Merge branch 'main' into pg/diagnosis-report-submit

Author: pgherveou

docs/rfcs/payment-topup-sr25519.md

@@ -0,0 +1,40 @@
+---
+title: "Use Sr25519 Secret Keys in PaymentTopUpSource"
+owner: "@filippovecchiato"
+---
+
+# RFC — Use Sr25519 Secret Keys in PaymentTopUpSource
+
+## Summary
+
+Change all secret key fields in `PaymentTopUpSource` (RFC 0006) from 32-byte keys to 64-byte Sr25519 secret keys. The `PrivateKey` variant switches from `Ed25519PrivateKey` to `Sr25519SecretKey`, and the `Coins` variant widens its keys to match.
+
+## Motivation
+
+RFC 0006 specified Ed25519 for the `PrivateKey` variant, but the host implementation in triangle-js-sdks uses Sr25519 ([triangle-js-sdks#198](https://github.com/paritytech/triangle-js-sdks/pull/198)). The original RFC was simply wrong at that place — the accounts backing top-ups are Sr25519, not Ed25519. The `Coins` variant already used Sr25519, but with a 32-byte mini-secret; the upstream implementation uses the full 64-byte secret key for both.
+
+## Detailed Design
+
+`PaymentTopUpSource` changes from:
+
+```rust
+enum PaymentTopUpSource {
+    ProductAccount { derivation_index: u32 },
+    PrivateKey { ed25519_private_key: [u8; 32] },
+    Coins { sr25519_secret_keys: Vec<[u8; 32]> },
+}
+```
+
+to:
+
+```rust
+enum PaymentTopUpSource {
+    ProductAccount { derivation_index: u32 },
+    PrivateKey { sr25519_secret_key: [u8; 64] },
+    Coins { sr25519_secret_keys: Vec<[u8; 64]> },
+}
+```
+
+Both `PrivateKey` and `Coins` now carry 64-byte Sr25519 secret keys. The `Ed25519PrivateKey` type is removed.
+
+This is a **wire-breaking** change: the SCALE encoding of both variants changes length. All hosts and products must upgrade together within the same protocol version.

rust/crates/truapi/src/v01/payment.rs

@@ -39,14 +39,14 @@ pub enum PaymentTopUpSource {
     /// Fund from a one-time account represented by its private key. This is a
     /// standard account holding public funds, not a coin key.
     PrivateKey {
-        /// Ed25519 private key bytes.
-        ed25519_private_key: [u8; 32],
+        /// Sr25519 secret key bytes.
+        sr25519_secret_key: [u8; 64],
     },
     /// Fund directly from coin secret keys. Each key is an sr25519 secret
     /// controlling a single coin.
     Coins {
         /// Sr25519 secret keys, one per coin.
-        sr25519_secret_keys: Vec<[u8; 32]>,
+        sr25519_secret_keys: Vec<[u8; 64]>,
     },
 }