Add a wrapper for prove, verify and param derivation. (#73)

## Content

A simple wrapper struct around `prove()` and `verify()` functions and
parameter derivation.

## Pre-submit checklist

- Branch
    - [x] Tests are provided (if possible)
    - [x] Commit sequence broadly makes sense
    - [x] Key commits have useful messages
- PR
    - [x] No clippy warnings in the CI
    - [x] Self-reviewed the diff
    - [x] Useful pull request description
    - [x] Reviewer requested
- Documentation
    - [x] Update README file (if relevant)
    - [x] Update documentation website (if relevant)

## Issue(s)

Relates to #66

src/centralized_telescope/algorithm.rs

@@ -11,14 +11,14 @@ use blake2::{Blake2s256, Digest};
 /// Alba's proving algorithm, based on a depth-first search algorithm.
 /// Calls up to setup.max_retries times the prove_index function and returns an empty
 /// proof if no suitable candidate is found.
-pub fn prove(setup: &Setup, prover_set: &[Element]) -> Option<Proof> {
+pub(super) fn prove(setup: &Setup, prover_set: &[Element]) -> Option<Proof> {
     // Run prove_index up to max_retries times
     (0..setup.max_retries).find_map(|retry_counter| prove_index(setup, prover_set, retry_counter).1)
 }
 
 /// Alba's verification algorithm, returns true if the proof is
 /// successfully verified, following the DFS verification, false otherwise.
-pub fn verify(setup: &Setup, proof: &Proof) -> bool {
+pub(super) fn verify(setup: &Setup, proof: &Proof) -> bool {
     if proof.search_counter >= setup.search_width
         || proof.retry_counter >= setup.max_retries
         || proof.element_sequence.len() as u64 != setup.proof_size

src/centralized_telescope/mod.rs

@@ -1,7 +1,7 @@
 //! ALBA's bounded DFS scheme using Blake2b as hash function.
 //! (c.f. Section 3.2.2 of Alba paper)
 
-pub mod algorithm;
+mod algorithm;
 
 pub mod init;
 
@@ -14,3 +14,8 @@ mod round;
 pub mod setup;
 
 mod types;
+
+mod wrapper;
+
+// Re-exports
+pub use wrapper::Wrapper as CentralizedTelescope;

src/centralized_telescope/wrapper.rs

@@ -0,0 +1,38 @@
+use super::algorithm;
+use super::init::make_setup;
+use super::params::Params;
+use super::proof::Proof;
+use super::setup::Setup;
+use crate::utils::types::Element;
+
+/// The main ALBA struct with prove and verify functions.
+#[derive(Debug, Clone, Copy)]
+pub struct Wrapper {
+    setup: Setup,
+}
+
+impl Wrapper {
+    /// Initialize ALBA with `Params`.
+    pub fn create(params: &Params) -> Self {
+        let setup = make_setup(params);
+        Self::create_unsafe(&setup)
+    }
+
+    /// This function is unsafe to use and should be avoided.
+    /// Initialize ALBA with `Setup`.
+    pub fn create_unsafe(setup: &Setup) -> Self {
+        Self { setup: *setup }
+    }
+
+    /// Alba's proving algorithm, based on a depth-first search algorithm.
+    /// Returns either a `Proof` or `None` if no proof is found.
+    pub fn prove(&self, prover_set: &[Element]) -> Option<Proof> {
+        algorithm::prove(&self.setup, prover_set)
+    }
+
+    /// Alba's verification algorithm.
+    /// Returns true if and only if the proof is successfully verified.
+    pub fn verify(&self, proof: &Proof) -> bool {
+        algorithm::verify(&self.setup, proof)
+    }
+}