build(variants): gate the coin engines behind the bitcoin-only build

deps/crypto/CMakeLists.txt

@@ -59,7 +59,7 @@ set(sources
     trezor-firmware/crypto/aes/aestab.c)
 
 # Pallas/Orchard curve arithmetic (~2.4k LOC) -- only the Zcash shielded engine
-# uses it. Excluded from the bitcoin-only image.
+# uses it. Excluded from the default and bitcoin-only images.
 if(${KK_ZCASH_PRIVACY})
   list(APPEND sources
       trezor-firmware/crypto/pallas.c

lib/firmware/CMakeLists.txt

@@ -2,52 +2,57 @@ set(sources
     app_confirm.c
     app_layout.c
     authenticator.c
-    binance.c
     bip85.c
     coins.c
     crypto.c
-    eip712.c
-    eos.c
-    eos-contracts/eosio.system.c
-    eos-contracts/eosio.token.c
-    ethereum.c
-    ethereum_contracts.c
-    ethereum_contracts/makerdao.c
-    ethereum_contracts/saproxy.c
-    ethereum_contracts/zxappliquid.c
-    ethereum_contracts/thortx.c
-    ethereum_contracts/zxliquidtx.c
-    ethereum_contracts/zxtransERC20.c
-    ethereum_contracts/zxswap.c
-    ethereum_tokens.c
     dice_input.c
     fsm.c
-    hive.c
     home_sm.c
-    mayachain.c
-    nano.c
-    osmosis.c
     passphrase_sm.c
     pin_sm.c
     policy.c
     recovery_cipher.c
     reset.c
-    ripple.c
-    ripple_base58.c
-    signed_metadata.c
     signing.c
-    signtx_tendermint.c
-    solana.c
     storage.c
-    tron.c
-    ton.c
-    tendermint.c
-    thorchain.c
     tiny-json.c
     transaction.c
     txin_check.c
     u2f.c)
 
+# Non-Bitcoin coin families -- excluded from the bitcoin-only image.
+if(NOT ${KK_BITCOIN_ONLY})
+  list(APPEND sources
+      binance.c
+      eip712.c
+      eos.c
+      eos-contracts/eosio.system.c
+      eos-contracts/eosio.token.c
+      ethereum.c
+      ethereum_contracts.c
+      ethereum_contracts/makerdao.c
+      ethereum_contracts/saproxy.c
+      ethereum_contracts/zxappliquid.c
+      ethereum_contracts/thortx.c
+      ethereum_contracts/zxliquidtx.c
+      ethereum_contracts/zxtransERC20.c
+      ethereum_contracts/zxswap.c
+      ethereum_tokens.c
+      signed_metadata.c
+      mayachain.c
+      nano.c
+      osmosis.c
+      ripple.c
+      ripple_base58.c
+      signtx_tendermint.c
+      solana.c
+      hive.c
+      tron.c
+      ton.c
+      tendermint.c
+      thorchain.c)
+endif()
+
 # Zcash shielded/Orchard engine -- transparent Zcash needs none of this.
 if(${KK_ZCASH_PRIVACY})
   list(APPEND sources zcash.c)

lib/firmware/fsm.c

@@ -117,6 +117,15 @@ static uint8_t msg_resp[MAX_FRAME_SIZE] __attribute__((aligned(4)));
     return;                                                            \
   }
 
+#define CHECK_NOT_BTC_ONLY_LOCKED                                   \
+  if (storage_isBitcoinOnlyLocked()) {                              \
+    fsm_sendFailure(FailureType_Failure_Other,                      \
+                    "Device holds a bitcoin-only wallet. Wipe the " \
+                    "device to use multi-chain firmware.");         \
+    layoutHome();                                                   \
+    return;                                                         \
+  }
+
 #define CHECK_PIN              \
   if (!pin_protect_cached()) { \
     layoutHome();              \
@@ -283,13 +292,16 @@ void fsm_msgClearSession(ClearSession* msg) {
   fsm_sendSuccess("Session cleared");
 }
 
