Add error codes

README.md

@@ -1,60 +1,152 @@
 # Ledger Bitcoin Application
 
-## Prerequisite
+This is the Bitcoin application for Ledger Nano X/SP, Stax and Flex.
 
-Be sure to have your environment correctly set up (see [Getting Started](https://developers.ledger.com/docs/nano-app/introduction/)) and [ledgerblue](https://pypi.org/project/ledgerblue/) installed.
+## Quick start guide
 
-If you want to benefit from [vscode](https://code.visualstudio.com/) integration, it's recommended to move the toolchain in `/opt` and set `BOLOS_ENV` environment variable as follows
+### With VSCode
 
+You can quickly setup a convenient environment to build and test your application by using [Ledger's VSCode developer tools extension](https://marketplace.visualstudio.com/items?itemName=LedgerHQ.ledger-dev-tools) which leverages the [ledger-app-dev-tools](https://github.com/LedgerHQ/ledger-app-builder/pkgs/container/ledger-app-builder%2Fledger-app-dev-tools) docker image.
+
+It will allow you, whether you are developing on macOS, Windows or Linux to quickly **build** your apps, **test** them on **Speculos** and **load** them on any supported device.
+
+* Install and run [Docker](https://www.docker.com/products/docker-desktop/).
+* Make sure you have an X11 server running :
+    * On Ubuntu Linux, it should be running by default.
+    * On macOS, install and launch [XQuartz](https://www.xquartz.org/) (make sure to go to XQuartz > Preferences > Security and check "Allow client connections").
+    * On Windows, install and launch [VcXsrv](https://sourceforge.net/projects/vcxsrv/) (make sure to configure it to disable access control).
+* Install [VScode](https://code.visualstudio.com/download) and add [Ledger's extension](https://marketplace.visualstudio.com/items?itemName=LedgerHQ.ledger-dev-tools).
+* Open a terminal and clone `app-bitcoin-new` with `git clone git@github.com:LedgerHQ/app-bitcoin-new.git`.
+* Open the `app-bitcoin-new` folder with VSCode.
+* Use Ledger extension's sidebar menu or open the tasks menu with `ctrl + shift + b` (`command + shift + b` on a Mac) to conveniently execute actions :
+    * Build the app for the device model of your choice with `Build`.
+    * Test your binary on [Speculos](https://github.com/LedgerHQ/speculos) with `Run with Speculos`.
+    * You can also run functional tests, load the app on a physical device, and more.
+
+:information_source: The terminal tab of VSCode will show you what commands the extension runs behind the scene.
+
+### With a terminal
+
+The [ledger-app-dev-tools](https://github.com/LedgerHQ/ledger-app-builder/pkgs/container/ledger-app-builder%2Fledger-app-dev-tools) docker image contains all the required tools and libraries to **build**, **test** and **load** an application.
+
+You can download it from the ghcr.io docker repository:
+
+```shell
+sudo docker pull ghcr.io/ledgerhq/ledger-app-builder/ledger-app-dev-tools:latest
 ```
-BOLOS_ENV=/opt/bolos-devenv
-```
 
-and do the same with `BOLOS_SDK` environment variable
+You can then enter this development environment by executing the following command from the directory of the application `git` repository:
+
+**Linux (Ubuntu)**
 
+```shell
+sudo docker run --rm -ti --user "$(id -u):$(id -g)" --privileged -v "/dev/bus/usb:/dev/bus/usb" -v "$(realpath .):/app" ghcr.io/ledgerhq/ledger-app-builder/ledger-app-dev-tools:latest
 ```
-BOLOS_SDK=/opt/nanos-secure-sdk
+
+**macOS**
+
+```shell
+sudo docker run  --rm -ti --user "$(id -u):$(id -g)" --privileged -v "$(pwd -P):/app" ghcr.io/ledgerhq/ledger-app-builder/ledger-app-dev-tools:latest
 ```
 
-## Compilation
+**Windows (with PowerShell)**
 
+```shell
+docker run --rm -ti --privileged -v "$(Get-Location):/app" ghcr.io/ledgerhq/ledger-app-builder/ledger-app-dev-tools:latest
 ```
+
+The application's code will be available from inside the docker container, you can proceed to the following compilation steps to build your app.
+
+## Compilation and load
+
+To easily setup a development environment for compilation and loading on a physical device, you can use the [VSCode integration](#with-vscode) whether you are on Linux, macOS or Windows.
