feat(legacy): Implement AuthorizeCoinJoin.

legacy/firmware/config.c

@@ -128,6 +128,8 @@ typedef struct {
   uint32_t last_use;
   uint8_t seed[64];
   secbool seedCached;
+  MessageType authorization_type;
+  AuthorizeCoinJoin coinjoin_authorization;
 } Session;
 
 static void session_clearCache(Session *session);
@@ -429,6 +431,9 @@ void session_clearCache(Session *session) {
   memzero(session->id, sizeof(session->id));
   memzero(session->seed, sizeof(session->seed));
   session->seedCached = false;
+  session->authorization_type = 0;
+  memzero(&session->coinjoin_authorization,
+          sizeof(session->coinjoin_authorization));
 }
 
 void config_lockDevice(void) {
@@ -641,6 +646,50 @@ const uint8_t *config_getSeed(void) {
   return NULL;
 }
 
+bool config_setCoinJoinAuthorization(const AuthorizeCoinJoin *authorization) {
+  if (activeSessionCache == NULL) {
+    fsm_sendFailure(FailureType_Failure_InvalidSession, "Invalid session");
+    return false;
+  }
+
+  if (authorization != NULL) {
+    activeSessionCache->authorization_type =
+        MessageType_MessageType_AuthorizeCoinJoin;
+    memcpy(&activeSessionCache->coinjoin_authorization, authorization,
+           sizeof(AuthorizeCoinJoin));
+  } else {
+    activeSessionCache->authorization_type = 0;
+    memzero(&activeSessionCache->coinjoin_authorization,
+            sizeof(AuthorizeCoinJoin));
+  }
+
+  return true;
+}
+
+MessageType config_getAuthorizationType(void) {
+  if (activeSessionCache == NULL) {
+    return 0;
+  }
+
+  return activeSessionCache->authorization_type;
+}
+
+const AuthorizeCoinJoin *config_getCoinJoinAuthorization(void) {
+  if (activeSessionCache == NULL) {
+    fsm_sendFailure(FailureType_Failure_InvalidSession, "Invalid session");
+    return NULL;
+  }
+
+  if (activeSessionCache->authorization_type !=
+      MessageType_MessageType_AuthorizeCoinJoin) {
+    fsm_sendFailure(FailureType_Failure_InvalidSession,
+                    "Coinjoin not authorized");
+    return NULL;
+  }
+
+  return &activeSessionCache->coinjoin_authorization;
+}
+
 static bool config_loadNode(const StorageHDNode *node, const char *curve,
                             HDNode *out) {
   return hdnode_from_xprv(node->depth, node->child_num, node->chain_code.bytes,

legacy/firmware/config.h

@@ -21,8 +21,10 @@
 #define __CONFIG_H__
 
 #include "bip32.h"
+#include "messages-bitcoin.pb.h"
 #include "messages-common.pb.h"
 #include "messages-management.pb.h"
+#include "messages.pb.h"
 
 #define STORAGE_FIELD(TYPE, NAME) \
   bool has_##NAME;                \
@@ -102,6 +104,10 @@ void config_loadDevice(const LoadDevice *msg);
 
 const uint8_t *config_getSeed(void);
 
+bool config_setCoinJoinAuthorization(const AuthorizeCoinJoin *authorization);
+MessageType config_getAuthorizationType(void);
+const AuthorizeCoinJoin *config_getCoinJoinAuthorization(void);
+
 bool config_getU2FRoot(HDNode *node);
 bool config_getRootNode(HDNode *node, const char *curve);
 

legacy/firmware/fsm.h

@@ -29,6 +29,9 @@
 #include "messages-nem.pb.h"
 #include "messages-stellar.pb.h"
 
+// CoinJoin fee rate multiplier.
+#define FEE_RATE_DECIMALS (1000000)
+
 // message functions
 
 void fsm_sendSuccess(const char *text);
@@ -82,6 +85,8 @@ void fsm_msgSignMessage(const SignMessage *msg);
 void fsm_msgVerifyMessage(const VerifyMessage *msg);
 void fsm_msgGetOwnershipId(const GetOwnershipId *msg);
 void fsm_msgGetOwnershipProof(const GetOwnershipProof *msg);
+void fsm_msgAuthorizeCoinJoin(const AuthorizeCoinJoin *msg);
+void fsm_msgCancelAuthorization(const CancelAuthorization *msg);
 
