openapi: 3.0.3
info:
title: Call Forwarding Signal Age Verification OTP Management API
description: '# Overview
The Call Forwarding Signal API provides the API Consumer with
information about the status of the Call Forwarding Service on a specific
phone number. The main scope of the Call Forwarding Signal API is "anti
Fraud" to avoid fraudsters to use the Call Forwarding Service to carry
on a scam. Other use cases are anyway supported by the Call Forwarding
Signal API that also
provides additional endpoints to detect the general Call Forwarding
Service settings.
# Introduction
The Call Forwarding Service is provided by the Network to a phone
number. This service redirects the incoming call to that phone number
to an alternative destination such as another phone number or a voice mail
system. There are two main types of call forwarding settings:
unconditional and conditional.
The Call Forwarding Signal API can be invoked to detect if the unconditional
call forwarding service is active. The Call Forwarding Signal API can also
be invoked to
get the general status of the Call Forwarding Service (inactive,
conditional, unconditional). If conditional call forwarding is active,
the different type of settings are returned (''conditional_busy'',
''conditional_not_reachable'', ''conditional_no_answer'').
**Example use cases:**
[**Bank Frauds**](https://github.com/camaraproject/CallForwardingSignal/discussions/3#discussioncomment-8694420)
[**Alert Interception**](https://github.com/camaraproject/CallForwardingSignal/discussions/3#discussioncomment-8701847)
[**Call Forwarding Verification**](https://github.com/camaraproject/CallForwarding\Signal/discussions/3#discussioncomment-8915595)
# Quick Start
The Call Forwarding Signal API is a REST API based on the
CreateCallForwardingSignal resource.
This resource can be used, by the API Consumer, to specify the phone number
on which the Call Forwarding Service status must be verified, in case of
two-legged authentication. If three-legged authentication is used the phone
number is instead detected, by the API Producer, from the access token.
Before starting to use the Call Forwarding API, the developer needs to know
about the below specified details:
**phoneNumber**
This is the end user phone number. The Call Forwarding Signal API verifies
if a call forwarding
service is active on this phone number. Note: this parameter must be
must be provided/valued only in case of two-legged authentication.
In case of three-legged authentication the phone number is retrieved by
the access token.
**CreateCallForwardingSignal**
This is the resource the API Consumer uses to define the phone number to
be verified about the status of the Network Call Forwarding service.
**UnconditionalCallForwardingSignal**
This is the resource the API Consumer gets back, containing the information
about the Unconditional Call Forwarding Service status for the given phone
number (PhoneNumber).
**CallForwardingSignal**
This is the resource the API Consumer gets back, containing the information
about the general status of the Network Call Forwarding service for the
specified phone number.
The Call Forwarding Signal API provides two endpoints fulfilling the
following intents:
- **unconditional-call-forwardings**: Is the unconditional call fwd service
active on a specific phone number?
- **call-forwardings**: Which is the status of the call forwarding for a
specific phone number?
# API Documentation
## Details
The Call Forwarding Signal API is invoked by an API Consumer after the
Consent Management flow.
The API Consumer can request the API Producer for the status of the
Unconditional Call Forwarding service using the
unconditional-call-forwardings POST method. A boolean, with the information
about the activation status of the call forwarding service, will be
provided back via the UnconditionalCallForwardingSignal resource.
The API Consumer can also request the API Producer for the generic status of
the Call Forwarding service using the call-forwardings POST method. An array
of strings with the information of the type of active call forwarding
services will be provided back via the CallForwardingSignal resource.
# Authorization and authentication
The "Camara Security and Interoperability Profile" provides details of how
an API consumer requests an access token. Please refer to Identity and
Consent Management
(https://github.com/camaraproject/IdentityAndConsentManagement/)
for the released version of the profile.
The specific authorization flows to be used will be agreed upon during the
onboarding process, happening between the API consumer and the API
provider, taking into account the declared purpose for accessing the API,
whilst also being subject to the prevailing legal framework dictated by
local legislation.
In cases where personal data is processed by the API and users can
exercise their rights through mechanisms such as opt-in and/or opt-out,
the use of three-legged access tokens is mandatory. This ensures that
the API remains in compliance with privacy regulations, upholding the
principles of transparency and user-centric privacy-by-design.
# Identifying the phone number from the access token
This API requires the API consumer to identify a phone number as the
subject of the API as follows:
- When the API is invoked using a two-legged access token, the subject
will be identified from the optional `phoneNumber` object field, which
therefore MUST be provided.
- When a three-legged access token is used however, this optional
identifier MUST NOT be provided, as the subject will be uniquely
identified from the access token.
