refactor: split the library into fumi-core and make it embeddable

core/src/vectors.rs

@@ -0,0 +1,119 @@
+//! The committed reference vectors (`vectors.json`) as the tests' source of
+//! truth, so the file and the derivations cannot drift apart. Language ports
+//! and FFI bindings pin the same operations against the same file without
+//! regenerating anything from the reference stack.
+
+use serde::Deserialize;
+
+use crate::crypto::KEY_LEN;
+
+#[derive(Deserialize)]
+pub struct Vectors {
+    /// The master every derivation below starts from, hex-encoded.
+    pub master_hex: String,
+    /// `identity_seed(master, n)` per rotation index, base32.
+    pub identity_seeds_b32: std::collections::BTreeMap<String, String>,
+    /// `Identity::from_seed(seed_n).pk()` per rotation index, base32.
+    pub identity_pks_b32: std::collections::BTreeMap<String, String>,
+    /// The X25519 half per rotation index, base32.
+    pub identity_xprivs_b32: std::collections::BTreeMap<String, String>,
+    pub accept_key_b32: String,
+    /// `Account::new(master, 0).token_for(pk_1)`, base32.
+    pub accept_token_for_pk1_b32: String,
+    pub rotation_cert: RotationCertVector,
+    pub accept_mac: AcceptMacVector,
+    pub envelope: EnvelopeVector,
+    pub hkdf_rfc5869_case1: HkdfVector,
+    pub hmac_rfc4231_case1: HmacVector,
+    /// `ed25519_to_x25519(pk_0)`, base32 — libsodium's pk_to_curve25519.
+    pub ed25519_to_x25519_pk0_b32: String,
+    pub rns_bind: RnsBindVector,
+}
+
+#[derive(Deserialize)]
+pub struct RotationCertVector {
+    pub username: String,
+    pub old_index: u32,
+    pub new_index: u32,
+    pub when: i64,
+    pub cert_hex: String,
+}
+
+#[derive(Deserialize)]
+pub struct AcceptMacVector {
+    /// The token is `token_for(pk_1)` over this message id, base32.
+    pub message_id_b32: String,
+    pub mac_hex: String,
+}
+
+#[derive(Deserialize)]
+pub struct EnvelopeVector {
+    pub sender_index: u32,
+    pub recipient_index: u32,
+    pub when: i64,
+    /// The fixed ephemeral scalar the reference client used, hex.
+    pub ephemeral_hex: String,
+    pub padded_b32: String,
+    pub unpadded_b32: String,
+    pub message_id_hex: String,
+    pub body: String,
+    pub sender_pk_b32: String,
+}
+
+#[derive(Deserialize)]
+pub struct HkdfVector {
+    pub ikm_hex: String,
+    pub salt_hex: String,
+    pub info_hex: String,
+    /// The first 32 bytes of the 42-byte OKM.
+    pub okm_hex_32: String,
+}
+
+#[derive(Deserialize)]
+pub struct HmacVector {
+    pub key_hex: String,
+    pub data: String,
+    pub mac_hex: String,
+}
+
+#[derive(Deserialize)]
+pub struct RnsBindVector {
+    pub destination_hex: String,
+    pub link_id_hex: String,
+    pub h_hex: String,
+    pub server_static_hex: String,
+}
+
+pub fn load() -> Vectors {
+    serde_json::from_str(include_str!("../vectors.json")).expect("vectors.json parses")
+}
+
+fn b32_at(map: &std::collections::BTreeMap<String, String>, n: u32) -> &str {
+    map.get(&n.to_string()).expect("vectors.json has the index")
+}
+
+impl Vectors {
+    pub fn master(&self) -> [u8; KEY_LEN] {
+        data_encoding::HEXLOWER
+            .decode(self.master_hex.as_bytes())
+            .expect("master_hex decodes")
+            .try_into()
+            .expect("master is 32 bytes")
+    }
+
+    pub fn seed_b32(&self, n: u32) -> &str {
+        b32_at(&self.identity_seeds_b32, n)
+    }
+
+    pub fn pk_b32(&self, n: u32) -> &str {
+        b32_at(&self.identity_pks_b32, n)
+    }
+
+    pub fn xpriv_b32(&self, n: u32) -> &str {
+        b32_at(&self.identity_xprivs_b32, n)
+    }
+
+    pub fn hex(&self, hex: &str) -> Vec<u8> {
+        data_encoding::HEXLOWER.decode(hex.as_bytes()).expect("hex decodes")
+    }
+}