Adds libgcrypt implementation for elgamal in multiplicative group.

Also adapts the API to both handle sodium and gcrypt libraries.

4 files changed, 73 insertions, 33 deletions

diff --git a/libcmix-crypto/curve25519/curve25519.c b/libcmix-crypto/curve25519/curve25519.c
index 4d53ddf..c4fae8d 100644
--- a/libcmix-crypto/curve25519/curve25519.c
+++ b/libcmix-crypto/curve25519/curve25519.c
@@ -3,11 +3,16 @@
 
 struct Api get_curve25519_implementation()
 {
+	curve25519_initialize();
 	return (struct Api) {
+		&curve25519_initialize,
 		&curve25519_create_keypair,
 		&curve25519_keypair_deleter,
+		&curve25519_get_key_array,
+		&curve25519_add_public_share,
 		&curve25519_derive_shared_key,
-		&curve25519_shared_key_deleter
+		&curve25519_shared_key_deleter,
+		&curve25519_deinitialize
 	};
 }
 
diff --git a/libcmix-crypto/curve25519/curve25519.h b/libcmix-crypto/curve25519/curve25519.h
index fde317a..5d004cf 100644
--- a/libcmix-crypto/curve25519/curve25519.h
+++ b/libcmix-crypto/curve25519/curve25519.h
@@ -11,15 +11,38 @@ extern "C" {
  */
 
 /*!
+ * \brief curve25519_initialize initilalize curve25519 library
+ */
+extern void curve25519_initialize(void);
+
+/*!
  * \brief curve25519_create_keypair
  * \return A curve25519 keypair.
  */
-extern struct KeyPair curve25519_create_keypair();
+extern struct KeyPair curve25519_create_keypair(void);
+
 /*!
  * \brief curve25519_keypair_deleter
  * \param p The keypair to free.
  */
-extern void curve25519_keypair_deleter(struct KeyPair p);
+extern void curve25519_keypair_deleter(struct KeyPair* p);
+
+/*!
+ * \brief curve25519_get_pubkey_array
+ * \param pubkey
+ * \param buffer
+ * \param len
+ */
+extern void curve25519_get_key_array(char** buffer, size_t* len, void* pubkey);
+
+/*!
+ * \brief curve25519_add_public_share
+ * \param buffer
+ * \param out_len
+ * \param share
+ * \param pubkey
+ */
+extern void curve25519_add_public_share(char** buffer, size_t* out_len, char const* share, size_t in_len, void* pubkey);
 
 /*!
  * \brief curve25519_derive_shared_key
@@ -28,12 +51,15 @@ extern void curve25519_keypair_deleter(struct KeyPair p);
  * \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* pub_key, bool swap_pub_order);
+extern struct SharedKey curve25519_derive_shared_key(struct KeyPair pair, void const* pub_key, bool swap_pub_order);
+
 /*!
  * \brief curve25519_shared_key_deleter
  * \param s the Shared key to free.
  */
-extern void curve25519_shared_key_deleter(struct SharedKey s);
+extern void curve25519_shared_key_deleter(struct SharedKey* s);
+
+extern void curve25519_deinitialize(void);
 
 /*!
  * \brief get_curve25519_implementation
diff --git a/libcmix-crypto/curve25519/null/null_curve25519.c b/libcmix-crypto/curve25519/null/null_curve25519.c
index 63280ec..33fb963 100644
--- a/libcmix-crypto/curve25519/null/null_curve25519.c
+++ b/libcmix-crypto/curve25519/null/null_curve25519.c
@@ -4,22 +4,28 @@
 #include <stddef.h>
 #include <stdbool.h>
 
-void curve25519_keypair_deleter(struct KeyPair p) {}
+void curve25519_initialize(void){}
 
-struct KeyPair curve25519_create_keypair() {
+struct KeyPair curve25519_create_keypair(void) {
 	return (struct KeyPair){
 		NULL,
 		NULL,
-		0,
-		0
 	};
 }
 
-void curve25519_shared_key_deleter(struct SharedKey s) {}
+void curve25519_keypair_deleter(struct KeyPair* p) {}
+
+void curve25519_get_key_array(char** buffer, size_t* len, void* key) {}
+
+void curve25519_add_public_share(char** buffer, size_t* len_out, char const* share, size_t in_len, void* pubkey) {}
+
+void curve25519_shared_key_deleter(struct SharedKey* s) {}
+
 
 struct SharedKey curve25519_derive_shared_key(struct KeyPair pair, unsigned char const* pub_key, bool swap_pub_order) {
 	return (struct SharedKey){
 		NULL,
-		0
 	};
 }
+
+void curve25519_deinitialize(void){}
\ No newline at end of file
diff --git a/libcmix-crypto/curve25519/sodium/libsodium_curve25519.c b/libcmix-crypto/curve25519/sodium/libsodium_curve25519.c
index e86ec09..06453c5 100644
--- a/libcmix-crypto/curve25519/sodium/libsodium_curve25519.c
+++ b/libcmix-crypto/curve25519/sodium/libsodium_curve25519.c
@@ -6,23 +6,21 @@
 #include <stddef.h>
 #include <stdlib.h>
 
