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Merge pull request #358 from nuttycom/refactor/component_modules_2 

Generalize Sapling note encryption to allow reuse with Orchard notes.
This commit is contained in:
str4d 2021-04-16 04:17:57 +01:00 committed by GitHub
parent 1b4aab0b76 28a45028ab
commit 3b02c8b26e
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
18 changed files with 2034 additions and 1863 deletions
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12
components/zcash_note_encryption/Cargo.toml
View File

@ -4,6 +4,7 @@ description = "TBD"
version = "0.0.0"
authors = [
"Jack Grigg <jack@electriccoin.co>",
"Kris Nuttycombe <kris@electriccoin.co>"
]
homepage = "https://github.com/zcash/librustzcash"
repository = "https://github.com/zcash/librustzcash"
@ -11,3 +12,14 @@ license = "MIT OR Apache-2.0"
edition = "2018"
[dependencies]
blake2b_simd = "0.5"
byteorder = "1"
crypto_api_chachapoly = "0.4"
ff = "0.8"
group = "0.8"
rand_core = "0.5.1"
subtle = "2.2.3"
[dev-dependencies]
zcash_primitives = { version = "0.5", path = "../../zcash_primitives" }
jubjub = "0.5.1"

504
components/zcash_note_encryption/src/lib.rs
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@ -1,8 +1,500 @@
#[cfg(test)]
mod tests {
#[allow(clippy::eq_op)]
#[test]
fn it_works() {
assert_eq!(2 + 2, 4);
//! Implementation of in-band secret distribution abstractions
//! for Zcash transactions. The implementations here provide
//! functionality that is shared between the Sapling and Orchard
//! protocols.
use crypto_api_chachapoly::{ChaCha20Ietf, ChachaPolyIetf};
use rand_core::RngCore;
use std::convert::TryFrom;
use subtle::{Choice, ConstantTimeEq};
pub const COMPACT_NOTE_SIZE: usize = 1 + // version
11 + // diversifier
8 + // value
32; // rseed (or rcm prior to ZIP 212)
pub const NOTE_PLAINTEXT_SIZE: usize = COMPACT_NOTE_SIZE + 512;
pub const OUT_PLAINTEXT_SIZE: usize = 32 + // pk_d
32; // esk
pub const AEAD_TAG_SIZE: usize = 16;
pub const ENC_CIPHERTEXT_SIZE: usize = NOTE_PLAINTEXT_SIZE + AEAD_TAG_SIZE;
pub const OUT_CIPHERTEXT_SIZE: usize = OUT_PLAINTEXT_SIZE + AEAD_TAG_SIZE;
/// A symmetric key that can be used to recover a single Sapling or Orchard output.
pub struct OutgoingCipherKey(pub [u8; 32]);
impl From<[u8; 32]> for OutgoingCipherKey {
fn from(ock: [u8; 32]) -> Self {
OutgoingCipherKey(ock)
}
}
impl AsRef<[u8]> for OutgoingCipherKey {
fn as_ref(&self) -> &[u8] {
&self.0
}
}
pub struct EphemeralKeyBytes(pub [u8; 32]);
impl AsRef<[u8]> for EphemeralKeyBytes {
fn as_ref(&self) -> &[u8] {
&self.0
}
}
impl From<[u8; 32]> for EphemeralKeyBytes {
fn from(value: [u8; 32]) -> EphemeralKeyBytes {
EphemeralKeyBytes(value)
}
}
impl ConstantTimeEq for EphemeralKeyBytes {
fn ct_eq(&self, other: &Self) -> Choice {
self.0.ct_eq(&other.0)
}
}
pub struct NotePlaintextBytes(pub [u8; NOTE_PLAINTEXT_SIZE]);
pub struct OutPlaintextBytes(pub [u8; OUT_PLAINTEXT_SIZE]);
#[derive(Copy, Clone, PartialEq, Eq)]
pub enum NoteValidity {
Valid,
Invalid,
}
pub trait Domain {
type EphemeralSecretKey;
type EphemeralPublicKey;
type SharedSecret;
type SymmetricKey: AsRef<[u8]>;
type Note;
type Recipient;
type DiversifiedTransmissionKey;
type IncomingViewingKey;
type OutgoingViewingKey;
type ValueCommitment;
type ExtractedCommitment;
type ExtractedCommitmentBytes: Eq + TryFrom<Self::ExtractedCommitment>;
type Memo;
fn derive_esk(note: &Self::Note) -> Option<Self::EphemeralSecretKey>;
fn get_pk_d(note: &Self::Note) -> Self::DiversifiedTransmissionKey;
fn ka_derive_public(
note: &Self::Note,
esk: &Self::EphemeralSecretKey,
) -> Self::EphemeralPublicKey;
fn ka_agree_enc(
esk: &Self::EphemeralSecretKey,
pk_d: &Self::DiversifiedTransmissionKey,
) -> Self::SharedSecret;
fn ka_agree_dec(
ivk: &Self::IncomingViewingKey,
epk: &Self::EphemeralPublicKey,
) -> Self::SharedSecret;
fn kdf(secret: Self::SharedSecret, ephemeral_key: &EphemeralKeyBytes) -> Self::SymmetricKey;
// for right now, we just need `recipient` to get `d`; in the future when we
// can get that from a Sapling note, the recipient parameter will be able
// to be removed.
fn note_plaintext_bytes(
note: &Self::Note,
recipient: &Self::Recipient,
memo: &Self::Memo,
) -> NotePlaintextBytes;
fn derive_ock(
ovk: &Self::OutgoingViewingKey,
cv: &Self::ValueCommitment,
cmstar: &Self::ExtractedCommitment,
ephemeral_key: &EphemeralKeyBytes,
) -> OutgoingCipherKey;
fn outgoing_plaintext_bytes(
note: &Self::Note,
esk: &Self::EphemeralSecretKey,
) -> OutPlaintextBytes;
fn epk_bytes(epk: &Self::EphemeralPublicKey) -> EphemeralKeyBytes;
fn check_epk_bytes<F: Fn(&Self::EphemeralSecretKey) -> NoteValidity>(
note: &Self::Note,
check: F,
) -> NoteValidity;
fn cmstar(note: &Self::Note) -> Self::ExtractedCommitment;
fn parse_note_plaintext_without_memo_ivk(
&self,
ivk: &Self::IncomingViewingKey,
plaintext: &[u8],
) -> Option<(Self::Note, Self::Recipient)>;
fn parse_note_plaintext_without_memo_ovk(
&self,
pk_d: &Self::DiversifiedTransmissionKey,
esk: &Self::EphemeralSecretKey,
epk: &Self::EphemeralPublicKey,
plaintext: &[u8],
) -> Option<(Self::Note, Self::Recipient)>;
