wip on RLWE

sampling/src/source.rs

@@ -1,6 +1,6 @@
 use rand_chacha::rand_core::SeedableRng;
 use rand_chacha::ChaCha8Rng;
-use rand_core::RngCore;
+use rand_core::{OsRng, RngCore};
 
 const MAXF64: f64 = 9007199254740992.0;
 
@@ -8,6 +8,12 @@ pub struct Source {
     source: ChaCha8Rng,
 }
 
+pub fn new_seed() -> [u8; 32] {
+    let mut seed = [0u8; 32];
+    OsRng.fill_bytes(&mut seed);
+    seed
+}
+
 impl Source {
     pub fn new(seed: [u8; 32]) -> Source {
         Source {
@@ -21,6 +27,10 @@ impl Source {
         seed
     }
 
+    pub fn branch(&mut self) -> Self {
+        Source::new(self.new_seed())
+    }
+
     #[inline(always)]
     pub fn next_u64n(&mut self, max: u64, mask: u64) -> u64 {
         let mut x: u64 = self.next_u64() & mask;