hopefully better mac compiling

src/carrot_core/CMakeLists.txt

@@ -32,6 +32,7 @@ set(carrot_core_sources
   carrot_enote_scan.cpp
   core_types.cpp
   destination.cpp
+  device_ram_borrowed.cpp
   enote_utils.cpp
   hash_functions.cpp
   payment_proposal.cpp)

src/carrot_core/account_secrets.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2022, The Monero Project
+// Copyright (c) 2024, The Monero Project
 // 
 // All rights reserved.
 // 
@@ -51,7 +51,7 @@ void make_carrot_provespend_key(const crypto::secret_key &s_master,
 {
     // k_ps = H_n(s_m)
     const auto transcript = sp::make_fixed_transcript<CARROT_DOMAIN_SEP_PROVE_SPEND_KEY>();
-    derive_scalar(transcript.data(), transcript.size, &s_master, to_bytes(k_prove_spend_out));
+    derive_scalar(transcript.data(), transcript.size(), &s_master, to_bytes(k_prove_spend_out));
 }
 //-------------------------------------------------------------------------------------------------------------------
 void make_carrot_viewbalance_secret(const crypto::secret_key &s_master,
@@ -59,7 +59,7 @@ void make_carrot_viewbalance_secret(const crypto::secret_key &s_master,
 {
     // s_vb = H_32(s_m)
     const auto transcript = sp::make_fixed_transcript<CARROT_DOMAIN_SEP_VIEW_BALANCE_SECRET>();
-    derive_bytes_32(transcript.data(), transcript.size, &s_master, to_bytes(s_view_balance_out));
+    derive_bytes_32(transcript.data(), transcript.size(), &s_master, to_bytes(s_view_balance_out));
 }
 //-------------------------------------------------------------------------------------------------------------------
 void make_carrot_generateimage_key(const crypto::secret_key &s_view_balance,
@@ -67,7 +67,7 @@ void make_carrot_generateimage_key(const crypto::secret_key &s_view_balance,
 {
     // k_gi = H_n(s_vb)
     const auto transcript = sp::make_fixed_transcript<CARROT_DOMAIN_SEP_GENERATE_IMAGE_KEY>();
-    derive_scalar(transcript.data(), transcript.size, &s_view_balance, to_bytes(k_generate_image_out));
+    derive_scalar(transcript.data(), transcript.size(), &s_view_balance, to_bytes(k_generate_image_out));
 }
 //-------------------------------------------------------------------------------------------------------------------
 void make_carrot_viewincoming_key(const crypto::secret_key &s_view_balance,
@@ -75,7 +75,7 @@ void make_carrot_viewincoming_key(const crypto::secret_key &s_view_balance,
 {
     // k_v = H_n(s_vb)
     const auto transcript = sp::make_fixed_transcript<CARROT_DOMAIN_SEP_INCOMING_VIEW_KEY>();
-    derive_scalar(transcript.data(), transcript.size, &s_view_balance, to_bytes(k_view_out));
+    derive_scalar(transcript.data(), transcript.size(), &s_view_balance, to_bytes(k_view_out));
 }
 //-------------------------------------------------------------------------------------------------------------------
 void make_carrot_generateaddress_secret(const crypto::secret_key &s_view_balance,
@@ -83,7 +83,7 @@ void make_carrot_generateaddress_secret(const crypto::secret_key &s_view_balance
 {
     // s_ga = H_32(s_vb)
     const auto transcript = sp::make_fixed_transcript<CARROT_DOMAIN_SEP_GENERATE_ADDRESS_SECRET>();
-    derive_bytes_32(transcript.data(), transcript.size, &s_view_balance, to_bytes(s_generate_address_out));
+    derive_bytes_32(transcript.data(), transcript.size(), &s_view_balance, to_bytes(s_generate_address_out));
 }
 //-------------------------------------------------------------------------------------------------------------------
 void make_carrot_spend_pubkey(const crypto::secret_key &k_generate_image,

src/carrot_core/account_secrets.h

@@ -1,4 +1,4 @@
-// Copyright (c) 2022, The Monero Project
+// Copyright (c) 2024, The Monero Project
 // 
 // All rights reserved.
 // 

src/carrot_core/address_utils.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2022, The Monero Project
+// Copyright (c) 2024, The Monero Project
 // 
 // All rights reserved.
 // 
@@ -52,7 +52,7 @@ void make_carrot_index_extension_generator(const crypto::secret_key &s_generate_
 {
     // s^j_gen = H_32[s_ga](j_major, j_minor)
     const auto transcript = sp::make_fixed_transcript<CARROT_DOMAIN_SEP_ADDRESS_INDEX_GEN>(j_major, j_minor);
-    derive_bytes_32(transcript.data(), transcript.size, &s_generate_address, &address_generator_out);
+    derive_bytes_32(transcript.data(), transcript.size(), &s_generate_address, &address_generator_out);
 }
 //-------------------------------------------------------------------------------------------------------------------
 void make_carrot_subaddress_scalar(const crypto::public_key &spend_pubkey,
@@ -64,7 +64,7 @@ void make_carrot_subaddress_scalar(const crypto::public_key &spend_pubkey,
     // k^j_subscal = H_n(K_s, j_major, j_minor, s^j_gen)
     const auto transcript = sp::make_fixed_transcript<CARROT_DOMAIN_SEP_SUBADDRESS_SCALAR>(
         spend_pubkey, j_major, j_minor);
-    derive_scalar(transcript.data(), transcript.size, &s_address_generator, subaddress_scalar_out.data);
+    derive_scalar(transcript.data(), transcript.size(), &s_address_generator, subaddress_scalar_out.data);
 }
 //-------------------------------------------------------------------------------------------------------------------
 void make_carrot_address_spend_pubkey(const crypto::public_key &spend_pubkey,
@@ -82,20 +82,4 @@ void make_carrot_address_spend_pubkey(const crypto::public_key &spend_pubkey,
         rct::pk2rct(spend_pubkey), rct::sk2rct(subaddress_scalar)));
 }
 //-------------------------------------------------------------------------------------------------------------------
-void make_carrot_address(const crypto::public_key &spend_pubkey,
-    const crypto::secret_key &s_generate_address,
-    const std::uint32_t j_major,
-    const std::uint32_t j_minor,
-    const crypto::secret_key &k_view,
-    crypto::public_key &address_spend_pubkey_out)
-{
-    // K^j_s = k^j_subscal * K_s
-    crypto::public_key address_spend_pubkey;
-    make_carrot_address_spend_pubkey(spend_pubkey, s_generate_address, j_major, j_minor, address_spend_pubkey);
-
-    // K^j_v = k_v * K^j_s
-    address_spend_pubkey_out = rct::rct2pk(rct::scalarmultKey(
-        rct::pk2rct(address_spend_pubkey), rct::sk2rct(k_view)));
-}
-//-------------------------------------------------------------------------------------------------------------------
 } //namespace carrot

src/carrot_core/address_utils.h

@@ -1,4 +1,4 @@
-// Copyright (c) 2022, The Monero Project
+// Copyright (c) 2024, The Monero Project
 // 
 // All rights reserved.
 // 
@@ -92,22 +92,4 @@ void make_carrot_address_spend_pubkey(const crypto::public_key &spend_pubkey,
     const std::uint32_t j_minor,
     crypto::public_key &address_spend_pubkey_out);
 
