microsalt 0.2.21

//////////////////////////////////////
//Public Key Authenticated Encryption
//////////////////////////////////////
//https://github.com/erik/knuckle/blob/master/src/cryptobox.rs
//https://github.com/maidsafe/rust_sodium/blob/master/src/crypto/box_/curve25519xsalsa20poly1305.rs
//! `crypto_box` uses "public-key authenticators" rather than "public-key signatures."

mod curve25519xsalsa20poly1305;
use shared;

//Key Generation
///A Pubic key for crypto box
pub struct PublicKey ([u8; curve25519xsalsa20poly1305::PUBLIC_KEY_LEN]);
///A secret key for crypto box
pub struct SecretKey ([u8; curve25519xsalsa20poly1305::SECRET_KEY_LEN]);

/// A asymmetric keypair containing matching public and private keys.
pub struct Keypair {
    /// Public key
    pub public: PublicKey,
    /// Private key
    pub secret: SecretKey
}


impl Keypair {
    /// Generate a random matching public and private key.
    pub fn new() -> Keypair {
        let mut pk = [0u8; curve25519xsalsa20poly1305::PUBLIC_KEY_LEN];
        let mut sk = [0u8; curve25519xsalsa20poly1305::SECRET_KEY_LEN];
        
        curve25519xsalsa20poly1305::box_keypair(&mut pk, &mut sk);
        //Return New Key Pair
        Keypair { public: PublicKey(pk), secret: SecretKey(sk) }
    }

}

//For Secret key we must implement the drop trait to zero out the used memory
impl Drop for SecretKey {
    fn drop(&mut self) {
        println!("Dropping Secret KEY, but must ZERO OUT MEMORY!!!!!");
        //use utils::memzero;
        //let &mut $name(ref mut v) = self;
        //memzero(v);
    }
}

//A Box encapsulates the cipher text and associated nonce value, it is ok to be public 
pub struct Box{
    pub nonce: [u8; curve25519xsalsa20poly1305::NONCE_LEN],
    pub cipher: Vec<u8>
}

/// Struct enabling bidirectional asymmetrically encrypted communication between two parties.ß
pub struct CryptoBox {
    /// Key used to decrypt messages passed to this CryptoBox. Sender must have
    /// the matching public key.
    pub secret_key: SecretKey,
    /// Key used to encrypt messages to some other party.
    pub public_key: PublicKey
}

//Internal lock function that can be used for tests aswell
fn internal_lock(message: &[u8], nonce: [u8; curve25519xsalsa20poly1305::NONCE_LEN], pk: &PublicKey, sk: &SecretKey) -> Box {
        let mut cipher = Vec::with_capacity(message.len() + curve25519xsalsa20poly1305::ZERO_LEN);
        cipher.resize(32, 0u8);
        cipher.extend_from_slice(&message[..]);
        let m = cipher.clone();

        curve25519xsalsa20poly1305::box_(&mut cipher, &m, &nonce, &pk.0, &sk.0);
        cipher.drain(..curve25519xsalsa20poly1305::BOX_ZERO_LEN); 

        Box { nonce: nonce, cipher: cipher }
}

impl CryptoBox {
    //Init a new crypto box from known keys
    pub fn from_key_pair(sender_key: SecretKey, recieve_key: PublicKey) -> CryptoBox {
        CryptoBox{ secret_key: sender_key, public_key: recieve_key }
    }

    //Encrypt a given message into the box
    //Sign a message using this box's secret key and encrypt the message to the given recipient's PublicKey.
    pub fn lock(&self, message: &[u8]) -> Box {      
        let mut nonce = [0u8; curve25519xsalsa20poly1305::NONCE_LEN];
        super::randombytes(&mut nonce);
        internal_lock(&message, nonce, &self.public_key, &self.secret_key)
    }

