Generics migration complete

1 files changed, 396 insertions, 442 deletions

diff --git a/crypto/src/security/CipherUtilities.cs b/crypto/src/security/CipherUtilities.cs
index 3b92add00..a6849c102 100644
--- a/crypto/src/security/CipherUtilities.cs
+++ b/crypto/src/security/CipherUtilities.cs
@@ -1,5 +1,5 @@
 using System;
-using System.Collections;
+using System.Collections.Generic;
 
 using Org.BouncyCastle.Asn1;
 using Org.BouncyCastle.Asn1.CryptoPro;
@@ -19,13 +19,14 @@ using Org.BouncyCastle.Crypto.Macs;
 using Org.BouncyCastle.Crypto.Modes;
 using Org.BouncyCastle.Crypto.Paddings;
 using Org.BouncyCastle.Utilities;
+using Org.BouncyCastle.Utilities.Collections;
 
 namespace Org.BouncyCastle.Security
 {
     /// <remarks>
     ///  Cipher Utility class contains methods that can not be specifically grouped into other classes.
     /// </remarks>
-    public sealed class CipherUtilities
+    public static class CipherUtilities
     {
         private enum CipherAlgorithm {
             AES,
@@ -111,8 +112,8 @@ namespace Org.BouncyCastle.Security
             ZEROBYTEPADDING,
         };
 
-        private static readonly IDictionary algorithms = Platform.CreateHashtable();
-        private static readonly IDictionary oids = Platform.CreateHashtable();
+        private static readonly Dictionary<string, string> Algorithms =
+            new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
 
         static CipherUtilities()
         {
@@ -123,172 +124,142 @@ namespace Org.BouncyCastle.Security
 
             // TODO Flesh out the list of aliases
 
-            algorithms[NistObjectIdentifiers.IdAes128Cbc.Id] = "AES/CBC/PKCS7PADDING";
-            algorithms[NistObjectIdentifiers.IdAes192Cbc.Id] = "AES/CBC/PKCS7PADDING";
-            algorithms[NistObjectIdentifiers.IdAes256Cbc.Id] = "AES/CBC/PKCS7PADDING";
-
-            algorithms[NistObjectIdentifiers.IdAes128Ccm.Id] = "AES/CCM/NOPADDING";
-            algorithms[NistObjectIdentifiers.IdAes192Ccm.Id] = "AES/CCM/NOPADDING";
-            algorithms[NistObjectIdentifiers.IdAes256Ccm.Id] = "AES/CCM/NOPADDING";
-
-            algorithms[NistObjectIdentifiers.IdAes128Cfb.Id] = "AES/CFB/NOPADDING";
-            algorithms[NistObjectIdentifiers.IdAes192Cfb.Id] = "AES/CFB/NOPADDING";
-            algorithms[NistObjectIdentifiers.IdAes256Cfb.Id] = "AES/CFB/NOPADDING";
-
-            algorithms[NistObjectIdentifiers.IdAes128Ecb.Id] = "AES/ECB/PKCS7PADDING";
-            algorithms[NistObjectIdentifiers.IdAes192Ecb.Id] = "AES/ECB/PKCS7PADDING";
-            algorithms[NistObjectIdentifiers.IdAes256Ecb.Id] = "AES/ECB/PKCS7PADDING";
-            algorithms["AES//PKCS7"] = "AES/ECB/PKCS7PADDING";
-            algorithms["AES//PKCS7PADDING"] = "AES/ECB/PKCS7PADDING";
-            algorithms["AES//PKCS5"] = "AES/ECB/PKCS7PADDING";
-            algorithms["AES//PKCS5PADDING"] = "AES/ECB/PKCS7PADDING";
+            Algorithms[NistObjectIdentifiers.IdAes128Cbc.Id] = "AES/CBC/PKCS7PADDING";
+            Algorithms[NistObjectIdentifiers.IdAes192Cbc.Id] = "AES/CBC/PKCS7PADDING";
+            Algorithms[NistObjectIdentifiers.IdAes256Cbc.Id] = "AES/CBC/PKCS7PADDING";
+
+            Algorithms[NistObjectIdentifiers.IdAes128Ccm.Id] = "AES/CCM/NOPADDING";
+            Algorithms[NistObjectIdentifiers.IdAes192Ccm.Id] = "AES/CCM/NOPADDING";
+            Algorithms[NistObjectIdentifiers.IdAes256Ccm.Id] = "AES/CCM/NOPADDING";
+
+            Algorithms[NistObjectIdentifiers.IdAes128Cfb.Id] = "AES/CFB/NOPADDING";
+            Algorithms[NistObjectIdentifiers.IdAes192Cfb.Id] = "AES/CFB/NOPADDING";
+            Algorithms[NistObjectIdentifiers.IdAes256Cfb.Id] = "AES/CFB/NOPADDING";
+
+            Algorithms[NistObjectIdentifiers.IdAes128Ecb.Id] = "AES/ECB/PKCS7PADDING";
+            Algorithms[NistObjectIdentifiers.IdAes192Ecb.Id] = "AES/ECB/PKCS7PADDING";
+            Algorithms[NistObjectIdentifiers.IdAes256Ecb.Id] = "AES/ECB/PKCS7PADDING";
+            Algorithms["AES//PKCS7"] = "AES/ECB/PKCS7PADDING";
+            Algorithms["AES//PKCS7PADDING"] = "AES/ECB/PKCS7PADDING";
+            Algorithms["AES//PKCS5"] = "AES/ECB/PKCS7PADDING";
+            Algorithms["AES//PKCS5PADDING"] = "AES/ECB/PKCS7PADDING";
 
-            algorithms[NistObjectIdentifiers.IdAes128Gcm.Id] = "AES/GCM/NOPADDING";
-            algorithms[NistObjectIdentifiers.IdAes192Gcm.Id] = "AES/GCM/NOPADDING";
-            algorithms[NistObjectIdentifiers.IdAes256Gcm.Id] = "AES/GCM/NOPADDING";
+            Algorithms[NistObjectIdentifiers.IdAes128Gcm.Id] = "AES/GCM/NOPADDING";
+            Algorithms[NistObjectIdentifiers.IdAes192Gcm.Id] = "AES/GCM/NOPADDING";
+            Algorithms[NistObjectIdentifiers.IdAes256Gcm.Id] = "AES/GCM/NOPADDING";
 
-            algorithms[NistObjectIdentifiers.IdAes128Ofb.Id] = "AES/OFB/NOPADDING";
-            algorithms[NistObjectIdentifiers.IdAes192Ofb.Id] = "AES/OFB/NOPADDING";
-            algorithms[NistObjectIdentifiers.IdAes256Ofb.Id] = "AES/OFB/NOPADDING";
+            Algorithms[NistObjectIdentifiers.IdAes128Ofb.Id] = "AES/OFB/NOPADDING";
+            Algorithms[NistObjectIdentifiers.IdAes192Ofb.Id] = "AES/OFB/NOPADDING";
+            Algorithms[NistObjectIdentifiers.IdAes256Ofb.Id] = "AES/OFB/NOPADDING";
 
