7 files changed, 41 insertions, 32 deletions
diff --git a/libcmix-crypto/api.h b/libcmix-crypto/api.h
index 8c40d23..6d701d7 100644
--- a/libcmix-crypto/api.h
+++ b/libcmix-crypto/api.h
@@ -32,7 +32,7 @@ typedef void (*KeyPairDeleter)(struct KeyPair*);
  * \brief Defines how a Derived Shared Key function should look like.
  *        Used to store a pointer to function to a implementation.
  */
-typedef struct SharedKey (*SharedKeyDeriver)(struct KeyPair, unsigned char const*, size_t, unsigned char const*, size_t, GroupElement, bool);
+typedef GroupElement (*SharedKeyDeriver)(struct KeyPair, unsigned char const*, size_t, unsigned char const*, size_t, GroupElement, bool);
 
 /*!
  * \brief Defines how a Derived Shared Key deleter function should look like.
@@ -63,7 +63,7 @@ typedef GroupElement(*ArrayToElement)(char const*, size_t size, bool);
 /*!
  * \brief PublicShareAdder typedef
  */
-typedef void(*PublicShareAdder)(char**, size_t*, char const*, size_t, GroupElement);
+typedef void(*PublicShareAdder)(GroupElement*, char const*, size_t, GroupElement);
 
 /*!
  *
@@ -83,6 +83,11 @@ typedef GroupElement(*GroupElementMultiplier)(GroupElement, GroupElement, bool);
 /*!
  *
  */
+typedef size_t(*GroupElementArraySizeGetter)();
+
+/*!
+ *
+ */
 typedef void(*GroupElementDeleter)(GroupElement);
 
 /*!
@@ -95,12 +100,13 @@ typedef void (*Encrypter)(GroupElement*, GroupElement*, GroupElement, GroupEleme
  */
 struct Api {
 	Initializer initialize; ///< Function that will initialize the crypto library.
-	KeyPairCreator create_key_pair; ///< Pointer to keypair creation function
-	KeyPairDeleter free_key_pair; ///< Pointer to keypair deletor function
+	KeyPairCreator create_keypair; ///< Pointer to keypair creation function
+	KeyPairDeleter free_keypair; ///< 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
+	GroupElementArraySizeGetter get_group_element_array_size; ///< Return the size required to store a groupelement in an array;
 	GroupElementDeleter free_group_element; ///< frees a base type of the cryptolibrary.
 	KeyExchangeValueGetter get_key_exchange_value; ///< get generator *op* group element.
 	GroupElementMultiplier multiply; ///< Multiplies two groupelements modulo group.
diff --git a/libcmix-crypto/curve25519/curve25519.c b/libcmix-crypto/curve25519/curve25519.c
index 6eaaafc..db77d9a 100644
--- a/libcmix-crypto/curve25519/curve25519.c
+++ b/libcmix-crypto/curve25519/curve25519.c
@@ -15,6 +15,7 @@ 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/curve25519/curve25519.h b/libcmix-crypto/curve25519/curve25519.h
index 9b65d4e..762e8db 100644
--- a/libcmix-crypto/curve25519/curve25519.h
+++ b/libcmix-crypto/curve25519/curve25519.h
@@ -51,7 +51,7 @@ extern void curve25519_add_public_share(char** buffer, size_t* out_len, char con
  * \param swap_pub_order Should we swap the order in which we feed the public keys to the hash function.
  * \return A Shared key
  */
-extern struct SharedKey curve25519_derive_shared_key(struct KeyPair pair, unsigned char const* other_pub, size_t pub_len, unsigned char const* value, size_t value_len, void* priv_value, bool swap_pub_order);
+extern GroupElement curve25519_derive_shared_key(struct KeyPair pair, unsigned char const* other_pub, size_t pub_len, unsigned char const* value, size_t value_len, void* priv_value, bool swap_pub_order);
 /*!
  * \brief curve25519_shared_key_deleter
  * \param s the Shared key to free.
diff --git a/libcmix-crypto/curve25519/sodium/libsodium_curve25519.c b/libcmix-crypto/curve25519/sodium/libsodium_curve25519.c
index 6c3fe13..2405442 100644
--- a/libcmix-crypto/curve25519/sodium/libsodium_curve25519.c
+++ b/libcmix-crypto/curve25519/sodium/libsodium_curve25519.c
@@ -47,7 +47,7 @@ void curve25519_add_public_share(char** buffer, size_t* out_len, char const* sha
 
 }
 
-struct SharedKey curve25519_derive_shared_key(struct KeyPair pair, unsigned char const* other_pub, size_t pub_len, unsigned char const* value, size_t value_len, void* priv_value, bool swap_pub_order) {
+GroupElement curve25519_derive_shared_key(struct KeyPair pair, unsigned char const* other_pub, size_t pub_len, unsigned char const* value, size_t value_len, void* priv_value, bool swap_pub_order) {
 	unsigned char* shared = (unsigned char*) sodium_malloc(crypto_generichash_BYTES);
 
 	crypto_generichash_state h;
@@ -71,9 +71,7 @@ struct SharedKey curve25519_derive_shared_key(struct KeyPair pair, unsigned char
 
 	sodium_free(scalarmult_q);
 
