opaque-borink 0.4.1

pub mod client;
pub mod server;

use base64::DecodeError;
use base64::{engine::general_purpose as b64, Engine as _};
use opaque_ke::ciphersuite::CipherSuite;
pub use opaque_ke::errors::ProtocolError;
use opaque_ke::ServerSetup;
use rand::rngs::OsRng;
use std::fmt::{Debug, Display, Formatter};

mod argon_backport {
    use opaque_ke::{errors::InternalError, ksf::Ksf};
    use generic_array::{ArrayLength, GenericArray};

    #[derive(Default)]
    pub struct Argon0d4d1Wrapper(argon2::Argon2<'static>);

    // Below code is taken directly from the `opaque-ke` project licensed under Apache 2.0/MIT
    // Necessary because new version uses Argon 0.5 which changed its parameters
    impl Ksf for Argon0d4d1Wrapper {
        fn hash<L: ArrayLength<u8>>(
            &self,
            input: GenericArray<u8, L>,
        ) -> Result<GenericArray<u8, L>, InternalError> {
            let mut output = GenericArray::default();
            self.0.hash_password_into(&input, &[0; argon2::RECOMMENDED_SALT_LEN], &mut output)
                .map_err(|_| InternalError::KsfError)?;
            Ok(output)
        }
    }
}

pub struct Cipher;
impl CipherSuite for Cipher {
    type OprfCs = opaque_ke::Ristretto255;
    type KeGroup = opaque_ke::Ristretto255;
    type KeyExchange = opaque_ke::key_exchange::tripledh::TripleDh;
    type Ksf = argon_backport::Argon0d4d1Wrapper;
}

#[derive(Debug)]
pub enum Error {
    ProtocolError(ProtocolError),
    DecodeError(DecodeError),
}

impl Display for Error {
    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
        write!(f, "{:?}", &self)
    }
}

impl std::error::Error for Error {}

impl From<ProtocolError> for Error {
    fn from(e: ProtocolError) -> Self {
        Error::ProtocolError(e)
    }
}

impl From<DecodeError> for Error {
    fn from(e: DecodeError) -> Self {
        Error::DecodeError(e)
    }
}

pub fn create_setup() -> String {
    let mut rng = OsRng;
    let server_setup = ServerSetup::<Cipher>::new(&mut rng);
    let server_setup_serialized = ServerSetup::serialize(&server_setup);

    b64::URL_SAFE_NO_PAD.encode(server_setup_serialized)
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn gen_test() {
        let serv_setp = create_setup();
        println!("{}", serv_setp);
    }
}