-            algorithms[NsriObjectIdentifiers.id_aria128_cbc.Id] = "ARIA/CBC/PKCS7PADDING";
-            algorithms[NsriObjectIdentifiers.id_aria192_cbc.Id] = "ARIA/CBC/PKCS7PADDING";
-            algorithms[NsriObjectIdentifiers.id_aria256_cbc.Id] = "ARIA/CBC/PKCS7PADDING";
+            Algorithms[NsriObjectIdentifiers.id_aria128_cbc.Id] = "ARIA/CBC/PKCS7PADDING";
+            Algorithms[NsriObjectIdentifiers.id_aria192_cbc.Id] = "ARIA/CBC/PKCS7PADDING";
+            Algorithms[NsriObjectIdentifiers.id_aria256_cbc.Id] = "ARIA/CBC/PKCS7PADDING";
 
-            algorithms[NsriObjectIdentifiers.id_aria128_ccm.Id] = "ARIA/CCM/NOPADDING";
-            algorithms[NsriObjectIdentifiers.id_aria192_ccm.Id] = "ARIA/CCM/NOPADDING";
-            algorithms[NsriObjectIdentifiers.id_aria256_ccm.Id] = "ARIA/CCM/NOPADDING";
+            Algorithms[NsriObjectIdentifiers.id_aria128_ccm.Id] = "ARIA/CCM/NOPADDING";
+            Algorithms[NsriObjectIdentifiers.id_aria192_ccm.Id] = "ARIA/CCM/NOPADDING";
+            Algorithms[NsriObjectIdentifiers.id_aria256_ccm.Id] = "ARIA/CCM/NOPADDING";
 
-            algorithms[NsriObjectIdentifiers.id_aria128_cfb.Id] = "ARIA/CFB/NOPADDING";
-            algorithms[NsriObjectIdentifiers.id_aria192_cfb.Id] = "ARIA/CFB/NOPADDING";
-            algorithms[NsriObjectIdentifiers.id_aria256_cfb.Id] = "ARIA/CFB/NOPADDING";
+            Algorithms[NsriObjectIdentifiers.id_aria128_cfb.Id] = "ARIA/CFB/NOPADDING";
+            Algorithms[NsriObjectIdentifiers.id_aria192_cfb.Id] = "ARIA/CFB/NOPADDING";
+            Algorithms[NsriObjectIdentifiers.id_aria256_cfb.Id] = "ARIA/CFB/NOPADDING";
 
-            algorithms[NsriObjectIdentifiers.id_aria128_ctr.Id] = "ARIA/CTR/NOPADDING";
-            algorithms[NsriObjectIdentifiers.id_aria192_ctr.Id] = "ARIA/CTR/NOPADDING";
-            algorithms[NsriObjectIdentifiers.id_aria256_ctr.Id] = "ARIA/CTR/NOPADDING";
+            Algorithms[NsriObjectIdentifiers.id_aria128_ctr.Id] = "ARIA/CTR/NOPADDING";
+            Algorithms[NsriObjectIdentifiers.id_aria192_ctr.Id] = "ARIA/CTR/NOPADDING";
+            Algorithms[NsriObjectIdentifiers.id_aria256_ctr.Id] = "ARIA/CTR/NOPADDING";
 
-            algorithms[NsriObjectIdentifiers.id_aria128_ecb.Id] = "ARIA/ECB/PKCS7PADDING";
-            algorithms[NsriObjectIdentifiers.id_aria192_ecb.Id] = "ARIA/ECB/PKCS7PADDING";
-            algorithms[NsriObjectIdentifiers.id_aria256_ecb.Id] = "ARIA/ECB/PKCS7PADDING";
-            algorithms["ARIA//PKCS7"] = "ARIA/ECB/PKCS7PADDING";
-            algorithms["ARIA//PKCS7PADDING"] = "ARIA/ECB/PKCS7PADDING";
-            algorithms["ARIA//PKCS5"] = "ARIA/ECB/PKCS7PADDING";
-            algorithms["ARIA//PKCS5PADDING"] = "ARIA/ECB/PKCS7PADDING";
+            Algorithms[NsriObjectIdentifiers.id_aria128_ecb.Id] = "ARIA/ECB/PKCS7PADDING";
+            Algorithms[NsriObjectIdentifiers.id_aria192_ecb.Id] = "ARIA/ECB/PKCS7PADDING";
+            Algorithms[NsriObjectIdentifiers.id_aria256_ecb.Id] = "ARIA/ECB/PKCS7PADDING";
+            Algorithms["ARIA//PKCS7"] = "ARIA/ECB/PKCS7PADDING";
+            Algorithms["ARIA//PKCS7PADDING"] = "ARIA/ECB/PKCS7PADDING";
+            Algorithms["ARIA//PKCS5"] = "ARIA/ECB/PKCS7PADDING";
+            Algorithms["ARIA//PKCS5PADDING"] = "ARIA/ECB/PKCS7PADDING";
 
-            algorithms[NsriObjectIdentifiers.id_aria128_gcm.Id] = "ARIA/GCM/NOPADDING";
-            algorithms[NsriObjectIdentifiers.id_aria192_gcm.Id] = "ARIA/GCM/NOPADDING";
-            algorithms[NsriObjectIdentifiers.id_aria256_gcm.Id] = "ARIA/GCM/NOPADDING";
+            Algorithms[NsriObjectIdentifiers.id_aria128_gcm.Id] = "ARIA/GCM/NOPADDING";
+            Algorithms[NsriObjectIdentifiers.id_aria192_gcm.Id] = "ARIA/GCM/NOPADDING";
+            Algorithms[NsriObjectIdentifiers.id_aria256_gcm.Id] = "ARIA/GCM/NOPADDING";
 
-            algorithms[NsriObjectIdentifiers.id_aria128_ofb.Id] = "ARIA/OFB/NOPADDING";
-            algorithms[NsriObjectIdentifiers.id_aria192_ofb.Id] = "ARIA/OFB/NOPADDING";
-            algorithms[NsriObjectIdentifiers.id_aria256_ofb.Id] = "ARIA/OFB/NOPADDING";
+            Algorithms[NsriObjectIdentifiers.id_aria128_ofb.Id] = "ARIA/OFB/NOPADDING";
+            Algorithms[NsriObjectIdentifiers.id_aria192_ofb.Id] = "ARIA/OFB/NOPADDING";
+            Algorithms[NsriObjectIdentifiers.id_aria256_ofb.Id] = "ARIA/OFB/NOPADDING";
 
-            algorithms["RSA/ECB/PKCS1"] = "RSA//PKCS1PADDING";
-            algorithms["RSA/ECB/PKCS1PADDING"] = "RSA//PKCS1PADDING";
-            algorithms[PkcsObjectIdentifiers.RsaEncryption.Id] = "RSA//PKCS1PADDING";
-            algorithms[PkcsObjectIdentifiers.IdRsaesOaep.Id] = "RSA//OAEPPADDING";
+            Algorithms["RSA/ECB/PKCS1"] = "RSA//PKCS1PADDING";
+            Algorithms["RSA/ECB/PKCS1PADDING"] = "RSA//PKCS1PADDING";
+            Algorithms[PkcsObjectIdentifiers.RsaEncryption.Id] = "RSA//PKCS1PADDING";
+            Algorithms[PkcsObjectIdentifiers.IdRsaesOaep.Id] = "RSA//OAEPPADDING";
 
