Merge pull request #6351

81c5943 Remove temporary std::string creation in some hex->bin calls (vtnerd)
5fcc23a Move hex->bin conversion to monero copyright files and with less includes (vtnerd)
3387f0e Reduce template bloat in hex->bin for ZMQ json (vtnerd)

9 files changed, 135 insertions, 62 deletions

diff --git a/contrib/epee/include/hex.h b/contrib/epee/include/hex.h
index 4e8f90786..8443cb92f 100644
--- a/contrib/epee/include/hex.h
+++ b/contrib/epee/include/hex.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2019, The Monero Project
+// Copyright (c) 2017-2020, The Monero Project
 //
 // All rights reserved.
 //
@@ -80,9 +80,20 @@ namespace epee
     static void buffer_unchecked(char* out, const span<const std::uint8_t> src) noexcept;
   };
 
+  //! Convert hex in UTF8 encoding to binary
   struct from_hex
   {
-      //! \return An std::vector of unsigned integers from the `src`
-      static std::vector<uint8_t> vector(boost::string_ref src);
+    static bool to_string(std::string& out, boost::string_ref src);
+
+    static bool to_buffer(span<std::uint8_t> out, boost::string_ref src) noexcept;
+
+  private:
+    static bool to_buffer_unchecked(std::uint8_t* out, boost::string_ref src) noexcept;
+  };
+
+  //! Convert hex in current C locale encoding to binary
+  struct from_hex_locale
+  {
+      static std::vector<uint8_t> to_vector(boost::string_ref src);
   };
 }
diff --git a/contrib/epee/include/storages/parserse_base_utils.h b/contrib/epee/include/storages/parserse_base_utils.h
index 8a498130c..2256f6b83 100644
--- a/contrib/epee/include/storages/parserse_base_utils.h
+++ b/contrib/epee/include/storages/parserse_base_utils.h
@@ -31,6 +31,8 @@
 #include <algorithm>
 #include <boost/utility/string_ref.hpp>
 
+#include "misc_log_ex.h"
+
 #undef MONERO_DEFAULT_LOG_CATEGORY
 #define MONERO_DEFAULT_LOG_CATEGORY "serialization"
 
diff --git a/contrib/epee/include/string_tools.h b/contrib/epee/include/string_tools.h
index 319c0121b..2d9317d60 100644
--- a/contrib/epee/include/string_tools.h
+++ b/contrib/epee/include/string_tools.h
@@ -42,6 +42,7 @@
 #include <type_traits>
 #include <boost/lexical_cast.hpp>
 #include <boost/algorithm/string/predicate.hpp>
+#include <boost/utility/string_ref.hpp>
 #include "misc_log_ex.h"
 #include "storages/parserse_base_utils.h"
 #include "hex.h"
@@ -69,34 +70,9 @@ namespace string_tools
     return to_hex::string(to_byte_span(to_span(src)));
   }
   //----------------------------------------------------------------------------
-  inline bool parse_hexstr_to_binbuff(const epee::span<const char> s, epee::span<char>& res)
+  inline bool parse_hexstr_to_binbuff(const boost::string_ref s, std::string& res)
   {
-      if (s.size() != res.size() * 2)
-        return false;
-
-      unsigned char *dst = (unsigned char *)&res[0];
-      const unsigned char *src = (const unsigned char *)s.data();
-      for(size_t i = 0; i < s.size(); i += 2)
-      {
-        int tmp = *src++;
-        tmp = epee::misc_utils::parse::isx[tmp];
-        if (tmp == 0xff) return false;
-        int t2 = *src++;
-        t2 = epee::misc_utils::parse::isx[t2];
-        if (t2 == 0xff) return false;
-        *dst++ = (tmp << 4) | t2;
-      }
-
-      return true;
-  }
-  //----------------------------------------------------------------------------
-  inline bool parse_hexstr_to_binbuff(const std::string& s, std::string& res)
-  {
-    if (s.size() & 1)
-      return false;
-    res.resize(s.size() / 2);
-    epee::span<char> rspan((char*)&res[0], res.size());
-    return parse_hexstr_to_binbuff(epee::to_span(s), rspan);
+    return from_hex::to_string(res, s);
   }
   //----------------------------------------------------------------------------
 PUSH_WARNINGS
@@ -303,23 +279,20 @@ POP_WARNINGS
   }
   //----------------------------------------------------------------------------
   template<class t_pod_type>
-  bool hex_to_pod(const std::string& hex_str, t_pod_type& s)
+  bool hex_to_pod(const boost::string_ref hex_str, t_pod_type& s)
   {
-    static_assert(std::is_pod<t_pod_type>::value, "expected pod type");
-    if(sizeof(s)*2 != hex_str.size())
-      return false;
-    epee::span<char> rspan((char*)&s, sizeof(s));
-    return parse_hexstr_to_binbuff(epee::to_span(hex_str), rspan);
+    static_assert(std::is_standard_layout<t_pod_type>(), "expected standard layout type");
+    return from_hex::to_buffer(as_mut_byte_span(s), hex_str);
   }
   //----------------------------------------------------------------------------
   template<class t_pod_type>
-  bool hex_to_pod(const std::string& hex_str, tools::scrubbed<t_pod_type>& s)
+  bool hex_to_pod(const boost::string_ref hex_str, tools::scrubbed<t_pod_type>& s)
   {
     return hex_to_pod(hex_str, unwrap(s));
   }
   //----------------------------------------------------------------------------
   template<class t_pod_type>
-  bool hex_to_pod(const std::string& hex_str, epee::mlocked<t_pod_type>& s)
+  bool hex_to_pod(const boost::string_ref hex_str, epee::mlocked<t_pod_type>& s)
   {
     return hex_to_pod(hex_str, unwrap(s));
   }
diff --git a/contrib/epee/src/hex.cpp b/contrib/epee/src/hex.cpp
index 558983f7e..b25ce5421 100644
--- a/contrib/epee/src/hex.cpp
+++ b/contrib/epee/src/hex.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2019, The Monero Project
+// Copyright (c) 2017-2020, The Monero Project
 //
 // All rights reserved.
 //
@@ -33,6 +33,8 @@
 #include <ostream>
 #include <stdexcept>
 
