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Merge pull request #407 from diffix/piotr/disallow-select-aid
Reject pointless select/group by AID
2 parents 42c0a2f + fe52376 commit e80721e

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9 files changed

+61
-88
lines changed

9 files changed

+61
-88
lines changed

‎src/query/anonymization.c‎

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Original file line numberDiff line numberDiff line change
@@ -1,6 +1,7 @@
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#include "postgres.h"
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#include "catalog/pg_aggregate.h"
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#include "catalog/pg_class.h"
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#include "catalog/pg_type.h"
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#include "common/shortest_dec.h"
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#include "nodes/makefuncs.h"
@@ -14,6 +15,7 @@
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#include "pg_diffix/aggregation/bucket_scan.h"
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#include "pg_diffix/aggregation/common.h"
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#include "pg_diffix/auth.h"
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#include "pg_diffix/oid_cache.h"
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#include "pg_diffix/query/allowed_objects.h"
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#include "pg_diffix/query/anonymization.h"
@@ -270,6 +272,25 @@ static List *gather_aid_refs(Query *query, List *relations)
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return aid_refs;
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}
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static void reject_aid_grouping(Query *query)
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{
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List *grouping_exprs = get_sortgrouplist_exprs(query->groupClause, query->targetList);
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ListCell *cell;
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foreach (cell, grouping_exprs)
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{
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Node *group_expr = (Node *)lfirst(cell);
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if (IsA(group_expr, Var))
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{
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Var *var = (Var *)group_expr;
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RangeTblEntry *rte = rt_fetch(var->varno, query->rtable);
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if (rte->relkind == RELKIND_RELATION && is_aid_column(rte->relid, var->varattno))
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FAILWITH_LOCATION(var->location, "Selecting or grouping by an AID column will result in a fully censored output.");
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}
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}
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}
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static void append_aid_args(Aggref *aggref, List *aid_refs)
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{
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bool found_any = false;
@@ -584,6 +605,8 @@ static void compile_anonymizing_query(Query *query, List *personal_relations, An
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AnonymizationContext *anon_context = make_query_anonymizing(query, personal_relations);
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608+
reject_aid_grouping(query);
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verify_bucket_expressions(query);
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anon_context->sql_seed = prepare_bucket_seeds(query);

‎test/expected/noiseless.out‎

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@@ -158,29 +158,6 @@ SELECT COUNT(*), COUNT(city), COUNT(DISTINCT city) FROM test_patients;
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----------------------------------------------------------------
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-- LCF & Filtering
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----------------------------------------------------------------
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SELECT id FROM test_customers;
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id
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----
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(18 rows)
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SELECT city FROM test_customers;
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city
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--------

‎test/expected/noisy.out‎

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Original file line numberDiff line numberDiff line change
@@ -150,27 +150,6 @@ SELECT COUNT(*), COUNT(city), COUNT(DISTINCT city) FROM test_patients;
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----------------------------------------------------------------
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-- LCF & Filtering
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----------------------------------------------------------------
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SELECT id FROM test_customers;
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id
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----
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(16 rows)
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SELECT city FROM test_customers;
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city
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------

‎test/expected/star_bucket.out‎

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Original file line numberDiff line numberDiff line change
@@ -128,31 +128,6 @@ GROUP BY 1, 2, 3;
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----------------------------------------------------------------
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-- Other queries
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----------------------------------------------------------------
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SELECT *
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FROM star_bucket;
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id | dept | gender | title
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----+------+--------+-------
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| * | * | *
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| * | * | *
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| * | * | *
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| * | * | *
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| * | * | *
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| * | * | *
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| * | * | *
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| * | * | *
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| * | * | *
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| * | * | *
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| * | * | *
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| * | * | *
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| * | * | *
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| * | * | *
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| * | * | *
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| * | * | *
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| * | * | *
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| * | * | *
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| * | * | *
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(19 rows)
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SELECT dept, gender, title
157132
FROM star_bucket;
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dept | gender | title

‎test/expected/validation.out‎

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@@ -179,25 +179,25 @@ FROM (
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0
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(1 row)
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182-
SELECT COUNT(*), COUNT(x.city), COUNT(DISTINCT x.id)
182+
SELECT COUNT(*), COUNT(x.city), COUNT(DISTINCT x.city)
183183
FROM (
184-
SELECT * FROM test_validation
184+
SELECT name, city, discount, birthday, lunchtime, last_seen FROM test_validation
185185
) x;
186186
count | count | count
187187
-------+-------+-------
188188
0 | 0 | 0
189189
(1 row)
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191-
SELECT COUNT(DISTINCT x.modified_id) FROM ( SELECT id AS modified_id FROM test_validation ) x;
191+
SELECT COUNT(DISTINCT x.modified_name) FROM ( SELECT name AS modified_name FROM test_validation ) x;
192192
count
193193
-------
194194
0
195195
(1 row)
196196

