Java Auth x EWS

Docs and code samples for Java Auth

EWS API Example (GitHub)

API Permission for this example

This old example is using the "basic auth" method

...which needs to be replaced with the code snippets from this document by getting a token first

// Using Microsoft.Identity.Client 4.22.0

// Configure the MSAL client to get tokens
var pcaOptions = new PublicClientApplicationOptions
{
    ClientId = ConfigurationManager.AppSettings["appId"],
    TenantId = ConfigurationManager.AppSettings["tenantId"]
};

var pca = PublicClientApplicationBuilder
    .CreateWithApplicationOptions(pcaOptions).Build();

// The permission scope required for EWS access
var ewsScopes = new string[] { "https://outlook.office365.com/EWS.AccessAsUser.All" };

// Make the interactive token request
var authResult = await pca.AcquireTokenInteractive(ewsScopes).ExecuteAsync();

...then pass the token to the ewsclient

// Configure the ExchangeService with the access token
var ewsClient = new ExchangeService();
ewsClient.Url = new Uri("https://outlook.office365.com/EWS/Exchange.asmx");
ewsClient.Credentials = new OAuthCredentials(authResult.AccessToken);

The example above is using the "Interactive" method for auth; if we need to use the "Non-Interactive" method, we need to use another method to get the token, like the guide here.

private static IAuthenticationResult acquireTokenUsernamePassword() throws Exception {

    // Load token cache from file and initialize token cache aspect. The token cache will have
    // dummy data, so the acquireTokenSilently call will fail.
    TokenCacheAspect tokenCacheAspect = new TokenCacheAspect("sample_cache.json");

    PublicClientApplication pca = PublicClientApplication.builder(CLIENT_ID)
            .authority(AUTHORITY)
            .setTokenCacheAccessAspect(tokenCacheAspect)
            .build();

    Set<IAccount> accountsInCache = pca.getAccounts().join();
    // Take first account in the cache. In a production application, you would filter
    // accountsInCache to get the right account for the user authenticating.
    IAccount account = accountsInCache.iterator().next();

    IAuthenticationResult result;
    try {
        SilentParameters silentParameters =
                SilentParameters
                        .builder(SCOPE, account)
                        .build();
        // try to acquire token silently. This call will fail since the token cache
        // does not have any data for the user you are trying to acquire a token for
        result = pca.acquireTokenSilently(silentParameters).join();
    } catch (Exception ex) {
        if (ex.getCause() instanceof MsalException) {

            UserNamePasswordParameters parameters =
                    UserNamePasswordParameters
                            .builder(SCOPE, USER_NAME, USER_PASSWORD.toCharArray())
                            .build();
            // Try to acquire a token via username/password. If successful, you should see
            // the token and account information printed out to console
            result = pca.acquireToken(parameters).join();
        } else {
            // Handle other exceptions accordingly
            throw ex;
        }
    }
    return result;
}

More examples can be found here.

Sample codes from Microsoft below

private static IAuthenticationResult acquireTokenUsernamePassword(PublicClientApplication pca,
        Set<String> scope,
        IAccount account,
        String username,
        String password) throws Exception {
    IAuthenticationResult result;
    try {
        SilentParameters silentParameters =
                SilentParameters
                        .builder(scope)
                        .account(account)
                        .build();
        // Try to acquire token silently. This will fail on the first acquireTokenUsernamePassword() call
        // because the token cache does not have any data for the user you are trying to acquire a token for
        result = pca.acquireTokenSilently(silentParameters).join();
        System.out.println("==acquireTokenSilently call succeeded");
    } catch (Exception ex) {
        if (ex.getCause() instanceof MsalException) {
            System.out.println("==acquireTokenSilently call failed: " + ex.getCause());
            UserNamePasswordParameters parameters =
                    UserNamePasswordParameters
                            .builder(scope, username, password.toCharArray())
                            .build();
            // Try to acquire a token via username/password. If successful, you should see
            // the token and account information printed out to console
            result = pca.acquireToken(parameters).join();
            System.out.println("==username/password flow succeeded");
        } else {
            // Handle other exceptions accordingly
            throw ex;
        }
    }
    return result;
}

public static String getAccessToken() throws Exception {
    Set<String> scope = new HashSet<String>();
    scope.add("https://outlook.office365.com/.default");
    String username = "[email protected]";
    String password = "userPass";
    String clientId = "xxxxxb-f4be-4e2e-95dd-7aa4f5dxxxxx";
    String tenantId = "xxxxx65f-f7e3-4bc3-841f-13b29xxxxx";
    String authority =
            "https://login.microsoftonline.com/" + tenantId + "/oauth2/v2.0/token";
    PublicClientApplication pca = PublicClientApplication.builder(clientId)
            .authority(authority)
            .build();

    //Get list of accounts from the application's token cache, and search them for the configured username
    //getAccounts() will be empty on this first call, as accounts are added to the cache when acquiring a token
    Set<IAccount> accountsInCache = pca.getAccounts().join();
    IAccount account = getAccountByUsername(accountsInCache, username);

    //Attempt to acquire token when user's account is not in the application's token cache
    IAuthenticationResult result = acquireTokenUsernamePassword(pca, scope, account, username, password);
    System.out.println("Account username: " + result.account().username());
    System.out.println("Access token:     " + result.accessToken());
    System.out.println("Id token:         " + result.idToken());
    System.out.println();

    accountsInCache = pca.getAccounts().join();
    account = getAccountByUsername(accountsInCache, username);