-/**
-* brief: make_carrot_address - (K^j_s, K^j_v)
-*   K^j_s = k^j_subscal * K_s
-*   K^j_v = k_v K^j_s
-* param: spend_pubkey - K_s = k_gi G + k_ps U
-* param: s_generate_address - s_ga
-* param: j_major -
-* param: j_minor -
-* param: k_view - k_v
-* outparam: address_spend_pubkey_out - K^j_s
-*/
-void make_carrot_address(const crypto::public_key &spend_pubkey,
-    const crypto::secret_key &s_generate_address,
-    const std::uint32_t j_major,
-    const std::uint32_t j_minor,
-    const crypto::secret_key &k_view,
-    crypto::public_key &address_spend_pubkey_out);
-
 } //namespace carrot

src/carrot_core/carrot_enote_scan.cpp

@@ -32,6 +32,7 @@
 #include "carrot_enote_scan.h"
 
 //local headers
+#include "crypto/generators.h"
 #include "enote_utils.h"
 #include "ringct/rctOps.h"
 
@@ -44,10 +45,9 @@ namespace carrot
 {
 //-------------------------------------------------------------------------------------------------------------------
 //-------------------------------------------------------------------------------------------------------------------
-static bool try_scan_carrot_non_coinbase_no_janus(const CarrotEnoteV1 &enote,
+static bool try_scan_carrot_non_coinbase_core(const CarrotEnoteV1 &enote,
     const std::optional<encrypted_payment_id_t> encrypted_payment_id,
-    const input_context_t &input_context,
+    const crypto::hash &s_sender_receiver,
-    const unsigned char s_sender_receiver_unctx[32],
     crypto::secret_key &sender_extension_g_out,
     crypto::secret_key &sender_extension_t_out,
     crypto::public_key &address_spend_pubkey_out,
@@ -57,17 +57,6 @@ static bool try_scan_carrot_non_coinbase_no_janus(const CarrotEnoteV1 &enote,
     CarrotEnoteType &enote_type_out,
     janus_anchor_t &nominal_janus_anchor_out)
 {
-    // if vt' != vt, then FAIL
-    if (!test_carrot_view_tag(s_sender_receiver_unctx, input_context, enote.onetime_address, enote.view_tag))
-        return false;
-
-    // s^ctx_sr = H_32(s_sr, D_e, input_context)
-    crypto::hash s_sender_receiver;
-    make_carrot_sender_receiver_secret(s_sender_receiver_unctx,
-        enote.enote_ephemeral_pubkey,
-        input_context,
-        s_sender_receiver);
-
     // if cannot recompute C_a, then FAIL
     if (!try_get_carrot_amount(s_sender_receiver,
             enote.amount_enc,
@@ -109,9 +98,68 @@ static bool try_scan_carrot_non_coinbase_no_janus(const CarrotEnoteV1 &enote,
 }
 //-------------------------------------------------------------------------------------------------------------------
 //-------------------------------------------------------------------------------------------------------------------
+bool verify_carrot_janus_protection(const input_context_t &input_context,
+    const crypto::public_key &onetime_address,
+    const view_incoming_key_device &k_view_dev,
+    const crypto::public_key &account_spend_pubkey,
+    const crypto::public_key &nominal_address_spend_pubkey,
+    const crypto::x25519_pubkey &enote_ephemeral_pubkey,
+    const janus_anchor_t &nominal_anchor,
+    payment_id_t &nominal_payment_id_inout)
+{
+    const bool is_subaddress = nominal_address_spend_pubkey != account_spend_pubkey;
+
+    // make K^j_v'
+    crypto::public_key nominal_address_view_pubkey;
+    if (is_subaddress)
+    {
+        // K^j_v' = k_v K^j_s'
+        if (!k_view_dev.view_key_scalar_mult_ed25519(nominal_address_spend_pubkey, nominal_address_view_pubkey))
+            return false;
+    }
+    else // cryptonote address
+    {
+        // K^j_v' = k_v G
+        if (!k_view_dev.view_key_scalar_mult_ed25519(crypto::get_G(), nominal_address_view_pubkey))
+            return false;
+    }
+
+    // if can recompute D_e with pid', then PASS
+    if (verify_carrot_external_janus_protection(nominal_anchor,
+            input_context,
+            nominal_address_spend_pubkey, 
+            nominal_address_view_pubkey,
+            is_subaddress,
+            nominal_payment_id_inout,
+            enote_ephemeral_pubkey))
+        return true;
+
+    // if can recompute D_e with null pid, then PASS
+    nominal_payment_id_inout = null_payment_id;
+    if (verify_carrot_external_janus_protection(nominal_anchor,
+            input_context,
+            nominal_address_spend_pubkey, 
+            nominal_address_view_pubkey,
+            is_subaddress,
+            null_payment_id,
+            enote_ephemeral_pubkey))
+        return true;
+
+    // anchor_sp = H_16(D_e, input_context, Ko, k_v, K_s)
+    janus_anchor_t expected_special_anchor;
+    k_view_dev.make_janus_anchor_special(enote_ephemeral_pubkey,
+        input_context,
+        onetime_address,
+        account_spend_pubkey,
+        expected_special_anchor);
+
+    // attempt special janus check: anchor_sp ?= anchor'
+    return expected_special_anchor == nominal_anchor;
+}
+//-------------------------------------------------------------------------------------------------------------------
 bool try_scan_carrot_coinbase_enote(const CarrotCoinbaseEnoteV1 &enote,
     const crypto::x25519_pubkey &s_sender_receiver_unctx,
-    const crypto::secret_key &k_view,
+    const view_incoming_key_device &k_view_dev,
     const crypto::public_key &account_spend_pubkey,
     crypto::secret_key &sender_extension_g_out,
     crypto::secret_key &sender_extension_t_out,
@@ -166,7 +214,7 @@ bool try_scan_carrot_coinbase_enote(const CarrotCoinbaseEnoteV1 &enote,
     payment_id_t dummy_payment_id = null_payment_id;
     if (!verify_carrot_janus_protection(input_context,
             enote.onetime_address,
-            k_view,
+            k_view_dev,
             account_spend_pubkey,
             address_spend_pubkey_out,
             enote.enote_ephemeral_pubkey,
@@ -180,7 +228,7 @@ bool try_scan_carrot_coinbase_enote(const CarrotCoinbaseEnoteV1 &enote,
 bool try_scan_carrot_enote_external(const CarrotEnoteV1 &enote,
     const std::optional<encrypted_payment_id_t> encrypted_payment_id,
     const crypto::x25519_pubkey &s_sender_receiver_unctx,
-    const crypto::secret_key &k_view,
+    const view_incoming_key_device &k_view_dev,
     const crypto::public_key &account_spend_pubkey,
     crypto::secret_key &sender_extension_g_out,
     crypto::secret_key &sender_extension_t_out,
@@ -194,12 +242,22 @@ bool try_scan_carrot_enote_external(const CarrotEnoteV1 &enote,
     input_context_t input_context;
     make_carrot_input_context(enote.tx_first_key_image, input_context);
 
