feat: EVM clear signing — EthBlindSigning policy + signed metadata

include/keepkey/board/confirm_sm.h

@@ -96,6 +96,10 @@ bool confirm(ButtonRequestType type, const char *request_title,
              const char *request_body, ...)
     __attribute__((format(printf, 3, 4)));
 
+bool confirm_with_icon(ButtonRequestType type, IconType iconNum,
+                       const char *request_title, const char *request_body,
+                       ...) __attribute__((format(printf, 4, 5)));
+
 bool confirm_constant_power(ButtonRequestType type, const char *request_title, const char *request_body,
              ...) __attribute__((format(printf, 3, 4)));
 

include/keepkey/board/layout.h

@@ -79,6 +79,7 @@ typedef enum {
 typedef enum {
   NO_ICON=0,
   ETHEREUM_ICON,
+  VERIFIED_ICON,
 } IconType;
 
 typedef void (*AnimateCallback)(void *data, uint32_t duration,

include/keepkey/firmware/policy.h

@@ -33,6 +33,7 @@ static const PolicyType policies[] = {
     {true, "Experimental", true, false},
     {true, "AdvancedMode", true, false},
     {true, "SolBlindSign", true, false},
+    {true, "EthBlindSign", true, true},
 };
 
 int run_policy_compile_output(const CoinType *coin, const HDNode *root,

include/keepkey/firmware/signed_metadata.h

@@ -0,0 +1,62 @@
+#ifndef KEEPKEY_FIRMWARE_SIGNED_METADATA_H
+#define KEEPKEY_FIRMWARE_SIGNED_METADATA_H
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+typedef struct _EthereumSignTx EthereumSignTx;
+
+#define METADATA_MAX_ARGS 8
+#define METADATA_MAX_METHOD_LEN 64
+#define METADATA_MAX_ARG_NAME_LEN 32
+#define METADATA_MAX_ARG_VALUE_LEN 32
+#define METADATA_MAX_KEYS 4
+
+typedef enum {
+  METADATA_OPAQUE = 0,
+  METADATA_VERIFIED = 1,
+  METADATA_MALFORMED = 2,
+} MetadataClassification;
+
+typedef enum {
+  ARG_FORMAT_RAW = 0,
+  ARG_FORMAT_ADDRESS = 1,
+  ARG_FORMAT_AMOUNT = 2,
+  ARG_FORMAT_BYTES = 3,
+} ArgFormat;
+
+typedef struct {
+  char name[METADATA_MAX_ARG_NAME_LEN + 1];
+  ArgFormat format;
+  uint8_t value[METADATA_MAX_ARG_VALUE_LEN];
+  uint16_t value_len;
+} MetadataArg;
+
+typedef struct {
+  uint8_t version;
+  uint32_t chain_id;
+  uint8_t contract_address[20];
+  uint8_t selector[4];
+  uint8_t tx_hash[32];
+  char method_name[METADATA_MAX_METHOD_LEN + 1];
+  uint8_t num_args;
+  MetadataArg args[METADATA_MAX_ARGS];
+  MetadataClassification classification;
+  uint32_t timestamp;
+  uint8_t key_id;
+  uint8_t signature[64];
+  uint8_t recovery;
+} SignedMetadata;
+
+bool signed_metadata_available(void);
+void signed_metadata_clear(void);
+MetadataClassification signed_metadata_process(const uint8_t *payload,
+                                              size_t payload_len,
+                                              uint8_t key_id);
+bool signed_metadata_matches_tx(const EthereumSignTx *msg,
+                                const uint8_t *tx_hash);
+bool signed_metadata_confirm(void);
+const SignedMetadata *signed_metadata_get(void);
+
+#endif

include/keepkey/transport/messages-ethereum.options

@@ -47,3 +47,6 @@ Ethereum712TypesValues.eip712types               max_size:2048
 Ethereum712TypesValues.eip712primetype           max_size:80
 Ethereum712TypesValues.eip712data			          max_size:2048
 
+EthereumTxMetadata.signed_payload                max_size:1024
+EthereumMetadataAck.display_summary              max_size:32
+

include/keepkey/transport/messages.options

@@ -5,7 +5,7 @@ Features.label				max_size:33
 Features.coins				max_count:0
 Features.revision			max_size:41
 Features.bootloader_hash		max_size:32
-Features.policies			max_count:5
+Features.policies			max_count:6
 Features.model              max_size:32
 Features.firmware_variant    max_size:32
 Features.firmware_hash		max_size:32

lib/board/confirm_sm.c

@@ -318,6 +318,28 @@ bool confirm(ButtonRequestType type, const char *request_title, const char *requ
     return ret;
 }
 