+#include "storages/parserse_base_utils.h"
+
 namespace epee
 {
   namespace
@@ -84,7 +86,42 @@ namespace epee
     return write_hex(out, src);
   }
 
-  std::vector<uint8_t> from_hex::vector(boost::string_ref src)
+
+  bool from_hex::to_string(std::string& out, const boost::string_ref src)
+  {
+    out.resize(src.size() / 2);
+    return to_buffer_unchecked(reinterpret_cast<std::uint8_t*>(&out[0]), src);
+  }
+
+  bool from_hex::to_buffer(span<std::uint8_t> out, const boost::string_ref src) noexcept
+  {
+    if (src.size() / 2 != out.size())
+      return false;
+    return to_buffer_unchecked(out.data(), src);
+  }
+
+  bool from_hex::to_buffer_unchecked(std::uint8_t* dst, const boost::string_ref s) noexcept
+  {
+      if (s.size() % 2 != 0)
+        return false;
+
+      const unsigned char *src = (const unsigned char *)s.data();
+      for(size_t i = 0; i < s.size(); i += 2)
+      {
+        int tmp = *src++;
+        tmp = epee::misc_utils::parse::isx[tmp];
+        if (tmp == 0xff) return false;
+        int t2 = *src++;
+        t2 = epee::misc_utils::parse::isx[t2];
+        if (t2 == 0xff) return false;
+        *dst++ = (tmp << 4) | t2;
+      }
+
+      return true;
+  }
+
+
+  std::vector<uint8_t> from_hex_locale::to_vector(const boost::string_ref src)
   {
     // should we include a specific character
     auto include = [](char input) {
diff --git a/src/rpc/rpc_args.cpp b/src/rpc/rpc_args.cpp
index dcb804d3e..9153e76ea 100644
--- a/src/rpc/rpc_args.cpp
+++ b/src/rpc/rpc_args.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2014-2019, The Monero Project
+// Copyright (c) 2014-2020, The Monero Project
 //
 // All rights reserved.
 //
@@ -51,7 +51,7 @@ namespace cryptonote
         const std::vector<std::string> ssl_allowed_fingerprints = command_line::get_arg(vm, arg.rpc_ssl_allowed_fingerprints);
 
