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librustzcash
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Document enforcement of consensus rules on transaction components

This commit is contained in:
Jack Grigg 2018-11-30 22:59:48 +00:00
parent d707ebd321
commit 7ff32b04d6
No known key found for this signature in database
GPG Key ID: 1B8D649257DB0829
1 changed files with 47 additions and 1 deletions
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48
zcash_primitives/src/transaction/components.rs
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@ -147,7 +147,13 @@ pub struct SpendDescription {
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)?;
@ -157,10 +163,21 @@ impl SpendDescription {
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 = Signature::read(&mut reader)?;
Ok(SpendDescription {
@ -194,12 +211,22 @@ pub struct OutputDescription {
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];
@ -207,6 +234,10 @@ impl OutputDescription {
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)?;
@ -250,9 +281,15 @@ pub struct JSDescription {
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 = Amount::read_u64(&mut reader)?;
// Consensus rule (§4.3): Canonical encoding is enforced here
let vpub_new = Amount::read_u64(&mut reader)?;
// 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)?;
@ -268,9 +305,12 @@ impl JSDescription {
.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];
let mut random_seed = [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];
@ -280,11 +320,17 @@ impl JSDescription {
let proof = match use_groth {
true => {
// 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)
}
false => {
// 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)