feat(common & core & legacy): Stellar, add support for StellarManageBuyOfferOp.

common/protob/messages-stellar.proto

@@ -76,6 +76,7 @@ message StellarSignTx {
  * @next StellarCreateAccountOp
  * @next StellarPathPaymentStrictReceiveOp
  * @next StellarManageSellOfferOp
+ * @next StellarManageBuyOfferOp
  * @next StellarCreatePassiveOfferOp
  * @next StellarSetOptionsOp
  * @next StellarChangeTrustOp
@@ -140,6 +141,21 @@ message StellarManageSellOfferOp {
     required uint64 offer_id = 7;                   // Offer ID for updating an existing offer
 }
 
+/**
+ * Request: ask device to confirm this operation type
+ * @next StellarTxOpRequest
+ * @next StellarSignedTx
+ */
+message StellarManageBuyOfferOp {
+    optional string source_account = 1;             // (optional) source account address
+    required StellarAsset selling_asset = 2;
+    required StellarAsset buying_asset = 3;
+    required sint64 amount = 4;
+    required uint32 price_n = 5;                    // Price numerator
+    required uint32 price_d = 6;                    // Price denominator
+    required uint64 offer_id = 7;                   // Offer ID for updating an existing offer
+}
+
 /**
  * Request: ask device to confirm this operation type
  * @next StellarTxOpRequest

common/protob/messages.proto

@@ -239,6 +239,7 @@ enum MessageType {
     // omitted: StellarInflationOp is not a supported operation, would be 219
     MessageType_StellarManageDataOp = 220 [(wire_in) = true];
     MessageType_StellarBumpSequenceOp = 221 [(wire_in) = true];
+    MessageType_StellarManageBuyOfferOp = 222 [(wire_in) = true];
     MessageType_StellarSignedTx = 230 [(wire_out) = true];
 
     // Cardano

common/tests/fixtures/stellar/sign_tx.json

@@ -335,6 +335,45 @@
         "signature": "y9xb8IgPpkjgFa87I9alTD0mVc6EUcJrD7erZVPVGLdDs7rjh7fVtLAJS7iin85Yle0AwnqqEADYAjVzHzz7Bg=="
       }
     },
+    {
+      "name": "StellarManageBuyOfferOp",
+      "parameters": {
+        "xdr": "AAAAAgAAAAAvIrnGLwi3dPPr5t1ufbk8PsLL3gJ5Vho9nFIluMMikgAAAGQAAAAAAAAD6AAAAAEAAAAAG4J3zQAAAABd5CqEAAAAAAAAAAEAAAAAAAAADAAAAAJBQkNERUZHSElKS0wAAAAAKYSWAsIOWDZfEjwS2HocpFUNEM0hsK4OGNROPlb9ahUAAAABWAAAAAAAAABwi6oxX35cFm2EtGS/s4/WJXj+OtJyJ+dsy7ehecRRIQAAAAAdzxaYAAAAAwAAAAQAAAAAAAAFOQAAAAAAAAAA",
+        "address_n": "m/44'/148'/0'",
+        "network_passphrase": "Test SDF Network ; September 2015",
+        "tx": {
+          "source_account": "GAXSFOOGF4ELO5HT5PTN23T5XE6D5QWL3YBHSVQ2HWOFEJNYYMRJENBV",
+          "fee": 100,
+          "sequence_number": 1000,
+          "timebounds_start": 461535181,
+          "timebounds_end": 1575234180,
+          "memo_type": "NONE"
+        },
+        "operations": [
+          {
+            "_message_type": "StellarManageBuyOfferOp",
+            "selling_asset": {
+              "type": "ALPHANUM12",
+              "code": "ABCDEFGHIJKL",
+              "issuer": "GAUYJFQCYIHFQNS7CI6BFWD2DSSFKDIQZUQ3BLQODDKE4PSW7VVBKENC"
+            },
+            "buying_asset": {
+              "type": "ALPHANUM4",
+              "code": "X",
+              "issuer": "GBYIXKRRL57FYFTNQS2GJP5TR7LCK6H6HLJHEJ7HNTF3PILZYRISDLNQ"
+            },
+            "amount": 500111000,
+            "price_n": 3,
+            "price_d": 4,
+            "offer_id": 1337
+          }
+        ]
+      },
+      "result": {
+        "public_key": "2f22b9c62f08b774f3ebe6dd6e7db93c3ec2cbde0279561a3d9c5225b8c32292",
+        "signature": "sDQuKEm7j6Lsuw+QUTrotSloZiF+8LrXsuoLCBadewWpArO8+qmMgonrG3bJfaZ4dYdD8WcpfP5LNLOfU+lDBA=="
+      }
+    },
     {
       "name": "StellarManageSellOfferOp",
       "parameters": {