+bool confirm_with_icon(ButtonRequestType type, IconType iconNum,
+                       const char *request_title, const char *request_body,
+                       ...)
+{
+    button_request_acked = false;
+
+    va_list vl;
+    va_start(vl, request_body);
+    vsnprintf(strbuf, sizeof(strbuf), request_body, vl);
+    va_end(vl);
+
+    ButtonRequest resp;
+    memset(&resp, 0, sizeof(ButtonRequest));
+    resp.has_code = true;
+    resp.code = type;
+    msg_write(MessageType_MessageType_ButtonRequest, &resp);
+
+    bool ret = confirm_helper(request_title, strbuf, &layout_standard_notification, false, iconNum, false);
+    memzero(strbuf, sizeof(strbuf));
+    return ret;
+}
+
 bool confirm_constant_power(ButtonRequestType type, const char *request_title, const char *request_body,
              ...)
 {

lib/board/layout.c

@@ -331,6 +331,12 @@ void layout_add_icon(IconType type) {
       draw_bitmap_mono_rle(canvas, get_ethereum_icon_frame(), false);
       break;
 
+    case VERIFIED_ICON:
+      /* TODO: replace with dedicated verified/shield bitmap.
+       * Using Ethereum icon as placeholder until bitmap is designed. */
+      draw_bitmap_mono_rle(canvas, get_ethereum_icon_frame(), false);
+      break;
+
     default:
       /* no action requires */
       break;

lib/firmware/CMakeLists.txt

@@ -29,6 +29,7 @@ if(NOT "${COIN_SUPPORT}" STREQUAL "BTC")
       eos-contracts/eosio.token.c
       ethereum.c
       ethereum_contracts.c
+      signed_metadata.c
       ethereum_contracts/makerdao.c
       ethereum_contracts/saproxy.c
       ethereum_contracts/zxappliquid.c

lib/firmware/ethereum.c

@@ -33,6 +33,7 @@
 #include "keepkey/firmware/eip712.h"
 #include "keepkey/firmware/ethereum_contracts.h"
 #include "keepkey/firmware/ethereum_contracts/makerdao.h"
+#include "keepkey/firmware/signed_metadata.h"
 #include "keepkey/firmware/ethereum_tokens.h"
 #include "keepkey/firmware/storage.h"
 #include "keepkey/firmware/thorchain.h"
@@ -689,6 +690,26 @@ void ethereum_signing_init(EthereumSignTx *msg, const HDNode *node,
     data_needs_confirm = false;
   }
 
+  // Signed metadata clear signing (backwards compatible).
+  // Only fires if host sent EthereumTxMetadata before this EthereumSignTx.
+  if (data_needs_confirm && data_total > 0 && signed_metadata_available()) {
+    if (signed_metadata_matches_tx(msg, NULL)) {
+      if (signed_metadata_confirm()) {
+        needs_confirm = false;
+        data_needs_confirm = false;
+      } else {
+        fsm_sendFailure(FailureType_Failure_ActionCancelled,
+                        "Signing cancelled by user");
+        ethereum_signing_abort();
+        signed_metadata_clear();
+        return;
+      }
+    }
+  }
+  // Always clear metadata after use — prevents stale data from persisting
+  // when contractHandled or ERC-20 paths bypass the metadata check above.
+  signed_metadata_clear();
+
   // detect ERC-20 token
   if (data_total == 68 && ethereum_isStandardERC20Transfer(msg)) {
     token = tokenByChainAddress(chain_id, msg->to.bytes);
@@ -734,10 +755,19 @@ void ethereum_signing_init(EthereumSignTx *msg, const HDNode *node,
 
