rust: Add crypto crate and implement Rust wrappers for SHA2 code.

 * FIXES #24659: https://bugs.torproject.org/24659

1 files changed, 36 insertions, 0 deletions

diff --git a/src/rust/crypto/lib.rs b/src/rust/crypto/lib.rs
new file mode 100644
index 0000000000..d0793a8575
--- /dev/null
+++ b/src/rust/crypto/lib.rs
@@ -0,0 +1,36 @@
+// Copyright (c) 2018, The Tor Project, Inc.
+// Copyright (c) 2018, isis agora lovecruft
+// See LICENSE for licensing information
+
+//! Common cryptographic functions and utilities.
+//!
+//! # Hash Digests and eXtendable Output Functions (XOFs)
+//!
+//! The `digests` module contains submodules for specific hash digests
+//! and extendable output functions.
+//!
+//! ```
+//! use crypto::digests::sha256::Sha256;
+//!
+//! let hasher: Sha256 = Sha256::default();
+//! let mut result: [u8; 32] = [0u8; 32];
+//!
+//! hasher.input("foo");
+//! hasher.input("bar");
+//! hasher.input("baz");
+//!
+//! result.copy_from_slice(hasher.result().as_bytes());
+//!
+//! assert!(result == "XXX");
+//! ```
+
+#[deny(missing_docs)]
+
+// External crates from cargo or TOR_RUST_DEPENDENCIES.
+extern crate digest;
+extern crate libc;
+
+// Our local crates.
+extern crate external;
+
+mod digests;  // Unfortunately named "digests" plural to avoid name conflict with the digest crate