# API authentication
---

All API requests need to be authenticated through the Authorization header. The Infobip API offers the following authentication methods:
  
- HTTP Basic authentication
- API keys
- IBSSO tokens
- OAuth 2.0

Select your preferred method to suit your current tech stack and security requirement level. Many of these methods are vulnerable to man-in-the-middle attacks, so it is recommended to combine them with other security mechanisms such as an encrypted connection or SSL.
  
Refer to the [Errors](https://www.infobip.com/docs/api-authentication#errors) section to troubleshoot potential issues, or alternatively reach out to the Infobip Support team for help.

## Basic
  
**Basic authentication** works by sending a username and password in every API request. Typically, this method is used in situations when the API key is not available. For example, API methods generating API keys could be authenticated with Basic.
  
Basic Auth is the least recommended method as it is still simple to decode encrypted credentials back to their original values. Refer to the [HTTP Authentication resource](https://developer.mozilla.org/en-US/docs/Web/HTTP/Authentication) to see how to restrict access to your server with Basic authentication.
  
Here are some key facts about this method:

- Built into HTTP protocol itself
- Credentials should be encoded in a Base64 format (for example, with the [RFC2045-MIME](https://www.ietf.org/rfc/rfc2045.txt) variant) and separated by a colon (:)
- Encoded credentials are added to the header after `Basic`

#### Example - HTTP client
  
When using any of the Infobip API [client libraries](https://github.com/infobip?q=infobip-api-*-client&type=&language=&sort=#org-profiles-repositories) you don't have to manually encode the credentials. You only need to specify the username and password when creating an instance of a client object.
  
```curl
curl -L -g -X GET 'https://{baseUrl}/sms/2/text/advanced' /
-H 'Authorization: Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ=='
```

```java
String auth = username + ":" + password;
String encoded = Base64.getEncoder().encodeToString(auth.getBytes("UTF-8"));
 
String messageText = "This is test message sent using OkHttpClient and Basic auth";
String jsonBody = String.format(
        "{\"messages\":[{\"from\":\"%s\",\"destinations\":[{\"to\":\"%s\"}],\"text\":\"%s\"}]}",
        SENDER, PHONE_NUMBER, messageText);
 
RequestBody requestBody = RequestBody.create(MediaType.parse("application/json; charset=utf-8"), jsonBody);
 
Request request = new Request.Builder()
        .url(BASE_URL + "/sms/2/text/advanced")
        .addHeader("Authorization", "Basic " + encoded)
        .addHeader("Content-Type", "application/json")
        .addHeader("Accept", "application/json")
        .post(requestBody)
        .build();
 
OkHttpClient httpClient = new OkHttpClient().newBuilder().build();
Response response = httpClient.newCall(request).execute();
System.out.println(response.body().string());
```

```csharp
string username = "USERNAME";
string password = "PASSWORD";
string concatenated = $"{username}:{password}";
string encoded = Convert.ToBase64String(System.Text.Encoding.UTF8.GetBytes(concatenated));
 
HttpClient client = new HttpClient();
client.BaseAddress = new Uri("BASE_URL");
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", encoded);
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
```

#### Example - API client library
  
When using any of the Infobip API [client libraries](https://github.com/infobip?q=infobip-api-*-client&type=&language=&sort=#org-profiles-repositories) you do not have to manually encode the credentials data like mentioned above. You only need to specify the username and password when creating an instance of a client object as shown in the example below.
  
```csharp
var configuration = new Configuration()
{
    BasePath = "BASE_URL",
    Username = "USERNAME",
    Password = "PASSWORD"
};
```

### API scopes on Basic Auth [#api-scopes-on-basic-auth-basic]

For information on API scopes associated with Basic Auth, refer to the dedicated [User roles and API scopes](https://www.infobip.com/docs/essentials/api-essentials/api-authorization#user-roles-and-api-scopes-api-scopes) section.

## API key header
  
An API key is an access token that a client provides when making API calls. It is a simple way to secure access and thus the most popular authentication method used with REST APIs.The key can be sent in the query string or as a request header. You are automatically assigned an API Key once you [create an account](https://www.infobip.com/docs/essentials/getting-started/create-an-account). Generate more keys and manage the existing ones through the Infobip [API key management](https://portal.infobip.com/settings/accounts/api-keys) page.
  
