Added a bignum library to abstract possible implementations.

2 files changed, 16 insertions, 29 deletions

diff --git a/node/CMakeLists.txt b/node/CMakeLists.txt
index 6fe0ef7..9151cbc 100644
--- a/node/CMakeLists.txt
+++ b/node/CMakeLists.txt
@@ -1,7 +1,5 @@
 find_package(Boost COMPONENTS system program_options REQUIRED)
 
-find_package(gmp REQUIRED)
-
 add_executable(node
 	main.cpp
 	node.hpp node.cpp
@@ -25,8 +23,7 @@ target_link_libraries(node
 	PRIVATE Boost::system
 	PRIVATE log
 	PRIVATE cmix
+	PRIVATE cmix-bignum
 	PRIVATE cmix-network
 	PRIVATE cmix-protobuf
-	PRIVATE gmpxx
-	PRIVATE gmp
 )
diff --git a/node/node.cpp b/node/node.cpp
index 53dd30c..c9f6b14 100644
--- a/node/node.cpp
+++ b/node/node.cpp
@@ -2,7 +2,7 @@
 
 #include "logging.hpp"
 
-#include "gmpxx.h"
+#include "bignum.h"
 
 #include <iostream>
 
@@ -87,36 +87,26 @@ void Node::handle_initialization(const cmix_proto::Initialization& init)
 					
 		start_precomputation();
 	} else {
-		mpz_t shared;
-		mpz_init(shared);
-		mpz_import(shared, init.public_share().size(), -1, 1, 0, 0, init.public_share().data());
+		Bignum shared = allocate_bignum(init.public_share().size());
+		std::copy_n(init.public_share().data(), init.public_share().size(), shared.data);
+		Bignum my_share{keypair.pub, keypair.pub_len};
+		Bignum mod = allocate_bignum(keypair.pub_len);
+		Bignum new_shared = allocate_bignum(keypair.pub_len);
 		
-		mpz_t my_share;
-		mpz_init(my_share);
-		mpz_import(my_share, keypair.pub_len, -1, 1, 0, 0, keypair.pub);
-		
-		mpz_mul(shared, shared, my_share);
-		
-		mpz_t mod;
-		mpz_init(mod);
-		mpz_set_ui(mod, 2);
-		mpz_pow_ui(mod, mod, 255);
-		mpz_sub_ui(mod, mod, 19);
-		
-		mpz_mod(shared, shared, mod);
-		
-		std::vector<uint8_t> new_shared(keypair.pub_len, '\0');
-		size_t size;
-		mpz_export(new_shared.data(), &size, -1, 1, 0, 0, shared);
+		if(multiply_mod(&new_shared, shared, my_share, mod) != NoError) {
+			BOOST_LOG_TRIVIAL(fatal) << "Group multiplication failed";
+			throw std::runtime_error("Group multiplication failed");
+		}
 		
 		cmix_proto::Initialization init;
-		init.set_public_share(new_shared.data(), new_shared.size());
+		init.set_public_share(new_shared.data, new_shared.len);
 		
 		next_node.send(init);
+	
+		free_bignum(&shared);
+		free_bignum(&mod);
+		free_bignum(&new_shared);
 		
-		mpz_clear(shared);
-		mpz_clear(my_share);
-		mpz_clear(mod);
 	}
 }