+    // test view tag
+    if (!test_carrot_view_tag(s_sender_receiver_unctx.data, input_context, enote.onetime_address, enote.view_tag))
+        return false;
+
+    // s^ctx_sr = H_32(s_sr, D_e, input_context)
+    crypto::hash s_sender_receiver;
+    make_carrot_sender_receiver_secret(s_sender_receiver_unctx.data,
+        enote.enote_ephemeral_pubkey,
+        input_context,
+        s_sender_receiver);
+
     // do core scanning
     janus_anchor_t nominal_anchor;
-    if (!try_scan_carrot_non_coinbase_no_janus(enote,
+    if (!try_scan_carrot_non_coinbase_core(enote,
             encrypted_payment_id,
-            input_context,
+            s_sender_receiver,
-            s_sender_receiver_unctx.data,
             sender_extension_g_out,
             sender_extension_t_out,
             address_spend_pubkey_out,
@@ -213,7 +271,7 @@ bool try_scan_carrot_enote_external(const CarrotEnoteV1 &enote,
     // verify Janus attack protection
     if (!verify_carrot_janus_protection(input_context,
             enote.onetime_address,
-            k_view,
+            k_view_dev,
             account_spend_pubkey,
             address_spend_pubkey_out,
             enote.enote_ephemeral_pubkey,
@@ -225,7 +283,7 @@ bool try_scan_carrot_enote_external(const CarrotEnoteV1 &enote,
 }
 //-------------------------------------------------------------------------------------------------------------------
 bool try_scan_carrot_enote_internal(const CarrotEnoteV1 &enote,
-    const crypto::secret_key &s_view_balance,
+    const view_balance_secret_device &s_view_balance_dev,
     crypto::secret_key &sender_extension_g_out,
     crypto::secret_key &sender_extension_t_out,
     crypto::public_key &address_spend_pubkey_out,
@@ -237,13 +295,26 @@ bool try_scan_carrot_enote_internal(const CarrotEnoteV1 &enote,
     input_context_t input_context;
     make_carrot_input_context(enote.tx_first_key_image, input_context);
 
+    // vt = H_3(s_sr || input_context || Ko)
+    view_tag_t nominal_view_tag;
+    s_view_balance_dev.make_internal_view_tag(input_context, enote.onetime_address, nominal_view_tag);
+
+    // test view tag
+    if (nominal_view_tag != enote.view_tag)
+        return false;
+
+    // s^ctx_sr = H_32(s_vb, D_e, input_context)
+    crypto::hash s_sender_receiver;
+    s_view_balance_dev.make_internal_sender_receiver_secret(enote.enote_ephemeral_pubkey,
+        input_context,
+        s_sender_receiver);
+
     // do core scanning
     janus_anchor_t nominal_anchor;
     payment_id_t dummy_payment_id;
-    if (!try_scan_carrot_non_coinbase_no_janus(enote,
+    if (!try_scan_carrot_non_coinbase_core(enote,
             std::nullopt,
-            input_context,
+            s_sender_receiver,
-            to_bytes(s_view_balance),
             sender_extension_g_out,
             sender_extension_t_out,
             address_spend_pubkey_out,

src/carrot_core/carrot_enote_scan.h

@@ -32,6 +32,7 @@
 
 //local headers
 #include "carrot_enote_types.h"
+#include "device.h"
 
 //third party headers
 
@@ -43,9 +44,18 @@
 
 namespace carrot
 {
+bool verify_carrot_janus_protection(const input_context_t &input_context,
+    const crypto::public_key &onetime_address,
+    const view_incoming_key_device &k_view_dev,
+    const crypto::public_key &account_spend_pubkey,
+    const crypto::public_key &nominal_address_spend_pubkey,
+    const crypto::x25519_pubkey &enote_ephemeral_pubkey,
+    const janus_anchor_t &nominal_anchor,
+    payment_id_t &nominal_payment_id_inout);
+
 bool try_scan_carrot_coinbase_enote(const CarrotCoinbaseEnoteV1 &enote,
     const crypto::x25519_pubkey &s_sender_receiver_unctx,
-    const crypto::secret_key &k_view,
+    const view_incoming_key_device &k_view_dev,
     const crypto::public_key &account_spend_pubkey,
     crypto::secret_key &sender_extension_g_out,
     crypto::secret_key &sender_extension_t_out,
@@ -54,7 +64,7 @@ bool try_scan_carrot_coinbase_enote(const CarrotCoinbaseEnoteV1 &enote,
 bool try_scan_carrot_enote_external(const CarrotEnoteV1 &enote,
     const std::optional<encrypted_payment_id_t> encrypted_payment_id,
     const crypto::x25519_pubkey &s_sender_receiver_unctx,
-    const crypto::secret_key &k_view,
+    const view_incoming_key_device &k_view_dev,
     const crypto::public_key &account_spend_pubkey,
     crypto::secret_key &sender_extension_g_out,
     crypto::secret_key &sender_extension_t_out,
@@ -65,7 +75,7 @@ bool try_scan_carrot_enote_external(const CarrotEnoteV1 &enote,
     CarrotEnoteType &enote_type_out);
 
 bool try_scan_carrot_enote_internal(const CarrotEnoteV1 &enote,
-    const crypto::secret_key &s_view_balance,
+    const view_balance_secret_device &s_view_balance_dev,
     crypto::secret_key &sender_extension_g_out,
     crypto::secret_key &sender_extension_t_out,
     crypto::public_key &address_spend_pubkey_out,

src/carrot_core/core_types.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2022, The Monero Project
+// Copyright (c) 2024, The Monero Project
 // 
 // All rights reserved.
 // 

src/carrot_core/core_types.h

@@ -1,4 +1,4 @@
-// Copyright (c) 2022, The Monero Project
+// Copyright (c) 2024, The Monero Project
 // 
 // All rights reserved.
 // 

src/carrot_core/destination.h

@@ -1,4 +1,4 @@
-// Copyright (c) 2022, The Monero Project
+// Copyright (c) 2024, The Monero Project
 // 
 // All rights reserved.
 // 

