1 files changed, 88 insertions, 16 deletions

diff --git a/crypto/src/asn1/Asn1Utilities.cs b/crypto/src/asn1/Asn1Utilities.cs
index fe6db2df7..7b014ef00 100644
--- a/crypto/src/asn1/Asn1Utilities.cs
+++ b/crypto/src/asn1/Asn1Utilities.cs
@@ -4,6 +4,23 @@ namespace Org.BouncyCastle.Asn1
 {
     public abstract class Asn1Utilities
     {
+        internal static Asn1TaggedObject CheckTag(Asn1TaggedObject taggedObject, int tagClass, int tagNo)
+        {
+            if (!taggedObject.HasTag(tagClass, tagNo))
+            {
+                string expected = GetTagText(tagClass, tagNo);
+                string found = GetTagText(taggedObject);
+                throw new InvalidOperationException("Expected " + expected + " tag but found " + found);
+            }
+            return taggedObject;
+        }
+
+
+        internal static string GetTagText(Asn1Tag tag)
+        {
+            return GetTagText(tag.TagClass, tag.TagNo);
+        }
+
         public static string GetTagText(Asn1TaggedObject taggedObject)
         {
             return GetTagText(taggedObject.TagClass, taggedObject.TagNo);
@@ -24,20 +41,14 @@ namespace Org.BouncyCastle.Asn1
             }
         }
 
+
         /*
          * Wrappers for Asn1TaggedObject.GetExplicitBaseObject
          */
 
         public static Asn1Encodable GetExplicitBaseObject(Asn1TaggedObject taggedObject, int tagClass, int tagNo)
         {
-            if (!taggedObject.HasTag(tagClass, tagNo))
-            {
-                string expected = GetTagText(tagClass, tagNo);
-                string found = GetTagText(taggedObject);
-                throw new InvalidOperationException("Expected " + expected + " tag but found " + found);
-            }
-
-            return taggedObject.GetExplicitBaseObject();
+            return CheckTag(taggedObject, tagClass, tagNo).GetExplicitBaseObject();
         }
 
         public static Asn1Encodable GetExplicitContextBaseObject(Asn1TaggedObject taggedObject, int tagNo)
@@ -65,14 +76,7 @@ namespace Org.BouncyCastle.Asn1
 
         public static Asn1TaggedObject GetExplicitBaseTagged(Asn1TaggedObject taggedObject, int tagClass, int tagNo)
         {
-            if (!taggedObject.HasTag(tagClass, tagNo))
-            {
-                string expected = GetTagText(tagClass, tagNo);
-                string found = GetTagText(taggedObject);
-                throw new InvalidOperationException("Expected " + expected + " tag but found " + found);
-            }
-
-            return taggedObject.GetExplicitBaseTagged();
+            return CheckTag(taggedObject, tagClass, tagNo).GetExplicitBaseTagged();
         }
 
         public static Asn1TaggedObject GetExplicitContextBaseTagged(Asn1TaggedObject taggedObject, int tagNo)
@@ -92,5 +96,73 @@ namespace Org.BouncyCastle.Asn1
         {
             return TryGetExplicitBaseTagged(taggedObject, Asn1Tags.ContextSpecific, tagNo);
         }
+
+
+        /*
+         * Wrappers for Asn1TaggedObject.GetImplicitBaseTagged
+         */
+
+        public static Asn1TaggedObject GetImplicitBaseTagged(Asn1TaggedObject taggedObject, int tagClass, int tagNo,
+            int baseTagClass, int baseTagNo)
+        {
+            return CheckTag(taggedObject, tagClass, tagNo).GetImplicitBaseTagged(baseTagClass, baseTagNo);
+        }
+
+        public static Asn1TaggedObject GetImplicitContextBaseTagged(Asn1TaggedObject taggedObject, int tagNo,
+            int baseTagClass, int baseTagNo)
+        {
+            return GetImplicitBaseTagged(taggedObject, Asn1Tags.ContextSpecific, tagNo, baseTagClass, baseTagNo);
+        }
+
+        public static Asn1TaggedObject TryGetImplicitBaseTagged(Asn1TaggedObject taggedObject, int tagClass, int tagNo,
+            int baseTagClass, int baseTagNo)
+        {
+            if (!taggedObject.HasTag(tagClass, tagNo))
+            {
+                return null;
+            }
+
+            return taggedObject.GetImplicitBaseTagged(baseTagClass, baseTagNo);
+        }
+
+        public static Asn1TaggedObject TryGetImplicitContextBaseTagged(Asn1TaggedObject taggedObject, int tagNo,
+            int baseTagClass, int baseTagNo)
+        {
+            return TryGetImplicitBaseTagged(taggedObject, Asn1Tags.ContextSpecific, tagNo, baseTagClass, baseTagNo);
+        }
+
+
+        /*
+         * Wrappers for Asn1TaggedObject.GetBaseUniversal
+         */
+
+        public static Asn1Object GetBaseUniversal(Asn1TaggedObject taggedObject, int tagClass, int tagNo,
+            bool declaredExplicit, int baseTagNo)
+        {
+            return CheckTag(taggedObject, tagClass, tagNo).GetBaseUniversal(declaredExplicit, baseTagNo);
+        }
+
+        public static Asn1Object GetContextBaseUniversal(Asn1TaggedObject taggedObject, int tagNo,
+            bool declaredExplicit, int baseTagNo)
+        {
+            return GetBaseUniversal(taggedObject, Asn1Tags.ContextSpecific, tagNo, declaredExplicit, baseTagNo);
+        }
+
+        public static Asn1Object TryGetBaseUniversal(Asn1TaggedObject taggedObject, int tagClass, int tagNo,
+            bool declaredExplicit, int baseTagNo)
+        {
+            if (!taggedObject.HasTag(tagClass, tagNo))
+            {
+                return null;
+            }
+
+            return taggedObject.GetBaseUniversal(declaredExplicit, baseTagNo);
+        }
+
+        public static Asn1Object TryGetContextBaseUniversal(Asn1TaggedObject taggedObject, int tagNo,
+            bool declaredExplicit, int baseTagNo)
+        {
+            return TryGetBaseUniversal(taggedObject, Asn1Tags.ContextSpecific, tagNo, declaredExplicit, baseTagNo);
+        }
     }
 }