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Added RestSharp encryption/decryption interceptor
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8 files changed

+567
-2
lines changed

8 files changed

+567
-2
lines changed

‎Mastercard.Developer.ClientEncryption.Core/Encryption/FieldLevelEncryption.cs‎

Lines changed: 2 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -345,7 +345,8 @@ private static string SanitizeJson(string json)
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{
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return json.Replace("\n", string.Empty)
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.Replace("\r", string.Empty)
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.Replace("\t", string.Empty);
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.Replace("\t", string.Empty)
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.Replace(Environment.NewLine, string.Empty);
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}
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private static JToken AsPrimitiveValue(string value)

‎Mastercard.Developer.ClientEncryption.Core/Encryption/FieldLevelEncryptionConfig.cs‎

Lines changed: 6 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -138,8 +138,13 @@ internal FieldLevelEncryptionConfig() {}
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public FieldValueEncoding ValueEncoding { get; internal set; }
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/// <summary>
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/// If the encryption parameters must be written to/read from HTTP headers.
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/// If the encryption parameters must be written to/read from HTTP payloads.
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/// </summary>
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public bool UseHttpPayloads() => !string.IsNullOrEmpty(EncryptedKeyFieldName) && !string.IsNullOrEmpty(IvFieldName);
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/// <summary>
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/// If the encryption parameters must be written to/read from HTTP headers.
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/// </summary>
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public bool UseHttpHeaders() => !string.IsNullOrEmpty(EncryptedKeyHeaderName) && !string.IsNullOrEmpty(IvHeaderName);
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}
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}

‎Mastercard.Developer.ClientEncryption.RestSharp/Interceptors/RestSharpFieldLevelEncryptionInterceptor.cs‎

Lines changed: 166 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,166 @@
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using System;
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using System.Linq;
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using System.Reflection;
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using Mastercard.Developer.ClientEncryption.Core.Encryption;
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using RestSharp.Portable;
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namespace Mastercard.Developer.ClientEncryption.RestSharp.Interceptors
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{
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/// <summary>
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/// A class for encrypting RestSharp requests and decrypting RestSharp responses.
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/// </summary>
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public class RestSharpFieldLevelEncryptionInterceptor
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{
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private readonly FieldLevelEncryptionConfig _config;
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public RestSharpFieldLevelEncryptionInterceptor(FieldLevelEncryptionConfig config)
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{
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_config = config;
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}
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/// <summary>
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/// Encrypt RestSharp request payloads.
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/// </summary>
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/// <param name="request">A RestSharp request object</param>
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public void InterceptRequest(IRestRequest request)
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{
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if (request == null) throw new ArgumentNullException(nameof(request));
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try
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{
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// Check request actually has a payload
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var bodyParam = request.Parameters.FirstOrDefault(param => param.Type == ParameterType.RequestBody);
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if (bodyParam == null)
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{
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// Nothing to encrypt
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return;
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}
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var payload = bodyParam.Value.ToString();
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if (string.IsNullOrEmpty(payload))
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{
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// Nothing to encrypt
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return;
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}
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// Encrypt fields & update headers
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string encryptedPayload;
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if (_config.UseHttpHeaders())
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{
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// Generate encryption params and add them as HTTP headers
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var parameters = FieldLevelEncryptionParams.Generate(_config);
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UpdateRequestHeader(request, _config.IvHeaderName, parameters.IvValue);
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UpdateRequestHeader(request, _config.EncryptedKeyHeaderName, parameters.EncryptedKeyValue);
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UpdateRequestHeader(request, _config.EncryptionCertificateFingerprintHeaderName, parameters.EncryptionCertificateFingerprintValue);
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UpdateRequestHeader(request, _config.EncryptionKeyFingerprintHeaderName, parameters.EncryptionKeyFingerprintValue);
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UpdateRequestHeader(request, _config.OaepPaddingDigestAlgorithmHeaderName, parameters.OaepPaddingDigestAlgorithmValue);
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encryptedPayload = FieldLevelEncryption.EncryptPayload(payload, _config, parameters);
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}
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else
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{
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// Encryption params will be stored in the payload
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encryptedPayload = FieldLevelEncryption.EncryptPayload(payload, _config);
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}
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// Update body and content length
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bodyParam.Value = encryptedPayload;
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UpdateRequestHeader(request, "Content-Length", encryptedPayload.Length);
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}
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catch (EncryptionException)
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{
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throw;
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}
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catch (Exception e)
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{
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throw new EncryptionException("Failed to intercept and encrypt request!", e);
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}
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}
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/// <summary>
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/// Decrypt RestSharp response payloads.
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/// </summary>
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/// <param name="response">A RestSharp response object</param>
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public void InterceptResponse(IRestResponse response)
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{
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if (response == null) throw new ArgumentNullException(nameof(response));
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try
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{
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// Read response payload
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var encryptedPayload = response.Content;
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if (string.IsNullOrEmpty(encryptedPayload))
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{
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// Nothing to decrypt
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return;
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}
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// Decrypt fields & update headers
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string decryptedPayload;
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if (_config.UseHttpHeaders())
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{
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// Read encryption params from HTTP headers and delete headers
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var ivValue = ReadAndRemoveHeader(response, _config.IvHeaderName);
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var encryptedKeyValue = ReadAndRemoveHeader(response, _config.EncryptedKeyHeaderName);
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var oaepPaddingDigestAlgorithmValue = ReadAndRemoveHeader(response, _config.OaepPaddingDigestAlgorithmHeaderName);
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ReadAndRemoveHeader(response, _config.EncryptionCertificateFingerprintHeaderName);
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ReadAndRemoveHeader(response, _config.EncryptionKeyFingerprintHeaderName);
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var parameters = new FieldLevelEncryptionParams(_config, ivValue, encryptedKeyValue, oaepPaddingDigestAlgorithmValue);
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decryptedPayload = FieldLevelEncryption.DecryptPayload(encryptedPayload, _config, parameters);
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}
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else
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{
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// Encryption params are stored in the payload
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decryptedPayload = FieldLevelEncryption.DecryptPayload(encryptedPayload, _config);
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}
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// Update body and content length
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var contentTypeInfo = response.GetType().GetTypeInfo().GetDeclaredField("_content");
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contentTypeInfo.SetValue(response, new Lazy<string>(() => decryptedPayload));
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UpdateResponseHeader(response, "Content-Length", decryptedPayload.Length.ToString());
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}
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catch (EncryptionException)
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{
122+
throw;
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}
124+
catch (Exception e)
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{
126+
throw new EncryptionException("Failed to intercept and decrypt response!", e);
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}
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}
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private static void UpdateRequestHeader(IRestRequest request, string name, object value)
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{
132+
if (string.IsNullOrEmpty(name))
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{
134+
// Do nothing
135+
return;
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}
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138+
request.AddOrUpdateHeader(name, value);
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}
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private static void UpdateResponseHeader(IRestResponse response, string name, string value)
142+
{
143+
if (string.IsNullOrEmpty(name))
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{
145+
// Do nothing
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return;
147+
}
148+
149+
response.Headers.Remove(name);
150+
response.Headers.Add(name, value);
151+
}
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private static string ReadAndRemoveHeader(IRestResponse response, string name)
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{
155+
if (string.IsNullOrEmpty(name) || !response.Headers.Contains(name))
156+
{
157+
// Do nothing
158+
return null;
159+
}
160+
161+
var value = response.Headers.GetValue(name);
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response.Headers.Remove(name);
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return value;
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}
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}
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}

