Merge pull request #110 from LedgerHQ/j-berman-hf-v15

support for hf 15 (view tags)
LedgerHQ · Jul 27, 2022 · 31772fd · 31772fd
2 parents 440ed25 + 163e5d2
commit 31772fd
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diff --git a/.github/workflows/lint-workflow.yml b/.github/workflows/lint-workflow.yml
@@ -1,6 +1,14 @@
 name: Code style check
 
-on: [push, pull_request]
+on:
+  push:
+    branches:
+      - master
+      - develop
+  pull_request:
+    branches:
+      - master
+      - develop
 
 jobs:
   job_lint:

diff --git a/Makefile b/Makefile
@@ -39,8 +39,8 @@ endif
 #DEFINES += MONERO_BETA
 
 APPVERSION_M=1
-APPVERSION_N=7
-APPVERSION_P=8
+APPVERSION_N=8
+APPVERSION_P=0
 
 APPVERSION=$(APPVERSION_M).$(APPVERSION_N).$(APPVERSION_P)
 SPECVERSION="1.0"

diff --git a/doc/developer/blue-app-commands.rst b/doc/developer/blue-app-commands.rst
@@ -104,6 +104,8 @@
 .. |eDRVout| replace:: :math:`\widetilde{\mathfrak{D}_\mathrm{out}}`
 .. |AKout|  replace::  :math:`\mathcal{AK}_\mathrm{amount}`
 .. |eAKout| replace:: :math:`\widetilde{\mathcal{AK}_\mathrm{amount}}`
+.. |vtf|    replace:: :math:`\mathit{view_tag_full}`
+.. |vt|     replace:: :math:`\mathit{view_tag}`
 
 
 .. |ctH|       replace:: :math:`\mathcal{H}_\mathrm{commitment}`
@@ -198,6 +200,7 @@ To summarize, the signature process is:
 
        - compute the range proof
        - blind the amount
+       - compute the view tag
 
    . Compute the final confidential ring signature
 
@@ -1142,6 +1145,54 @@ return |Img|.
 +--------+-----------------------------------------------------------------+
 
