How to integrate keycloak sms authentication by API?

Question

I have a keycloak server and Laravel application using custom KeycloakProvider:

public function loginByEmail(string $email, string $password): SsoTokens
{
    try {
        $data = $this->realmEndpoint->makeRequest(
            HttpClientProvider::METHOD_POST,
            self::KEYCLOAK_AUTH_URL,
            [
                'client_id' => config('services.keycloak.realm_client'),
                'client_secret' => config('services.keycloak.realm_secret'),
                'grant_type' => 'password',
                'username' => $email,
                'password' => $password,
                'scope' => 'openid'
            ]
        );
    } catch (TransportUnauthorizedException $e) {
        throw new UnauthorizedException($e);
    } catch (HttpClientException $e) {
        throw new TransportException($e);
    }

    return $this->extractTokens($data);
}

Now my goal is to set up basic SMS authentication by the user's mobile phone number. I found some tools (1, 2), but they don't provide API, just HTML pages. Is there a solution?

Answer 1

I found a solution. To login without knowing someone's password:

1. Send SMS;
2. Confirm phone number by a code;
3. Get the keycloak ID of a target user;
4. Log in as a user having the right to impersonate;
5. Exchange tokens with a target user.

TOKEN_EXCHANGE keycloak feature required.

Steps 1-3 I implemented with Laravel, steps 4-5 with Keycloak APIs:

public function loginByUserId(string $userId): SsoTokens
    {
        try {
            $impersonatorData = $this->realmEndpoint->makeRequest(
                HttpClientProvider::METHOD_POST,
                self::KEYCLOAK_AUTH_URL,
                [
                    'client_id' => config('services.keycloak.realm_client'),
                    'client_secret' => config('services.keycloak.realm_secret'),
                    'grant_type' => 'password',
                    'username' => config('services.keycloak.admin_username'),
                    'password' => config('services.keycloak.admin_password'),
                    'scope' => 'openid',
                ]
            );

            $data = $this->realmEndpoint->makeRequest(
                HttpClientProvider::METHOD_POST,
                self::KEYCLOAK_AUTH_URL,
                [
                    'client_id' => config('services.keycloak.realm_client'),
                    'client_secret' => config('services.keycloak.realm_secret'),
                    'grant_type' => 'urn:ietf:params:oauth:grant-type:token-exchange',
                    'requested_subject' => $userId,
                    'subject_token' => $impersonatorData['access_token'],
                    'scope' => 'openid',
                ]
            );
        } catch (TransportUnauthorizedException $e) {
            throw new UnauthorizedException($e);
        } catch (HttpClientException $e) {
            throw new TransportException($e);
        }

        return $this->extractTokens($data);
    }