// &self is passed here in anticipation of future changes
// to memo handling where the memos may no longer be
// part of the note plaintext.
fn extract_memo(&self, plaintext: &[u8]) -> Self::Memo;
fn extract_pk_d(
out_plaintext: &[u8; OUT_CIPHERTEXT_SIZE],
) -> Option<Self::DiversifiedTransmissionKey>;
fn extract_esk(out_plaintext: &[u8; OUT_CIPHERTEXT_SIZE]) -> Option<Self::EphemeralSecretKey>;
}
pub trait ShieldedOutput<D: Domain> {
fn epk(&self) -> &D::EphemeralPublicKey;
fn cmstar_bytes(&self) -> D::ExtractedCommitmentBytes;
fn enc_ciphertext(&self) -> &[u8];
}
/// A struct containing context required for encrypting Sapling and Orchard notes.
///
/// This struct provides a safe API for encrypting Sapling and Orchard notes. In particular, it
/// enforces that fresh ephemeral keys are used for every note, and that the ciphertexts are
/// consistent with each other.
///
/// Implements section 4.19 of the
/// [Zcash Protocol Specification](https://zips.z.cash/protocol/nu5.pdf#saplingandorchardinband)
/// NB: the example code is only covering the post-Canopy case.
///
/// # Examples
///
/// ```
/// extern crate ff;
/// extern crate rand_core;
/// extern crate zcash_primitives;
///
/// use ff::Field;
/// use rand_core::OsRng;
/// use zcash_primitives::{
/// consensus::{TEST_NETWORK, TestNetwork, NetworkUpgrade, Parameters},
/// memo::MemoBytes,
/// sapling::{
/// keys::{OutgoingViewingKey, prf_expand},
/// note_encryption::sapling_note_encryption,
/// util::generate_random_rseed,
/// Diversifier, PaymentAddress, Rseed, ValueCommitment
/// },
/// };
///
/// let mut rng = OsRng;
///
/// let diversifier = Diversifier([0; 11]);
/// let pk_d = diversifier.g_d().unwrap();
/// let to = PaymentAddress::from_parts(diversifier, pk_d).unwrap();
/// let ovk = Some(OutgoingViewingKey([0; 32]));
///
/// let value = 1000;
/// let rcv = jubjub::Fr::random(&mut rng);
/// let cv = ValueCommitment {
/// value,
/// randomness: rcv.clone(),
/// };
/// let height = TEST_NETWORK.activation_height(NetworkUpgrade::Canopy).unwrap();
/// let rseed = generate_random_rseed(&TEST_NETWORK, height, &mut rng);
/// let note = to.create_note(value, rseed).unwrap();
/// let cmu = note.cmu();
///
/// let mut enc = sapling_note_encryption::<_, TestNetwork>(ovk, note, to, MemoBytes::empty(), &mut rng);
/// let encCiphertext = enc.encrypt_note_plaintext();
/// let outCiphertext = enc.encrypt_outgoing_plaintext(&cv.commitment().into(), &cmu, &mut rng);
/// ```
pub struct NoteEncryption<D: Domain> {
epk: D::EphemeralPublicKey,
esk: D::EphemeralSecretKey,
note: D::Note,
to: D::Recipient,
memo: D::Memo,
/// `None` represents the `ovk = ⊥` case.
ovk: Option<D::OutgoingViewingKey>,
}
impl<D: Domain> NoteEncryption<D> {
/// Construct a new note encryption context for the specified note,
/// recipient, and memo.
pub fn new(
ovk: Option<D::OutgoingViewingKey>,
note: D::Note,
to: D::Recipient,
memo: D::Memo,
) -> Self {
let esk = D::derive_esk(&note).expect("ZIP 212 is active.");
Self::new_with_esk(esk, ovk, note, to, memo)
}
/// For use only with Sapling. This method is preserved in order that test code
/// be able to generate pre-ZIP-212 ciphertexts so that tests can continue to
/// cover pre-ZIP-212 transaction decryption.
pub fn new_with_esk(
esk: D::EphemeralSecretKey,
ovk: Option<D::OutgoingViewingKey>,
note: D::Note,
to: D::Recipient,
memo: D::Memo,
) -> Self {
NoteEncryption {
epk: D::ka_derive_public(&note, &esk),
esk,
note,
to,
memo,
ovk,
}
}
/// Exposes the ephemeral secret key being used to encrypt this note.
pub fn esk(&self) -> &D::EphemeralSecretKey {
&self.esk
}
/// Exposes the encoding of the ephemeral public key being used to encrypt this note.
pub fn epk(&self) -> &D::EphemeralPublicKey {
&self.epk
}
/// Generates `encCiphertext` for this note.
pub fn encrypt_note_plaintext(&self) -> [u8; ENC_CIPHERTEXT_SIZE] {
let pk_d = D::get_pk_d(&self.note);
let shared_secret = D::ka_agree_enc(&self.esk, &pk_d);
let key = D::kdf(shared_secret, &D::epk_bytes(&self.epk));
let input = D::note_plaintext_bytes(&self.note, &self.to, &self.memo);
let mut output = [0u8; ENC_CIPHERTEXT_SIZE];
assert_eq!(
ChachaPolyIetf::aead_cipher()
.seal_to(&mut output, &input.0, &[], key.as_ref(), &[0u8; 12])
.unwrap(),
ENC_CIPHERTEXT_SIZE
);
output
}
/// Generates `outCiphertext` for this note.
pub fn encrypt_outgoing_plaintext<R: RngCore>(
&self,
cv: &D::ValueCommitment,
cmstar: &D::ExtractedCommitment,
rng: &mut R,
) -> [u8; OUT_CIPHERTEXT_SIZE] {
let (ock, input) = if let Some(ovk) = &self.ovk {
let ock = D::derive_ock(ovk, &cv, &cmstar, &D::epk_bytes(&self.epk));
let input = D::outgoing_plaintext_bytes(&self.note, &self.esk);
(ock, input)
} else {
// ovk = ⊥
let mut ock = OutgoingCipherKey([0; 32]);
let mut input = [0u8; OUT_PLAINTEXT_SIZE];
rng.fill_bytes(&mut ock.0);
rng.fill_bytes(&mut input);
(ock, OutPlaintextBytes(input))
};
let mut output = [0u8; OUT_CIPHERTEXT_SIZE];
assert_eq!(
ChachaPolyIetf::aead_cipher()
.seal_to(&mut output, &input.0, &[], ock.as_ref(), &[0u8; 12])
.unwrap(),
OUT_CIPHERTEXT_SIZE
);
output
}
}
