OaepSHA1 -> OaepSHA256

src/Agent.Listener/Configuration.Windows/RSAEncryptedFileKeyManager.cs

@@ -132,12 +132,12 @@ public void DeleteKey()
             }
         }
 
-        public RSA GetKey()
+        public RSA GetKey(bool useLegacyRsaImpl)
         {
-            return GetKeyFromFile();
+            return GetKeyFromFile(useLegacyRsaImpl);
         }
 
-        private RSA GetKeyFromNamedContainer()
+        private RSA GetKeyFromNamedContainer(bool useLegacyRsaImpl)
         {
             if (!File.Exists(_keyFile))
             {
@@ -151,7 +151,7 @@ private RSA GetKeyFromNamedContainer()
             if (string.IsNullOrEmpty(result.containerName))
             {
                 // we should not get here.  GetKeyFromNamedContainer is only called from GetKeyFromFile when result.containerName is not empty
-                return GetKeyFromFile();
+                return GetKeyFromFile(useLegacyRsaImpl);
             }
 
             if (result.useCng)
@@ -170,13 +170,24 @@ private RSA GetKeyFromNamedContainer()
                 Trace.Info("Using RSACryptoServiceProvider");
                 CspParameters Params = new CspParameters();
                 Params.KeyContainerName = result.containerName;
-                Params.Flags |= CspProviderFlags.UseNonExportableKey | CspProviderFlags.UseMachineKeyStore;
-                var rsa = new RSACryptoServiceProvider(Params);
-                return rsa;
+                if (useLegacyRsaImpl)
+                {
+                    Params.Flags |= CspProviderFlags.UseNonExportableKey | CspProviderFlags.UseMachineKeyStore;
+                    var rsa = new RSACryptoServiceProvider(Params);
+                    return rsa;
+                }
+                else
+                {
+                    Params.Flags |= CspProviderFlags.UseMachineKeyStore;
+                    using (var csp = new RSACryptoServiceProvider(Params))
+                    {
+                        return RSA.Create(csp.ExportParameters(includePrivateParameters: true));
+                    }
+                }
             }
         }
 
-        private RSA GetKeyFromFile()
+        private RSA GetKeyFromFile(bool useLegacyRsaImpl)
         {
             if (!File.Exists(_keyFile))
             {
@@ -190,10 +201,10 @@ private RSA GetKeyFromFile()
             if(!string.IsNullOrEmpty(result.containerName))
             {
                 Trace.Info("Keyfile has ContainerName, reading from NamedContainer");
-                return GetKeyFromNamedContainer();
+                return GetKeyFromNamedContainer(useLegacyRsaImpl);
             }
 
-            var rsa = new RSACryptoServiceProvider();
+            var rsa = useLegacyRsaImpl ? new RSACryptoServiceProvider() : RSA.Create();
             rsa.ImportParameters(result.rsaParameters);
             return rsa;
         }

src/Agent.Listener/Configuration/IRSAKeyManager.cs

@@ -35,11 +35,12 @@ public interface IRSAKeyManager : IAgentService
         void DeleteKey();
 
         /// <summary>
-        /// Gets the <c>RSACryptoServiceProvider</c> instance currently stored by the key manager. 
+        /// Gets the <c>RSA</c> instance currently stored by the key manager. 
         /// </summary>
-        /// <returns>An <c>RSACryptoServiceProvider</c> instance representing the key for the agent</returns>
+        /// <param name="useLegacyRsaImpl">Use RSACryptoServiceProvider as the underlying implementation.</param>
+        /// <returns>An <c>RSA</c> implementation representing the key for the agent</returns>
         /// <exception cref="CryptographicException">No key exists in the store</exception>
-        RSA GetKey();
+        RSA GetKey(bool useLegacyRsaImpl);
     }
 
     public static class IRSAKeyManagerExtensions

src/Agent.Listener/Configuration/OAuthCredential.cs

@@ -42,7 +42,7 @@ public override VssCredentials GetVssCredentials(IHostContext context)
             // We expect the key to be in the machine store at this point. Configuration should have set all of
             // this up correctly so we can use the key to generate access tokens.
             var keyManager = context.GetService<IRSAKeyManager>();
-            var signingCredentials = VssSigningCredentials.Create(() => keyManager.GetKey());
+            var signingCredentials = VssSigningCredentials.Create(() => keyManager.GetKey(useLegacyRsaImpl: true)); // RSACryptoServiceProvider is fine for signatures
             var clientCredential = new VssOAuthJwtBearerClientCredential(clientId, authorizationUrl, signingCredentials);
             var agentCredential = new VssOAuthCredential(new Uri(oathEndpointUrl, UriKind.Absolute), VssOAuthGrant.ClientCredentials, clientCredential);
 

src/Agent.Listener/Configuration/RSAFileKeyManager.cs

@@ -70,7 +70,7 @@ public void DeleteKey()
             }
         }
 
-        public RSA GetKey()
+        public RSA GetKey(bool useLegacyRsaImpl)
         {
             if (!File.Exists(_keyFile))
             {
@@ -80,7 +80,7 @@ public RSA GetKey()
             Trace.Info("Loading RSA key parameters from file {0}", _keyFile);
 
             var parameters = IOUtil.LoadObject<RSAParametersSerializable>(_keyFile).RSAParameters;
-            var rsa = new RSACryptoServiceProvider();
+            var rsa = useLegacyRsaImpl ? new RSACryptoServiceProvider() : RSA.Create();
             rsa.ImportParameters(parameters);
             return rsa;
         }

src/Agent.Listener/MessageListener.cs

@@ -95,6 +95,7 @@ public async Task<Boolean> CreateSessionAsync(CancellationToken token)
                     await _agentServer.ConnectAsync(new Uri(serverUrl), creds);
                     Trace.Info("VssConnection created");
 
+                    taskAgentSession.AgentCanHandleOaepSHA256 = true;
                     _session = await _agentServer.CreateAgentSessionAsync(
                                                         _settings.PoolId,
                                                         taskAgentSession,
@@ -336,9 +337,10 @@ private ICryptoTransform GetMessageDecryptor(
             {
                 // The agent session encryption key uses the AES symmetric algorithm
                 var keyManager = HostContext.GetService<IRSAKeyManager>();
-                using (var rsa = keyManager.GetKey())
+                RSAEncryptionPadding rsaPadding = _session.EncryptionKey.EncryptionPadding == "OaepSHA256" ? RSAEncryptionPadding.OaepSHA256 : RSAEncryptionPadding.OaepSHA1;
+                using (var rsa = keyManager.GetKey(useLegacyRsaImpl: rsaPadding == RSAEncryptionPadding.OaepSHA1))
                 {
-                    return aes.CreateDecryptor(rsa.Decrypt(_session.EncryptionKey.Value, RSAEncryptionPadding.OaepSHA1), message.IV);
+                    return aes.CreateDecryptor(rsa.Decrypt(_session.EncryptionKey.Value, rsaPadding), message.IV);
                 }
             }
             else