Fixes some memory leaks and consequent incorrect frees.

8 files changed, 39 insertions, 20 deletions

diff --git a/client/cmixclient.cpp b/client/cmixclient.cpp
index f05b200..3abe1eb 100644
--- a/client/cmixclient.cpp
+++ b/client/cmixclient.cpp
@@ -16,17 +16,17 @@ void CMixClient::key_exchange(size_t node_id) {
 	
 	cmix_proto::KeyExchange ke;
 	ke.set_public_key(buffer, len);
-	
-	free(buffer);
+	api.free_buffer(buffer);
 	
 	data.at(node_id).secret_value = api.get_group_element(true);
-	void* shared_value = api.get_key_exchange_value(data.at(node_id).secret_value);
 	
-	api.element_to_array(&buffer, &len, shared_value);
+	GroupElement shared_value = api.get_key_exchange_value(data.at(node_id).secret_value);
 	
+	api.element_to_array(&buffer, &len, shared_value);
 	ke.set_value(buffer, len);
+	api.free_buffer(buffer);
 	
-	free(buffer);
+	api.free_group_element(shared_value);
 	
 	network_connections.at(node_id).async_send(ke);
 	network_connections.at(node_id).async_receive([node_id, this](cmix_proto::CMixMessage message) {
diff --git a/client/cmixclient.hpp b/client/cmixclient.hpp
index 2df754b..f1c726d 100644
--- a/client/cmixclient.hpp
+++ b/client/cmixclient.hpp
@@ -37,7 +37,7 @@ struct NetworkDetails {
 class CMixClient {
 
 	struct NodeData {
-		void* secret_value;
+		GroupElement secret_value;
 		SharedKey shared_value;
 	};
 
diff --git a/libcmix-crypto/api.h b/libcmix-crypto/api.h
index f50cee0..8c40d23 100644
--- a/libcmix-crypto/api.h
+++ b/libcmix-crypto/api.h
@@ -53,6 +53,11 @@ typedef void(*ElementToArray)(unsigned char**, size_t* size, GroupElement);
 /*!
  *
  */
+typedef void(*BufferDeleter)(void*);
+
+/*!
+ *
+ */
 typedef GroupElement(*ArrayToElement)(char const*, size_t size, bool);
 
 /*!
@@ -93,6 +98,7 @@ struct Api {
 	KeyPairCreator create_key_pair; ///< Pointer to keypair creation function
 	KeyPairDeleter free_key_pair; ///< Pointer to keypair deletor function
 	ElementToArray element_to_array; ///< Get the array representation of a public key
+	BufferDeleter free_buffer; ///< frees library allocated buffers.
 	ArrayToElement array_to_element; ///< The the GroupElement representation of this array;
 	GroupElementGetter get_group_element; ///< get group element
 	GroupElementDeleter free_group_element; ///< frees a base type of the cryptolibrary.
diff --git a/libcmix-crypto/curve25519/curve25519.c b/libcmix-crypto/curve25519/curve25519.c
index 1a83308..6eaaafc 100644
--- a/libcmix-crypto/curve25519/curve25519.c
+++ b/libcmix-crypto/curve25519/curve25519.c
@@ -14,6 +14,7 @@ struct Api get_curve25519_implementation()
 		NULL,
 		NULL,
 		NULL,
+		NULL,
 		&curve25519_add_public_share,
 		&curve25519_derive_shared_key,
 		&curve25519_shared_key_deleter,
diff --git a/libcmix-crypto/elgamal/elgamal.c b/libcmix-crypto/elgamal/elgamal.c
index 3ee86d7..336d974 100644
--- a/libcmix-crypto/elgamal/elgamal.c
+++ b/libcmix-crypto/elgamal/elgamal.c
@@ -8,6 +8,7 @@ struct Api get_elgamal_implementation()
 		elgamal_create_keypair,
 		elgamal_delete_keypair,
 		elgamal_element_to_array,
+		elgamal_free_buffer,
 		elgamal_array_to_element,
 		elgamal_get_group_element,
 		elgamal_delete_group_element,
diff --git a/libcmix-crypto/elgamal/elgamal.h b/libcmix-crypto/elgamal/elgamal.h
index 746b726..71046c5 100644
--- a/libcmix-crypto/elgamal/elgamal.h
+++ b/libcmix-crypto/elgamal/elgamal.h
@@ -18,6 +18,8 @@ extern KeyPairDeleter elgamal_delete_keypair;
 