    //Attempt to acquire token again, now that the user's account and a token are in the application's token cache
    result = acquireTokenUsernamePassword(pca, scope, account, username, password);
    System.out.println("Account username: " + result.account().username());
    System.out.println("Access token:     " + result.accessToken());
    System.out.println("Id token:         " + result.idToken());

    return "";
}

private static IAccount getAccountByUsername(final Set<IAccount> accountsInCache, final String username) {
    if (accountsInCache.isEmpty()) {
        System.out.println("==No accounts in cache");
    } else {
        System.out.println("==Accounts in cache: " + accountsInCache.size());
        for (IAccount account : accountsInCache) {
            if (account.username().equals(username)) {
                return account;
            }
        }
    }
    return null;
}

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;
import java.util.HashMap;
import java.util.Map;

/**
 * <p>
 * Azure resource owner password credential (ROPC) token provider
 * https://docs.microsoft.com/en-us/azure/active-directory/develop/v2-oauth-ropc
 * https://docs.microsoft.com/en-us/exchange/client-developer/exchange-web-services/how-to-authenticate-an-ews-application-by-using-oauth
 * https://portal.azure.com
 * https://developer.microsoft.com/en-us/graph/graph-explorer/#
 * token parser https://jwt.io
 * </p>
 */
class AzureROPCTokenProvider implements ITokenProvider {

    private static final String GRANT_TYPE = "password";

    private final String clientId;
    private final String clientSecret;
    private final String userName;
    private final String password;
    private final String tenant;
    private final String scope;

    private OAuthToken token;

    public AzureROPCTokenProvider(String tenant, String clientId, String clientSecret,
                                  String userName, String password, String[] scopeAr) {
        this.tenant = tenant;
        this.clientId = clientId;
        this.clientSecret = clientSecret;
        this.userName = userName;
        this.password = password;
        this.scope = joinToStr(scopeAr, " ");
    }

    public synchronized OAuthToken getAccessToken(boolean ignoreExistingToken) {
        if (this.token != null && !this.token.getExpired() && !ignoreExistingToken)
            return this.token;
        token = null;

        Map<String, String> tokenArgs = geToken();

        java.util.Calendar c = java.util.Calendar.getInstance();
        c.add(java.util.Calendar.SECOND, Integer.parseInt(tokenArgs.get("expires_in")));
        token = new OAuthToken(tokenArgs.get("access_token"), TokenType.AccessToken, c.getTime());
        return token;
    }

    public final OAuthToken getAccessToken() {
        return getAccessToken(false);
    }

    public void dispose() {
    }

    private String getEncodedParameters() {
        return "client_id=" + urlEncode(clientId) + "&scope=" + urlEncode(scope) + "&username=" + urlEncode(userName)
                + "&password=" + urlEncode(password) + "&grant_type="
                + urlEncode(GRANT_TYPE);
    }

    private String getUri() {
        if (tenant == null || tenant.trim().isEmpty())
            return "https://login.microsoftonline.com/common/oauth2/v2.0/token";
        else
            return "https://login.microsoftonline.com/" + tenant + "/oauth2/v2.0/token";
    }

    private Map<String, String> geToken() {
        try {
            HttpURLConnection connection = (HttpURLConnection) new URL(getUri()).openConnection();
            connection.setRequestMethod("POST");

            byte[] requestData = getEncodedParameters().getBytes(StandardCharsets.UTF_8);

            connection.setUseCaches(false);
            connection.setDoInput(true);
            connection.setDoOutput(true);
            connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            connection.setRequestProperty("Content-Length", "" + requestData.length);

            final OutputStream st = connection.getOutputStream();
            try {
                st.write(requestData, 0, requestData.length);
            } finally {
                st.flush();
                st.close();
            }

            connection.connect();

            if (connection.getResponseCode() >= HttpURLConnection.HTTP_BAD_REQUEST) {
                throw new IllegalAccessError("Operation failed: " + connection.getResponseCode() + "/" +
                        connection.getResponseMessage() + "\r\nDetails:\r\n{2}"
                        + readInputStream(connection.getErrorStream()));
            }

            String responseText = readInputStream(connection.getInputStream());

            Map<String, String> result = new HashMap<>();
            String[] fromJsonToKeyValue = responseText.replace("{", "").replace("}", "")
                    .replace("\"", "").replace("\r", "")
                    .replace("\n", "").split(",");
            for (String keyValue : fromJsonToKeyValue) {
                String[] pair = keyValue.split(":");
                String name = pair[0].trim().toLowerCase();
                String value = urlDecode(pair[1].trim());
                result.put(name, value);
            }

            return result;
        } catch (IOException e) {
            throw new IllegalAccessError(e.getMessage());
        }
    }

    static String urlEncode(String value) {
        try {
            return URLEncoder.encode(value, StandardCharsets.UTF_8.toString());
        } catch (UnsupportedEncodingException e) {
            throw new IllegalAccessError(e.getMessage());
        }
    }

    static String urlDecode(String value) {
        try {
            return URLDecoder.decode(value, StandardCharsets.UTF_8.toString());
        } catch (UnsupportedEncodingException e) {
            throw new IllegalAccessError(e.getMessage());
        }
    }

    static String readInputStream(InputStream is) {
        if (is == null)
            return "";

        BufferedReader reader = new BufferedReader(new InputStreamReader(is));
        StringBuilder result = new StringBuilder();
        String line;
        try {
            while ((line = reader.readLine()) != null) {
                result.append(line);
            }
        } catch (IOException e) {
            // ignore
        }
        return result.toString();
    }

    static String joinToStr(String[] arr, String sep) {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < arr.length; i++) {
            if (i > 0)
                sb.append(sep);
            sb.append(arr[i]);
        }
        return sb.toString();
    }
}