src/carrot_core/device.h

@@ -0,0 +1,165 @@
+// Copyright (c) 2024, The Monero Project
+// 
+// All rights reserved.
+// 
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+// 
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+// 
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+// 
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+// 
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//! @file Abstract interfaces for performing scanning without revealing account keys
+
+#pragma once
+
+//local headers
+#include "core_types.h"
+#include "crypto/crypto.h"
+#include "crypto/x25519.h"
+
+//third party headers
+
+//standard headers
+#include <cstdio>
+#include <stdexcept>
+#include <string>
+
+//forward declarations
+
+
+/**
+ * These device interfaces were written primarily to be as lean as possible, for ease of the
+ * implementor, so long as account keys don't leak. As such, the interfaces do not shield
+ * sender-receiver secrets, and thus temporary access to this device interface can expose
+ * transaction content permanently in a provable manner. The device interface currently used in
+ * Monero (hw::device) also exposes transaction content, which can be saved permanently, but it
+ * wouldn't necessarily be provable. Thus, in the case of a breach, the original user has some
+ * plausible deniability with (hw::device), which cannot be said of the interfaces in this file.
+ * It's not impossible to make carrot scanning happen completely on-device, but it is significantly
+ * more involved.
+ */
+
+namespace carrot
+{
+/**
+ * brief: base exception type for reporting carrot device errors.
+ * note: devices should only throw this exception or derived classes
+ */
+struct device_error: public std::runtime_error
+{
+    /**
+     * param: dev_make - e.g. "Trezor", "Ledger"
+     * param: dev_model - e.g. "Model T", "Nano X"
+     * param: func_called - verbatim device interface method name, e.g. "view_key_8_scalar_mult_x25519"
+     * param: msg - arbitrary error message
+     * param: code - arbitrary error code
+     */
+    device_error(std::string &&dev_make,
+            std::string &&dev_model,
+            std::string &&func_called,
+            std::string &&msg,
+            const int code)
+        : std::runtime_error(make_formatted_message(dev_make, dev_model, func_called, msg, code)), 
+            dev_make(dev_make), dev_model(dev_model), func_called(func_called), msg(msg), code(code)
+    {}
+
+    static std::string make_formatted_message(const std::string &dev_make,
+        const std::string &dev_model,
+        const std::string &func_called,
+        const std::string &msg,
+        const int code)
+    {
+        char buf[384];
+        snprintf(buf, sizeof(buf),
+            "%s %s device error (%d), at %s(): %s",
+            dev_make.c_str(), dev_model.c_str(), code, func_called.c_str(), msg.c_str());
+        return {buf};
+    }
+
+    const std::string dev_make;
+    const std::string dev_model; 
+    const std::string func_called;
+    const std::string msg;
+    const int code;
+};
+
+struct view_incoming_key_device
+{
+    /**
+     * brief: view_key_scalar_mult_ed25519 - do an Ed25519 scalar mult against the incoming view key
+     * param: P - Ed25519 base point
+     * outparam: kvP = k_v P
+     * return: true on success, false on failure (e.g. unable to decompress point)
+     */
+    virtual bool view_key_scalar_mult_ed25519(const crypto::public_key &P,
+        crypto::public_key &kvP) const = 0;
+
+    /**
+     * brief: view_key_8_scalar_mult_x25519 - do an X25519 scalar mult and cofactor clear against the incoming view key
+     * param: D - X25519 base point
+     * outparam: kv8D = 8 k_v D
+     * return: true on success, false on failure (e.g. unable to decompress point)
+     */
+    virtual bool view_key_8_scalar_mult_x25519(const crypto::x25519_pubkey &D,
+        crypto::x25519_pubkey &kv8D) const = 0;
+
+    /**
+     * brief: make_janus_anchor_special - make a janus anchor for "special" enotes
+     * param: enote_ephemeral_pubkey - D_e
+     * param: input_context - input_context
+     * param: account_spend_pubkey - K_s
+     * outparam: anchor_special_out - anchor_sp = anchor_sp = H_16(D_e, input_context, Ko, k_v, K_s)
+     */
+    virtual void make_janus_anchor_special(const crypto::x25519_pubkey &enote_ephemeral_pubkey,
+        const input_context_t &input_context,
+        const crypto::public_key &onetime_address,
+        const crypto::public_key &account_spend_pubkey,
+        janus_anchor_t &anchor_special_out) const = 0;
+
+    virtual ~view_incoming_key_device() = default;
+};
+
+struct view_balance_secret_device
+{
+    /**
+     * brief: make_internal_view_tag - make an internal view tag, given non-secret data
+     * param: input_context - input_context
+     * param: onetime_address - Ko
+     * outparam: view_tag_out - vt = H_3(s_vb || input_context || Ko)
+     */
+    virtual void make_internal_view_tag(const input_context_t &input_context,
+        const crypto::public_key &onetime_address,
+        view_tag_t &view_tag_out) const = 0;
+
+    /**
+     * brief: make_internal_sender_receiver_secret - make internal sender-receiver secret, given non-secret data
+     * param: enote_ephemeral_pubkey - D_e
+     * param: input_context - input_context
+     * outparam: s_sender_receiver_out - s_sr = s^ctx_sr = H_32(s_sr, D_e, input_context)
+     */
+    virtual void make_internal_sender_receiver_secret(const crypto::x25519_pubkey &enote_ephemeral_pubkey,
+        const input_context_t &input_context,
+        crypto::hash &s_sender_receiver_out) const = 0;
+
+    virtual ~view_balance_secret_device() = default;
+};
+
+} //namespace carrot

src/carrot_core/device_ram_borrowed.cpp

@@ -0,0 +1,90 @@
+// Copyright (c) 2024, The Monero Project
+// 
+// All rights reserved.
+// 
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+// 
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+// 
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+// 
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+// 
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//pair header
+#include "device_ram_borrowed.h"
+
+//local headers
+#include "enote_utils.h"
+#include "ringct/rctOps.h"
+
+//third party headers
+
+//standard headers
+
+
+namespace carrot
+{
+//-------------------------------------------------------------------------------------------------------------------
+bool view_incoming_key_ram_borrowed_device::view_key_scalar_mult_ed25519(const crypto::public_key &P,
+    crypto::public_key &kvP) const
+{
+    kvP = rct::rct2pk(rct::scalarmultKey(rct::pk2rct(P), rct::sk2rct(m_k_view_incoming)));
+    return true;
+}
+//-------------------------------------------------------------------------------------------------------------------
+bool view_incoming_key_ram_borrowed_device::view_key_8_scalar_mult_x25519(const crypto::x25519_pubkey &D,
+    crypto::x25519_pubkey &kv8D) const
+{
+    return make_carrot_uncontextualized_shared_key_receiver(m_k_view_incoming, D, kv8D);
+}
+//-------------------------------------------------------------------------------------------------------------------
+void view_incoming_key_ram_borrowed_device::make_janus_anchor_special(
+    const crypto::x25519_pubkey &enote_ephemeral_pubkey,
+    const input_context_t &input_context,
+    const crypto::public_key &onetime_address,
+    const crypto::public_key &account_spend_pubkey,
+    janus_anchor_t &anchor_special_out) const
+{
+    return make_carrot_janus_anchor_special(enote_ephemeral_pubkey,
+        input_context,
+        onetime_address,
+        m_k_view_incoming,
+        account_spend_pubkey,
+        anchor_special_out);
+}
+//-------------------------------------------------------------------------------------------------------------------
+void view_balance_secret_ram_borrowed_device::make_internal_view_tag(const input_context_t &input_context,
+    const crypto::public_key &onetime_address,
+    view_tag_t &view_tag_out) const
+{
+    make_carrot_view_tag(to_bytes(m_s_view_balance), input_context, onetime_address, view_tag_out);
+}
+//-------------------------------------------------------------------------------------------------------------------
+void view_balance_secret_ram_borrowed_device::make_internal_sender_receiver_secret(
+    const crypto::x25519_pubkey &enote_ephemeral_pubkey,
+    const input_context_t &input_context,
+    crypto::hash &s_sender_receiver_out) const
+{
+    make_carrot_sender_receiver_secret(to_bytes(m_s_view_balance),
+        enote_ephemeral_pubkey,
+        input_context,
+        s_sender_receiver_out);
+}
+//-------------------------------------------------------------------------------------------------------------------
+} //namespace carrot