 extern ElementToArray elgamal_element_to_array;
 
+extern BufferDeleter elgamal_free_buffer;
+
 extern ArrayToElement elgamal_array_to_element;
 
 extern GroupElementGetter elgamal_get_group_element;
diff --git a/libcmix-crypto/elgamal/gcrypt/gcrypt_elgamal.c b/libcmix-crypto/elgamal/gcrypt/gcrypt_elgamal.c
index 1dd0690..a0512dd 100644
--- a/libcmix-crypto/elgamal/gcrypt/gcrypt_elgamal.c
+++ b/libcmix-crypto/elgamal/gcrypt/gcrypt_elgamal.c
@@ -67,7 +67,7 @@ struct KeyPair gcrypt_elgamal_create_keypair() {
 	gcry_error_t error;
 	
 	void* bytes = gcry_random_bytes_secure(2048/8, GCRY_VERY_STRONG_RANDOM);
-	gcry_mpi_t x = gcry_mpi_snew(2048);
+	gcry_mpi_t x;
 	error = gcry_mpi_scan(&x, GCRYMPI_FMT_USG, bytes, 2048/8, &parse_error_offset);
 	check(error);
 	
@@ -105,12 +105,17 @@ void gcrypt_elgamal_element_to_array(unsigned char** buffer, size_t* len, void*
 	check(error);
 }
 
+void gcrypt_elgamal_free_buffer(void* buffer) {
+	gcry_free(buffer);
+}
+
 void* gcrypt_elgamal_array_to_element(char const* buffer, size_t len, bool secure) {
 	size_t error_pos;
 	gcry_error_t error;
 	
-	gcry_mpi_t mpi = secure ? gcry_mpi_snew(0) : gcry_mpi_new(0);
+	gcry_mpi_t mpi;
 	error = gcry_mpi_scan(&mpi, GCRYMPI_FMT_USG, buffer, len, &error_pos);
+	gcry_mpi_set_flag(mpi, GCRYMPI_FLAG_SECURE);
 	check(error);
 	
 	return mpi;
@@ -121,8 +126,10 @@ void* gcrypt_elgamal_get_group_element(bool secure) {
 	gcry_error_t error;
 	
 	void* bytes = gcry_random_bytes_secure(2048/8, GCRY_VERY_STRONG_RANDOM);
-	gcry_mpi_t a = secure ? gcry_mpi_snew(2048) : gcry_mpi_new(2048);
+	gcry_mpi_t a;
 	error = gcry_mpi_scan(&a, GCRYMPI_FMT_USG, bytes, 2048/8, &parse_error_offset);
+	//random bytes generated with GCRY{,_VERY}_STRONG_RANDOM are generated in "secure memory"
+	//so secure is unused.
 	check(error);
 	
 	gcry_free(bytes);
@@ -149,8 +156,6 @@ void gcrypt_elgamal_delete_group_element(void* el) {
 	gcry_mpi_release((gcry_mpi_t) el);
 }
 
