Working implementation of elgamal in 2048 bit multiplicative group.

6 files changed, 46 insertions, 20 deletions

diff --git a/client/cmixclient.cpp b/client/cmixclient.cpp
index d7e1387..e3b33b6 100644
--- a/client/cmixclient.cpp
+++ b/client/cmixclient.cpp
@@ -66,7 +66,7 @@ void CMixClient::handle_key_exchange(size_t node_id, cmix_proto::KeyExchange con
 	if(std::all_of(shared_values.begin(), shared_values.end(), [](auto const& value){return value != nullptr;})) {
 		size_t len = get_group_element_array_size(&cmix_ctx);
 		std::vector<char> vec(len, '\0');
-		std::string s = "\1";
+		std::string s = "abcdefghijklmnopqrstuvwxyz";
 		std::copy_n(s.begin(), s.size(), vec.begin() + 1);
 		
 		cmix_proto::UserMessage message;
diff --git a/libcmix-crypto/elgamal/gcrypt/gcrypt_elgamal.c b/libcmix-crypto/elgamal/gcrypt/gcrypt_elgamal.c
index 8a6fb7e..2f48a9e 100644
--- a/libcmix-crypto/elgamal/gcrypt/gcrypt_elgamal.c
+++ b/libcmix-crypto/elgamal/gcrypt/gcrypt_elgamal.c
@@ -9,7 +9,7 @@
 static gcry_mpi_t p;
 static gcry_mpi_t q;
 static gcry_mpi_t g;
-static unsigned int nr_bytes = 2;
+static unsigned int nr_bytes = 256;
 
 void check(gcry_error_t error) {
 	if (error) {
@@ -45,13 +45,13 @@ void gcrypt_elgamal_initialize(void) {
 	gcry_control (GCRYCTL_INITIALIZATION_FINISHED, 0);
 	
 	//leading 0 as specified by libgcrypt
-	//char p_hex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
-	//char q_hex[] = "08CF83642A709A097B447997640129DA299B1A47D1EB3750BA308B0FE64F5FBD3";
-	//char g_hex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
+	char p_hex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
+	char q_hex[] = "08CF83642A709A097B447997640129DA299B1A47D1EB3750BA308B0FE64F5FBD3";
+	char g_hex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
 	
-	char p_hex[] = "0b";
-	char q_hex[] = "00";
-	char g_hex[] = "02";
+	//char p_hex[] = "0b";
+	//char q_hex[] = "00";
+	//char g_hex[] = "02";
 	
 	size_t nr_bytes_scanned;
 	gcry_error_t error;
diff --git a/libcmix-network/client.hpp b/libcmix-network/client.hpp
index df8c0c4..c583628 100644
--- a/libcmix-network/client.hpp
+++ b/libcmix-network/client.hpp
@@ -174,7 +174,6 @@ public:
 	 * \param message_handler The function to call when a message has been received.
 	 */
 	void async_receive(MessageHandler message_handler) {
-		BOOST_LOG_TRIVIAL(trace) << socket.get();
 		using namespace boost::asio::placeholders;
 	
 		boost::asio::async_read(
diff --git a/libcmix/cmix.c b/libcmix/cmix.c
index 4465011..9db4dbb 100644
--- a/libcmix/cmix.c
+++ b/libcmix/cmix.c
@@ -268,31 +268,38 @@ enum cmix_error post_process(struct CMixContext* ctx, char* r_out, char* m_out,
 	GroupElement msg = ctx->api.array_to_element(m_epirs, get_group_element_array_size(ctx), true);
 	GroupElement pirs = ctx->api.multiply(D, msg, true);
 	element_to_buffer(ctx, m_out, pirs);
-	GroupElement new_r = ctx->api.multiply(x, D, true);
-	element_to_buffer(ctx, r_out, new_r);
+	//GroupElement new_r = ctx->api.multiply(x, D, true);
+	//element_to_buffer(ctx, r_out, new_r);
+	
+	memcpy(r_out, r_epirs, get_group_element_array_size(ctx));
 	
 	ctx->pirs[index] = pirs; // this is not always usable as only the last node will be able to use this effectively, but we store it anyways.
 	
