From aa2c69529a3de5bcc550e4123542796e6e10f980 Mon Sep 17 00:00:00 2001
From: Jesper Louis Andersen <jesper.louis.andersen@gmail.com>
Date: Tue, 4 Feb 2020 12:59:18 +0100
Subject: [PATCH] Streamlines generichashThe multi-part hash API is
 nowreflecting the same crypto modulefunctions in style. This is easierto use
 for people, I believe.

---
 CHANGELOG.md        |  7 ++++++-
 c_src/generichash.c | 23 ++++++++++-------------
 src/enacl.erl       |  9 ++++++++-
 3 files changed, 24 insertions(+), 15 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index a79fe7e..43e395c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,7 +11,6 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
   Pretty large change, but OTOH, this ought to happen before a 1.0 release as well.
   - AEAD
   - enacl
-  - generichash
   - hash
   - kx
   - pwhash
@@ -19,6 +18,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
   - secret
   - sign
 
+- Implement missing EQC tests
+  - Generichash
+  - Multi-part generic hash
+
 ## [Unreleased]
 
 ### Compatibility
@@ -71,6 +74,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Renamed many routines from enif_* to enacl_*. This better reflects where they live
   in the code base, and avoids pollution of the enif_* "namespace".
 - Split Sign Public Key routines from the rest. Modernize the handling of contexts.
+- The multi-part generic hash routines now follow the structure of the crypto
+  modules multi-part constructions in API and style.
 
 ### Fixed
 - Fix a resource leak in generichash/sign init/update/final.
diff --git a/c_src/generichash.c b/c_src/generichash.c
index 524def8..05794bc 100644
--- a/c_src/generichash.c
+++ b/c_src/generichash.c
@@ -157,8 +157,7 @@ ERL_NIF_TERM enacl_crypto_generichash_init(ErlNifEnv *env, int argc,
   // Verify that hash size is valid
   if ((hash_size <= crypto_generichash_BYTES_MIN) ||
       (hash_size >= crypto_generichash_BYTES_MAX)) {
-    ret = enacl_error_tuple(env, "invalid_hash_size");
-    goto done;
+    goto bad_arg;
   }
 
   // validate key size
@@ -167,8 +166,7 @@ ERL_NIF_TERM enacl_crypto_generichash_init(ErlNifEnv *env, int argc,
     k = NULL;
   } else if (key.size <= crypto_generichash_KEYBYTES_MIN ||
              key.size >= crypto_generichash_KEYBYTES_MAX) {
-    ret = enacl_error_tuple(env, "invalid_key_size");
-    goto done;
+    goto bad_arg;
   }
 
   // Create the resource
@@ -210,7 +208,7 @@ ERL_NIF_TERM enacl_crypto_generichash_init(ErlNifEnv *env, int argc,
 bad_arg:
   return enif_make_badarg(env);
 err:
-  ret = enacl_error_tuple(env, "internal_error");
+  ret = enif_make_atom(env, "notsup");
   if (obj != NULL) {
     if (obj->alive) {
       sodium_free(obj->ctx);
@@ -244,14 +242,12 @@ ERL_NIF_TERM enacl_crypto_generichash_update(ErlNifEnv *env, int argc,
   enif_mutex_lock(obj->mtx);
 
   if (!obj->alive) {
-    ret = enacl_error_tuple(env, "finalized");
-    goto done;
+    goto err;
   }
 
   // Update hash state
   if (0 != crypto_generichash_update(obj->ctx, data.data, data.size)) {
-    ret = enacl_error_tuple(env, "hash_update_error");
-    goto done;
+    goto err;
   }
 
   ret = argv[0];
@@ -259,6 +255,8 @@ ERL_NIF_TERM enacl_crypto_generichash_update(ErlNifEnv *env, int argc,
 
 bad_arg:
   return enif_make_badarg(env);
+err:
+  ret = enif_make_badarg(env);
 done:
   enif_mutex_unlock(obj->mtx);
   return ret;
@@ -278,17 +276,14 @@ ERL_NIF_TERM enacl_crypto_generichash_final(ErlNifEnv *env, int argc,
 
   enif_mutex_lock(obj->mtx);
   if (!obj->alive) {
-    ret = enacl_error_tuple(env, "finalized");
-    goto done;
+    goto err;
   }
 
   if (!enif_alloc_binary(obj->outlen, &hash)) {
-    ret = enacl_error_tuple(env, "alloc_failed");
     goto done;
   }
 
   if (0 != crypto_generichash_final(obj->ctx, hash.data, hash.size)) {
-    ret = enacl_error_tuple(env, "hash_error");
     goto release;
   }
 
@@ -305,6 +300,8 @@ ERL_NIF_TERM enacl_crypto_generichash_final(ErlNifEnv *env, int argc,
 
 bad_arg:
   return enif_make_badarg(env);
+err:
+  ret = enif_make_badarg(env);
 release:
   enif_release_binary(&hash);
 done:
diff --git a/src/enacl.erl b/src/enacl.erl
index 037bafb..4ee0e73 100644
--- a/src/enacl.erl
+++ b/src/enacl.erl
@@ -351,16 +351,23 @@ generichash(HashSize, Message, Key) ->
 generichash(HashSize, Message) ->
     enacl_nif:crypto_generichash(HashSize, Message, <<>>).
 
+%% @doc generichash_init/2 initializes a multi-part hash.
+%% @end
+-spec generichash_init(generichash_bytes(), binary()) -> reference() | notsup.
 generichash_init(HashSize, Key) ->
     enacl_nif:crypto_generichash_init(HashSize, Key).
 
+%% @doc generichash_update/2 updates a multi-part hash with new data.
+%% @end
+-spec generichash_update(reference(), iodata()) -> reference().
 generichash_update(State, Message) ->
     enacl_nif:crypto_generichash_update(State, Message).
 
+%% @doc generichash_final/1 finalizes a multi-part hash.
+-spec generichash_final(reference()) -> binary().
 generichash_final(State) ->
     enacl_nif:crypto_generichash_final(State).
 
-
 -type pwhash_limit() :: interactive | moderate | sensitive | pos_integer().
 %% @doc pwhash/2 hash a password
 %%