Review of culture-independent String comparison methods

3 files changed, 34 insertions, 14 deletions

diff --git a/crypto/src/util/Platform.cs b/crypto/src/util/Platform.cs
index d4b18f182..361fe7536 100644
--- a/crypto/src/util/Platform.cs
+++ b/crypto/src/util/Platform.cs
@@ -13,6 +13,8 @@ namespace Org.BouncyCastle.Utilities
 {
     internal abstract class Platform
     {
+        private static readonly CompareInfo InvariantCompareInfo = CultureInfo.InvariantCulture.CompareInfo;
+
 #if NETCF_1_0 || NETCF_2_0
         private static string GetNewLine()
         {
@@ -30,16 +32,12 @@ namespace Org.BouncyCastle.Utilities
         }
 #endif
 
-        internal static int CompareIgnoreCase(string a, string b)
+        internal static bool EqualsIgnoreCase(string a, string b)
         {
-#if SILVERLIGHT
-            return String.Compare(a, b, StringComparison.InvariantCultureIgnoreCase);
-#elif SYS_RUNTIME
-            return String.Compare(a, b, StringComparison.OrdinalIgnoreCase);
-#elif PORTABLE
-            return String.Compare(a, b, CultureInfo.InvariantCulture, CompareOptions.IgnoreCase);
+#if PORTABLE
+            return String.Equals(a, b, StringComparison.OrdinalIgnoreCase);
 #else
-            return String.Compare(a, b, true);
+            return ToUpperInvariant(a) == ToUpperInvariant(b);
 #endif
         }
 
@@ -202,5 +200,25 @@ namespace Org.BouncyCastle.Utilities
             t.Close();
         }
 #endif
+
+        internal static int IndexOf(string source, string value)
+        {
+            return InvariantCompareInfo.IndexOf(source, value, CompareOptions.Ordinal);
+        }
+
+        internal static int LastIndexOf(string source, string value)
+        {
+            return InvariantCompareInfo.LastIndexOf(source, value, CompareOptions.Ordinal);
+        }
+
+        internal static bool StartsWith(string source, string prefix)
+        {
+            return InvariantCompareInfo.IsPrefix(source, prefix, CompareOptions.Ordinal);
+        }
+
+        internal static bool EndsWith(string source, string suffix)
+        {
+            return InvariantCompareInfo.IsSuffix(source, suffix, CompareOptions.Ordinal);
+        }
     }
 }
diff --git a/crypto/src/util/io/pem/PemReader.cs b/crypto/src/util/io/pem/PemReader.cs
index b3284705d..bf712b6de 100644
--- a/crypto/src/util/io/pem/PemReader.cs
+++ b/crypto/src/util/io/pem/PemReader.cs
@@ -35,7 +35,7 @@ namespace Org.BouncyCastle.Utilities.IO.Pem
 		{
 			string line = reader.ReadLine();
 
-			if (line != null && line.StartsWith(BeginString))
+            if (line != null && Platform.StartsWith(line, BeginString))
 			{
 				line = line.Substring(BeginString.Length);
 				int index = line.IndexOf('-');
@@ -56,7 +56,7 @@ namespace Org.BouncyCastle.Utilities.IO.Pem
 
 			string line;
 			while ((line = reader.ReadLine()) != null
-				&& line.IndexOf(endMarker) == -1)
+                && Platform.IndexOf(line, endMarker) == -1)
 			{
 				int colonPos = line.IndexOf(':');
 
@@ -69,8 +69,10 @@ namespace Org.BouncyCastle.Utilities.IO.Pem
 					// Process field
 					string fieldName = line.Substring(0, colonPos).Trim();
 
-					if (fieldName.StartsWith("X-"))
-						fieldName = fieldName.Substring(2);
+                    if (Platform.StartsWith(fieldName, "X-"))
+                    {
+                        fieldName = fieldName.Substring(2);
+                    }
 
 					string fieldValue = line.Substring(colonPos + 1).Trim();
 
diff --git a/crypto/src/util/net/IPAddress.cs b/crypto/src/util/net/IPAddress.cs
index 2a30a15f0..38c124590 100644
--- a/crypto/src/util/net/IPAddress.cs
+++ b/crypto/src/util/net/IPAddress.cs
@@ -85,7 +85,7 @@ namespace Org.BouncyCastle.Utilities.Net
 		public static bool IsValidIPv4WithNetmask(
 			string address)
 		{
-			int index = address.IndexOf("/");
+			int index = address.IndexOf('/');
 			string mask = address.Substring(index + 1);
 
 			return (index > 0) && IsValidIPv4(address.Substring(0, index))
@@ -95,7 +95,7 @@ namespace Org.BouncyCastle.Utilities.Net
 		public static bool IsValidIPv6WithNetmask(
 			string address)
 		{
-			int index = address.IndexOf("/");
+			int index = address.IndexOf('/');
 			string mask = address.Substring(index + 1);
 
 			return (index > 0) && (IsValidIPv6(address.Substring(0, index))