src/carrot_core/device_ram_borrowed.h

@@ -0,0 +1,86 @@
+// Copyright (c) 2024, The Monero Project
+// 
+// All rights reserved.
+// 
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+// 
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+// 
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+// 
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+// 
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//! @file Carrot device implementations for in-memory keys & secrets
+
+#pragma once
+
+//local headers
+#include "device.h"
+
+//third party headers
+
+//standard headers
+
+//forward declarations
+
+
+namespace carrot
+{
+
+class view_incoming_key_ram_borrowed_device: public view_incoming_key_device
+{
+public:
+    view_incoming_key_ram_borrowed_device(const crypto::secret_key &k_view_incoming):
+        m_k_view_incoming(k_view_incoming) {}
+
+    bool view_key_scalar_mult_ed25519(const crypto::public_key &P,
+        crypto::public_key &kvP) const override;
+
+    bool view_key_8_scalar_mult_x25519(const crypto::x25519_pubkey &D,
+        crypto::x25519_pubkey &kv8D) const override;
+
+    void make_janus_anchor_special(const crypto::x25519_pubkey &enote_ephemeral_pubkey,
+        const input_context_t &input_context,
+        const crypto::public_key &onetime_address,
+        const crypto::public_key &account_spend_pubkey,
+        janus_anchor_t &anchor_special_out) const override;
+
+private:
+    const crypto::secret_key &m_k_view_incoming;
+};
+
+class view_balance_secret_ram_borrowed_device: public view_balance_secret_device
+{
+public:
+    view_balance_secret_ram_borrowed_device(const crypto::secret_key &s_view_balance):
+        m_s_view_balance(s_view_balance) {}
+
+    void make_internal_view_tag(const input_context_t &input_context,
+        const crypto::public_key &onetime_address,
+        view_tag_t &view_tag_out) const override;
+
+    void make_internal_sender_receiver_secret(const crypto::x25519_pubkey &enote_ephemeral_pubkey,
+        const input_context_t &input_context,
+        crypto::hash &s_sender_receiver_out) const override;
+
+private:
+    const crypto::secret_key &m_s_view_balance;
+};
+
+} //namespace carrot