+
+If you prefer using a terminal to perform the steps manually, you can use the guide below.
+
+### Compilation
+
+Setup a compilation environment by following the [shell with docker approach](#with-a-terminal).
+
+From inside the container, use the following command to build the app :
+
+```shell
 make DEBUG=1  # compile optionally with PRINTF
-make load     # load the app on the Nano using ledgerblue
 ```
 
-## Documentation
+You can choose which device to compile and load for by setting the `BOLOS_SDK` environment variable to the following values :
+
+* `BOLOS_SDK=$NANOX_SDK`
+* `BOLOS_SDK=$NANOSP_SDK`
+* `BOLOS_SDK=$STAX_SDK`
+
+By default this variable is set to build/load for Nano S+.
+
+The app is compiled for testnet by default. In order to compile the app for mainnet, add `COIN=bitcoin` when running the `make` command.
+
+### Loading on a physical device
+
+This step will vary slightly depending on your platform.
+
+:information_source: Your physical device must be connected, unlocked and the screen showing the dashboard (not inside an application).
+
+**Linux (Ubuntu)**
 
-High level documentation on the architecture and interface of the app:
-- [bitcoin.md](doc/bitcoin.md): specifications of application commands.
-- [wallet.md](doc/wallet.md): supported wallet signing policies.
-- [merkle.md](doc/merkle.md): rationale and specifications for the usage of Merkle trees.
+First make sure you have the proper udev rules added on your host :
 
-Additional documentation can be generated with [doxygen](https://www.doxygen.nl)
+```shell
+# Run these commands on your host, from the app's source folder.
+sudo cp .vscode/20-ledger.ledgerblue.rules /etc/udev/rules.d/
+sudo udevadm control --reload-rules 
+sudo udevadm trigger
+```
+
+Then once you have [opened a terminal](#with-a-terminal) in the `app-builder` image and [built the app](#compilation-and-load) for the device you want, run the following command :
 
+```shell
+# Run this command from the app-builder container terminal.
+make load    # load the app on a Nano S+ by default
 ```
-doxygen .doxygen/Doxyfile
+
+[Setting the BOLOS_SDK environment variable](#compilation-and-load) will allow you to load on whichever supported device you want.
+
+**macOS / Windows (with PowerShell)**
+
+:information_source: It is assumed you have [Python](https://www.python.org/downloads/) installed on your computer.
+
+Run these commands on your host from the app's source folder once you have [built the app](#compilation-and-load) for the device you want :
+
+```shell
+# Install Python virtualenv
+python3 -m pip install virtualenv 
+# Create the 'ledger' virtualenv
+python3 -m virtualenv ledger
 ```
 
-the process outputs HTML and LaTeX documentations in `doc/html` and `doc/latex` folders.
+Enter the Python virtual environment
 
-## Client libraries
+* macOS : `source ledger/bin/activate`
+* Windows : `.\ledger\Scripts\Activate.ps1`
 
-A [Python client library](bitcoin_client), a [TypeScript client library](bitcoin_client_js) and a [Rust client library](bitcoin_client_rs) are available in this repository.
+```shell
+# Install Ledgerblue (tool to load the app)
+python3 -m pip install ledgerblue 
+# Load the app.
+python3 -m ledgerblue.runScript --scp --fileName bin/app.apdu --elfFile bin/app.elf
+```
 
-## Tests & Continuous Integration
+## Documentation
 
-The flow processed in [GitHub Actions](https://github.com/features/actions) is the following:
+For many use cases, the code examples provided in the following client libraries might be sufficient to get started:
+- [Python client library](bitcoin_client)
+- [JavaScript client library](bitcoin_client_js)
+- [Rust client library](bitcoin_client_rs)
 
-- Code formatting with [clang-format](http://clang.llvm.org/docs/ClangFormat.html)
-- Compilation of the application for Ledger Nano S in [ledger-app-builder](https://github.com/LedgerHQ/ledger-app-builder)
-- Unit tests of C functions with [cmocka](https://cmocka.org/) (see [unit-tests/](unit-tests/))
-- End-to-end tests with [Speculos](https://github.com/LedgerHQ/speculos) emulator (see [tests/](tests/))
-- Code coverage with [gcov](https://gcc.gnu.org/onlinedocs/gcc/Gcov.html)/[lcov](http://ltp.sourceforge.net/coverage/lcov.php) and upload to [codecov.io](https://about.codecov.io)
-- Documentation generation with [doxygen](https://www.doxygen.nl)
+If you need to go deeper into the rabbit hole 🐇🕳️, refer to the following documents:
+- [bitcoin.md](doc/bitcoin.md): Low-level documentation of the Bitcoin app's communication protocol and commands.
