#region Copyright notice and license
// Copyright 2015, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#endregion
using System;
using System.Collections.Generic;
using System.IO;
using System.Security.Cryptography;
using Google.Apis.Auth.OAuth2;
using Mono.Security.Cryptography;
using Newtonsoft.Json.Linq;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Security;
namespace Grpc.Auth
{
// TODO(jtattermusch): Remove this class once possible.
///
/// A temporary placeholder for Google credential from
/// Google Auth library for .NET. It emulates the usage pattern
/// for Usable auth.
///
public class GoogleCredential
{
private const string GoogleApplicationCredentialsEnvName = "GOOGLE_APPLICATION_CREDENTIALS";
private const string ClientEmailFieldName = "client_email";
private const string PrivateKeyFieldName = "private_key";
private ServiceCredential credential;
private GoogleCredential(ServiceCredential credential)
{
this.credential = credential;
}
public static GoogleCredential GetApplicationDefault()
{
return new GoogleCredential(null);
}
public bool IsCreateScopedRequired
{
get
{
return true;
}
}
public GoogleCredential CreateScoped(IEnumerable scopes)
{
var credsPath = Environment.GetEnvironmentVariable(GoogleApplicationCredentialsEnvName);
if (credsPath == null)
{
// Default to ComputeCredentials if path to JSON key is not set.
// ComputeCredential is not scoped actually, but for our use case it's
// fine to treat is as such.
return new GoogleCredential(new ComputeCredential(new ComputeCredential.Initializer()));
}
JObject o1 = JObject.Parse(File.ReadAllText(credsPath));
string clientEmail = o1.GetValue(ClientEmailFieldName).Value();
string privateKeyString = o1.GetValue(PrivateKeyFieldName).Value();
var privateKey = ParsePrivateKeyFromString(privateKeyString);
var serviceCredential = new ServiceAccountCredential(
new ServiceAccountCredential.Initializer(clientEmail)
{
Scopes = scopes,
Key = privateKey
});
return new GoogleCredential(serviceCredential);
}
internal ServiceCredential InternalCredential
{
get
{
return credential;
}
}
private RSACryptoServiceProvider ParsePrivateKeyFromString(string base64PrivateKey)
{
// TODO(jtattermusch): temporary code to create RSACryptoServiceProvider.
base64PrivateKey = base64PrivateKey.Replace("-----BEGIN PRIVATE KEY-----", "").Replace("\n", "").Replace("-----END PRIVATE KEY-----", "");
PKCS8.PrivateKeyInfo PKI = new PKCS8.PrivateKeyInfo(Convert.FromBase64String(base64PrivateKey));
RsaPrivateCrtKeyParameters key = (RsaPrivateCrtKeyParameters)PrivateKeyFactory.CreateKey(PKI.GetBytes());
RSAParameters rsaParameters = DotNetUtilities.ToRSAParameters(key);
RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
rsa.ImportParameters(rsaParameters);
return rsa;
}
}
}