This approach simplifies API usage for API consumers using a
three-legged access token to invoke the API by relying on the
information that is associated with the access token and was
identified during the authentication process.
## Error handling:
- If the subject cannot be identified from the access token and the
optional `phoneNumber` object field is not included in the request, then
the server will return an error with the
`422 MISSING_IDENTIFIER` error code.
- If the subject can be identified from the access token and the
optional `phoneNumber` object field is also included in the request, then
the server will return an error with the `422 UNNECESSARY_IDENTIFIER`
error code. This will be the case even if the same device is
identified by these two methods, as the server is unable to make
this comparison.
# Additional CAMARA error responses
The list of error codes in this API specification is not exhaustive.
Therefore the API specification may not document some non-mandatory error
statuses as indicated in `CAMARA API Design Guide`.
Please refer to the `CAMARA_common.yaml` of the Commonalities Release
associated to this API version for a complete list of error responses.
The applicable Commonalities Release can be identified in the
`API Readiness Checklist` document associated to this API version.
As a specific rule, error `501 - NOT_IMPLEMENTED` can be only a possible
error response if it is explicitly documented in the API.
# FAQ''s
(FAQs will be added in a later version of the documentation)
'
version: wip
license:
name: Apache 2.0
url: https://www.apache.org/licenses/LICENSE-2.0.html
x-camara-commonalities: 0.6
servers:
- url: '{apiRoot}/call-forwarding-signal/vwip'
variables:
apiRoot:
default: http://localhost:9091
description: API root, defined by the service provider, e.g. `api.example.com` or `api.example.com/somepath`
tags:
- name: OTP Management
description: API operations to manage OTP codes
paths:
/send-code:
post:
tags:
- OTP Management
summary: Sends a message including an OTP code to the given phone number
description: Sends an SMS with the desired message and an OTP code to the received phone number.
operationId: sendCode
parameters:
- $ref: '#/components/parameters/x-correlator'
requestBody:
content:
application/json:
schema:
$ref: '#/components/schemas/SendCodeBody'
required: true
responses:
'200':
description: OK
headers:
x-correlator:
$ref: '#/components/headers/x-correlator'
content:
application/json:
schema:
$ref: '#/components/schemas/SendCodeResponse'
'400':
$ref: '#/components/responses/Generic400'
'401':
$ref: '#/components/responses/Generic401'
'403':
$ref: '#/components/responses/SendCodeForbiddenError403'
'404':
$ref: '#/components/responses/Generic404'
'429':
$ref: '#/components/responses/Generic429'
security:
- openId:
- one-time-password-sms:send-validate
/validate-code:
post:
tags:
- OTP Management
summary: Verifies the OTP received as input
description: Verifies the code is valid for the received authenticationId
operationId: validateCode
parameters:
- $ref: '#/components/parameters/x-correlator'
requestBody:
content:
application/json:
schema:
$ref: '#/components/schemas/ValidateCodeBody'
required: true
responses:
'204':
description: The OTP was successfully validated
headers:
x-correlator:
$ref: '#/components/headers/x-correlator'
'400':
$ref: '#/components/responses/ValidateCodeBadRequestError400'
'401':
$ref: '#/components/responses/Generic401'
'403':
$ref: '#/components/responses/Generic403'
'404':
$ref: '#/components/responses/Generic404'
'429':
$ref: '#/components/responses/Generic429'
security:
- openId:
- one-time-password-sms:send-validate
components:
schemas:
SendCodeResponse:
description: Structure to provide authentication identifier
type: object
properties:
authenticationId:
$ref: '#/components/schemas/AuthenticationId'
required:
- authenticationId
AuthenticationId:
type: string
description: unique id of the verification attempt the code belongs to.
maxLength: 36
example: ea0840f3-3663-4149-bd10-c7c6b8912105
XCorrelator:
type: string
pattern: ^[a-zA-Z0-9-_:;.\/<>{}]{0,256}$
example: b4333c46-49c0-4f62-80d7-f0ef930f1c46
ValidateCodeBody:
description: Strcuture to request code verification
type: object
properties:
authenticationId:
$ref: '#/components/schemas/AuthenticationId'
code:
$ref: '#/components/schemas/Code'
required:
- authenticationId
- code
ErrorInfo:
description: Structure to describe error
type: object
required:
- status
- code
- message
properties:
status:
type: integer
description: HTTP response status code
code:
type: string
description: A human-readable code to describe the error
message:
type: string
description: A human-readable description of what the event represents
Code:
type: string
description: temporal, short code to be validated
maxLength: 10
example: AJY3
Message:
type: string
description: Message template used to compose the content of the SMS sent to the phone number. It must include the following label indicating where to include the short code `{{code}}`
pattern: .*\{\{code\}\}.*
maxLength: 160
example: '{{code}} is your short code to authenticate with Cool App via SMS'
SendCodeBody:
description: Structure to request sending a code to a phone number
type: object
properties:
phoneNumber:
$ref: '#/components/schemas/PhoneNumber'
message:
$ref: '#/components/schemas/Message'
required:
- message
- phoneNumber
PhoneNumber:
description: A public identifier addressing a telephone subscription. In mobile networks it corresponds to the MSISDN (Mobile Station International Subscriber Directory Number). In order to be globally unique it has to be formatted in international format, according to E.164 standard, prefixed with '+'.
