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
119
120
121
122
123
124
125
126
127
128
129

use crate::Hasher;

pub use fuel_types::Bytes32;

use core::fmt;
use core::ops::Deref;

/// Normalized signature message
#[derive(Default, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
#[cfg_attr(
    feature = "serde-types-minimal",
    derive(serde::Serialize, serde::Deserialize)
)]
#[repr(transparent)]
pub struct Message(Bytes32);

impl Message {
    /// Memory length of the type
    pub const LEN: usize = Bytes32::LEN;

    /// Normalize a message for signature
    pub fn new<M>(message: M) -> Self
    where
        M: AsRef<[u8]>,
    {
        Self(Hasher::hash(message))
    }

    /// Add a conversion from arbitrary slices into owned
    ///
    /// # Safety
    ///
    /// There is no guarantee the provided bytes will be the product of a cryptographically secure
    /// hash. Using insecure messages might compromise the security of the signature.
    pub unsafe fn from_bytes_unchecked(bytes: [u8; Self::LEN]) -> Self {
        Self(bytes.into())
    }

    /// Add a conversion from arbitrary slices into owned
    ///
    /// # Safety
    ///
    /// This function will not panic if the length of the slice is smaller than
    /// `Self::LEN`. Instead, it will cause undefined behavior and read random
    /// disowned bytes.
    ///
    /// This function extends the unsafety of [`Self::from_bytes_unchecked`].
    pub unsafe fn from_slice_unchecked(bytes: &[u8]) -> Self {
        Self(Bytes32::from_slice_unchecked(bytes))
    }

    /// Copy-free reference cast
    ///
    /// # Safety
    ///
    /// Inputs smaller than `Self::LEN` will cause undefined behavior.
    ///
    /// This function extends the unsafety of [`Self::from_bytes_unchecked`].
    pub unsafe fn as_ref_unchecked(bytes: &[u8]) -> &Self {
        // The interpreter will frequently make references to keys and values using
        // logically checked slices.
        //
        // This function will avoid unnecessary copy to owned slices for the interpreter
        // access
        &*(bytes.as_ptr() as *const Self)
    }
}

impl Deref for Message {
    type Target = [u8; Message::LEN];

    fn deref(&self) -> &[u8; Message::LEN] {
        self.0.deref()
    }
}

impl AsRef<[u8]> for Message {
    fn as_ref(&self) -> &[u8] {
        self.0.as_ref()
    }
}

impl From<Message> for [u8; Message::LEN] {
    fn from(message: Message) -> [u8; Message::LEN] {
        message.0.into()
    }
}

impl fmt::LowerHex for Message {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        self.0.fmt(f)
    }
}

impl fmt::UpperHex for Message {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        self.0.fmt(f)
    }
}

impl fmt::Debug for Message {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        self.0.fmt(f)
    }
}

impl fmt::Display for Message {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        self.0.fmt(f)
    }
}

#[cfg(feature = "std")]
mod use_std {
    use crate::Message;

    use secp256k1::Message as Secp256k1Message;

    impl Message {
        pub(crate) fn to_secp(&self) -> Secp256k1Message {
            // The only validation performed by `Message::from_slice` is to check if it is
            // 32 bytes. This validation exists to prevent users from signing
            // non-hashed messages, which is a severe violation of the protocol
            // security.
            debug_assert_eq!(Self::LEN, secp256k1::constants::MESSAGE_SIZE);
            Secp256k1Message::from_slice(self.as_ref()).expect("Unreachable error")
        }
    }
}