/// Trial decryption of the full note plaintext by the recipient.
///
/// Attempts to decrypt and validate the given `enc_ciphertext` using the given `ivk`.
/// If successful, the corresponding Sapling note and memo are returned, along with the
/// `PaymentAddress` to which the note was sent.
///
/// Implements section 4.19.2 of the
/// [Zcash Protocol Specification](https://zips.z.cash/protocol/nu5.pdf#decryptivk)
pub fn try_note_decryption<D: Domain, Output: ShieldedOutput<D>>(
domain: &D,
ivk: &D::IncomingViewingKey,
output: &Output,
) -> Option<(D::Note, D::Recipient, D::Memo)> {
assert_eq!(output.enc_ciphertext().len(), ENC_CIPHERTEXT_SIZE);
let shared_secret = D::ka_agree_dec(ivk, output.epk());
let key = D::kdf(shared_secret, &D::epk_bytes(output.epk()));
let mut plaintext = [0; ENC_CIPHERTEXT_SIZE];
assert_eq!(
ChachaPolyIetf::aead_cipher()
.open_to(
&mut plaintext,
output.enc_ciphertext(),
&[],
key.as_ref(),
&[0u8; 12]
)
.ok()?,
NOTE_PLAINTEXT_SIZE
);
let (note, to) = parse_note_plaintext_without_memo_ivk(
domain,
ivk,
output.epk(),
&output.cmstar_bytes(),
&plaintext,
)?;
let memo = domain.extract_memo(&plaintext);
Some((note, to, memo))
}
fn parse_note_plaintext_without_memo_ivk<D: Domain>(
domain: &D,
ivk: &D::IncomingViewingKey,
epk: &D::EphemeralPublicKey,
cmstar_bytes: &D::ExtractedCommitmentBytes,
plaintext: &[u8],
) -> Option<(D::Note, D::Recipient)> {
let (note, to) = domain.parse_note_plaintext_without_memo_ivk(ivk, &plaintext)?;
if let NoteValidity::Valid = check_note_validity::<D>(&note, epk, cmstar_bytes) {
Some((note, to))
} else {
None
}
}
fn check_note_validity<D: Domain>(
note: &D::Note,
epk: &D::EphemeralPublicKey,
cmstar_bytes: &D::ExtractedCommitmentBytes,
) -> NoteValidity {
if D::ExtractedCommitmentBytes::try_from(D::cmstar(&note))
.map_or(false, |cs| &cs == cmstar_bytes)
{
let epk_bytes = D::epk_bytes(epk);
D::check_epk_bytes(&note, |derived_esk| {
if D::epk_bytes(&D::ka_derive_public(&note, &derived_esk))
.ct_eq(&epk_bytes)
.into()
{
NoteValidity::Valid
} else {
NoteValidity::Invalid
}
})
} else {
// Published commitment doesn't match calculated commitment
NoteValidity::Invalid
}
}
/// Trial decryption of the compact note plaintext by the recipient for light clients.
///
/// Attempts to decrypt and validate the first 52 bytes of `enc_ciphertext` using the
/// given `ivk`. If successful, the corresponding Sapling note is returned, along with the
/// `PaymentAddress` to which the note was sent.
///
/// Implements the procedure specified in [`ZIP 307`].
///
/// [`ZIP 307`]: https://zips.z.cash/zip-0307
pub fn try_compact_note_decryption<D: Domain, Output: ShieldedOutput<D>>(
domain: &D,
ivk: &D::IncomingViewingKey,
output: &Output,
) -> Option<(D::Note, D::Recipient)> {
assert_eq!(output.enc_ciphertext().len(), COMPACT_NOTE_SIZE);
let shared_secret = D::ka_agree_dec(&ivk, output.epk());
let key = D::kdf(shared_secret, &D::epk_bytes(output.epk()));
// Start from block 1 to skip over Poly1305 keying output
let mut plaintext = [0; COMPACT_NOTE_SIZE];
plaintext.copy_from_slice(output.enc_ciphertext());
ChaCha20Ietf::xor(key.as_ref(), &[0u8; 12], 1, &mut plaintext);
parse_note_plaintext_without_memo_ivk(
domain,
ivk,
output.epk(),
&output.cmstar_bytes(),
&plaintext,
)
}
/// Recovery of the full note plaintext by the sender.
///
/// Attempts to decrypt and validate the given `enc_ciphertext` using the given `ock`.
/// If successful, the corresponding Sapling note and memo are returned, along with the
/// `PaymentAddress` to which the note was sent.
///
/// Implements part of section 4.19.3 of the
/// [Zcash Protocol Specification](https://zips.z.cash/protocol/nu5.pdf#decryptovk)
/// For decryption using a Full Viewing Key see [`try_sapling_output_recovery`].
pub fn try_output_recovery_with_ock<D: Domain, Output: ShieldedOutput<D>>(
domain: &D,
ock: &OutgoingCipherKey,
output: &Output,
out_ciphertext: &[u8],
) -> Option<(D::Note, D::Recipient, D::Memo)> {
assert_eq!(output.enc_ciphertext().len(), ENC_CIPHERTEXT_SIZE);
assert_eq!(out_ciphertext.len(), OUT_CIPHERTEXT_SIZE);
let mut op = [0; OUT_CIPHERTEXT_SIZE];
assert_eq!(
ChachaPolyIetf::aead_cipher()
.open_to(&mut op, &out_ciphertext, &[], ock.as_ref(), &[0u8; 12])
.ok()?,
OUT_PLAINTEXT_SIZE
);
let pk_d = D::extract_pk_d(&op)?;
let esk = D::extract_esk(&op)?;
let shared_secret = D::ka_agree_enc(&esk, &pk_d);
// The small-order point check at the point of output parsing rejects
// non-canonical encodings, so reencoding here for the KDF should
// be okay.
let key = D::kdf(shared_secret, &D::epk_bytes(output.epk()));
let mut plaintext = [0; ENC_CIPHERTEXT_SIZE];
assert_eq!(
ChachaPolyIetf::aead_cipher()
.open_to(
&mut plaintext,
output.enc_ciphertext(),
&[],
key.as_ref(),
&[0u8; 12]
)
.ok()?,
NOTE_PLAINTEXT_SIZE
);
let (note, to) =
domain.parse_note_plaintext_without_memo_ovk(&pk_d, &esk, output.epk(), &plaintext)?;
let memo = domain.extract_memo(&plaintext);
if let NoteValidity::Valid =
check_note_validity::<D>(&note, output.epk(), &output.cmstar_bytes())
{
Some((note, to, memo))
} else {
None
}
}

