Added new taint source/sink for iOS

Reviewed By: sblackshear

Differential Revision: D3054009

fbshipit-source-id: 6f6a20a

infer/models/objc/src/NSHTTPCookie.m

@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2015 - present Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+#import <Foundation/NSObject.h>
+#import <Foundation/NSString.h>
+
+@interface NSHTTPCookie : NSObject
+@property(readonly, copy) NSString* value;
+@end
+
+@implementation NSHTTPCookie
+@synthesize value;
+- (NSString*)value {
+  return value;
+}
+@end

infer/models/objc/src/NSString.h

@@ -14,5 +14,9 @@
 }
 
 + (instancetype)stringWithUTF8String:(const char*)bytes;
-
++ (instancetype)stringWithString:(NSString*)aString;
++ (instancetype)stringWithFormat:(NSString*)format, ...;
++ (instancetype)localizedStringWithFormat:(NSString*)format, ...;
+- (instancetype)initWithFormat:(NSString*)format, ...;
+- (instancetype)initWithFormat:(NSString*)format arguments:(va_list)argList;
 @end

infer/models/objc/src/NSString.m

@@ -21,6 +21,20 @@ void __get_array_size(const UInt8);
   return s;
 }
 
++ (instancetype)stringWithString:(NSString*)aString {
+  NSString* s = [NSString alloc];
+  s->value = aString->value;
+  return s;
+}
+
++ (instancetype)stringWithFormat:(NSString*)format, ... {
+  return format;
+}
+
++ (instancetype)localizedStringWithFormat:(NSString*)format, ... {
+  return format;
+}
+
 - (instancetype)initWithBytesNoCopy:(char*)bytes
                              length:(NSUInteger)length
                            encoding:(id)encoding
@@ -33,4 +47,14 @@ void __get_array_size(const UInt8);
   }
   return self;
 }
+
+- (instancetype)initWithFormat:(NSString*)format arguments:(va_list)argList {
+  self->value = format->value;
+  return self;
+}
+
+- (instancetype)initWithFormat:(NSString*)format, ... {
+  self->value = format->value;
+  return self;
+}
 @end

infer/src/backend/tabulation.ml

@@ -805,7 +805,10 @@ let add_tainting_attribute att pvar_param prop =
 
 (* add tainting attributes to a list of paramenters *)
 let add_tainting_att_param_list prop param_nums formal_params att =
-  try
+  match param_nums with
+  | [n] when n<0 -> prop
+  | _ ->
+      try
     IList.map (fun n -> IList.nth formal_params n) param_nums
     |> IList.fold_left (fun prop param -> add_tainting_attribute att param prop) prop
   with Failure _ | Invalid_argument _  ->
@@ -832,6 +835,41 @@ let mk_pre pre formal_params callee_pname callee_attrs =
     |> Prop.expose
   else pre
 
+let report_taint_error e taint_info callee_pname caller_pname calling_prop =
+  let err_desc  =
+    Errdesc.explain_tainted_value_reaching_sensitive_function
+      calling_prop
+      e
+      taint_info
+      callee_pname
+      (State.get_loc ()) in
+  let exn =
+    Exceptions.Tainted_value_reaching_sensitive_function
+      (err_desc, __POS__) in
+  Reporting.log_warning caller_pname exn
+
+let check_taint_on_variadic_function callee_pname caller_pname actual_params calling_prop =
+  let rec n_tail lst n = (* return the tail of a list from element n *)
+    if n = 1 then lst
+    else match lst with
+      | [] -> []
+      | _::lst' -> n_tail lst' (n-1) in
+  let tainted_params = Taint.accepts_sensitive_params callee_pname None in
+  match tainted_params with
+  | [tp] when tp<0 ->
+      (* All actual params from abs(tp) should not be tainted. If we find one we give the warning *)
+      let tp_abs = abs tp in
+      L.d_strln ("Checking tainted actual parameters from parameter number "^ (string_of_int tp_abs) ^ " onwards.");
+      let actual_params' = n_tail actual_params tp_abs in
+      L.d_str "Paramters to be checked:  [ ";
+      IList.iter(fun (e,_) ->
+          L.d_str (" " ^ (Sil.exp_to_string e) ^ " ");
+          match Prop.get_taint_attribute calling_prop e with
+          | Some (Sil.Ataint taint_info) -> report_taint_error e taint_info callee_pname caller_pname calling_prop
+          | _ -> ()) actual_params';
+      L.d_strln" ]"
+  | _ ->  ()
+
 (** Construct the actual precondition: add to the current state a copy
     of the (callee's) formal parameters instantiated with the actual
     parameters. *)
@@ -919,7 +957,7 @@ let inconsistent_actualpre_missing actual_pre split_opt =
 
