remove shared secrete derivation from r0

This commit is contained in:
Sergio Chouhy 2025-08-25 14:51:46 -03:00
parent 20897596b0
commit d623812c24
12 changed files with 271 additions and 392 deletions

View File

@ -11,6 +11,7 @@ program-methods = { path = "program_methods" }
serde = "1.0.219"
sha2 = "0.10.9"
secp256k1 = "0.31.1"
k256 = "0.13.3"
rand = "0.8"
borsh = "1.5.7"
bytemuck = "1.13"

View File

@ -9,7 +9,6 @@ serde = { version = "1.0", default-features = false }
thiserror = { version = "2.0.12", optional = true }
bytemuck = { version = "1.13", optional = true }
chacha20 = { version = "0.9", default-features = false }
k256 = "0.13.3"
[features]
default = []

View File

@ -2,6 +2,7 @@ use chacha20::{
ChaCha20,
cipher::{KeyIvInit, StreamCipher},
};
use risc0_zkvm::{
serde::to_vec,
sha::{Impl, Sha256},
@ -25,14 +26,6 @@ use std::io::{Cursor, Read};
pub mod account;
pub mod program;
use k256::{
AffinePoint, EncodedPoint, FieldBytes, ProjectivePoint, PublicKey, Scalar,
elliptic_curve::{
PrimeField,
sec1::{FromEncodedPoint, ToEncodedPoint},
},
};
#[cfg(feature = "host")]
pub mod error;
@ -66,56 +59,23 @@ pub fn compute_root_associated_to_path(
result
}
pub type EphemeralPublicKey = Secp256k1Point;
pub type IncomingViewingPublicKey = Secp256k1Point;
pub type EphemeralSecretKey = [u8; 32];
impl From<&EphemeralSecretKey> for EphemeralPublicKey {
fn from(value: &EphemeralSecretKey) -> Self {
Secp256k1Point::from_scalar(*value)
}
}
#[derive(Serialize, Deserialize, Clone)]
#[cfg_attr(any(feature = "host", test), derive(Debug, PartialEq, Eq))]
pub struct Secp256k1Point(pub Vec<u8>);
impl Secp256k1Point {
pub fn from_scalar(value: [u8; 32]) -> Secp256k1Point {
let x_bytes: FieldBytes = value.into();
let x = Scalar::from_repr(x_bytes).unwrap();
let p = ProjectivePoint::GENERATOR * x;
let q = AffinePoint::from(p);
let enc = q.to_encoded_point(true);
Self(enc.as_bytes().to_vec())
}
}
pub type SharedSecretKey = [u8; 32];
#[derive(Serialize, Deserialize)]
#[cfg_attr(any(feature = "host", test), derive(Debug, Clone, PartialEq, Eq))]
pub struct EncryptedAccountData {
ciphertext: Vec<u8>,
epk: EphemeralPublicKey,
view_tag: u8,
}
pub struct Ciphertext(Vec<u8>);
impl EncryptedAccountData {
impl Ciphertext {
#[cfg(feature = "host")]
pub fn decrypt(self, isk: &[u8; 32], output_index: u32) -> Option<Account> {
let ss_bytes = Self::ecdh(isk, &self.epk.0.clone().try_into().unwrap());
let ipk = IncomingViewingPublicKey::from_scalar(*isk);
pub fn decrypt(self, shared_secret: &[u8; 32], output_index: u32) -> Option<Account> {
let key = Self::kdf(
ss_bytes,
&self.epk,
&ipk,
&shared_secret,
// &ipk,
// &commitment.to_byte_array(),
output_index,
);
let mut cipher = ChaCha20::new(&key.into(), &[0; 12].into());
let mut buffer = self.ciphertext;
let mut buffer = self.0;
cipher.apply_keystream(&mut buffer);
let mut cursor = Cursor::new(buffer.as_slice());
@ -124,71 +84,45 @@ impl EncryptedAccountData {
pub fn new(
account: &Account,
// commitment: &Commitment,
esk: &EphemeralSecretKey,
npk: &NullifierPublicKey,
ipk: &IncomingViewingPublicKey,
shared_secret: &[u8; 32],
// npk: &NullifierPublicKey,
// ipk: &IncomingViewingPublicKey,
output_index: u32,
) -> Self {
let mut buffer = account.to_bytes().to_vec();
let ss_bytes = Self::ecdh(esk, &ipk.0.clone().try_into().unwrap());
let epk = EphemeralPublicKey::from(esk);
let key = Self::kdf(
ss_bytes,
&epk,
ipk,
shared_secret,
// ipk,
// &commitment.to_byte_array(),
output_index,
);
let mut cipher = ChaCha20::new(&key.into(), &[0; 12].into());
cipher.apply_keystream(&mut buffer);
let view_tag = Self::view_tag(&npk, &ipk);
Self {
ciphertext: buffer,
epk,
view_tag,
}
// let view_tag = Self::view_tag(&npk, &ipk);
Self(buffer)
}
pub fn kdf(
ss_bytes: [u8; 32],
epk: &EphemeralPublicKey,
ipk: &IncomingViewingPublicKey,
ss_bytes: &[u8; 32],
// epk: &EphemeralPublicKey,
// ipk: &IncomingViewingPublicKey,
// commitment: &[u8; 32],
output_index: u32,
) -> [u8; 32] {
let mut bytes = Vec::new();
bytes.extend_from_slice(b"NSSA/v0.1/KDF-SHA256");
bytes.extend_from_slice(&ss_bytes);
bytes.extend_from_slice(&epk.0[..]);
bytes.extend_from_slice(&ipk.0[..]);
bytes.extend_from_slice(ss_bytes);
