add sample

crypto/Cargo.lock

@@ -51,6 +51,7 @@ dependencies = [
  "p256",
  "p384",
  "p521",
+ "sha2",
 ]
 
 [[package]]

crypto/Cargo.toml

@@ -15,4 +15,5 @@ k256 = "0.2.0"
 p256 = "0.2.0"
 p384 = "0.1.0"
 p521 = "0.0.0"
+sha2 = "0.8.1"
 

crypto/src/main.rs

@@ -1,3 +1,31 @@
+use sha2::{Sha256, Sha512, Digest};
+
 fn main() {
-    println!("Hello, world!");
+    println!("{}", to_hex(&sha256(b"hello world")));
+    println!("{}", to_hex(&sha512(b"hello world")));
+}
+
+fn sha256(data: &[u8]) -> Vec<u8> {
+    let mut hasher = Sha256::new();
+    hasher.input(data);
+    let result = hasher.result();
+    result[..].to_vec()
+}
+
+fn sha512(data: &[u8]) -> Vec<u8> {
+    let mut hasher = Sha512::new();
+    hasher.input(data);
+    let result = hasher.result();
+    result[..].to_vec()
+}
+
+fn to_hex(bs: &[u8]) -> String {
+    bs.iter().map(|u| {
+        let x = format!("{:x}", u);
+        if x.len() == 1 {
+            "0".to_owned() + &x
+         } else {
+             x
+         }
+    }).collect()
 }