6
zcash_client_backend/Cargo.toml
View File

@ -4,6 +4,7 @@ description = "APIs for creating shielded Zcash light clients"
version = "0.5.0"
authors = [
"Jack Grigg <jack@z.cash>",
"Kris Nuttycombe <kris@electriccoin.co>"
]
homepage = "https://github.com/zcash/librustzcash"
repository = "https://github.com/zcash/librustzcash"
@ -21,13 +22,14 @@ group = "0.8"
hex = "0.4"
jubjub = "0.5.1"
nom = "6.1"
percent-encoding = "2.1.0"
proptest = { version = "0.10.1", optional = true }
protobuf = "2.20"
rand_core = "0.5.1"
subtle = "2.2.3"
time = "0.2"
zcash_note_encryption = { version = "0.0", path = "../components/zcash_note_encryption" }
zcash_primitives = { version = "0.5", path = "../zcash_primitives" }
proptest = { version = "0.10.1", optional = true }
percent-encoding = "2.1.0"
[build-dependencies]
protobuf-codegen-pure = "2.20"

2
zcash_client_backend/src/data_api/wallet.rs
View File

@ -205,7 +205,7 @@ where
.unwrap(); //DiversifyHash would have to unexpectedly return the zero point for this to be None
let note = from
.create_note(u64::from(selected.note_value), selected.rseed)
.create_note(selected.note_value.into(), selected.rseed)
.unwrap();
let merkle_path = selected.witness.path().expect("the tree is not empty");

37
zcash_client_backend/src/decrypt.rs
View File

@ -3,8 +3,10 @@ use std::collections::HashMap;
use zcash_primitives::{
consensus::{self, BlockHeight},
memo::MemoBytes,
note_encryption::{try_sapling_note_decryption, try_sapling_output_recovery},
sapling::{Note, PaymentAddress},
sapling::{
note_encryption::{try_sapling_note_decryption, try_sapling_output_recovery},
Note, PaymentAddress,
},
transaction::Transaction,
zip32::ExtendedFullViewingKey,
};
@ -47,29 +49,14 @@ pub fn decrypt_transaction<P: consensus::Parameters>(
let ovk = extfvk.fvk.ovk;
for (index, output) in tx.shielded_outputs.iter().enumerate() {
let ((note, to, memo), outgoing) = match try_sapling_note_decryption(
params,
height,
&ivk,
&output.ephemeral_key,
&output.cmu,
&output.enc_ciphertext,
) {
Some(ret) => (ret, false),
None => match try_sapling_output_recovery(
params,
height,
&ovk,
&output.cv,
&output.cmu,
&output.ephemeral_key,
&output.enc_ciphertext,
&output.out_ciphertext,
) {
Some(ret) => (ret, true),
None => continue,
},
};
let ((note, to, memo), outgoing) =
match try_sapling_note_decryption(params, height, &ivk, output) {
Some(ret) => (ret, false),
None => match try_sapling_output_recovery(params, height, &ovk, output) {
Some(ret) => (ret, true),
None => continue,
},
};
decrypted.push(DecryptedOutput {
index,
note,

