Amount now as coin string and u64

Cargo.toml

@@ -12,6 +12,7 @@ include_gif = "1.0.0"
 serde = {version="1.0.192", default_features = false, features = ["derive"]}
 serde-json-core = { git = "https://github.com/rust-embedded-community/serde-json-core"}
 hex = { version = "0.4.3", default-features = false, features = ["serde"] }
+numtoa = "0.2.4"
 
 [profile.release]
 opt-level = 'z'

src/app_ui/sign.rs

@@ -15,42 +15,60 @@
  * limitations under the License.
  *****************************************************************************/
 
+use core::str::from_utf8;
+
 use crate::handlers::sign_tx::Tx;
+use crate::utils::concatenate;
 use ledger_device_ui_sdk::bitmaps::{CROSSMARK, EYE, VALIDATE_14};
 use ledger_device_ui_sdk::ui::{Field, MultiFieldReview};
+use numtoa::NumToA;
+
+const MAX_COIN_LENGTH: usize = 10;
 
 pub fn ui_display_tx(tx: &Tx) -> bool {
- // Generate destination address string in hexadecimal format.
- let mut to_str = [0u8; 42];
- to_str[..2].copy_from_slice("0x".as_bytes());
- hex::encode_to_slice(tx.to, &mut to_str[2..]).unwrap();
-
- // Define transaction review fields
- let my_fields = [
- Field {
- name: "Amount",
- value: tx.value,
- },
- Field {
- name: "Destination",
- value: core::str::from_utf8(&to_str).unwrap(),
- },
- Field {
- name: "Memo",
- value: tx.memo,
- },
- ];
-
- // Create transaction review
- let my_review = MultiFieldReview::new(
- &my_fields,
- &["Review ", "Transaction"],
- Some(&EYE),
- "Approve",
- Some(&VALIDATE_14),
- "Reject",
- Some(&CROSSMARK),
- );
-
- my_review.show()
+ // Generate string for amount
+ let mut numtoa_buf = [0u8; 20];
+ let mut value_buf = [0u8; 20 + MAX_COIN_LENGTH + 1];
+
+ if let Ok(value_str) = concatenate(
+ &[tx.coin, &" ", tx.value.numtoa_str(10, &mut numtoa_buf)],
+ &mut value_buf,
+ ) {
+ // Generate destination address string in hexadecimal format.
+ let mut to_str = [0u8; 42];
+ to_str[..2].copy_from_slice("0x".as_bytes());
+ hex::encode_to_slice(tx.to, &mut to_str[2..]).unwrap();
+
+ // Define transaction review fields
+ let my_fields = [
+ Field {
+ name: "Amount",
+ value: value_str,
+ },
+ Field {
+ name: "Destination",
+ value: core::str::from_utf8(&to_str).unwrap(),
+ },
+ Field {
+ name: "Memo",
+ value: tx.memo,
+ },
+ ];
+
+ // Create transaction review
+ let my_review = MultiFieldReview::new(
+ &my_fields,
+ &["Review ", "Transaction"],
+ Some(&EYE),
+ "Approve",
+ Some(&VALIDATE_14),
+ "Reject",
+ Some(&CROSSMARK),
+ );
+
+ my_review.show()
+ } else {
+ // Coin name too long, concatenation buffer was too small.
+ return false;
+ }
 }

src/handlers/sign_tx.rs

@@ -31,8 +31,9 @@ const MAX_TRANSACTION_LEN: usize = 510;
 #[derive(Deserialize)]
 pub struct Tx<'a> {
  nonce: u64,
- pub value: &'a str,
- #[serde(with = "hex::serde")]
+ pub coin: &'a str,
+ pub value: u64,
+ #[serde(with = "hex::serde")] // Allows JSON deserialization from hex string
  pub to: [u8; 20],
  pub memo: &'a str,
 }

src/utils.rs

@@ -1,5 +1,5 @@
 use crate::AppSW;
-use core::char;
+use core::{char, str::from_utf8};
 
 pub const MAX_ALLOWED_PATH_LEN: usize = 10;
 const MAX_HEX_LEN: usize = 64;
@@ -31,20 +31,19 @@ pub fn read_bip32_path(data: &[u8], path: &mut [u32]) -> Result<usize, AppSW> {
  Ok(idx)
 }
 
-/// Concatenate multiple strings into a fixed-size array
-pub fn concatenate(strings: &[&str], output: &mut [u8]) {
+/// Returns concatenated strings, or an error if the concatenation buffer is too small.
+pub fn concatenate<'a>(strings: &[&str], output: &'a mut [u8]) -> Result<&'a str, ()> {
  let mut offset = 0;
 
  for s in strings {
  let s_len = s.len();
- let copy_len = core::cmp::min(s_len, output.len() - offset);
-
- if copy_len > 0 {
- output[offset..offset + copy_len].copy_from_slice(&s.as_bytes()[..copy_len]);
- offset += copy_len;
- } else {
- // If the output buffer is full, stop concatenating.
- break;
+ if offset + s_len > output.len() {
+ return Err(());
  }
+
+ output[offset..offset + s_len].copy_from_slice(&s.as_bytes());
+ offset += s_len;
  }
+
+ Ok(from_utf8(&output[..offset]).unwrap())
 }

tests/application_client/boilerplate_transaction.py

@@ -11,12 +11,14 @@ class TransactionError(Exception):
 class Transaction:
  def __init__(self,
  nonce: int,
- value: float,
+ coin: str,
+ value: int,
  to: str,
  memo: str,
  do_check: bool = True) -> None:
  self.nonce: int = nonce
- self.value: str = "CRAB " + str(value)
+ self.coin: str = coin
+ self.value: str = value
  self.to: str = to 
  self.memo: str = memo
 
@@ -31,6 +33,7 @@ def serialize(self) -> bytes:
  # Serialize the transaction data to a JSON-formatted string
  return json.dumps({
  "nonce": self.nonce,
+ "coin": self.coin,
  "value": self.value,
  "to": self.to,
  "memo": self.memo

tests/test_sign_cmd.py

@@ -26,7 +26,8 @@ def test_sign_tx_short_tx(firmware, backend, navigator, test_name):
  # Create the transaction that will be sent to the device for signing
  transaction = Transaction(
  nonce=1,
- value=0.777,
+ coin="CRAB",
+ value=777,
  to="de0b295669a9fd93d5f28d9ec85e40f4cb697bae",
  memo="For u EthDev"
  ).serialize()
@@ -70,8 +71,9 @@ def test_sign_tx_long_tx(firmware, backend, navigator, test_name):
 
  transaction = Transaction(
  nonce=1,
- to="de0b295669a9fd93d5f28d9ec85e40f4cb697bae",
+ coin="CRAB",
  value=666,
+ to="de0b295669a9fd93d5f28d9ec85e40f4cb697bae",
  memo=("This is a very long memo. "
  "It will force the app client to send the serialized transaction to be sent in chunk. "
  "As the maximum chunk size is 255 bytes we will make this memo greater than 255 characters. "
@@ -109,8 +111,9 @@ def test_sign_tx_refused(firmware, backend, navigator, test_name):
 
  transaction = Transaction(
  nonce=1,
- to="de0b295669a9fd93d5f28d9ec85e40f4cb697bae",
+ coin="CRAB",
  value=666,
+ to="de0b295669a9fd93d5f28d9ec85e40f4cb697bae",
  memo="This transaction will be refused by the user"
  ).serialize()