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// Copyright (c) 2019-2026 Provable Inc.
// This file is part of the snarkVM library.
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at:
// http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
use super::*;
impl<N: Network> Record<N, Ciphertext<N>> {
/// Decrypts `self` into plaintext using the given view key and checks that the owner matches the view key.
pub fn decrypt(&self, view_key: &ViewKey<N>) -> Result<Record<N, Plaintext<N>>> {
// Compute the record view key.
let record_view_key = (self.nonce * **view_key).to_x_coordinate();
// Decrypt the record.
let record = self.decrypt_symmetric_unchecked(&record_view_key)?;
// Ensure the record owner matches the view key.
match view_key.to_address() == **record.owner() {
true => Ok(record),
false => bail!("Illegal operation: Record::decrypt() view key does not correspond to the record owner."),
}
}
/// Decrypts `self` into plaintext using the given record view key.
/// Note: This method does not check that the record view key corresponds to the record owner.
/// Use `Self::decrypt` for the checked variant.
pub fn decrypt_symmetric_unchecked(&self, record_view_key: &Field<N>) -> Result<Record<N, Plaintext<N>>> {
// Determine the number of randomizers needed to encrypt the record.
let num_randomizers = self.num_randomizers()?;
// Prepare a randomizer for each field element.
let randomizers = N::hash_many_psd8(&[N::encryption_domain(), *record_view_key], num_randomizers);
// Decrypt the record.
self.decrypt_with_randomizers(&randomizers)
}
/// Decrypts `self` into plaintext using the given randomizers.
fn decrypt_with_randomizers(&self, randomizers: &[Field<N>]) -> Result<Record<N, Plaintext<N>>> {
// Initialize an index to keep track of the randomizer index.
let mut index: usize = 0;
// Decrypt the owner.
let owner = match self.owner.is_public() {
true => self.owner.decrypt_with_randomizer(&[])?,
false => self.owner.decrypt_with_randomizer(&[randomizers[index]])?,
};
// Increment the index if the owner is private.
if owner.is_private() {
index += 1;
}
// Decrypt the program data.
let mut decrypted_data = IndexMap::with_capacity(self.data.len());
for (id, entry, num_randomizers) in self.data.iter().map(|(id, entry)| (id, entry, entry.num_randomizers())) {
// Retrieve the result for `num_randomizers`.
let num_randomizers = num_randomizers? as usize;
// Retrieve the randomizers for this entry.
let randomizers = &randomizers[index..index + num_randomizers];
// Decrypt the entry.
let entry = match entry {
// Constant entries do not need to be decrypted.
Entry::Constant(plaintext) => Entry::Constant(plaintext.clone()),
// Public entries do not need to be decrypted.
Entry::Public(plaintext) => Entry::Public(plaintext.clone()),
// Private entries are decrypted with the given randomizers.
Entry::Private(private) => Entry::Private(Plaintext::from_fields(
&private
.iter()
.zip_eq(randomizers)
.map(|(ciphertext, randomizer)| *ciphertext - randomizer)
.collect::<Vec<_>>(),
)?),
};
// Insert the decrypted entry.
if decrypted_data.insert(*id, entry).is_some() {
bail!("Duplicate identifier in record: {id}");
}
// Increment the index.
index += num_randomizers;
}
// Return the decrypted record.
Self::from_plaintext(owner, decrypted_data, self.nonce, self.version)
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::Literal;
use snarkvm_console_account::PrivateKey;
use snarkvm_console_network::MainnetV0;
use snarkvm_console_types::Field;
type CurrentNetwork = MainnetV0;
const ITERATIONS: u64 = 1000;
fn check_encrypt_and_decrypt<N: Network>(
view_key: ViewKey<N>,
owner: Owner<N, Plaintext<N>>,
rng: &mut TestRng,
) -> Result<()> {
// Prepare the record.
let randomizer = Scalar::rand(rng);
let record = Record {
owner,
data: IndexMap::from_iter(vec![
(Identifier::from_str("a")?, Entry::Private(Plaintext::from(Literal::Field(Field::rand(rng))))),
(Identifier::from_str("b")?, Entry::Private(Plaintext::from(Literal::Scalar(Scalar::rand(rng))))),
]),
nonce: N::g_scalar_multiply(&randomizer),
version: U8::rand(rng),
};
// Encrypt the record.
let ciphertext = record.encrypt(randomizer)?;
// Decrypt the record.
assert_eq!(record, ciphertext.decrypt(&view_key)?);
// Generate a new random private key.
let incorrect_private_key = PrivateKey::<N>::new(rng)?;
// Generate a new view key.
let incorrect_view_key = ViewKey::try_from(&incorrect_private_key)?;
// Ensure that decrypting with the incorrect view key fails.
assert!(ciphertext.decrypt(&incorrect_view_key).is_err());
Ok(())
}
#[test]
fn test_encrypt_and_decrypt() -> Result<()> {
let mut rng = TestRng::default();
for _ in 0..ITERATIONS {
// Sample a view key and address.
let private_key = PrivateKey::<CurrentNetwork>::new(&mut rng)?;
let view_key = ViewKey::try_from(&private_key)?;
let address = Address::try_from(&private_key)?;
// Public owner.
let owner = Owner::Public(address);
check_encrypt_and_decrypt::<CurrentNetwork>(view_key, owner, &mut rng)?;
// Private owner.
let owner = Owner::Private(Plaintext::from(Literal::Address(address)));
check_encrypt_and_decrypt::<CurrentNetwork>(view_key, owner, &mut rng)?;
}
Ok(())
}
}