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NZ Banking Data Security Profile v2.0.2

NZ Banking Data Security Profile v2.0.2

 

Version Control

Version

Date

Author

Comments

Version

Date

Author

Comments

v1.0.0

May 10, 2019 

Payments NZ

Baseline from v1.0.0-draft2

v2.0-draft2

Sep 10, 2019 

@Gavin Wong (Unlicensed)

Restructuring for v2.0

v2.0-draft3

Sep 17, 2019 

@Gavin Wong (Unlicensed)

Additions:

Updates:

  • References to Intent Id to "ConsentId" to unify the specifications

  • Separate section for the "NZ Read and Write API Security Profile" which extends the [FAPI Read+Write profile]

  • In 5.2.2.6 updated to "shall issue an ID Token in the token response" as the openid scope must be requested by the Third Party

  • Updated draft3-ImplementationGuide section:

    • To have (1) one example of the Hybrid Flow for the Payment Initiation API and (2) one example of the Decoupled Flow for the Account Information API

    • With updated examples for v2.0 API endpoint names and payloads

  • Updated state to be mandatory in the Hybrid Flow Authorization Request

  • Updated openbanking_intent_id to ConsentId

  • Updated urn:openbanking to urn:apicentre as per Technical Decision - 001 - Namespacing Token Claims

  • Updated nonce to be required "The API Provider must be replay the supplied nonce parameter in any ID Token response."

  • Updated at_hash to be optional in ID Token response

  • Clarification that a Confidential Client "shall accept and verify signed ID Tokens (JWS)"

  • Clarification that "OpenID Connect Request Object values (in the JWT) supersede those which are passed using the OAuth 2.0 request query parameter syntax." in the draft3-RequestObject

  • Clarifications on the claims request parameter in the draft3-RequestObject

  • Clarified that the ID Token sub shall always be populated with the ConsentId as per Technical Decision - 012 - Sub in ID Token

Removed:

  • From draft3-JWKSEndpoints

    • "Each API Provider will host their own JWKS endpoint. Upon issuance of a certificate a JWK Set will be created or updated for a given Third Party."

    • "The private key must have been used by the issuer to get a signing certificate issued from OB."

  • Reference to public clients as OPs are not supporting this functionality

  • References to the request_uri as this functionality is not supported

  • References to the userinfo endpoint as this functionality is not supported

  • In NZ Read and Write API Security Profile 5.2.2

    • Removed client_secret_basic and client_secret_post

    • Removed client_secret_jwt

  • As how to "authenticate the confidential client at the token endpoint" now aligns with FAPI-RW - have removed the variation on authentication methods

  • References to acr as this was optional to support and no guidance is given on how to support

  • From Non-Normative examples of Hybrid Flow - removed at_hash from ID Token as this is not required with the response type "code id_token"

  • Removed support for RSASSA-PKCS1-v1_5 (e.g. RS256) from 8.6JWSAlgorithmConsiderations and 7.10AlgorithmConsiderations as per Technical Decision - 013 - JWS Signing Algorithms

  • Removed references to azp as per Technical Decision - 014 - ID Token Authorized Party Field

  • Removed references to amr as per Technical Decision - 015 - ID Token Authentication Methods References

Errata:

  • Updated 8.2.1 to state "Authorization servers must not support the Request Object Endpoint (request_uri)"

  • "The scope parameter must contain openid" as the profile mandates the hybrid flow

  • "Third Parties must specify code id_token" as the profile mandates the hybrid flow

v2.0-rc2

Jan 3, 2020

@Gavin Wong (Unlicensed)

Updates:

  • Clarified in Unspecified Behaviour section that “The implementation guide does not illustrate the following configurations in this section.”

  • Updated unspecified behaviour for “Client Credentials Grant Type (scope=openid email profile)”

Removed:

  • Section on “Notation Conventions”

v2.0.0

Mar 31, 2020

@Gavin Wong (Unlicensed)

Errata:

  • Updated references to “third_party_client_credential” for consistency

v2.0.1

Jul 17, 2020

@Gavin Wong (Unlicensed)

No change

v2.0.2

Nov 5, 2022

@Nigel Somerfield

No change

Introduction

This document is based on the OpenID Foundation's Financial-grade API Read+Write specification FAPI-RW, which in turn is based on the Read only specification document FAPI. In addition, the Financial-grade API: Client Initiated Backchannel Authentication Profile FAPI-CB has been incorporated, to support a decoupled authentication flow. The NZ Banking Data profile will further shape these profiles in some cases tightening restrictions and in others loosening requirements using keywords. Please see the introduction to FAPI-RW for a general introduction to the aims of this document.