+// Always-on handlers: Bitcoin/common (fsm_msg_coin), CipherKeyValue/identity
+// (fsm_msg_crypto), debug-link, and BIP85 -- none are coin engines.
 #include "fsm_msg_common.h"
 #include "fsm_msg_coin.h"
-#include "fsm_msg_ethereum.h"
-#include "fsm_msg_nano.h"
 #include "fsm_msg_crypto.h"
 #include "fsm_msg_debug.h"
 #include "fsm_msg_bip85.h"
+#if !BITCOIN_ONLY
+#include "fsm_msg_ethereum.h"
+#include "fsm_msg_nano.h"
 #include "fsm_msg_eos.h"
 #include "fsm_msg_cosmos.h"
 #include "fsm_msg_osmosis.h"
@@ -304,11 +316,22 @@ void fsm_msgClearSession(ClearSession* msg) {
 #include "fsm_msg_hive.h"
 /* After fsm_msg_solana.h: reuses its base58 helper and the KKSOLSC1 parser. */
 #include "fsm_msg_clearsign_attestor.h"
+#else
+// Bitcoin-only: the coin engines above are compiled out, but the always-on
+// Initialize/ClearSession/Cancel handlers still call their *_abort() hooks,
+// and factory-reset calls signed_metadata_clear_signers() (EVM clearsign).
+// With no state to reset, no-ops are correct.
+void ethereum_signing_abort(void) {}
+void tendermint_signAbort(void) {}
+void eos_signingAbort(void) {}
+void signed_metadata_clear_signers(void) {}
+#endif  // !BITCOIN_ONLY
 #if ZCASH_PRIVACY
 #include "fsm_msg_zcash.h"
 #else
 // Zcash shielded/Orchard engine compiled out. The always-on
 // Initialize/ClearSession/Cancel handlers still call zcash_signing_abort();
-// with no privacy state to reset, a no-op is correct.
+// with no privacy state to reset, a no-op is correct. (Bitcoin-only forces
+// privacy off, so this stub also covers the bitcoin-only image.)
 void zcash_signing_abort(void) {}
 #endif

lib/firmware/fsm_msg_coin.h

@@ -188,6 +188,21 @@ static bool path_mismatched(const CoinType* coin, const GetAddress* msg) {
     return mismatch;
   }
 
+  // m/86' : BIP86 Taproot
+  // m / purpose' / bip44_account_path' / account' / change / address_index
+  if (msg->address_n[0] == (0x80000000 + 86)) {
+    mismatch |= (msg->script_type != InputScriptType_SPENDTAPROOT);
+    mismatch |= !coin->has_segwit || !coin->segwit;
+    mismatch |= !coin->has_bech32_prefix;
+    mismatch |= !coin->has_taproot || !coin->taproot;
+    mismatch |= (msg->address_n_count != 5);
+    mismatch |= (msg->address_n[1] != coin->bip44_account_path);
+    mismatch |= (msg->address_n[2] & 0x80000000) == 0;
+    mismatch |= (msg->address_n[3] & 0x80000000) == 0x80000000;
+    mismatch |= (msg->address_n[4] & 0x80000000) == 0x80000000;
+    return mismatch;
+  }
+
   return false;
 }
 
@@ -270,8 +285,8 @@ void fsm_msgSignMessage(SignMessage* msg) {
 
   CHECK_INITIALIZED
 
-  if (!confirm(ButtonRequestType_ButtonRequest_SignMessage, "Sign Message",
-               "%s", (char*)msg->message.bytes)) {
+  if (!confirm_bytes(ButtonRequestType_ButtonRequest_SignMessage,
+                     "Sign Message", msg->message.bytes, msg->message.size)) {
     fsm_sendFailure(FailureType_Failure_ActionCancelled,
                     "Sign message cancelled");
     layoutHome();
@@ -325,8 +340,9 @@ void fsm_msgVerifyMessage(VerifyMessage* msg) {
       layoutHome();
       return;
     }
-    if (!review(ButtonRequestType_ButtonRequest_Other, "Message Verified", "%s",
-                (char*)msg->message.bytes)) {
+    if (!confirm_bytes(ButtonRequestType_ButtonRequest_Other,
+                       "Message Verified", msg->message.bytes,
+                       msg->message.size)) {
       fsm_sendFailure(FailureType_Failure_ActionCancelled,
                       _("Action cancelled by user"));
       layoutHome();

lib/firmware/fsm_msg_common.h

@@ -49,8 +49,53 @@ void fsm_msgGetFeatures(GetFeatures* msg) {
 
   /* Variant Name */
   resp->has_firmware_variant = true;
-  strlcpy(resp->firmware_variant, variant_getName(),
-          sizeof(resp->firmware_variant));
+#if BITCOIN_ONLY
+  /* Bitcoin-only build. Uses the established KeepKeyBTC / EmulatorBTC names so
+     existing clients (python-keepkey requires_fullFeature, etc.) skip
+     multi-chain-only behaviour and never offer multi-chain firmware. The lock
+     sentinel is reachable here too: a NEWER bitcoin-only wallet than this
+     firmware understands refuses to load (storage_isBitcoinOnlyLocked), and
+     hosts need the same signal the other builds emit. */
+  if (storage_isBitcoinOnlyLocked()) {
+    strlcpy(resp->firmware_variant, "bitcoin-only-locked",
+            sizeof(resp->firmware_variant));
+  } else {
+#ifdef EMULATOR
+    strlcpy(resp->firmware_variant, "EmulatorBTC",
+            sizeof(resp->firmware_variant));
+#else
+    strlcpy(resp->firmware_variant, "KeepKeyBTC",
+            sizeof(resp->firmware_variant));
+#endif
+  }
+#elif ZCASH_PRIVACY
+  /* Zcash/Orchard privacy build. Distinct variant name so hosts can gate
+     variant-partitioned features — the clearsign session icon cache is
+     compiled out of this build to fit SRAM (identities still work; persistent
+     identity icons still render from storage). */
+  if (storage_isBitcoinOnlyLocked()) {
+    strlcpy(resp->firmware_variant, "bitcoin-only-locked",
+            sizeof(resp->firmware_variant));
+  } else {
+#ifdef EMULATOR
+    strlcpy(resp->firmware_variant, "EmulatorZcash",
+            sizeof(resp->firmware_variant));
+#else
+    strlcpy(resp->firmware_variant, "KeepKeyZcash",
+            sizeof(resp->firmware_variant));
+#endif
+  }
+#else
+  if (storage_isBitcoinOnlyLocked()) {
+    /* Multi-chain firmware refusing to touch a bitcoin-only wallet; a wipe
+       is required before this device can be used. */
+    strlcpy(resp->firmware_variant, "bitcoin-only-locked",
+            sizeof(resp->firmware_variant));
+  } else {
+    strlcpy(resp->firmware_variant, variant_getName(),
+            sizeof(resp->firmware_variant));
+  }
+#endif
 