 	ctx->api.free_group_element(x);
 	ctx->api.free_group_element(D);
 	ctx->api.free_group_element(msg);
-	ctx->api.free_group_element(new_r);
+	//ctx->api.free_group_element(new_r);
 	
 	return no_error;
 }
 
 enum cmix_error blind_message(struct CMixContext const* ctx, char* m_out, char const* message, GroupElement const* keys, size_t const nr_nodes) {
-	size_t len = get_group_element_array_size(ctx);
+	size_t len = get_group_element_array_size(ctx); 
+	
+	GroupElement* intermediates = (GroupElement*) calloc(nr_nodes + 1, sizeof(GroupElement));
 	
-	GroupElement mes = ctx->api.array_to_element(message, len, true);
+	intermediates[0] = ctx->api.array_to_element(message, len, true);
 	
 	for(size_t i = 0; i < nr_nodes; ++i) {
-		ctx->api.multiply(mes, mes, keys[i]);
+		intermediates[i+1] = ctx->api.multiply(intermediates[i], keys[i], false);
 	}
 	
-	element_to_buffer(ctx, m_out, mes);
+	element_to_buffer(ctx, m_out, intermediates[nr_nodes]);
 	
-	ctx->api.free_group_element(mes);
+	for(size_t i = 0; i < nr_nodes + 1; ++i) {
+		ctx->api.free_group_element(intermediates[i]);
+	}
+	free(intermediates);
 	
 	return no_error;
 }
diff --git a/node/node.cpp b/node/node.cpp
index 5bce063..0f2bae5 100644
--- a/node/node.cpp
+++ b/node/node.cpp
@@ -215,7 +215,19 @@ void Node::start_realtime_phase() {
 			generate_random_message(&cmix_ctx, v.data());
 			swap_k_for_r(&cmix_ctx, &(*realpre.mutable_m(index))[0], v.data(), data[handle].shared_value, index);
 		} else {
-			swap_k_for_r(&cmix_ctx, &(*realpre.mutable_m(index))[0], queue.front().data(), data[handle].shared_value, index);
+			std::string x = to_string(data.at(handle).shared_value, cmix_ctx);
+			{
+				std::stringstream ss;
+				ss << "shared_key: ";
+				for(auto&& c : x) {
+					ss << "\\" << std::setw(3) << std::setfill('0') << std::oct << (unsigned int) c;
+				}
+				BOOST_LOG_TRIVIAL(trace) << ss.str();
+			}
+		
+			BOOST_LOG_TRIVIAL(trace) << 
+		
+			swap_k_for_r(&cmix_ctx, &(*realpre.mutable_m(index))[0], queue.front().data(), data.at(handle).shared_value, index);
 		}
 		*realpre.mutable_h(index) = handle;
 	}
diff --git a/node/node_node.cpp b/node/node_node.cpp
index f24ff0a..e0ee237 100644
--- a/node/node_node.cpp
+++ b/node/node_node.cpp
@@ -115,8 +115,6 @@ cmix_proto::PrePost fill_precomputation_post_message(CMixContext& ctx, T const&
 			BOOST_LOG_TRIVIAL(trace) << ss.str();
 		} 
 		
-		*prepost.mutable_r_epirs(i) = rs.Get(i);
-		*prepost.mutable_m_epirs(i) = ms.Get(i);
 	}
 	
 	return prepost;
@@ -132,6 +130,16 @@ cmix_proto::RealPre fill_realtime_pre_message(CMixContext& ctx, T const& hs, T c
 		realpre.add_m();
 		realpre.mutable_m(i)->resize(len);
 		
+		std::string x = to_string(data.at(hs.Get(i)).shared_value, ctx);
+		{
+			std::stringstream ss;
+			ss << "shared_key: ";
+			for(auto&& c : x) {
+				ss << "\\" << std::setw(3) << std::setfill('0') << std::oct << (unsigned int) c;
+			}
+			BOOST_LOG_TRIVIAL(trace) << ss.str();
+		}
+		
 		swap_k_for_r(
 			&ctx,
 			&(*realpre.mutable_m(i))[0],