core/.changelog.d/1838.added

@@ -0,0 +1 @@
+Stellar: add support for StellarManageBuyOfferOp.

core/src/apps/stellar/README.md

@@ -25,6 +25,7 @@ Stellar transaction is composed of one or more operations. We support all [opera
 - Create Account
 - Create Passive Offer
 - Manage Data
+- Manage Buy Offer
 - Manage Sell Offer
 - Path Payment Strict Receive
 - Payment

core/src/apps/stellar/consts.py

@@ -14,6 +14,7 @@ if False:
         StellarCreateAccountOp,
         StellarCreatePassiveOfferOp,
         StellarManageDataOp,
+        StellarManageBuyOfferOp,
         StellarManageSellOfferOp,
         StellarPathPaymentStrictReceiveOp,
         StellarPaymentOp,
@@ -28,6 +29,7 @@ if False:
         StellarCreateAccountOp,
         StellarCreatePassiveOfferOp,
         StellarManageDataOp,
+        StellarManageBuyOfferOp,
         StellarManageSellOfferOp,
         StellarPathPaymentStrictReceiveOp,
         StellarPaymentOp,
@@ -37,7 +39,7 @@ if False:
 
 TX_TYPE = b"\x00\x00\x00\x02"
 
-# source: https://github.com/stellar/go/blob/3d2c1defe73dbfed00146ebe0e8d7e07ce4bb1b6/xdr/Stellar-transaction.x#L16
+# source: https://github.com/stellar/go/blob/a1db2a6b1f/xdr/Stellar-transaction.x#L35
 # Inflation not supported see https://github.com/trezor/trezor-core/issues/202#issuecomment-393342089
 op_codes: dict[int, int] = {
     MessageType.StellarAccountMergeOp: 8,
@@ -47,6 +49,7 @@ op_codes: dict[int, int] = {
     MessageType.StellarCreateAccountOp: 0,
     MessageType.StellarCreatePassiveOfferOp: 4,
     MessageType.StellarManageDataOp: 10,
+    MessageType.StellarManageBuyOfferOp: 12,
     MessageType.StellarManageSellOfferOp: 3,
     MessageType.StellarPathPaymentStrictReceiveOp: 2,
     MessageType.StellarPaymentOp: 1,
@@ -61,6 +64,7 @@ op_wire_types = [
     MessageType.StellarCreateAccountOp,
     MessageType.StellarCreatePassiveOfferOp,
     MessageType.StellarManageDataOp,
+    MessageType.StellarManageBuyOfferOp,
     MessageType.StellarManageSellOfferOp,
     MessageType.StellarPathPaymentStrictReceiveOp,
     MessageType.StellarPaymentOp,

core/src/apps/stellar/operations/__init__.py

@@ -34,6 +34,9 @@ async def process_operation(
     elif serialize.StellarManageDataOp.is_type_of(op):
         await layout.confirm_manage_data_op(ctx, op)
         serialize.write_manage_data_op(w, op)
+    elif serialize.StellarManageBuyOfferOp.is_type_of(op):
+        await layout.confirm_manage_buy_offer_op(ctx, op)
+        serialize.write_manage_buy_offer_op(w, op)
     elif serialize.StellarManageSellOfferOp.is_type_of(op):
         await layout.confirm_manage_sell_offer_op(ctx, op)
         serialize.write_manage_sell_offer_op(w, op)

core/src/apps/stellar/operations/layout.py

@@ -7,6 +7,7 @@ from trezor.messages import (
     StellarChangeTrustOp,
     StellarCreateAccountOp,
     StellarCreatePassiveOfferOp,
+    StellarManageBuyOfferOp,
     StellarManageDataOp,
     StellarManageSellOfferOp,
     StellarPathPaymentStrictReceiveOp,
@@ -106,8 +107,20 @@ async def confirm_create_passive_offer_op(
     await _confirm_offer(ctx, text, op)
 