+- [merkle.md](doc/merkle.md): Advanced details on techniques used in the Bitcoin app's secured and scalable communication protocol.
+- [wallet.md](doc/wallet.md): Information on the types of scripts supported by the Ledger Bitcoin app and the security requirements for multi-user or multi-key spending policies.
+- [debugging.md](doc/debugging.md): Guidance on how to diagnose and resolve issues.
 
-It outputs 4 artifacts:
+## Tests
 
-- `bitcoin-app-debug` within output files of the compilation process in debug mode
-- `code-coverage` within HTML details of code coverage
-- `documentation` within HTML auto-generated documentation
+See the [tests](tests) folder for documentation on the functional and end-to-end test suites of the bitcoin app, and the [unit-tests](unit-tests) folder for the C unit tests.

doc/bitcoin.md

@@ -8,7 +8,7 @@ The protocol documentation for version from 2.0.0 and before 2.1.0 is [here](./v
 
 ### APDUs
 
-The messaging format of the app is compatible with the [APDU protocol](https://developers.ledger.com/docs/nano-app/application-structure/#apdu-interpretation-loop). The `P1` field is reserved for future use and must be set to `0` in all messages. The `P2` field is used as a protocol version identifier; the current version is `1`, while version `0` is still supported. No other value must be used.
+The messaging format of the app is compatible with the [APDU protocol](https://developers.ledger.com/docs/device-app/explanation/io#apdu-interpretation-loop). The `P1` field is reserved for future use and must be set to `0` in all messages. The `P2` field is used as a protocol version identifier; the current version is `1`, while version `0` is still supported. No other value must be used.
 
 The main commands use `CLA = 0xE1`, unlike the legacy Bitcoin application that used `CLA = 0xE0`.
 

doc/debugging.md

@@ -0,0 +1,23 @@
+This page contains some information for developers on how to debug failures of the commands of the Ledger Bitcoin app.
+
+# Status Words
+
+Failures in the app's commands are always reported by a corresponding Status Word; see [bitcoin.md](bitcoin.md#status-words) for the currently defined Status Words. Client libraries generally return structured versions of the same Status Words.
+
+The Status Word is contained in the last 2 bytes of the APDU Response, interpreted as a big-endian 16-bit constant.
+
+# Error codes
+
+In addition to the Status Word, some errors provide further details as an _error code_, contained in the first two bytes of the _data_ portion of the reply.
+
+Integrations can ignore the error codes and should not rely on them in production (as they are not guaranteed to be consistent across versions of the app); however, they can provide valuable debugging information for developers working on an integration.
+
+You can see the list of the currently defined error codes in [error_codes.h](../src/error_codes.h).
+
+# Running on Speculos with semihosting
+
+When running the bitcoin app on the [speculos](https://github.com/LedgerHQ/speculos) emulator, additional debugging information can be printed on the command line (on the same terminal where speculos is running) by defining the `DEBUG=10` constant when running the `make` command. See the [ledger-app-builder](https://github.com/LedgerHQ/ledger-app-builder?tab=readme-ov-file#compile-your-app-in-the-container) for instructions on how to build the app for speculos.
+
+Binaries produced in this way _will_ crash if sideloading on a real device.
+
+Note: `DEBUG=10` is a feature of the Bitcoin app, and is not used in other Ledger apps.

doc/v0/bitcoin.md

@@ -6,7 +6,7 @@ This page described the _deprecated_ version 0 of the protocol, as implemented i
 
 ### APDUs
 
-The messaging format of the app is compatible with the [APDU protocol](https://developers.ledger.com/docs/nano-app/application-structure/#apdu-interpretation-loop). The `P1` and `P2` fields are reserved for future use and must be set to `0` in all messages.
+The messaging format of the app is compatible with the [APDU protocol](https://developers.ledger.com/docs/device-app/explanation/io#apdu-interpretation-loop). The `P1` and `P2` fields are reserved for future use and must be set to `0` in all messages.
