Crypto++ byte change at Crypto++ 6.0

[noloader]

This is based on feedback from Compiling bfx-cpp-api - Byte datatype undeclared on Stack Overflow. When using the current Crypto++ Master and soon to be Crypto++ 6.0, we moved our byte definition into the CryptoPP namespace.

The move was necessary because of C++17's std::byte and Microsoft's byte which is also in the global namespace. C++17 ensured something was going to break, so we stepped out of the way of the train and did what we were supposed to do years ago (namely, placed byte in our namespace). Now Microsoft SDKs are the one that's going to break things when it collides with C++17. Also see Crypto++ Issue 442 on the Crypto++ bug tracker and std::byte in the Crypto++ wiki.

The short of it for BFX-API is, you can do the following if you want to preserve old behavior. But keep in mind this is going to move the problem from Crypto++ to BFX-API:

// CRYPTOPP_NO_GLOBAL_BYTE signals byte is at CryptoPP::byte
#if defined(CRYPTOPP_NO_GLOBAL_BYTE)
  typedef unsigned char byte;
#endif

You could also perform the following which produces a similar effect:

// CRYPTOPP_NO_GLOBAL_BYTE signals byte is at CryptoPP::byte
#if defined(CRYPTOPP_NO_GLOBAL_BYTE)
  using CryptoPP::byte;
#endif

When we moved the Crypto++ byte to CryptoPP::byte we added the define CRYPTOPP_NO_GLOBAL_BYTE so downstream had a signal for remediations like above.

---

Here is a test using example.cpp from BFX-API. In the test, Crypto++ and BFX are side-by-side, so there is a bfx/ folder and a cryptopp/ folder.

$ g++ BitfinexAPI.cpp example.cpp -I ../ ../cryptopp/libcryptopp.a -o example.exe
BitfinexAPI.cpp: In static member function ‘static int BitfinexAPI::getBase64(const string&, std::__cxx11::string&)’:
BitfinexAPI.cpp:936:5: error: ‘byte’ was not declared in this scope
     byte buffer[1024] = {};
     ^~~~
BitfinexAPI.cpp:936:5: note: suggested alternative:
In file included from ../cryptopp/seckey.h:9:0,
                 from ../cryptopp/hmac.h:9,
                 from BitfinexAPI.cpp:37:
../cryptopp/config.h:222:23: note:   ‘CryptoPP::byte’
 typedef unsigned char byte;
                       ^~~~
BitfinexAPI.cpp:940:9: error: ‘buffer’ was not declared in this scope
         buffer[i] = content[i];
         ^~~~~~
BitfinexAPI.cpp:940:9: note: suggested alternative: ‘setbuffer’
         buffer[i] = content[i];
         ^~~~~~
         setbuffer
BitfinexAPI.cpp:943:21: error: ‘buffer’ was not declared in this scope
     StringSource ss(buffer, content.length(), true, new Base64Encoder( new StringSink(encoded), false));
                     ^~~~~~
BitfinexAPI.cpp:943:21: note: suggested alternative: ‘setbuffer’
     StringSource ss(buffer, content.length(), true, new Base64Encoder( new StringSink(encoded), false));
                     ^~~~~~
                     setbuffer
BitfinexAPI.cpp: In static member function ‘static int BitfinexAPI::getHmacSha384(const string&, const string&, std::__cxx11::string&)’:
BitfinexAPI.cpp:963:33: error: ISO C++ forbids declaration of ‘type name’ with no type [-fpermissive]
     SecByteBlock byteKey((const byte*)key.data(), key.size());
                                 ^~~~
BitfinexAPI.cpp:963:27: error: expected primary-expression before ‘const’
     SecByteBlock byteKey((const byte*)key.data(), key.size());
                           ^~~~~
BitfinexAPI.cpp:963:27: error: expected ‘)’ before ‘const’

[noloader]

This patch fixes the compile problem in a way that works with both Crypto++ 5.6.5 (and below) and Crypto++ 6.0 (and above):

i$ git diff
diff --git a/BitfinexAPI.cpp b/BitfinexAPI.cpp
index 151fe59..a940495 100644
--- a/BitfinexAPI.cpp
+++ b/BitfinexAPI.cpp
@@ -47,6 +47,11 @@ using std::to_string;



+// CRYPTOPP_NO_GLOBAL_BYTE signals byte is at CryptoPP::byte
+#if defined(CRYPTOPP_NO_GLOBAL_BYTE)
+using CryptoPP::byte;
+#endif
+
 //////////////////////////////////////////////////////////////////////////////
 // Constructor - destructor
 //////////////////////////////////////////////////////////////////////////////

[MMquant]

Should be patched now.

[noloader]

Thanks Petr. Sorry about the trouble it caused.