Implement CryptoRng for ReseedingRng

Author: pitdicker

rand-core/src/lib.rs

@@ -203,7 +203,7 @@ pub trait BlockRngCore<T>: Sized {
 /// 
 /// Note also that use of a `CryptoRng` does not protect against other
 /// weaknesses such as seeding from a weak entropy source or leaking state.
-pub trait CryptoRng: RngCore {}
+pub trait CryptoRng {}
 
 /// A random number generator that can be explicitly seeded.
 ///

src/prng/chacha.rs

@@ -286,6 +286,8 @@ impl SeedableRng for ChaChaCore {
     }
 }
 
+impl CryptoRng for ChaChaCore {}
+
 #[cfg(test)]
 mod test {
     use {RngCore, SeedableRng};

src/prng/hc128.rs

@@ -96,6 +96,8 @@ impl SeedableRng for Hc128Rng {
     }
 }
 
+impl CryptoRng for Hc128Rng {}
+
 #[derive(Clone)]
 pub struct Hc128Core {
     t: [u32; 1024],
@@ -309,8 +311,6 @@ impl Hc128Core {
     }
 }
 
-impl CryptoRng for Hc128Rng {}
-
 impl SeedableRng for Hc128Core {
     type Seed = [u8; SEED_WORDS*4];
 
@@ -324,6 +324,8 @@ impl SeedableRng for Hc128Core {
     }
 }
 
+impl CryptoRng for Hc128Core {}
+
 #[cfg(test)]
 mod test {
     use {RngCore, SeedableRng};

src/reseeding.rs

@@ -11,7 +11,7 @@
 //! A wrapper around another PRNG that reseeds it after it
 //! generates a certain number of random bytes.
 
-use rand_core::{RngCore, BlockRngCore, SeedableRng, Error, ErrorKind};
+use rand_core::{RngCore, BlockRngCore, CryptoRng, SeedableRng, Error, ErrorKind};
 use rand_core::impls::BlockRng;
 
 /// A wrapper around any PRNG which reseeds the underlying PRNG after it has
@@ -117,6 +117,10 @@ impl<R: BlockRngCore<u32> + SeedableRng, Rsdr: RngCore> RngCore for ReseedingRng
     }
 }
 
+impl<R, Rsdr> CryptoRng for ReseedingRng<R, Rsdr>
+where R: BlockRngCore<u32> + SeedableRng + CryptoRng,
+      Rsdr: RngCore + CryptoRng {}
+
 #[derive(Debug)]
 struct ReseedingCore<R, Rsdr> {
     inner: R,
@@ -197,6 +201,10 @@ where R: BlockRngCore<u32> + SeedableRng,
     }
 }
 
+impl<R, Rsdr> CryptoRng for ReseedingCore<R, Rsdr>
+where R: BlockRngCore<u32> + SeedableRng + CryptoRng,
+      Rsdr: RngCore + CryptoRng {}
+
 #[cfg(test)]
 mod test {
     use {Rng, SeedableRng};