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fredericDelaportefredericDelaporte
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Cease using cryptographic hashes
Under Windows, cryptographic hash may be rejected if FIPS is enabled and the used algorithm is not FIPS compliant. Fix #32 by the way
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14 files changed

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-165
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14 files changed

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-165
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‎CommonInternals/Hasher.cs

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/*
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* Derived from MurmurHash2Simple,
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* http://landman-code.blogspot.com/2009/02/c-superfasthash-and-murmurhash2.html
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*/
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/***** BEGIN LICENSE BLOCK *****
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* Version: MPL 1.1/GPL 2.0/LGPL 2.1
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*
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* The contents of this file are subject to the Mozilla Public License Version
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* 1.1 (the "License"); you may not use this file except in compliance with
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* the License. You may obtain a copy of the License at
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* http://www.mozilla.org/MPL/
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*
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* Software distributed under the License is distributed on an "AS IS" basis,
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* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
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* for the specific language governing rights and limitations under the
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* License.
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*
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* The Original Code is HashTableHashing.MurmurHash2.
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*
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* The Initial Developer of the Original Code is
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* Davy Landman.
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* Portions created by the Initial Developer are Copyright (C) 2009
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* the Initial Developer. All Rights Reserved.
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*
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* Contributor(s):
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*
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*
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* Alternatively, the contents of this file may be used under the terms of
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* either the GNU General Public License Version 2 or later (the "GPL"), or
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* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
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* in which case the provisions of the GPL or the LGPL are applicable instead
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* of those above. If you wish to allow use of your version of this file only
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* under the terms of either the GPL or the LGPL, and not to allow others to
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* use your version of this file under the terms of the MPL, indicate your
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* decision by deleting the provisions above and replace them with the notice
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* and other provisions required by the GPL or the LGPL. If you do not delete
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* the provisions above, a recipient may use your version of this file under
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* the terms of any one of the MPL, the GPL or the LGPL.
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*
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* ***** END LICENSE BLOCK ***** */
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using System;
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using System.Text;
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namespace NHibernate.Caches.Util
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{
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/// <summary>A stable hasher using MurmurHash2 algorithm.</summary>
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internal static class Hasher
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{
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internal static string HashToString(string input)
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{
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var hash = Hash(input);
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return hash.ToString("X");
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}
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internal static uint Hash(string input)
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{
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return Hash(Encoding.UTF8.GetBytes(input));
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}
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internal static uint Hash(byte[] data)
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{
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return Hash(data, 0xc58f1a7b);
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}
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private const uint _m = 0x5bd1e995;
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private const int _r = 24;
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internal static uint Hash(byte[] data, uint seed)
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{
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var length = data.Length;
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if (length == 0)
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return 0;
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var h = seed ^ (uint) length;
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var currentIndex = 0;
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while (length >= 4)
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{
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var k = BitConverter.ToUInt32(data, currentIndex);
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k *= _m;
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k ^= k >> _r;
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k *= _m;
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h *= _m;
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h ^= k;
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currentIndex += 4;
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length -= 4;
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}
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switch (length)
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{
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case 3:
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h ^= BitConverter.ToUInt16(data, currentIndex);
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h ^= (uint) data[currentIndex + 2] << 16;
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h *= _m;
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break;
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case 2:
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h ^= BitConverter.ToUInt16(data, currentIndex);
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h *= _m;
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break;
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case 1:
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h ^= data[currentIndex];
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h *= _m;
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break;
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}
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// Do a few final mixes of the hash to ensure the last few
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// bytes are well-incorporated.
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h ^= h >> 13;
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h *= _m;
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h ^= h >> 15;
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return h;
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}
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}
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}

‎CoreDistributedCache/NHibernate.Caches.CoreDistributedCache.Memcached/NHibernate.Caches.CoreDistributedCache.Memcached.csproj

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@@ -8,11 +8,8 @@
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<TargetFrameworks>net461;netstandard2.0</TargetFrameworks>
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<SignAssembly>False</SignAssembly>
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<GenerateDocumentationFile>true</GenerateDocumentationFile>
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<PackageReleaseNotes>* New feature
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* #47 - Add an option for appending hashcode to key
13-
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* Task
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* #46 - Update NHibernate to 5.1.0</PackageReleaseNotes>
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<PackageReleaseNotes>* Improvement
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* #52 - Cease using cryptographic hashes</PackageReleaseNotes>
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</PropertyGroup>
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<PropertyGroup Condition="'$(TargetFramework)' == 'net461'">
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<DefineConstants>NETFX;$(DefineConstants)</DefineConstants>