-            algorithms[OiwObjectIdentifiers.DesCbc.Id] = "DES/CBC";
-            algorithms[OiwObjectIdentifiers.DesCfb.Id] = "DES/CFB";
-            algorithms[OiwObjectIdentifiers.DesEcb.Id] = "DES/ECB";
-            algorithms[OiwObjectIdentifiers.DesOfb.Id] = "DES/OFB";
-            algorithms[OiwObjectIdentifiers.DesEde.Id] = "DESEDE";
-            algorithms["TDEA"] = "DESEDE";
-            algorithms[PkcsObjectIdentifiers.DesEde3Cbc.Id] = "DESEDE/CBC";
-            algorithms[PkcsObjectIdentifiers.RC2Cbc.Id] = "RC2/CBC";
-            algorithms["1.3.6.1.4.1.188.7.1.1.2"] = "IDEA/CBC";
-            algorithms["1.2.840.113533.7.66.10"] = "CAST5/CBC";
+            Algorithms[OiwObjectIdentifiers.DesCbc.Id] = "DES/CBC";
+            Algorithms[OiwObjectIdentifiers.DesCfb.Id] = "DES/CFB";
+            Algorithms[OiwObjectIdentifiers.DesEcb.Id] = "DES/ECB";
+            Algorithms[OiwObjectIdentifiers.DesOfb.Id] = "DES/OFB";
+            Algorithms[OiwObjectIdentifiers.DesEde.Id] = "DESEDE";
+            Algorithms["TDEA"] = "DESEDE";
+            Algorithms[PkcsObjectIdentifiers.DesEde3Cbc.Id] = "DESEDE/CBC";
+            Algorithms[PkcsObjectIdentifiers.RC2Cbc.Id] = "RC2/CBC";
+            Algorithms["1.3.6.1.4.1.188.7.1.1.2"] = "IDEA/CBC";
+            Algorithms["1.2.840.113533.7.66.10"] = "CAST5/CBC";
 
-            algorithms["RC4"] = "ARC4";
-            algorithms["ARCFOUR"] = "ARC4";
-            algorithms["1.2.840.113549.3.4"] = "ARC4";
+            Algorithms["RC4"] = "ARC4";
+            Algorithms["ARCFOUR"] = "ARC4";
+            Algorithms["1.2.840.113549.3.4"] = "ARC4";
 
 
 
-            algorithms["PBEWITHSHA1AND128BITRC4"] = "PBEWITHSHAAND128BITRC4";
-            algorithms[PkcsObjectIdentifiers.PbeWithShaAnd128BitRC4.Id] = "PBEWITHSHAAND128BITRC4";
-            algorithms["PBEWITHSHA1AND40BITRC4"] = "PBEWITHSHAAND40BITRC4";
-            algorithms[PkcsObjectIdentifiers.PbeWithShaAnd40BitRC4.Id] = "PBEWITHSHAAND40BITRC4";
+            Algorithms["PBEWITHSHA1AND128BITRC4"] = "PBEWITHSHAAND128BITRC4";
+            Algorithms[PkcsObjectIdentifiers.PbeWithShaAnd128BitRC4.Id] = "PBEWITHSHAAND128BITRC4";
+            Algorithms["PBEWITHSHA1AND40BITRC4"] = "PBEWITHSHAAND40BITRC4";
+            Algorithms[PkcsObjectIdentifiers.PbeWithShaAnd40BitRC4.Id] = "PBEWITHSHAAND40BITRC4";
 
-            algorithms["PBEWITHSHA1ANDDES"] = "PBEWITHSHA1ANDDES-CBC";
-            algorithms[PkcsObjectIdentifiers.PbeWithSha1AndDesCbc.Id] = "PBEWITHSHA1ANDDES-CBC";
-            algorithms["PBEWITHSHA1ANDRC2"] = "PBEWITHSHA1ANDRC2-CBC";
-            algorithms[PkcsObjectIdentifiers.PbeWithSha1AndRC2Cbc.Id] = "PBEWITHSHA1ANDRC2-CBC";
+            Algorithms["PBEWITHSHA1ANDDES"] = "PBEWITHSHA1ANDDES-CBC";
+            Algorithms[PkcsObjectIdentifiers.PbeWithSha1AndDesCbc.Id] = "PBEWITHSHA1ANDDES-CBC";
+            Algorithms["PBEWITHSHA1ANDRC2"] = "PBEWITHSHA1ANDRC2-CBC";
+            Algorithms[PkcsObjectIdentifiers.PbeWithSha1AndRC2Cbc.Id] = "PBEWITHSHA1ANDRC2-CBC";
 
-            algorithms["PBEWITHSHA1AND3-KEYTRIPLEDES-CBC"] = "PBEWITHSHAAND3-KEYTRIPLEDES-CBC";
-            algorithms["PBEWITHSHAAND3KEYTRIPLEDES"] = "PBEWITHSHAAND3-KEYTRIPLEDES-CBC";
-            algorithms[PkcsObjectIdentifiers.PbeWithShaAnd3KeyTripleDesCbc.Id] = "PBEWITHSHAAND3-KEYTRIPLEDES-CBC";
-            algorithms["PBEWITHSHA1ANDDESEDE"] = "PBEWITHSHAAND3-KEYTRIPLEDES-CBC";
+            Algorithms["PBEWITHSHA1AND3-KEYTRIPLEDES-CBC"] = "PBEWITHSHAAND3-KEYTRIPLEDES-CBC";
+            Algorithms["PBEWITHSHAAND3KEYTRIPLEDES"] = "PBEWITHSHAAND3-KEYTRIPLEDES-CBC";
+            Algorithms[PkcsObjectIdentifiers.PbeWithShaAnd3KeyTripleDesCbc.Id] = "PBEWITHSHAAND3-KEYTRIPLEDES-CBC";
+            Algorithms["PBEWITHSHA1ANDDESEDE"] = "PBEWITHSHAAND3-KEYTRIPLEDES-CBC";
 
-            algorithms["PBEWITHSHA1AND2-KEYTRIPLEDES-CBC"] = "PBEWITHSHAAND2-KEYTRIPLEDES-CBC";
-            algorithms[PkcsObjectIdentifiers.PbeWithShaAnd2KeyTripleDesCbc.Id] = "PBEWITHSHAAND2-KEYTRIPLEDES-CBC";
+            Algorithms["PBEWITHSHA1AND2-KEYTRIPLEDES-CBC"] = "PBEWITHSHAAND2-KEYTRIPLEDES-CBC";
+            Algorithms[PkcsObjectIdentifiers.PbeWithShaAnd2KeyTripleDesCbc.Id] = "PBEWITHSHAAND2-KEYTRIPLEDES-CBC";
 
-            algorithms["PBEWITHSHA1AND128BITRC2-CBC"] = "PBEWITHSHAAND128BITRC2-CBC";
-            algorithms[PkcsObjectIdentifiers.PbeWithShaAnd128BitRC2Cbc.Id] = "PBEWITHSHAAND128BITRC2-CBC";
+            Algorithms["PBEWITHSHA1AND128BITRC2-CBC"] = "PBEWITHSHAAND128BITRC2-CBC";
+            Algorithms[PkcsObjectIdentifiers.PbeWithShaAnd128BitRC2Cbc.Id] = "PBEWITHSHAAND128BITRC2-CBC";
 
