1  // Copyright (c) 2019-2025 Alpha-Delta Network Inc.
 2  // This file is part of the alphavm 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  
16  use super::*;
17  
18  impl<N: Network> FromBytes for Ciphertext<N> {
19      /// Reads the ciphertext from a buffer.
20      #[inline]
21      fn read_le<R: Read>(mut reader: R) -> IoResult<Self> {
22          // Read the number of field elements.
23          let num_fields = u16::read_le(&mut reader)?;
24          // Ensure the number of field elements does not exceed the maximum allowed size.
25          match num_fields as u32 <= N::MAX_DATA_SIZE_IN_FIELDS {
26              // Read the field elements.
27              true => {
28                  Ok(Ciphertext((0..num_fields).map(|_| Field::read_le(&mut reader)).collect::<Result<Vec<_>, _>>()?))
29              }
30              false => Err(error("Ciphertext is too large to encode in field elements.")),
31          }
32      }
33  }
34  
35  impl<N: Network> ToBytes for Ciphertext<N> {
36      /// Writes the ciphertext to a buffer.
37      #[inline]
38      fn write_le<W: Write>(&self, mut writer: W) -> IoResult<()> {
39          // Ensure the number of field elements does not exceed the maximum allowed size.
40          if u32::try_from(self.0.len()).or_halt::<N>() > N::MAX_DATA_SIZE_IN_FIELDS || self.0.len() > u16::MAX as usize {
41              return Err(error("Ciphertext is too large to encode in field elements."));
42          }
43          // Write the number of ciphertext field elements.
44          u16::try_from(self.0.len()).or_halt::<N>().write_le(&mut writer)?;
45          // Write the ciphertext field elements.
46          self.0.write_le(&mut writer)
47      }
48  }
49  
50  #[cfg(test)]
51  mod tests {
52      use super::*;
53      use alphavm_console_network::MainnetV0;
54  
55      type CurrentNetwork = MainnetV0;
56  
57      const ITERATIONS: u32 = 1000;
58  
59      #[test]
60      fn test_bytes() -> Result<()> {
61          let mut rng = TestRng::default();
62  
63          for _ in 0..ITERATIONS {
64              // Sample a new ciphertext.
65              let expected = Ciphertext::<CurrentNetwork>((0..100).map(|_| Uniform::rand(&mut rng)).collect::<Vec<_>>());
66  
67              // Check the byte representation.
68              let expected_bytes = expected.to_bytes_le()?;
69              assert_eq!(expected, Ciphertext::read_le(&expected_bytes[..])?);
70          }
71          Ok(())
72      }
73  }