27
zcash_client_backend/src/proto.rs
View File

@ -2,14 +2,17 @@
use ff::PrimeField;
use group::GroupEncoding;
use std::convert::TryInto;
use std::convert::{TryFrom, TryInto};
use zcash_primitives::{
block::{BlockHash, BlockHeader},
consensus::BlockHeight,
sapling::Nullifier,
transaction::components::sapling::{CompactOutputDescription, OutputDescription},
};
use zcash_note_encryption::COMPACT_NOTE_SIZE;
pub mod compact_formats;
impl compact_formats::CompactBlock {
@ -98,6 +101,28 @@ impl compact_formats::CompactOutput {
}
}
impl From<OutputDescription> for compact_formats::CompactOutput {
fn from(out: OutputDescription) -> compact_formats::CompactOutput {
let mut result = compact_formats::CompactOutput::new();
result.set_cmu(out.cmu.to_repr().to_vec());
result.set_epk(out.ephemeral_key.to_bytes().to_vec());
result.set_ciphertext(out.enc_ciphertext[..COMPACT_NOTE_SIZE].to_vec());
result
}
}
impl TryFrom<compact_formats::CompactOutput> for CompactOutputDescription {
type Error = ();
fn try_from(value: compact_formats::CompactOutput) -> Result<Self, Self::Error> {
Ok(CompactOutputDescription {
cmu: value.cmu()?,
epk: value.epk()?,
enc_ciphertext: value.ciphertext,
})
}
}
impl compact_formats::CompactSpend {
pub fn nf(&self) -> Result<Nullifier, ()> {
Nullifier::from_slice(&self.nf).map_err(|_| ())

54
zcash_client_backend/src/welding_rig.rs
View File

@ -2,13 +2,17 @@
use ff::PrimeField;
use std::collections::HashSet;
use std::convert::TryFrom;
use subtle::{ConditionallySelectable, ConstantTimeEq, CtOption};
use zcash_note_encryption::ShieldedOutput;
use zcash_primitives::{
consensus::{self, BlockHeight},
merkle_tree::{CommitmentTree, IncrementalWitness},
note_encryption::try_sapling_compact_note_decryption,
sapling::{Node, Note, Nullifier, PaymentAddress, SaplingIvk},
transaction::TxId,
sapling::{
note_encryption::{try_sapling_compact_note_decryption, SaplingDomain},
Node, Note, Nullifier, PaymentAddress, SaplingIvk,
},
transaction::{components::sapling::CompactOutputDescription, TxId},
zip32::ExtendedFullViewingKey,
};
@ -36,12 +40,10 @@ fn scan_output<P: consensus::Parameters, K: ScanningKey>(
block_witnesses: &mut [&mut IncrementalWitness<Node>],
new_witnesses: &mut [&mut IncrementalWitness<Node>],
) -> Option<WalletShieldedOutput<K::Nf>> {
let cmu = output.cmu().ok()?;
let epk = output.epk().ok()?;
let ct = output.ciphertext;
let output = CompactOutputDescription::try_from(output).ok()?;
// Increment tree and witnesses
let node = Node::new(cmu.to_repr());
let node = Node::new(output.cmu.to_repr());
for witness in existing_witnesses {
witness.append(node).unwrap();
}
@ -54,7 +56,7 @@ fn scan_output<P: consensus::Parameters, K: ScanningKey>(
tree.append(node).unwrap();
for (account, vk) in vks.iter() {
let (note, to) = match vk.try_decryption(params, height, &epk, &cmu, &ct) {
let (note, to) = match vk.try_decryption(params, height, &output) {
Some(ret) => ret,
None => continue,
};
@ -72,8 +74,8 @@ fn scan_output<P: consensus::Parameters, K: ScanningKey>(
return Some(WalletShieldedOutput {
index,
cmu,
epk,
cmu: output.cmu,
epk: output.epk,
account: **account,
note,
to,
@ -106,13 +108,11 @@ pub trait ScanningKey {
/// Attempts to decrypt a Sapling note and payment address
/// from the specified ciphertext using this scanning key.
fn try_decryption<P: consensus::Parameters>(
fn try_decryption<P: consensus::Parameters, Output: ShieldedOutput<SaplingDomain<P>>>(
&self,
params: &P,
height: BlockHeight,
epk: &jubjub::ExtendedPoint,
cmu: &bls12_381::Scalar,
ct: &[u8],
output: &Output,
) -> Option<(Note, PaymentAddress)>;
/// Produces the nullifier for the specified note and witness, if possible.
@ -130,15 +130,13 @@ pub trait ScanningKey {
impl ScanningKey for ExtendedFullViewingKey {
type Nf = Nullifier;
fn try_decryption<P: consensus::Parameters>(
fn try_decryption<P: consensus::Parameters, Output: ShieldedOutput<SaplingDomain<P>>>(
&self,
params: &P,
height: BlockHeight,
epk: &jubjub::ExtendedPoint,
cmu: &bls12_381::Scalar,
ct: &[u8],
output: &Output,
) -> Option<(Note, PaymentAddress)> {
try_sapling_compact_note_decryption(params, height, &self.fvk.vk.ivk(), &epk, &cmu, &ct)
try_sapling_compact_note_decryption(params, height, &self.fvk.vk.ivk(), output)
}
fn nf(&self, note: &Note, witness: &IncrementalWitness<Node>) -> Self::Nf {
@ -153,15 +151,13 @@ impl ScanningKey for ExtendedFullViewingKey {
impl ScanningKey for SaplingIvk {
type Nf = ();
fn try_decryption<P: consensus::Parameters>(
fn try_decryption<P: consensus::Parameters, Output: ShieldedOutput<SaplingDomain<P>>>(
&self,
params: &P,
height: BlockHeight,
epk: &jubjub::ExtendedPoint,
cmu: &bls12_381::Scalar,
ct: &[u8],
output: &Output,
) -> Option<(Note, PaymentAddress)> {
try_sapling_compact_note_decryption(params, height, self, &epk, &cmu, &ct)
try_sapling_compact_note_decryption(params, height, self, output)
}
fn nf(&self, _note: &Note, _witness: &IncrementalWitness<Node>) {}
@ -305,8 +301,10 @@ mod tests {
constants::SPENDING_KEY_GENERATOR,
memo::MemoBytes,
merkle_tree::CommitmentTree,
note_encryption::SaplingNoteEncryption,
sapling::{util::generate_random_rseed, Note, Nullifier, SaplingIvk},
sapling::{
note_encryption::sapling_note_encryption, util::generate_random_rseed, Note, Nullifier,
SaplingIvk,
},
transaction::components::Amount,
zip32::{ExtendedFullViewingKey, ExtendedSpendingKey},
};
@ -368,7 +366,7 @@ mod tests {
value: value.into(),
rseed,
};
let encryptor = SaplingNoteEncryption::new(
let encryptor = sapling_note_encryption::<_, Network>(
Some(extfvk.fvk.ovk),
note.clone(),
to,
@ -395,7 +393,7 @@ mod tests {
let mut cout = CompactOutput::new();
cout.set_cmu(cmu);
cout.set_epk(epk);
cout.set_ciphertext(enc_ciphertext[..52].to_vec());
cout.set_ciphertext(enc_ciphertext.as_ref()[..52].to_vec());
let mut ctx = CompactTx::new();
let mut txid = vec![0; 32];
rng.fill_bytes(&mut txid);

