- remove dependency on hex-literal crate
- add helper for converting between hex strings and bytes

Change-Id: I073b597cfb1b2687dd7d1743441bdfaaf601810d
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/58225
Reviewed-by: Bob Beck <bbe@google.com>
Commit-Queue: Bob Beck <bbe@google.com>
diff --git a/rust/bssl-crypto/src/lib.rs b/rust/bssl-crypto/src/lib.rs
index 9c4a214..8400337 100644
--- a/rust/bssl-crypto/src/lib.rs
+++ b/rust/bssl-crypto/src/lib.rs
@@ -37,6 +37,9 @@
 /// BoringSSL implemented hmac operations.
 pub mod hmac;
 
+#[cfg(test)]
+mod test_helpers;
+
 /// This is a helper struct which provides functions for passing slices over FFI.
 struct CSlice<'a>(&'a [u8]);