From e52a671810cc2b64eb6769311ff8bbb6264ad3df Mon Sep 17 00:00:00 2001
From: Julien Cretin <cretin@google.com>
Date: Tue, 3 Mar 2020 23:47:32 +0100
Subject: [PATCH] Support storing in RAM instead of flash
This permits to run without persistent storage. The benefit is that the board
doesn't implement a the syscall API in Tock. The disadvantage is that rebooting
the key will reset the storage.
---
.github/workflows/cargo_check.yml | 6 ++++++
Cargo.toml | 1 +
deploy.py | 8 ++++++++
run_desktop_tests.sh | 1 +
src/ctap/storage.rs | 21 ++++++++++++++-------
src/embedded_flash/buffer.rs | 3 ++-
src/embedded_flash/mod.rs | 2 --
7 files changed, 32 insertions(+), 10 deletions(-)
diff --git a/.github/workflows/cargo_check.yml b/.github/workflows/cargo_check.yml
index 60b96d1..a6c4c46 100644
--- a/.github/workflows/cargo_check.yml
+++ b/.github/workflows/cargo_check.yml
@@ -58,6 +58,12 @@ jobs:
command: check
args: --target thumbv7em-none-eabi --release --features debug_allocations
+ - name: Check OpenSK ram_storage
+ uses: actions-rs/cargo@v1
+ with:
+ command: check
+ args: --target thumbv7em-none-eabi --release --features ram_storage
+
- name: Check OpenSK debug_ctap,with_ctap1
uses: actions-rs/cargo@v1
with:
diff --git a/Cargo.toml b/Cargo.toml
index 03dc034..3155106 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -23,6 +23,7 @@ debug_ctap = ["crypto/derive_debug"]
with_ctap1 = ["crypto/with_ctap1"]
panic_console = ["libtock/panic_console"]
debug_allocations = ["libtock/debug_allocations"]
+ram_storage = []
[dev-dependencies]
elf2tab = "0.4.0"
diff --git a/deploy.py b/deploy.py
index ee7f54f..dc69c24 100755
--- a/deploy.py
+++ b/deploy.py
@@ -405,6 +405,14 @@ if __name__ == "__main__":
"(i.e. more debug messages will be sent over the console port "
"such as hexdumps of packets)."),
)
+ app_commands.add_argument(
+ "--no-persistent-storage",
+ action="append_const",
+ const="ram_storage",
+ dest="features",
+ help=("Compiles and installs the OpenSK application without persistent "
+ "storage (i.e. unplugging the key will reset the key)."),
+ )
apps_group = app_commands.add_mutually_exclusive_group()
apps_group.add_argument(
"--opensk",
diff --git a/run_desktop_tests.sh b/run_desktop_tests.sh
index e3f2b1e..b8e8896 100755
--- a/run_desktop_tests.sh
+++ b/run_desktop_tests.sh
@@ -30,6 +30,7 @@ cargo check --release --target=thumbv7em-none-eabi --features with_ctap1
cargo check --release --target=thumbv7em-none-eabi --features debug_ctap
cargo check --release --target=thumbv7em-none-eabi --features panic_console
cargo check --release --target=thumbv7em-none-eabi --features debug_allocations
+cargo check --release --target=thumbv7em-none-eabi --features ram_storage
cargo check --release --target=thumbv7em-none-eabi --features debug_ctap,with_ctap1
cargo check --release --target=thumbv7em-none-eabi --features debug_ctap,with_ctap1,panic_console,debug_allocations
diff --git a/src/ctap/storage.rs b/src/ctap/storage.rs
index e693a13..7569c1b 100644
--- a/src/ctap/storage.rs
+++ b/src/ctap/storage.rs
@@ -21,9 +21,9 @@ use alloc::vec::Vec;
use core::convert::TryInto;
use ctap2::embedded_flash::{self, StoreConfig, StoreEntry, StoreError, StoreIndex};
-#[cfg(test)]
+#[cfg(any(test, feature = "ram_storage"))]
type Storage = embedded_flash::BufferStorage;
-#[cfg(not(test))]
+#[cfg(not(any(test, feature = "ram_storage")))]
type Storage = embedded_flash::SyscallStorage;
// Those constants may be modified before compilation to tune the behavior of the key.