Here are some key facts about this method:

- API keys can be generated by calling the dedicated API method
- Keys can be revoked at any time which is useful when separating the API access rights across multiple applications or use cases
- Infobip API keys have a predefined expiry date to eventually become invalid

#### Example - HTTP client
  
The examples below show how to specify the API Key authentication when using [client libraries](https://github.com/infobip?q=infobip-api-*-client&type=&language=&sort=#org-profiles-repositories).
  
```curl
curl -L -g -X GET 'https://{baseUrl}/sms/2/text/advanced' /
-H 'Authorization: App 003026abc133714df1834b8638bb496e-8f4b3d9a-e931-478d-a994-28a725159ab9'
```

```java
Request request = new Request.Builder()
        .url("BASE_URL" + "/sms/2/text/advanced")
        .addHeader("Authorization", "App " + apiKey)
        .addHeader("Content-Type", "application/json")
        .addHeader("Accept", "application/json")
        .post(requestBody)
        .build();
```

```csharp
HttpClient client = new HttpClient();
client.BaseAddress = new Uri("BASE_URL");
 
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("App", "API_KEY");
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
```

#### Example - API client library
  
The examples below show how to prepare an HTTP request using API Key authentication. Note this request is much simpler than using a basic authentication request.
  
```java
ApiClient apiClient = ApiClient.forApiKey(ApiKey.from(API_KEY))
    .withBaseUrl(BaseUrl.from(BASE_URL))
    .build();
```

```csharp
var configuration = new Configuration()
{
    BasePath = "BASE_URL",
    ApiKeyPrefix = "App",
    ApiKey = "API_KEY"
};
```

### API scopes on API keys [#api-scopes-on-api-keys-api-key-header]

For details on API scopes, see the dedicated [API scopes](https://www.infobip.com/docs/essentials/api-essentials/api-authorization#api-scopes) section.

## IBSSO token header
  
IBSSO tokens are session-based meaning tokens are valid for a short amount of time. That ultimately makes this method more secure, but also requires more maintenance to keep authentication valid.
  
Typically, this kind of authentication is used in single sign-on scenarios where multiple sign-ins which to be avoided across the system. It may be also useful in scenarios when sensitive data needs to be handled centrally without the need to distribute it across various enterprise systems.
  
Here are some key facts about this method:

- All API requests are authenticated with a [session token](https://www.infobip.com/docs/api/platform/account-management/create-session)
- By default, IBSSO tokens will expire after 60 minutes after which a new token must be created
- If you want to create a new token but the previous one has not expired yet, you will first need to [destroy the session](https://www.infobip.com/docs/api/platform/account-management/destroy-session)
- You can shorten the session's length with a dedicated API call

### How to use IBSSO tokens [#how-to-use-ibsso-tokens-ibsso-token-header]

1. Make a call to create a session endpoint and take the token from the response.
2. Include `IBSSO` and the token in the Authorization header for all subsequent calls: `Authorization: IBSSO 2f9b4d31-2d0d-49a8-85f0-9b862bdca394`
3. Optionally, destroy the session to adjust the session's length to your needs. By default, the session will expire after 60 minutes.

### HTTP request [#http-request-ibsso-token-header]

- Create session
- Destroy session

### Obtain IBSSO token [#obtain-ibsso-token-ibsso-token-header]
  
Create a session by calling the **Create session** endpoint. The response will contain the token which can then be used in the HTTP header of the requests to other API endpoints such as [Send SMS](https://www.infobip.com/docs/api/platform/account-management/create-session).
  
```java
private static class IbssoResponse {
    public IbssoResponse() {
        super();
    }
 
    @JsonProperty("token")
    public String token;
 
    @JsonGetter("token")
    public String getToken() {
        return token;
    }
 
    @JsonSetter("token")
    public void setToken(String token) {
        this.token = token;
    }
}
 
String jsonBody = String.format("{\"username\":\"%s\",\"password\":\"%s\"}", "USERNAME", "PASSWORD");
 
RequestBody requestBody = RequestBody.create(MediaType.parse("application/json; charset=utf-8"), jsonBody);
 
Request request = new Request.Builder()
        .url("BASE_URL" + "/auth/1/session")
        .addHeader("Content-Type", "application/json")
        .addHeader("Accept", "application/json")
        .post(requestBody)
        .build();
 
OkHttpClient httpClient = new OkHttpClient().newBuilder().build();
Response response = httpClient.newCall(request).execute();
String responseBody = response.body().string();
System.out.println(responseBody);
 
IbssoResponse ibssoResponse = new ObjectMapper().readValue(responseBody, IbssoResponse.class);
 
return ibssoResponse.token;
```

```csharp
public class IbssoResponse
{
    [System.Text.Json.Serialization.JsonPropertyName("token")]
    public string Token { get; set; }
}
 
string username = "USERNAME";
string password = "PASSWORD";
 
HttpClient client = new HttpClient();
client.BaseAddress = new Uri("BASE_URL");
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
 
string body = $@"
{{
    ""username"": ""{username}"",
    ""password"": ""{password}""
}}";
 
HttpRequestMessage httpRequest = new HttpRequestMessage(HttpMethod.Post, "/auth/1/session");
httpRequest.Content = new StringContent(body, System.Text.Encoding.UTF8, "application/json");
 
var response = client.SendAsync(httpRequest).GetAwaiter().GetResult();
var responseContent = response.Content.ReadAsStringAsync().GetAwaiter().GetResult();
 
var responseObject = JsonSerializer.Deserialize(responseContent);
 
return responseObject.Token;
```