 // crypto
 void fsm_msgCipherKeyValue(const CipherKeyValue *msg);

legacy/firmware/fsm_msg_coin.h

@@ -557,3 +557,147 @@ void fsm_msgGetOwnershipProof(const GetOwnershipProof *msg) {
   msg_write(MessageType_MessageType_OwnershipProof, resp);
   layoutHome();
 }
+
+void fsm_msgAuthorizeCoinJoin(const AuthorizeCoinJoin *msg) {
+  CHECK_INITIALIZED
+
+  CHECK_PIN
+
+  const size_t MAX_COORDINATOR_LEN = 36;
+  const uint64_t MAX_ROUNDS = 500;
+  const uint64_t MAX_COORDINATOR_FEE_RATE = 5 * FEE_RATE_DECIMALS;  // 5 %
+
+  const CoinInfo *coin = fsm_getCoin(msg->has_coin_name, msg->coin_name);
+  if (!coin) {
+    return;
+  }
+
+  if (strnlen(msg->coordinator, sizeof(msg->coordinator)) >
+      MAX_COORDINATOR_LEN) {
+    fsm_sendFailure(FailureType_Failure_DataError,
+                    _("Invalid coordinator name."));
+    layoutHome();
+    return;
+  }
+
+  for (size_t i = 0; msg->coordinator[i] != '\0'; ++i) {
+    if (msg->coordinator[i] < 32 || msg->coordinator[i] > 126) {
+      fsm_sendFailure(FailureType_Failure_DataError,
+                      _("Invalid coordinator name."));
+      layoutHome();
+      return;
+    }
+  }
+
+  if (msg->max_rounds < 1) {
+    fsm_sendFailure(FailureType_Failure_DataError,
+                    _("Invalid number of rounds."));
+    layoutHome();
+    return;
+  }
+
+  bool safety_checks_is_strict =
+      (config_getSafetyCheckLevel() == SafetyCheckLevel_Strict);
+
+  if (msg->max_rounds > MAX_ROUNDS && safety_checks_is_strict) {
+    fsm_sendFailure(FailureType_Failure_DataError,
+                    _("The number of rounds is unexpectedly large."));
+    layoutHome();
+    return;
+  }
+
+  if (msg->max_coordinator_fee_rate > MAX_COORDINATOR_FEE_RATE &&
+      safety_checks_is_strict) {
+    fsm_sendFailure(FailureType_Failure_DataError,
+                    _("The coordination fee rate is unexpectedly large."));
+    layoutHome();
+    return;
+  }
+
+  if (msg->max_fee_per_kvbyte > 10 * coin->maxfee_kb &&
+      safety_checks_is_strict) {
+    fsm_sendFailure(FailureType_Failure_DataError,
+                    _("The fee per vbyte is unexpectedly large."));
+    layoutHome();
+    return;
+  }
+
+  if (msg->address_n_count == 0) {
+    fsm_sendFailure(FailureType_Failure_DataError,
+                    _("Empty path not allowed."));
+    layoutHome();
+    return;
+  }
+
+  if (msg->address_n[0] != PATH_SLIP25_PURPOSE && safety_checks_is_strict) {
+    fsm_sendFailure(FailureType_Failure_DataError, _("Forbidden key path."));
+    layoutHome();
+    return;
+  }
+
+  layoutAuthorizeCoinJoin(coin, msg->max_rounds, msg->max_fee_per_kvbyte);
+  if (!protectButton(ButtonRequestType_ButtonRequest_ProtectCall, false)) {
+    fsm_sendFailure(FailureType_Failure_ActionCancelled, NULL);
+    layoutHome();
+    return;
+  }
+
+  bool path_warning_shown = false;
+  if (msg->address_n[0] != PATH_SLIP25_PURPOSE) {
+    if (!fsm_layoutPathWarning()) {
+      layoutHome();
+      return;
+    }
+    path_warning_shown = true;
+  }
+
+  // AuthorizeCoinJoin contains only the path prefix without change and index.
+  if ((size_t)(msg->address_n_count + 2) >
+      sizeof(msg->address_n) / sizeof(msg->address_n[0])) {
+    fsm_sendFailure(FailureType_Failure_DataError, _("Forbidden key path."));
+    layoutHome();
+    return;
+  }
+
+  if (!fsm_checkCoinPath(coin, msg->script_type, msg->address_n_count + 2,
+                         msg->address_n, false, !path_warning_shown)) {
+    layoutHome();
+    return;
+  }
+
+  if (msg->max_fee_per_kvbyte > coin->maxfee_kb) {
+    layoutFeeRateOverThreshold(coin, msg->max_fee_per_kvbyte);
+    if (!protectButton(ButtonRequestType_ButtonRequest_FeeOverThreshold,
+                       false)) {
+      fsm_sendFailure(FailureType_Failure_ActionCancelled, NULL);
+      layoutHome();
+      return;
+    }
+  }
+
+  // Cache the seed.
+  if (config_getSeed() == NULL) {
+    layoutHome();
+    return;
+  }
+
+  if (!config_setCoinJoinAuthorization(msg)) {
+    layoutHome();
+    return;
+  }
+
+  fsm_sendSuccess(_("Coinjoin authorized"));
+  layoutHome();
+}
+
+void fsm_msgCancelAuthorization(const CancelAuthorization *msg) {
+  (void)msg;
+
+  if (!config_setCoinJoinAuthorization(NULL)) {
+    layoutHome();
+    return;
+  }
+
+  fsm_sendSuccess(_("Authorization cancelled"));
+  layoutHome();
+}