// bytes.extend_from_slice(&epk.0[..]);
// bytes.extend_from_slice(&ipk.0[..]);
// bytes.extend_from_slice(&commitment[..]);
bytes.extend_from_slice(&output_index.to_le_bytes());
Impl::hash_bytes(&bytes).as_bytes().try_into().unwrap()
}
pub fn ecdh(scalar: &[u8; 32], point: &[u8; 33]) -> [u8; 32] {
let scalar = Scalar::from_repr((*scalar).into()).unwrap();
let encoded = EncodedPoint::from_bytes(point).unwrap();
let pubkey_affine = AffinePoint::from_encoded_point(&encoded).unwrap();
let shared = ProjectivePoint::from(pubkey_affine) * scalar;
let shared_affine = shared.to_affine();
let encoded = shared_affine.to_encoded_point(false);
let x_bytes_slice = encoded.x().unwrap();
let mut x_bytes = [0u8; 32];
x_bytes.copy_from_slice(x_bytes_slice);
x_bytes
}
#[cfg(feature = "host")]
pub fn from_cursor(cursor: &mut Cursor<&[u8]>) -> Result<Self, NssaCoreError> {
let mut u32_bytes = [0; 4];
@ -198,33 +132,24 @@ impl EncryptedAccountData {
let mut ciphertext = vec![0; ciphertext_lenght as usize];
cursor.read_exact(&mut ciphertext)?;
let mut epk_bytes = vec![0; 33];
cursor.read_exact(&mut epk_bytes)?;
// let mut epk_bytes = vec![0; 33];
// cursor.read_exact(&mut epk_bytes)?;
//
// let mut tag_bytes = [0; 1];
// cursor.read_exact(&mut tag_bytes)?;
let mut tag_bytes = [0; 1];
cursor.read_exact(&mut tag_bytes)?;
Ok(Self {
ciphertext,
epk: Secp256k1Point(epk_bytes),
view_tag: tag_bytes[0],
})
}
fn view_tag(npk: &NullifierPublicKey, ipk: &&IncomingViewingPublicKey) -> u8 {
// TODO: implement
0
Ok(Self(ciphertext))
}
}
impl EncryptedAccountData {
impl Ciphertext {
pub fn to_bytes(&self) -> Vec<u8> {
let mut bytes = Vec::new();
let ciphertext_length: u32 = self.ciphertext.len() as u32;
let ciphertext_length: u32 = self.0.len() as u32;
bytes.extend_from_slice(&ciphertext_length.to_le_bytes());
bytes.extend_from_slice(&self.ciphertext);
bytes.extend_from_slice(&self.epk.0);
bytes.push(self.view_tag);
bytes.extend_from_slice(&self.0);
// bytes.extend_from_slice(&self.epk.0);
// bytes.push(self.view_tag);
bytes
}
@ -237,8 +162,9 @@ pub struct PrivacyPreservingCircuitInput {
pub private_account_nonces: Vec<Nonce>,
pub private_account_keys: Vec<(
NullifierPublicKey,
IncomingViewingPublicKey,
EphemeralSecretKey,
SharedSecretKey,
// IncomingViewingPublicKey,
// EphemeralSecretKey,
)>,
pub private_account_auth: Vec<(NullifierSecretKey, MembershipProof)>,
pub program_id: ProgramId,
@ -249,7 +175,7 @@ pub struct PrivacyPreservingCircuitInput {
pub struct PrivacyPreservingCircuitOutput {
pub public_pre_states: Vec<AccountWithMetadata>,
pub public_post_states: Vec<Account>,
pub encrypted_private_post_states: Vec<EncryptedAccountData>,
pub ciphertexts: Vec<Ciphertext>,
pub new_commitments: Vec<Commitment>,
pub new_nullifiers: Vec<(Nullifier, CommitmentSetDigest)>,
}
@ -268,7 +194,7 @@ mod tests {
use risc0_zkvm::serde::from_slice;
use crate::{
EncryptedAccountData, EphemeralPublicKey, PrivacyPreservingCircuitOutput, Secp256k1Point,
Ciphertext, PrivacyPreservingCircuitOutput,
account::{Account, AccountWithMetadata, Commitment, Nullifier, NullifierPublicKey},
};
@ -301,11 +227,10 @@ mod tests {
data: b"post state data".to_vec(),
nonce: 18446744073709551615,
}],
encrypted_private_post_states: vec![EncryptedAccountData {
ciphertext: vec![255, 255, 1, 1, 2, 2],
epk: EphemeralPublicKey::from_scalar([123; 32]),
view_tag: 1,
}],
ciphertexts: vec![
Ciphertext(vec![255, 255, 1, 1, 2, 2]), // epk: EphemeralPublicKey::from_scalar([123; 32]),
// view_tag: 1,
],
new_commitments: vec![Commitment::new(
&NullifierPublicKey::from(&[1; 32]),
&Account::default(),
@ -324,15 +249,12 @@ mod tests {
}
#[test]
fn test_encrypted_account_data_to_bytes_roundtrip() {
let data = EncryptedAccountData {
ciphertext: vec![255, 255, 1, 1, 2, 2],
epk: EphemeralPublicKey::from_scalar([123; 32]),
view_tag: 95,
};
fn test_ciphertext_to_bytes_roundtrip() {
let data = Ciphertext(vec![255, 255, 1, 1, 2, 2]);
let bytes = data.to_bytes();
let mut cursor = Cursor::new(bytes.as_slice());
let data_from_cursor = EncryptedAccountData::from_cursor(&mut cursor).unwrap();
let data_from_cursor = Ciphertext::from_cursor(&mut cursor).unwrap();
assert_eq!(data, data_from_cursor);
}
}