**Example - HTTP client**
  
The examples below show how to prepare the HTTP request. Note that this is almost identical to API Key authentication, but instead of `App` you will use `IBBSO` in the header.
  
```java
private static class IbssoResponse {
    public IbssoResponse() {
        super();
    }
 
    @JsonProperty("token")
    public String token;
 
    @JsonGetter("token")
    public String getToken() {
        return token;
    }
 
    @JsonSetter("token")
    public void setToken(String token) {
        this.token = token;
    }
}
 
String jsonBody = String.format("{\"username\":\"%s\",\"password\":\"%s\"}", "USERNAME", "PASSWORD");
 
RequestBody requestBody = RequestBody.create(MediaType.parse("application/json; charset=utf-8"), jsonBody);
 
Request request = new Request.Builder()
        .url("BASE_URL" + "/auth/1/session")
        .addHeader("Content-Type", "application/json")
        .addHeader("Accept", "application/json")
        .post(requestBody)
        .build();
 
OkHttpClient httpClient = new OkHttpClient().newBuilder().build();
Response response = httpClient.newCall(request).execute();
String responseBody = response.body().string();
System.out.println(responseBody);
 
IbssoResponse ibssoResponse = new ObjectMapper().readValue(responseBody, IbssoResponse.class);
 
return ibssoResponse.token;
```

```csharp
HttpClient client = new HttpClient();
client.BaseAddress = new Uri("BASE_URL");
 
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("IBSSO", "TOKEN");
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
```

**Example - API library**
  
When using any of the Infobip API [client libraries](https://github.com/infobip?q=infobip-api-*-client&type=&language=&sort=#org-profiles-repositories), you will need the same elements that you would for the API Key authentication, but instead of `App` you will use `IBBSO.`
  
```csharp
var configuration = new Configuration()
{
    BasePath = "BASE_URL",
    ApiKeyPrefix = "IBSSO",
    ApiKey = "TOKEN"
};
```

## OAuth 2.0
  
This type of authentication is the most secure option and is almost industry standard. Similar to using IBSSO tokens, you will use an access token you get from separate endpoint.
  
Here are some key facts about this method:

- The access token returned in response will expire within the time limit provided in seconds in the same response.
- Infobip acts as both a resource and an authorization server.
- A new token has to be created once the token expires. There is no automatic token retrieval.

For more details, see the official [OAuth 2.0](https://datatracker.ietf.org/doc/html/rfc6749) specification.
  
### How to use OAuth 2.0 [#how-to-use-oauth-20-oauth-20]

1. Make a call to get the access token and the expiration time from a separate endpoint.
2. Include `Bearer` and the token in the Authorization header for all subsequent calls until the token expires.
    `Authorization: Bearer eyJraWQiOiI5d29rWGRoSSIsInR5cCI6IkpXVCIsImFsZyI6IkhTMjU2In0.eyJzdWIiOiJERDIwMjAiLCJpc3MiOiJpbmZvYmlwLmNvbSIsImV4cCI6MTYzMzAwNDQwNiwiaWF0IjoxNjMzMDAwODA2LCJqdGkiOiJiMmJmODgyMS01OTcxLTRiOTMtYWVmNy0zM2QwMDNkMjIxNjcifQ.KvIIOmCKJETiB6xKOqBxvZYnYOa8RAulYhChBEmI4Os`