The NZ Banking Data Profile outlines the differences between the FAPI-RW and FAPI-CB with clauses and provisions necessary to reduce delivery risk for API Providers.

Security Architecture

OAuth 2.0

OAuth 2.0 will be the foundational framework for API Security for the NZ Banking Data API Standard. OAuth 2.0 itself is a framework which can be deployed in many ways, some of them completely incompatible with financial models. In order to securely use the OAuth 2.0 framework, a profile must exist by which both Third Parties and API Providers are certified to have correctly configured their clients and servers.

OIDC Core

The OpenID Connect Request object uses exactly the same claims object for specifying claim names, priorities, and values as OAuth 2.0. However if the Request object is used, the Claims object becomes a member in an assertion that can be signed and encrypted, allowing the API Provider to authenticate the request from the Third Party and ensure it hasn't been tampered with. The OpenID Connect Request object can either be passed as a query string parameter, or can be referenced at an endpoint that could theoretically be protected by MATLS. The use of JWT Request objects by reference is not supported due a number of delivery risks and remaining security concerns.

In addition to specifying a ticket, the Third Party can optionally require a minimum strength of authentication context or request to know how long ago the user was actually authenticated. Multiple tickets could be passed if necessary. Everything is fully specified. Vendors who implement this feature are not creating a one-off proprietary feature, they are simply supporting the OpenID Connect standard.

Full accountability is available as required by all participants. Not only can the API Provider prove that they received the original request from the Third Party, but the Third Party can prove that the access token that comes back was the token that was intended to be affiliated to this specific ConsentId.

OIDC Client Initiated Backchannel Authentication

The OIDC Client Initiated Backchannel Authentication (CIBA) profile enables a Client (Third Party) to initiate the authentication of the end-user (Customer) with the OpenID Provider (API Provider) in an out of band mechanism. This direct out of band mechanism between the Third Party and API Provider means that the Customer is not redirected to authenticate through the Customer's browser (or consumption device).

FAPI

The Financial API working group in the OpenID Foundation has created a draft standard for configuration of Financial-grade API security regimes. If any FAPI-compliant vendor can participate in the NZ Banking Data API ecosystem, it means that vendors can work to the standard and reach many customers, rather than having to create different solutions for different banking platforms. The FAPI profiles apply to both OIDC Core and OIDC CIBA profiles.

Scope

This part of the document specifies the method of

  • Applications to obtain the OAuth tokens in an appropriately secure manner for financial data access;

  • Applications to use OpenID flows to identify the Customer; and

  • Using tokens to interact with the REST endpoints that provides financial data;

This document is applicable to higher risk use cases which includes commercial and investment banking.

Normative References

The following referenced documents are strongly recommended to be used in conjunction with this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

Terms and Definitions

For the purpose of this document, the terms defined in [FAPI ReadOnly profile] FAPI, [FAPI Read+Write profile] FAPI-RW, [OpenID Connect Core] OIDC, [OpenID Connect Client Initiated Backchannel Authentication Flow] CIBA, and [FAPI: Client Initiated Backchannel Authentication Profile] FAPI-CB apply.

Symbols and Abbreviated Terms

  • API Provider - provides APIs in a manner that complies with the API Standards (e.g. Account Information and Payment Initiation APIs), and connects those APIs with a Third Party.

  • Third Party - the entity that consumes an API in a manner that complies with the API Standards.

  • Customer - a natural or legal person that operates banking accounts.

NZ Read and Write API Security Profile

The NZ Read and Write API Security Profile extends from [FAPI Read+Write profile] FAPI-RW.

This section identifies variations from FAPI-RW and the numbered section references where there is a variation in FAPI-RW.

Read and Write API Security Profile Variations

5.2 Read and Write API Security Provisions

5.2.1 Introduction

The NZ Banking Data API Security Profile does not distinguish between the security requirements from a technical level between "read" and "write" resources. The security requirements for accessing Customer resources held at API Providers requires more protection level than a basic OAuth 2.0 (RFC6749) supports.

As a profile of The OAuth 2.0 Authorization Framework, this document mandates the following to the NZ Banking Data APIs.

5.2.2 Authorization Server

The Authorization Server

  1. shall only support confidential clients;

  2. shall secure its token endpoint using mutually authenticated TLS;

  3. shall only support the response_type value code id_token;

  4. shall require the ConsentId to be passed in the authorisation request as an essential claim;

  5. shall issue an ID Token in the token response as in Section 3.1.3.3 of OIDC with its "sub" value corresponding to the ConsentId;

  6. may support refresh tokens; and 

  7. shall provide a discovery endpoint that does not require a client certificate to authenticate using a TLS certificate that should be trusted by the user agent.

