Adding a working bft-json-crdt implementation for the PoC

crates/bft-json-crdt/src/keypair.rs

@@ -0,0 +1,57 @@
+use fastcrypto::traits::VerifyingKey;
+pub use fastcrypto::{
+    ed25519::{
+        Ed25519KeyPair, Ed25519PublicKey, Ed25519Signature, ED25519_PUBLIC_KEY_LENGTH,
+        ED25519_SIGNATURE_LENGTH,
+    },
+    traits::{KeyPair, Signer},
+    // Verifier,
+};
+use sha2::{Digest, Sha256};
+
+/// Represents the ID of a unique node. An Ed25519 public key
+pub type AuthorId = [u8; ED25519_PUBLIC_KEY_LENGTH];
+
+/// A signed message
+pub type SignedDigest = [u8; ED25519_SIGNATURE_LENGTH];
+
+/// Create a fake public key from a u8
+pub fn make_author(n: u8) -> AuthorId {
+    let mut id = [0u8; ED25519_PUBLIC_KEY_LENGTH];
+    id[0] = n;
+    id
+}
+
+/// Get the least significant 32 bits of a public key
+pub fn lsb_32(pubkey: AuthorId) -> u32 {
+    ((pubkey[0] as u32) << 24)
+        + ((pubkey[1] as u32) << 16)
+        + ((pubkey[2] as u32) << 8)
+        + (pubkey[3] as u32)
+}
+
+/// SHA256 hash of a string
+pub fn sha256(input: String) -> [u8; 32] {
+    let mut hasher = Sha256::new();
+    hasher.update(input.as_bytes());
+    let result = hasher.finalize();
+    let mut bytes = [0u8; 32];
+    bytes.copy_from_slice(&result[..]);
+    bytes
+}
+
+/// Generate a random Ed25519 keypair from OS rng
+pub fn make_keypair() -> Ed25519KeyPair {
+    let mut csprng = rand::thread_rng();
+    Ed25519KeyPair::generate(&mut csprng)
+}
+
+/// Sign a byte array
+pub fn sign(keypair: &Ed25519KeyPair, message: &[u8]) -> Ed25519Signature {
+    keypair.sign(message)
+}
+
+/// Verify a byte array was signed by the given pubkey
+pub fn verify(pubkey: Ed25519PublicKey, message: &[u8], signature: Ed25519Signature) -> bool {
+    pubkey.verify(message, &signature).is_ok()
+}