View File

@ -297,24 +297,12 @@ dependencies = [
"windows-targets 0.52.6",
]
[[package]]
name = "base16ct"
version = "0.2.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "4c7f02d4ea65f2c1853089ffd8d2787bdbc63de2f0d29dedbcf8ccdfa0ccd4cf"
[[package]]
name = "base64"
version = "0.22.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "72b3254f16251a8381aa12e40e3c4d2f0199f8c6508fbecb9d91f575e0fbb8c6"
[[package]]
name = "base64ct"
version = "1.8.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "55248b47b0caf0546f7988906588779981c43bb1bc9d0c44087278f80cdb44ba"
[[package]]
name = "bincode"
version = "1.3.3"
@ -568,18 +556,6 @@ dependencies = [
"libc",
]
[[package]]
name = "crypto-bigint"
version = "0.5.5"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "0dc92fb57ca44df6db8059111ab3af99a63d5d0f8375d9972e319a379c6bab76"
dependencies = [
"generic-array",
"rand_core 0.6.4",
"subtle",
"zeroize",
]
[[package]]
name = "crypto-common"
version = "0.1.6"
@ -625,16 +601,6 @@ dependencies = [
"syn 2.0.104",
]
[[package]]
name = "der"
version = "0.7.10"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "e7c1832837b905bbfb5101e07cc24c8deddf52f93225eee6ead5f4d63d53ddcb"
dependencies = [
"const-oid",
"zeroize",
]
[[package]]
name = "derivative"
version = "2.2.0"
@ -764,20 +730,6 @@ dependencies = [
"proc-macro-error",
]
[[package]]
name = "ecdsa"
version = "0.16.9"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "ee27f32b5c5292967d2d4a9d7f1e0b0aed2c15daded5a60300e4abb9d8020bca"
dependencies = [
"der",
"digest",
"elliptic-curve",
"rfc6979",
"signature",
"spki",
]
[[package]]
name = "educe"
version = "0.6.0"
@ -802,25 +754,6 @@ version = "0.7.4"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "4445909572dbd556c457c849c4ca58623d84b27c8fff1e74b0b4227d8b90d17b"
[[package]]
name = "elliptic-curve"
version = "0.13.8"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "b5e6043086bf7973472e0c7dff2142ea0b680d30e18d9cc40f267efbf222bd47"
dependencies = [
"base16ct",
"crypto-bigint",
"digest",
"ff",
"generic-array",
"group",
"pkcs8",
"rand_core 0.6.4",
"sec1",
"subtle",
"zeroize",
]
[[package]]
name = "embedded-io"
version = "0.4.0"
@ -884,16 +817,6 @@ version = "2.3.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "37909eebbb50d72f9059c3b6d82c0463f2ff062c9e95845c43a6c9c0355411be"
[[package]]
name = "ff"
version = "0.13.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "c0b50bfb653653f9ca9095b427bed08ab8d75a137839d9ad64eb11810d5b6393"
dependencies = [
"rand_core 0.6.4",
"subtle",
]
[[package]]
name = "fnv"
version = "1.0.7"
@ -1006,7 +929,6 @@ checksum = "85649ca51fd72272d7821adaf274ad91c288277713d9c18820d8499a7ff69e9a"
dependencies = [
"typenum",
"version_check",
"zeroize",
]
[[package]]
@ -1042,17 +964,6 @@ version = "0.31.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "07e28edb80900c19c28f1072f2e8aeca7fa06b23cd4169cefe1af5aa3260783f"
[[package]]
name = "group"
version = "0.13.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "f0f9ef7462f7c099f518d754361858f86d8a07af53ba9af0fe635bbccb151a63"
dependencies = [
"ff",
"rand_core 0.6.4",
"subtle",
]
[[package]]
name = "hashbrown"
version = "0.14.5"
@ -1104,15 +1015,6 @@ version = "0.4.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "6fe2267d4ed49bc07b63801559be28c718ea06c4738b7a03c94df7386d2cde46"
[[package]]
name = "hmac"