         std::vector<std::vector<uint8_t>> allowed_fingerprints{ ssl_allowed_fingerprints.size() };
-        std::transform(ssl_allowed_fingerprints.begin(), ssl_allowed_fingerprints.end(), allowed_fingerprints.begin(), epee::from_hex::vector);
+        std::transform(ssl_allowed_fingerprints.begin(), ssl_allowed_fingerprints.end(), allowed_fingerprints.begin(), epee::from_hex_locale::to_vector);
         for (const auto &fpr: allowed_fingerprints)
         {
           if (fpr.size() != SSL_FINGERPRINT_SIZE)
diff --git a/src/serialization/json_object.cpp b/src/serialization/json_object.cpp
index e98ba0483..926eb18c0 100644
--- a/src/serialization/json_object.cpp
+++ b/src/serialization/json_object.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2019, The Monero Project
+// Copyright (c) 2016-2020, The Monero Project
 // 
 // All rights reserved.
 // 
@@ -32,7 +32,11 @@
 #include <boost/variant/apply_visitor.hpp>
 #include <limits>
 #include <type_traits>
-#include "string_tools.h"
+
+// drop macro from windows.h
+#ifdef GetObject
+  #undef GetObject
+#endif
 
 namespace cryptonote
 {
@@ -109,6 +113,19 @@ namespace
   }
 }
 
+void read_hex(const rapidjson::Value& val, epee::span<std::uint8_t> dest)
+{
+  if (!val.IsString())
+  {
+    throw WRONG_TYPE("string");
+  }
+
+  if (!epee::from_hex::to_buffer(dest, {val.GetString(), val.Size()}))
+  {
+    throw BAD_INPUT();
+  }
+}
+
 void toJsonValue(rapidjson::Writer<rapidjson::StringBuffer>& dest, const rapidjson::Value& src)
 {
   src.Accept(dest);
diff --git a/src/serialization/json_object.h b/src/serialization/json_object.h
index a1a5105d5..664b539b5 100644
--- a/src/serialization/json_object.h
+++ b/src/serialization/json_object.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2019, The Monero Project
+// Copyright (c) 2016-2020, The Monero Project
 // 
 // All rights reserved.
 // 
@@ -30,7 +30,6 @@
 
 #include <boost/utility/string_ref.hpp>
 #include <cstring>
-#include "string_tools.h" // out of order because windows.h GetObject macro conflicts with GenericValue<..>::GetObject()
 #include <rapidjson/document.h>
 #include <rapidjson/stringbuffer.h>
 #include <rapidjson/writer.h>
@@ -39,6 +38,8 @@
 #include "rpc/message_data_structs.h"
 #include "cryptonote_protocol/cryptonote_protocol_defs.h"
 #include "common/sfinae_helpers.h"
+#include "hex.h"
+#include "span.h"
 
 #define OBJECT_HAS_MEMBER_OR_THROW(val, key) \
   do \
@@ -118,6 +119,8 @@ inline constexpr bool is_to_hex()
   return std::is_pod<Type>() && !std::is_integral<Type>();
 }
 
+void read_hex(const rapidjson::Value& val, epee::span<std::uint8_t> dest);
+
 // POD to json key
 template <class Type>
 inline typename std::enable_if<is_to_hex<Type>()>::type toJsonKey(rapidjson::Writer<rapidjson::StringBuffer>& dest, const Type& pod)
@@ -137,18 +140,8 @@ inline typename std::enable_if<is_to_hex<Type>()>::type toJsonValue(rapidjson::W
 template <class Type>
 inline typename std::enable_if<is_to_hex<Type>()>::type fromJsonValue(const rapidjson::Value& val, Type& t)
 {
-  if (!val.IsString())
-  {
-    throw WRONG_TYPE("string");
-  }
-
-  //TODO: handle failure to convert hex string to POD type
-  bool success = epee::string_tools::hex_to_pod(val.GetString(), t);
-
-  if (!success)
-  {
-    throw BAD_INPUT();
-  }
+  static_assert(std::is_standard_layout<Type>(), "expected standard layout type");
+  json::read_hex(val, epee::as_mut_byte_span(t));
 }
 
