add hacl_get_blake2_info to extract static BLAKE-2 information

- use this new helper in `py_blake2b_get_digest_size`
- in the future, exposing `key_length` will be easier

Author: picnixz

Modules/blake2module.c

@@ -918,29 +918,37 @@ py_blake2b_get_block_size(PyObject *op, void *Py_UNUSED(closure))
 }
 
 
-static PyObject *
-py_blake2b_get_digest_size(PyObject *op, void *Py_UNUSED(closure))
+static Hacl_Hash_Blake2b_index
+hacl_get_blake2_info(Blake2Object *self)
 {
-    Blake2Object *self = _Blake2Object_CAST(op);
     switch (self->impl) {
 #if HACL_CAN_COMPILE_SIMD256
         case Blake2b_256:
-            return PyLong_FromLong(Hacl_Hash_Blake2b_Simd256_info(self->blake2b_256_state).digest_length);
+            return Hacl_Hash_Blake2b_Simd256_info(self->blake2b_256_state);
 #endif
 #if HACL_CAN_COMPILE_SIMD128
         case Blake2s_128:
-            return PyLong_FromLong(Hacl_Hash_Blake2s_Simd128_info(self->blake2s_128_state).digest_length);
+            return Hacl_Hash_Blake2s_Simd128_info(self->blake2s_128_state);
 #endif
         case Blake2b:
-            return PyLong_FromLong(Hacl_Hash_Blake2b_info(self->blake2b_state).digest_length);
+            return Hacl_Hash_Blake2b_info(self->blake2b_state);
         case Blake2s:
-            return PyLong_FromLong(Hacl_Hash_Blake2s_info(self->blake2s_state).digest_length);
+            return Hacl_Hash_Blake2s_info(self->blake2s_state);
         default:
             Py_UNREACHABLE();
     }
 }
 
 
+static PyObject *
+py_blake2b_get_digest_size(PyObject *op, void *Py_UNUSED(closure))
+{
+    Blake2Object *self = _Blake2Object_CAST(op);
+    Hacl_Hash_Blake2b_index info = hacl_get_blake2_info(self);
+    return PyLong_FromLong(info.digest_length);
+}
+
+
 static PyGetSetDef py_blake2b_getsetters[] = {
     {"name", py_blake2b_get_name, NULL, NULL, NULL},
     {"block_size", py_blake2b_get_block_size, NULL, NULL, NULL},