Merge pull request #288 from github/hmac-barrier-guard-checks

Make barrier guards more specific

ql/test/library-tests/dataflow/barrier-guards/barrier-guards.expected

@@ -0,0 +1,5 @@
+| barrier-guards.rb:3:4:3:15 | ... == ... | barrier-guards.rb:4:5:4:7 | foo | barrier-guards.rb:3:4:3:6 | foo | true |
+| barrier-guards.rb:9:4:9:24 | call to include? | barrier-guards.rb:10:5:10:7 | foo | barrier-guards.rb:9:21:9:23 | foo | true |
+| barrier-guards.rb:15:4:15:15 | ... != ... | barrier-guards.rb:18:5:18:7 | foo | barrier-guards.rb:15:4:15:6 | foo | false |
+| barrier-guards.rb:21:8:21:19 | ... == ... | barrier-guards.rb:24:5:24:7 | foo | barrier-guards.rb:21:8:21:10 | foo | true |
+| barrier-guards.rb:27:8:27:19 | ... != ... | barrier-guards.rb:28:5:28:7 | foo | barrier-guards.rb:27:8:27:10 | foo | false |

ql/test/library-tests/dataflow/barrier-guards/barrier-guards.ql

@@ -0,0 +1,7 @@
+import codeql.ruby.dataflow.internal.DataFlowPublic
+import codeql.ruby.dataflow.BarrierGuards
+import codeql.ruby.controlflow.CfgNodes
+
+from BarrierGuard g, boolean branch, ExprCfgNode expr
+where g.checks(expr, branch)
+select g, g.getAGuardedNode(), expr, branch

ql/test/library-tests/dataflow/barrier-guards/barrier-guards.rb

@@ -0,0 +1,33 @@
+foo = "foo"
+
+if foo == "foo"
+    foo
+else
+    foo
+end
+
+if ["foo"].include?(foo)
+    foo
+else
+    foo
+end
+
+if foo != "foo"
+    foo
+else
+    foo
+end
+
+unless foo == "foo"
+    foo
+else
+    foo
+end
+
+unless foo != "foo"
+    foo
+else
+    foo
+end
+
+foo

ql/test/query-tests/security/cwe-089/ActiveRecordInjection.rb

@@ -71,8 +71,15 @@ class BarController < ApplicationController
   def safe_paths
     dir = params[:order]
     # GOOD: barrier guard prevents taint flow
-    dir = "DESC" unless dir == "ASC"
-    User.order("name #{dir}")
+    if dir == "ASC"
+      User.order("name #{dir}")
+    else
+      dir = "DESC"
+      User.order("name #{dir}")
+    end
+    # TODO: a more idiomatic form of this guard is the following:
+    #     dir = "DESC" unless dir == "ASC"
+    # but our taint tracking can't (yet) handle that properly
 
     name = params[:user_name]
     # GOOD: barrier guard prevents taint flow

ql/test/query-tests/security/cwe-089/SqlInjection.expected

@@ -12,8 +12,8 @@ edges
 | ActiveRecordInjection.rb:56:38:56:43 | call to params :  | ActiveRecordInjection.rb:56:38:56:50 | ...[...] :  |
 | ActiveRecordInjection.rb:56:38:56:50 | ...[...] :  | ActiveRecordInjection.rb:8:31:8:34 | pass :  |
 | ActiveRecordInjection.rb:62:10:62:15 | call to params :  | ActiveRecordInjection.rb:68:21:68:33 | ... + ... |
-| ActiveRecordInjection.rb:94:22:94:27 | call to params :  | ActiveRecordInjection.rb:94:22:94:45 | ...[...] :  |
-| ActiveRecordInjection.rb:94:22:94:45 | ...[...] :  | ActiveRecordInjection.rb:20:23:20:31 | condition :  |
+| ActiveRecordInjection.rb:101:22:101:27 | call to params :  | ActiveRecordInjection.rb:101:22:101:45 | ...[...] :  |
+| ActiveRecordInjection.rb:101:22:101:45 | ...[...] :  | ActiveRecordInjection.rb:20:23:20:31 | condition :  |
 nodes
 | ActiveRecordInjection.rb:8:25:8:28 | name :  | semmle.label | name :  |
 | ActiveRecordInjection.rb:8:31:8:34 | pass :  | semmle.label | pass :  |
@@ -36,12 +36,12 @@ nodes
 | ActiveRecordInjection.rb:56:38:56:50 | ...[...] :  | semmle.label | ...[...] :  |
 | ActiveRecordInjection.rb:62:10:62:15 | call to params :  | semmle.label | call to params :  |
 | ActiveRecordInjection.rb:68:21:68:33 | ... + ... | semmle.label | ... + ... |
-| ActiveRecordInjection.rb:94:22:94:27 | call to params :  | semmle.label | call to params :  |
-| ActiveRecordInjection.rb:94:22:94:45 | ...[...] :  | semmle.label | ...[...] :  |
+| ActiveRecordInjection.rb:101:22:101:27 | call to params :  | semmle.label | call to params :  |
+| ActiveRecordInjection.rb:101:22:101:45 | ...[...] :  | semmle.label | ...[...] :  |
 #select
 | ActiveRecordInjection.rb:10:33:10:67 | "name='#{...}' and pass='#{...}'" | ActiveRecordInjection.rb:56:23:56:28 | call to params :  | ActiveRecordInjection.rb:10:33:10:67 | "name='#{...}' and pass='#{...}'" | This SQL query depends on $@. | ActiveRecordInjection.rb:56:23:56:28 | call to params | a user-provided value |
 | ActiveRecordInjection.rb:10:33:10:67 | "name='#{...}' and pass='#{...}'" | ActiveRecordInjection.rb:56:38:56:43 | call to params :  | ActiveRecordInjection.rb:10:33:10:67 | "name='#{...}' and pass='#{...}'" | This SQL query depends on $@. | ActiveRecordInjection.rb:56:38:56:43 | call to params | a user-provided value |
-| ActiveRecordInjection.rb:23:17:23:25 | condition | ActiveRecordInjection.rb:94:22:94:27 | call to params :  | ActiveRecordInjection.rb:23:17:23:25 | condition | This SQL query depends on $@. | ActiveRecordInjection.rb:94:22:94:27 | call to params | a user-provided value |
+| ActiveRecordInjection.rb:23:17:23:25 | condition | ActiveRecordInjection.rb:101:22:101:27 | call to params :  | ActiveRecordInjection.rb:23:17:23:25 | condition | This SQL query depends on $@. | ActiveRecordInjection.rb:101:22:101:27 | call to params | a user-provided value |
 | ActiveRecordInjection.rb:35:30:35:44 | ...[...] | ActiveRecordInjection.rb:35:30:35:35 | call to params :  | ActiveRecordInjection.rb:35:30:35:44 | ...[...] | This SQL query depends on $@. | ActiveRecordInjection.rb:35:30:35:35 | call to params | a user-provided value |
 | ActiveRecordInjection.rb:39:21:39:43 | "id = '#{...}'" | ActiveRecordInjection.rb:39:30:39:35 | call to params :  | ActiveRecordInjection.rb:39:21:39:43 | "id = '#{...}'" | This SQL query depends on $@. | ActiveRecordInjection.rb:39:30:39:35 | call to params | a user-provided value |
 | ActiveRecordInjection.rb:43:23:43:45 | "id = '#{...}'" | ActiveRecordInjection.rb:43:32:43:37 | call to params :  | ActiveRecordInjection.rb:43:23:43:45 | "id = '#{...}'" | This SQL query depends on $@. | ActiveRecordInjection.rb:43:32:43:37 | call to params | a user-provided value |