 (* perform the taint analysis check by comparing the taint atoms in [calling_pi] with the untaint
    atoms required by the [missing_pi] computed during abduction *)
-let do_taint_check caller_pname callee_pname calling_prop missing_pi sub =
+let do_taint_check caller_pname callee_pname calling_prop missing_pi sub actual_params =
   let calling_pi = Prop.get_pi calling_prop in
   (* get a version of [missing_pi] whose var names match the names in calling pi *)
   let missing_pi_sub = Prop.pi_sub sub missing_pi in
@@ -948,17 +986,7 @@ let do_taint_check caller_pname callee_pname calling_prop missing_pi sub =
       let taint_info = match Prop.atom_get_exp_attribute taint_atom with
         | Some (_, Sil.Ataint taint_info) -> taint_info
         | _ -> failwith "Expected to get taint attr on atom" in
-      let err_desc =
+      report_taint_error e taint_info callee_pname caller_pname calling_prop in
-        Errdesc.explain_tainted_value_reaching_sensitive_function
-          calling_prop
-          e
-          taint_info
-          callee_pname
-          (State.get_loc ()) in
-      let exn =
-        Exceptions.Tainted_value_reaching_sensitive_function
-          (err_desc, __POS__) in
-      Reporting.log_warning caller_pname exn in
     IList.iter report_one_error taint_atoms in
   Sil.ExpMap.iter report_taint_errors taint_untaint_exp_map;
   (* filter out UNTAINT(e) atoms from [missing_pi] such that we have already reported a taint
@@ -974,6 +1002,7 @@ let do_taint_check caller_pname callee_pname calling_prop missing_pi sub =
               (fun a -> Sil.atom_equal atom a)
               untaint_atoms)
          taint_untaint_exp_map) in
+  check_taint_on_variadic_function callee_pname caller_pname actual_params calling_prop;
   IList.filter not_untaint_atom missing_pi_sub
 
 let class_cast_exn pname_opt texp1 texp2 exp ml_loc =
@@ -1026,7 +1055,7 @@ let exe_spec
       let do_split () =
         let missing_pi' =
           if Config.taint_analysis then
-            do_taint_check caller_pname callee_pname actual_pre missing_pi sub2
+            do_taint_check caller_pname callee_pname actual_pre missing_pi sub2 actual_params
           else missing_pi in
         process_splitting
           actual_pre sub1 sub2 frame missing_pi' missing_sigma

infer/src/backend/taint.ml

@@ -44,6 +44,17 @@ let sources = [
     taint_kind = Sil.Tk_shared_preferences_data;
     language = Config.Java
   };
+  (* === iOS === *)
+  {
+    classname = "NSHTTPCookie";
+    method_name = "value";
+    ret_type = "NSString *";
+    params = [];
+    is_static = false;
+    taint_kind = Sil.Tk_privacy_annotation;
+    language = Config.Clang
+  };
+
 ] @ FbTaint.sources
 
 (* list of (sensitive sinks, zero-indexed numbers of parameters that should not be tainted). note:
@@ -162,6 +173,53 @@ let sinks = [
     language = Config.Java;
   }, [0]);
 
