Implement challenge 33 Diffie-Hellman

src/rsa.rs

@@ -0,0 +1,12 @@
+pub fn expmod(base: u32, exp: u32, m: u32) -> u32 {
+    if exp == 0 {
+        return 1;
+    }
+
+    if exp % 2 == 0 {
+        let s = expmod(base, exp / 2, m);
+        (s * s) % m
+    } else {
+        (expmod(base, exp - 1, m) * base) % m
+    }
+}