-	return (struct SharedKey){
-		shared,
-	};
+	return shared;
 }
 
 void curve25519_deinitialize(void) {}
diff --git a/libcmix-crypto/elgamal/elgamal.c b/libcmix-crypto/elgamal/elgamal.c
index 336d974..e54f76d 100644
--- a/libcmix-crypto/elgamal/elgamal.c
+++ b/libcmix-crypto/elgamal/elgamal.c
@@ -4,21 +4,22 @@ struct Api get_elgamal_implementation()
 {
 	elgamal_initialize();
 	return (struct Api) {
-		elgamal_initialize,
-		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,
-		elgamal_get_key_exchange_value,
-		elgamal_multiply,
-		elgamal_add_public_share,
-		elgamal_derive_shared_key,
-		elgamal_delete_shared_key,
-		elgamal_encrypt,
-		elgamal_deinitialize
+		.initialize = elgamal_initialize,
+		.create_keypair = elgamal_create_keypair,
+		.free_keypair = elgamal_delete_keypair,
+		.element_to_array = elgamal_element_to_array,
+		.free_buffer = elgamal_free_buffer,
+		.array_to_element = elgamal_array_to_element,
+		.get_group_element = elgamal_get_group_element,
+		.get_group_element_array_size = elgamal_get_group_element_array_size,
+		.free_group_element = elgamal_delete_group_element,
+		.get_key_exchange_value = elgamal_get_key_exchange_value,
+		.multiply = elgamal_multiply,
+		.add_public_share = elgamal_add_public_share,
+		.derive_shared_key = elgamal_derive_shared_key,
+		.free_shared_key = elgamal_delete_shared_key,
+		.encrypt = elgamal_encrypt,
+		.deinitialize = elgamal_deinitialize
 	};
 }
 
diff --git a/libcmix-crypto/elgamal/elgamal.h b/libcmix-crypto/elgamal/elgamal.h
index 71046c5..43ddca0 100644
--- a/libcmix-crypto/elgamal/elgamal.h
+++ b/libcmix-crypto/elgamal/elgamal.h
@@ -30,6 +30,8 @@ extern KeyExchangeValueGetter elgamal_get_key_exchange_value;
 
 extern GroupElementMultiplier elgamal_multiply;
 
+extern GroupElementArraySizeGetter elgamal_get_group_element_array_size;
+
 extern PublicShareAdder elgamal_add_public_share;
 
 extern SharedKeyDeriver elgamal_derive_shared_key;
diff --git a/libcmix-crypto/elgamal/gcrypt/gcrypt_elgamal.c b/libcmix-crypto/elgamal/gcrypt/gcrypt_elgamal.c
index a0512dd..c610556 100644
--- a/libcmix-crypto/elgamal/gcrypt/gcrypt_elgamal.c
+++ b/libcmix-crypto/elgamal/gcrypt/gcrypt_elgamal.c
@@ -152,11 +152,15 @@ GroupElement gcrypt_elgamal_multiply(GroupElement lh, GroupElement rh, bool secu
 	return ret;
 }
 
+size_t gcrypt_elgamal_get_group_element_array_size() {
+	return 256u;
+}
+
 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) {
+void gcrypt_elgamal_add_public_share(GroupElement* el, char const* share, size_t in_len, void* pubkey) {
 	
 	gcry_error_t error;
 	size_t parse_error_pos;
@@ -170,14 +174,12 @@ void gcrypt_elgamal_add_public_share(char** buffer, size_t* out_len, char const*
 	gcry_mpi_t result = gcry_mpi_new(0);
 	gcry_mpi_mulm(result, mpi_share, y, p);
 	
-	error = gcry_mpi_aprint(GCRYMPI_FMT_USG, (unsigned char**) buffer, out_len, result);
-	check(error);
+	*el = result;
 	
 	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) {
+GroupElement 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) {
 
 	gcry_error_t error;
 	size_t parse_error_pos;
@@ -192,9 +194,7 @@ struct SharedKey gcrypt_elgamal_derive_shared_key(struct KeyPair keypair, unsign
 
 	gcry_mpi_release(ga);
 
-	return (struct SharedKey){
-		gab
-	};
+	return gab;
 }
 
 void gcrypt_elgamal_delete_shared_key(struct SharedKey* s) {
@@ -241,6 +241,7 @@ GroupElementGetter elgamal_get_group_element = &gcrypt_elgamal_get_group_element
 GroupElementDeleter elgamal_delete_group_element = &gcrypt_elgamal_delete_group_element;
 KeyExchangeValueGetter elgamal_get_key_exchange_value = &gcrypt_elgamal_get_key_exchange_value;
 GroupElementMultiplier elgamal_multiply = &gcrypt_elgamal_multiply;
+GroupElementArraySizeGetter elgamal_get_group_element_array_size = &gcrypt_elgamal_get_group_element_array_size;
 PublicShareAdder elgamal_add_public_share = &gcrypt_elgamal_add_public_share;
 SharedKeyDeriver elgamal_derive_shared_key = &gcrypt_elgamal_derive_shared_key;
 SharedKeyDeleter elgamal_delete_shared_key = &gcrypt_elgamal_delete_shared_key;