1 files changed, 5 insertions, 3 deletions
diff --git a/crypto/src/security/MacUtilities.cs b/crypto/src/security/MacUtilities.cs
index d7fe91142..fab9b1d41 100644
--- a/crypto/src/security/MacUtilities.cs
+++ b/crypto/src/security/MacUtilities.cs
@@ -1,4 +1,6 @@
+using System;
 using System.Collections;
+using System.Globalization;
 
 using Org.BouncyCastle.Asn1;
 using Org.BouncyCastle.Asn1.Iana;
@@ -112,15 +114,15 @@ namespace Org.BouncyCastle.Security
                 mechanism = upper;
             }
 
-            if (mechanism.StartsWith("PBEWITH"))
+            if (Platform.StartsWith(mechanism, "PBEWITH"))
             {
                 mechanism = mechanism.Substring("PBEWITH".Length);
             }
 
-            if (mechanism.StartsWith("HMAC"))
+            if (Platform.StartsWith(mechanism, "HMAC"))
             {
                 string digestName;
-                if (mechanism.StartsWith("HMAC-") || mechanism.StartsWith("HMAC/"))
+                if (Platform.StartsWith(mechanism, "HMAC-") || Platform.StartsWith(mechanism, "HMAC/"))
                 {
                     digestName = mechanism.Substring(5);
                 }