    //Decrypt a given message into plaintext
    /// `open()` verifies and decrypts a ciphertext `c` using the receiver's secret key `sk`,
    /// the senders public key `pk`, and a nonce `n`. It returns a plaintext `Ok(m)`.
    /// If the ciphertext fails verification, `open()` returns `Err(())`.
    pub fn unlock(&self, boxy: &Box) -> Option<Vec<u8>> {
        if boxy.cipher.len() < curve25519xsalsa20poly1305::BOX_ZERO_LEN { 
            println!("helloooooo");
            return None;
        }

        let mut plaintext = Vec::with_capacity(boxy.cipher.len() + curve25519xsalsa20poly1305::BOX_ZERO_LEN);
        plaintext.resize(curve25519xsalsa20poly1305::BOX_ZERO_LEN, 0u8); 
        plaintext.extend_from_slice(&boxy.cipher[..]);
        let m = plaintext.clone();

        match curve25519xsalsa20poly1305::box_open(&mut plaintext, &m, &boxy.nonce, &self.public_key.0, &self.secret_key.0) {
            Err(()) => None,
            Ok(()) => {
                plaintext.drain(..curve25519xsalsa20poly1305::ZERO_LEN);
                Some(plaintext)
            }
        }
    }

}



// #[test]
// fn test_lock_unlock() {
//     for i in 0..256usize {
//         let alice = Keypair::new();
//         let bob = Keypair::new();
//         //random message
//         let message = shared::random_data_test_helper(i);
//         println!("message: {:?}", message);
//         let alice_box = CryptoBox::from_key_pair(alice.secret, bob.public);
//         let bob_box = CryptoBox::from_key_pair(bob.secret, alice.public);

//         //lock from alice
//         let package = alice_box.lock(&message);
//         println!("before: {:?}", package.cipher);
//         //unlock from bob
//         let open_package = bob_box.unlock(&package);
        
//         println!("after: {:?}", open_package);
//         assert!(Some(message) == open_package);

//     }
// }

#[test]
fn test_vector_1() {
    // corresponding to tests/box.c and tests/box3.cpp from NaCl
    let alicesk = SecretKey([0x77, 0x07, 0x6d, 0x0a, 0x73, 0x18, 0xa5, 0x7d, 0x3c, 0x16,
                    0xc1, 0x72, 0x51, 0xb2, 0x66, 0x45, 0xdf, 0x4c, 0x2f, 0x87,
                    0xeb, 0xc0, 0x99, 0x2a, 0xb1, 0x77, 0xfb, 0xa5, 0x1d, 0xb9,
                    0x2c, 0x2a]);

    let bobpk = PublicKey([0xde, 0x9e, 0xdb, 0x7d, 0x7b, 0x7d, 0xc1, 0xb4, 0xd3, 0x5b, 0x61,
                    0xc2, 0xec, 0xe4, 0x35, 0x37, 0x3f, 0x83, 0x43, 0xc8, 0x5b, 0x78,
                    0x67, 0x4d, 0xad, 0xfc, 0x7e, 0x14, 0x6f, 0x88, 0x2b, 0x4f]);

    let boxy = Box {
        nonce: [0x69, 0x69, 0x6e, 0xe9, 0x55, 0xb6, 0x2b, 0x73, 0xcd, 0x62, 0xbd,
                    0xa8, 0x75, 0xfc, 0x73, 0xd6, 0x82, 0x19, 0xe0, 0x03, 0x6b, 0x7a,
                           0x0b, 0x37],

        cipher: vec![0xf3, 0xff, 0xc7, 0x70, 0x3f, 0x94, 0x00, 0xe5, 0x2a, 0x7d, 0xfb, 0x4b,
                        0x3d, 0x33, 0x05, 0xd9, 0x8e, 0x99, 0x3b, 0x9f, 0x48, 0x68, 0x12, 0x73,
                        0xc2, 0x96, 0x50, 0xba, 0x32, 0xfc, 0x76, 0xce, 0x48, 0x33, 0x2e, 0xa7,
                        0x16, 0x4d, 0x96, 0xa4, 0x47, 0x6f, 0xb8, 0xc5, 0x31, 0xa1, 0x18, 0x6a,
                        0xc0, 0xdf, 0xc1, 0x7c, 0x98, 0xdc, 0xe8, 0x7b, 0x4d, 0xa7, 0xf0, 0x11,
                        0xec, 0x48, 0xc9, 0x72, 0x71, 0xd2, 0xc2, 0x0f, 0x9b, 0x92, 0x8f, 0xe2,
                        0x27, 0x0d, 0x6f, 0xb8, 0x63, 0xd5, 0x17, 0x38, 0xb4, 0x8e, 0xee, 0xe3,
                        0x14, 0xa7, 0xcc, 0x8a, 0xb9, 0x32, 0x16, 0x45, 0x48, 0xe5, 0x26, 0xae,
                        0x90, 0x22, 0x43, 0x68, 0x51, 0x7a, 0xcf, 0xea, 0xbd, 0x6b, 0xb3, 0x73,
                        0x2b, 0xc0, 0xe9, 0xda, 0x99, 0x83, 0x2b, 0x61, 0xca, 0x01, 0xb6, 0xde,
                        0x56, 0x24, 0x4a, 0x9e, 0x88, 0xd5, 0xf9, 0xb3, 0x79, 0x73, 0xf6, 0x22,
                        0xa4, 0x3d, 0x14, 0xa6, 0x59, 0x9b, 0x1f, 0x65, 0x4c, 0xb4, 0x5a, 0x74,
                        0xe3, 0x55, 0xa5]
    };