+  (* === iOS === *)
+  ({
+    classname = "NSString";
+    method_name = "stringWithFormat:";
+    ret_type = "instancetype";
+    params = [];
+    is_static = true;
+    taint_kind = Sil.Tk_unknown;
+    language = Config.Clang;
+  }, [-2]);
+  ({
+    classname = "NSString";
+    method_name = "stringWithUTF8String:";
+    ret_type = "instancetype";
+    params = [];
+    is_static = true;
+    taint_kind = Sil.Tk_unknown;
+    language = Config.Clang
+  }, [-2]);
+  ({
+    classname = "NSString";
+    method_name = "localizedStringWithFormat:";
+    ret_type = "instancetype";
+    params = [];
+    is_static = true;
+    taint_kind = Sil.Tk_unknown;
+    language = Config.Clang
+  }, [-2]);
+  ({
+    classname = "NSString";
+    method_name = "initWithFormat:";
+    ret_type = "instancetype";
+    params = [];
+    is_static = false;
+    taint_kind = Sil.Tk_unknown;
+    language = Config.Clang
+  }, [-2]);
+  ({
+    classname = "NSString";
+    method_name = "stringWithString:";
+    ret_type = "instancetype";
+    params = [];
+    is_static = true;
+    taint_kind = Sil.Tk_unknown;
+    language = Config.Clang
+  }, [0]);
+
   (*  ==== iOS for testing only ==== *)
   ({
     classname = "ExampleViewController";

infer/tests/codetoanalyze/objc/errors/taint/sources.m

@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2016 - present Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+#import <Foundation/NSObject.h>
+#import <Foundation/NSString.h>
+#import <Foundation/NSHTTPCookie.h>
+
+void testNSHTTPCookie1() {
+
+  NSHTTPCookie* c = [NSHTTPCookie new];
+  NSString* s = c.value;
+
+  [NSString stringWithFormat:@"Test taint %@: ", s];
+}
+
+void testNSHTTPCookie2() {
+
+  NSHTTPCookie* c = [NSHTTPCookie new];
+  NSString* s = c.value;
+
+  [NSString localizedStringWithFormat:@"Test taint %@: ", s];
+}
+
+void testNSHTTPCookie3() {
+
+  NSHTTPCookie* c = [NSHTTPCookie new];
+  NSString* s = c.value;
+
+  [[NSString alloc] initWithFormat:@"Test taint %@", s];
+}
+
+void testNSHTTPCookie4() {
+
+  NSHTTPCookie* c = [NSHTTPCookie new];
+  NSString* s = c.value;
+
+  [NSString stringWithString:s];
+}

infer/tests/endtoend/objc/Taint2Test.java

@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 2013 - present Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+package endtoend.objc;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static utils.matchers.ResultContainsExactly.containsExactly;
+
+import com.google.common.collect.ImmutableList;
+
+import org.junit.BeforeClass;
+import org.junit.ClassRule;
+import org.junit.Test;
+
+import java.io.IOException;
+
+import utils.DebuggableTemporaryFolder;
+import utils.InferException;
+import utils.InferResults;
+import utils.InferRunner;
+
+public class Taint2Test {
+
+  public static final String TaintFile =
+      "infer/tests/codetoanalyze/objc/errors/taint/sources.m";
+
+  public static final String TAINTED_VALUE = "TAINTED_VALUE_REACHING_SENSITIVE_FUNCTION";
+
+  private static ImmutableList<String> inferCmd;
+
+  @ClassRule
+  public static DebuggableTemporaryFolder folder = new DebuggableTemporaryFolder();
+
+
+  @BeforeClass
+  public static void runInfer() throws InterruptedException, IOException {
+    inferCmd = InferRunner.createObjCInferCommandWithMLBuckets(
+        folder,
+        TaintFile,
+        "cf",
+        false);
+  }
+
+  @Test
+  public void whenInferRunsOnTaintFileErrorFound()
+      throws InterruptedException, IOException, InferException {
+    InferResults inferResults = InferRunner.runInferObjC(inferCmd);
+    String[] methods = {
+        "testNSHTTPCookie1",
+        "testNSHTTPCookie2",
+        "testNSHTTPCookie3",
+        "testNSHTTPCookie4"
+    };
+
+    assertThat(
+        "Results should contain tainted value reaching sensitive function.",
+        inferResults,
+        containsExactly(
+            TAINTED_VALUE,
+            TaintFile,
+            methods
+        )
+    );
+  }
+
+}