LibCrypto: Add a Hash::Manager that can act as any one of the hashes

Author: https://github.com/alimpfard
Commit: 43a49f5fff
Pull-request: https://github.com/SerenityOS/serenity/pull/1661
Reviewed-by: https://github.com/Dexesttp
Reviewed-by: https://github.com/awesomekling
Reviewed-by: https://github.com/itamar8910

Libraries/LibCrypto/Hash/SHA1.h

@@ -48,6 +48,10 @@ constexpr static u32 RoundConstants[4] {
 template<size_t Bytes>
 struct SHA1Digest {
     u8 data[Bytes];
+    constexpr static size_t Size = Bytes;
+
+    const u8* immutable_data() const { return data; }
+    size_t data_length() { return Bytes; }
 };
 
 class SHA1 final : public HashFunction<512, SHA1Digest<160 / 8>> {