[ILVerify] Fix assembly friend access being sensitive to white-spaces (#4950)

* Changed friend assembly parsing to use AssemblyName class instead.

3 files changed, 34 insertions, 29 deletions

diff --git a/src/ILVerify/src/AccessVerificationHelpers.cs b/src/ILVerify/src/AccessVerificationHelpers.cs
index 9274cad54..b0f31bd2a 100644
--- a/src/ILVerify/src/AccessVerificationHelpers.cs
+++ b/src/ILVerify/src/AccessVerificationHelpers.cs
@@ -2,7 +2,6 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System;
 using System.Diagnostics;
 using System.Reflection;
 using Internal.TypeSystem;
@@ -250,50 +249,38 @@ namespace ILVerify
             return false;
         }
 
-        private const string PUBLIC_KEY = "PublicKey=";
-
         private static bool GrantsFriendAccessTo(this ModuleDesc module, ModuleDesc friendModule)
         {
             var assembly = (EcmaAssembly)module;
-            var friendAssembly = (IAssemblyDesc)friendModule;
-
-            var friendName = friendAssembly.GetName();
-            var friendPublicKey = friendName.GetPublicKey();
+            var friendName = ((IAssemblyDesc)friendModule).GetName();
 
             foreach (var attribute in assembly.GetDecodedCustomAttributes("System.Runtime.CompilerServices", "InternalsVisibleToAttribute"))
             {
-                var friendValues = ((string)attribute.FixedArguments[0].Value).Split(new string[] { ", " }, StringSplitOptions.None);
-                if (friendValues.Length >= 1 && friendValues.Length <= 2)
-                {
-                    if (friendValues[0] != friendName.Name)
-                        continue;
-
-                    if (friendValues.Length == 2 &&
-                        (!friendValues[1].StartsWith(PUBLIC_KEY) || !IsSamePublicKey(friendPublicKey, friendValues[1].Substring(PUBLIC_KEY.Length))))
-                        continue;
+                AssemblyName friendAttributeName = new AssemblyName((string)attribute.FixedArguments[0].Value);
+                if (friendName.Name != friendAttributeName.Name)
+                    continue;
 
+                // Comparing PublicKeyToken, since GetPublicKey returns null due to a bug
+                if (IsSamePublicKey(friendAttributeName.GetPublicKeyToken(), friendName.GetPublicKeyToken()))
                     return true;
-                }
             }
             return false;
         }
 
-        private static bool IsSamePublicKey(byte[] key1, string key2)
+        private static bool IsSamePublicKey(byte[] key1, byte[] key2)
         {
-            if (key1.Length * 2 != key2.Length)
+            if (key1 == null)
+                return key2 == null || key2.Length == 0;
+            if (key2 == null)
+                return key1 == null || key1.Length == 0;
+
+            if (key1.Length != key2.Length)
                 return false;
 
-            for (int i = 0; i < key1.Length; i++)
+            for (int i = 0; i < key1.Length; ++i)
             {
-                try
-                {
-                    if (key1[i] != Convert.ToByte(key2[i * 2] + "" + key2[i * 2 + 1], 16))
-                        return false;
-                }
-                catch
-                {
+                if (key1[i] != key2[i])
                     return false;
-                }
             }
 
             return true;
diff --git a/src/ILVerify/tests/ILTests/AccessTestsExtern.il b/src/ILVerify/tests/ILTests/AccessTestsExtern.il
index 31be7b663..39939e1bf 100644
--- a/src/ILVerify/tests/ILTests/AccessTestsExtern.il
+++ b/src/ILVerify/tests/ILTests/AccessTestsExtern.il
@@ -10,7 +10,11 @@
 {
 }
 
-.assembly AccessTestsExternal
+.assembly extern AccessTestsFriend
+{
+}
+
+.assembly AccessTestsExtern
 {
 }
 
@@ -102,6 +106,13 @@
         call      void [AccessTests]SimpleClass::FamilyAndAssemblyMethod()
         ret
     }
+
+    .method private hidebysig instance void Load.AssemFieldOfFriendAssemblyWithSpace_Valid() cil managed
+    {
+        ldsfld       int32 [AccessTestsFriend]AccessTestsFriendType::assemblyField
+        pop
+        ret
+    }
 }
 
 .class public auto ansi beforefieldinit DerivedType
diff --git a/src/ILVerify/tests/ILTests/AccessTestsFriend.il b/src/ILVerify/tests/ILTests/AccessTestsFriend.il
index 869470b62..78db6d8ad 100644
--- a/src/ILVerify/tests/ILTests/AccessTestsFriend.il
+++ b/src/ILVerify/tests/ILTests/AccessTestsFriend.il
@@ -16,6 +16,13 @@
     .custom instance void [System.Runtime]System.Runtime.CompilerServices.InternalsVisibleToAttribute::.ctor(string) = (
         01 00 0b 41 63 63 65 73 73 54 65 73 74 73 00 00
     )
+
+    // InternalsVisibleTo("AccessTestsExtern ")
+    //                                      ^ purposeful space at the end
+    .custom instance void [System.Runtime]System.Runtime.CompilerServices.InternalsVisibleToAttribute::.ctor(string) = (
+        01 00 12 41 63 63 65 73 73 54 65 73 74 73 45 78
+        74 65 72 6e 20 00 00
+    )
 }
 
 .class private auto ansi beforefieldinit AccessTestsFriendType