 
 The main commands use `CLA = 0xE1`, unlike the legacy Bitcoin application that used `CLA = 0xE0`.
 

src/boilerplate/dispatcher.h

@@ -47,6 +47,15 @@ static inline void SEND_RESPONSE(struct dispatcher_context_s *dc,
     dc->send_response();
 }
 
+static inline void SEND_SW_EC(struct dispatcher_context_s *dc, uint16_t sw, uint16_t error_code) {
+    uint8_t error_code_buf[2];
+    error_code_buf[0] = (error_code >> 8) & 0xFF;
+    error_code_buf[1] = error_code & 0xFF;
+    dc->add_to_response(&error_code_buf, sizeof(error_code_buf));
+    dc->finalize_response(sw);
+    dc->send_response();
+}
+
 /**
  * Describes a command that can be processed by the dispatcher.
  */

src/error_codes.h

@@ -0,0 +1,110 @@
+#pragma once
+
+/**
+ * REGISTER_WALLET
+ */
+
+// The name of the policy is not acceptable
+#define EC_REGISTER_WALLET_UNACCEPTABLE_POLICY_NAME 0x0000
+
+// The wallet policy does not respect the requirement of BIP-388, or the sanity rules of miniscript
+#define EC_REGISTER_WALLET_POLICY_NOT_SANE 0x0001
+
+// No key in the wallet policy was recognized as internal.
+#define EC_REGISTER_WALLET_POLICY_HAS_NO_INTERNAL_KEY 0x0002
+
+/**
+ * SIGN_PSBT
+ */
+
+// The wallet policy is not standard; it must be registered first and the HMAC must be provided.
+#define EC_SIGN_PSBT_MISSING_HMAC_FOR_NONDEFAULT_POLICY 0x0000
+
+// For standard wallet policies, the name must be zero-length (empty).
+#define EC_SIGN_PSBT_NO_NAME_FOR_DEFAULT_POLICY 0x0001
+
+// No key in the wallet policy was recognized as internal.
+#define EC_SIGN_PSBT_WALLET_POLICY_HAS_NO_INTERNAL_KEY 0x0002
+
+// Depending on the transaction type, at least one of the non-witness UTXO or witness UTXO must be
+// present in the PSBT. Check in BIP-174 for the specific requirements for the transaction type.
+#define EC_SIGN_PSBT_MISSING_NONWITNESSUTXO_AND_WITNESSUTXO 0x0003
+
+// Failed to check the txid recomputed from the non-witness-utxo. Make sure that the
+// non-witness-utxo and the PSBT_IN_PREVIOUS_TXID fields are filled correctly.
+#define EC_SIGN_PSBT_NONWITNESSUTXO_CHECK_FAILED 0x0004
+
+// The scriptpubkey or the amount in the non-witness-utxo does not match the one in the
+// witness-utxo.
+#define EC_SIGN_PSBT_NONWITNESSUTXO_AND_WITNESSUTXO_MISMATCH 0x0005
+
+// Per BIP-174, legacy inputs must have the non-witness-utxo, but no witness-utxo.
+#define EC_SIGN_PSBT_MISSING_NONWITNESSUTXO_OR_UNEXPECTED_WITNESSUTXO_FOR_LEGACY 0x0006
+
+// Per BIP-174, all segwit (or taproot) inputs must have the witness-utxo field.
+#define EC_SIGN_PSBT_MISSING_WITNESSUTXO_FOR_SEGWIT 0x0007
+
+// If an input has SIGHASH_SINGLE, its index must be less than the number of outputs.
+#define EC_SIGN_PSBT_UNALLOWED_SIGHASH_SINGLE 0x0008
+
+// The number of change outputs is larger than the maximum that is allowed.
+#define EC_SIGN_PSBT_TOO_MANY_CHANGE_OUTPUTS 0x0009
+
+// The witness script in the PSBT is incorrect.
+#define EC_SIGN_PSBT_MISMATCHING_WITNESS_SCRIPT 0x000a
+
+// The redeem Script in the PSBT is incorrect.
+#define EC_SIGN_PSBT_MISMATCHING_REDEEM_SCRIPT 0x000b
+
+/**
+ * Swap
+ */
+
+// For swap error codes, the first byte is standardized across apps.
+// Refer to the documentation of app-exchange.
+
+// Internal application error, forward to the firmware team for analysis.
