呼叫 Web API 的桌面應用程式:使用使用者名稱和密碼取得令牌
在您的傳統型應用程式中,您可以使用使用者名稱和密碼流程,也稱為資源擁有者密碼認證(ROPC),以無訊息方式取得令牌。
警告
不建議使用使用者名稱和密碼流程,因為應用程式會直接要求使用者輸入其密碼,這是不安全的模式。 如需 ROPC 流程所構成風險和挑戰的詳細資訊,請參閱 「密碼日益嚴重的問題解決方案為何?」。
此外,藉由使用使用者名稱和密碼,開發人員會放棄許多專案,包括:
- 新式身分識別的核心原則 - 密碼可能會遭到網路釣魚和重新執行,因為可以攔截共享密碼。
- 多重要素驗證 (MFA) - 使用者無法登入,因為沒有任何互動。
- 單一登錄 (SSO) 功能。
使用者名稱和密碼流程也有下列條件約束:
- 用戶名稱和密碼流程與條件式存取和多重要素驗證不相容。 如果您的應用程式在系統管理員需要多重要素驗證的 Microsoft Entra 租使用者中執行,就像大部分組織一樣,您就無法使用此流程。
- 它僅適用於公司與學校帳戶,不適用於個人 Microsoft 帳戶。
- 此流程可在 .NET 桌面和 .NET 上使用,但不適用於UWP。
在某些情況下,使用使用者名稱和密碼很有用,例如DevOps案例。 不過,如果您想要在提供自己的UI的互動式案例中使用使用者名稱和密碼,請考慮將其移開。
在 Windows 上以無訊息方式取得令牌的慣用流程是使用 Windows 驗證 訊息代理程式。 或者,開發人員也可以在 裝置上使用裝置程式代碼流程 ,而不需要存取網頁瀏覽器。
如果您要建置使用資源擁有者密碼認證 (ROPC) 流程登入使用者的電腦應用程式,請參閱 如何使用 Azure AD B2C 登入具有社交身分識別的使用者
使用 ROPC 流程
IPublicClientApplication
包含方法 AcquireTokenByUsernamePassword
。
下列範例提供簡化的案例。
static async Task GetATokenForGraph()
{
string authority = "https://login.microsoftonline.com/contoso.com";
string[] scopes = new string[] { "user.read" };
IPublicClientApplication app;
app = PublicClientApplicationBuilder.Create(clientId)
.WithAuthority(authority)
.Build();
var accounts = await app.GetAccountsAsync();
AuthenticationResult result = null;
if (accounts.Any())
{
result = await app.AcquireTokenSilent(scopes, accounts.FirstOrDefault())
.ExecuteAsync();
}
else
{
try
{
var securePassword = new SecureString();
foreach (char c in "dummy") // you should fetch the password
securePassword.AppendChar(c); // keystroke by keystroke
result = await app.AcquireTokenByUsernamePassword(scopes,
"joe@contoso.com",
securePassword)
.ExecuteAsync();
}
catch(MsalException)
{
// See details below
}
}
Console.WriteLine(result.Account.Username);
}
下列範例會呈現最新的案例,並說明您可以取得的例外狀況種類及其風險降低。
static async Task GetATokenForGraph()
{
string authority = "https://login.microsoftonline.com/contoso.com";
string[] scopes = new string[] { "user.read" };
IPublicClientApplication app;
app = PublicClientApplicationBuilder.Create(clientId)
.WithAuthority(authority)
.Build();
var accounts = await app.GetAccountsAsync();
AuthenticationResult result = null;
if (accounts.Any())
{
result = await app.AcquireTokenSilent(scopes, accounts.FirstOrDefault())
.ExecuteAsync();
}
else
{
try
{
var securePassword = new SecureString();
foreach (char c in "dummy") // you should fetch the password keystroke
securePassword.AppendChar(c); // by keystroke
result = await app.AcquireTokenByUsernamePassword(scopes,
"joe@contoso.com",
securePassword)
.ExecuteAsync();
}
catch (MsalUiRequiredException ex) when (ex.Message.Contains("AADSTS65001"))
{
// Here are the kind of error messages you could have, and possible mitigations
// ------------------------------------------------------------------------
// MsalUiRequiredException: AADSTS65001: The user or administrator has not consented to use the application
// with ID '{appId}' named '{appName}'. Send an interactive authorization request for this user and resource.
// Mitigation: you need to get user consent first. This can be done either statically (through the portal),
/// or dynamically (but this requires an interaction with Azure AD, which is not possible with
// the username/password flow)
// Statically: in the portal by doing the following in the "API permissions" tab of the application registration:
// 1. Click "Add a permission" and add all the delegated permissions corresponding to the scopes you want (for instance
// User.Read and User.ReadBasic.All)
// 2. Click "Grant/revoke admin consent for <tenant>") and click "yes".
// Dynamically, if you are not using .NET (which does not have any Web UI) by
// calling (once only) AcquireTokenInteractive.
// remember that Username/password is for public client applications that is desktop/mobile applications.
