1  // Copyright (c) 2019-2025 Alpha-Delta Network Inc.
 2  // This file is part of the deltavm 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<E: Environment, const NUM_BITS: u8> HashUncompressed for Pedersen<E, NUM_BITS> {
19      type Input = bool;
20      type Output = Group<E>;
21  
22      /// Returns the Pedersen hash of the given input as a group element.
23      fn hash_uncompressed(&self, input: &[Self::Input]) -> Result<Self::Output> {
24          let mut input = Cow::Borrowed(input);
25          match input.len() <= NUM_BITS as usize {
26              // Pad the input if it is under the required parameter size.
27              true => input.to_mut().resize(NUM_BITS as usize, false),
28              // Ensure the input size is within the parameter size,
29              false => bail!("Invalid input size for Pedersen: expected <= {NUM_BITS}, found {}", input.len()),
30          }
31  
32          // Compute sum of h_i^{m_i} for all i.
33          Ok(input
34              .iter()
35              .zip_eq(&*self.base_window)
36              .flat_map(|(bit, base)| match bit {
37                  true => Some(*base),
38                  false => None,
39              })
40              .sum())
41      }
42  }