Added clonability for sha hash state. Useful for incremental hashing

openssl-sys/src/sha.rs

@@ -5,6 +5,7 @@ pub type SHA_LONG = c_uint;
 pub const SHA_LBLOCK: c_int = 16;
 
 #[repr(C)]
+#[derive(Clone)]
 pub struct SHA_CTX {
     pub h0: SHA_LONG,
     pub h1: SHA_LONG,

openssl/src/sha.rs

@@ -110,6 +110,7 @@ pub fn sha512(data: &[u8]) -> [u8; 64] {
 ///
 /// SHA1 is known to be insecure - it should not be used unless required for
 /// compatibility with existing systems.
+#[derive(Clone)]
 pub struct Sha1(ffi::SHA_CTX);
 
 impl Sha1 {