Initial commit

crypto/src/lib.rs

@@ -0,0 +1,56 @@
+extern crate failure;
+extern crate hex;
+extern crate ring;
+
+#[cfg(test)]
+#[macro_use]
+extern crate proptest;
+
+use failure::Error;
+use hex::{FromHex, ToHex};
+use ring::{digest, hmac};
+
+type Result<T> = std::result::Result<T, Error>;
+
+pub fn bytes_to_hex_str(bytes: &[u8]) -> Result<String> {
+    let mut output = String::new();
+    bytes.write_hex(&mut output)?;
+    Ok(output)
+}
+
+pub fn hex_str_to_bytes(hex_str: &str) -> Result<Vec<u8>> {
+    Ok(Vec::from_hex(hex_str)?)
+}
+
+pub fn verify_signature(key: &[u8], msg: &[u8], signature: &[u8]) -> bool {
+    let key = hmac::VerificationKey::new(&digest::SHA256, key);
+    hmac::verify(&key, msg, signature)
+        .map(|_| true)
+        .unwrap_or(false)
+}
+
+pub fn sign(key: &[u8], msg: &[u8]) -> Vec<u8> {
+    let key = hmac::SigningKey::new(&digest::SHA256, key);
+    let signature = hmac::sign(&key, msg);
+    signature.as_ref().into_iter().cloned().collect()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    proptest! {
+        #[test]
+        fn sign_verify(key: Vec<u8>, msg: Vec<u8>) {
+            let sig = sign(&key, &msg);
+            assert!(verify_signature(&key, &msg, &sig));
+        }
+    }
+
+    proptest! {
+        #[test]
+        fn to_from_hex(data: Vec<u8>) {
+            assert_eq!(hex_str_to_bytes(&bytes_to_hex_str(&data).unwrap()).unwrap(), data);
+        }
+    }
+}