1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118

use crate::crypto::pbkdf2;
use crate::keyphrase::KeyPhrase;
use std::fmt;

/// The secret value used to derive HD wallet addresses from a [`KeyPhrase`][KeyPhrase] phrase.
///
/// Because it is not possible to create a [`KeyPhrase`][KeyPhrase] instance that is invalid, it is
/// therefore impossible to have a [`Seed`][Seed] instance that is invalid. This guarantees that only
/// a valid, intact KeyPhrase can be used to derive HD wallet addresses.
///
/// To get the raw byte value use [`Seed::as_bytes()`][Seed::as_bytes()]. These can be used to derive
/// HD wallet addresses using another crate (deriving HD wallet addresses is outside the scope of this
/// crate and the BIP39 standard).
///
/// [KeyPhrase]: ./keyphrase/struct.KeyPhrase.html
/// [Seed]: ./seed/struct.Seed.html
/// [Seed::as_bytes()]: ./seed/struct.Seed.html#method.as_bytes

#[derive(Clone)]
pub struct Seed {
    bytes: Vec<u8>,
}

impl Seed {
    /// Generates the seed from the [`KeyPhrase`][KeyPhrase] and the password.
    ///
    /// [KeyPhrase]: ./keyphrase/struct.KeyPhrase.html
    ///
    /// # Example
    ///
    /// ```
    /// use keyphrase::{KeyPhrase, KeyPhraseType, Language, Seed};
    ///
    /// let word_count: KeyPhraseType = KeyPhraseType::Words15;
    ///
    /// let lang: Language = Language::English;
    ///
    /// let keyphrase: KeyPhrase = KeyPhrase::new(word_count, lang);
    ///
    /// let seed: Seed = Seed::new(&keyphrase, "");
    /// ```
    pub fn new(keyphrase: &KeyPhrase, password: &str) -> Self {
        let salt: String = format!("keyphrase{}", password);
        let bytes: Vec<u8> = pbkdf2(keyphrase.entropy(), &salt);

        Self { bytes }
    }

    /// Get the seed value as a byte slice
    ///
    /// # Example
    ///
    /// ```
    /// use keyphrase::{KeyPhrase, KeyPhraseType, Language, Seed};
    ///
    /// let word_count: KeyPhraseType = KeyPhraseType::Words15;
    ///
    /// let lang: Language = Language::English;
    ///
    /// let keyphrase: KeyPhrase = KeyPhrase::new(word_count, lang);
    ///
    /// let seed: Seed = Seed::new(&keyphrase, "");
    ///     
    /// let seed_bytes: &[u8] = seed.as_bytes();
    /// ```
    pub fn as_bytes(&self) -> &[u8] {
        &self.bytes
    }
}

impl AsRef<[u8]> for Seed {
    fn as_ref(&self) -> &[u8] {
        self.as_bytes()
    }
}

impl fmt::Debug for Seed {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "{:#X}", self)
    }
}

impl fmt::LowerHex for Seed {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        if f.alternate() {
            f.write_str("0x")?;
        }

        for byte in &self.bytes {
            write!(f, "{:x}", byte)?;
        }

        Ok(())
    }
}

impl fmt::UpperHex for Seed {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        if f.alternate() {
            f.write_str("0x")?;
        }

        // TODO - Why are values which are less than 10 (in base 10) dropping the leading 0 when converted to hex?
        // Ex: 03 becomes 3 which is causing the final seed string to be odd numbers. Is this an issue?
        // for byte in &self.bytes {
        //     if byte < &10 {
        //         write!(f, "0{:X}", byte)?;
        //     } else {
        //         write!(f, "{:X}", byte)?;
        //     }
        // }

        for byte in &self.bytes {
            write!(f, "{:X}", byte)?;
        }
        Ok(())
    }
}