version = "0.12.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "6c49c37c09c17a53d937dfbb742eb3a961d65a994e6bcdcf37e7399d0cc8ab5e"
dependencies = [
"digest",
]
[[package]]
name = "http"
version = "1.3.1"
@ -1403,20 +1305,6 @@ dependencies = [
"wasm-bindgen",
]
[[package]]
name = "k256"
version = "0.13.4"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "f6e3919bbaa2945715f0bb6d3934a173d1e9a59ac23767fbaaef277265a7411b"
dependencies = [
"cfg-if",
"ecdsa",
"elliptic-curve",
"once_cell",
"sha2",
"signature",
]
[[package]]
name = "keccak"
version = "0.1.5"
@ -1588,7 +1476,6 @@ name = "nssa-core"
version = "0.1.0"
dependencies = [
"chacha20",
"k256",
"risc0-zkvm",
"serde",
]
@ -1675,16 +1562,6 @@ version = "0.1.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "8b870d8c151b6f2fb93e84a13146138f05d02ed11c7e7c54f8826aaaf7c9f184"
[[package]]
name = "pkcs8"
version = "0.10.2"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "f950b2377845cebe5cf8b5165cb3cc1a5e0fa5cfa3e1f7f55707d8fd82e0a7b7"
dependencies = [
"der",
"spki",
]
[[package]]
name = "postcard"
version = "1.1.3"
@ -1903,9 +1780,6 @@ name = "rand_core"
version = "0.6.4"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "ec0be4795e2f6a28069bec0b5ff3e2ac9bafc99e6a9a7dc3547996c5c816922c"
dependencies = [
"getrandom 0.2.16",
]
[[package]]
name = "rand_core"
@ -1998,16 +1872,6 @@ dependencies = [
"webpki-roots",
]
[[package]]
name = "rfc6979"
version = "0.4.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "f8dd2a808d456c4a54e300a23e9f5a67e122c3024119acbfd73e3bf664491cb2"
dependencies = [
"hmac",
"subtle",
]
[[package]]
name = "ring"
version = "0.17.14"
@ -2329,20 +2193,6 @@ dependencies = [
"yaml-rust2",
]
[[package]]
name = "sec1"
version = "0.7.3"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "d3e97a565f76233a6003f9f5c54be1d9c5bdfa3eccfb189469f11ec4901c47dc"
dependencies = [
"base16ct",
"der",
"generic-array",
"pkcs8",
"subtle",
"zeroize",
]
[[package]]
name = "semver"
version = "1.0.26"
@ -2422,16 +2272,6 @@ version = "1.3.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "0fda2ff0d084019ba4d7c6f371c95d8fd75ce3524c3cb8fb653a3023f6323e64"
[[package]]
name = "signature"
version = "2.2.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "77549399552de45a898a580c1b41d445bf730df867cc44e6c0233bbc4b8329de"
dependencies = [
"digest",
"rand_core 0.6.4",
]
[[package]]
name = "slab"
version = "0.4.10"
@ -2470,16 +2310,6 @@ version = "0.9.8"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "6980e8d7511241f8acf4aebddbb1ff938df5eebe98691418c4468d0b72a96a67"
[[package]]
name = "spki"
version = "0.7.3"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "d91ed6c858b01f942cd56b37a94b3e0a1798290327d1236e4d9cf4eaca44d29d"
dependencies = [
"base64ct",
"der",
]
[[package]]
name = "stability"
version = "0.2.1"
@ -3394,8 +3224,3 @@ dependencies = [
"quote",
"syn 2.0.104",
]
[[patch.unused]]
name = "k256"
version = "0.13.3"
source = "git+https://github.com/risc0/RustCrypto-elliptic-curves?tag=k256%2Fv0.13.3-risczero.1#ff5d67b095cfcc2569b7789f2079ed87ef2c7756"

View File

@ -8,7 +8,3 @@ edition = "2021"
[dependencies]
risc0-zkvm = { version = "2.3.1", default-features = false, features = ['std'] }
nssa-core = { path = "../../core" }
[patch.crates-io]
k256 = { git = "https://github.com/risc0/RustCrypto-elliptic-curves", tag = "k256/v0.13.3-risczero.1" }