 
+Derive View Tag
+~~~~~~~~~~~~~~~~~~
+
+**Monero**
+
+crypto::derive_view_tag.
+
+**Description**
+
+Derive the view tag of an output.
+
+    | compute  |Drv|  = |dec|[|spk|](|eDrv|)
+    | compute  |vtf|  = |Hs|("view_tag" \|, |Drv|, |idx|)
+    | compute  |vt|   = |vtf|[0:1]
+
+return |vt|.
+
+**Command**
+
++-----+-----+-----+-----+----------+
+| CLA | INS | P1  | P2  | LC       |
++=====+=====+=====+=====+==========+
+| 03  | 3B  | 00  | 00  | 25 or 45 |
++-----+-----+-----+-----+----------+
+
+**Command data**
+
++--------+-----------------------------------------------------------------+
+| Length |    Value                                                        |
++========+=================================================================+
+| 01     | 00                                                              |
++--------+-----------------------------------------------------------------+
+| 20     | encrypted key derivation |eDrv|                                 |
++--------+-----------------------------------------------------------------+
+| 20     | ephemeral hmac (optional, only during active transaction)       |
++--------+-----------------------------------------------------------------+
+| 04     | index                                                           |
++--------+-----------------------------------------------------------------+
+
+**Response data**
+
++--------+-----------------------------------------------------------------+
+| Length |    Value                                                        |
++========+=================================================================+
+| 01     | view tag |vt|                                                   |
++--------+-----------------------------------------------------------------+
+
+
 Generate Keypair
 ~~~~~~~~~~~~~~~~
 

diff --git a/src/monero_api.h b/src/monero_api.h
@@ -47,6 +47,7 @@ int monero_apdu_derivation_to_scalar(void);
 int monero_apdu_derive_public_key(void);
 int monero_apdu_derive_secret_key(void);
 int monero_apdu_generate_key_image(void);
+int monero_apdu_derive_view_tag(void);
 int monero_apdu_derive_subaddress_public_key(void);
 int monero_apdu_get_subaddress(void);
 int monero_apdu_get_subaddress_spend_public_key(void);
@@ -169,6 +170,7 @@ void monero_derive_public_key(unsigned char *x, unsigned char *drv_data, unsigne
                               unsigned char *ec_pub);
 void monero_secret_key_to_public_key(unsigned char *ec_pub, unsigned char *ec_priv);
 void monero_generate_key_image(unsigned char *img, unsigned char *P, unsigned char *x);
+void monero_derive_view_tag(unsigned char *view_tag, unsigned char *drv_data, unsigned int out_idx);
 
 void monero_derive_subaddress_public_key(unsigned char *x, unsigned char *pub,
                                          unsigned char *drv_data, unsigned int index);

diff --git a/src/monero_crypto.c b/src/monero_crypto.c
@@ -519,6 +519,22 @@ void monero_generate_key_image(unsigned char *img, unsigned char *P, unsigned ch
     monero_ecmul_k(img, I, x);
 }
 
+/* ----------------------------------------------------------------------- */
+/* ---                                                                 --- */
+/* ----------------------------------------------------------------------- */
+void monero_derive_view_tag(unsigned char *view_tag, unsigned char *drv_data,
+                            unsigned int out_idx) {
+    unsigned char varint[8 + 32 + 8];
+    unsigned int len_varint;
+
+    os_memmove(varint, "view_tag", 8);
+    os_memmove(varint + 8, drv_data, 32);
+    len_varint = monero_encode_varint(varint + 8 + 32, 8, out_idx);
+    len_varint += 8 + 32;
+    monero_keccak_F(varint, len_varint, varint);
+    os_memmove(view_tag, varint, 1);
+}
+
 /* ======================================================================= */
 /*                               SUB ADDRESS                               */
 /* ======================================================================= */

diff --git a/src/monero_dispatch.c b/src/monero_dispatch.c
@@ -84,6 +84,7 @@ int check_ins_access() {
         case INS_DERIVE_PUBLIC_KEY:
         case INS_DERIVE_SECRET_KEY:
         case INS_GEN_KEY_IMAGE:
+        case INS_DERIVE_VIEW_TAG:
         case INS_SECRET_KEY_TO_PUBLIC_KEY:
         case INS_SECRET_KEY_ADD:
         case INS_GENERATE_KEYPAIR:
@@ -188,6 +189,9 @@ int monero_dispatch() {
         case INS_GEN_KEY_IMAGE:
             sw = monero_apdu_generate_key_image();
             break;
+        case INS_DERIVE_VIEW_TAG:
+            sw = monero_apdu_derive_view_tag();
+            break;
         case INS_SECRET_KEY_ADD:
             sw = monero_apdu_sc_add();
             break;

diff --git a/src/monero_init.c b/src/monero_init.c
@@ -177,32 +177,45 @@ void monero_install(unsigned char netId) {
 /* ----------------------------------------------------------------------- */
 /* --- Reset                                                           --- */
 /* ----------------------------------------------------------------------- */
-const char* const monero_supported_client[] = {"0.17.0.", "0.17.1.", "0.17.2.", "0.17.3."};
-#define MONERO_SUPPORTED_CLIENT_SIZE \
-    (sizeof(monero_supported_client) / sizeof(monero_supported_client[0]))
+// Accept the following versions and their derivates
+const char* const supported_clients[] = {"0.18."};
+#define MONERO_SUPPORTED_CLIENT_SIZE (sizeof(supported_clients) / sizeof(supported_clients[0]))
+
+// Explicitly refuse the following versions
+const char* const refused_clients[] = {"0.18.0.0."};
+#define MONERO_REFUSED_CLIENT_SIZE (sizeof(refused_clients) / sizeof(refused_clients[0]))
+
+static bool is_client_version_valid(const char* client_version) {
+    // Check if version is explicitly refused
+    for (uint32_t i = 0; i < MONERO_REFUSED_CLIENT_SIZE; ++i) {
+        if (strcmp(PIC(refused_clients[i]), client_version) == 0) {
+            return false;
+        }
+    }
+    // Check if version is supported
+    for (uint32_t i = 0; i < MONERO_SUPPORTED_CLIENT_SIZE; ++i) {
+        // Use strncmp to allow supported version prefixing client version
+        unsigned int supported_clients_len = strlen(PIC(supported_clients[i]));
+        if (strncmp(PIC(supported_clients[i]), client_version, supported_clients_len) == 0) {
+            return true;
+        }
+    }
+    return false;
+}
 
 int monero_apdu_reset() {
     unsigned int client_version_len;
     char client_version[16];
+    memset(client_version, '\0', 16);
     client_version_len = G_monero_vstate.io_length - G_monero_vstate.io_offset;
     if (client_version_len > 14) {
         THROW(SW_CLIENT_NOT_SUPPORTED + 1);
     }
     monero_io_fetch((unsigned char*)&client_version[0], client_version_len);
+    // Add '.' suffix to avoid 'X.1' prefixing 'X.10'
     client_version[client_version_len] = '.';
-    client_version_len++;
-    client_version[client_version_len] = 0;
-    unsigned int i = 0;
-    while (i < MONERO_SUPPORTED_CLIENT_SIZE) {
-        unsigned int monero_supported_client_len = strlen((char*)PIC(monero_supported_client[i]));
-        if ((monero_supported_client_len <= client_version_len) &&
-            (os_memcmp((char*)PIC(monero_supported_client[i]), client_version,
-                       monero_supported_client_len) == 0)) {
-            break;
-        }
-        i++;
-    }
-    if (i == MONERO_SUPPORTED_CLIENT_SIZE) {
+
+    if (!is_client_version_valid(client_version)) {
         THROW(SW_CLIENT_NOT_SUPPORTED);
     }
 

diff --git a/src/monero_key.c b/src/monero_key.c
@@ -604,6 +604,27 @@ int monero_apdu_generate_key_image(
     return SW_OK;
 }
 
+/* ----------------------------------------------------------------------- */
+/* ---                                                                 --- */
+/* ----------------------------------------------------------------------- */
+int monero_apdu_derive_view_tag(
+    /*const crypto::key_derivation &derivation, const size_t output_index, crypto::view_tag &view_tag*/) {
+    unsigned char derivation[32];
+    unsigned int output_index;
+    unsigned char res[1];
+
+    // fetch
+    monero_io_fetch_decrypt(derivation, 32, TYPE_DERIVATION);
+    output_index = monero_io_fetch_u32();
+    monero_io_discard(0);
+
+    // derive and keep
+    monero_derive_view_tag(res, derivation, output_index);
+
+    monero_io_insert(res, 1);
+    return SW_OK;
+}
+
 /* ----------------------------------------------------------------------- */
 /* ---                                                                 --- */
 /* ----------------------------------------------------------------------- */
@@ -692,7 +713,7 @@ int monero_apdu_get_subaddress_secret_key(/*const crypto::secret_key& sec, const
