compute address from path

app/src/apdu_handler.c

@@ -123,6 +123,13 @@ __Z_INLINE void handleSign(volatile uint32_t *flags, volatile uint32_t *tx, uint
         THROW(APDU_CODE_OK);
     }
 
+    // Get address for the received path
+    zxerr_t zxerr = crypto_get_change_address();
+    if (zxerr != zxerr_ok) {
+        *tx = 0;
+        THROW(APDU_CODE_DATA_INVALID);
+    }
+
     const char *error_msg = tx_parse();
     CHECK_APP_CANARY()
     if (error_msg != NULL) {

app/src/common/actions.h

@@ -71,3 +71,13 @@ __Z_INLINE void app_reply_error() {
     set_code(G_io_apdu_buffer, 0, APDU_CODE_DATA_INVALID);
     io_exchange(CHANNEL_APDU | IO_RETURN_AFTER_TX, 2);
 }
+
+__Z_INLINE zxerr_t app_get_address() {
+    zxerr_t err = crypto_get_address();
+
+    if (err != zxerr_ok) {
+        THROW(APDU_CODE_EXECUTION_ERROR);
+    }
+
+    return zxerr_ok;
+}

app/src/crypto.c

@@ -26,6 +26,7 @@
 #include "zxmacros.h"
 
 uint32_t hdPath[HDPATH_LEN_DEFAULT];
+uint8_t change_address[32];
 
 static zxerr_t computeKeys(keys_t *saplingKeys) {
     if (saplingKeys == NULL) {
@@ -179,3 +180,13 @@ zxerr_t crypto_fillKeys(uint8_t *buffer, uint16_t bufferLen, key_kind_e requeste
 
     return zxerr_ok;
 }
+
+zxerr_t crypto_get_change_address(void) {
+    if (change_address == NULL || sizeof(change_address) != KEY_LENGTH) {
+        return zxerr_unknown;
+    }
+
+    MEMZERO(change_address, sizeof(change_address));
+    CHECK_ZXERR(crypto_generateSaplingKeys(change_address, sizeof(change_address), PublicAddress));
+    return zxerr_ok;
+}

app/src/crypto.h

@@ -27,10 +27,11 @@ extern "C" {
 #include "zxerror.h"
 
 extern uint32_t hdPath[HDPATH_LEN_DEFAULT];
+extern uint8_t change_address[32];
 
 zxerr_t crypto_fillKeys(uint8_t *buffer, uint16_t bufferLen, key_kind_e requestedKey, uint16_t *cmdResponseLen);
 zxerr_t crypto_sign(const uint8_t publickeyRandomness[32], const uint8_t txnHash[32], uint8_t *output, uint16_t outputLen);
-
+zxerr_t crypto_get_change_address(void);
 #if defined(LEDGER_SPECIFIC)
 zxerr_t crypto_generateSaplingKeys(uint8_t *output, uint16_t outputLen, key_kind_e requestedKey);
 #endif

app/src/parser.c

@@ -114,10 +114,10 @@ parser_error_t parser_validate(parser_context_t *ctx) {
 parser_error_t parser_getNumItems(const parser_context_t *ctx, uint8_t *num_items) {
     UNUSED(ctx);
 
-    // Txversion + (owner + amount ) * output_with_valid_asset_id + (owner + amount + asset id) * output_with_raw_asset_id +
-    // fee + expiration
+    // Txversion + From + (owner + amount ) * output_with_valid_asset_id + (owner + amount + asset id) *
+    // output_with_raw_asset_id + fee + expiration
     *num_items =
-        1 + ((ctx->tx_obj->outputs.elements - ctx->tx_obj->n_raw_asset_id) * 2) + (ctx->tx_obj->n_raw_asset_id * 3) + 2;
+        2 + ((ctx->tx_obj->outputs.elements - ctx->tx_obj->n_raw_asset_id) * 2) + (ctx->tx_obj->n_raw_asset_id * 3) + 2;
 
     if (*num_items == 0) {
         return parser_unexpected_number_items;
@@ -154,18 +154,33 @@ parser_error_t parser_getItem(const parser_context_t *ctx, uint8_t displayIdx, c
     CHECK_ERROR(checkSanity(numItems, displayIdx));
     cleanOutput(outKey, outKeyLen, outVal, outValLen);
 
-    // Calculate total output elements
     uint8_t tmp_idx = displayIdx;
     uint8_t asset_id_idx = 0;
     bool known_asset_id = false;
+    char buf[70] = {0};
 
     if (displayIdx == 0) {
         snprintf(outKey, outKeyLen, "Tx Version");
         snprintf(outVal, outValLen, "V%d", (uint8_t)ctx->tx_obj->transactionVersion);
         return parser_ok;
     }
-    char buf[70] = {0};
-    tmp_idx -= 1;                  // Adjust for the transaction version
+
+    if (displayIdx == 1) {
+        snprintf(outKey, outKeyLen, "From");
+#if defined(LEDGER_SPECIFIC)
+        array_to_hexstr(buf, sizeof(buf), change_address, 32);
+        pageString(outVal, outValLen, buf, pageIdx, pageCount);
+#else
+        uint8_t test_change_address[32] = {0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+                                           0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+                                           0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa};
+        array_to_hexstr(buf, sizeof(buf), test_change_address, 32);
+        pageString(outVal, outValLen, buf, pageIdx, pageCount);
+#endif
+        return parser_ok;
+    }
+
+    tmp_idx -= 2;                  // Adjust for the transaction version
     cumulative_display_count = 0;  // Reset cumulative display count for fresh calculation
 
     for (out_idx = 1; out_idx <= ctx->tx_obj->outputs.elements; out_idx++) {