Files
pirate-librustzcash/zcash_primitives/src/transaction/components.rs
2019-10-15 17:47:53 +13:00

421 lines
14 KiB
Rust

//! Structs representing the components within Zcash transactions.
use crate::jubjub::{edwards, Unknown};
use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt};
use ff::{PrimeField, PrimeFieldRepr};
use pairing::bls12_381::{Bls12, Fr, FrRepr};
use std::io::{self, Read, Write};
use crate::legacy::Script;
use crate::redjubjub::{PublicKey, Signature};
use crate::JUBJUB;
pub mod amount;
pub use self::amount::Amount;
// π_A + π_B + π_C
pub const GROTH_PROOF_SIZE: usize = (48 + 96 + 48);
// π_A + π_A' + π_B + π_B' + π_C + π_C' + π_K + π_H
const PHGR_PROOF_SIZE: usize = (33 + 33 + 65 + 33 + 33 + 33 + 33 + 33);
const ZC_NUM_JS_INPUTS: usize = 2;
const ZC_NUM_JS_OUTPUTS: usize = 2;
#[derive(Clone, Debug, PartialEq)]
pub struct OutPoint {
hash: [u8; 32],
n: u32,
}
impl OutPoint {
pub fn new(hash: [u8; 32], n: u32) -> Self {
OutPoint { hash, n }
}
pub fn read<R: Read>(mut reader: R) -> io::Result<Self> {
let mut hash = [0; 32];
reader.read_exact(&mut hash)?;
let n = reader.read_u32::<LittleEndian>()?;
Ok(OutPoint { hash, n })
}
pub fn write<W: Write>(&self, mut writer: W) -> io::Result<()> {
writer.write_all(&self.hash)?;
writer.write_u32::<LittleEndian>(self.n)
}
}
#[derive(Debug)]
pub struct TxIn {
pub prevout: OutPoint,
pub script_sig: Script,
pub sequence: u32,
}
impl TxIn {
#[cfg(feature = "transparent-inputs")]
pub fn new(prevout: OutPoint) -> Self {
TxIn {
prevout,
script_sig: Script::default(),
sequence: std::u32::MAX,
}
}
pub fn read<R: Read>(mut reader: &mut R) -> io::Result<Self> {
let prevout = OutPoint::read(&mut reader)?;
let script_sig = Script::read(&mut reader)?;
let sequence = reader.read_u32::<LittleEndian>()?;
Ok(TxIn {
prevout,
script_sig,
sequence,
})
}
pub fn write<W: Write>(&self, mut writer: W) -> io::Result<()> {
self.prevout.write(&mut writer)?;
self.script_sig.write(&mut writer)?;
writer.write_u32::<LittleEndian>(self.sequence)
}
}
#[derive(Clone, Debug)]
pub struct TxOut {
pub value: Amount,
pub script_pubkey: Script,
}
impl TxOut {
pub fn read<R: Read>(mut reader: &mut R) -> io::Result<Self> {
let value = {
let mut tmp = [0; 8];
reader.read_exact(&mut tmp)?;
Amount::from_nonnegative_i64_le_bytes(tmp)
}
.map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "value out of range"))?;
let script_pubkey = Script::read(&mut reader)?;
Ok(TxOut {
value,
script_pubkey,
})
}
pub fn write<W: Write>(&self, mut writer: W) -> io::Result<()> {
writer.write_all(&self.value.to_i64_le_bytes())?;
self.script_pubkey.write(&mut writer)
}
}
pub struct SpendDescription {
pub cv: edwards::Point<Bls12, Unknown>,
pub anchor: Fr,
pub nullifier: [u8; 32],
pub rk: PublicKey<Bls12>,
pub zkproof: [u8; GROTH_PROOF_SIZE],
pub spend_auth_sig: Option<Signature>,
}
impl std::fmt::Debug for SpendDescription {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> Result<(), std::fmt::Error> {
write!(
f,
"SpendDescription(cv = {:?}, anchor = {:?}, nullifier = {:?}, rk = {:?}, spend_auth_sig = {:?})",
self.cv, self.anchor, self.nullifier, self.rk, self.spend_auth_sig
)
}
}
impl SpendDescription {
pub fn read<R: Read>(mut reader: &mut R) -> io::Result<Self> {
// Consensus rules (§4.4):
// - Canonical encoding is enforced here.
// - "Not small order" is enforced in SaplingVerificationContext::check_spend()
// (located in zcash_proofs::sapling::verifier).
let cv = edwards::Point::<Bls12, Unknown>::read(&mut reader, &JUBJUB)?;
// Consensus rule (§7.3): Canonical encoding is enforced here
let anchor = {
let mut f = FrRepr::default();
f.read_le(&mut reader)?;
Fr::from_repr(f).map_err(|e| io::Error::new(io::ErrorKind::InvalidInput, e))?