src/carrot_core/enote_utils.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2022, The Monero Project
+// Copyright (c) 2024, The Monero Project
 // 
 // All rights reserved.
 // 
@@ -88,7 +88,7 @@ void make_carrot_enote_ephemeral_privkey(const janus_anchor_t &anchor_norm,
     // k_e = (H_64(anchor_norm, input_context, K^j_s, K^j_v, pid)) mod l
     const auto transcript = sp::make_fixed_transcript<CARROT_DOMAIN_SEP_EPHEMERAL_PRIVKEY>(
         anchor_norm, input_context, address_spend_pubkey, address_view_pubkey, payment_id);
-    derive_scalar(transcript.data(), transcript.size, nullptr, &enote_ephemeral_privkey_out);
+    derive_scalar(transcript.data(), transcript.size(), nullptr, &enote_ephemeral_privkey_out);
 }
 //-------------------------------------------------------------------------------------------------------------------
 void make_carrot_enote_ephemeral_pubkey_cryptonote(const crypto::secret_key &enote_ephemeral_privkey,
@@ -163,7 +163,7 @@ void make_carrot_view_tag(const unsigned char s_sender_receiver_unctx[32],
 {
     // vt = H_3(s_sr || input_context || Ko)
     const auto transcript = sp::make_fixed_transcript<CARROT_DOMAIN_SEP_VIEW_TAG>(input_context, onetime_address);
-    derive_bytes_3(transcript.data(), transcript.size, s_sender_receiver_unctx, &view_tag_out);
+    derive_bytes_3(transcript.data(), transcript.size(), s_sender_receiver_unctx, &view_tag_out);
 }
 //-------------------------------------------------------------------------------------------------------------------
 void make_carrot_input_context_coinbase(const std::uint64_t block_index, input_context_t &input_context_out)
@@ -189,7 +189,7 @@ void make_carrot_sender_receiver_secret(const unsigned char s_sender_receiver_un
     // s^ctx_sr = H_32(s_sr, D_e, input_context)
     const auto transcript = sp::make_fixed_transcript<CARROT_DOMAIN_SEP_SENDER_RECEIVER_SECRET>(
         enote_ephemeral_pubkey, input_context);
-    derive_bytes_32(transcript.data(), transcript.size, s_sender_receiver_unctx, &s_sender_receiver_out);
+    derive_bytes_32(transcript.data(), transcript.size(), s_sender_receiver_unctx, &s_sender_receiver_out);
 }
 //-------------------------------------------------------------------------------------------------------------------
 void make_carrot_onetime_address_extension_g(const crypto::hash &s_sender_receiver,
@@ -198,7 +198,7 @@ void make_carrot_onetime_address_extension_g(const crypto::hash &s_sender_receiv
 {
     // k^o_g = H_n("..g..", s^ctx_sr, C_a)
     const auto transcript = sp::make_fixed_transcript<CARROT_DOMAIN_SEP_ONETIME_EXTENSION_G>(amount_commitment);
-    derive_scalar(transcript.data(), transcript.size, &s_sender_receiver, &sender_extension_out);
+    derive_scalar(transcript.data(), transcript.size(), &s_sender_receiver, &sender_extension_out);
 }
 //-------------------------------------------------------------------------------------------------------------------
 void make_carrot_onetime_address_extension_t(const crypto::hash &s_sender_receiver,
@@ -207,7 +207,7 @@ void make_carrot_onetime_address_extension_t(const crypto::hash &s_sender_receiv
 {
     // k^o_t = H_n("..t..", s^ctx_sr, C_a)
     const auto transcript = sp::make_fixed_transcript<CARROT_DOMAIN_SEP_ONETIME_EXTENSION_T>(amount_commitment);
-    derive_scalar(transcript.data(), transcript.size, &s_sender_receiver, &sender_extension_out);
+    derive_scalar(transcript.data(), transcript.size(), &s_sender_receiver, &sender_extension_out);
 }
 //-------------------------------------------------------------------------------------------------------------------
 void make_carrot_onetime_address_extension_pubkey(const crypto::hash &s_sender_receiver,
@@ -253,7 +253,7 @@ void make_carrot_amount_blinding_factor(const crypto::hash &s_sender_receiver,
     // k_a = H_n(s^ctx_sr, enote_type)
     const auto transcript = sp::make_fixed_transcript<CARROT_DOMAIN_SEP_AMOUNT_BLINDING_FACTOR>(
         static_cast<unsigned char>(enote_type));
-    derive_scalar(transcript.data(), transcript.size, &s_sender_receiver, &amount_blinding_factor_out);
+    derive_scalar(transcript.data(), transcript.size(), &s_sender_receiver, &amount_blinding_factor_out);
 }
 //-------------------------------------------------------------------------------------------------------------------
 void make_carrot_anchor_encryption_mask(const crypto::hash &s_sender_receiver,
@@ -262,7 +262,7 @@ void make_carrot_anchor_encryption_mask(const crypto::hash &s_sender_receiver,
 {
     // m_anchor = H_16(s^ctx_sr, Ko)
     const auto transcript = sp::make_fixed_transcript<CARROT_DOMAIN_SEP_ENCRYPTION_MASK_ANCHOR>(onetime_address);
-    derive_bytes_16(transcript.data(), transcript.size, &s_sender_receiver, &anchor_encryption_mask_out);
+    derive_bytes_16(transcript.data(), transcript.size(), &s_sender_receiver, &anchor_encryption_mask_out);
 }
 //-------------------------------------------------------------------------------------------------------------------
 encrypted_janus_anchor_t encrypt_carrot_anchor(const janus_anchor_t &anchor,
@@ -295,7 +295,7 @@ void make_carrot_amount_encryption_mask(const crypto::hash &s_sender_receiver,
 {
     // m_a = H_8(s^ctx_sr, Ko)
     const auto transcript = sp::make_fixed_transcript<CARROT_DOMAIN_SEP_ENCRYPTION_MASK_AMOUNT>(onetime_address);
-    derive_bytes_8(transcript.data(), transcript.size, &s_sender_receiver, &amount_encryption_mask_out);
+    derive_bytes_8(transcript.data(), transcript.size(), &s_sender_receiver, &amount_encryption_mask_out);
 }
 //-------------------------------------------------------------------------------------------------------------------
 encrypted_amount_t encrypt_carrot_amount(const rct::xmr_amount amount,
@@ -328,7 +328,7 @@ void make_carrot_payment_id_encryption_mask(const crypto::hash &s_sender_receive
 {
     // m_pid = H_8(s^ctx_sr, Ko)
     const auto transcript = sp::make_fixed_transcript<CARROT_DOMAIN_SEP_ENCRYPTION_MASK_PAYMENT_ID>(onetime_address);
-    derive_bytes_8(transcript.data(), transcript.size, &s_sender_receiver, &payment_id_encryption_mask_out);
+    derive_bytes_8(transcript.data(), transcript.size(), &s_sender_receiver, &payment_id_encryption_mask_out);
 }
 //-------------------------------------------------------------------------------------------------------------------
 encrypted_payment_id_t encrypt_legacy_payment_id(const payment_id_t payment_id,
@@ -365,7 +365,7 @@ void make_carrot_janus_anchor_special(const crypto::x25519_pubkey &enote_ephemer
     // anchor_sp = H_16(D_e, input_context, Ko, k_v, K_s)
     const auto transcript = sp::make_fixed_transcript<CARROT_DOMAIN_SEP_JANUS_ANCHOR_SPECIAL>(
         enote_ephemeral_pubkey, input_context, account_spend_pubkey);
-    derive_bytes_16(transcript.data(), transcript.size, &k_view, &anchor_special_out);
+    derive_bytes_16(transcript.data(), transcript.size(), &k_view, &anchor_special_out);
 }
 //-------------------------------------------------------------------------------------------------------------------
 void recover_address_spend_pubkey(const crypto::public_key &onetime_address,
@@ -449,7 +449,7 @@ bool try_get_carrot_amount(const crypto::hash &s_sender_receiver,
     return false;
 }
 //-------------------------------------------------------------------------------------------------------------------
-bool verify_external_carrot_janus_protection(const janus_anchor_t &nominal_anchor,
+bool verify_carrot_external_janus_protection(const janus_anchor_t &nominal_anchor,
     const input_context_t &input_context,
     const crypto::public_key &nominal_address_spend_pubkey,
     const crypto::public_key &nominal_address_view_pubkey,
@@ -480,102 +480,4 @@ bool verify_external_carrot_janus_protection(const janus_anchor_t &nominal_ancho
     return nominal_enote_ephemeral_pubkey == enote_ephemeral_pubkey;
 }
 //-------------------------------------------------------------------------------------------------------------------
-bool verify_external_carrot_janus_protection_receiver(const janus_anchor_t &nominal_anchor,
-    const input_context_t &input_context,
-    const crypto::public_key &nominal_address_spend_pubkey,
-    const crypto::public_key &account_spend_pubkey,
-    const crypto::secret_key &k_view,
-    const crypto::x25519_pubkey &enote_ephemeral_pubkey,
-    payment_id_t &nominal_payment_id_inout)
-{
-    const bool is_subaddress = nominal_address_spend_pubkey != account_spend_pubkey;
-
-    // make K^j_v', given K^j_s'
-    crypto::public_key nominal_address_view_pubkey;
-    if (is_subaddress)
-        nominal_address_view_pubkey = rct::rct2pk(rct::scalarmultKey(rct::pk2rct(nominal_address_spend_pubkey),
-            rct::sk2rct(k_view)));
-    else // cryptonote address
-        nominal_address_view_pubkey = rct::rct2pk(rct::scalarmultBase(rct::sk2rct(k_view)));
-
-    // if can recompute D_e with pid', then PASS
-    if (verify_external_carrot_janus_protection(nominal_anchor,
-            input_context,
-            nominal_address_spend_pubkey, 
-            nominal_address_view_pubkey,
-            is_subaddress,
-            nominal_payment_id_inout,
-            enote_ephemeral_pubkey))
-        return true;
-
-    // if can recompute D_e with null pid, then PASS
-    nominal_payment_id_inout = null_payment_id;
-    if (verify_external_carrot_janus_protection(nominal_anchor,
-            input_context,
-            nominal_address_spend_pubkey, 
-            nominal_address_view_pubkey,
-            is_subaddress,
-            null_payment_id,
-            enote_ephemeral_pubkey))
-        return true;
-
-    // neither D_e recompute attempt passed, so FAIL
-    return false;
-}
-//-------------------------------------------------------------------------------------------------------------------
-bool verify_special_carrot_janus_protection(const crypto::x25519_pubkey &enote_ephemeral_pubkey,
-    const input_context_t &input_context,
-    const crypto::public_key &onetime_address,
-    const crypto::secret_key &k_view,
-    const crypto::public_key &account_spend_pubkey,
-    const janus_anchor_t &nominal_anchor)
-{
-    // anchor_sp' = H_16(D_e, input_context, Ko, k_v, K_s)
-    janus_anchor_t nominal_special_anchor;
-    make_carrot_janus_anchor_special(enote_ephemeral_pubkey,
-        input_context,
-        onetime_address,
-        k_view,
-        account_spend_pubkey,
-        nominal_special_anchor);
-    
-    // anchor_sp' ?= anchor'
-    return nominal_special_anchor == nominal_anchor;
-}
-//-------------------------------------------------------------------------------------------------------------------
-bool verify_carrot_janus_protection(const input_context_t &input_context,
-    const crypto::public_key &onetime_address,
-    const crypto::secret_key &k_view,
-    const crypto::public_key &account_spend_pubkey,
-    const crypto::public_key &nominal_address_spend_pubkey,
-    const crypto::x25519_pubkey &enote_ephemeral_pubkey,
-    const janus_anchor_t &nominal_anchor,
-    payment_id_t &nominal_payment_id_inout)
-{
-    // try checking for Janus protection, normal external path
-    if (verify_external_carrot_janus_protection_receiver(nominal_anchor,
-            input_context,
-            nominal_address_spend_pubkey,
-            account_spend_pubkey,
-            k_view,
-            enote_ephemeral_pubkey,
-            nominal_payment_id_inout))
-        return true;
-
-    // pid is always null for self-send enotes
-    nominal_payment_id_inout = null_payment_id;
-
-    // try checking for Janus protection, special path
-    if (verify_special_carrot_janus_protection(enote_ephemeral_pubkey,
-            input_context,
-            onetime_address,
-            k_view,
-            account_spend_pubkey,
-            nominal_anchor))
-        return true;
-
-    // neither attempt at checking Janus protection worked
-    return false;
-}
-//-------------------------------------------------------------------------------------------------------------------
 } //namespace carrot