-            algorithms["PBEWITHSHA1AND40BITRC2-CBC"] = "PBEWITHSHAAND40BITRC2-CBC";
-            algorithms[PkcsObjectIdentifiers.PbewithShaAnd40BitRC2Cbc.Id] = "PBEWITHSHAAND40BITRC2-CBC";
+            Algorithms["PBEWITHSHA1AND40BITRC2-CBC"] = "PBEWITHSHAAND40BITRC2-CBC";
+            Algorithms[PkcsObjectIdentifiers.PbewithShaAnd40BitRC2Cbc.Id] = "PBEWITHSHAAND40BITRC2-CBC";
 
-            algorithms["PBEWITHSHA1AND128BITAES-CBC-BC"] = "PBEWITHSHAAND128BITAES-CBC-BC";
-            algorithms["PBEWITHSHA-1AND128BITAES-CBC-BC"] = "PBEWITHSHAAND128BITAES-CBC-BC";
+            Algorithms["PBEWITHSHA1AND128BITAES-CBC-BC"] = "PBEWITHSHAAND128BITAES-CBC-BC";
+            Algorithms["PBEWITHSHA-1AND128BITAES-CBC-BC"] = "PBEWITHSHAAND128BITAES-CBC-BC";
 
-            algorithms["PBEWITHSHA1AND192BITAES-CBC-BC"] = "PBEWITHSHAAND192BITAES-CBC-BC";
-            algorithms["PBEWITHSHA-1AND192BITAES-CBC-BC"] = "PBEWITHSHAAND192BITAES-CBC-BC";
+            Algorithms["PBEWITHSHA1AND192BITAES-CBC-BC"] = "PBEWITHSHAAND192BITAES-CBC-BC";
+            Algorithms["PBEWITHSHA-1AND192BITAES-CBC-BC"] = "PBEWITHSHAAND192BITAES-CBC-BC";
 
-            algorithms["PBEWITHSHA1AND256BITAES-CBC-BC"] = "PBEWITHSHAAND256BITAES-CBC-BC";
-            algorithms["PBEWITHSHA-1AND256BITAES-CBC-BC"] = "PBEWITHSHAAND256BITAES-CBC-BC";
+            Algorithms["PBEWITHSHA1AND256BITAES-CBC-BC"] = "PBEWITHSHAAND256BITAES-CBC-BC";
+            Algorithms["PBEWITHSHA-1AND256BITAES-CBC-BC"] = "PBEWITHSHAAND256BITAES-CBC-BC";
 
-            algorithms["PBEWITHSHA-256AND128BITAES-CBC-BC"] = "PBEWITHSHA256AND128BITAES-CBC-BC";
-            algorithms["PBEWITHSHA-256AND192BITAES-CBC-BC"] = "PBEWITHSHA256AND192BITAES-CBC-BC";
-            algorithms["PBEWITHSHA-256AND256BITAES-CBC-BC"] = "PBEWITHSHA256AND256BITAES-CBC-BC";
+            Algorithms["PBEWITHSHA-256AND128BITAES-CBC-BC"] = "PBEWITHSHA256AND128BITAES-CBC-BC";
+            Algorithms["PBEWITHSHA-256AND192BITAES-CBC-BC"] = "PBEWITHSHA256AND192BITAES-CBC-BC";
+            Algorithms["PBEWITHSHA-256AND256BITAES-CBC-BC"] = "PBEWITHSHA256AND256BITAES-CBC-BC";
 
 
-            algorithms["GOST"] = "GOST28147";
-            algorithms["GOST-28147"] = "GOST28147";
-            algorithms[CryptoProObjectIdentifiers.GostR28147Cbc.Id] = "GOST28147/CBC/PKCS7PADDING";
+            Algorithms["GOST"] = "GOST28147";
+            Algorithms["GOST-28147"] = "GOST28147";
+            Algorithms[CryptoProObjectIdentifiers.GostR28147Cbc.Id] = "GOST28147/CBC/PKCS7PADDING";
 
-            algorithms["RC5-32"] = "RC5";
+            Algorithms["RC5-32"] = "RC5";
 
-            algorithms[NttObjectIdentifiers.IdCamellia128Cbc.Id] = "CAMELLIA/CBC/PKCS7PADDING";
-            algorithms[NttObjectIdentifiers.IdCamellia192Cbc.Id] = "CAMELLIA/CBC/PKCS7PADDING";
-            algorithms[NttObjectIdentifiers.IdCamellia256Cbc.Id] = "CAMELLIA/CBC/PKCS7PADDING";
+            Algorithms[NttObjectIdentifiers.IdCamellia128Cbc.Id] = "CAMELLIA/CBC/PKCS7PADDING";
+            Algorithms[NttObjectIdentifiers.IdCamellia192Cbc.Id] = "CAMELLIA/CBC/PKCS7PADDING";
+            Algorithms[NttObjectIdentifiers.IdCamellia256Cbc.Id] = "CAMELLIA/CBC/PKCS7PADDING";
 
-            algorithms[KisaObjectIdentifiers.IdSeedCbc.Id] = "SEED/CBC/PKCS7PADDING";
+            Algorithms[KisaObjectIdentifiers.IdSeedCbc.Id] = "SEED/CBC/PKCS7PADDING";
 
-            algorithms["1.3.6.1.4.1.3029.1.2"] = "BLOWFISH/CBC";
+            Algorithms["1.3.6.1.4.1.3029.1.2"] = "BLOWFISH/CBC";
 
-            algorithms["CHACHA20"] = "CHACHA7539";
-            algorithms[PkcsObjectIdentifiers.IdAlgAeadChaCha20Poly1305.Id] = "CHACHA20-POLY1305";
-        }
-
-        private CipherUtilities()
-        {
-        }
-
-        /// <summary>
-        /// Returns a ObjectIdentifier for a give encoding.
-        /// </summary>
-        /// <param name="mechanism">A string representation of the encoding.</param>
-        /// <returns>A DerObjectIdentifier, null if the Oid is not available.</returns>
-        // TODO Don't really want to support this
-        public static DerObjectIdentifier GetObjectIdentifier(
-            string mechanism)
-        {
-            if (mechanism == null)
-                throw new ArgumentNullException("mechanism");
-
-            mechanism = Platform.ToUpperInvariant(mechanism);
-            string aliased = (string) algorithms[mechanism];
-
-            if (aliased != null)
-                mechanism = aliased;
-
-            return (DerObjectIdentifier) oids[mechanism];
-        }
-
-        public static ICollection Algorithms
-        {
-            get { return oids.Keys; }
+            Algorithms["CHACHA20"] = "CHACHA7539";
+            Algorithms[PkcsObjectIdentifiers.IdAlgAeadChaCha20Poly1305.Id] = "CHACHA20-POLY1305";
         }
 
         public static IBufferedCipher GetCipher(
@@ -297,20 +268,12 @@ namespace Org.BouncyCastle.Security
             return GetCipher(oid.Id);
         }
 
-        public static IBufferedCipher GetCipher(
-            string algorithm)
+        public static IBufferedCipher GetCipher(string algorithm)
         {
             if (algorithm == null)
-                throw new ArgumentNullException("algorithm");
+                throw new ArgumentNullException(nameof(algorithm));
 