+#define EC_SWAP_ERROR_INTERNAL 0x0000
+
+// The amount does not match the one validated in Exchange.
+#define EC_SWAP_ERROR_WRONG_AMOUNT 0x0100
+
+// The destination address does not match the one validated in Exchange.
+#define EC_SWAP_ERROR_WRONG_DESTINATION 0x0200
+
+// The fees are different from what was validated in Exchange.
+#define EC_SWAP_ERROR_WRONG_FEES 0x0300
+
+// The method used is invalid in Exchange context.
+#define EC_SWAP_ERROR_WRONG_METHOD 0x0400
+// Only default wallet policies can be used in swaps.
+#define EC_SWAP_ERROR_WRONG_METHOD_NONDEFAULT_POLICY 0x0401
+// No external inputs allowed in swap transactions.
+#define EC_SWAP_ERROR_WRONG_METHOD_EXTERNAL_INPUTS 0x0402
+// Segwit transaction in swap must have the non-witness UTXO in the PSBT.
+#define EC_SWAP_ERROR_WRONG_METHOD_MISSING_NONWITNESSUTXO 0x0403
+// Standard swap transaction must have exactly 1 external output.
+#define EC_SWAP_ERROR_WRONG_METHOD_WRONG_N_OF_OUTPUTS 0x0404
+// Invalid or unsupported script for external output.
+#define EC_SWAP_ERROR_WRONG_METHOD_WRONG_UNSUPPORTED_OUTPUT 0x0405
+
+// The mode used for the cross-chain hash validation is not supported.
+#define EC_SWAP_ERROR_CROSSCHAIN_WRONG_MODE 0x0500
+
+// The method used is invalid in cross-chain Exchange context.
+#define EC_SWAP_ERROR_CROSSCHAIN_WRONG_METHOD 0x0600
+// The first output must be OP_RETURN <data> for a cross-chain swap.
+#define EC_SWAP_ERROR_CROSSCHAIN_WRONG_METHOD_INVALID_FIRST_OUTPUT 0x0601
+// OP_RETURN with non-zero value is not supported.
+#define EC_SWAP_ERROR_CROSSCHAIN_WRONG_METHOD_NONZERO_AMOUNT 0x0602
+
+// The hash for the cross-chain transaction does not match the validated value.
+#define EC_SWAP_ERROR_CROSSCHAIN_WRONG_HASH 0x0700
+
+// A generic or unspecified error not covered by the specific error codes above. Refer to the
+// remaining bytes for further details on the error.
+#define EC_SWAP_ERROR_GENERIC 0xFF00
+// Unknown swap mode.
+#define EC_SWAP_ERROR_GENERIC_UNKNOWN_MODE 0xFF01
+// handle_swap_sign_transaction.c::copy_transaction_parameters failed.
+#define EC_SWAP_ERROR_GENERIC_COPY_TRANSACTION_PARAMETERS_FAILED 0xFF02

src/handler/get_wallet_address.c

@@ -30,6 +30,7 @@
 #include "../commands.h"
 #include "../constants.h"
 #include "../crypto.h"
+#include "../error_codes.h"
 #include "../ui/display.h"
 #include "../ui/menu.h"
 
@@ -162,7 +163,7 @@ void handler_get_wallet_address(dispatcher_context_t *dc, uint8_t protocol_versi
     // Swap feature: check that the wallet policy is a default one
     if (G_swap_state.called_from_swap && !is_wallet_default) {
         PRINTF("Must be a default wallet policy for swap feature\n");
-        SEND_SW(dc, SW_FAIL_SWAP);
+        SEND_SW_EC(dc, SW_FAIL_SWAP, EC_SWAP_ERROR_WRONG_METHOD_NONDEFAULT_POLICY);
         finalize_exchange_sign_transaction(false);
     }
 

src/handler/lib/policy.c

@@ -889,7 +889,7 @@ __attribute__((warn_unused_result)) static int process_multi_a_sortedmulti_a_nod
 
     // bitvector of used keys (only relevant for sorting keys in SORTEDMULTI)
     uint8_t used[BITVECTOR_REAL_SIZE(MAX_PUBKEYS_PER_MULTISIG)];
-    memset(used, 0, sizeof(memset));
+    memset(used, 0, sizeof(used));
 
     for (int i = 0; i < policy->n; i++) {
         uint8_t compressed_pubkey[33];