Fix C-warnings (#10)

* .envrc is not for git

* Fix c code - avoid warnings

* Bump Erlang versions in Github workflows

c_src/enacl_nif.c

@@ -54,9 +54,8 @@ static int enacl_crypto_upgrade(ErlNifEnv* env, void **priv_data,
     return 0;
 }
 
-static int enacl_crypto_unload(ErlNifEnv* env, void **priv_data,
-                                ERL_NIF_TERM load_info) {
-    return 0;
+static void enacl_crypto_unload(ErlNifEnv* env, void *priv_data) {
+    return;
 }
 
 /* GENERAL ROUTINES

c_src/generichash.c

@@ -221,7 +221,6 @@ ERL_NIF_TERM enacl_crypto_generichash_update(ErlNifEnv *env, int argc,
                                              ERL_NIF_TERM const argv[]) {
   ERL_NIF_TERM ret;
   ErlNifBinary data;
-  unsigned int data_size;
   enacl_generichash_ctx *obj = NULL;
 
   // Validate the arguments

c_src/kdf.c

@@ -20,7 +20,7 @@ ERL_NIF_TERM enacl_crypto_kdf_CONTEXTBYTES(ErlNifEnv *env, int argc,
 ERL_NIF_TERM enacl_crypto_kdf_derive_from_key(ErlNifEnv *env, int argc,
                                               ERL_NIF_TERM const argv[]) {
   ErlNifBinary m, c, r;
-  uint64_t id;
+  ErlNifUInt64 id;
 
   // Validate the arguments
   if ((argc != 3) ||

c_src/public.c

@@ -90,7 +90,7 @@ ERL_NIF_TERM enacl_crypto_box(ErlNifEnv *env, int argc,
     goto bad_arg;
 
   if (!enif_alloc_binary(padded_msg.size, &result)) {
-    goto done;
+    goto err;
   }
 
   if (0 != crypto_box(result.data, padded_msg.data, padded_msg.size, nonce.data,

c_src/secretstream.c

@@ -227,11 +227,13 @@ ERL_NIF_TERM enacl_crypto_secretstream_xchacha20poly1305_init_pull(
   obj->state = enif_alloc(crypto_secretstream_xchacha20poly1305_statebytes());
 
   if (obj->state == NULL) {
+    ret = enacl_internal_error(env);
     goto release;
   }
   obj->alive = 1;
 
   if ((obj->mtx = enif_mutex_create("enacl.secretstream")) == NULL) {
+    ret = enacl_internal_error(env);
     goto free;
   }
 

c_src/sign.c

@@ -62,6 +62,7 @@ ERL_NIF_TERM enacl_crypto_sign_init(ErlNifEnv *env, int argc,
   obj->alive = 0;
   obj->state = enif_alloc(crypto_sign_statebytes());
   if (obj->state == NULL) {
+    ret = enacl_internal_error(env);
     goto release;
   }
   obj->alive = 1;
@@ -82,6 +83,7 @@ ERL_NIF_TERM enacl_crypto_sign_init(ErlNifEnv *env, int argc,
 bad_arg:
   return enif_make_badarg(env);
 free:
+  ret = enacl_internal_error(env);
   if (obj->alive)
     if (obj->state != NULL) {
       sodium_memzero(obj->state, crypto_sign_statebytes());
@@ -285,7 +287,9 @@ enacl_crypto_sign_ed25519_public_to_curve25519(ErlNifEnv *env, int argc,
     return enacl_internal_error(env);
   }
 
-  crypto_sign_ed25519_pk_to_curve25519(curve25519_pk.data, ed25519_pk.data);
+  if (crypto_sign_ed25519_pk_to_curve25519(curve25519_pk.data, ed25519_pk.data) != 0) {
+    return enacl_internal_error(env);
+  }
 
   return enif_make_binary(env, &curve25519_pk);
 }