openpgp: New function crypto::random.

  - Add and use a function that fills a buffer with a thread-local
    random number generator.

4 files changed, 12 insertions, 10 deletions

diff --git a/openpgp/src/crypto/aead.rs b/openpgp/src/crypto/aead.rs
index b6ca09d3..2c16ffc0 100644
--- a/openpgp/src/crypto/aead.rs
+++ b/openpgp/src/crypto/aead.rs
@@ -754,8 +754,6 @@ mod tests {
     #[test]
     fn roundtrip() {
         use std::io::Cursor;
-        use nettle::{Random, Yarrow};
-        let mut rng = Yarrow::default();
 
         for sym_algo in [SymmetricAlgorithm::AES128,
                          SymmetricAlgorithm::AES192,
@@ -768,10 +766,10 @@ mod tests {
                 let version = 1;
                 let chunk_size = 64;
                 let mut key = vec![0; sym_algo.key_size().unwrap()];
-                rng.random(&mut key);
+                ::crypto::random(&mut key);
                 let key: SessionKey = key.into();
                 let mut iv = vec![0; aead.iv_size().unwrap()];
-                rng.random(&mut iv);
+                ::crypto::random(&mut iv);
 
                 let mut ciphertext = Vec::new();
                 {
diff --git a/openpgp/src/crypto/mod.rs b/openpgp/src/crypto/mod.rs
index 5a6b06c0..6645ecdc 100644
--- a/openpgp/src/crypto/mod.rs
+++ b/openpgp/src/crypto/mod.rs
@@ -27,6 +27,13 @@ pub use self::asymmetric::{
     KeyPair,
 };
 
+/// Fills the given buffer with random data.
+pub fn random<B: AsMut<[u8]>>(mut buf: B) {
+    use std::cell::RefCell;
+    thread_local!(static RNG: RefCell<Yarrow> = Default::default());
+    RNG.with(|rng| rng.borrow_mut().random(buf.as_mut()));
+}
+
 /// Holds a session key.
 ///
 /// The session key is cleared when dropped.
@@ -37,7 +44,7 @@ impl SessionKey {
     /// Creates a new session key.
     pub fn new(size: usize) -> Self {
         let mut sk: mem::Protected = vec![0; size].into();
-        Yarrow::default().random(&mut sk);
+        random(&mut sk);
         Self(sk)
     }
 
diff --git a/openpgp/src/crypto/s2k.rs b/openpgp/src/crypto/s2k.rs
index b3e099e2..b2b95f68 100644
--- a/openpgp/src/crypto/s2k.rs
+++ b/openpgp/src/crypto/s2k.rs
@@ -14,7 +14,6 @@ use crypto::SessionKey;
 
 use std::fmt;
 
-use nettle::{Yarrow, Random};
 use quickcheck::{Arbitrary, Gen};
 use rand::Rng;
 
@@ -57,7 +56,7 @@ pub enum S2K {
 impl Default for S2K {
     fn default() -> Self {
         let mut salt = [0u8; 8];
-        Yarrow::default().random(&mut salt);
+        ::crypto::random(&mut salt);
         S2K::Iterated {
             // SHA2-256, being optimized for implementations on
             // architectures with a word size of 32 bit, has a more
diff --git a/openpgp/src/crypto/symmetric.rs b/openpgp/src/crypto/symmetric.rs
index d2a94b15..32183163 100644
--- a/openpgp/src/crypto/symmetric.rs
+++ b/openpgp/src/crypto/symmetric.rs
@@ -583,8 +583,6 @@ mod tests {
     #[test]
     fn roundtrip() {
         use std::io::Cursor;
-        use nettle::{Random, Yarrow};
-        let mut rng = Yarrow::default();
 
         for algo in [SymmetricAlgorithm::TripleDES,
                      SymmetricAlgorithm::CAST5,
@@ -597,7 +595,7 @@ mod tests {
                      SymmetricAlgorithm::Camellia192,
                      SymmetricAlgorithm::Camellia256].iter() {
             let mut key = vec![0; algo.key_size().unwrap()];
-            rng.random(&mut key);
+            ::crypto::random(&mut key);
 
             let mut ciphertext = Vec::new();
             {