type: string
pattern: ^\+[1-9][0-9]{4,14}$
example: '+346661113334'
responses:
ValidateCodeBadRequestError400:
description: "Problem with the client request. In addition to regular scenario of `INVALID_ARGUMENT`, another scenarios may exist:\n - Too many unsuccessful attempts (`{\"code\": \"ONE_TIME_PASSWORD_SMS.VERIFICATION_FAILED\",\"message\": \"The maximum number of attempts for this authenticationId was exceeded without providing a valid OTP\"}`)\n - Expired authenticationId (`{\"code\": \"ONE_TIME_PASSWORD_SMS.VERIFICATION_EXPIRED\",\"message\": \"The authenticationId is no longer valid\"}`)\n - OTP is not valid for the provided authenticationId (`{\"code\": \"ONE_TIME_PASSWORD_SMS.INVALID_OTP\",\"message\": \"The provided OTP is not valid for this authenticationId\"}`)"
headers:
x-correlator:
$ref: '#/components/headers/x-correlator'
content:
application/json:
schema:
allOf:
- $ref: '#/components/schemas/ErrorInfo'
- type: object
properties:
status:
enum:
- 400
code:
enum:
- INVALID_ARGUMENT
- OUT_OF_RANGE
- ONE_TIME_PASSWORD_SMS.VERIFICATION_FAILED
- ONE_TIME_PASSWORD_SMS.VERIFICATION_EXPIRED
- ONE_TIME_PASSWORD_SMS.INVALID_OTP
examples:
GENERIC_400_OUT_OF_RANGE:
description: Out of Range. Specific Syntax Exception used when a given field has a pre-defined range or a invalid filter criteria combination is requested
value:
status: 400
code: OUT_OF_RANGE
message: Client specified an invalid range.
GENERIC_400_INVALID_ARGUMENT:
value:
status: 400
code: INVALID_ARGUMENT
message: Client specified an invalid argument, request body or query param
OTP_VALIDATION_400_VERIFICATION_FAILED:
value:
status: 400
code: ONE_TIME_PASSWORD_SMS.VERIFICATION_FAILED
message: The maximum number of attempts for this authenticationId was exceeded without providing a valid OTP
OTP_VALIDATION_400_VERIFICATION_EXPIRED:
value:
status: 400
code: ONE_TIME_PASSWORD_SMS.VERIFICATION_EXPIRED
message: The authenticationId is no longer valid
OTP_VALIDATION_400_INVALID_OTP:
value:
status: 400
code: ONE_TIME_PASSWORD_SMS.INVALID_OTP
message: The provided OTP is not valid for this authenticationId
Generic401:
description: Authentication problem with the client request
headers:
x-correlator:
$ref: '#/components/headers/x-correlator'
content:
application/json:
schema:
allOf:
- $ref: '#/components/schemas/ErrorInfo'
- type: object
properties:
status:
enum:
- 401
code:
enum:
- UNAUTHENTICATED
examples:
GENERIC_401_UNAUTHENTICATED:
description: Request cannot be authenticated
value:
status: 401
code: UNAUTHENTICATED
message: Request not authenticated due to missing, invalid, or expired credentials.
Generic403:
description: Client does not have sufficient permission
headers:
x-correlator:
$ref: '#/components/headers/x-correlator'
content:
application/json:
schema:
allOf:
- $ref: '#/components/schemas/ErrorInfo'
- type: object
properties:
status:
enum:
- 403
code:
enum:
- PERMISSION_DENIED
examples:
GENERIC_403_PERMISSION_DENIED:
description: Permission denied. OAuth2 token access does not have the required scope or when the user fails operational security
value:
status: 403
code: PERMISSION_DENIED
message: Client does not have sufficient permissions to perform this action.
Generic429:
description: Either out of resource quota or reaching rate limiting
headers:
x-correlator:
$ref: '#/components/headers/x-correlator'
content:
application/json:
schema:
allOf:
- $ref: '#/components/schemas/ErrorInfo'
- type: object
properties:
status:
enum:
- 429
code:
enum:
- QUOTA_EXCEEDED
- TOO_MANY_REQUESTS
examples:
GENERIC_429_QUOTA_EXCEEDED:
description: Request is rejected due to exceeding a business quota limit
value:
status: 429
code: QUOTA_EXCEEDED
message: Out of resource quota.