‎Mastercard.Developer.ClientEncryption.RestSharp/Mastercard.Developer.ClientEncryption.RestSharp.csproj‎

Lines changed: 35 additions & 0 deletions
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<Project Sdk="Microsoft.NET.Sdk">
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<PropertyGroup>
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<TargetFramework>netstandard1.3</TargetFramework>
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<GeneratePackageOnBuild>true</GeneratePackageOnBuild>
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<Version>1.0.0</Version>
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<Product>Mastercard.Developer.ClientEncryption.RestSharp</Product>
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<Authors>Mastercard</Authors>
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<Company>Mastercard</Company>
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<PackageLicenseFile>LICENSE</PackageLicenseFile>
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<PackageProjectUrl>https://github.com/Mastercard/client-encryption-csharp</PackageProjectUrl>
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<PackageReleaseNotes>See: https://github.com/Mastercard/client-encryption-csharp/releases</PackageReleaseNotes>
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<RepositoryUrl>https://github.com/Mastercard/client-encryption-csharp</RepositoryUrl>
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<Description>Library for Mastercard API compliant payload encryption/decryption</Description>
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<!-- See: https://docs.microsoft.com/en-us/dotnet/standard/library-guidance/strong-naming -->
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<SignAssembly>true</SignAssembly>
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<AssemblyOriginatorKeyFile>../Identity.snk</AssemblyOriginatorKeyFile>
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<AssemblyVersion>1.0.0.0</AssemblyVersion> <!-- Frozen -->
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<FileVersion>1.0.0.0</FileVersion> <!-- Same version as the package version -->
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</PropertyGroup>
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<ItemGroup>
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<None Include="../LICENSE" Pack="true" PackagePath="" />
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<None Include="../README.md" Pack="true" PackagePath="" />
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</ItemGroup>
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<ItemGroup>
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<PackageReference Include="FubarCoder.RestSharp.Portable.Core" Version="4.0.6" /> <!-- Minimum version, inclusive -->
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</ItemGroup>
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<ItemGroup>
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<ProjectReference Include="..\Mastercard.Developer.ClientEncryption.Core\Mastercard.Developer.ClientEncryption.Core.csproj" />
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</ItemGroup>
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</Project>

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