1
zcash_client_sqlite/Cargo.toml
View File

@ -4,6 +4,7 @@ description = "An SQLite-based Zcash light client"
version = "0.3.0"
authors = [
"Jack Grigg <jack@z.cash>",
"Kris Nuttycombe <kris@electriccoin.co>"
]
homepage = "https://github.com/zcash/librustzcash"
repository = "https://github.com/zcash/librustzcash"

18
zcash_client_sqlite/src/lib.rs
View File

@ -563,8 +563,10 @@ mod tests {
block::BlockHash,
consensus::{BlockHeight, Network, NetworkUpgrade, Parameters},
memo::MemoBytes,
note_encryption::SaplingNoteEncryption,
sapling::{util::generate_random_rseed, Note, Nullifier, PaymentAddress},
sapling::{
note_encryption::sapling_note_encryption, util::generate_random_rseed, Note, Nullifier,
PaymentAddress,
},
transaction::components::Amount,
zip32::ExtendedFullViewingKey,
};
@ -614,7 +616,7 @@ mod tests {
value: value.into(),
rseed,
};
let encryptor = SaplingNoteEncryption::new(
let encryptor = sapling_note_encryption::<_, Network>(
Some(extfvk.fvk.ovk),
note.clone(),
to,
@ -629,7 +631,7 @@ mod tests {
let mut cout = CompactOutput::new();
cout.set_cmu(cmu);
cout.set_epk(epk);
cout.set_ciphertext(enc_ciphertext[..52].to_vec());
cout.set_ciphertext(enc_ciphertext.as_ref()[..52].to_vec());
let mut ctx = CompactTx::new();
let mut txid = vec![0; 32];
rng.fill_bytes(&mut txid);
@ -674,7 +676,7 @@ mod tests {
value: value.into(),
rseed,
};
let encryptor = SaplingNoteEncryption::new(
let encryptor = sapling_note_encryption::<_, Network>(
Some(extfvk.fvk.ovk),
note.clone(),
to,
@ -688,7 +690,7 @@ mod tests {
let mut cout = CompactOutput::new();
cout.set_cmu(cmu);
cout.set_epk(epk);
cout.set_ciphertext(enc_ciphertext[..52].to_vec());
cout.set_ciphertext(enc_ciphertext.as_ref()[..52].to_vec());
cout
});
@ -702,7 +704,7 @@ mod tests {
value: (in_value - value).into(),
rseed,
};
let encryptor = SaplingNoteEncryption::new(
let encryptor = sapling_note_encryption::<_, Network>(
Some(extfvk.fvk.ovk),
note.clone(),
change_addr,
@ -716,7 +718,7 @@ mod tests {
let mut cout = CompactOutput::new();
cout.set_cmu(cmu);
cout.set_epk(epk);
cout.set_ciphertext(enc_ciphertext[..52].to_vec());
cout.set_ciphertext(enc_ciphertext.as_ref()[..52].to_vec());
cout
});