legacy/firmware/layout2.c

@@ -510,9 +510,10 @@ static uint64_t div_round(uint64_t numer, uint64_t denom) {
   return numer / denom + (2 * (numer % denom) >= denom);
 }
 
-static bool formatFeeRate(uint64_t fee, uint64_t tx_weight, char *output,
-                          size_t output_length, bool segwit) {
-  // Convert transaction weight to virtual transaction size, which is is defined
+static bool formatComputedFeeRate(uint64_t fee, uint64_t tx_weight,
+                                  char *output, size_t output_length,
+                                  bool segwit, bool parentheses) {
+  // Convert transaction weight to virtual transaction size, which is defined
   // as tx_weight / 4 rounded up to the next integer.
   // https://github.com/bitcoin/bips/blob/master/bip-0141.mediawiki#transaction-size-calculations
   uint64_t tx_size = (tx_weight + 3) / 4;
@@ -522,9 +523,27 @@ static bool formatFeeRate(uint64_t fee, uint64_t tx_weight, char *output,
   // two decimal digits.
   uint64_t fee_rate_multiplied = div_round(100 * fee, tx_size);
 
-  return bn_format_amount(fee_rate_multiplied, "(",
-                          segwit ? " sat/vB)" : " sat/B)", 2, output,
-                          output_length) != 0;
+  size_t length =
+      bn_format_amount(fee_rate_multiplied, parentheses ? "(" : NULL,
+                       segwit ? " sat/vB" : " sat/B", 2, output, output_length);
+  if (length == 0) {
+    return false;
+  }
+
+  if (parentheses) {
+    if (length + 2 > output_length) {
+      return false;
+    }
+    output[length] = ')';
+    output[length + 1] = '\0';
+  }
+  return true;
+}
+
+static bool formatFeeRate(uint64_t fee_per_kvbyte, char *output,
+                          size_t output_length, bool segwit) {
+  return formatComputedFeeRate(fee_per_kvbyte, 4000, output, output_length,
+                               segwit, false);
 }
 
 void layoutConfirmTx(const CoinInfo *coin, AmountUnit amount_unit,
@@ -544,8 +563,8 @@ void layoutConfirmTx(const CoinInfo *coin, AmountUnit amount_unit,
     bool show_fee_rate = total_in >= total_out;
 
     if (show_fee_rate) {
-      formatFeeRate(total_in - total_out, tx_weight, str_fee_rate,
-                    sizeof(str_fee_rate), coin->has_segwit);
+      formatComputedFeeRate(total_in - total_out, tx_weight, str_fee_rate,
+                            sizeof(str_fee_rate), coin->has_segwit, true);
     }
 
     layoutDialogSwipe(&bmp_icon_question, _("Cancel"), _("Confirm"), NULL,
@@ -621,8 +640,8 @@ void layoutConfirmModifyFee(const CoinInfo *coin, AmountUnit amount_unit,
 
   char str_fee_rate[32] = {0};
 
-  formatFeeRate(fee_new, tx_weight, str_fee_rate, sizeof(str_fee_rate),
-                coin->has_segwit);
+  formatComputedFeeRate(fee_new, tx_weight, str_fee_rate, sizeof(str_fee_rate),
+                        coin->has_segwit, true);
 
   layoutDialogSwipe(&bmp_icon_question, _("Cancel"), _("Confirm"), NULL,
                     question, str_fee_change, _("Transaction fee:"),
@@ -638,6 +657,15 @@ void layoutFeeOverThreshold(const CoinInfo *coin, AmountUnit amount_unit,
                     _("Send anyway?"), NULL);
 }
 