-void init() {
+void curve25519_initialize(void) {
 	if(sodium_init() == -1) {
 		exit(-1);
 	}
 }
 
-void curve25519_keypair_deleter(struct KeyPair p) {
-	sodium_free(p.sec);
-	free(p.pub);
+void curve25519_keypair_deleter(struct KeyPair* p) {
+	sodium_free(p->sec);
+	free(p->pub);
 
-	p.sec = NULL;
-	p.pub = NULL;
+	p->sec = NULL;
+	p->pub = NULL;
 }
 
-struct KeyPair curve25519_create_keypair() {
-	init();
-
+struct KeyPair curve25519_create_keypair(void) {
 	unsigned char* sec = (unsigned char*) sodium_malloc(crypto_box_SECRETKEYBYTES);
 	unsigned char* pub = (unsigned char*) malloc(crypto_box_PUBLICKEYBYTES);
 
@@ -32,38 +30,42 @@ struct KeyPair curve25519_create_keypair() {
 	return (struct KeyPair){
 		sec,
 		pub,
-		crypto_box_SECRETKEYBYTES,
-		crypto_box_PUBLICKEYBYTES
 	};
 }
 
-void curve25519_shared_key_deleter(struct SharedKey s) {
-	sodium_free(s.shared);
+void curve25519_shared_key_deleter(struct SharedKey* s) {
+	sodium_free(s->shared);
+
+	s->shared = NULL;
+}
+
+void curve25519_get_key_array(char** buffer, size_t* len, void* key) {
 
-	s.shared = NULL;
 }
 
-struct SharedKey curve25519_derive_shared_key(struct KeyPair pair, unsigned char const* pub_key, bool swap_pub_order) {
-	init();
+void curve25519_add_public_share(char** buffer, size_t* out_len, char const* share, size_t in_len, void* pubkey) {
 
+}
+
+struct SharedKey curve25519_derive_shared_key(struct KeyPair pair, void const* pub_key, bool swap_pub_order) {
 	unsigned char* shared = (unsigned char*) sodium_malloc(crypto_generichash_BYTES);
 
 	crypto_generichash_state h;
 
 	unsigned char* scalarmult_q = (unsigned char*) sodium_malloc(crypto_scalarmult_BYTES);
 
-	if (crypto_scalarmult(scalarmult_q, pair.sec, pub_key) != 0) {
+	if (crypto_scalarmult(scalarmult_q, (unsigned char const*) pair.sec, (unsigned char const*) pub_key) != 0) {
 		exit(-1);
 	}
 
 	crypto_generichash_init(&h, NULL, 0U, crypto_generichash_BYTES);
 	crypto_generichash_update(&h, scalarmult_q, crypto_scalarmult_BYTES);
 	if(swap_pub_order) {
-		crypto_generichash_update(&h, pub_key, crypto_box_PUBLICKEYBYTES);
-		crypto_generichash_update(&h, pair.pub, crypto_box_PUBLICKEYBYTES);
+		crypto_generichash_update(&h, (unsigned char const*) pub_key, crypto_box_PUBLICKEYBYTES);
+		crypto_generichash_update(&h, (unsigned char const*) pair.pub, crypto_box_PUBLICKEYBYTES);
 	} else {
-		crypto_generichash_update(&h, pair.pub, crypto_box_PUBLICKEYBYTES);
-		crypto_generichash_update(&h, pub_key, crypto_box_PUBLICKEYBYTES);
+		crypto_generichash_update(&h, (unsigned char const*) pair.pub, crypto_box_PUBLICKEYBYTES);
+		crypto_generichash_update(&h, (unsigned char const*) pub_key, crypto_box_PUBLICKEYBYTES);
 	}
 	crypto_generichash_final(&h, shared, crypto_generichash_BYTES);
 
@@ -71,7 +73,8 @@ struct SharedKey curve25519_derive_shared_key(struct KeyPair pair, unsigned char
 
 	return (struct SharedKey){
 		shared,
-		crypto_generichash_BYTES
 	};
 }
 
+void curve25519_deinitialize(void) {}
+