 
+async def confirm_manage_buy_offer_op(
+    ctx: Context, op: StellarManageBuyOfferOp
+) -> None:
+    await _confirm_manage_offer_op_common(ctx, op)
+
+
 async def confirm_manage_sell_offer_op(
     ctx: Context, op: StellarManageSellOfferOp
+) -> None:
+    await _confirm_manage_offer_op_common(ctx, op)
+
+
+async def _confirm_manage_offer_op_common(
+    ctx: Context, op: StellarManageBuyOfferOp | StellarManageSellOfferOp
 ) -> None:
     if op.offer_id == 0:
         text = "New Offer"
@@ -123,21 +136,37 @@ async def confirm_manage_sell_offer_op(
 async def _confirm_offer(
     ctx: Context,
     title: str,
-    op: StellarCreatePassiveOfferOp | StellarManageSellOfferOp,
+    op: StellarCreatePassiveOfferOp
+    | StellarManageSellOfferOp
+    | StellarManageBuyOfferOp,
 ) -> None:
-    await confirm_properties(
-        ctx,
-        "op_offer",
-        title=title,
-        props=(
-            ("Selling:", format_amount(op.amount, op.selling_asset)),
-            ("Buying:", format_asset(op.buying_asset)),
-            (
-                f"Price per {format_asset(op.buying_asset)}:",
-                str(op.price_n / op.price_d),
-            ),
-        ),
-    )
+    if StellarManageBuyOfferOp.is_type_of(op):
+        buying = ("Buying:", format_amount(op.amount, op.buying_asset))
+        selling = ("Selling:", format_asset(op.selling_asset))
+        price = (
+            f"Price per {format_asset(op.selling_asset)}:",
+            str(op.price_n / op.price_d),
+        )
+        await confirm_properties(
+            ctx,
+            "op_offer",
+            title=title,
+            props=(buying, selling, price),
+        )
+    else:
+        selling = ("Selling:", format_amount(op.amount, op.selling_asset))
+        buying = ("Buying:", format_asset(op.buying_asset))
+        price = (
+            f"Price per {format_asset(op.buying_asset)}:",
+            str(op.price_n / op.price_d),
+        )
+        await confirm_properties(
+            ctx,
+            "op_offer",
+            title=title,
+            props=(selling, buying, price),
+        )
+
     await confirm_asset_issuer(ctx, op.selling_asset)
     await confirm_asset_issuer(ctx, op.buying_asset)
 

core/src/apps/stellar/operations/serialize.py

@@ -7,6 +7,7 @@ from trezor.messages import (
     StellarChangeTrustOp,
     StellarCreateAccountOp,
     StellarCreatePassiveOfferOp,
+    StellarManageBuyOfferOp,
     StellarManageDataOp,
     StellarManageSellOfferOp,
     StellarPathPaymentStrictReceiveOp,
@@ -65,10 +66,20 @@ def write_manage_data_op(w: Writer, msg: StellarManageDataOp) -> None:
         writers.write_string(w, msg.value)
 
 
+def write_manage_buy_offer_op(w: Writer, msg: StellarManageBuyOfferOp) -> None:
+    _write_manage_offer_op_common(w, msg)
+
+
 def write_manage_sell_offer_op(w: Writer, msg: StellarManageSellOfferOp) -> None:
+    _write_manage_offer_op_common(w, msg)
+
+
+def _write_manage_offer_op_common(
+    w: Writer, msg: StellarManageSellOfferOp | StellarManageBuyOfferOp
+) -> None:
     _write_asset(w, msg.selling_asset)
     _write_asset(w, msg.buying_asset)
-    writers.write_uint64(w, msg.amount)  # amount to sell
+    writers.write_uint64(w, msg.amount)  # amount to sell / buy
     writers.write_uint32(w, msg.price_n)  # numerator
     writers.write_uint32(w, msg.price_d)  # denominator
     writers.write_uint64(w, msg.offer_id)