-            algorithm = Platform.ToUpperInvariant(algorithm);
-
-            {
-                string aliased = (string) algorithms[algorithm];
-
-                if (aliased != null)
-                    algorithm = aliased;
-            }
+            algorithm = CollectionUtilities.GetValueOrKey(Algorithms, algorithm).ToUpperInvariant();
 
             IBasicAgreement iesAgreement = null;
             if (algorithm == "IES")
@@ -390,14 +353,7 @@ namespace Org.BouncyCastle.Security
             IAsymmetricBlockCipher asymBlockCipher = null;
             IStreamCipher streamCipher = null;
 
-            string algorithmName = parts[0];
-
-            {
-                string aliased = (string)algorithms[algorithmName];
-
-                if (aliased != null)
-                    algorithmName = aliased;
-            }
+            string algorithmName = CollectionUtilities.GetValueOrKey(Algorithms, parts[0]).ToUpperInvariant();
 
             CipherAlgorithm cipherAlgorithm;
             try
@@ -411,126 +367,126 @@ namespace Org.BouncyCastle.Security
 
             switch (cipherAlgorithm)
             {
-                case CipherAlgorithm.AES:
-                    blockCipher = new AesEngine();
-                    break;
-                case CipherAlgorithm.ARC4:
-                    streamCipher = new RC4Engine();
-                    break;
-                case CipherAlgorithm.ARIA:
-                    blockCipher = new AriaEngine();
-                    break;
-                case CipherAlgorithm.BLOWFISH:
-                    blockCipher = new BlowfishEngine();
-                    break;
-                case CipherAlgorithm.CAMELLIA:
-                    blockCipher = new CamelliaEngine();
-                    break;
-                case CipherAlgorithm.CAST5:
-                    blockCipher = new Cast5Engine();
-                    break;
-                case CipherAlgorithm.CAST6:
-                    blockCipher = new Cast6Engine();
-                    break;
-                case CipherAlgorithm.CHACHA:
-                    streamCipher = new ChaChaEngine();
-                    break;
-                case CipherAlgorithm.CHACHA20_POLY1305:
-                    aeadCipher = new ChaCha20Poly1305();
-                    break;
-                case CipherAlgorithm.CHACHA7539:
-                    streamCipher = new ChaCha7539Engine();
-                    break;
-                case CipherAlgorithm.DES:
-                    blockCipher = new DesEngine();
-                    break;
-                case CipherAlgorithm.DESEDE:
-                    blockCipher = new DesEdeEngine();
-                    break;
-                case CipherAlgorithm.ELGAMAL:
-                    asymBlockCipher = new ElGamalEngine();
-                    break;
-                case CipherAlgorithm.GOST28147:
-                    blockCipher = new Gost28147Engine();
-                    break;
-                case CipherAlgorithm.HC128:
-                    streamCipher = new HC128Engine();
-                    break;
-                case CipherAlgorithm.HC256:
-                    streamCipher = new HC256Engine();
-                    break;
-                case CipherAlgorithm.IDEA:
-                    blockCipher = new IdeaEngine();
-                    break;
-                case CipherAlgorithm.NOEKEON:
-                    blockCipher = new NoekeonEngine();
-                    break;
-                case CipherAlgorithm.PBEWITHSHAAND128BITRC4:
-                case CipherAlgorithm.PBEWITHSHAAND40BITRC4:
-                    streamCipher = new RC4Engine();
-                    break;
-                case CipherAlgorithm.RC2:
-                    blockCipher = new RC2Engine();
-                    break;
-                case CipherAlgorithm.RC5:
-                    blockCipher = new RC532Engine();
-                    break;
-                case CipherAlgorithm.RC5_64:
-                    blockCipher = new RC564Engine();
-                    break;
-                case CipherAlgorithm.RC6:
-                    blockCipher = new RC6Engine();
-                    break;
-                case CipherAlgorithm.RIJNDAEL:
-                    blockCipher = new RijndaelEngine();
-                    break;
-                case CipherAlgorithm.RSA:
-                    asymBlockCipher = new RsaBlindedEngine();
-                    break;
-                case CipherAlgorithm.SALSA20:
-                    streamCipher = new Salsa20Engine();
-                    break;
-                case CipherAlgorithm.SEED:
-                    blockCipher = new SeedEngine();
-                    break;
-                case CipherAlgorithm.SERPENT:
-                    blockCipher = new SerpentEngine();
-                    break;
-                case CipherAlgorithm.SKIPJACK:
-                    blockCipher = new SkipjackEngine();
-                    break;
-                case CipherAlgorithm.SM4:
-                    blockCipher = new SM4Engine();
-                    break;
-                case CipherAlgorithm.TEA:
-                    blockCipher = new TeaEngine();
-                    break;
-                case CipherAlgorithm.THREEFISH_256:
-                    blockCipher = new ThreefishEngine(ThreefishEngine.BLOCKSIZE_256);
-                    break;
-                case CipherAlgorithm.THREEFISH_512:
-                    blockCipher = new ThreefishEngine(ThreefishEngine.BLOCKSIZE_512);
-                    break;
-                case CipherAlgorithm.THREEFISH_1024:
-                    blockCipher = new ThreefishEngine(ThreefishEngine.BLOCKSIZE_1024);
-                    break;
-                case CipherAlgorithm.TNEPRES:
-                    blockCipher = new TnepresEngine();
-                    break;
-                case CipherAlgorithm.TWOFISH:
-                    blockCipher = new TwofishEngine();
-                    break;
-                case CipherAlgorithm.VMPC:
-                    streamCipher = new VmpcEngine();
-                    break;
-                case CipherAlgorithm.VMPC_KSA3:
-                    streamCipher = new VmpcKsa3Engine();
-                    break;
-                case CipherAlgorithm.XTEA:
-                    blockCipher = new XteaEngine();
-                    break;
-                default:
-                    throw new SecurityUtilityException("Cipher " + algorithm + " not recognised.");
+            case CipherAlgorithm.AES:
+                blockCipher = new AesEngine();
+                break;
+            case CipherAlgorithm.ARC4:
+                streamCipher = new RC4Engine();
+                break;
+            case CipherAlgorithm.ARIA:
+                blockCipher = new AriaEngine();
+                break;
+            case CipherAlgorithm.BLOWFISH:
+                blockCipher = new BlowfishEngine();
+                break;
+            case CipherAlgorithm.CAMELLIA:
+                blockCipher = new CamelliaEngine();
+                break;
+            case CipherAlgorithm.CAST5:
+                blockCipher = new Cast5Engine();
+                break;
+            case CipherAlgorithm.CAST6:
+                blockCipher = new Cast6Engine();
+                break;
+            case CipherAlgorithm.CHACHA:
+                streamCipher = new ChaChaEngine();
+                break;
+            case CipherAlgorithm.CHACHA20_POLY1305:
+                aeadCipher = new ChaCha20Poly1305();
+                break;
+            case CipherAlgorithm.CHACHA7539:
+                streamCipher = new ChaCha7539Engine();
+                break;
+            case CipherAlgorithm.DES:
+                blockCipher = new DesEngine();
+                break;
+            case CipherAlgorithm.DESEDE:
+                blockCipher = new DesEdeEngine();
+                break;
+            case CipherAlgorithm.ELGAMAL:
+                asymBlockCipher = new ElGamalEngine();
+                break;
+            case CipherAlgorithm.GOST28147:
+                blockCipher = new Gost28147Engine();
+                break;
+            case CipherAlgorithm.HC128:
+                streamCipher = new HC128Engine();
+                break;
+            case CipherAlgorithm.HC256:
+                streamCipher = new HC256Engine();
+                break;
+            case CipherAlgorithm.IDEA:
+                blockCipher = new IdeaEngine();
+                break;
+            case CipherAlgorithm.NOEKEON:
+                blockCipher = new NoekeonEngine();
+                break;
+            case CipherAlgorithm.PBEWITHSHAAND128BITRC4:
+            case CipherAlgorithm.PBEWITHSHAAND40BITRC4:
+                streamCipher = new RC4Engine();
+                break;
+            case CipherAlgorithm.RC2:
+                blockCipher = new RC2Engine();
+                break;
+            case CipherAlgorithm.RC5:
+                blockCipher = new RC532Engine();
+                break;
+            case CipherAlgorithm.RC5_64:
+                blockCipher = new RC564Engine();
+                break;
+            case CipherAlgorithm.RC6:
+                blockCipher = new RC6Engine();
+                break;
+            case CipherAlgorithm.RIJNDAEL:
+                blockCipher = new RijndaelEngine();
+                break;
+            case CipherAlgorithm.RSA:
+                asymBlockCipher = new RsaBlindedEngine();
+                break;
+            case CipherAlgorithm.SALSA20:
+                streamCipher = new Salsa20Engine();
+                break;
+            case CipherAlgorithm.SEED:
+                blockCipher = new SeedEngine();
+                break;
+            case CipherAlgorithm.SERPENT:
+                blockCipher = new SerpentEngine();
+                break;
+            case CipherAlgorithm.SKIPJACK:
+                blockCipher = new SkipjackEngine();
+                break;
+            case CipherAlgorithm.SM4:
+                blockCipher = new SM4Engine();
+                break;
+            case CipherAlgorithm.TEA:
+                blockCipher = new TeaEngine();
+                break;
+            case CipherAlgorithm.THREEFISH_256:
+                blockCipher = new ThreefishEngine(ThreefishEngine.BLOCKSIZE_256);
+                break;
+            case CipherAlgorithm.THREEFISH_512:
+                blockCipher = new ThreefishEngine(ThreefishEngine.BLOCKSIZE_512);
+                break;
+            case CipherAlgorithm.THREEFISH_1024:
+                blockCipher = new ThreefishEngine(ThreefishEngine.BLOCKSIZE_1024);
+                break;
+            case CipherAlgorithm.TNEPRES:
+                blockCipher = new TnepresEngine();
+                break;
+            case CipherAlgorithm.TWOFISH:
+                blockCipher = new TwofishEngine();
+                break;
+            case CipherAlgorithm.VMPC:
+                streamCipher = new VmpcEngine();
+                break;
+            case CipherAlgorithm.VMPC_KSA3:
+                streamCipher = new VmpcKsa3Engine();
+                break;
+            case CipherAlgorithm.XTEA:
+                blockCipher = new XteaEngine();
+                break;
+            default:
+                throw new SecurityUtilityException("Cipher " + algorithm + " not recognised.");
             }
 