// If you are using .NET or don't want to call AcquireTokenInteractive, you might want to:
// - use device code flow (See https://aka.ms/msal-net-device-code-flow)
// - or suggest the user to navigate to a URL to consent: https://login.microsoftonline.com/common/oauth2/v2.0/authorize?client_id={clientId}&response_type=code&scope=user.read
// ------------------------------------------------------------------------
// ------------------------------------------------------------------------
// ErrorCode: invalid_grant
// SubError: basic_action
// MsalUiRequiredException: AADSTS50079: The user is required to use multi-factor authentication.
// The tenant admin for your organization has chosen to oblige users to perform multi-factor authentication.
// Mitigation: none for this flow
// Your application cannot use the Username/Password grant.
// Like in the previous case, you might want to use an interactive flow (AcquireTokenInteractive()),
// or Device Code Flow instead.
// Note this is one of the reason why using username/password is not recommended;
// ------------------------------------------------------------------------
// ------------------------------------------------------------------------
// ex.ErrorCode: invalid_grant
// subError: null
// Message = "AADSTS70002: Error validating credentials.
// AADSTS50126: Invalid username or password
// In the case of a managed user (user from an Azure AD tenant opposed to a
// federated user, which would be owned
// in another IdP through ADFS), the user has entered the wrong password
// Mitigation: ask the user to re-enter the password
// ------------------------------------------------------------------------
// ------------------------------------------------------------------------
// ex.ErrorCode: invalid_grant
// subError: null
// MsalServiceException: ADSTS50034: To sign into this application the account must be added to
// the {domainName} directory.
// or The user account does not exist in the {domainName} directory. To sign into this application,
// the account must be added to the directory.
// The user was not found in the directory
// Explanation: wrong username
// Mitigation: ask the user to re-enter the username.
// ------------------------------------------------------------------------
}
catch (MsalServiceException ex) when (ex.ErrorCode == "invalid_request")
{
// ------------------------------------------------------------------------
// AADSTS90010: The grant type is not supported over the /common or /consumers endpoints.
// Please use the /organizations or tenant-specific endpoint.
// you used common.
// Mitigation: as explained in the message from Azure AD, the authority you use in the application needs
// to be tenanted or otherwise "organizations". change the
// "Tenant": property in the appsettings.json to be a GUID (tenant Id), or domain name (contoso.com)
// if such a domain is registered with your tenant
// or "organizations", if you want this application to sign-in users in any Work and School accounts.
// ------------------------------------------------------------------------
}
catch (MsalServiceException ex) when (ex.ErrorCode == "unauthorized_client")
{
// ------------------------------------------------------------------------
// AADSTS700016: Application with identifier '{clientId}' was not found in the directory '{domain}'.
// This can happen if the application has not been installed by the administrator of the tenant or consented
// to by any user in the tenant.
// You may have sent your authentication request to the wrong tenant
// Cause: The clientId in the appsettings.json might be wrong
// Mitigation: check the clientId and the app registration
// ------------------------------------------------------------------------
}
catch (MsalServiceException ex) when (ex.ErrorCode == "invalid_client")
{
// ------------------------------------------------------------------------
// AADSTS70002: The request body must contain the following parameter: 'client_secret or client_assertion'.
// Explanation: this can happen if your application was not registered as a public client application in Azure AD
// Mitigation: in the Azure portal, edit the manifest for your application and set the `allowPublicClient` to `true`
// ------------------------------------------------------------------------
}
catch (MsalServiceException)
{
throw;
}
catch (MsalClientException ex) when (ex.ErrorCode == "unknown_user_type")
{
// Message = "Unsupported User Type 'Unknown'. Please see https://aka.ms/msal-net-up"
// The user is not recognized as a managed user, or a federated user. Azure AD was not
// able to identify the IdP that needs to process the user
throw new ArgumentException("U/P: Wrong username", ex);
}
catch (MsalClientException ex) when (ex.ErrorCode == "user_realm_discovery_failed")
{
// The user is not recognized as a managed user, or a federated user. Azure AD was not
// able to identify the IdP that needs to process the user. That's for instance the case
// if you use a phone number
throw new ArgumentException("U/P: Wrong username", ex);
}
catch (MsalClientException ex) when (ex.ErrorCode == "unknown_user")
{
// the username was probably empty
// ex.Message = "Could not identify the user logged into the OS. See https://aka.ms/msal-net-iwa for details."
throw new ArgumentException("U/P: Wrong username", ex);
}
catch (MsalClientException ex) when (ex.ErrorCode == "parsing_wstrust_response_failed")
{
// ------------------------------------------------------------------------
// In the case of a Federated user (that is owned by a federated IdP, as opposed to a managed user owned in an Azure AD tenant)
// ID3242: The security token could not be authenticated or authorized.
// The user does not exist or has entered the wrong password
// ------------------------------------------------------------------------
}
}
Console.WriteLine(result.Account.Username);
}
如需可套用至 AcquireTokenByUsernamePassword
之所有修飾詞的詳細資訊,請參閱 AcquireTokenByUsernamePasswordParameterBuilder。
下一步
請移至此案例中的下一篇文章, 從傳統型應用程式呼叫Web API。