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|
use serde::{Deserialize, Serialize};
use onioncoin_timing::TimingMetadata;
/// Transaction ID (hash of transaction)
pub type TxId = [u8; 32];
/// A transaction in the OnionCoin network
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Transaction {
/// Protocol version
pub version: u8,
/// Transaction inputs
pub inputs: Vec<TransactionInput>,
/// Transaction outputs
pub outputs: Vec<TransactionOutput>,
/// Ring signatures for anonymity (simplified placeholder)
pub ring_signatures: Vec<RingSignature>,
/// Range proof to hide amounts (placeholder)
pub range_proof: Vec<u8>,
/// Encrypted transaction fee
pub encrypted_fee: u64,
/// Timing metadata for temporal privacy
pub timing: TimingMetadata,
}
impl Transaction {
/// Calculate transaction ID (hash)
pub fn id(&self) -> TxId {
let serialized = bincode::serialize(self).expect("Serialization should not fail");
let hash = blake3::hash(&serialized);
*hash.as_bytes()
}
/// Validate transaction structure
pub fn validate(&self) -> Result<(), TransactionError> {
// Must have at least one input and one output
if self.inputs.is_empty() {
return Err(TransactionError::NoInputs);
}
if self.outputs.is_empty() {
return Err(TransactionError::NoOutputs);
}
// Ring signatures must match inputs
if self.ring_signatures.len() != self.inputs.len() {
return Err(TransactionError::InvalidRingSignatures);
}
// Validate timing metadata
if !self.timing.validate(chrono::Utc::now()) {
return Err(TransactionError::InvalidTimingMetadata);
}
Ok(())
}
/// Get size in bytes
pub fn size(&self) -> usize {
bincode::serialize(self)
.map(|s| s.len())
.unwrap_or(0)
}
}
/// Transaction input
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
pub struct TransactionInput {
/// Reference to previous transaction output
pub previous_output: OutPoint,
/// Key image (prevents double spending in ring signatures)
pub key_image: [u8; 32],
}
/// Reference to a specific output in a previous transaction
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
pub struct OutPoint {
/// Transaction ID
pub txid: TxId,
/// Output index
pub vout: u32,
}
/// Transaction output
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
pub struct TransactionOutput {
/// Encrypted amount (confidential transaction)
pub encrypted_amount: Vec<u8>,
/// One-time stealth address (public key)
pub stealth_address: [u8; 32],
/// Commitment to the amount (for verification)
pub commitment: [u8; 32],
}
/// Ring signature for input anonymity
/// Simplified placeholder - production would use actual cryptographic implementation
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct RingSignature {
/// Public keys in the ring (decoy outputs + real output)
pub ring: Vec<[u8; 32]>,
/// Signature components
pub c: [u8; 32],
pub r: Vec<[u8; 32]>,
/// Ring size (typically 11 for privacy)
pub ring_size: usize,
}
impl RingSignature {
/// Create a new ring signature with specified ring size
pub fn new(ring_size: usize) -> Self {
Self {
ring: vec![[0u8; 32]; ring_size],
c: [0u8; 32],
r: vec![[0u8; 32]; ring_size],
ring_size,
}
}
/// Verify ring signature (placeholder)
pub fn verify(&self) -> bool {
// In production: actual ring signature verification
self.ring.len() == self.ring_size && self.r.len() == self.ring_size
}
}
#[derive(Debug, thiserror::Error)]
pub enum TransactionError {
#[error("Transaction has no inputs")]
NoInputs,
#[error("Transaction has no outputs")]
NoOutputs,
#[error("Invalid ring signatures")]
InvalidRingSignatures,
#[error("Invalid timing metadata")]
InvalidTimingMetadata,
#[error("Transaction too large")]
TooLarge,
#[error("Invalid fee")]
InvalidFee,
}
#[cfg(test)]
mod tests {
use super::*;
use chrono::Utc;
fn create_test_transaction() -> Transaction {
let seed = [42u8; 32];
let timing = TimingMetadata::new(Utc::now(), &seed).unwrap();
Transaction {
version: 1,
inputs: vec![TransactionInput {
previous_output: OutPoint {
txid: [1u8; 32],
vout: 0,
},
key_image: [2u8; 32],
}],
outputs: vec![TransactionOutput {
encrypted_amount: vec![0u8; 32],
stealth_address: [3u8; 32],
commitment: [4u8; 32],
}],
ring_signatures: vec![RingSignature::new(11)],
range_proof: vec![0u8; 64],
encrypted_fee: 1000,
timing,
}
}
#[test]
fn test_transaction_id() {
let tx1 = create_test_transaction();
let tx2 = create_test_transaction();
// Same transaction should have same ID
assert_eq!(tx1.id(), tx2.id());
}
#[test]
fn test_transaction_validation() {
let tx = create_test_transaction();
assert!(tx.validate().is_ok());
}
#[test]
fn test_transaction_no_inputs() {
let mut tx = create_test_transaction();
tx.inputs.clear();
assert!(matches!(
tx.validate(),
Err(TransactionError::NoInputs)
));
}
#[test]
fn test_transaction_no_outputs() {
let mut tx = create_test_transaction();
tx.outputs.clear();
assert!(matches!(
tx.validate(),
Err(TransactionError::NoOutputs)
));
}
#[test]
fn test_ring_signature_verification() {
let ring_sig = RingSignature::new(11);
assert!(ring_sig.verify());
}
}
|