             if (aeadCipher != null)
@@ -585,81 +541,81 @@ namespace Org.BouncyCastle.Security
 
                 switch (cipherPadding)
                 {
-                    case CipherPadding.NOPADDING:
-                        padded = false;
-                        break;
-                    case CipherPadding.RAW:
-                        break;
-                    case CipherPadding.ISO10126PADDING:
-                    case CipherPadding.ISO10126D2PADDING:
-                    case CipherPadding.ISO10126_2PADDING:
-                        padding = new ISO10126d2Padding();
-                        break;
-                    case CipherPadding.ISO7816_4PADDING:
-                    case CipherPadding.ISO9797_1PADDING:
-                        padding = new ISO7816d4Padding();
-                        break;
-                    case CipherPadding.ISO9796_1:
-                    case CipherPadding.ISO9796_1PADDING:
-                        asymBlockCipher = new ISO9796d1Encoding(asymBlockCipher);
-                        break;
-                    case CipherPadding.OAEP:
-                    case CipherPadding.OAEPPADDING:
-                        asymBlockCipher = new OaepEncoding(asymBlockCipher);
-                        break;
-                    case CipherPadding.OAEPWITHMD5ANDMGF1PADDING:
-                        asymBlockCipher = new OaepEncoding(asymBlockCipher, new MD5Digest());
-                        break;
-                    case CipherPadding.OAEPWITHSHA1ANDMGF1PADDING:
-                    case CipherPadding.OAEPWITHSHA_1ANDMGF1PADDING:
-                        asymBlockCipher = new OaepEncoding(asymBlockCipher, new Sha1Digest());
-                        break;
-                    case CipherPadding.OAEPWITHSHA224ANDMGF1PADDING:
-                    case CipherPadding.OAEPWITHSHA_224ANDMGF1PADDING:
-                        asymBlockCipher = new OaepEncoding(asymBlockCipher, new Sha224Digest());
-                        break;
-                    case CipherPadding.OAEPWITHSHA256ANDMGF1PADDING:
-                    case CipherPadding.OAEPWITHSHA_256ANDMGF1PADDING:
-                    case CipherPadding.OAEPWITHSHA256ANDMGF1WITHSHA256PADDING:
-                    case CipherPadding.OAEPWITHSHA_256ANDMGF1WITHSHA_256PADDING:
-                        asymBlockCipher = new OaepEncoding(asymBlockCipher, new Sha256Digest());
-                        break;
-                    case CipherPadding.OAEPWITHSHA256ANDMGF1WITHSHA1PADDING:
-                    case CipherPadding.OAEPWITHSHA_256ANDMGF1WITHSHA_1PADDING:
-                        asymBlockCipher = new OaepEncoding(asymBlockCipher, new Sha256Digest(), new Sha1Digest(), null);
-                        break;
-                    case CipherPadding.OAEPWITHSHA384ANDMGF1PADDING:
-                    case CipherPadding.OAEPWITHSHA_384ANDMGF1PADDING:
-                        asymBlockCipher = new OaepEncoding(asymBlockCipher, new Sha384Digest());
-                        break;
-                    case CipherPadding.OAEPWITHSHA512ANDMGF1PADDING:
-                    case CipherPadding.OAEPWITHSHA_512ANDMGF1PADDING:
-                        asymBlockCipher = new OaepEncoding(asymBlockCipher, new Sha512Digest());
-                        break;
-                    case CipherPadding.PKCS1:
-                    case CipherPadding.PKCS1PADDING:
-                        asymBlockCipher = new Pkcs1Encoding(asymBlockCipher);
-                        break;
-                    case CipherPadding.PKCS5:
-                    case CipherPadding.PKCS5PADDING:
-                    case CipherPadding.PKCS7:
-                    case CipherPadding.PKCS7PADDING:
-                        padding = new Pkcs7Padding();
-                        break;
-                    case CipherPadding.TBCPADDING:
-                        padding = new TbcPadding();
-                        break;
-                    case CipherPadding.WITHCTS:
-                        cts = true;
-                        break;
-                    case CipherPadding.X923PADDING:
-                        padding = new X923Padding();
-                        break;
-                    case CipherPadding.ZEROBYTEPADDING:
-                        padding = new ZeroBytePadding();
-                        break;
-                    default:
-                        throw new SecurityUtilityException("Cipher " + algorithm + " not recognised.");
+                case CipherPadding.NOPADDING:
+                    padded = false;
+                    break;
+                case CipherPadding.RAW:
+                    break;
+                case CipherPadding.ISO10126PADDING:
+                case CipherPadding.ISO10126D2PADDING:
+                case CipherPadding.ISO10126_2PADDING:
+                    padding = new ISO10126d2Padding();
+                    break;
+                case CipherPadding.ISO7816_4PADDING:
+                case CipherPadding.ISO9797_1PADDING:
+                    padding = new ISO7816d4Padding();
+                    break;
+                case CipherPadding.ISO9796_1:
+                case CipherPadding.ISO9796_1PADDING:
+                    asymBlockCipher = new ISO9796d1Encoding(asymBlockCipher);
+                    break;
+                case CipherPadding.OAEP:
+                case CipherPadding.OAEPPADDING:
+                    asymBlockCipher = new OaepEncoding(asymBlockCipher);
+                    break;
+                case CipherPadding.OAEPWITHMD5ANDMGF1PADDING:
+                    asymBlockCipher = new OaepEncoding(asymBlockCipher, new MD5Digest());
+                    break;
+                case CipherPadding.OAEPWITHSHA1ANDMGF1PADDING:
+                case CipherPadding.OAEPWITHSHA_1ANDMGF1PADDING:
+                    asymBlockCipher = new OaepEncoding(asymBlockCipher, new Sha1Digest());
+                    break;
+                case CipherPadding.OAEPWITHSHA224ANDMGF1PADDING:
+                case CipherPadding.OAEPWITHSHA_224ANDMGF1PADDING:
+                    asymBlockCipher = new OaepEncoding(asymBlockCipher, new Sha224Digest());
+                    break;
+                case CipherPadding.OAEPWITHSHA256ANDMGF1PADDING:
+                case CipherPadding.OAEPWITHSHA_256ANDMGF1PADDING:
+                case CipherPadding.OAEPWITHSHA256ANDMGF1WITHSHA256PADDING:
+                case CipherPadding.OAEPWITHSHA_256ANDMGF1WITHSHA_256PADDING:
+                    asymBlockCipher = new OaepEncoding(asymBlockCipher, new Sha256Digest());
+                    break;
+                case CipherPadding.OAEPWITHSHA256ANDMGF1WITHSHA1PADDING:
+                case CipherPadding.OAEPWITHSHA_256ANDMGF1WITHSHA_1PADDING:
+                    asymBlockCipher = new OaepEncoding(asymBlockCipher, new Sha256Digest(), new Sha1Digest(), null);
+                    break;
+                case CipherPadding.OAEPWITHSHA384ANDMGF1PADDING:
+                case CipherPadding.OAEPWITHSHA_384ANDMGF1PADDING:
+                    asymBlockCipher = new OaepEncoding(asymBlockCipher, new Sha384Digest());
+                    break;
+                case CipherPadding.OAEPWITHSHA512ANDMGF1PADDING:
+                case CipherPadding.OAEPWITHSHA_512ANDMGF1PADDING:
+                    asymBlockCipher = new OaepEncoding(asymBlockCipher, new Sha512Digest());
+                    break;
+                case CipherPadding.PKCS1:
+                case CipherPadding.PKCS1PADDING:
+                    asymBlockCipher = new Pkcs1Encoding(asymBlockCipher);
+                    break;
+                case CipherPadding.PKCS5:
+                case CipherPadding.PKCS5PADDING:
+                case CipherPadding.PKCS7:
+                case CipherPadding.PKCS7PADDING:
+                    padding = new Pkcs7Padding();
+                    break;
+                case CipherPadding.TBCPADDING:
+                    padding = new TbcPadding();
+                    break;
+                case CipherPadding.WITHCTS:
+                    cts = true;
+                    break;
+                case CipherPadding.X923PADDING:
+                    padding = new X923Padding();
+                    break;
+                case CipherPadding.ZEROBYTEPADDING:
+                    padding = new ZeroBytePadding();
+                    break;
+                default:
+                    throw new SecurityUtilityException("Cipher " + algorithm + " not recognised.");
                 }
             }
 
@@ -679,64 +635,64 @@ namespace Org.BouncyCastle.Security
 
                     switch (cipherMode)
                     {
-                        case CipherMode.ECB:
-                        case CipherMode.NONE:
-                            break;
-                        case CipherMode.CBC:
-                            blockCipher = new CbcBlockCipher(blockCipher);
-                            break;
-                        case CipherMode.CCM:
-                            aeadBlockCipher = new CcmBlockCipher(blockCipher);
-                            break;
-                        case CipherMode.CFB:
-                        {
-                            int bits = (di < 0)
-                                ?	8 * blockCipher.GetBlockSize()
-                                :	int.Parse(mode.Substring(di));
+                    case CipherMode.ECB:
+                    case CipherMode.NONE:
+                        break;
+                    case CipherMode.CBC:
+                        blockCipher = new CbcBlockCipher(blockCipher);
+                        break;
+                    case CipherMode.CCM:
+                        aeadBlockCipher = new CcmBlockCipher(blockCipher);
+                        break;
+                    case CipherMode.CFB:
+                    {
+                        int bits = (di < 0)
+                            ?	8 * blockCipher.GetBlockSize()
+                            :	int.Parse(mode.Substring(di));
     
-                            blockCipher = new CfbBlockCipher(blockCipher, bits);
-                            break;
-                        }
-                        case CipherMode.CTR:
-                            blockCipher = new SicBlockCipher(blockCipher);
-                            break;
-                        case CipherMode.CTS:
-                            cts = true;
-                            blockCipher = new CbcBlockCipher(blockCipher);
-                            break;
-                        case CipherMode.EAX:
-                            aeadBlockCipher = new EaxBlockCipher(blockCipher);
-                            break;
-                        case CipherMode.GCM:
-                            aeadBlockCipher = new GcmBlockCipher(blockCipher);
-                            break;
-                        case CipherMode.GOFB:
-                            blockCipher = new GOfbBlockCipher(blockCipher);
-                            break;
-                        case CipherMode.OCB:
-                            aeadBlockCipher = new OcbBlockCipher(blockCipher, CreateBlockCipher(cipherAlgorithm));
-                            break;
-                        case CipherMode.OFB:
-                        {
-                            int bits = (di < 0)
-                                ?	8 * blockCipher.GetBlockSize()
-                                :	int.Parse(mode.Substring(di));
+                        blockCipher = new CfbBlockCipher(blockCipher, bits);
+                        break;
+                    }
+                    case CipherMode.CTR:
+                        blockCipher = new SicBlockCipher(blockCipher);
+                        break;
+                    case CipherMode.CTS:
+                        cts = true;
+                        blockCipher = new CbcBlockCipher(blockCipher);
+                        break;
+                    case CipherMode.EAX:
+                        aeadBlockCipher = new EaxBlockCipher(blockCipher);
+                        break;
+                    case CipherMode.GCM:
+                        aeadBlockCipher = new GcmBlockCipher(blockCipher);
+                        break;
+                    case CipherMode.GOFB:
+                        blockCipher = new GOfbBlockCipher(blockCipher);
+                        break;
+                    case CipherMode.OCB:
+                        aeadBlockCipher = new OcbBlockCipher(blockCipher, CreateBlockCipher(cipherAlgorithm));
+                        break;
+                    case CipherMode.OFB:
+                    {
+                        int bits = (di < 0)
+                            ?	8 * blockCipher.GetBlockSize()
+                            :	int.Parse(mode.Substring(di));
     