-
-
 void gcrypt_elgamal_add_public_share(char** buffer, size_t* out_len, char const* share, size_t in_len, void* pubkey) {
 	
 	gcry_error_t error;
@@ -167,6 +172,9 @@ void gcrypt_elgamal_add_public_share(char** buffer, size_t* out_len, char const*
 	
 	error = gcry_mpi_aprint(GCRYMPI_FMT_USG, (unsigned char**) buffer, out_len, result);
 	check(error);
+	
+	gcry_mpi_release(mpi_share);
+	gcry_mpi_release(result);
 }
 
 struct SharedKey gcrypt_elgamal_derive_shared_key(struct KeyPair keypair, unsigned char const* other_pub, size_t pub_len, unsigned char const* value, size_t value_len, void* priv_value, bool swap) {
@@ -227,6 +235,7 @@ Initializer elgamal_initialize = &gcrypt_elgamal_initialize;
 KeyPairCreator elgamal_create_keypair = &gcrypt_elgamal_create_keypair;
 KeyPairDeleter elgamal_delete_keypair = &gcrypt_elgamal_delete_keypair;
 ElementToArray elgamal_element_to_array = &gcrypt_elgamal_element_to_array;
+BufferDeleter elgamal_free_buffer = &gcrypt_elgamal_free_buffer;
 ArrayToElement elgamal_array_to_element = &gcrypt_elgamal_array_to_element;
 GroupElementGetter elgamal_get_group_element = &gcrypt_elgamal_get_group_element;
 GroupElementDeleter elgamal_delete_group_element = &gcrypt_elgamal_delete_group_element;
diff --git a/node/node.cpp b/node/node.cpp
index f5c8dbe..2e5fd32 100644
--- a/node/node.cpp
+++ b/node/node.cpp
@@ -93,7 +93,8 @@ void Node::handle_node_initialization(const cmix_proto::Initialization& init)
 		
 		api.element_to_array(&data, &len, network_key);
 		sec.set_secret_key(data, len);
-		free(data);
+		
+		api.free_buffer(data);
 		
 		next_node.async_send(sec);
 	} else {
@@ -104,7 +105,7 @@ void Node::handle_node_initialization(const cmix_proto::Initialization& init)
 		
 		cmix_proto::Initialization init;
 		init.set_public_share(buffer, len);
-		free(buffer);
+		api.free_buffer(buffer);
 		
 		BOOST_LOG_TRIVIAL(trace) << "Sending intialization";
 		next_node.async_send(init);
@@ -156,11 +157,11 @@ void Node::handle_node_prepre(cmix_proto::PrePre const& pre) {
 			
 			api.element_to_array(&buffer, &len, new_random_element);
 			prepre.add_r_er(buffer, len);
-			free(buffer);
+			api.free_buffer(buffer);
 			
 			api.element_to_array(&buffer, &len, new_message_element);
 			prepre.add_m_er(buffer, len);
-			free(buffer);
+			api.free_buffer(buffer);
 			
 			api.free_group_element(random_element);
 			api.free_group_element(message_element);
@@ -224,11 +225,11 @@ void Node::handle_client_keyexchange(ClientConnections::key_type handle, cmix_pr
 	
 	api.element_to_array(&buffer, &len, keypair.pub);
 	exchange.set_public_key(buffer, len);
-	free(buffer);
+	api.free_buffer(buffer);
 	
 	api.element_to_array(&buffer, &len, ex_val);
 	exchange.set_value(buffer, len);
-	free(buffer);
+	api.free_buffer(buffer);
 	
 	api.free_group_element(ex_val);
 	
@@ -339,15 +340,14 @@ void Node::start_precomputation() {
 		
 		api.element_to_array(&buffer, &len, random_element);
 		prepre.add_m_er(buffer, len);
-		free(buffer);
+		api.free_buffer(buffer);
 		
 		api.element_to_array(&buffer, &len, message_element);
 		prepre.add_m_er(buffer, len);
-		free(buffer);
+		api.free_buffer(buffer);
 		
 		next_node.async_send(prepre);
 		
-		//ToDo generate permutation.
 		precomputation_data.emplace_back(MixData{r, s, pair.first, *perm_it++});
 		
 		api.free_group_element(random_element);