diff --git a/src/hashsum/digest.rs b/src/hashsum/digest.rs
new file mode 100644
index 000000000..e4d8356ec
--- /dev/null
+++ b/src/hashsum/digest.rs
@@ -0,0 +1,137 @@
+extern crate crypto;
+extern crate rustc_serialize;
+
+use crypto::md5::Md5;
+use crypto::sha1::Sha1;
+use crypto::sha2::{Sha224, Sha256, Sha384, Sha512};
+use crypto::sha3::Sha3;
+use crypto::digest::Digest as CryptoDigest;
+
+pub trait Digest {
+    fn input(&mut self, input: &[u8]);
+    fn result(&mut self, out: &mut [u8]);
+    fn reset(&mut self);
+    fn output_bits(&self) -> usize;
+    fn output_bytes(&self) -> usize {
+        (self.output_bits() + 7) / 8
+    }
+    fn result_str(&mut self) -> String {
+        use self::rustc_serialize::hex::ToHex;
+
+        let mut buf: Vec<u8> = vec![0; self.output_bytes()];
+        self.result(&mut buf);
+        buf.to_hex()
+    }
+}
+
+impl Digest for Md5 {
+    fn input(&mut self, input: &[u8]) {
+        CryptoDigest::input(self, input)
+    }
+
+    fn result(&mut self, out: &mut [u8]) {
+        CryptoDigest::result(self, out)
+    }
+
+    fn reset(&mut self) {
+        CryptoDigest::reset(self)
+    }
+
+    fn output_bits(&self) -> usize { CryptoDigest::output_bits(self) }
+}
+
+impl Digest for Sha1 {
+    fn input(&mut self, input: &[u8]) {
+        CryptoDigest::input(self, input)
+    }
+
+    fn result(&mut self, out: &mut [u8]) {
+        CryptoDigest::result(self, out)
+    }
+
+    fn reset(&mut self) {
+        CryptoDigest::reset(self)
+    }
+
+    fn output_bits(&self) -> usize { CryptoDigest::output_bits(self) }
+}
+
+impl Digest for Sha224 {
+    fn input(&mut self, input: &[u8]) {
+        CryptoDigest::input(self, input)
+    }
+
+    fn result(&mut self, out: &mut [u8]) {
+        CryptoDigest::result(self, out)
+    }
+
+    fn reset(&mut self) {
+        CryptoDigest::reset(self)
+    }
+
+    fn output_bits(&self) -> usize { CryptoDigest::output_bits(self) }
+}
+
+impl Digest for Sha256 {
+    fn input(&mut self, input: &[u8]) {
+        CryptoDigest::input(self, input)
+    }
+
+    fn result(&mut self, out: &mut [u8]) {
+        CryptoDigest::result(self, out)
+    }
+
+    fn reset(&mut self) {
+        CryptoDigest::reset(self)
+    }
+
+    fn output_bits(&self) -> usize { CryptoDigest::output_bits(self) }
+}
+
+impl Digest for Sha384 {
+    fn input(&mut self, input: &[u8]) {
+        CryptoDigest::input(self, input)
+    }
+
+    fn result(&mut self, out: &mut [u8]) {
+        CryptoDigest::result(self, out)
+    }
+
+    fn reset(&mut self) {
+        CryptoDigest::reset(self)
+    }
+
+    fn output_bits(&self) -> usize { CryptoDigest::output_bits(self) }
+}
+
+impl Digest for Sha512 {
+    fn input(&mut self, input: &[u8]) {
+        CryptoDigest::input(self, input)
+    }
+
+    fn result(&mut self, out: &mut [u8]) {
+        CryptoDigest::result(self, out)
+    }
+
+    fn reset(&mut self) {
+        CryptoDigest::reset(self)
+    }
+
+    fn output_bits(&self) -> usize { CryptoDigest::output_bits(self) }
+}
+
+impl Digest for Sha3 {
+    fn input(&mut self, input: &[u8]) {
+        CryptoDigest::input(self, input)
+    }
+
+    fn result(&mut self, out: &mut [u8]) {
+        CryptoDigest::result(self, out)
+    }
+
+    fn reset(&mut self) {
+        CryptoDigest::reset(self)
+    }
+
+    fn output_bits(&self) -> usize { CryptoDigest::output_bits(self) }
+}
diff --git a/src/hashsum/hashsum.rs b/src/hashsum/hashsum.rs
index af47432a6..8579a2ddb 100644
--- a/src/hashsum/hashsum.rs
+++ b/src/hashsum/hashsum.rs
@@ -20,7 +20,9 @@ extern crate rustc_serialize as serialize;
 #[macro_use]
 extern crate uucore;
 
-use crypto::digest::Digest;
+mod digest;
+
+use digest::Digest;
 use crypto::md5::Md5;
 use crypto::sha1::Sha1;
 use crypto::sha2::{Sha224, Sha256, Sha384, Sha512};