View File

@ -4,8 +4,7 @@ use nssa_core::{
account::{Account, AccountWithMetadata, Commitment, Nullifier, NullifierPublicKey},
compute_root_associated_to_path,
program::{validate_execution, ProgramOutput, DEFAULT_PROGRAM_ID},
CommitmentSetDigest, EncryptedAccountData, EphemeralPublicKey, EphemeralSecretKey,
IncomingViewingPublicKey, PrivacyPreservingCircuitInput, PrivacyPreservingCircuitOutput,
Ciphertext, CommitmentSetDigest, PrivacyPreservingCircuitInput, PrivacyPreservingCircuitOutput,
};
fn main() {
@ -42,7 +41,7 @@ fn main() {
// and will be populated next.
let mut public_pre_states: Vec<AccountWithMetadata> = Vec::new();
let mut public_post_states: Vec<Account> = Vec::new();
let mut encrypted_private_post_states: Vec<EncryptedAccountData> = Vec::new();
let mut ciphertexts: Vec<Ciphertext> = Vec::new();
let mut new_commitments: Vec<Commitment> = Vec::new();
let mut new_nullifiers: Vec<(Nullifier, CommitmentSetDigest)> = Vec::new();
@ -67,7 +66,8 @@ fn main() {
}
1 | 2 => {
let new_nonce = private_nonces_iter.next().expect("Missing private nonce");
let (Npk, Ipk, esk) = private_keys_iter.next().expect("Missing private keys");
// let (Npk, Ipk, esk) = private_keys_iter.next().expect("Missing keys");
let (Npk, shared_secret) = private_keys_iter.next().expect("Missing keys");
if visibility_mask[i] == 1 {
// Private account with authentication
@ -116,17 +116,18 @@ fn main() {
let commitment_post = Commitment::new(Npk, &post_with_updated_values);
// Encrypt and push post state
let encrypted_account = EncryptedAccountData::new(
let encrypted_account = Ciphertext::new(
&post_with_updated_values,
shared_secret,
// &commitment_post,
esk,
Npk,
Ipk,
// esk,
// Npk,
// Ipk,
output_index,
);
new_commitments.push(commitment_post);
encrypted_private_post_states.push(encrypted_account);
ciphertexts.push(encrypted_account);
output_index += 1;
}
_ => panic!("Invalid visibility mask value"),
@ -148,7 +149,7 @@ fn main() {
let output = PrivacyPreservingCircuitOutput {
public_pre_states,
public_post_states,
encrypted_private_post_states,
ciphertexts,
new_commitments,
new_nullifiers,
};

View File

@ -1,6 +1,6 @@
use nssa_core::{
CommitmentSetDigest, EphemeralSecretKey, IncomingViewingPublicKey, MembershipProof,
PrivacyPreservingCircuitInput, PrivacyPreservingCircuitOutput,
CommitmentSetDigest, MembershipProof, PrivacyPreservingCircuitInput,
PrivacyPreservingCircuitOutput, SharedSecretKey,
account::{Account, AccountWithMetadata, Nonce, NullifierPublicKey, NullifierSecretKey},
program::{InstructionData, ProgramId, ProgramOutput},
};
@ -28,8 +28,9 @@ pub fn execute_and_prove(
private_account_nonces: &[u128],
private_account_keys: &[(
NullifierPublicKey,
IncomingViewingPublicKey,
EphemeralSecretKey,
SharedSecretKey,
// IncomingViewingPublicKey,
// EphemeralSecretKey,
)],
private_account_auth: &[(NullifierSecretKey, MembershipProof)],
program: &Program,
@ -90,7 +91,7 @@ fn execute_and_prove_program(
#[cfg(test)]
mod tests {
use nssa_core::{
EncryptedAccountData,
Ciphertext,
account::{
Account, AccountWithMetadata, Commitment, Nullifier, NullifierPublicKey,
NullifierSecretKey,
@ -101,7 +102,10 @@ mod tests {
use crate::{
Address, V01State,
merkle_tree::MerkleTree,
privacy_preserving_transaction::circuit::{Proof, execute_and_prove},
privacy_preserving_transaction::{
circuit::{Proof, execute_and_prove},
message::{EncryptedAccountData, EphemeralPublicKey},
},
program::Program,
state::{
CommitmentSet,
@ -147,12 +151,18 @@ mod tests {
let expected_sender_pre = sender.clone();
let recipient_keys = test_private_account_keys_1();
let esk = [3; 32];
let shared_secret =
EncryptedAccountData::compute_shared_secret(&esk, &recipient_keys.ivk());
let epk = EphemeralPublicKey::from_scalar(esk);
let (output, proof) = execute_and_prove(
&[sender, recipient],
&Program::serialize_instruction(balance_to_move).unwrap(),
&[0, 2],
&[0xdeadbeef],
&[(recipient_keys.npk(), recipient_keys.ivk(), [3; 32])],
&[(recipient_keys.npk(), shared_secret)],
&[],
&Program::authenticated_transfer_program(),
)
@ -166,11 +176,11 @@ mod tests {
assert_eq!(sender_post, expected_sender_post);
assert_eq!(output.new_commitments.len(), 1);
assert_eq!(output.new_nullifiers.len(), 0);
assert_eq!(output.encrypted_private_post_states.len(), 1);
assert_eq!(output.ciphertexts.len(), 1);
let recipient_post = output.encrypted_private_post_states[0]
let recipient_post = output.ciphertexts[0]
.clone()
.decrypt(&recipient_keys.isk, 0)
.decrypt(&shared_secret, 0)
.unwrap();
assert_eq!(recipient_post, expected_recipient_post);
}
@ -222,14 +232,24 @@ mod tests {
Commitment::new(&recipient_keys.npk(), &expected_private_account_2),
];
let esk_1 = [3; 32];
let shared_secret_1 =
EncryptedAccountData::compute_shared_secret(&esk_1, &sender_keys.ivk());
let epk_1 = EphemeralPublicKey::from_scalar(esk_1);
let esk_2 = [5; 32];
let shared_secret_2 =
EncryptedAccountData::compute_shared_secret(&esk_2, &recipient_keys.ivk());
let epk_2 = EphemeralPublicKey::from_scalar(esk_2);
let (output, proof) = execute_and_prove(
&[sender_pre.clone(), recipient],
&Program::serialize_instruction(balance_to_move).unwrap(),
&[1, 2],
&[0xdeadbeef1, 0xdeadbeef2],
&[
(sender_keys.npk(), sender_keys.ivk(), [3; 32]),
(recipient_keys.npk(), recipient_keys.ivk(), [5; 32]),
(sender_keys.npk(), shared_secret_1),
(recipient_keys.npk(), shared_secret_2),
],
&[(
sender_keys.nsk,
@ -244,17 +264,17 @@ mod tests {
assert!(output.public_post_states.is_empty());
assert_eq!(output.new_commitments, expected_new_commitments);
assert_eq!(output.new_nullifiers, expected_new_nullifiers);
assert_eq!(output.encrypted_private_post_states.len(), 2);
assert_eq!(output.ciphertexts.len(), 2);
let recipient_post_1 = output.encrypted_private_post_states[0]
let recipient_post_1 = output.ciphertexts[0]
.clone()
.decrypt(&sender_keys.isk, 0)
.decrypt(&shared_secret_1, 0)
.unwrap();
assert_eq!(recipient_post_1, expected_private_account_1);
let recipient_post_2 = output.encrypted_private_post_states[1]
let recipient_post_2 = output.ciphertexts[1]
.clone()
.decrypt(&recipient_keys.isk, 1)
.decrypt(&shared_secret_2, 1)
.unwrap();
assert_eq!(recipient_post_2, expected_private_account_2);
}