core/src/trezor/enums/MessageType.py

@@ -130,6 +130,7 @@ if not utils.BITCOIN_ONLY:
     StellarAccountMergeOp = 218
     StellarManageDataOp = 220
     StellarBumpSequenceOp = 221
+    StellarManageBuyOfferOp = 222
     StellarSignedTx = 230
     CardanoSignTx = 303
     CardanoGetPublicKey = 305

core/src/trezor/enums/__init__.py

@@ -135,6 +135,7 @@ if TYPE_CHECKING:
         StellarAccountMergeOp = 218
         StellarManageDataOp = 220
         StellarBumpSequenceOp = 221
+        StellarManageBuyOfferOp = 222
         StellarSignedTx = 230
         CardanoSignTx = 303
         CardanoGetPublicKey = 305

core/src/trezor/messages.py

@@ -4824,6 +4824,32 @@ if TYPE_CHECKING:
         def is_type_of(cls, msg: protobuf.MessageType) -> TypeGuard["StellarManageSellOfferOp"]:
             return isinstance(msg, cls)
 
+    class StellarManageBuyOfferOp(protobuf.MessageType):
+        source_account: "str | None"
+        selling_asset: "StellarAsset"
+        buying_asset: "StellarAsset"
+        amount: "int"
+        price_n: "int"
+        price_d: "int"
+        offer_id: "int"
+
+        def __init__(
+            self,
+            *,
+            selling_asset: "StellarAsset",
+            buying_asset: "StellarAsset",
+            amount: "int",
+            price_n: "int",
+            price_d: "int",
+            offer_id: "int",
+            source_account: "str | None" = None,
+        ) -> None:
+            pass
+
+        @classmethod
+        def is_type_of(cls, msg: protobuf.MessageType) -> TypeGuard["StellarManageBuyOfferOp"]:
+            return isinstance(msg, cls)
+
     class StellarCreatePassiveOfferOp(protobuf.MessageType):
         source_account: "str | None"
         selling_asset: "StellarAsset"

legacy/firmware/.changelog.d/1838.added

@@ -0,0 +1 @@
+Stellar: add support for StellarManageBuyOfferOp.

legacy/firmware/fsm.h

@@ -120,6 +120,7 @@ void fsm_msgStellarPaymentOp(const StellarPaymentOp *msg);
 void fsm_msgStellarCreateAccountOp(const StellarCreateAccountOp *msg);
 void fsm_msgStellarPathPaymentStrictReceiveOp(
     const StellarPathPaymentStrictReceiveOp *msg);
+void fsm_msgStellarManageBuyOfferOp(const StellarManageBuyOfferOp *msg);
 void fsm_msgStellarManageSellOfferOp(const StellarManageSellOfferOp *msg);
 void fsm_msgStellarCreatePassiveOfferOp(const StellarCreatePassiveOfferOp *msg);
 void fsm_msgStellarSetOptionsOp(const StellarSetOptionsOp *msg);

legacy/firmware/fsm_msg_stellar.h

@@ -128,6 +128,24 @@ void fsm_msgStellarPathPaymentStrictReceiveOp(
   }
 }
 
+void fsm_msgStellarManageBuyOfferOp(const StellarManageBuyOfferOp *msg) {
+  if (!stellar_confirmManageBuyOfferOp(msg)) return;
+
+  if (stellar_allOperationsConfirmed()) {
+    RESP_INIT(StellarSignedTx);
+
+    stellar_fillSignedTx(resp);
+    msg_write(MessageType_MessageType_StellarSignedTx, resp);
+    layoutHome();
+  }
+  // Request the next operation to sign
+  else {
+    RESP_INIT(StellarTxOpRequest);
+
+    msg_write(MessageType_MessageType_StellarTxOpRequest, resp);
+  }
+}
+
 void fsm_msgStellarManageSellOfferOp(const StellarManageSellOfferOp *msg) {
   if (!stellar_confirmManageSellOfferOp(msg)) return;
 

legacy/firmware/protob/messages-stellar.options

@@ -21,6 +21,7 @@ StellarPathPaymentStrictReceiveOp.source_account                     max_size:57
 StellarPathPaymentStrictReceiveOp.destination_account                max_size:57
 StellarPathPaymentStrictReceiveOp.paths                              max_count:5
 