‎CoreDistributedCache/NHibernate.Caches.CoreDistributedCache.Memory/NHibernate.Caches.CoreDistributedCache.Memory.csproj

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@@ -10,11 +10,8 @@ Meant for testing purpose, consider NHibernate.Caches.CoreMemoryCache for other
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<SignAssembly>True</SignAssembly>
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<AssemblyOriginatorKeyFile>..\..\NHibernate.Caches.snk</AssemblyOriginatorKeyFile>
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<GenerateDocumentationFile>true</GenerateDocumentationFile>
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<PackageReleaseNotes>* New feature
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* #47 - Add an option for appending hashcode to key
15-
16-
* Task
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* #46 - Update NHibernate to 5.1.0</PackageReleaseNotes>
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<PackageReleaseNotes>* Improvement
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* #52 - Cease using cryptographic hashes</PackageReleaseNotes>
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</PropertyGroup>
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<PropertyGroup Condition="'$(TargetFramework)' == 'net461'">
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<DefineConstants>NETFX;$(DefineConstants)</DefineConstants>

‎CoreDistributedCache/NHibernate.Caches.CoreDistributedCache.Redis/NHibernate.Caches.CoreDistributedCache.Redis.csproj

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@@ -9,11 +9,8 @@
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<SignAssembly>True</SignAssembly>
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<AssemblyOriginatorKeyFile>..\..\NHibernate.Caches.snk</AssemblyOriginatorKeyFile>
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<GenerateDocumentationFile>true</GenerateDocumentationFile>
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<PackageReleaseNotes>* New feature
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* #47 - Add an option for appending hashcode to key
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* Task
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* #46 - Update NHibernate to 5.1.0</PackageReleaseNotes>
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<PackageReleaseNotes>* Improvement
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* #52 - Cease using cryptographic hashes</PackageReleaseNotes>
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</PropertyGroup>
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<PropertyGroup Condition="'$(TargetFramework)' == 'net461'">
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<DefineConstants>NETFX;$(DefineConstants)</DefineConstants>

‎CoreDistributedCache/NHibernate.Caches.CoreDistributedCache.SqlServer/NHibernate.Caches.CoreDistributedCache.SqlServer.csproj

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<SignAssembly>True</SignAssembly>
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<AssemblyOriginatorKeyFile>..\..\NHibernate.Caches.snk</AssemblyOriginatorKeyFile>
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<GenerateDocumentationFile>true</GenerateDocumentationFile>
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<PackageReleaseNotes>* New feature
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* #47 - Add an option for appending hashcode to key
14-
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* Task
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* #46 - Update NHibernate to 5.1.0</PackageReleaseNotes>
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<PackageReleaseNotes>* Improvement
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* #52 - Cease using cryptographic hashes</PackageReleaseNotes>
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</PropertyGroup>
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<PropertyGroup Condition="'$(TargetFramework)' == 'net461'">
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<DefineConstants>NETFX;$(DefineConstants)</DefineConstants>

‎CoreDistributedCache/NHibernate.Caches.CoreDistributedCache/Async/CoreDistributedCache.cs

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@@ -13,9 +13,8 @@
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using System.Collections.Generic;
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using System.IO;
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using System.Runtime.Serialization.Formatters.Binary;
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using System.Security.Cryptography;
17-
using System.Text;
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using Microsoft.Extensions.Caching.Distributed;
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using NHibernate.Caches.Util;
1918
using NHibernate.Util;
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namespace NHibernate.Caches.CoreDistributedCache

‎CoreDistributedCache/NHibernate.Caches.CoreDistributedCache/CoreDistributedCache.cs