   /* Security settings */
   resp->has_pin_protection = true;
@@ -157,8 +202,10 @@ void fsm_msgGetCoinTable(GetCoinTable* msg) {
     for (size_t i = 0; i < msg->end - msg->start; i++) {
       if (msg->start + i < COINS_COUNT) {
         resp->table[i] = coins[msg->start + i];
+#if !BITCOIN_ONLY
       } else if (msg->start + i - COINS_COUNT < TOKENS_COUNT) {
         coinFromToken(&resp->table[i], &tokens[msg->start + i - COINS_COUNT]);
+#endif
       }
     }
   }
@@ -334,6 +381,7 @@ void fsm_msgPing(Ping* msg) {
 }
 
 void fsm_msgChangePin(ChangePin* msg) {
+  CHECK_NOT_BTC_ONLY_LOCKED
   bool removal = msg->has_remove && msg->remove;
   bool confirmed = false;
 
@@ -384,6 +432,7 @@ void fsm_msgChangePin(ChangePin* msg) {
 }
 
 void fsm_msgChangeWipeCode(ChangeWipeCode* msg) {
+  CHECK_NOT_BTC_ONLY_LOCKED
   bool removal = msg->has_remove && msg->remove;
   bool confirmed = false;
 
@@ -616,6 +665,7 @@ void fsm_msgGetEntropy(GetEntropy* msg) {
 }
 
 void fsm_msgLoadDevice(LoadDevice* msg) {
+  CHECK_NOT_BTC_ONLY_LOCKED
   CHECK_NOT_INITIALIZED
 
   if (!confirm_load_device(msg->has_node)) {
@@ -644,6 +694,7 @@ void fsm_msgLoadDevice(LoadDevice* msg) {
 }
 
 void fsm_msgResetDevice(ResetDevice* msg) {
+  CHECK_NOT_BTC_ONLY_LOCKED
   CHECK_NOT_INITIALIZED
 
   // display_random remains in the wire schema for host compatibility, but is
@@ -676,10 +727,12 @@ void fsm_msgCancel(Cancel* msg) {
   ethereum_signing_abort();
   tendermint_signAbort();
   eos_signingAbort();
+  zcash_signing_abort();
   fsm_sendFailure(FailureType_Failure_ActionCancelled, "Aborted");
 }
 
 void fsm_msgApplySettings(ApplySettings* msg) {
+  CHECK_NOT_BTC_ONLY_LOCKED
   if (msg->has_label) {
     if (!confirm(ButtonRequestType_ButtonRequest_ChangeLabel, "Change Label",
                  "Do you want to change the label to \"%s\"?", msg->label)) {
@@ -770,6 +823,7 @@ void fsm_msgApplySettings(ApplySettings* msg) {
 }
 
 void fsm_msgRecoveryDevice(RecoveryDevice* msg) {
+  CHECK_NOT_BTC_ONLY_LOCKED
   if (msg->has_dry_run && msg->dry_run) {
     CHECK_INITIALIZED
   } else {
@@ -800,6 +854,7 @@ void fsm_msgCharacterAck(CharacterAck* msg) {
 }
 
 void fsm_msgApplyPolicies(ApplyPolicies* msg) {
+  CHECK_NOT_BTC_ONLY_LOCKED
   CHECK_PARAM(msg->policy_count > 0, "No policies provided");
 
   for (size_t i = 0; i < msg->policy_count; ++i) {
@@ -851,6 +906,17 @@ void fsm_msgApplyPolicies(ApplyPolicies* msg) {
 
   storage_commit();
 
+  /* Runtime clearsign identities are an AdvancedMode capability. Revoking the
+   * policy also revokes every RAM-only signer immediately, so toggling the
+   * policy off cannot leave a previously approved trust anchor active. */
+  for (size_t i = 0; i < msg->policy_count; ++i) {
+    if (strcmp(msg->policy[i].policy_name, "AdvancedMode") == 0 &&
+        !msg->policy[i].enabled) {
+      signed_metadata_clear_signers();
+      break;
+    }
+  }
+
   fsm_sendSuccess("Policies applied");
   layoutHome();
 }