Simulate securechip stretching as well
What the developer wrote
Authored by Niklas Dusenlund
Simulate securechip stretching as well
What changed, and why it matters
This commit only changes the graphical simulator used for testing the BitBox02 firmware. It adds a one-second artificial delay to the simulated secure chip's key-stretching function so that developers can visually test the unlock animation. It does not affect the real hardware firmware or any user-facing security behavior.
No security action required. This is a benign simulator-only change.
Security signals we found
No strong security signals were identified.
Evidence from the diff
The patch introduces a simulator-graphical feature flag in bitbox-platform-host and, when that flag is enabled (and testing is not), inserts an awaited 1000 ms delay inside the host-side FakeSecureChip::stretch implementation. The graphical simulator crates are updated to enable this feature. This is purely a test/UX simulation change; the real secure-chip stretching path on device is untouched.
Changed components
src/rust/bitbox-platform-host/src/securechip.rssrc/rust/bitbox-platform-host/Cargo.tomlsrc/rust/bitbox02-rust/Cargo.tomltest/simulator-graphical-bb03/Cargo.tomltest/simulator-graphical/Cargo.tomlInspect captured patch +14 / −2
diff --git a/src/rust/bitbox-platform-host/Cargo.toml b/src/rust/bitbox-platform-host/Cargo.toml
index 56b48ea..991e52d 100644
--- a/src/rust/bitbox-platform-host/Cargo.toml
+++ b/src/rust/bitbox-platform-host/Cargo.toml
@@ -15,6 +15,8 @@ zeroize = { workspace = true }
[features]
app-u2f = ["bitbox-hal/app-u2f"]
+simulator-graphical = []
+testing = []
[dev-dependencies]
async_test = { path = "../async_test" }
diff --git a/src/rust/bitbox-platform-host/src/securechip.rs b/src/rust/bitbox-platform-host/src/securechip.rs
index a785d25..aa6321f 100644
--- a/src/rust/bitbox-platform-host/src/securechip.rs
+++ b/src/rust/bitbox-platform-host/src/securechip.rs
@@ -3,6 +3,9 @@
use alloc::collections::VecDeque;
use alloc::{boxed::Box, vec::Vec};
+#[cfg(all(feature = "simulator-graphical", not(feature = "testing")))]
+use bitbox_hal::Timer;
+
use bitcoin::hashes::Hash;
use hex_lit::hex;
@@ -128,6 +131,12 @@ impl bitbox_hal::SecureChip for FakeSecureChip {
));
engine.input(msg);
let hmac_result: Hmac<sha256::Hash> = Hmac::from_engine(engine);
+
+ // Keep KDF completion visibly delayed on the host so unlock animation start/play can be
+ // manually tested in the graphical simulators.
+ #[cfg(all(feature = "simulator-graphical", not(feature = "testing")))]
+ crate::timer::HostTimer::delay_for(core::time::Duration::from_millis(1000)).await;
+
Ok(Box::new(zeroize::Zeroizing::new(
hmac_result.to_byte_array(),
)))
diff --git a/src/rust/bitbox02-rust/Cargo.toml b/src/rust/bitbox02-rust/Cargo.toml
index 81208f7..757c54f 100644
--- a/src/rust/bitbox02-rust/Cargo.toml
+++ b/src/rust/bitbox02-rust/Cargo.toml
@@ -100,6 +100,7 @@ app-cardano = [
testing = [
"dep:bitbox-platform-host",
+ "bitbox-platform-host?/testing",
"bitbox02/testing",
"bitbox-secp256k1/testing",
"util/testing"
diff --git a/test/simulator-graphical-bb03/Cargo.toml b/test/simulator-graphical-bb03/Cargo.toml
index a48bc18..f34f62a 100644
--- a/test/simulator-graphical-bb03/Cargo.toml
+++ b/test/simulator-graphical-bb03/Cargo.toml
@@ -5,7 +5,7 @@ edition = "2024"
[dependencies]
bitbox-hal = { path = "../../src/rust/bitbox-hal" }
-bitbox-platform-host = { path = "../../src/rust/bitbox-platform-host" }
+bitbox-platform-host = { path = "../../src/rust/bitbox-platform-host", features = ["simulator-graphical"] }
bitbox-usb-report-queue = { path = "../../src/rust/bitbox-usb-report-queue" }
bitbox02-rust = { path = "../../src/rust/bitbox02-rust", features = ["simulator-graphical"] }
bitbox-aes = { path = "../../src/rust/bitbox-aes" }
diff --git a/test/simulator-graphical/Cargo.toml b/test/simulator-graphical/Cargo.toml
index d5effad..ea81ec8 100644
--- a/test/simulator-graphical/Cargo.toml
+++ b/test/simulator-graphical/Cargo.toml
@@ -7,7 +7,7 @@ edition = "2024"
bitbox02-rust = { path="../../src/rust/bitbox02-rust", features=["simulator-graphical"] }
bitbox02-rust-c = { path="../../src/rust/bitbox02-rust-c", features=["simulator-graphical"] }
bitbox02 = { path="../../src/rust/bitbox02", features=["simulator-graphical"] }
-bitbox-platform-host = { path = "../../src/rust/bitbox-platform-host" }
+bitbox-platform-host = { path = "../../src/rust/bitbox-platform-host", features = ["simulator-graphical"] }
bitbox-aes = { path="../../src/rust/bitbox-aes"}
winit = "0.30.12"
tracing = {version = "0.1.41", features=["log"]}
Why this scored 15/100
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