snarkvm_console_program/data/record/
encrypt.rs

1// Copyright 2024 Aleo Network Foundation
2// This file is part of the snarkVM library.
3
4// Licensed under the Apache License, Version 2.0 (the "License");
5// you may not use this file except in compliance with the License.
6// You may obtain a copy of the License at:
7
8// http://www.apache.org/licenses/LICENSE-2.0
9
10// Unless required by applicable law or agreed to in writing, software
11// distributed under the License is distributed on an "AS IS" BASIS,
12// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13// See the License for the specific language governing permissions and
14// limitations under the License.
15
16use super::*;
17
18impl<N: Network> Record<N, Plaintext<N>> {
19    /// Encrypts `self` for the record owner under the given randomizer.
20    pub fn encrypt(&self, randomizer: Scalar<N>) -> Result<Record<N, Ciphertext<N>>> {
21        // Ensure the randomizer corresponds to the record nonce.
22        if self.nonce == N::g_scalar_multiply(&randomizer) {
23            // Compute the record view key.
24            let record_view_key = (**self.owner * randomizer).to_x_coordinate();
25            // Encrypt the record.
26            self.encrypt_symmetric_unchecked(&record_view_key)
27        } else {
28            bail!("Illegal operation: Record::encrypt() randomizer does not correspond to the record nonce.")
29        }
30    }
31
32    /// Encrypts `self` under the given record view key.
33    /// Note: This method does not check that the record view key corresponds to the record owner.
34    /// Use `Self::encrypt` for the checked variant.
35    pub fn encrypt_symmetric_unchecked(&self, record_view_key: &Field<N>) -> Result<Record<N, Ciphertext<N>>> {
36        // Determine the number of randomizers needed to encrypt the record.
37        let num_randomizers = self.num_randomizers()?;
38        // Prepare a randomizer for each field element.
39        let randomizers = N::hash_many_psd8(&[N::encryption_domain(), *record_view_key], num_randomizers);
40        // Encrypt the record.
41        self.encrypt_with_randomizers(&randomizers)
42    }
43
44    /// Encrypts `self` under the given randomizers.
45    fn encrypt_with_randomizers(&self, randomizers: &[Field<N>]) -> Result<Record<N, Ciphertext<N>>> {
46        // Initialize an index to keep track of the randomizer index.
47        let mut index: usize = 0;
48
49        // Encrypt the owner.
50        let owner = match self.owner.is_public() {
51            true => self.owner.encrypt_with_randomizer(&[])?,
52            false => self.owner.encrypt_with_randomizer(&[randomizers[index]])?,
53        };
54
55        // Increment the index if the owner is private.
56        if owner.is_private() {
57            index += 1;
58        }
59
60        // Encrypt the data.
61        let mut encrypted_data = IndexMap::with_capacity(self.data.len());
62        for (id, entry, num_randomizers) in self.data.iter().map(|(id, entry)| (id, entry, entry.num_randomizers())) {
63            // Retrieve the result for `num_randomizers`.
64            let num_randomizers = num_randomizers? as usize;
65            // Retrieve the randomizers for this entry.
66            let randomizers = &randomizers[index..index + num_randomizers];
67            // Encrypt the entry.
68            let entry = match entry {
69                // Constant entries do not need to be encrypted.
70                Entry::Constant(plaintext) => Entry::Constant(plaintext.clone()),
71                // Public entries do not need to be encrypted.
72                Entry::Public(plaintext) => Entry::Public(plaintext.clone()),
73                // Private entries are encrypted with the given randomizers.
74                Entry::Private(private) => Entry::Private(Ciphertext::try_from(
75                    private
76                        .to_fields()?
77                        .iter()
78                        .zip_eq(randomizers)
79                        .map(|(plaintext, randomizer)| *plaintext + randomizer)
80                        .collect::<Vec<_>>(),
81                )?),
82            };
83            // Insert the encrypted entry.
84            if encrypted_data.insert(*id, entry).is_some() {
85                bail!("Duplicate identifier in record: {}", id);
86            }
87            // Increment the index.
88            index += num_randomizers;
89        }
90
91        // Return the encrypted record.
92        Self::from_ciphertext(owner, encrypted_data, self.nonce)
93    }
94}
snarkvm_console_program/data/record/encrypt.rs

snarkvm_console_program/data/record/
encrypt.rs