 void toJsonValue(rapidjson::Writer<rapidjson::StringBuffer>& dest, const rapidjson::Value& src);
diff --git a/src/wallet/wallet2.cpp b/src/wallet/wallet2.cpp
index 70ceddad3..f05a67315 100644
--- a/src/wallet/wallet2.cpp
+++ b/src/wallet/wallet2.cpp
@@ -355,7 +355,7 @@ std::unique_ptr<tools::wallet2> make_basic(const boost::program_options::variabl
   else if (!daemon_ssl_ca_file.empty() || !daemon_ssl_allowed_fingerprints.empty())
   {
     std::vector<std::vector<uint8_t>> ssl_allowed_fingerprints{ daemon_ssl_allowed_fingerprints.size() };
-    std::transform(daemon_ssl_allowed_fingerprints.begin(), daemon_ssl_allowed_fingerprints.end(), ssl_allowed_fingerprints.begin(), epee::from_hex::vector);
+    std::transform(daemon_ssl_allowed_fingerprints.begin(), daemon_ssl_allowed_fingerprints.end(), ssl_allowed_fingerprints.begin(), epee::from_hex_locale::to_vector);
     for (const auto &fpr: ssl_allowed_fingerprints)
     {
       THROW_WALLET_EXCEPTION_IF(fpr.size() != SSL_FINGERPRINT_SIZE, tools::error::wallet_internal_error,
diff --git a/tests/unit_tests/epee_utils.cpp b/tests/unit_tests/epee_utils.cpp
index 513c2227c..42bbb26bb 100644
--- a/tests/unit_tests/epee_utils.cpp
+++ b/tests/unit_tests/epee_utils.cpp
@@ -824,14 +824,14 @@ TEST(ToHex, String)
 
 }
 
-TEST(FromHex, String)
+TEST(HexLocale, String)
 {
     // the source data to encode and decode
     std::vector<uint8_t> source{{ 0x00, 0xFF, 0x0F, 0xF0 }};
 
     // encode and decode the data
     auto hex = epee::to_hex::string({ source.data(), source.size() });
-    auto decoded = epee::from_hex::vector(hex);
+    auto decoded = epee::from_hex_locale::to_vector(hex);
 
     // encoded should be twice the size and should decode to the exact same data
     EXPECT_EQ(source.size() * 2, hex.size());
@@ -840,7 +840,7 @@ TEST(FromHex, String)
     // we will now create a padded hex string, we want to explicitly allow
     // decoding it this way also, ignoring spaces and colons between the numbers
     hex.assign("00:ff 0f:f0");
-    EXPECT_EQ(source, epee::from_hex::vector(hex));
+    EXPECT_EQ(source, epee::from_hex_locale::to_vector(hex));
 }
 
 TEST(ToHex, Array)
@@ -902,6 +902,46 @@ TEST(ToHex, Formatted)
   EXPECT_EQ(expected, out.str());
 }
 
+TEST(FromHex, ToString)
+{
+  static constexpr const char hex[] = u8"deadbeeffY";
+  static constexpr const char binary[] = {
+    char(0xde), char(0xad), char(0xbe), char(0xef), 0x00
+  };
+
+  std::string out{};
+  EXPECT_FALSE(epee::from_hex::to_string(out, hex));
+
+  boost::string_ref portion{hex};
+  portion.remove_suffix(1);
+  EXPECT_FALSE(epee::from_hex::to_string(out, portion));
+
+  portion.remove_suffix(1);
+  EXPECT_TRUE(epee::from_hex::to_string(out, portion));
+  EXPECT_EQ(std::string{binary}, out);
+}
+
+TEST(FromHex, ToBuffer)
+{
+  static constexpr const char hex[] = u8"deadbeeffY";
+  static constexpr const std::uint8_t binary[] = {0xde, 0xad, 0xbe, 0xef};
+
+  std::vector<std::uint8_t> out{};
+  out.resize(sizeof(binary));
+  EXPECT_FALSE(epee::from_hex::to_buffer(epee::to_mut_span(out), hex));
+
+  boost::string_ref portion{hex};
+  portion.remove_suffix(1);
+  EXPECT_FALSE(epee::from_hex::to_buffer(epee::to_mut_span(out), portion));
+
+  portion.remove_suffix(1);
+  EXPECT_FALSE(epee::from_hex::to_buffer({out.data(), out.size() - 1}, portion));
+
+  EXPECT_TRUE(epee::from_hex::to_buffer(epee::to_mut_span(out), portion));
+  const std::vector<std::uint8_t> expected{std::begin(binary), std::end(binary)};
+  EXPECT_EQ(expected, out);
+}
+
 TEST(StringTools, BuffToHex)
 {
   const std::vector<unsigned char> all_bytes = get_all_bytes();