GENERIC_429_TOO_MANY_REQUESTS:
description: Access to the API has been temporarily blocked due to rate or spike arrest limits being reached
value:
status: 429
code: TOO_MANY_REQUESTS
message: Rate limit reached.
Generic400:
description: Problem with the client request
headers:
x-correlator:
$ref: '#/components/headers/x-correlator'
content:
application/json:
schema:
allOf:
- $ref: '#/components/schemas/ErrorInfo'
- type: object
properties:
status:
enum:
- 400
code:
enum:
- INVALID_ARGUMENT
examples:
GENERIC_400_INVALID_ARGUMENT:
description: Invalid Argument. Generic Syntax Exception
value:
status: 400
code: INVALID_ARGUMENT
message: Client specified an invalid argument, request body or query param.
SendCodeForbiddenError403:
description: "Client does not have sufficient permissions to perform this action.\nIn addition to regular scenario of `PERMISSION_DENIED`, another scenarios may exist:\n - Too many code requests were sent (`{\"code\": \"ONE_TIME_PASSWORD_SMS.MAX_OTP_CODES_EXCEEDED\",\"message\": \"Too many OTPs have been requested for this MSISDN. Try later.\"}`)\n - The given phoneNumber can't receive an SMS due to business reasons in the operator, e.g. fraud, receiving SMS is not supported, etc (`{\"code\": \"ONE_TIME_PASSWORD_SMS.PHONE_NUMBER_NOT_ALLOWED\",\"message\": \"Phone_number can't receive an SMS due to business reasons in the operator.\"}`)\n - The given phoneNumber is blocked to receive SMS due to any blocking business reason in the operator (`{\"code\": \"ONE_TIME_PASSWORD_SMS.PHONE_NUMBER_BLOCKED\",\"message\": \"Phone_number is blocked to receive SMS due to any blocking business reason in the operator.\"}`)"
headers:
x-correlator:
$ref: '#/components/headers/x-correlator'
content:
application/json:
schema:
allOf:
- $ref: '#/components/schemas/ErrorInfo'
- type: object
properties:
status:
enum:
- 403
code:
enum:
- PERMISSION_DENIED
- ONE_TIME_PASSWORD_SMS.MAX_OTP_CODES_EXCEEDED
- ONE_TIME_PASSWORD_SMS.PHONE_NUMBER_NOT_ALLOWED
- ONE_TIME_PASSWORD_SMS.PHONE_NUMBER_BLOCKED
examples:
GENERIC_403_PERMISSION_DENIED:
value:
status: 403
code: PERMISSION_DENIED
message: Client does not have sufficient permissions to perform this action
OTP_VALIDATION_403_MAX_OTP_CODES_EXCEEDED:
value:
status: 403
code: ONE_TIME_PASSWORD_SMS.MAX_OTP_CODES_EXCEEDED
message: Too many OTPs have been requested for this MSISDN. Try later.
OTP_VALIDATION_403_PHONE_NUMBER_NOT_ALLOWED:
value:
status: 403
code: ONE_TIME_PASSWORD_SMS.PHONE_NUMBER_NOT_ALLOWED
message: Phone_number can't receive an SMS due to business reasons in the operator.
OTP_VALIDATION_403_PHONE_NUMBER_BLOCKED:
value:
status: 403
code: ONE_TIME_PASSWORD_SMS.PHONE_NUMBER_BLOCKED
message: Phone_number is blocked to receive SMS due to any blocking business reason in the operator.
Generic404:
description: Resource Not Found
headers:
x-correlator:
$ref: '#/components/headers/x-correlator'
content:
application/json:
schema:
allOf:
- $ref: '#/components/schemas/ErrorInfo'
- type: object
properties:
status:
enum:
- 404
code:
enum:
- NOT_FOUND
examples:
GENERIC_404_NOT_FOUND:
description: Resource is not found
value:
status: 404
code: NOT_FOUND
message: The specified resource is not found.
headers:
x-correlator:
description: Correlation id for the different services
schema:
$ref: '#/components/schemas/XCorrelator'
parameters:
x-correlator:
name: x-correlator
in: header
description: Correlation id for the different services
schema:
$ref: '#/components/schemas/XCorrelator'
securitySchemes:
openId:
description: to support Consent Management
type: openIdConnect
openIdConnectUrl: https://example.com/.well-known/openid-configuration
externalDocs:
description: Product documentation at CAMARA
url: https://github.com/camaraproject/CallForwardingSignal