View File

@ -3,17 +3,50 @@
use std::io::{Cursor, Read};
use nssa_core::{
EncryptedAccountData,
Ciphertext,
account::{Account, Commitment, Nullifier},
};
use crate::{Address, error::NssaError};
use crate::{
Address,
error::NssaError,
privacy_preserving_transaction::message::{
EncryptedAccountData, EphemeralPublicKey, Secp256k1Point,
},
};
use super::message::Message;
const MESSAGE_ENCODING_PREFIX_LEN: usize = 22;
const MESSAGE_ENCODING_PREFIX: &[u8; MESSAGE_ENCODING_PREFIX_LEN] = b"\x01/NSSA/v0.1/TxMessage/";
impl EncryptedAccountData {
pub(crate) fn to_bytes(&self) -> Vec<u8> {
let mut bytes = self.ciphertext.to_bytes();
bytes.extend_from_slice(&self.epk.0);
bytes.push(self.view_tag);
bytes
}
pub fn from_cursor(cursor: &mut Cursor<&[u8]>) -> Result<Self, NssaError> {
let ciphertext = Ciphertext::from_cursor(cursor)?;
let mut epk_bytes = vec![0; 33];
cursor.read_exact(&mut epk_bytes)?;
let epk = Secp256k1Point(epk_bytes);
let mut tag_bytes = [0; 1];
cursor.read_exact(&mut tag_bytes)?;
let view_tag = tag_bytes[0];
Ok(Self {
ciphertext,
epk,
view_tag,
})
}
}
impl Message {
pub(crate) fn to_bytes(&self) -> Vec<u8> {
let mut bytes = MESSAGE_ENCODING_PREFIX.to_vec();