src/carrot_core/enote_utils.h

@@ -1,4 +1,4 @@
-// Copyright (c) 2022, The Monero Project
+// Copyright (c) 2024, The Monero Project
 // 
 // All rights reserved.
 // 
@@ -364,7 +364,7 @@ bool try_get_carrot_amount(const crypto::hash &s_sender_receiver,
     rct::xmr_amount &amount_out,
     crypto::secret_key &amount_blinding_factor_out);
 /**
- * brief: verify_external_carrot_janus_protection - check normal external enote is Janus safe (i.e. can recompute D_e)
+ * brief: verify_carrot_external_janus_protection - check normal external enote is Janus safe (i.e. can recompute D_e)
  * param: nominal_anchor - anchor'
  * param: input_context -
  * param: nominal_address_spend_pubkey - K^j_s'
@@ -374,67 +374,11 @@ bool try_get_carrot_amount(const crypto::hash &s_sender_receiver,
  * param: enote_ephemeral_pubkey - D_e
  * return: true if this normal external enote is safe from Janus attacks
  */
-bool verify_external_carrot_janus_protection(const janus_anchor_t &nominal_anchor,
+bool verify_carrot_external_janus_protection(const janus_anchor_t &nominal_anchor,
     const input_context_t &input_context,
     const crypto::public_key &nominal_address_spend_pubkey,
     const crypto::public_key &nominal_address_view_pubkey,
     const bool is_subaddress,
     const payment_id_t nominal_payment_id,
     const crypto::x25519_pubkey &enote_ephemeral_pubkey);
-/**
- * brief: verify_external_carrot_janus_protection_receiver - check normal external enote is Janus safe (i.e. can
- *                                                  recompute D_e), and perhaps set nominal pid to null
- * param: nominal_anchor - anchor'
- * param: input_context -
- * param: nominal_address_spend_pubkey - K^j_s'
- * param: account_spend_pubkey - K_s
- * param: k_view - k_v
- * param: enote_ephemeral_pubkey - D_e
- * outparam: nominal_payment_id_inout - pid', first tries recomputing D_e with pid', then sets to null and tries again
- * return: true if this normal external enote is safe from Janus attacks
- */
-bool verify_external_carrot_janus_protection_receiver(const janus_anchor_t &nominal_anchor,
-    const input_context_t &input_context,
-    const crypto::public_key &nominal_address_spend_pubkey,
-    const crypto::public_key &account_spend_pubkey,
-    const crypto::secret_key &k_view,
-    const crypto::x25519_pubkey &enote_ephemeral_pubkey,
-    payment_id_t &nominal_payment_id_inout);
-/**
- * brief: verify_special_carrot_janus_protection - check special enote is Janus safe (i.e. can recompute anchor_sp)
- * param: enote_ephemeral_pubkey - D_e
- * param: input_context -
- * param: onetime_address - Ko
- * param: k_view - k_v
- * param: account_spend_pubkey - K_s
- * param: nominal_anchor - anchor'
- * return: true if this special enote is safe from Janus attacks
- */
-bool verify_special_carrot_janus_protection(const crypto::x25519_pubkey &enote_ephemeral_pubkey,
-    const input_context_t &input_context,
-    const crypto::public_key &onetime_address,
-    const crypto::secret_key &k_view,
-    const crypto::public_key &account_spend_pubkey,
-    const janus_anchor_t &nominal_anchor);
-/**
- * brief: verify_carrot_janus_protection - check whether a received Carrot enote is Janus protected (all paths)
- * param: input_context -
- * param: onetime_address - Ko
- * param: k_view - k_v
- * param: account_spend_pubkey - K_s
- * param: nominal_address_spend_pubkey - K^j_s'
- * param: enote_ephemeral_pubkey - D_e
- * param: nominal_anchor - anchor'
- * outparam: nominal_payment_id_inout - pass possible pid, set to null if the sender didn't explicitly bind to that pid
- * return: true if this received enote is safe from Janus attacks
- */
-bool verify_carrot_janus_protection(const input_context_t &input_context,
-    const crypto::public_key &onetime_address,
-    const crypto::secret_key &k_view,
-    const crypto::public_key &account_spend_pubkey,
-    const crypto::public_key &nominal_address_spend_pubkey,
-    const crypto::x25519_pubkey &enote_ephemeral_pubkey,
-    const janus_anchor_t &nominal_anchor,
-    payment_id_t &nominal_payment_id_inout);
-
 } //namespace carrot

src/carrot_core/hash_functions.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2022, The Monero Project
+// Copyright (c) 2024, The Monero Project
 // 
 // All rights reserved.
 // 

src/carrot_core/hash_functions.h

@@ -1,4 +1,4 @@
-// Copyright (c) 2022, The Monero Project
+// Copyright (c) 2024, The Monero Project
 // 
 // All rights reserved.
 // 

src/carrot_core/payment_proposal.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2022, The Monero Project
+// Copyright (c) 2024, The Monero Project
 // 
 // All rights reserved.
 // 

src/carrot_core/payment_proposal.h

@@ -1,4 +1,4 @@
-// Copyright (c) 2022, The Monero Project
+// Copyright (c) 2024, The Monero Project
 // 
 // All rights reserved.
 // 

src/carrot_core/transcript_fixed.h

@@ -1,4 +1,4 @@
-// Copyright (c) 2022-2024, The Monero Project
+// Copyright (c) 2024, The Monero Project
 // 
 // All rights reserved.
 // 
@@ -77,9 +77,6 @@ template <std::size_t N, const unsigned char domain_sep[N], typename... Ts>
 class SpFixedTranscript final
 {
 public:
-//public static member variables
-    static constexpr std::size_t size = 1 + SpFixedTranscript::domain_sep_size() + detail::sizeof_sum<Ts...>();
-
 //constructors
     /// normal constructor
     SpFixedTranscript(const Ts&... args)
@@ -102,6 +99,11 @@ public:
 //member functions
     constexpr const void* data() const noexcept { return m_transcript; }
 