+StellarManageBuyOfferOp.source_account                     max_size:57
 
 StellarManageSellOfferOp.source_account                     max_size:57
 

legacy/firmware/stellar.c

@@ -388,6 +388,93 @@ bool stellar_confirmPathPaymentStrictReceiveOp(
   return true;
 }
 
+bool stellar_confirmManageBuyOfferOp(const StellarManageBuyOfferOp *msg) {
+  if (!stellar_signing) return false;
+
+  if (!stellar_confirmSourceAccount(msg->has_source_account,
+                                    msg->source_account)) {
+    stellar_signingAbort(_("Source account error"));
+    return false;
+  }
+
+  // Hash: operation type
+  stellar_hashupdate_uint32(12);
+
+  // New Offer / Delete #123 / Update #123
+  char str_offer[32] = {0};
+  if (msg->offer_id == 0) {
+    strlcpy(str_offer, _("New Offer"), sizeof(str_offer));
+  } else {
+    char str_offer_id[20] = {0};
+    stellar_format_uint64(msg->offer_id, str_offer_id, sizeof(str_offer_id));
+
+    if (msg->amount == 0) {
+      strlcpy(str_offer, _("Delete #"), sizeof(str_offer));
+    } else {
+      strlcpy(str_offer, _("Update #"), sizeof(str_offer));
+    }
+
+    strlcat(str_offer, str_offer_id, sizeof(str_offer));
+  }
+
+  char str_buying[32] = {0};
+  char str_buying_amount[32] = {0};
+  char str_buying_asset[32] = {0};
+
+  stellar_format_asset(&(msg->buying_asset), str_buying_asset,
+                       sizeof(str_buying_asset));
+  stellar_format_stroops(msg->amount, str_buying_amount,
+                         sizeof(str_buying_amount));
+
+  /*
+   Buy 200
+   XLM (Native Asset)
+  */
+  strlcpy(str_buying, _("Buy "), sizeof(str_buying));
+  strlcat(str_buying, str_buying_amount, sizeof(str_buying));
+
+  char str_selling[32] = {0};
+  char str_selling_asset[32] = {0};
+  char str_price[32] = {0};
+
+  stellar_format_asset(&(msg->selling_asset), str_selling_asset,
+                       sizeof(str_selling_asset));
+  stellar_format_price(msg->price_n, msg->price_d, str_price,
+                       sizeof(str_price));
+
+  /*
+   For 0.675952 Per
+   USD (G12345678)
+   */
+  strlcpy(str_selling, _("For "), sizeof(str_selling));
+  strlcat(str_selling, str_price, sizeof(str_selling));
+  strlcat(str_selling, _(" Per"), sizeof(str_selling));
+
+  stellar_layoutTransactionDialog(str_offer, str_buying, str_buying_asset,
+                                  str_selling, str_selling_asset);
+  if (!protectButton(ButtonRequestType_ButtonRequest_ProtectCall, false)) {
+    stellar_signingAbort(_("User canceled"));
+    return false;
+  }
+
+  // Hash selling asset
+  stellar_hashupdate_asset(&(msg->selling_asset));
+  // buying asset
+  stellar_hashupdate_asset(&(msg->buying_asset));
+  // amount to buy (signed vs. unsigned doesn't matter wrt hashing)
+  stellar_hashupdate_uint64(msg->amount);
+  // numerator
+  stellar_hashupdate_uint32(msg->price_n);
+  // denominator
+  stellar_hashupdate_uint32(msg->price_d);
+  // offer ID
+  stellar_hashupdate_uint64(msg->offer_id);
+
+  // At this point, the operation is confirmed
+  stellar_activeTx.confirmed_operations++;
+  return true;
+}
+
 bool stellar_confirmManageSellOfferOp(const StellarManageSellOfferOp *msg) {
   if (!stellar_signing) return false;
 

