 {
// secret index is always 0
ring: [RistrettoPoint; RING_SIZE],
msg: [u8; 32],
@ -214,24 +237,24 @@ struct Bob0 {
}
impl Bob0 {
fn new(
pub fn new(
ring: [RistrettoPoint; RING_SIZE],
msg: [u8; 32],
R_b: RistrettoPoint,
R_prime_b: RistrettoPoint,
R_a: RistrettoPoint,
R_prime_a: RistrettoPoint,
s_b: Scalar,
) -> Self {
Bob0 {
ring,
msg,
R_a: R_b,
R_prime_a: R_prime_b,
R_a,
R_prime_a,
alpha_b: Scalar::random(&mut OsRng),
s_b,
}
}
fn receive(self, msg: Message0) -> Bob1 {
pub fn receive(self, msg: Message0) -> Bob1 {
Bob1 {
ring: self.ring,
msg: self.msg,
@ -245,7 +268,7 @@ impl Bob0 {
}
}
struct Bob1 {
pub struct Bob1 {
// secret index is always 0
ring: [RistrettoPoint; RING_SIZE],
msg: [u8; 32],
@ -261,7 +284,7 @@ struct Bob1 {
}
impl Bob1 {
fn next_message(&self) -> Message1 {
pub fn next_message(&self) -> Message1 {
let p_k = self.ring.first().unwrap().compress();
// H_p(p_k)
let base_key_hashed_to_point: RistrettoPoint =
@ -270,7 +293,7 @@ impl Bob1 {
let I_b = self.s_b * base_key_hashed_to_point;
let I_hat_b = self.alpha_b * base_key_hashed_to_point;
let T_b = self.s_b * RISTRETTO_BASEPOINT_POINT;
let T_b = self.alpha_b * RISTRETTO_BASEPOINT_POINT;
Message1 {
I_b,
@ -286,78 +309,59 @@ impl Bob1 {
}
}
fn receive(self, msg: Message2) -> Result<Bob2> {
pub fn receive(self, msg: Message2) -> Result<Bob2> {
let (fake_responses, I_a, I_hat_a, T_a) = msg.d_a.open(self.c_a)?;
let base_key_hashed_to_point: RistrettoPoint = RistrettoPoint::hash_from_bytes::<Sha512>(
self.ring.first().unwrap().compress().as_bytes(),
);
let I_b = self.s_b * base_key_hashed_to_point;
let T_b = self.s_b * RISTRETTO_BASEPOINT_POINT;
self.pi_a.verify(
RISTRETTO_BASEPOINT_POINT,
T_a,
base_key_hashed_to_point,
I_hat_a,
)?;
let h_1 = {
Sha512::new()
let T_b = self.alpha_b * RISTRETTO_BASEPOINT_POINT;
let I_hat_b = self.alpha_b * base_key_hashed_to_point;
let h_0 = {
let h_0 = Sha512::new()
.chain(self.msg)
.chain((T_a + T_b + self.R_a).compress().as_bytes())
.chain((I_a + I_b + self.R_prime_a).compress().as_bytes())
.chain((I_hat_a + I_hat_b + self.R_prime_a).compress().as_bytes());
Scalar::from_hash(h_0)
};
let h_0 = final_challenge(
1,
fake_responses,
self.ring,
Scalar::from_hash(h_1),
I_a,
I_b,
self.msg,
);
let I_b = self.s_b * base_key_hashed_to_point;
let h_last = final_challenge(1, fake_responses, self.ring, h_0, I_a, I_b, self.msg);
let s_0_b = self.alpha_b - h_0 * self.s_b;
let s_0_b = self.alpha_b - h_last * self.s_b;
Ok(Bob2 {
ring: self.ring,
msg: self.msg,
R_b: self.R_a,
R_prime_b: self.R_prime_a,
s_b: self.s_b,
alpha_b: self.alpha_b,
pi_a: self.pi_a,
fake_responses,
I_a: I_b,
I_hat_a,
T_a: T_b,
let adaptor_sig = AdaptorSig {
s_0_a: msg.s_0_a,
s_0_b,
})
fake_responses,
h_0,
I: I_a + I_b,
};
Ok(Bob2 { s_0_b, adaptor_sig })
}
}
struct Bob2 {
// secret index is always 0
ring: [RistrettoPoint; RING_SIZE],
msg: [u8; 32],
// encryption key
R_b: RistrettoPoint,
// R'a = r_a*H_p(p_k) where p_k is the signing public key
R_prime_b: RistrettoPoint,
s_b: Scalar,
alpha_b: Scalar,
// secret value:
pub struct Bob2 {
s_0_b: Scalar,
s_0_a: Scalar,
pi_a: DleqProof,
fake_responses: [Scalar; RING_SIZE - 1],
I_a: RistrettoPoint,
I_hat_a: RistrettoPoint,
T_a: RistrettoPoint,
pub adaptor_sig: AdaptorSig,
}
impl Bob2 {
fn next_message(&self) -> Message3 {
pub fn next_message(&self) -> Message3 {
Message3 { s_0_b: self.s_0_b }
}
}
struct DleqProof {
s: Scalar,
c: Scalar,
@ -371,7 +375,22 @@ impl DleqProof {
xH: RistrettoPoint,
x: Scalar,
) -> Self {
todo!()
let r = Scalar::random(&mut OsRng);
let rG = r * G;
let rH = r * H;
let hash = Sha512::new()
