Authorization to APIs

This page describes how to authenticate and authorize your calls to our APIs using standard OpenId Connect

Create a service account

Service accounts provide an identity for your processes to access our APIs. They can authenticate themselves using either a Public Key or Password Authentication.

We recommend that you use Public key authentication which doesn't require sending secrets over the network.

Public Key Authentication

You will need a private key to sign your access token requests, and a corresponding public key that our identity server will use to verify the signature.

Generate an RSA private key

openssl genrsa -des3 -out private.pem 2048

OpenSSL will ask you for a passphrase that will be used to encrypt the private key file.

Generate the corresponding public key

openssl rsa -in private.pem -outform PEM -pubout -out public.pem

Enter the private key passphrase when prompted.

Create the service account

Please reach out to your Technical Consultant to request a service account to be created. Specify that you chose Public Key Authentication and provide your public key. They will give you in return a Client ID and tenant ID that you will need in the following steps.

Password Authentication

Obtaining access tokens

Access tokens can be obtained using the OpenId Connect Client Credentials grant.

The token endpoint to use is: https://iam.attraqt.io/auth/realms/${tenantId}/protocol/openid-connect/token where ${tenantId} is the identifier of your Attraqt tenant.

This endpoint is rate-limited at 10 requests per seconds, which is more than enough when tokens are properly cached and reused until expiration. Hitting the rate limit will cause HTTP 429 errors. It is recommended to implement a retry strategy to handle those errors (see also https://github.com/Attraqt/product-discovery-documentation/blob/main/new-docs/sending-and-managing-data/sending-product-data/item-catalog-management/troubleshooting-api-errors.md).

The process differs depending on whether you are using Public Key or Password authentication.

Public Key Authentication

Service accounts with the JWT authentication method need to send a JWT signed with their private key to get access tokens, as described in RFC 7523.

The basic steps are:

1. Build a JWT with the following claims:

   • iss: your client ID (c.f. previous step)

   • sub: also your client ID

   • aud: the token endpoint

   • jti: a uniquely generated ID

   • exp: a rather short expiration time, one minute is more than enough.

2. Sign the JWT with the private key you generated earlier.

3. Send a client_credentials grant request to the authorization server token endpoint.

4. Use the access_token in the response to obtain Requesting Party Tokens that will be needed to authenticate your requests to Attraqt private APIs (see below).

Node.js example

const { promisify } = require('util');
const { readFile } = require('fs');
const { sign } = require('jsonwebtoken');
const uuid = require('uuid');
const request = require('request-promise-native');

// ...

// replace this by the path of the PEM file containing your encrypted private key
// (c.f. "Create a Service Account" section)
const encryptedPrivateKeyPem = await promisify(readFile)('/path/to/my/pkcs8/key.pem', 'utf8');
// replace this by the passphrase you used when generating your private key
const encryptedPrivateKeyPassphrase = 'yourSecretPassphrase'
// replace this by the client ID of your service account
// (c.f. "Create a Service Account" section)
const serviceAccountClientId = 'your-client-id';
// replace this by your Attraqt tenant ID
const tenantId = "myTenantId";
const tokenEnpoint = `https://iam.attraqt.io/auth/realms/${tenantId}/protocol/openid-connect/token`;

const jwt = await promisify(sign)(
    {},
    {
        key: encryptedPrivateKeyPem,
        passphrase: encryptedPrivateKeyPassphrase
    },
    {
        jwtid: uuid.v4(),
        issuer:  serviceAccountClientId,
        subject:  serviceAccountClientId,
        audience:  tokenEnpoint,
        expiresIn:  "1min",
        algorithm:  "RS256"
    }
);

const credentials = await request({
    method: 'POST',
    uri: tokenEnpoint,
    form: {
        grant_type: 'client_credentials',
        client_id: serviceAccountClientId,
        client_assertion_type: 'urn:ietf:params:oauth:client-assertion-type:jwt-bearer',
        client_assertion: jwt,
    },
    json: true,
});

const expiresIn = kcCredentials.expires_in; // seconds
const authorizationHeader = `${kcCredentials.token_type} ${kcCredentials.access_token}`;
// Cache the authorization header and use it in your
// calls to Attraqt APIs until its expiration

Java example

To work with the Java SDK, it is easier to convert your private key to the PKCS12 format:

openssl pkcs12 -export -nocerts -inkey private.pem -out key.p12 -name your-key-alias

And you can generate JWTs with Nimbus OAuth 2.0 SDK:

• Apache Maven:

<dependency>
  <groupId>com.nimbusds</groupId>
  <artifactId>oauth2-oidc-sdk</artifactId>
  <version>9.2</version>
</dependency>

• Gradle:

implementation 'com.nimbusds:oauth2-oidc-sdk:9.2'

Sample Code

// replace this by the path of the PKCS12 file containing your private key
File p12File = new File("/path/to/my/pkcs12/key.p12");
// replace this by the passphrase you used when generating your PKCS12 file
char[] p12Passphrase = "yourSecretPassphrase".toCharArray();
// replace this by the key alias you used when generating your PKCS12 file
String keyAlias = "your-key-alias";
// replace this by the client ID of your service account
// (c.f. "Create a Service Account" section)
ClientID serviceAccountClientId = new ClientID("your-client-id");
// replace this by your Attraqt tenant ID
String tenantId = "myTenantId";
URI tokenEnpoint = new URI("https://iam.attraqt.io/auth/realms/master/protocol/"+tenantId+"/token");

KeyStore store = KeyStore.getInstance("PKCS12");
try(InputStream p12stream = new FileInputStream(p12File)){
    store.load(p12stream, p12Passphrase);
}
Key key = store.getKey(keyAlias, p12Passphrase);

HTTPResponse httpResponse = new TokenRequest(
        tokenEnpoint,
        new PrivateKeyJWT(
                serviceAccountClientId,
                tokenEnpoint,
                JWSAlgorithm.RS256,
                (RSAPrivateKey)key,
                null,
                null
        ),
        new ClientCredentialsGrant()
).toHTTPRequest().send();

Object response = OIDCTokenResponseParser.parse(httpResponse);
if(response instanceof OIDCTokenResponse){
    AccessToken accessToken = ((OIDCTokenResponse)response).getOIDCTokens().getAccessToken();
    long expiresIn = accessToken.getLifetime(); // seconds
    String authorizationHeader = accessToken.toAuthorizationHeader();
    // Cache the authorization header and use it in your
    // calls to Attraqt APIs until its expiration
} else {
    String errorDescription = ((TokenErrorResponse)response).getErrorObject().getDescription()
    System.err.println("Error getting access token: " + errorDescription);
}

Password Authentication

Authenticating API calls

Calls to the Attraqt API must be authenticated with an Authorization header of type Bearer containing the acess token, for example:

curl -x GET \
  https://items.attraqt.io/catalogs/active?tenant=${tenant}&environment=${environment}
  -H "Authorization: Bearer ${access_token}"

You can use the access token as many times as you want before its expiration.

You must reuse access tokens as much as possible because calling the token endpoint is time and resource-consuming.

Access token expiration

Access tokens expire after a time given in the expires_in field of the identity server response. You will then need to get a new one using the same HTTP query.