};
let mut nullifier = [0; 32];
reader.read_exact(&mut nullifier)?;
// Consensus rules (§4.4):
// - Canonical encoding is enforced here.
// - "Not small order" is enforced in SaplingVerificationContext::check_spend()
let rk = PublicKey::<Bls12>::read(&mut reader, &JUBJUB)?;
// Consensus rules (§4.4):
// - Canonical encoding is enforced by the API of SaplingVerificationContext::check_spend()
// due to the need to parse this into a bellman::groth16::Proof.
// - Proof validity is enforced in SaplingVerificationContext::check_spend()
let mut zkproof = [0; GROTH_PROOF_SIZE];
reader.read_exact(&mut zkproof)?;
// Consensus rules (§4.4):
// - Canonical encoding is enforced here.
// - Signature validity is enforced in SaplingVerificationContext::check_spend()
let spend_auth_sig = Some(Signature::read(&mut reader)?);
Ok(SpendDescription {
cv,
anchor,
nullifier,
rk,
zkproof,
spend_auth_sig,
})
}
pub fn write<W: Write>(&self, mut writer: W) -> io::Result<()> {
self.cv.write(&mut writer)?;
self.anchor.into_repr().write_le(&mut writer)?;
writer.write_all(&self.nullifier)?;
self.rk.write(&mut writer)?;
writer.write_all(&self.zkproof)?;
match self.spend_auth_sig {
Some(sig) => sig.write(&mut writer),
None => Err(io::Error::new(
io::ErrorKind::InvalidInput,
"Missing spend auth signature",
)),
}
}
}
pub struct OutputDescription {
pub cv: edwards::Point<Bls12, Unknown>,
pub cmu: Fr,
pub ephemeral_key: edwards::Point<Bls12, Unknown>,
pub enc_ciphertext: [u8; 580],
pub out_ciphertext: [u8; 80],
pub zkproof: [u8; GROTH_PROOF_SIZE],
}
impl std::fmt::Debug for OutputDescription {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> Result<(), std::fmt::Error> {
write!(
f,
"OutputDescription(cv = {:?}, cmu = {:?}, ephemeral_key = {:?})",
self.cv, self.cmu, self.ephemeral_key
)
}
}
impl OutputDescription {
pub fn read<R: Read>(mut reader: &mut R) -> io::Result<Self> {
// Consensus rules (§4.5):
// - Canonical encoding is enforced here.
// - "Not small order" is enforced in SaplingVerificationContext::check_output()
// (located in zcash_proofs::sapling::verifier).
let cv = edwards::Point::<Bls12, Unknown>::read(&mut reader, &JUBJUB)?;
// Consensus rule (§7.4): Canonical encoding is enforced here
let cmu = {
let mut f = FrRepr::default();
f.read_le(&mut reader)?;
Fr::from_repr(f).map_err(|e| io::Error::new(io::ErrorKind::InvalidInput, e))?
};
// Consensus rules (§4.5):
// - Canonical encoding is enforced here.
// - "Not small order" is enforced in SaplingVerificationContext::check_output()
let ephemeral_key = edwards::Point::<Bls12, Unknown>::read(&mut reader, &JUBJUB)?;
let mut enc_ciphertext = [0; 580];
let mut out_ciphertext = [0; 80];
reader.read_exact(&mut enc_ciphertext)?;
reader.read_exact(&mut out_ciphertext)?;
// Consensus rules (§4.5):
// - Canonical encoding is enforced by the API of SaplingVerificationContext::check_output()
// due to the need to parse this into a bellman::groth16::Proof.
