feat (app): Add nested-segwit support

test nested-segwit digest for 1 inputs and 2 output transactions
test nested-segwit digest for 2 inputs and 2 output transactions

Author: rxbryan

apps/btc_family/btc_pub_key.c

@@ -204,7 +204,16 @@ static size_t btc_get_address(const uint8_t *seed,
     case NON_SEGWIT:
       hdnode_get_address(&node, g_btc_app->p2pkh_addr_ver, addr, 35);
       break;
-    // TODO: add support for taproot and segwit
+    case PURPOSE_SEGWIT:
+      ecdsa_get_address_segwit_p2sh(node.public_key,
+                                    g_btc_app->p2sh_addr_ver,
+                                    node.curve->hasher_pubkey,
+                                    node.curve->hasher_base58,
+                                    addr,
+                                    36);
+      break;
+
+    // TODO: add support for taproot
     default:
       break;
   }

apps/btc_family/btc_script.c

@@ -239,13 +239,25 @@ bool btc_check_script_address(const uint8_t *script,
 
   uint8_t digest[HASHER_DIGEST_LENGTH] = {0};
   btc_script_type_e type = btc_get_script_type(script, script_len);
-  if (SCRIPT_TYPE_P2PKH != type && SCRIPT_TYPE_P2WPKH != type) {
-    // allow only p2pkh and p2wpkh for change output
+  if (SCRIPT_TYPE_P2PKH != type && SCRIPT_TYPE_P2WPKH != type &&
+      SCRIPT_TYPE_P2SH != type) {
+    // allow only p2pkh and p2wpkh and p2sh-p2wpkh for change output
     return false;
   }
   uint8_t offset = (SCRIPT_TYPE_P2PKH == type) ? 3 : 2;
 
   hasher_Raw(HASHER_SHA2_RIPEMD, public_key, BTC_SHORT_PUB_KEY_SIZE, digest);
+
+  if (SCRIPT_TYPE_P2SH == type) {
+    // Compute redeemscript(P2WPKH). scriptpub of nested-segwit is hash160 of
+    // redeemscript
+    uint8_t buf[22] = {0};
+    buf[0] = 0;     // version byte
+    buf[1] = 20;    // push 20 bytes
+    memcpy(buf + 2, digest, 20);
+    hasher_Raw(HASHER_SHA2_RIPEMD, buf, 22, digest);
+  }
+
   return (memcmp(digest, &script[offset], RIPEMD160_DIGEST_LENGTH) == 0);
 }
 

apps/btc_family/btc_txn.c

@@ -478,7 +478,8 @@ static bool fetch_valid_input(btc_query_t *query) {
       return false;
     }
 
-    if ((SCRIPT_TYPE_P2PKH != type && SCRIPT_TYPE_P2WPKH != type) ||
+    if ((SCRIPT_TYPE_P2PKH != type && SCRIPT_TYPE_P2WPKH != type &&
+         SCRIPT_TYPE_P2SH != type) ||
         0 != status) {
       // input validation failed, terminate immediately
       btc_send_error(ERROR_COMMON_ERROR_CORRUPT_DATA_TAG,
@@ -648,11 +649,27 @@ static bool sign_input(scrip_sig_t *signatures) {
   status = true;
   for (int idx = 0; idx < btc_txn_context->metadata.input_count; idx++) {
     // generate the input digest and respective private key
-    status = btc_digest_input(btc_txn_context, idx, buffer);
     memcpy(&t_node, &node, sizeof(HDNode));
     hdnode_private_ckd(&t_node, btc_txn_context->inputs[idx].change_index);
     hdnode_private_ckd(&t_node, btc_txn_context->inputs[idx].address_index);
     hdnode_fill_public_key(&t_node);
+
+    // detect input type
+    btc_sign_txn_input_script_pub_key_t *script =
+        &btc_txn_context->inputs[idx].script_pub_key;
+    btc_script_type_e type = btc_get_script_type(script->bytes, script->size);
+    if (SCRIPT_TYPE_P2SH == type) {
+      // replace BIP16 scriptpubkey with redeemscript(P2WPKH)
+      uint8_t buf[22] = {0};
+      buf[0] = 0;     // version byte
+      buf[1] = 20;    // push 20 bytes
+      ecdsa_get_pubkeyhash(
+          t_node.public_key, t_node.curve->hasher_pubkey, buf + 2);
+      memcpy(btc_txn_context->inputs[idx].script_pub_key.bytes, buf, 22);
+      btc_txn_context->inputs[idx].script_pub_key.size = 22;
+    }
+
+    status = btc_digest_input(btc_txn_context, idx, buffer);
     ecdsa_sign_digest(
         curve, t_node.private_key, buffer, signatures[idx].bytes, NULL, NULL);
     signatures[idx].size = btc_sig_to_script_sig(

apps/btc_family/btc_txn_helpers.c

@@ -670,7 +670,6 @@ bool btc_digest_input(const btc_txn_context_t *context,
   btc_sign_txn_input_script_pub_key_t *script =
       &context->inputs[index].script_pub_key;
   btc_script_type_e type = btc_get_script_type(script->bytes, script->size);
-
   if (SCRIPT_TYPE_P2WPKH == type) {
     // segwit digest calculation; could fail if segwit_cache not filled
     status = calculate_p2wpkh_digest(context, index, digest);