    
    let m = [0xbe, 0x07, 0x5f, 0xc5,
        0x3c, 0x81, 0xf2, 0xd5, 0xcf, 0x14, 0x13, 0x16, 0xeb, 0xeb, 0x0c, 0x7b,
        0x52, 0x28, 0xc5, 0x2a, 0x4c, 0x62, 0xcb, 0xd4, 0x4b, 0x66, 0x84, 0x9b,
        0x64, 0x24, 0x4f, 0xfc, 0xe5, 0xec, 0xba, 0xaf, 0x33, 0xbd, 0x75, 0x1a,
        0x1a, 0xc7, 0x28, 0xd4, 0x5e, 0x6c, 0x61, 0x29, 0x6c, 0xdc, 0x3c, 0x01,
        0x23, 0x35, 0x61, 0xf4, 0x1d, 0xb6, 0x6c, 0xce, 0x31, 0x4a, 0xdb, 0x31,
        0x0e, 0x3b, 0xe8, 0x25, 0x0c, 0x46, 0xf0, 0x6d, 0xce, 0xea, 0x3a, 0x7f,
        0xa1, 0x34, 0x80, 0x57, 0xe2, 0xf6, 0x55, 0x6a, 0xd6, 0xb1, 0x31, 0x8a,
        0x02, 0x4a, 0x83, 0x8f, 0x21, 0xaf, 0x1f, 0xde, 0x04, 0x89, 0x77, 0xeb,
        0x48, 0xf5, 0x9f, 0xfd, 0x49, 0x24, 0xca, 0x1c, 0x60, 0x90, 0x2e, 0x52,
        0xf0, 0xa0, 0x89, 0xbc, 0x76, 0x89, 0x70, 0x40, 0xe0, 0x82, 0xf9, 0x37,
        0x76, 0x38, 0x48, 0x64, 0x5e, 0x07, 0x05 ];

    let c = internal_lock(&m, boxy.nonce, &bobpk, &alicesk);
     
    assert!(c.cipher == boxy.cipher);

}    

#[test]
fn test_vector_2() {
    // corresponding to tests/box2.c and tests/box4.cpp from NaCl
      
    let bobsk = SecretKey([0x5d, 0xab, 0x08, 0x7e, 0x62, 0x4a, 0x8a, 0x4b, 0x79, 0xe1, 0x7f,
                            0x8b, 0x83, 0x80, 0x0e, 0xe6, 0x6f, 0x3b, 0xb1, 0x29, 0x26, 0x18,
                            0xb6, 0xfd, 0x1c, 0x2f, 0x8b, 0x27, 0xff, 0x88, 0xe0, 0xeb]);

    let alicepk = PublicKey([0x85, 0x20, 0xf0, 0x09, 0x89, 0x30, 0xa7, 0x54, 0x74, 0x8b,
                            0x7d, 0xdc, 0xb4, 0x3e, 0xf7, 0x5a, 0x0d, 0xbf, 0x3a, 0x0d,
                            0x26, 0x38, 0x1a, 0xf4, 0xeb, 0xa4, 0xa9, 0x8e, 0xaa, 0x9b,
                            0x4e, 0x6a]);

    let boxy = Box {
        nonce: [0x69, 0x69, 0x6e, 0xe9, 0x55, 0xb6, 0x2b, 0x73, 0xcd, 0x62, 0xbd,
                0xa8, 0x75, 0xfc, 0x73, 0xd6, 0x82, 0x19, 0xe0, 0x03, 0x6b, 0x7a,
                0x0b, 0x37],
        