+void layoutFeeRateOverThreshold(const CoinInfo *coin, uint32_t fee_per_kvbyte) {
+  char str_fee_rate[32] = {0};
+  formatFeeRate(fee_per_kvbyte, str_fee_rate, sizeof(str_fee_rate),
+                coin->has_segwit);
+  layoutDialogSwipe(&bmp_icon_question, _("Cancel"), _("Confirm"), NULL,
+                    _("Fee rate"), str_fee_rate, _("is unexpectedly high."),
+                    NULL, _("Proceed anyway?"), NULL);
+}
+
 void layoutChangeCountOverThreshold(uint32_t change_count) {
   char str_change[21] = {0};
   snprintf(str_change, sizeof(str_change), "There are %" PRIu32, change_count);
@@ -679,6 +707,20 @@ void layoutConfirmNondefaultLockTime(uint32_t lock_time,
   }
 }
 
+void layoutAuthorizeCoinJoin(const CoinInfo *coin, uint64_t max_rounds,
+                             uint32_t max_fee_per_kvbyte) {
+  char str_max_rounds[32] = {0};
+  char str_fee_rate[32] = {0};
+  bn_format_amount(max_rounds, NULL, NULL, 0, str_max_rounds,
+                   sizeof(str_max_rounds));
+  formatFeeRate(max_fee_per_kvbyte, str_fee_rate, sizeof(str_fee_rate),
+                coin->has_segwit);
+  layoutDialogSwipe(&bmp_icon_question, _("Cancel"), _("Confirm"),
+                    _("Authorize coinjoin"), _("Maximum rounds:"),
+                    str_max_rounds, _("Maximum mining fee:"), str_fee_rate,
+                    NULL, NULL);
+}
+
 void layoutVerifyAddress(const CoinInfo *coin, const char *address) {
   render_address_dialog(coin, address, _("Confirm address?"),
                         _("Message signed by:"), 0);

legacy/firmware/layout2.h

@@ -69,10 +69,13 @@ void layoutConfirmModifyFee(const CoinInfo *coin, AmountUnit amount_unit,
                             uint64_t tx_weight);
 void layoutFeeOverThreshold(const CoinInfo *coin, AmountUnit amount_unit,
                             uint64_t fee);
+void layoutFeeRateOverThreshold(const CoinInfo *coin, uint32_t fee_per_kvbyte);
 void layoutChangeCountOverThreshold(uint32_t change_count);
 void layoutConfirmUnverifiedExternalInputs(void);
 void layoutConfirmNondefaultLockTime(uint32_t lock_time,
                                      bool lock_time_disabled);
+void layoutAuthorizeCoinJoin(const CoinInfo *coin, uint64_t max_rounds,
+                             uint32_t max_fee_per_kvbyte);
 void layoutVerifyAddress(const CoinInfo *coin, const char *address);
 void layoutCipherKeyValue(bool encrypt, const char *key);
 void layoutEncryptMessage(const uint8_t *msg, uint32_t len, bool signing);

legacy/firmware/protob/Makefile

@@ -4,8 +4,7 @@ endif
 
 SKIPPED_MESSAGES := Binance Cardano DebugMonero Eos Monero Ontology Ripple SdProtect Tezos WebAuthn \
 	DebugLinkRecordScreen DebugLinkEraseSdCard DebugLinkWatchLayout \
-	AuthorizeCoinJoin DoPreauthorized \
-	CancelAuthorization DebugLinkLayout GetNonce SetBusy UnlockPath \
+	DoPreauthorized DebugLinkLayout GetNonce SetBusy UnlockPath \
 	TxAckInput TxAckOutput TxAckPrev TxAckPaymentRequest \
 	EthereumSignTypedData EthereumTypedDataStructRequest EthereumTypedDataStructAck \
 	EthereumTypedDataValueRequest EthereumTypedDataValueAck

legacy/firmware/protob/messages-bitcoin.options

@@ -92,8 +92,12 @@ GetOwnershipProof.commitment_data                           max_size:70
 OwnershipProof.ownership_proof                              max_size:147
 OwnershipProof.signature                                    max_size:71
 
+AuthorizeCoinJoin.coordinator                               max_size:37
+AuthorizeCoinJoin.address_n                                 max_count:8
+AuthorizeCoinJoin.coin_name                                 max_size:21
+
+
 # Unused messages.
-AuthorizeCoinJoin                                           skip_message:true
 TxAckPaymentRequest                                         skip_message:true
 PaymentRequestMemo                                          skip_message:true
 CoinJoinRequest                                             skip_message:true