+    static constexpr std::size_t size()
+    {
+        return 1 + domain_sep_size() + detail::sizeof_sum<Ts...>();
+    }
+
 //destructors
     ~SpFixedTranscript()
     {
@@ -171,7 +173,7 @@ private:
 
 //member variables
     /// the transcript buffer
-    unsigned char m_transcript[size];
+    unsigned char m_transcript[size()];
 };
 
 template <const auto & domain_sep, typename... Ts>

tests/unit_tests/carrot_core.cpp

@@ -31,6 +31,7 @@
 #include "carrot_core/account_secrets.h"
 #include "carrot_core/address_utils.h"
 #include "carrot_core/carrot_enote_scan.h"
+#include "carrot_core/device_ram_borrowed.h"
 #include "carrot_core/enote_utils.h"
 #include "carrot_core/payment_proposal.h"
 #include "crypto/crypto.h"
@@ -53,6 +54,12 @@ struct mock_carrot_keys
     crypto::public_key account_view_pubkey;
     crypto::public_key main_address_view_pubkey;
 
+    view_incoming_key_ram_borrowed_device k_view_dev;
+    view_balance_secret_ram_borrowed_device s_view_balance_dev;
+
+    mock_carrot_keys(): k_view_dev(k_view), s_view_balance_dev(s_view_balance)
+    {}
+
     static mock_carrot_keys generate()
     {
         mock_carrot_keys k;
@@ -183,7 +190,7 @@ TEST(carrot_core, main_address_normal_scan_completeness)
     const bool scan_success = try_scan_carrot_enote_external(enote,
         encrypted_payment_id,
         s_sender_receiver_unctx,
-        keys.k_view,
+        keys.k_view_dev,
         keys.account_spend_pubkey,
         recovered_sender_extension_g,
         recovered_sender_extension_t,
@@ -263,7 +270,7 @@ TEST(carrot_core, subaddress_normal_scan_completeness)
     const bool scan_success = try_scan_carrot_enote_external(enote,
         encrypted_payment_id,
         s_sender_receiver_unctx,
-        keys.k_view,
+        keys.k_view_dev,
         keys.account_spend_pubkey,
         recovered_sender_extension_g,
         recovered_sender_extension_t,
@@ -351,7 +358,7 @@ TEST(carrot_core, integrated_address_normal_scan_completeness)
     const bool scan_success = try_scan_carrot_enote_external(enote,
         encrypted_payment_id,
         s_sender_receiver_unctx,
-        keys.k_view,
+        keys.k_view_dev,
         keys.account_spend_pubkey,
         recovered_sender_extension_g,
         recovered_sender_extension_t,
@@ -429,7 +436,7 @@ TEST(carrot_core, main_address_special_scan_completeness)
         const bool scan_success = try_scan_carrot_enote_external(enote,
             std::nullopt,
             s_sender_receiver_unctx,
-            keys.k_view,
+            keys.k_view_dev,
             keys.account_spend_pubkey,
             recovered_sender_extension_g,
             recovered_sender_extension_t,
@@ -516,7 +523,7 @@ TEST(carrot_core, subaddress_special_scan_completeness)
         const bool scan_success = try_scan_carrot_enote_external(enote,
             std::nullopt,
             s_sender_receiver_unctx,
-            keys.k_view,
+            keys.k_view_dev,
             keys.account_spend_pubkey,
             recovered_sender_extension_g,
             recovered_sender_extension_t,
@@ -599,7 +606,7 @@ TEST(carrot_core, main_address_internal_scan_completeness)
         crypto::secret_key recovered_amount_blinding_factor;
         CarrotEnoteType recovered_enote_type;
         const bool scan_success = try_scan_carrot_enote_internal(enote,
-            keys.s_view_balance,
+            keys.s_view_balance_dev,
             recovered_sender_extension_g,
             recovered_sender_extension_t,
             recovered_address_spend_pubkey,
@@ -674,7 +681,7 @@ TEST(carrot_core, subaddress_internal_scan_completeness)
         crypto::secret_key recovered_amount_blinding_factor;
         CarrotEnoteType recovered_enote_type;
         const bool scan_success = try_scan_carrot_enote_internal(enote,
-            keys.s_view_balance,
+            keys.s_view_balance_dev,
             recovered_sender_extension_g,
             recovered_sender_extension_t,
             recovered_address_spend_pubkey,
@@ -745,7 +752,7 @@ TEST(carrot_core, main_address_coinbase_scan_completeness)
     crypto::public_key recovered_address_spend_pubkey;
     const bool scan_success = try_scan_carrot_coinbase_enote(enote,
         s_sender_receiver_unctx,
-        keys.k_view,
+        keys.k_view_dev,
         keys.account_spend_pubkey,
         recovered_sender_extension_g,
         recovered_sender_extension_t,

tests/unit_tests/carrot_transcript_fixed.cpp

@@ -46,15 +46,15 @@ TEST(carrot_transcript_fixed, ts_size)
 {
     static constexpr const unsigned char DS1[] = "perspicacious";
     const auto transcript1 = sp::make_fixed_transcript<DS1>((uint32_t)32);
-    EXPECT_EQ(1 + 13 + 4, transcript1.size);
+    EXPECT_EQ(1 + 13 + 4, transcript1.size());
 
     static constexpr const unsigned char DS2[] = "recrudescence";
     const auto transcript2 = sp::make_fixed_transcript<DS2>((uint32_t)32, (uint64_t)64);
-    EXPECT_EQ(1 + 13 + 4 + 8, transcript2.size);
+    EXPECT_EQ(1 + 13 + 4 + 8, transcript2.size());
 
     // vt = H_3(s_sr || input_context || Ko)
     const auto transcript_vt = sp::make_fixed_transcript<carrot::CARROT_DOMAIN_SEP_VIEW_TAG>(
         carrot::input_context_t{},
         crypto::public_key{});
-    EXPECT_EQ(1 + 15 + 33 + 32, transcript_vt.size);
+    EXPECT_EQ(1 + 15 + 33 + 32, transcript_vt.size());
 }