Merge pull request #92 from cipherstash/fix-ore-null-comparison

fix(ore): NULL comparisons should return NULL

Author: tobyhede

sql/000-ore.sql

@@ -23,16 +23,8 @@ CREATE FUNCTION compare_ore_64_8_v1_term(a ore_64_8_v1_term, b ore_64_8_v1_term)
 
     indicator smallint := 0;
   BEGIN
-    IF a IS NULL AND b IS NULL THEN
-      RETURN 0;
-    END IF;
-
-    IF a IS NULL THEN
-      RETURN -1;
-    END IF;
-
-    IF b IS NULL THEN
-      RETURN 1;
+    IF a IS NULL OR b IS NULL THEN
+      RETURN NULL;
     END IF;
 
     IF bit_length(a.bytes) != bit_length(b.bytes) THEN
@@ -239,13 +231,19 @@ RETURNS integer AS $$
   DECLARE
     cmp_result integer;
   BEGIN
-    IF (array_length(a, 1) = 0 OR a IS NULL) AND (array_length(b, 1) = 0 OR b IS NULL) THEN
+    IF a IS NULL OR b IS NULL THEN
+      RETURN NULL;
+    END IF;
+
+    IF (array_length(a, 1) = 0) AND (array_length(b, 1) = 0) THEN
       RETURN 0;
     END IF;
-    IF array_length(a, 1) = 0 OR a IS NULL THEN
+
+    IF array_length(a, 1) = 0 THEN
       RETURN -1;
     END IF;
-    IF array_length(b, 1) = 0 OR a IS NULL THEN
+
+    IF array_length(b, 1) = 0 THEN
       RETURN 1;
     END IF;
 

tests/operators-ore.sql

@@ -13,8 +13,6 @@ CREATE TABLE users
 TRUNCATE TABLE users;
 
 
-TRUNCATE TABLE users;
-
 -- User with "LOW" value
 INSERT INTO users (name_encrypted) VALUES (
   '{
@@ -30,6 +28,9 @@ INSERT INTO users (name_encrypted) VALUES (
   }'::jsonb
 );
 
+INSERT INTO users (name_encrypted) VALUES (NULL);
+
+
 -- ORE eq < OPERATORS
 DO $$
   DECLARE
@@ -57,6 +58,10 @@ DO $$
     -- SANITY CHECK
     ASSERT (SELECT EXISTS (SELECT id FROM users WHERE cs_ore_64_8_v1(name_encrypted) < cs_ore_64_8_v1(ore_json)));
 
+    -- ignore null
+    ASSERT (SELECT (SELECT COUNT(*) FROM (SELECT id FROM users WHERE cs_ore_64_8_v1(name_encrypted) < cs_ore_64_8_v1(ore_json)) as count) = 1);
+
+
     ASSERT (SELECT EXISTS (
       SELECT id FROM users WHERE name_encrypted < ore_cs_encrypted::jsonb
     ));