legacy/firmware/stellar.h

@@ -61,6 +61,7 @@ bool stellar_confirmCreateAccountOp(const StellarCreateAccountOp *msg);
 bool stellar_confirmPaymentOp(const StellarPaymentOp *msg);
 bool stellar_confirmPathPaymentStrictReceiveOp(
     const StellarPathPaymentStrictReceiveOp *msg);
+bool stellar_confirmManageBuyOfferOp(const StellarManageBuyOfferOp *msg);
 bool stellar_confirmManageSellOfferOp(const StellarManageSellOfferOp *msg);
 bool stellar_confirmCreatePassiveOfferOp(
     const StellarCreatePassiveOfferOp *msg);

python/src/trezorlib/messages.py

@@ -156,6 +156,7 @@ class MessageType(IntEnum):
     StellarAccountMergeOp = 218
     StellarManageDataOp = 220
     StellarBumpSequenceOp = 221
+    StellarManageBuyOfferOp = 222
     StellarSignedTx = 230
     CardanoSignTx = 303
     CardanoGetPublicKey = 305
@@ -6388,6 +6389,38 @@ class StellarManageSellOfferOp(protobuf.MessageType):
         self.source_account = source_account
 
 
+class StellarManageBuyOfferOp(protobuf.MessageType):
+    MESSAGE_WIRE_TYPE = 222
+    FIELDS = {
+        1: protobuf.Field("source_account", "string", repeated=False, required=False),
+        2: protobuf.Field("selling_asset", "StellarAsset", repeated=False, required=True),
+        3: protobuf.Field("buying_asset", "StellarAsset", repeated=False, required=True),
+        4: protobuf.Field("amount", "sint64", repeated=False, required=True),
+        5: protobuf.Field("price_n", "uint32", repeated=False, required=True),
+        6: protobuf.Field("price_d", "uint32", repeated=False, required=True),
+        7: protobuf.Field("offer_id", "uint64", repeated=False, required=True),
+    }
+
+    def __init__(
+        self,
+        *,
+        selling_asset: "StellarAsset",
+        buying_asset: "StellarAsset",
+        amount: "int",
+        price_n: "int",
+        price_d: "int",
+        offer_id: "int",
+        source_account: Optional["str"] = None,
+    ) -> None:
+        self.selling_asset = selling_asset
+        self.buying_asset = buying_asset
+        self.amount = amount
+        self.price_n = price_n
+        self.price_d = price_d
+        self.offer_id = offer_id
+        self.source_account = source_account
+
+
 class StellarCreatePassiveOfferOp(protobuf.MessageType):
     MESSAGE_WIRE_TYPE = 214
     FIELDS = {

python/src/trezorlib/stellar.py

@@ -43,6 +43,7 @@ try:
         TrustLineEntryFlag,
         Price,
         Network,
+        ManageBuyOffer,
     )
     from stellar_sdk.xdr.signer_key_type import SignerKeyType
 
@@ -225,6 +226,17 @@ def _read_operation(op: "Operation"):
         return messages.StellarBumpSequenceOp(
             source_account=source_account, bump_to=op.bump_to
         )
+    if isinstance(op, ManageBuyOffer):
+        price = _read_price(op.price)
+        return messages.StellarManageBuyOfferOp(
+            source_account=source_account,
+            selling_asset=_read_asset(op.selling),
+            buying_asset=_read_asset(op.buying),
+            amount=_read_amount(op.amount),
+            price_n=price.n,
+            price_d=price.d,
+            offer_id=op.offer_id,
+        )
     raise ValueError(f"Unknown operation type: {op.__class__.__name__}")
 
 