// - Proof validity is enforced in SaplingVerificationContext::check_output()
let mut zkproof = [0; GROTH_PROOF_SIZE];
reader.read_exact(&mut zkproof)?;
Ok(OutputDescription {
cv,
cmu,
ephemeral_key,
enc_ciphertext,
out_ciphertext,
zkproof,
})
}
pub fn write<W: Write>(&self, mut writer: W) -> io::Result<()> {
self.cv.write(&mut writer)?;
self.cmu.into_repr().write_le(&mut writer)?;
self.ephemeral_key.write(&mut writer)?;
writer.write_all(&self.enc_ciphertext)?;
writer.write_all(&self.out_ciphertext)?;
writer.write_all(&self.zkproof)
}
}
enum SproutProof {
Groth([u8; GROTH_PROOF_SIZE]),
PHGR([u8; PHGR_PROOF_SIZE]),
}
impl std::fmt::Debug for SproutProof {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> Result<(), std::fmt::Error> {
match self {
SproutProof::Groth(_) => write!(f, "SproutProof::Groth"),
SproutProof::PHGR(_) => write!(f, "SproutProof::PHGR"),
}
}
}
pub struct JSDescription {
vpub_old: Amount,
vpub_new: Amount,
anchor: [u8; 32],
nullifiers: [[u8; 32]; ZC_NUM_JS_INPUTS],
commitments: [[u8; 32]; ZC_NUM_JS_OUTPUTS],
ephemeral_key: [u8; 32],
random_seed: [u8; 32],
macs: [[u8; 32]; ZC_NUM_JS_INPUTS],
proof: SproutProof,
ciphertexts: [[u8; 601]; ZC_NUM_JS_OUTPUTS],
}
impl std::fmt::Debug for JSDescription {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> Result<(), std::fmt::Error> {
write!(
f,
"JSDescription(
vpub_old = {:?}, vpub_new = {:?},
anchor = {:?},
nullifiers = {:?},
commitments = {:?},
ephemeral_key = {:?},
random_seed = {:?},
macs = {:?})",
self.vpub_old,
self.vpub_new,
self.anchor,
self.nullifiers,
self.commitments,
self.ephemeral_key,
self.random_seed,
self.macs
)
}
}
impl JSDescription {
pub fn read<R: Read>(mut reader: R, use_groth: bool) -> io::Result<Self> {
// Consensus rule (§4.3): Canonical encoding is enforced here
let vpub_old = {
let mut tmp = [0; 8];
reader.read_exact(&mut tmp)?;
Amount::from_u64_le_bytes(tmp)
}
.map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "vpub_old out of range"))?;
// Consensus rule (§4.3): Canonical encoding is enforced here
let vpub_new = {
let mut tmp = [0; 8];
reader.read_exact(&mut tmp)?;
Amount::from_u64_le_bytes(tmp)
}
.map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "vpub_new out of range"))?;
// Consensus rule (§4.3): One of vpub_old and vpub_new being zero is
// enforced by CheckTransactionWithoutProofVerification() in zcashd.
let mut anchor = [0; 32];
reader.read_exact(&mut anchor)?;
let mut nullifiers = [[0; 32]; ZC_NUM_JS_INPUTS];
nullifiers
.iter_mut()
.map(|nf| reader.read_exact(nf))
.collect::<io::Result<()>>()?;
let mut commitments = [[0; 32]; ZC_NUM_JS_OUTPUTS];
commitments
.iter_mut()
.map(|cm| reader.read_exact(cm))
.collect::<io::Result<()>>()?;
// Consensus rule (§4.3): Canonical encoding is enforced by
// ZCNoteDecryption::decrypt() in zcashd
let mut ephemeral_key = [0; 32];
reader.read_exact(&mut ephemeral_key)?;
let mut random_seed = [0; 32];
reader.read_exact(&mut random_seed)?;
let mut macs = [[0; 32]; ZC_NUM_JS_INPUTS];
macs.iter_mut()
.map(|mac| reader.read_exact(mac))
.collect::<io::Result<()>>()?;
let proof = if use_groth {
// Consensus rules (§4.3):
// - Canonical encoding is enforced in librustzcash_sprout_verify()
// - Proof validity is enforced in librustzcash_sprout_verify()
let mut proof = [0; GROTH_PROOF_SIZE];
reader.read_exact(&mut proof)?;
SproutProof::Groth(proof)
} else {
// Consensus rules (§4.3):
// - Canonical encoding is enforced by PHGRProof in zcashd
// - Proof validity is enforced by JSDescription::Verify() in zcashd
let mut proof = [0; PHGR_PROOF_SIZE];
reader.read_exact(&mut proof)?;
SproutProof::PHGR(proof)
};
let mut ciphertexts = [[0; 601]; ZC_NUM_JS_OUTPUTS];
ciphertexts
.iter_mut()
.map(|ct| reader.read_exact(ct))
.collect::<io::Result<()>>()?;
Ok(JSDescription {
vpub_old,
vpub_new,
anchor,
nullifiers,
commitments,
ephemeral_key,
random_seed,
macs,
proof,
ciphertexts,
})
}
pub fn write<W: Write>(&self, mut writer: W) -> io::Result<()> {
writer.write_all(&self.vpub_old.to_i64_le_bytes())?;
writer.write_all(&self.vpub_new.to_i64_le_bytes())?;
writer.write_all(&self.anchor)?;
writer.write_all(&self.nullifiers[0])?;
writer.write_all(&self.nullifiers[1])?;
writer.write_all(&self.commitments[0])?;
writer.write_all(&self.commitments[1])?;
writer.write_all(&self.ephemeral_key)?;
writer.write_all(&self.random_seed)?;
writer.write_all(&self.macs[0])?;
writer.write_all(&self.macs[1])?;
match &self.proof {
SproutProof::Groth(p) => writer.write_all(p)?,
SproutProof::PHGR(p) => writer.write_all(p)?,
}
writer.write_all(&self.ciphertexts[0])?;
writer.write_all(&self.ciphertexts[1])
}
}