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zcash_note_encryption
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Use ephemeral_key bytes instead of the epk abstract point where specified. 

Extracted from: 6fc1d1d1c0
This commit is contained in:
Kris Nuttycombe 2021-04-12 16:19:50 -06:00
parent 3843f4ba2b
commit 2884d70e29
1 changed files with 17 additions and 9 deletions
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26
src/lib.rs
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@ -35,6 +35,12 @@ impl AsRef<[u8]> for OutgoingCipherKey {
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)
@ -90,7 +96,7 @@ pub trait Domain {
epk: &Self::EphemeralPublicKey,
) -> Self::SharedSecret;
fn kdf(secret: Self::SharedSecret, epk: &Self::EphemeralPublicKey) -> Self::SymmetricKey;
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
@ -101,11 +107,11 @@ pub trait Domain {
memo: &Self::Memo,
) -> NotePlaintextBytes;
fn get_ock(
fn derive_ock(
ovk: &Self::OutgoingViewingKey,
cv: &Self::ValueCommitment,
cm: &Self::NoteCommitment,
epk: &Self::EphemeralPublicKey,
ephemeral_key: &EphemeralKeyBytes,
) -> OutgoingCipherKey;
fn outgoing_plaintext_bytes(
@ -227,7 +233,9 @@ impl<D: Domain> NoteEncryption<D> {
Self::new_with_esk(esk, ovk, note, to, memo)
}
/// For use only with Sapling.
/// 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>,
@ -259,7 +267,7 @@ impl<D: Domain> NoteEncryption<D> {
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, &self.epk);
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];
@ -281,7 +289,7 @@ impl<D: Domain> NoteEncryption<D> {
rng: &mut R,
) -> [u8; OUT_CIPHERTEXT_SIZE] {
let (ock, input) = if let Some(ovk) = &self.ovk {
let ock = D::get_ock(ovk, &cv, &cm, &self.epk);
let ock = D::derive_ock(ovk, &cv, &cm, &D::epk_bytes(&self.epk));
let input = D::outgoing_plaintext_bytes(&self.note, &self.esk);
(ock, input)
@ -323,7 +331,7 @@ pub fn try_note_decryption<D: Domain, Output: ShieldedOutput<D>>(
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, output.epk());
let key = D::kdf(shared_secret, &D::epk_bytes(output.epk()));
let mut plaintext = [0; ENC_CIPHERTEXT_SIZE];
assert_eq!(
@ -407,7 +415,7 @@ pub fn try_compact_note_decryption<D: Domain, Output: ShieldedOutput<D>>(
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, 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];
@ -446,7 +454,7 @@ pub fn try_output_recovery_with_ock<D: Domain, Output: ShieldedOutput<D>>(
let esk = D::extract_esk(&op)?;
let shared_secret = D::ka_agree_enc(&esk, &pk_d);
let key = D::kdf(shared_secret, output.epk());
let key = D::kdf(shared_secret, &D::epk_bytes(output.epk()));
let mut plaintext = [0; ENC_CIPHERTEXT_SIZE];
assert_eq!(