@@ -44,6 +44,9 @@ type Storage = embedded_flash::SyscallStorage;
// We have: I = ((P - 1) * 4092 - K * S) / 12 * C
//
// With P=20 and K=150, we have I > 2M which is enough for 500 increments per day for 10 years.
+#[cfg(feature = "ram_storage")]
+const NUM_PAGES: usize = 2;
+#[cfg(not(feature = "ram_storage"))]
const NUM_PAGES: usize = 20;
const MAX_SUPPORTED_RESIDENTIAL_KEYS: usize = 150;
@@ -130,10 +133,14 @@ pub struct PersistentStore {
store: embedded_flash::Store<Storage, Config>,
}
+#[cfg(feature = "ram_storage")]
+const PAGE_SIZE: usize = 0x100;
+#[cfg(not(feature = "ram_storage"))]
const PAGE_SIZE: usize = 0x1000;
+
const STORE_SIZE: usize = NUM_PAGES * PAGE_SIZE;
-#[cfg(not(test))]
+#[cfg(not(any(test, feature = "ram_storage")))]
#[link_section = ".app_state"]
static STORE: [u8; STORE_SIZE] = [0xff; STORE_SIZE];
@@ -144,9 +151,9 @@ impl PersistentStore {
///
/// This should be at most one instance of persistent store per program lifetime.
pub fn new(rng: &mut impl Rng256) -> PersistentStore {
- #[cfg(not(test))]
+ #[cfg(not(any(test, feature = "ram_storage")))]
let storage = PersistentStore::new_prod_storage();
- #[cfg(test)]
+ #[cfg(any(test, feature = "ram_storage"))]
let storage = PersistentStore::new_test_storage();
let mut store = PersistentStore {
store: embedded_flash::Store::new(storage, Config).unwrap(),
@@ -155,7 +162,7 @@ impl PersistentStore {
store
}
- #[cfg(not(test))]
+ #[cfg(not(any(test, feature = "ram_storage")))]
fn new_prod_storage() -> Storage {
let store = unsafe {
// Safety: The store cannot alias because this function is called only once.
@@ -167,7 +174,7 @@ impl PersistentStore {
}
}
- #[cfg(test)]
+ #[cfg(any(test, feature = "ram_storage"))]
fn new_test_storage() -> Storage {
let store = vec![0xff; STORE_SIZE].into_boxed_slice();
let options = embedded_flash::BufferOptions {
diff --git a/src/embedded_flash/buffer.rs b/src/embedded_flash/buffer.rs
index b7cf3f1..4fcd80f 100644
--- a/src/embedded_flash/buffer.rs
+++ b/src/embedded_flash/buffer.rs
@@ -13,6 +13,7 @@
// limitations under the License.
use super::{Index, Storage, StorageError, StorageResult};
+use alloc::boxed::Box;
pub struct BufferStorage {
storage: Box<[u8]>,
@@ -230,7 +231,7 @@ impl Snapshot {
fn get(&mut self) -> Result<Box<[u8]>, usize> {
let mut snapshot = Snapshot::Ready;
- std::mem::swap(self, &mut snapshot);
+ core::mem::swap(self, &mut snapshot);
match snapshot {
Snapshot::Armed { delay } => Err(delay),
Snapshot::Taken { storage } => Ok(storage),
diff --git a/src/embedded_flash/mod.rs b/src/embedded_flash/mod.rs
index 5e54059..8551a52 100644
--- a/src/embedded_flash/mod.rs
+++ b/src/embedded_flash/mod.rs
@@ -12,13 +12,11 @@
// See the License for the specific language governing permissions and
// limitations under the License.
-#[cfg(feature = "std")]
mod buffer;
mod storage;
mod store;
mod syscall;
-#[cfg(feature = "std")]
pub use self::buffer::{BufferOptions, BufferStorage};
pub use self::storage::{Index, Storage, StorageError, StorageResult};
pub use self::store::{Store, StoreConfig, StoreEntry, StoreError, StoreIndex};
--
GitLab