View File

@ -1,9 +1,80 @@
use std::io::Cursor;
use k256::{
AffinePoint, EncodedPoint, FieldBytes, ProjectivePoint, PublicKey, Scalar,
elliptic_curve::{
PrimeField,
sec1::{FromEncodedPoint, ToEncodedPoint},
},
};
use nssa_core::{
CommitmentSetDigest, EncryptedAccountData,
Ciphertext, CommitmentSetDigest, PrivacyPreservingCircuitOutput, SharedSecretKey,
account::{Account, Commitment, Nonce, Nullifier},
};
use serde::{Deserialize, Serialize};
use crate::Address;
use crate::{Address, error::NssaError};
#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
pub struct Secp256k1Point(pub(crate) Vec<u8>);
impl Secp256k1Point {
pub fn from_scalar(value: [u8; 32]) -> Secp256k1Point {
let x_bytes: FieldBytes = value.into();
let x = Scalar::from_repr(x_bytes).unwrap();
let p = ProjectivePoint::GENERATOR * x;
let q = AffinePoint::from(p);
let enc = q.to_encoded_point(true);
Self(enc.as_bytes().to_vec())
}
}
pub type EphemeralSecretKey = [u8; 32];
pub type EphemeralPublicKey = Secp256k1Point;
pub type IncomingViewingPublicKey = Secp256k1Point;
impl From<&EphemeralSecretKey> for EphemeralPublicKey {
fn from(value: &EphemeralSecretKey) -> Self {
Secp256k1Point::from_scalar(*value)
}
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct EncryptedAccountData {
pub(crate) ciphertext: Ciphertext,
pub(crate) epk: EphemeralPublicKey,
pub(crate) view_tag: u8,
}
impl EncryptedAccountData {
pub fn decrypt(
self,
isk: &[u8; 32],
epk: &EphemeralPublicKey,
output_index: u32,
) -> Option<Account> {
let shared_secret = Self::compute_shared_secret(isk, &epk);
self.ciphertext.decrypt(&shared_secret, output_index)
}
pub fn compute_shared_secret(scalar: &[u8; 32], point: &Secp256k1Point) -> SharedSecretKey {
let scalar = Scalar::from_repr((*scalar).into()).unwrap();
let point: [u8; 33] = point.0.clone().try_into().unwrap();
let encoded = EncodedPoint::from_bytes(point).unwrap();
let pubkey_affine = AffinePoint::from_encoded_point(&encoded).unwrap();
let shared = ProjectivePoint::from(pubkey_affine) * scalar;
let shared_affine = shared.to_affine();
let encoded = shared_affine.to_encoded_point(false);
let x_bytes_slice = encoded.x().unwrap();
let mut x_bytes = [0u8; 32];
x_bytes.copy_from_slice(x_bytes_slice);
x_bytes
}
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct Message {
@ -16,22 +87,36 @@ pub struct Message {
}
impl Message {
pub fn new(
pub fn try_from_circuit_output(
public_addresses: Vec<Address>,
nonces: Vec<Nonce>,
public_post_states: Vec<Account>,
encrypted_private_post_states: Vec<EncryptedAccountData>,
new_commitments: Vec<Commitment>,
new_nullifiers: Vec<(Nullifier, CommitmentSetDigest)>,
) -> Self {
Self {
ephemeral_public_keys: Vec<EphemeralPublicKey>,
output: PrivacyPreservingCircuitOutput,
) -> Result<Self, NssaError> {
if ephemeral_public_keys.len() != output.ciphertexts.len() {
return Err(NssaError::InvalidInput(
"Ephemeral public keys and ciphertexts length mismatch".into(),
));
}
let encrypted_private_post_states = output
.ciphertexts
.into_iter()
.zip(ephemeral_public_keys)
.map(|(ciphertext, epk)| EncryptedAccountData {
ciphertext,
epk,
view_tag: 0, // TODO: implement
})
.collect();
Ok(Self {
public_addresses,
nonces,
public_post_states,
public_post_states: output.public_post_states,
encrypted_private_post_states,
new_commitments,
new_nullifiers,
}
new_commitments: output.new_commitments,
new_nullifiers: output.new_nullifiers,
})
}
}
@ -78,23 +163,6 @@ pub mod tests {
}
}
#[test]
fn test_constructor() {
let message = message_for_tests();
let expected_message = message.clone();
let message = Message::new(
message.public_addresses,
message.nonces,
message.public_post_states,
message.encrypted_private_post_states,
message.new_commitments,
message.new_nullifiers,
);
assert_eq!(message, expected_message);
}
#[test]
fn test_message_serialization_roundtrip() {
let message = message_for_tests();

View File

@ -5,6 +5,6 @@ mod witness_set;
pub mod circuit;
pub use message::Message;
pub use message::{Message, IncomingViewingPublicKey, EphemeralPublicKey, EphemeralSecretKey, EncryptedAccountData};
pub use transaction::PrivacyPreservingTransaction;
pub use witness_set::WitnessSet;

View File

@ -1,10 +1,11 @@
use std::collections::{HashMap, HashSet};
use nssa_core::account::{Account, AccountWithMetadata, Commitment, Nullifier};
use nssa_core::{CommitmentSetDigest, EncryptedAccountData, PrivacyPreservingCircuitOutput};
use nssa_core::{Ciphertext, CommitmentSetDigest, PrivacyPreservingCircuitOutput};
use crate::error::NssaError;
use crate::privacy_preserving_transaction::circuit::Proof;
use crate::privacy_preserving_transaction::message::EncryptedAccountData;
use crate::{Address, V01State};
use super::message::Message;
@ -145,7 +146,11 @@ fn check_privacy_preserving_circuit_proof_is_valid(
let output = PrivacyPreservingCircuitOutput {
public_pre_states: public_pre_states.to_vec(),
public_post_states: public_post_states.to_vec(),
encrypted_private_post_states: encrypted_private_post_states.to_vec(),
ciphertexts: encrypted_private_post_states
.iter()
.cloned()
.map(|value| value.ciphertext)
.collect(),
new_commitments: new_commitments.to_vec(),
new_nullifiers: new_nullifiers.to_vec(),
};

