Add a distinct MsalJsonParsingException for JSON parsing failures

Author: Avery-Dunn

msal4j-sdk/src/main/java/com/microsoft/aad/msal4j/AbstractManagedIdentitySource.java

@@ -93,7 +93,12 @@ public ManagedIdentityResponse handleResponse(
 
     protected ManagedIdentityResponse getSuccessfulResponse(IHttpResponse response) {
 
-        ManagedIdentityResponse managedIdentityResponse = JsonHelper.convertJsonStringToJsonSerializableObject(response.body(), ManagedIdentityResponse::fromJson);
+        ManagedIdentityResponse managedIdentityResponse;
+        try {
+            managedIdentityResponse = JsonHelper.convertJsonStringToJsonSerializableObject(response.body(), ManagedIdentityResponse::fromJson);
+        } catch (MsalJsonParsingException e) {
+            throw new MsalJsonParsingException(String.format(MsalErrorMessage.MANAGED_IDENTITY_RESPONSE_SUCCESSFUL_PARSE_FAILURE, e.getMessage()), MsalError.MANAGED_IDENTITY_RESPONSE_PARSE_FAILURE, managedIdentitySourceType);
+        }
 
         if (managedIdentityResponse == null || managedIdentityResponse.getAccessToken() == null
                 || managedIdentityResponse.getAccessToken().isEmpty() || managedIdentityResponse.getExpiresOn() == null
@@ -105,8 +110,13 @@ protected ManagedIdentityResponse getSuccessfulResponse(IHttpResponse response)
     }
 
     protected String getMessageFromErrorResponse(IHttpResponse response) {
-        ManagedIdentityErrorResponse managedIdentityErrorResponse =
-                JsonHelper.convertJsonToObject(response.body(), ManagedIdentityErrorResponse.class);
+
+        ManagedIdentityErrorResponse managedIdentityErrorResponse;
+        try {
+            managedIdentityErrorResponse = JsonHelper.convertJsonToObject(response.body(), ManagedIdentityErrorResponse.class);
+        } catch (MsalJsonParsingException e) {
+            throw new MsalJsonParsingException(String.format(MsalErrorMessage.MANAGED_IDENTITY_RESPONSE_FAILED_PARSE_FAILURE, e.getMessage()), MsalError.MANAGED_IDENTITY_RESPONSE_PARSE_FAILURE, managedIdentitySourceType);
+        }
 
         if (managedIdentityErrorResponse == null) {
             return MANAGED_IDENTITY_NO_RESPONSE_RECEIVED;

msal4j-sdk/src/main/java/com/microsoft/aad/msal4j/JsonHelper.java

@@ -35,19 +35,17 @@ private JsonHelper() {
     static <T> T convertJsonToObject(final String json, final Class<T> tClass) {
         try {
             return mapper.readValue(json, tClass);
-        } catch (IOException e) {
-            throw new MsalClientException(e);
+        } catch (Exception e) {
+            throw new MsalJsonParsingException(e.getMessage(), AuthenticationErrorCode.INVALID_JSON);
         }
     }
 
     //This method is used to convert a JSON string to an object which implements the JsonSerializable interface from com.azure.json
     static <T extends JsonSerializable<T>> T convertJsonStringToJsonSerializableObject(String jsonResponse, ReadValueCallback<JsonReader, T> readFunction) {
         try (JsonReader jsonReader = JsonProviders.createReader(jsonResponse)) {
             return readFunction.read(jsonReader);
-        } catch (IOException e) {
-            throw new MsalClientException(e.getMessage(), AuthenticationErrorCode.INVALID_JSON);
         } catch (Exception e) {
-            throw new MsalClientException("Error parsing JSON response: " + e.getMessage(), AuthenticationErrorCode.INVALID_JSON);
+            throw new MsalJsonParsingException(e.getMessage(), AuthenticationErrorCode.INVALID_JSON);
         }
     }
 

msal4j-sdk/src/main/java/com/microsoft/aad/msal4j/MsalError.java

@@ -34,4 +34,6 @@ public class MsalError {
     public static final String MANAGED_IDENTITY_UNREACHABLE_NETWORK = "managed_identity_unreachable_network";
 
     public static final String MANAGED_IDENTITY_FILE_READ_ERROR = "managed_identity_file_read_error";
+
+    public static final String MANAGED_IDENTITY_RESPONSE_PARSE_FAILURE = "managed_identity_response_parse_failure";
 }

msal4j-sdk/src/main/java/com/microsoft/aad/msal4j/MsalErrorMessage.java

@@ -26,4 +26,8 @@ class MsalErrorMessage {
     public static final String IDENTITY_UNAVAILABLE_ERROR = "[Managed Identity] Authentication unavailable. The requested identity has not been assigned to this resource.";
 
     public static final String GATEWAY_ERROR = "[Managed Identity] Authentication unavailable. The request failed due to a gateway error.";
+
+    public static final String MANAGED_IDENTITY_RESPONSE_SUCCESSFUL_PARSE_FAILURE = "[Managed Identity] MSI returned 200 OK, but the response could not be parsed: %s";
+
+    public static final String MANAGED_IDENTITY_RESPONSE_FAILED_PARSE_FAILURE = "[Managed Identity] MSI did not return 200 OK, and the response could not be parsed: %s";
 }

