feat!: encrypted logs refactor

boxes/boxes/react/src/contracts/src/main.nr

@@ -6,7 +6,7 @@ contract BoxReact {
         protocol_types::public_keys::OvpkM,
         keys::getters::get_public_keys,
         prelude::{AztecAddress, PrivateMutable, Map, NoteInterface, NoteHeader, Point},
-        encrypted_logs::encrypted_note_emission::encode_and_encrypt_note,
+        encrypted_logs::log_assembly_strategies::default_aes128::note::encode_and_encrypt_note,
         macros::{storage::storage, functions::{private, public, initializer}}
     };
     use dep::value_note::value_note::ValueNote;

boxes/boxes/vanilla/src/contracts/src/main.nr

@@ -6,7 +6,7 @@ contract Vanilla {
         protocol_types::public_keys::OvpkM,
         keys::getters::get_public_keys,
         prelude::{AztecAddress, PrivateMutable, Map, NoteInterface, NoteHeader, Point},
-        encrypted_logs::encrypted_note_emission::encode_and_encrypt_note,
+        encrypted_logs::log_assembly_strategies::default_aes128::note::encode_and_encrypt_note,
         macros::{storage::storage, functions::{private, public, initializer}}
     };
     use dep::value_note::value_note::{ValueNote, VALUE_NOTE_LEN};

boxes/boxes/vite/src/contracts/src/main.nr

@@ -3,7 +3,7 @@ use dep::aztec::macros::aztec;
 #[aztec]
 contract BoxReact {
     use dep::aztec::{
-        encrypted_logs::encrypted_note_emission::encode_and_encrypt_note,
+        encrypted_logs::log_assembly_strategies::default_aes128::note::encode_and_encrypt_note,
         macros::{functions::{initializer, private}, storage::storage},
         prelude::{AztecAddress, Map, PrivateMutable},
     };

cspell.json

@@ -89,6 +89,7 @@
     "dockerized",
     "doesnt",
     "dont",
+    "ecdh",
     "elif",
     "enrs",
     "entrypoints",
@@ -281,6 +282,7 @@
     "unexcluded",
     "unfinalised",
     "unnullify",
+    "unpadded",
     "unprefixed",
     "unshift",
     "unshifted",

docs/docs/migration_notes.md

@@ -31,6 +31,19 @@ impl Packable<U128_PACKED_LEN> for U128 {
 }
 ```
 
+### Logs for notes, partial notes, and events have been refactored.
+
+We're preparing to make log assembly more customisable. These paths have changed.
+```diff
+- use dep::aztec::encrypted_logs::encrypted_note_emission::encode_and_encrypt_note,
++ use dep::aztec::encrypted_logs::log_assembly_strategies::default_aes128::note::encode_and_encrypt_note,
+```
+
+And similar paths for `encode_and_encrypt_note_unconstrained`, and for events and partial notes.
+
+The way in which logs are assembled in this "default_aes128" strategy is has also changed. I repeat: **Encrypted log layouts have changed**. The corresponding typescript for note discovery has also been changed, but if you've rolled your own functions for parsing and decrypting logs, those will be broken by this change.
+
+
 ## 0.72.0
 ### Some functions in `aztec.js` and `@aztec/accounts` are now async
 In our efforts to make libraries more browser-friendly and providing with more bundling options for `bb.js` (like a non top-level-await version), some functions are being made async, in particular those that access our cryptographic functions.

noir-projects/aztec-nr/aztec/src/encrypted_logs/encrypt/aes128.nr

@@ -0,0 +1,76 @@
+use std::hash::{from_field_unsafe as fr_to_fq_unsafe, sha256};
+
+use dep::protocol_types::{
+    constants::{GENERATOR_INDEX__SYMMETRIC_KEY, GENERATOR_INDEX__SYMMETRIC_KEY_2},
+    hash::poseidon2_hash_with_separator,
+    point::Point,
+};
+
+use crate::utils::point::point_to_bytes;
+
+fn extract_close_to_uniformly_random_256_bits_from_ecdh_shared_secret_using_poseidon2(
+    shared_secret: Point,
+) -> [u8; 32] {
+    let rand1: Field = poseidon2_hash_with_separator(
+        [shared_secret.x, shared_secret.y],
+        GENERATOR_INDEX__SYMMETRIC_KEY,
+    );
+    let rand2: Field = poseidon2_hash_with_separator(
+        [shared_secret.x, shared_secret.y],
+        GENERATOR_INDEX__SYMMETRIC_KEY_2,
+    );
+    let rand1_bytes: [u8; 16] = rand1.to_le_bytes();
+    let rand2_bytes: [u8; 16] = rand2.to_le_bytes();
+    let mut bytes: [u8; 32] = [0; 32];
+    for i in 0..16 {
+        bytes[i] = rand1_bytes[i];
+        bytes[i + 1] = rand2_bytes[i];
+    }
+    bytes
+}
+
+fn extract_close_to_uniformly_random_256_bits_from_ecdh_shared_secret_using_sha256(
+    shared_secret: Point,
+) -> [u8; 32] {
+    let shared_secret_bytes: [u8; 32] = point_to_bytes(shared_secret);
+
+    let mut shared_secret_bytes_with_separator: [u8; 33] = std::mem::zeroed();
+    for i in 0..shared_secret_bytes.len() {
+        shared_secret_bytes_with_separator[i] = shared_secret_bytes[i];
+    }
+    shared_secret_bytes_with_separator[32] = GENERATOR_INDEX__SYMMETRIC_KEY;
+
+    sha256(shared_secret_bytes_with_separator)
+}
+
+fn derive_aes_symmetric_key_and_iv_from_ecdh_shared_secret(
+    shared_secret: Point,
+    randomness_extraction_fn: fn(Point) -> [u8; 32],
+) -> ([u8; 16], [u8; 16]) {
+    let random_256_bits = randomness_extraction_fn(shared_secret);
+    let mut sym_key = [0; 16];
+    let mut iv = [0; 16];
+    for i in 0..16 {
+        sym_key[i] = random_256_bits[i];
+        iv[i] = random_256_bits[i + 16];
+    }
+    (sym_key, iv)
+}
+
+pub fn derive_aes_symmetric_key_and_iv_from_ecdh_shared_secret_using_sha256(
+    shared_secret: Point,
+) -> ([u8; 16], [u8; 16]) {
+    derive_aes_symmetric_key_and_iv_from_ecdh_shared_secret(
+        shared_secret,
+        extract_close_to_uniformly_random_256_bits_from_ecdh_shared_secret_using_sha256,
+    )
+}
+
+pub fn derive_aes_symmetric_key_and_iv_from_ecdh_shared_secret_using_poseidon2(
+    shared_secret: Point,
+) -> ([u8; 16], [u8; 16]) {
+    derive_aes_symmetric_key_and_iv_from_ecdh_shared_secret(
+        shared_secret,
+        extract_close_to_uniformly_random_256_bits_from_ecdh_shared_secret_using_poseidon2,
+    )
+}

noir-projects/aztec-nr/aztec/src/encrypted_logs/encrypt/mod.nr

@@ -0,0 +1 @@
+pub mod aes128;