9
zcash_client_sqlite/src/wallet/transact.rs
View File

@ -155,8 +155,7 @@ mod tests {
block::BlockHash,
consensus::BlockHeight,
legacy::TransparentAddress,
note_encryption::try_sapling_output_recovery,
sapling::prover::TxProver,
sapling::{note_encryption::try_sapling_output_recovery, prover::TxProver},
transaction::{components::Amount, Transaction},
zip32::{ExtendedFullViewingKey, ExtendedSpendingKey},
};
@ -635,11 +634,7 @@ mod tests {
&network,
sapling_activation_height(),
&extfvk.fvk.ovk,
&output.cv,
&output.cmu,
&output.ephemeral_key,
&output.enc_ciphertext,
&output.out_ciphertext,
output,
)
};

2
zcash_primitives/Cargo.toml
View File

@ -4,6 +4,7 @@ description = "Rust implementations of the Zcash primitives"
version = "0.5.0"
authors = [
"Jack Grigg <jack@z.cash>",
"Kris Nuttycombe <kris@electriccoin.co>"
]
homepage = "https://github.com/zcash/librustzcash"
repository = "https://github.com/zcash/librustzcash"
@ -37,6 +38,7 @@ ripemd160 = { version = "0.9", optional = true }
secp256k1 = { version = "0.20", optional = true }
sha2 = "0.9"
subtle = "2.2.3"
zcash_note_encryption = { version = "0.0", path = "../components/zcash_note_encryption" }
# Temporary workaround for https://github.com/myrrlyn/funty/issues/3
funty = "=1.1.0"

37
zcash_primitives/benches/note_decryption.rs
View File

@ -2,11 +2,12 @@ use criterion::{criterion_group, criterion_main, Criterion};
use ff::Field;
use rand_core::OsRng;
use zcash_primitives::{
consensus::{NetworkUpgrade::Canopy, Parameters, TEST_NETWORK},
consensus::{NetworkUpgrade::Canopy, Parameters, TestNetwork, TEST_NETWORK},
memo::MemoBytes,
note_encryption::{try_sapling_note_decryption, SaplingNoteEncryption},
sapling::{
util::generate_random_rseed, Diversifier, PaymentAddress, SaplingIvk, ValueCommitment,
note_encryption::{sapling_note_encryption, try_sapling_note_decryption},
util::generate_random_rseed,
Diversifier, PaymentAddress, SaplingIvk, ValueCommitment,
},
transaction::components::{OutputDescription, GROTH_PROOF_SIZE},
};
@ -37,10 +38,11 @@ fn bench_note_decryption(c: &mut Criterion) {
let note = pa.create_note(value, rseed).unwrap();
let cmu = note.cmu();
let mut ne = SaplingNoteEncryption::new(None, note, pa, MemoBytes::empty(), &mut rng);
let ephemeral_key = ne.epk().clone().into();
let ne =
sapling_note_encryption::<_, TestNetwork>(None, note, pa, MemoBytes::empty(), &mut rng);
let ephemeral_key = *ne.epk();
let enc_ciphertext = ne.encrypt_note_plaintext();
let out_ciphertext = ne.encrypt_outgoing_plaintext(&cv, &cmu);
let out_ciphertext = ne.encrypt_outgoing_plaintext(&cv, &cmu, &mut rng);
OutputDescription {
cv,
@ -55,30 +57,11 @@ fn bench_note_decryption(c: &mut Criterion) {
let mut group = c.benchmark_group("Sapling note decryption");
group.bench_function("valid", |b| {
b.iter(|| {
try_sapling_note_decryption(
&TEST_NETWORK,
height,
&valid_ivk,
&output.ephemeral_key,
&output.cmu,
&output.enc_ciphertext,
)
.unwrap()
})
b.iter(|| try_sapling_note_decryption(&TEST_NETWORK, height, &valid_ivk, &output).unwrap())
});
group.bench_function("invalid", |b| {
b.iter(|| {
try_sapling_note_decryption(
&TEST_NETWORK,
height,
&invalid_ivk,
&output.ephemeral_key,
&output.cmu,
&output.enc_ciphertext,
)
})
b.iter(|| try_sapling_note_decryption(&TEST_NETWORK, height, &invalid_ivk, &output))
});
}

1
zcash_primitives/src/lib.rs
View File

@ -15,7 +15,6 @@ pub mod constants;
pub mod legacy;
pub mod memo;
pub mod merkle_tree;
pub mod note_encryption;
pub mod sapling;
pub mod serialize;
pub mod transaction;

1734
zcash_primitives/src/note_encryption.rs
View File

File diff suppressed because it is too large Load Diff

5
zcash_primitives/src/sapling.rs
View File

@ -2,6 +2,7 @@
pub mod group_hash;
pub mod keys;
pub mod note_encryption;
pub mod pedersen_hash;
pub mod prover;
pub mod redjubjub;
@ -325,10 +326,10 @@ impl PaymentAddress {
self.diversifier.g_d()
}
pub fn create_note(&self, value: u64, randomness: Rseed) -> Option<Note> {
pub fn create_note(&self, value: u64, rseed: Rseed) -> Option<Note> {
self.g_d().map(|g_d| Note {
value,
rseed: randomness,
rseed,
g_d,
pk_d: self.pk_d,
})