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using System.Collections.Generic;
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using System.IO;
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using System.Runtime.Serialization.Formatters.Binary;
28-
using System.Security.Cryptography;
29-
using System.Text;
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using Microsoft.Extensions.Caching.Distributed;
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using NHibernate.Caches.Util;
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using NHibernate.Util;
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namespace NHibernate.Caches.CoreDistributedCache
@@ -175,24 +174,18 @@ private static bool GetUseSlidingExpiration(IDictionary<string, string> props)
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private string GetCacheKey(object key)
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{
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var baseKey = _cacheKeyPrefix + _fullRegion + ":" + key;
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var keyAsString = AppendHashcodeToKey
179-
? string.Concat(_cacheKeyPrefix, _fullRegion, ":", key.ToString(), "@", key.GetHashCode())
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: string.Concat(_cacheKeyPrefix, _fullRegion, ":", key.ToString());
179+
? baseKey + "@" + key.GetHashCode()
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: baseKey;
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182182
if (_maxKeySize < keyAsString.Length)
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{
184-
Log.Info(
185-
"Computing a hashed key for too long key '{0}'. This may cause collisions resulting into additional cache misses.",
186-
key);
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// Hash it for respecting max key size. Collisions will be avoided by storing the actual key along
188185
// the object and comparing it on retrieval.
189-
using (var hasher = new SHA256Managed())
186+
var hash = Hasher.HashToString(keyAsString);
187+
if (hash.Length > _maxKeySize)
190188
{
191-
var bytes = Encoding.UTF8.GetBytes(keyAsString);
192-
var computedHash = Convert.ToBase64String(hasher.ComputeHash(bytes));
193-
if (computedHash.Length <= _maxKeySize)
194-
return computedHash;
195-
196189
if (!_hasWarnedOnHashLength)
197190
{
198191
// No lock for this field, some redundant logs will be less harm than locking.
@@ -201,14 +194,29 @@ private string GetCacheKey(object key)
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"Hash computed for too long keys are themselves too long. They will be truncated, further " +
202195
"increasing the risk of collision resulting into additional cache misses. Consider using a " +
203196
"cache supporting longer keys. Hash length: {0}; max key size: {1}",
204-
computedHash.Length, _maxKeySize);
197+
hash.Length, _maxKeySize);
205198
}
206199

207-
keyAsString = computedHash.Substring(0, _maxKeySize.Value);
200+
hash = hash.Substring(0, _maxKeySize.Value);
208201
}
202+
203+
var toLongKey = keyAsString;
204+
keyAsString = keyAsString.Substring(0, _maxKeySize.Value - hash.Length) + hash;
205+
Log.Info(
206+
"Computed the hashed key '{0}' for too long cache key '{1}' (object key '{2}'). This may cause" +
207+
"collisions resulting into additional cache misses.",
208+
keyAsString, toLongKey, key);
209209
}
210210

211-
return _keySanitizer != null ? _keySanitizer(keyAsString) : keyAsString;
211+
if (_keySanitizer != null)
212+
{
213+
Log.Debug("Sanitizing cache key '{0}'.", keyAsString);
214+
keyAsString = _keySanitizer(keyAsString);
215+
}
216+
217+
Log.Debug("Using cache key '{0}' for object key '{1}'.", keyAsString, key);
218+
219+
return keyAsString;
212220
}
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214222
/// <inheritdoc />

‎CoreDistributedCache/NHibernate.Caches.CoreDistributedCache/NHibernate.Caches.CoreDistributedCache.csproj

Lines changed: 5 additions & 5 deletions
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@@ -10,11 +10,8 @@ This provider is not bound to a specific implementation and require a cache fact
1010
<SignAssembly>True</SignAssembly>
1111
<AssemblyOriginatorKeyFile>..\..\NHibernate.Caches.snk</AssemblyOriginatorKeyFile>
1212
<GenerateDocumentationFile>true</GenerateDocumentationFile>
13-
<PackageReleaseNotes>* New feature
14-
* #47 - Add an option for appending hashcode to key
15-
16-
* Task
17-
* #46 - Update NHibernate to 5.1.0</PackageReleaseNotes>
13+
<PackageReleaseNotes>* Improvement
14+
* #52 - Cease using cryptographic hashes</PackageReleaseNotes>
1815
</PropertyGroup>
1916
<PropertyGroup Condition="'$(TargetFramework)' == 'net461'">
2017
<DefineConstants>NETFX;$(DefineConstants)</DefineConstants>
@@ -23,6 +20,9 @@ This provider is not bound to a specific implementation and require a cache fact
2320
<None Include="..\..\NHibernate.Caches.snk" Link="NHibernate.snk" />
2421
<None Include="..\default.build" Link="default.build" />
2522
</ItemGroup>
23+
<ItemGroup>
24+
<Compile Include="..\..\CommonInternals\Hasher.cs" />
25+
</ItemGroup>
2626
<ItemGroup>
2727
<PackageReference Include="Microsoft.Extensions.Caching.Abstractions" Version="2.0.0" />
2828
<PackageReference Include="NHibernate" Version="5.1.0" />

‎EnyimMemcached/NHibernate.Caches.EnyimMemcached/Async/MemCacheClient.cs

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@@ -11,11 +11,10 @@
1111
using System;
1212
using System.Collections;
1313
using System.Collections.Generic;
14-
using System.Security.Cryptography;
15-
using System.Text;
1614
using Enyim.Caching;
1715
using Enyim.Caching.Memcached;
1816
using NHibernate.Cache;
17+
using NHibernate.Caches.Util;
1918
using Environment = NHibernate.Cfg.Environment;
2019

2120
namespace NHibernate.Caches.EnyimMemcached

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