        cipher: vec![0xf3, 0xff, 0xc7, 0x70, 0x3f, 0x94, 0x00, 0xe5, 0x2a, 0x7d, 0xfb, 0x4b, 0x3d,
                 0x33, 0x05, 0xd9, 0x8e, 0x99, 0x3b, 0x9f, 0x48, 0x68, 0x12, 0x73, 0xc2, 0x96,
                 0x50, 0xba, 0x32, 0xfc, 0x76, 0xce, 0x48, 0x33, 0x2e, 0xa7, 0x16, 0x4d, 0x96,
                 0xa4, 0x47, 0x6f, 0xb8, 0xc5, 0x31, 0xa1, 0x18, 0x6a, 0xc0, 0xdf, 0xc1, 0x7c,
                 0x98, 0xdc, 0xe8, 0x7b, 0x4d, 0xa7, 0xf0, 0x11, 0xec, 0x48, 0xc9, 0x72, 0x71,
                 0xd2, 0xc2, 0x0f, 0x9b, 0x92, 0x8f, 0xe2, 0x27, 0x0d, 0x6f, 0xb8, 0x63, 0xd5,
                 0x17, 0x38, 0xb4, 0x8e, 0xee, 0xe3, 0x14, 0xa7, 0xcc, 0x8a, 0xb9, 0x32, 0x16,
                 0x45, 0x48, 0xe5, 0x26, 0xae, 0x90, 0x22, 0x43, 0x68, 0x51, 0x7a, 0xcf, 0xea,
                 0xbd, 0x6b, 0xb3, 0x73, 0x2b, 0xc0, 0xe9, 0xda, 0x99, 0x83, 0x2b, 0x61, 0xca,
                 0x01, 0xb6, 0xde, 0x56, 0x24, 0x4a, 0x9e, 0x88, 0xd5, 0xf9, 0xb3, 0x79, 0x73,
                 0xf6, 0x22, 0xa4, 0x3d, 0x14, 0xa6, 0x59, 0x9b, 0x1f, 0x65, 0x4c, 0xb4, 0x5a,
                 0x74, 0xe3, 0x55, 0xa5]
    };                        

    let bob_box = CryptoBox::from_key_pair(bobsk, alicepk);
    let res = bob_box.unlock(&boxy);

    let mexp = vec![0xbe, 0x07, 0x5f, 0xc5, 0x3c, 0x81, 0xf2, 0xd5, 0xcf, 0x14, 0x13,
                           0x16, 0xeb, 0xeb, 0x0c, 0x7b, 0x52, 0x28, 0xc5, 0x2a, 0x4c, 0x62,
                           0xcb, 0xd4, 0x4b, 0x66, 0x84, 0x9b, 0x64, 0x24, 0x4f, 0xfc, 0xe5,
                           0xec, 0xba, 0xaf, 0x33, 0xbd, 0x75, 0x1a, 0x1a, 0xc7, 0x28, 0xd4,
                           0x5e, 0x6c, 0x61, 0x29, 0x6c, 0xdc, 0x3c, 0x01, 0x23, 0x35, 0x61,
                           0xf4, 0x1d, 0xb6, 0x6c, 0xce, 0x31, 0x4a, 0xdb, 0x31, 0x0e, 0x3b,
                           0xe8, 0x25, 0x0c, 0x46, 0xf0, 0x6d, 0xce, 0xea, 0x3a, 0x7f, 0xa1,
                           0x34, 0x80, 0x57, 0xe2, 0xf6, 0x55, 0x6a, 0xd6, 0xb1, 0x31, 0x8a,
                           0x02, 0x4a, 0x83, 0x8f, 0x21, 0xaf, 0x1f, 0xde, 0x04, 0x89, 0x77,
                           0xeb, 0x48, 0xf5, 0x9f, 0xfd, 0x49, 0x24, 0xca, 0x1c, 0x60, 0x90,
                           0x2e, 0x52, 0xf0, 0xa0, 0x89, 0xbc, 0x76, 0x89, 0x70, 0x40, 0xe0,
                           0x82, 0xf9, 0x37, 0x76, 0x38, 0x48, 0x64, 0x5e, 0x07, 0x05];

  
        assert!(res == Some(mexp));
        // assert!(m_pre == mexp);
}