.chain(dbg!(G.compress()).as_bytes())
.chain(dbg!(xG.compress()).as_bytes())
.chain(dbg!(H.compress()).as_bytes())
.chain(dbg!(xH.compress()).as_bytes())
.chain(dbg!(rG.compress()).as_bytes())
.chain(dbg!(rH.compress()).as_bytes());
let c = Scalar::from_hash(hash);
let s = r + c * x;
Self { s, c }
}
fn verify(
&self,
@ -380,11 +399,40 @@ impl DleqProof {
H: RistrettoPoint,
xH: RistrettoPoint,
) -> Result<()> {
todo!()
let s = self.s;
let c = self.c;
let rG = {
let sG = s * G;
sG - c * xG
};
let rH = {
let sH = s * H;
sH - c * xH
};
let hash = Sha512::new()
.chain(dbg!(G.compress()).as_bytes())
.chain(dbg!(xG.compress()).as_bytes())
.chain(dbg!(H.compress()).as_bytes())
.chain(dbg!(xH.compress()).as_bytes())
.chain(dbg!(rG.compress()).as_bytes())
.chain(dbg!(rH.compress()).as_bytes());
let c_prime = Scalar::from_hash(hash);
if c != c_prime {
bail!("invalid DLEQ proof")
}
Ok(())
}
}
struct Commitment([u8; 32]);
#[derive(PartialEq)]
struct Commitment([u8; 64]);
impl Commitment {
fn new(
@ -393,7 +441,22 @@ impl Commitment {
I_hat_a: RistrettoPoint,
T_a: RistrettoPoint,
) -> Self {
todo!()
let fake_responses = fake_responses
.iter()
.flat_map(|r| r.as_bytes().to_vec())
.collect::<Vec<u8>>();
let hash = Sha512::new()
.chain(fake_responses)
.chain(I_a.compress().as_bytes())
.chain(I_hat_a.compress().as_bytes())
.chain(T_a.compress().as_bytes())
.finalize();
let mut commitment = [0u8; 64];
commitment.copy_from_slice(&hash);
Self(commitment)
}
}
@ -418,27 +481,35 @@ impl Opening {
T_a,
}
}
fn open(
self,
c_a: Commitment,
commitment: Commitment,
) -> Result<(
[Scalar; RING_SIZE - 1],
RistrettoPoint,
RistrettoPoint,
RistrettoPoint,
)> {
Ok((todo!()))
let self_commitment =
Commitment::new(self.fake_responses, self.I_a, self.I_hat_a, self.T_a);
if self_commitment == commitment {
Ok((self.fake_responses, self.I_a, self.I_hat_a, self.T_a))
} else {
bail!("opening does not match commitment")
}
}
}
// Alice Sends this to Bob
struct Message0 {
pub struct Message0 {
c_a: Commitment,
pi_a: DleqProof,
}
// Bob sends this to ALice
struct Message1 {
pub struct Message1 {
I_b: RistrettoPoint,
T_b: RistrettoPoint,
I_hat_b: RistrettoPoint,
@ -446,13 +517,13 @@ struct Message1 {
}
// Alice sends this to Bob
struct Message2 {
pub struct Message2 {
d_a: Opening,
s_0_a: Scalar,
}
// Bob sends this to Alice
struct Message3 {
pub struct Message3 {
s_0_b: Scalar,
}
@ -462,7 +533,44 @@ mod tests {
#[test]
fn sign_and_verify_success() {
let mut fake_responses = [Scalar::random(&mut OsRng); RING_SIZE - 1];
dbg!(fake_responses);
let msg = b"hello world, monero is amazing!!";
let s_prime_a = Scalar::random(&mut OsRng);
let s_b = Scalar::random(&mut OsRng);
let pk = (s_prime_a + s_b) * RISTRETTO_BASEPOINT_POINT;
let (r_a, R_a, R_prime_a) = {
let r_a = Scalar::random(&mut OsRng);
let R_a = r_a * RISTRETTO_BASEPOINT_POINT;
let pk_hashed_to_point: RistrettoPoint =
RistrettoPoint::hash_from_bytes::<Sha512>(pk.compress().as_bytes());
let R_prime_a = r_a * pk_hashed_to_point;
(r_a, R_a, R_prime_a)
};
let mut ring = [RistrettoPoint::default(); RING_SIZE];
ring[0] = pk;
for member in ring[1..].iter_mut().take(RING_SIZE - 1) {
*member = RistrettoPoint::random(&mut OsRng);
}
let alice = Alice0::new(ring, *msg, R_a, R_prime_a, s_prime_a);
let bob = Bob0::new(ring, *msg, R_a, R_prime_a, s_b);
let msg = alice.next_message();
let bob = bob.receive(msg);
let msg = bob.next_message();
let alice = alice.receive(msg).unwrap();
let msg = alice.next_message();
let bob = bob.receive(msg).unwrap();
let msg = bob.next_message();
let alice = alice.receive(msg);
}
}