snarkos-cli 4.6.2

// Copyright (c) 2019-2026 Provable Inc.
// This file is part of the snarkOS 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 snarkvm::{
    console::{network::Network, program::Ciphertext},
    prelude::{Record, ViewKey},
};

use anyhow::{Context, Result, bail};
use clap::{Parser, builder::NonEmptyStringValueParser};
use std::str::FromStr;
use zeroize::Zeroize;

/// Decrypts a record ciphertext.
#[derive(Debug, Parser, Zeroize)]
pub struct Decrypt {
    /// The record ciphertext to decrypt.
    #[clap(short, long)]
    ciphertext: String,
    /// The view key used to decrypt the record ciphertext.
    #[clap(short, long, value_parser=NonEmptyStringValueParser::default())]
    view_key: String,
    /// Sets verbosity of log output. By default, no logs are shown.
    #[clap(long)]
    verbosity: Option<u8>,
}

impl Decrypt {
    /// Decrypt the record specified by the user.
    pub fn parse<N: Network>(self) -> Result<String> {
        // Parse the ciphertext record.
        let ciphertext_record = Record::<N, Ciphertext<N>>::from_str(&self.ciphertext)
            .with_context(|| "Failed to parse ciphertext record")?;

        // Parse the account view key.
        let view_key = ViewKey::<N>::from_str(&self.view_key).with_context(|| "Failed to parse view key")?;

        match ciphertext_record.decrypt(&view_key) {
            Ok(plaintext_record) => Ok(plaintext_record.to_string()),
            Err(_) => bail!("Invalid view key for the provided record ciphertext"),
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use snarkvm::prelude::{
        Address,
        Entry,
        Field,
        Identifier,
        Literal,
        MainnetV0,
        Network,
        One,
        Owner,
        Plaintext,
        PrivateKey,
        Scalar,
        TestRng,
        U8,
        Uniform,
        ViewKey,
        Zero,
    };

    use indexmap::IndexMap;
    use rand::Rng;

    type CurrentNetwork = MainnetV0;

    const ITERATIONS: usize = 1000;

    fn construct_ciphertext<N: Network>(
        view_key: ViewKey<N>,
        owner: Owner<N, Plaintext<N>>,
        rng: &mut TestRng,
    ) -> Result<Record<N, Ciphertext<N>>> {
        // Prepare the record.
        let randomizer = Scalar::rand(rng);
        let version = match rng.r#gen() {
            true => U8::<N>::one(),
            false => U8::<N>::zero(),
        };
        let record = Record::<N, Plaintext<N>>::from_plaintext(
            owner,
            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))))),
                ]
                .into_iter(),
            ),
            N::g_scalar_multiply(&randomizer),
            version,
        )?;
        // Encrypt the record.
        let ciphertext = record.encrypt(randomizer)?;
        // Decrypt the record.
        assert_eq!(record, ciphertext.decrypt(&view_key)?);

        Ok(ciphertext)
    }

    #[test]
    fn test_decryption() {
        let mut rng = TestRng::default();

        for _ in 0..ITERATIONS {
            let private_key = PrivateKey::<CurrentNetwork>::new(&mut rng).unwrap();
            let view_key = ViewKey::try_from(private_key).unwrap();
            let address = Address::try_from(private_key).unwrap();

            // Construct the ciphertext.
            let owner = Owner::Private(Plaintext::from(Literal::Address(address)));
            let ciphertext = construct_ciphertext(view_key, owner, &mut rng).unwrap();

            // Decrypt the ciphertext.
            let expected_plaintext = ciphertext.decrypt(&view_key).unwrap();

            let decrypt =
                Decrypt { ciphertext: ciphertext.to_string(), view_key: view_key.to_string(), verbosity: None };
            let plaintext = decrypt.parse::<CurrentNetwork>().unwrap();

            // Check that the decryption is correct.
            assert_eq!(plaintext, expected_plaintext.to_string());
        }
    }

    #[test]
    fn test_failed_decryption() {
        let mut rng = TestRng::default();

        // Generate a view key that is unaffiliated with the ciphertext.
        let incorrect_private_key = PrivateKey::<CurrentNetwork>::new(&mut rng).unwrap();
        let incorrect_view_key = ViewKey::try_from(incorrect_private_key).unwrap();

        for _ in 0..ITERATIONS {
            let private_key = PrivateKey::<CurrentNetwork>::new(&mut rng).unwrap();
            let view_key = ViewKey::try_from(private_key).unwrap();
            let address = Address::try_from(private_key).unwrap();

            // Construct the ciphertext.
            let owner = Owner::Private(Plaintext::from(Literal::Address(address)));
            let ciphertext = construct_ciphertext::<CurrentNetwork>(view_key, owner, &mut rng).unwrap();

            // Enforce that the decryption fails.
            let decrypt = Decrypt {
                ciphertext: ciphertext.to_string(),
                view_key: incorrect_view_key.to_string(),
                verbosity: None,
            };
            assert!(decrypt.parse::<CurrentNetwork>().is_err());
        }
    }
}