Add view tags to outputs to reduce wallet scanning time

Implements view tags as proposed by @UkoeHB in MRL issue
https://github.com/monero-project/research-lab/issues/73

At tx construction, the sender adds a 1-byte view tag to each
output. The view tag is derived from the sender-receiver
shared secret. When scanning for outputs, the receiver can
check the view tag for a match, in order to reduce scanning
time. When the view tag does not match, the wallet avoids the
more expensive EC operations when deriving the output public
key using the shared secret.

1 files changed, 69 insertions, 1 deletions

diff --git a/tests/core_tests/rct.h b/tests/core_tests/rct.h
index dee074e4c..c20e8a580 100644
--- a/tests/core_tests/rct.h
+++ b/tests/core_tests/rct.h
@@ -70,7 +70,7 @@ struct gen_rct_tx_validation_base : public test_chain_unit_base
   }
 
   bool generate_with_full(std::vector<test_event_entry>& events, const int *out_idx, int mixin,
-      uint64_t amount_paid, size_t second_rewind, uint8_t last_version, const rct::RCTConfig &rct_config, bool valid,
+      uint64_t amount_paid, size_t second_rewind, uint8_t last_version, const rct::RCTConfig &rct_config, bool use_view_tags, bool valid,
       const std::function<void(std::vector<cryptonote::tx_source_entry> &sources, std::vector<cryptonote::tx_destination_entry> &destinations)> &pre_tx,
       const std::function<void(cryptonote::transaction &tx)> &post_tx) const;
   bool generate_with(std::vector<test_event_entry>& events, const int *out_idx, int mixin,
@@ -266,6 +266,74 @@ struct gen_rct_tx_rct_altered_extra : public gen_rct_tx_validation_base
 };
 template<> struct get_test_options<gen_rct_tx_rct_altered_extra>: public get_test_options<gen_rct_tx_validation_base> {};
 
+struct gen_rct_tx_pre_rct_has_no_view_tag_before_hf_view_tags : public gen_rct_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_rct_tx_pre_rct_has_no_view_tag_before_hf_view_tags>: public get_test_options<gen_rct_tx_validation_base> {};
+
+struct gen_rct_tx_pre_rct_has_no_view_tag_from_hf_view_tags : public gen_rct_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_rct_tx_pre_rct_has_no_view_tag_from_hf_view_tags> {
+  const std::pair<uint8_t, uint64_t> hard_forks[5] = {std::make_pair(1, 0), std::make_pair(2, 1), std::make_pair(4, 65), std::make_pair(HF_VERSION_VIEW_TAGS, 69), std::make_pair(0, 0)};
+  const cryptonote::test_options test_options = {
+    hard_forks, 0
+  };
+};
+
+struct gen_rct_tx_pre_rct_has_view_tag_before_hf_view_tags : public gen_rct_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_rct_tx_pre_rct_has_view_tag_before_hf_view_tags>: public get_test_options<gen_rct_tx_validation_base> {};
+
+struct gen_rct_tx_pre_rct_has_view_tag_from_hf_view_tags : public gen_rct_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_rct_tx_pre_rct_has_view_tag_from_hf_view_tags> {
+  const std::pair<uint8_t, uint64_t> hard_forks[5] = {std::make_pair(1, 0), std::make_pair(2, 1), std::make_pair(4, 65), std::make_pair(HF_VERSION_VIEW_TAGS, 69), std::make_pair(0, 0)};
+  const cryptonote::test_options test_options = {
+    hard_forks, 0
+  };
+};
+
+struct gen_rct_tx_rct_has_no_view_tag_before_hf_view_tags : public gen_rct_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_rct_tx_rct_has_no_view_tag_before_hf_view_tags>: public get_test_options<gen_rct_tx_validation_base> {};
+
+struct gen_rct_tx_rct_has_no_view_tag_from_hf_view_tags : public gen_rct_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_rct_tx_rct_has_no_view_tag_from_hf_view_tags> {
+  const std::pair<uint8_t, uint64_t> hard_forks[5] = {std::make_pair(1, 0), std::make_pair(2, 1), std::make_pair(4, 65), std::make_pair(HF_VERSION_VIEW_TAGS+1, 69), std::make_pair(0, 0)};
+  const cryptonote::test_options test_options = {
+    hard_forks, 0
+  };
+};
+
+struct gen_rct_tx_rct_has_view_tag_before_hf_view_tags : public gen_rct_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_rct_tx_rct_has_view_tag_before_hf_view_tags>: public get_test_options<gen_rct_tx_validation_base> {};
+
+struct gen_rct_tx_rct_has_view_tag_from_hf_view_tags : public gen_rct_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_rct_tx_rct_has_view_tag_from_hf_view_tags> {
+  const std::pair<uint8_t, uint64_t> hard_forks[5] = {std::make_pair(1, 0), std::make_pair(2, 1), std::make_pair(4, 65), std::make_pair(HF_VERSION_VIEW_TAGS, 69), std::make_pair(0, 0)};
+  const cryptonote::test_options test_options = {
+    hard_forks, 0
+  };
+};
+
 struct gen_rct_tx_uses_output_too_early : public gen_rct_tx_validation_base
 {
   bool generate(std::vector<test_event_entry>& events) const;