Adding serialization and docs (#6)

src/ciphersuite.rs

@@ -5,33 +5,11 @@
 
 //! Defines the CipherSuite trait to specify the underlying primitives for VOPRF
 
-use crate::{errors::InternalError, group::Group, hash::Hash};
-
-static STR_VOPRF: &[u8] = b"VOPRF07-";
-
-pub enum Mode {
-    Base = 0,
-    Verifiable = 1,
-}
-
 /// Configures the underlying primitives used in VOPRF
 pub trait CipherSuite {
     /// A finite cyclic group along with a point representation that allows some
     /// customization on how to hash an input to a curve point. See `group::Group`.
-    type Group: Group;
+    type Group: crate::group::Group;
     /// The main hash function to use (for HKDF computations and hashing transcripts).
-    type Hash: Hash;
-
-    /// Generates the contextString parameter as defined in
-    /// <https://www.ietf.org/archive/id/draft-irtf-cfrg-voprf-07.html>
-    fn get_context_string(mode: Mode) -> Result<alloc::vec::Vec<u8>, InternalError> {
-        use crate::serialization::i2osp;
-
-        Ok([
-            STR_VOPRF,
-            &i2osp(mode as usize, 1)?,
-            &i2osp(Self::Group::SUITE_ID, 2)?,
-        ]
-        .concat())
-    }
+    type Hash: crate::hash::Hash;
 }