python/tests/test_stellar.py

@@ -712,3 +712,73 @@ def test_bump_sequence():
     assert isinstance(operations[0], messages.StellarBumpSequenceOp)
     assert operations[0].source_account == operation_source
     assert operations[0].bump_to == bump_to
+
+
+def test_manage_buy_offer_new_offer():
+    tx = make_default_tx()
+    price = "0.5"
+    amount = "50.0111"
+    selling_code = "XLM"
+    selling_issuer = None
+    buying_code = "USD"
+    buying_issuer = "GCSJ7MFIIGIRMAS4R3VT5FIFIAOXNMGDI5HPYTWS5X7HH74FSJ6STSGF"
+    operation_source = "GAEB4MRKRCONK4J7MVQXAHTNDPAECUCCCNE7YC5CKM34U3OJ673A4D6V"
+
+    envelope = tx.append_manage_buy_offer_op(
+        selling_code=selling_code,
+        selling_issuer=selling_issuer,
+        buying_code=buying_code,
+        buying_issuer=buying_issuer,
+        amount=amount,
+        price=price,
+        source=operation_source,
+    ).build()
+
+    tx, operations = stellar.from_envelope(envelope)
+    assert len(operations) == 1
+    assert isinstance(operations[0], messages.StellarManageBuyOfferOp)
+    assert operations[0].source_account == operation_source
+    assert operations[0].selling_asset.type == messages.StellarAssetType.NATIVE
+    assert operations[0].buying_asset.type == messages.StellarAssetType.ALPHANUM4
+    assert operations[0].buying_asset.code == buying_code
+    assert operations[0].buying_asset.issuer == buying_issuer
+    assert operations[0].amount == 500111000
+    assert operations[0].price_n == 1
+    assert operations[0].price_d == 2
+    assert operations[0].offer_id == 0  # indicates a new offer
+
+
+def test_manage_buy_offer_update_offer():
+    tx = make_default_tx()
+    price = "0.5"
+    amount = "50.0111"
+    selling_code = "XLM"
+    selling_issuer = None
+    buying_code = "USD"
+    buying_issuer = "GCSJ7MFIIGIRMAS4R3VT5FIFIAOXNMGDI5HPYTWS5X7HH74FSJ6STSGF"
+    offer_id = 12345
+    operation_source = "GAEB4MRKRCONK4J7MVQXAHTNDPAECUCCCNE7YC5CKM34U3OJ673A4D6V"
+
+    envelope = tx.append_manage_buy_offer_op(
+        selling_code=selling_code,
+        selling_issuer=selling_issuer,
+        buying_code=buying_code,
+        buying_issuer=buying_issuer,
+        amount=amount,
+        price=price,
+        offer_id=offer_id,
+        source=operation_source,
+    ).build()
+
+    tx, operations = stellar.from_envelope(envelope)
+    assert len(operations) == 1
+    assert isinstance(operations[0], messages.StellarManageBuyOfferOp)
+    assert operations[0].source_account == operation_source
+    assert operations[0].selling_asset.type == messages.StellarAssetType.NATIVE
+    assert operations[0].buying_asset.type == messages.StellarAssetType.ALPHANUM4
+    assert operations[0].buying_asset.code == buying_code
+    assert operations[0].buying_asset.issuer == buying_issuer
+    assert operations[0].amount == 500111000
+    assert operations[0].price_n == 1
+    assert operations[0].price_d == 2
+    assert operations[0].offer_id == offer_id

tests/ui_tests/fixtures.json

@@ -846,6 +846,7 @@
 "test_stellar.py::test_sign_tx[StellarCreateAccountOp]": "2582717c25974d2b3ee156624b00375148ff7fd12eeea73625a7c367fa610373",
 "test_stellar.py::test_sign_tx[StellarCreatePassiveOfferOp]": "6b0f0d2b746f98e2c85006ea7e2d5c49cd9277662e47f223138ff418066791e3",
 "test_stellar.py::test_sign_tx[StellarManageDataOp]": "8fbec6547a8f9d1f002181db0cbe57fe86abef8d365b1c06fd14292cd0b068a7",
+"test_stellar.py::test_sign_tx[StellarManageBuyOfferOp]": "fc57e1ca8b65588aa16cc3524d6dc0f01e094ad5d16a6f7e739a69c101b554bc",
 "test_stellar.py::test_sign_tx[StellarManageSellOfferOp]": "6ed84765b2ed46711be0ed1219d91c27e927119d352f37b2baf8c6501186bbce",
 "test_stellar.py::test_sign_tx[StellarPathPaymentStrictReceiveOp]": "58f3bfaece0706bc172d6e6564b728ec0b7f8e2629d8c64dc60672786586076d",
 "test_stellar.py::test_sign_tx[StellarPaymentOp-asset12]": "1d8e9d5d65420a259f7e2deef1efaf0ce5be966a0f1e5b8e95b832f176f00de2",