 /* ---                                                                 --- */
 /* ----------------------------------------------------------------------- */
 
-int monero_apu_generate_txout_keys(/*size_t tx_version, crypto::secret_key tx_sec, crypto::public_key Aout, crypto::public_key Bout, size_t output_index, bool is_change, bool is_subaddress, bool need_additional_key*/) {
+int monero_apu_generate_txout_keys(/*size_t tx_version, crypto::secret_key tx_sec, crypto::public_key Aout, crypto::public_key Bout, size_t output_index, bool is_change, bool is_subaddress, bool need_additional_key, bool use_view_tags*/) {
     // IN
     unsigned int tx_version;
     unsigned char tx_key[32];
@@ -704,10 +725,12 @@ int monero_apu_generate_txout_keys(/*size_t tx_version, crypto::secret_key tx_se
     unsigned char is_subaddress;
     unsigned char need_additional_txkeys;
     unsigned char additional_txkey_sec[32];
+    unsigned char use_view_tags;
     // OUT
     unsigned char additional_txkey_pub[32];
 #define amount_key         tx_key
 #define out_eph_public_key additional_txkey_sec
+    unsigned char view_tag[1];
     // TMP
     unsigned char derivation[32];
 
@@ -728,6 +751,7 @@ int monero_apu_generate_txout_keys(/*size_t tx_version, crypto::secret_key tx_se
     } else {
         monero_io_fetch(NULL, 32);
     }
+    use_view_tags = monero_io_fetch_u8();
 
     // update outkeys hash control
     if (G_monero_vstate.tx_sig_mode == TRANSACTION_CREATE_REAL) {
@@ -769,13 +793,21 @@ int monero_apu_generate_txout_keys(/*size_t tx_version, crypto::secret_key tx_se
     // compute ephemeral output key
     monero_derive_public_key(out_eph_public_key, derivation, output_index, Bout);
 
+    // compute view tag
+    if (use_view_tags) {
+        monero_derive_view_tag(view_tag, derivation, output_index);
+    }
+
     // send all
     monero_io_discard(0);
     monero_io_insert_encrypt(amount_key, 32, TYPE_AMOUNT_KEY);
     monero_io_insert(out_eph_public_key, 32);
     if (need_additional_txkeys) {
         monero_io_insert(additional_txkey_pub, 32);
     }
+    if (use_view_tags) {
+        monero_io_insert(view_tag, 1);
+    }
     G_monero_vstate.tx_output_cnt++;
     return SW_OK;
 }
diff --git a/src/monero_types.h b/src/monero_types.h
@@ -252,6 +252,7 @@ typedef struct monero_v_state_s monero_v_state_t;
 #define INS_DERIVE_PUBLIC_KEY        0x36
 #define INS_DERIVE_SECRET_KEY        0x38
 #define INS_GEN_KEY_IMAGE            0x3A
+#define INS_DERIVE_VIEW_TAG          0x3B
 #define INS_SECRET_KEY_ADD           0x3C
 #define INS_GENERATE_KEYPAIR         0x40
 #define INS_SECRET_SCAL_MUL_KEY      0x42

diff --git a/tests/monero_client/monero_cmd.py b/tests/monero_client/monero_cmd.py
@@ -174,6 +174,7 @@ def gen_txout_keys(self,
             b"\x01" if is_change_addr else b"\x00",
             b"\x01" if is_subaddress else b"\x00",
             b"\x00" * 33,  # additional_txkeys
+            b"\x00" * 33,  # use_view_tags
         ))
 
         self.device.send(cla=PROTOCOL_VERSION,

diff --git a/tests/monero_client/monero_crypto_cmd.py b/tests/monero_client/monero_crypto_cmd.py
@@ -259,3 +259,27 @@ def gen_key_derivation(self, pub_key: bytes, _priv_key: bytes) -> bytes:
             assert len(response) == 32
 
         return _d_in
+
+    def derive_view_tag(self, derivation: bytes, output_index: bytes) -> int:
+        ins: InsType = InsType.INS_DERIVE_VIEW_TAG
+
+        payload: bytes = b"".join([
+            derivation,
+            output_index,
+        ])
+
+        self.device.send(cla=PROTOCOL_VERSION,
+                         ins=ins,
+                         p1=0,
+                         p2=0,
+                         option=0,
+                         payload=payload)
+
+        sw, response = self.device.recv()  # type: int, bytes
+
+        if not sw & 0x9000:
+            raise DeviceError(sw, ins)
+
+        assert len(response) == 1
+
+        return int.from_bytes(response, "big")
diff --git a/tests/monero_client/monero_types.py b/tests/monero_client/monero_types.py
@@ -45,6 +45,7 @@ class InsType(enum.IntEnum):
     INS_DERIVE_PUBLIC_KEY = 0x36
     INS_DERIVE_SECRET_KEY = 0x38
     INS_GEN_KEY_IMAGE = 0x3A
+    INS_DERIVE_VIEW_TAG = 0x3B
     INS_SECRET_KEY_ADD = 0x3C
     INS_GENERATE_KEYPAIR = 0x40
     INS_SECRET_SCAL_MUL_KEY = 0x42