### HTTP request [#http-request-oauth-20]

- Create OAuth2 token

### Obtain OAuth token [#obtain-oauth-token-oauth-20]
  
Similarly to IBSSO tokens, you have to first obtain a token before making any API calls.
  
```java
private static class OauthResponse {
    public OauthResponse() {
        super();
    }
 
    @JsonProperty("access_token")
    private String accessToken;
    @JsonProperty("expires_in")
    private String expiresIn;
 
    @JsonGetter("access_token")
    public String getAccessToken() {
        return accessToken;
    }
 
    @JsonSetter("access_token")
    public void setAccessToken(String accessToken) {
        this.accessToken = accessToken;
    }
 
    @JsonGetter("expires_in")
    public String getExpiresIn() {
        return expiresIn;
    }
 
    @JsonSetter("expires_in")
    public void setExpiresIn(String expiresIn) {
        this.expiresIn = expiresIn;
    }
}
 
HttpPost post = new HttpPost(BASE_URL + "/auth/1/oauth2/token");
List  nvps = new ArrayList();
nvps.add(new BasicNameValuePair("client_id", username));
nvps.add(new BasicNameValuePair("client_secret", password));
nvps.add(new BasicNameValuePair("grant_type", "client_credentials"));
 
post.setEntity(new UrlEncodedFormEntity(nvps, HTTP.UTF_8));
 
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpResponse response = httpClient.execute(post);
System.out.println(response.getStatusLine());
 
String responseJson = EntityUtils.toString(response.getEntity());
System.out.println(responseJson);
 
OauthResponse oauthResponse = new ObjectMapper().readValue(responseJson, OauthResponse.class);
 
return oauthResponse.accessToken;
```

```csharp
public class OauthResponse
{
    [System.Text.Json.Serialization.JsonPropertyName("expires_in")]
    public int ExpiresIn { get; set; }
 
    [System.Text.Json.Serialization.JsonPropertyName("access_token")]
    public string AccessToken { get; set; }
}
 
string username = "USERNAME";
string password = "PASSWORD"; 
 
HttpClient client = new HttpClient();
client.BaseAddress = new Uri("BASE_URL");
 
var dict = new Dictionary<string, string>();
dict.Add("client_id", username);
dict.Add("client_secret", password);
dict.Add("grant_type", "client_credentials");
 
HttpRequestMessage httpRequest = new HttpRequestMessage(HttpMethod.Post, "/auth/1/oauth2/token");
httpRequest.Content = new FormUrlEncodedContent(dict);
 
var response = client.SendAsync(httpRequest).GetAwaiter().GetResult();
var responseContent = response.Content.ReadAsStringAsync().GetAwaiter().GetResult();
 
var responseObject = JsonSerializer.Deserialize<OauthResponse>(responseContent);
 
var accessToken = responseObject.AccessToken;
```

**Example - HTTP client**
  
The examples below show how to prepare an HTTP client request with a header.
  
```java
Request request = new Request.Builder()
        .url("BASE_URL" + "/sms/2/text/advanced")
        .addHeader("Authorization", "Bearer " + accessToken)
        .addHeader("Content-Type", "application/json")
        .addHeader("Accept", "application/json")
        .post(body)
        .build();
```

```csharp
HttpClient client = new HttpClient();
client.BaseAddress = new Uri("BASE_URL");
 
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", "ACCESS_TOKEN");
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
```

**Example - API library**
  
The examples below show how to prepare an HTTP request with headers.
  
```csharp
var configuration = new Configuration()
{
    BasePath = "BASE_URL",
    ApiKeyPrefix = "Bearer",
    ApiKey = "ACCESS_TOKEN"
};
```

## Errors
  
Commonly you will get the `401 Unauthorised` HTTP status code in response when there is a missing or invalid username or password.
  
```json
{
    "requestError": {
        "serviceException": {
            "messageId": "UNAUTHORIZED",
            "text": "Invalid login details"
        }
    }
}
```

### Library exceptions [#library-exceptions-errors]
  
When using one of the [libraries](https://github.com/infobip?q=infobip-api-*-client&type=&language=&sort=#org-profiles-repositories), make sure to handle API exceptions.
  
```java
try {
    SmsResponse smsResponse = sendSmsApi.sendSmsMessage(smsMessageRequest);
} catch (ApiException apiException) {
    apiException.getCode();
    apiException.getResponseHeaders();
    apiException.getResponseBody();
}
```

```csharp
try
{
    var result = api.SendSmsMessage(smsRequest);
}
catch(ApiException apiException)
{
    var errorCode = apiException.ErrorCode;
    var errorContent = apiException.ErrorContent;
}
```