Changes to make the rust crypto::mod tests compile

The digest tests don't link yet, though.

src/rust/crypto/lib.rs

@@ -29,9 +29,17 @@
 // External crates from cargo or TOR_RUST_DEPENDENCIES.
 extern crate digest;
 extern crate libc;
+extern crate rand_core;
+
+// External dependencies for tests.
+#[cfg(test)]
+extern crate rand as rand_crate;
 
 // Our local crates.
 extern crate external;
+#[cfg(not(test))]
+#[macro_use]
+extern crate tor_log;
 
 pub mod digests;  // Unfortunately named "digests" plural to avoid name conflict with the digest crate
 pub mod rand;

src/rust/crypto/rand/mod.rs

@@ -2,15 +2,5 @@
 // Copyright (c) 2018, isis agora lovecruft
 // See LICENSE for licensing information
 
-// External dependencies
-#[cfg(test)]
-extern crate rand;
-extern crate rand_core;
-
 // Internal dependencies
-extern crate external;
-#[cfg(not(test))]
-#[macro_use]
-extern crate tor_log;
-
 pub mod rng;

src/rust/crypto/rand/rng.rs

@@ -130,8 +130,8 @@ mod internal {
 #[cfg(test)]
 mod internal {
     // It doesn't matter if we pretend ChaCha is a CSPRNG in tests.
-    pub use rand::ChaChaRng as TorRng;
-    pub use rand::ChaChaRng as TorStrongestRng;
+    pub use rand_crate::ChaChaRng as TorRng;
+    pub use rand_crate::ChaChaRng as TorStrongestRng;
 }
 
 // Finally, expose the public functionality of whichever appropriate internal