197-
SELECT COUNT(*), COUNT(x.city), COUNT(DISTINCT x.user_id)
197+
SELECT COUNT(*), COUNT(x.city), COUNT(DISTINCT x.user_name)
198198
FROM (
199-
SELECT y.city as city, y.id as user_id
200-
FROM ( SELECT * FROM test_validation ) y
199+
SELECT y.city as city, y.name as user_name
200+
FROM ( SELECT name, city, discount, birthday, lunchtime, last_seen FROM test_validation ) y
201201
) x;
202202
count | count | count
203203
-------+-------+-------
@@ -490,6 +490,25 @@ SELECT count(distinct tableoid) FROM test_validation;
490490
ERROR: [PG_DIFFIX] System columns are not allowed in this context.
491491
LINE 1: SELECT count(distinct tableoid) FROM test_validation;
492492
^
493+
-- Get rejected because of selecting AID columns
494+
SELECT id FROM test_validation;
495+
ERROR: [PG_DIFFIX] Selecting or grouping by an AID column will result in a fully censored output.
496+
LINE 1: SELECT id FROM test_validation;
497+
^
498+
SELECT 1 FROM test_validation GROUP BY id;
499+
ERROR: [PG_DIFFIX] Selecting or grouping by an AID column will result in a fully censored output.
500+
LINE 1: SELECT 1 FROM test_validation GROUP BY id;
501+
^
502+
SELECT * FROM (SELECT id FROM test_validation) z;
503+
ERROR: [PG_DIFFIX] Selecting or grouping by an AID column will result in a fully censored output.
504+
LINE 1: SELECT * FROM (SELECT id FROM test_validation) z;
505+
^
506+
-- Get accepted because of selecting AID with generalization
507+
SELECT diffix.floor_by(id, 2), count(*) FROM test_validation GROUP BY 1;
508+
floor_by | count
509+
----------+-------
510+
(0 rows)
511+
493512
----------------------------------------------------------------
494513
-- Untrusted mode query restrictions
495514
----------------------------------------------------------------

‎test/sql/noiseless.sql‎

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@@ -52,8 +52,6 @@ SELECT COUNT(*), COUNT(city), COUNT(DISTINCT city) FROM test_patients;
5252
-- LCF & Filtering
5353
----------------------------------------------------------------
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55-
SELECT id FROM test_customers;
56-
5755
SELECT city FROM test_customers;
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5957
SELECT city FROM test_customers GROUP BY 1 HAVING length(city) <> 4;

‎test/sql/noisy.sql‎

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Original file line numberDiff line numberDiff line change
@@ -48,8 +48,6 @@ SELECT COUNT(*), COUNT(city), COUNT(DISTINCT city) FROM test_patients;
4848
-- LCF & Filtering
4949
----------------------------------------------------------------
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51-
SELECT id FROM test_customers;
52-
5351
SELECT city FROM test_customers;
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5553
SELECT city FROM test_customers GROUP BY 1 HAVING length(city) <> 4;

‎test/sql/star_bucket.sql‎

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Original file line numberDiff line numberDiff line change
@@ -106,9 +106,6 @@ GROUP BY 1, 2, 3;
106106
-- Other queries
107107
----------------------------------------------------------------
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109-
SELECT *
110-
FROM star_bucket;
111-
112109
SELECT dept, gender, title
113110
FROM star_bucket;
114111

‎test/sql/validation.sql‎

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Original file line numberDiff line numberDiff line change
@@ -112,17 +112,17 @@ FROM (
112112
GROUP BY 1
113113
) x;
114114

115-
SELECT COUNT(*), COUNT(x.city), COUNT(DISTINCT x.id)
115+
SELECT COUNT(*), COUNT(x.city), COUNT(DISTINCT x.city)
116116
FROM (
117-
SELECT * FROM test_validation
117+
SELECT name, city, discount, birthday, lunchtime, last_seen FROM test_validation
118118
) x;
119119

120-
SELECT COUNT(DISTINCT x.modified_id) FROM ( SELECT id AS modified_id FROM test_validation ) x;
120+
SELECT COUNT(DISTINCT x.modified_name) FROM ( SELECT name AS modified_name FROM test_validation ) x;
121121

122-
SELECT COUNT(*), COUNT(x.city), COUNT(DISTINCT x.user_id)
122+
SELECT COUNT(*), COUNT(x.city), COUNT(DISTINCT x.user_name)
123123
FROM (
124-
SELECT y.city as city, y.id as user_id
125-
FROM ( SELECT * FROM test_validation ) y
124+
SELECT y.city as city, y.name as user_name
125+
FROM ( SELECT name, city, discount, birthday, lunchtime, last_seen FROM test_validation ) y
126126
) x;
127127

128128
SELECT * FROM (SELECT name FROM test_validation) x, (SELECT city FROM test_validation) y;
@@ -249,6 +249,13 @@ SELECT count(tableoid) FROM test_validation;
249249
SELECT count(distinct ctid) FROM test_validation;
250250
SELECT count(distinct tableoid) FROM test_validation;
251251

252+
-- Get rejected because of selecting AID columns
253+
SELECT id FROM test_validation;
254+
SELECT 1 FROM test_validation GROUP BY id;
255+
SELECT * FROM (SELECT id FROM test_validation) z;
256+
257+
-- Get accepted because of selecting AID with generalization
258+
SELECT diffix.floor_by(id, 2), count(*) FROM test_validation GROUP BY 1;
252259

253260
----------------------------------------------------------------
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-- Untrusted mode query restrictions

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