   memset(confirm_body_message, 0, sizeof(confirm_body_message));
   if (token == NULL && data_total > 0 && data_needs_confirm) {
+    // EthBlindSign policy: hard gate when disabled
+    if (!storage_isPolicyEnabled("EthBlindSign")) {
+      (void)review(ButtonRequestType_ButtonRequest_Other, "Blocked",
+                   "Blind signing is disabled. Enable "
+                   "'EthBlindSign' policy to allow.");
+      fsm_sendFailure(FailureType_Failure_ActionCancelled,
+                      "Blind signing disabled by policy");
+      ethereum_signing_abort();
+      return;
+    }
+
     // KeepKey custom: warn the user that they're trying to do something
-    // that is potentially dangerous. People (generally) aren't great at
-    // parsing raw transaction data, and we can't effectively show them
-    // what they're about to do in the general case.
+    // that is potentially dangerous.
     if (!storage_isPolicyEnabled("AdvancedMode")) {
       (void)review(
           ButtonRequestType_ButtonRequest_Other, "Warning",

lib/firmware/fsm.c

@@ -100,6 +100,11 @@
 #include "messages-zcash.pb.h"
 #endif // BITCOIN_ONLY
 
+// Forward declaration for handler defined in fsm_msg_ethereum.h
+#ifndef BITCOIN_ONLY
+void fsm_msgEthereumTxMetadata(const EthereumTxMetadata *);
+#endif
+
 #define _(X) (X)
 
 static uint8_t msg_resp[MAX_FRAME_SIZE] __attribute__((aligned(4)));

lib/firmware/fsm_msg_ethereum.h

@@ -19,6 +19,42 @@
  * along with this library.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include "keepkey/firmware/signed_metadata.h"
+
+void fsm_msgEthereumTxMetadata(const EthereumTxMetadata *msg) {
+    CHECK_INITIALIZED
+    CHECK_PIN
+
+    RESP_INIT(EthereumMetadataAck);
+
+    MetadataClassification result = signed_metadata_process(
+        msg->signed_payload.bytes,
+        msg->signed_payload.size,
+        msg->has_key_id ? msg->key_id : 0
+    );
+
+    resp->classification = (uint32_t)result;
+    resp->has_display_summary = true;
+
+    switch (result) {
+        case METADATA_VERIFIED:
+            strlcpy(resp->display_summary, "Verified",
+                    sizeof(resp->display_summary));
+            break;
+        case METADATA_OPAQUE:
+            strlcpy(resp->display_summary, "Unverified",
+                    sizeof(resp->display_summary));
+            break;
+        case METADATA_MALFORMED:
+        default:
+            strlcpy(resp->display_summary, "Invalid",
+                    sizeof(resp->display_summary));
+            break;
+    }
+
+    msg_write(MessageType_MessageType_EthereumMetadataAck, resp);
+}
+
 static int process_ethereum_xfer(const CoinType *coin, EthereumSignTx *msg) {
   if (!ethereum_isStandardERC20Transfer(msg) && msg->data_length != 0)
     return TXOUT_COMPILE_ERROR;

lib/firmware/messagemap.def

@@ -37,6 +37,7 @@
     MSG_IN(MessageType_MessageType_EthereumGetAddress,              EthereumGetAddress,          fsm_msgEthereumGetAddress)
     MSG_IN(MessageType_MessageType_EthereumSignTx,                  EthereumSignTx,              fsm_msgEthereumSignTx)
     MSG_IN(MessageType_MessageType_EthereumTxAck,                   EthereumTxAck,               fsm_msgEthereumTxAck)
+    MSG_IN(MessageType_MessageType_EthereumTxMetadata,              EthereumTxMetadata,          fsm_msgEthereumTxMetadata)
     MSG_IN(MessageType_MessageType_EthereumSignMessage,             EthereumSignMessage,         fsm_msgEthereumSignMessage)
     MSG_IN(MessageType_MessageType_EthereumVerifyMessage,           EthereumVerifyMessage,       fsm_msgEthereumVerifyMessage)
 
@@ -118,6 +119,7 @@
     MSG_OUT(MessageType_MessageType_EthereumMessageSignature,       EthereumMessageSignature,    NO_PROCESS_FUNC)
 
     MSG_OUT(MessageType_MessageType_EthereumTypedDataSignature,     EthereumTypedDataSignature,  NO_PROCESS_FUNC)
+    MSG_OUT(MessageType_MessageType_EthereumMetadataAck,            EthereumMetadataAck,         NO_PROCESS_FUNC)
 
     MSG_OUT(MessageType_MessageType_NanoAddress,                    NanoAddress,                 NO_PROCESS_FUNC)
     MSG_OUT(MessageType_MessageType_NanoSignedTx,                   NanoSignedTx,                NO_PROCESS_FUNC)