-                            blockCipher = new OfbBlockCipher(blockCipher, bits);
-                            break;
+                        blockCipher = new OfbBlockCipher(blockCipher, bits);
+                        break;
+                    }
+                    case CipherMode.OPENPGPCFB:
+                        blockCipher = new OpenPgpCfbBlockCipher(blockCipher);
+                        break;
+                    case CipherMode.SIC:
+                        if (blockCipher.GetBlockSize() < 16)
+                        {
+                            throw new ArgumentException("Warning: SIC-Mode can become a twotime-pad if the blocksize of the cipher is too small. Use a cipher with a block size of at least 128 bits (e.g. AES)");
                         }
-                        case CipherMode.OPENPGPCFB:
-                            blockCipher = new OpenPgpCfbBlockCipher(blockCipher);
-                            break;
-                        case CipherMode.SIC:
-                            if (blockCipher.GetBlockSize() < 16)
-                            {
-                                throw new ArgumentException("Warning: SIC-Mode can become a twotime-pad if the blocksize of the cipher is too small. Use a cipher with a block size of at least 128 bits (e.g. AES)");
-                            }
-                            blockCipher = new SicBlockCipher(blockCipher);
-                            break;
-                        default:
-                            throw new SecurityUtilityException("Cipher " + algorithm + " not recognised.");
+                        blockCipher = new SicBlockCipher(blockCipher);
+                        break;
+                    default:
+                        throw new SecurityUtilityException("Cipher " + algorithm + " not recognised.");
                     }
                 }
                 catch (ArgumentException)
@@ -783,14 +739,12 @@ namespace Org.BouncyCastle.Security
             throw new SecurityUtilityException("Cipher " + algorithm + " not recognised.");
         }
 
-        public static string GetAlgorithmName(
-            DerObjectIdentifier oid)
+        public static string GetAlgorithmName(DerObjectIdentifier oid)
         {
-            return (string) algorithms[oid.Id];
+            return CollectionUtilities.GetValueOrNull(Algorithms, oid.Id);
         }
 
-        private static int GetDigitIndex(
-            string s)
+        private static int GetDigitIndex(string s)
         {
             for (int i = 0; i < s.Length; ++i)
             {
@@ -805,35 +759,35 @@ namespace Org.BouncyCastle.Security
         {
             switch (cipherAlgorithm)
             {
-                case CipherAlgorithm.AES: return new AesEngine();
-                case CipherAlgorithm.ARIA: return new AriaEngine();
-                case CipherAlgorithm.BLOWFISH: return new BlowfishEngine();
-                case CipherAlgorithm.CAMELLIA: return new CamelliaEngine();
-                case CipherAlgorithm.CAST5: return new Cast5Engine();
-                case CipherAlgorithm.CAST6: return new Cast6Engine();
-                case CipherAlgorithm.DES: return new DesEngine();
-                case CipherAlgorithm.DESEDE: return new DesEdeEngine();
-                case CipherAlgorithm.GOST28147: return new Gost28147Engine();
-                case CipherAlgorithm.IDEA: return new IdeaEngine();
-                case CipherAlgorithm.NOEKEON: return new NoekeonEngine();
-                case CipherAlgorithm.RC2: return new RC2Engine();
-                case CipherAlgorithm.RC5: return new RC532Engine();
-                case CipherAlgorithm.RC5_64: return new RC564Engine();
-                case CipherAlgorithm.RC6: return new RC6Engine();
-                case CipherAlgorithm.RIJNDAEL: return new RijndaelEngine();
-                case CipherAlgorithm.SEED: return new SeedEngine();
-                case CipherAlgorithm.SERPENT: return new SerpentEngine();
-                case CipherAlgorithm.SKIPJACK: return new SkipjackEngine();
-                case CipherAlgorithm.SM4: return new SM4Engine();
-                case CipherAlgorithm.TEA: return new TeaEngine();
-                case CipherAlgorithm.THREEFISH_256: return new ThreefishEngine(ThreefishEngine.BLOCKSIZE_256);
-                case CipherAlgorithm.THREEFISH_512: return new ThreefishEngine(ThreefishEngine.BLOCKSIZE_512);
-                case CipherAlgorithm.THREEFISH_1024: return new ThreefishEngine(ThreefishEngine.BLOCKSIZE_1024);
-                case CipherAlgorithm.TNEPRES: return new TnepresEngine();
-                case CipherAlgorithm.TWOFISH: return new TwofishEngine();
-                case CipherAlgorithm.XTEA: return new XteaEngine();
-                default:
-                    throw new SecurityUtilityException("Cipher " + cipherAlgorithm + " not recognised or not a block cipher");
+            case CipherAlgorithm.AES: return new AesEngine();
+            case CipherAlgorithm.ARIA: return new AriaEngine();
+            case CipherAlgorithm.BLOWFISH: return new BlowfishEngine();
+            case CipherAlgorithm.CAMELLIA: return new CamelliaEngine();
+            case CipherAlgorithm.CAST5: return new Cast5Engine();
+            case CipherAlgorithm.CAST6: return new Cast6Engine();
+            case CipherAlgorithm.DES: return new DesEngine();
+            case CipherAlgorithm.DESEDE: return new DesEdeEngine();
+            case CipherAlgorithm.GOST28147: return new Gost28147Engine();
+            case CipherAlgorithm.IDEA: return new IdeaEngine();
+            case CipherAlgorithm.NOEKEON: return new NoekeonEngine();
+            case CipherAlgorithm.RC2: return new RC2Engine();
+            case CipherAlgorithm.RC5: return new RC532Engine();
+            case CipherAlgorithm.RC5_64: return new RC564Engine();
+            case CipherAlgorithm.RC6: return new RC6Engine();
+            case CipherAlgorithm.RIJNDAEL: return new RijndaelEngine();
+            case CipherAlgorithm.SEED: return new SeedEngine();
+            case CipherAlgorithm.SERPENT: return new SerpentEngine();
+            case CipherAlgorithm.SKIPJACK: return new SkipjackEngine();
+            case CipherAlgorithm.SM4: return new SM4Engine();
+            case CipherAlgorithm.TEA: return new TeaEngine();
+            case CipherAlgorithm.THREEFISH_256: return new ThreefishEngine(ThreefishEngine.BLOCKSIZE_256);
+            case CipherAlgorithm.THREEFISH_512: return new ThreefishEngine(ThreefishEngine.BLOCKSIZE_512);
+            case CipherAlgorithm.THREEFISH_1024: return new ThreefishEngine(ThreefishEngine.BLOCKSIZE_1024);
+            case CipherAlgorithm.TNEPRES: return new TnepresEngine();
+            case CipherAlgorithm.TWOFISH: return new TwofishEngine();
+            case CipherAlgorithm.XTEA: return new XteaEngine();
+            default:
+                throw new SecurityUtilityException("Cipher " + cipherAlgorithm + " not recognised or not a block cipher");
             }
         }
     }