View File

@ -222,14 +222,15 @@ pub mod tests {
Address, PublicKey, PublicTransaction, V01State,
error::NssaError,
privacy_preserving_transaction::{
Message, PrivacyPreservingTransaction, WitnessSet, circuit,
EncryptedAccountData, EphemeralPublicKey, IncomingViewingPublicKey, Message,
PrivacyPreservingTransaction, WitnessSet, circuit,
},
program::Program,
public_transaction,
signature::PrivateKey,
};
use nssa_core::{
IncomingViewingPublicKey,
Ciphertext,
account::{
Account, AccountWithMetadata, Commitment, Nonce, Nullifier, NullifierPublicKey,
NullifierSecretKey,
@ -780,11 +781,11 @@ pub mod tests {
balance_to_move: u128,
state: &V01State,
) -> PrivacyPreservingTransaction {
let esk = [3; 32];
let sender = AccountWithMetadata {
account: state.get_account_by_address(&sender_keys.address()),
is_authorized: true,
};
let sender_nonce = sender.account.nonce;
let recipient = AccountWithMetadata {
@ -792,25 +793,28 @@ pub mod tests {
is_authorized: false,
};
let esk = [3; 32];
let shared_secret =
EncryptedAccountData::compute_shared_secret(&esk, &recipient_keys.ivk());
let epk = EphemeralPublicKey::from_scalar(esk);
let (output, proof) = circuit::execute_and_prove(
&[sender, recipient],
&Program::serialize_instruction(balance_to_move).unwrap(),
&[0, 2],
&[0xdeadbeef],
&[(recipient_keys.npk(), recipient_keys.ivk(), esk)],
&[(recipient_keys.npk(), shared_secret)],
&[],
&Program::authenticated_transfer_program(),
)
.unwrap();
let message = Message::new(
let message = Message::try_from_circuit_output(
vec![sender_keys.address()],
vec![sender_nonce],
output.public_post_states,
output.encrypted_private_post_states,
output.new_commitments.clone(),
output.new_nullifiers,
);
vec![epk],
output,
).unwrap();
let witness_set = WitnessSet::for_message(&message, proof, &[&sender_keys.signing_key]);
PrivacyPreservingTransaction::new(message, witness_set)
@ -835,14 +839,24 @@ pub mod tests {
is_authorized: false,
};
let esk_1 = [3; 32];
let shared_secret_1 =
EncryptedAccountData::compute_shared_secret(&esk_1, &sender_keys.ivk());
let epk_1 = EphemeralPublicKey::from_scalar(esk_1);
let esk_2 = [3; 32];
let shared_secret_2 =
EncryptedAccountData::compute_shared_secret(&esk_2, &recipient_keys.ivk());
let epk_2 = EphemeralPublicKey::from_scalar(esk_2);
let (output, proof) = circuit::execute_and_prove(
&[sender_pre, recipient_pre],
&Program::serialize_instruction(balance_to_move).unwrap(),
&[1, 2],
&new_nonces,
&[
(sender_keys.npk(), sender_keys.ivk(), [3; 32]),
(recipient_keys.npk(), recipient_keys.ivk(), [4; 32]),
(sender_keys.npk(), shared_secret_1),
(recipient_keys.npk(), shared_secret_2),
],
&[(
sender_keys.nsk,
@ -856,14 +870,7 @@ pub mod tests {
)
.unwrap();
let message = Message::new(
vec![],
vec![],
output.public_post_states,
output.encrypted_private_post_states,
output.new_commitments.clone(),
output.new_nullifiers,
);
let message = Message::try_from_circuit_output(vec![], vec![], vec![epk_1, epk_2], output).unwrap();
let witness_set = WitnessSet::for_message(&message, proof, &[]);
@ -889,12 +896,16 @@ pub mod tests {
is_authorized: false,
};
let esk = [3; 32];
let shared_secret = EncryptedAccountData::compute_shared_secret(&esk, &sender_keys.ivk());
let epk = EphemeralPublicKey::from_scalar(esk);
let (output, proof) = circuit::execute_and_prove(
&[sender_pre, recipient_pre],
&Program::serialize_instruction(balance_to_move).unwrap(),
&[1, 0],
&[new_nonce],
&[(sender_keys.npk(), sender_keys.ivk(), [3; 32])],
&[(sender_keys.npk(), shared_secret)],
&[(
sender_keys.nsk,
state
@ -907,14 +918,12 @@ pub mod tests {
)
.unwrap();
let message = Message::new(
let message = Message::try_from_circuit_output(
vec![recipient_address.clone()],
vec![],
output.public_post_states,
output.encrypted_private_post_states,
output.new_commitments.clone(),
output.new_nullifiers,
);
vec![epk],
output,
).unwrap();
let witness_set = WitnessSet::for_message(&message, proof, &[]);