add borromean + fix mlsag

coins/monero/src/ringct/borromean.rs

@@ -0,0 +1,54 @@
+#![allow(non_snake_case)]
+
+use std::fmt::Debug;
+use std::io::{self, Read, Write};
+
+use curve25519_dalek::edwards::EdwardsPoint;
+use curve25519_dalek::scalar::Scalar;
+
+use crate::serialize::*;
+
+fn read_64_array<R: Read, T: Debug, F: Fn(&mut R) -> io::Result<T>>(
+  f: F,
+  r: &mut R,
+) -> io::Result<[T; 64]> {
+  (0 .. 64).map(|_| f(r)).collect::<io::Result<Vec<T>>>().map(|vec| vec.try_into().unwrap())
+}
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct BorroSig {
+  pub s0: [Scalar; 64],
+  pub s1: [Scalar; 64],
+  pub ee: Scalar,
+}
+
+impl BorroSig {
+  pub fn read<R: Read>(r: &mut R) -> io::Result<BorroSig> {
+    Ok(BorroSig {
+      s0: read_64_array(read_scalar, r)?,
+      s1: read_64_array(read_scalar, r)?,
+      ee: read_scalar(r)?,
+    })
+  }
+  pub fn write<W: Write>(&self, w: &mut W) -> io::Result<()> {
+    write_raw_vec(write_scalar, &self.s0, w)?;
+    write_raw_vec(write_scalar, &self.s1, w)?;
+    write_scalar(&self.ee, w)
+  }
+}
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct RangeSig {
+  pub asig: BorroSig,
+  pub Ci: [EdwardsPoint; 64],
+}
+
+impl RangeSig {
+  pub fn read<R: Read>(r: &mut R) -> io::Result<RangeSig> {
+    Ok(RangeSig { asig: BorroSig::read(r)?, Ci: read_64_array(read_point, r)? })
+  }
+  pub fn write<W: Write>(&self, w: &mut W) -> io::Result<()> {
+    self.asig.write(w)?;
+    write_raw_vec(write_point, &self.Ci, w)
+  }
+}