msal4j-sdk/src/main/java/com/microsoft/aad/msal4j/MsalJsonParsingException.java

@@ -0,0 +1,34 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+package com.microsoft.aad.msal4j;
+
+/**
+ * This exception class informs developers that a response contained invalid JSON or otherwise could not be parsed
+ */
+public class MsalJsonParsingException extends MsalServiceException {
+
+    /**
+     * Initializes a new instance of the exception class with a specified error message
+     *
+     * @param message the error message that explains the reason for the exception
+     * @param error a simplified error code from {@link AuthenticationErrorCode} and used for references in documentation
+     */
+    MsalJsonParsingException(final String message, final String error) {
+        super(message, error);
+    }
+
+    /**
+     * Initializes a new instance of the exception class, with extra properties for a Managed Identity error
+     *
+     * @param message the error message that explains the reason for the exception
+     * @param error a simplified error code
+     * @param managedIdentitySource the Managed Identity service
+     */
+    MsalJsonParsingException(
+            final String message, final String error,
+            ManagedIdentitySourceType managedIdentitySource) {
+        super(message, error, managedIdentitySource);
+    }
+
+}

msal4j-sdk/src/test/java/com/microsoft/aad/msal4j/ManagedIdentityTests.java

@@ -49,6 +49,10 @@ private String getSuccessfulResponse(String resource) {
                 "\"Bearer\",\"client_id\":\"client_id\"}";
     }
 
+    private String getSuccessfulResponseWithInvalidJson() {
+        return "missing starting bracket \"access_token\":\"accesstoken\",\"token_type\":" + "\"Bearer\",\"client_id\":\"a bunch of problems}";
+    }
+
     private String getMsiErrorResponse() {
         return "{\"statusCode\":\"500\",\"message\":\"An unexpected error occured while fetching the AAD Token.\",\"correlationId\":\"7d0c9763-ff1d-4842-a3f3-6d49e64f4513\"}";
     }
@@ -203,6 +207,40 @@ void managedIdentityTest_SystemAssigned_SuccessfulResponse(ManagedIdentitySource
         verify(httpClientMock, times(1)).send(any());
     }
 
+    @ParameterizedTest
+    @MethodSource("com.microsoft.aad.msal4j.ManagedIdentityTestDataProvider#createData")
+    void managedIdentityTest_SuccessfulResponse_WithInvalidJson(ManagedIdentitySourceType source, String endpoint, String resource) throws Exception {
+        IEnvironmentVariables environmentVariables = new EnvironmentVariablesHelper(source, endpoint);
+        ManagedIdentityApplication.setEnvironmentVariables(environmentVariables);
+        DefaultHttpClient httpClientMock = mock(DefaultHttpClient.class);
+        if (source == SERVICE_FABRIC) {
+            ServiceFabricManagedIdentitySource.setHttpClient(httpClientMock);
+        }
+
+        when(httpClientMock.send(expectedRequest(source, resource))).thenReturn(expectedResponse(200, getSuccessfulResponseWithInvalidJson()));
+
+        miApp = ManagedIdentityApplication
+                .builder(ManagedIdentityId.systemAssigned())
+                .httpClient(httpClientMock)
+                .build();
+
+        // Clear caching to avoid cross test pollution.
+        miApp.tokenCache().accessTokens.clear();
+
+        try {
+            miApp.acquireTokenForManagedIdentity(
+                    ManagedIdentityParameters.builder(resource)
+                            .build()).get();
+            fail("MsalServiceException is expected but not thrown.");
+        } catch (ExecutionException exception) {
+            assert(exception.getCause() instanceof MsalJsonParsingException);
+
+            MsalJsonParsingException miException = (MsalJsonParsingException) exception.getCause();
+            assertEquals(source.name(), miException.managedIdentitySource());
+            assertEquals(MANAGED_IDENTITY_RESPONSE_PARSE_FAILURE, miException.errorCode());
+        }
+    }
+
     @ParameterizedTest
     @MethodSource("com.microsoft.aad.msal4j.ManagedIdentityTestDataProvider#createDataUserAssigned")
     void managedIdentityTest_UserAssigned_SuccessfulResponse(ManagedIdentitySourceType source, String endpoint, ManagedIdentityId id) throws Exception {
@@ -454,7 +492,7 @@ void managedIdentity_RequestFailed_NoPayload(ManagedIdentitySourceType source, S
 
             MsalServiceException miException = (MsalServiceException) exception.getCause();
             assertEquals(source.name(), miException.managedIdentitySource());
-            assertEquals(AuthenticationErrorCode.MANAGED_IDENTITY_REQUEST_FAILED, miException.errorCode());
+            assertEquals(MANAGED_IDENTITY_RESPONSE_PARSE_FAILURE, miException.errorCode());
             return;
         }