1353
zcash_primitives/src/sapling/note_encryption.rs Normal file
View File

File diff suppressed because it is too large Load Diff

37
zcash_primitives/src/transaction/builder.rs
View File

@ -15,10 +15,10 @@ use crate::{
legacy::TransparentAddress,
memo::MemoBytes,
merkle_tree::MerklePath,
note_encryption::SaplingNoteEncryption,
sapling::{
keys::OutgoingViewingKey, prover::TxProver, redjubjub::PrivateKey, spend_sig_internal,
util::generate_random_rseed_internal, Diversifier, Node, Note, PaymentAddress,
keys::OutgoingViewingKey, note_encryption::sapling_note_encryption, prover::TxProver,
redjubjub::PrivateKey, spend_sig_internal, util::generate_random_rseed_internal,
Diversifier, Node, Note, PaymentAddress,
},
transaction::{
components::{
@ -93,16 +93,17 @@ struct SpendDescriptionInfo {
merkle_path: MerklePath<Node>,
}
pub struct SaplingOutput {
pub struct SaplingOutput<P: consensus::Parameters> {
/// `None` represents the `ovk = ⊥` case.
ovk: Option<OutgoingViewingKey>,
to: PaymentAddress,
note: Note,
memo: MemoBytes,
_params: PhantomData<P>,
}
impl SaplingOutput {
pub fn new<R: RngCore + CryptoRng, P: consensus::Parameters>(
impl<P: consensus::Parameters> SaplingOutput<P> {
pub fn new<R: RngCore + CryptoRng>(
params: &P,
height: BlockHeight,
rng: &mut R,
@ -114,7 +115,7 @@ impl SaplingOutput {
Self::new_internal(params, height, rng, ovk, to, value, memo)
}
fn new_internal<R: RngCore, P: consensus::Parameters>(
fn new_internal<R: RngCore>(
params: &P,
height: BlockHeight,
rng: &mut R,
@ -142,25 +143,26 @@ impl SaplingOutput {
to,
note,
memo: memo.unwrap_or_else(MemoBytes::empty),
_params: PhantomData::default(),
})
}
pub fn build<P: TxProver, R: RngCore + CryptoRng>(
pub fn build<Pr: TxProver, R: RngCore + CryptoRng>(
self,
prover: &P,
ctx: &mut P::SaplingProvingContext,
prover: &Pr,
ctx: &mut Pr::SaplingProvingContext,
rng: &mut R,
) -> OutputDescription {
self.build_internal(prover, ctx, rng)
}
fn build_internal<P: TxProver, R: RngCore>(
fn build_internal<Pr: TxProver, R: RngCore>(
self,
prover: &P,
ctx: &mut P::SaplingProvingContext,
prover: &Pr,
ctx: &mut Pr::SaplingProvingContext,
rng: &mut R,
) -> OutputDescription {
let mut encryptor = SaplingNoteEncryption::new_internal(
let encryptor = sapling_note_encryption::<R, P>(
self.ovk,
self.note.clone(),
self.to.clone(),
@ -179,9 +181,8 @@ impl SaplingOutput {
let cmu = self.note.cmu();
let enc_ciphertext = encryptor.encrypt_note_plaintext();
let out_ciphertext = encryptor.encrypt_outgoing_plaintext(&cv, &cmu);
let ephemeral_key = encryptor.epk().clone().into();
let out_ciphertext = encryptor.encrypt_outgoing_plaintext(&cv, &cmu, rng);
let ephemeral_key = *encryptor.epk();
OutputDescription {
cv,
@ -371,7 +372,7 @@ pub struct Builder<'a, P: consensus::Parameters, R: RngCore> {
fee: Amount,
anchor: Option<bls12_381::Scalar>,
spends: Vec<SpendDescriptionInfo>,
outputs: Vec<SaplingOutput>,
outputs: Vec<SaplingOutput<P>>,
transparent_inputs: TransparentInputs,
#[cfg(feature = "zfuture")]
tze_inputs: TzeInputs<'a, TransactionData>,

58
zcash_primitives/src/transaction/components/sapling.rs
View File

@ -3,11 +3,19 @@ use group::GroupEncoding;
use std::io::{self, Read, Write};
use crate::sapling::{
redjubjub::{PublicKey, Signature},
Nullifier,
use zcash_note_encryption::ShieldedOutput;
use crate::{
consensus,
sapling::{
note_encryption::SaplingDomain,
redjubjub::{PublicKey, Signature},
Nullifier,
},
};
use zcash_note_encryption::COMPACT_NOTE_SIZE;
use super::GROTH_PROOF_SIZE;
#[derive(Clone)]
@ -110,6 +118,20 @@ pub struct OutputDescription {
pub zkproof: [u8; GROTH_PROOF_SIZE],
}
impl<P: consensus::Parameters> ShieldedOutput<SaplingDomain<P>> for OutputDescription {
fn epk(&self) -> &jubjub::ExtendedPoint {
&self.ephemeral_key
}
fn cmstar_bytes(&self) -> [u8; 32] {
self.cmu.to_repr()
}
fn enc_ciphertext(&self) -> &[u8] {
&self.enc_ciphertext
}
}
impl std::fmt::Debug for OutputDescription {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> Result<(), std::fmt::Error> {
write!(
@ -191,3 +213,33 @@ impl OutputDescription {
writer.write_all(&self.zkproof)
}
}
pub struct CompactOutputDescription {
pub epk: jubjub::ExtendedPoint,
pub cmu: bls12_381::Scalar,
pub enc_ciphertext: Vec<u8>,
}
impl From<OutputDescription> for CompactOutputDescription {
fn from(out: OutputDescription) -> CompactOutputDescription {
CompactOutputDescription {
epk: out.ephemeral_key,
cmu: out.cmu,
enc_ciphertext: out.enc_ciphertext[..COMPACT_NOTE_SIZE].to_vec(),
}
}
}
impl<P: consensus::Parameters> ShieldedOutput<SaplingDomain<P>> for CompactOutputDescription {
fn epk(&self) -> &jubjub::ExtendedPoint {
&self.epk
}
fn cmstar_bytes(&self) -> [u8; 32] {
self.cmu.to_repr()
}
fn enc_ciphertext(&self) -> &[u8] {
&self.enc_ciphertext
}
}