5.2.4 Confidential Client

A Confidential Client

  1. may use separate and distinct Redirect URI for each Authorization Server that it talks to; and

  2. shall accept and verify signed ID Tokens (JWS);

6. Accessing Protected Resources

6.1 Introduction

The FAPI endpoints are OAuth 2.0 protected resource endpoints that return various financial information for the resource owner associated with the submitted access token.

6.2 Access Provisions

6.2.1 Protected resources provisions

The resource server with the FAPI endpoints

  1. shall mandate mutually authenticated TLS; and

  2. shall verify that the client identifier bound to the underlying mutually authenticated TLS transport session matches the client that the access token was issued to.

6.2.2 Client Provisions

The confidential client supporting this document

  1. shall use mutually authenticated TLS;

  2. shall supply the last time the customer logged into the client as defined by FAPI clause 6.2.2.3;

  3. shall supply the customer's IP address if this data is available as defined by FAPI clause 6.2.2.4;

  4. shall supply the merchant's IP address if this data is available in the x-merchant-ip-address header, e.g., x-fapi-merchant-ip-address: 198.51.100.119; and

  5. shall supply the customer's user agent if this data is available in the x-customer-user-agent header.

7. Request Object Endpoint

7.1 Introduction

OPs:

  1. shall not support request_uri, OIDC Request Object by Reference;

  2. shall only support Request Objects passed by value as in clause 6.3 of OIDC.

8. Security Considerations

  1. The Message containment failure considerations in FAPI section 7.4 shall be followed.

8.5 TLS Considerations

  1. The TLS considerations in FAPI section 7.1 shall be followed; and

  2. The TLS considerations in FAPI-RW section 8.5 shall be followed.

8.6 JWS Algorithm Considerations

  1. The JWS algorithm considerations in FAPI-RW section 8.6 shall be followed.

NZ Client Initiated Backchannel Authentication Profile

The NZ Client Initiated Backchannel Authentication Profile extends from [FAPI: Client Initiated Backchannel Authentication Profile] FAPI-CB.

This section identifies variations from FAPI-CB and the numbered section references where there is a variation in FAPI-CB.

The Client Initiated Backchannel Authentication Flow [CIBA] specifies an alternate method of users granting access to their resources whereby the flow is started from a consumption device, but authorized on an authentication device.

Client Initiated Backchannel Authentication Variations

5.2 Read and Write API Security Provisions

5.2.2 Authorization Server

The Authorization Server

  1. shall require a previously staged ConsentId to be passed in the authentication request;

  2. shall not require clients to provide a request_context claim - as these fraud and threat parameters will be passed in the consent object;

  3. shall only support login_hint_token and id_token_hint; and 

  4. shall not support the user_code parameter in the authentication request.

6. Accessing Protected Resources

6.1 Introduction

The FAPI endpoints are OAuth 2.0 protected resource endpoints that return various financial information for the resource owner associated with the submitted access token.

6.2 Access Provisions

6.2.1 Protected resources provisions

The resource server with the FAPI endpoints

  1. shall mandate mutually authenticated TLS; and 

  2. shall verify that the client identifier bound to the underlying mutually authenticated TLS transport session matches the client that the access token was issued to.

6.2.2 Client Provisions

The confidential client supporting this document

  1. shall use mutually authenticated TLS;

  2. shall supply the last time the customer logged into the client as defined by FAPI clause 6.2.2.3;

  3. shall supply the customer's IP address if this data is available as defined by FAPI clause 6.2.2.4;

  4. shall supply the merchant's IP address if this data is available in the x-merchant-ip-address header, e.g., x-fapi-merchant-ip-address: 198.51.100.119; and 

  5. shall supply the customer's user agent if this data is available in the x-customer-user-agent header.

7. Security Considerations

7.9 TLS Considerations

  1. The TLS considerations in FAPI-CB section 7.9 shall be followed.

7.10 Algorithm Considerations

  1. The JWS algorithm considerations in FAPI-CB section 7.10 shall be followed.

Non-Normative Examples

Hybrid Flow

This section describes parameters that should be used with a hybrid grant flow request so that an ConsentId can be passed from the Third Party to an API Provider for minimum conformance for the NZ Read and Write API Security Profile (extending FAPI-RW). The hybrid flow is used as the redirect authorisation flow for the NZ Banking Data APIs.

Prior to this step, 

  1. The Third Party would have already registered a consent with an API Provider. This is achieved by creating a resource with an account information or payment consent APIs.

  2. The API Provider would have responded with an ConsentId (this is the unique identifier for the consent resource).

Authorization Request

This section describes the bare minimum set of Authorization Request parameters that an API Provider must support. The definitive reference is specified in OIDC Section 3.3.2.1 (Authentication Request) and OIDC Section 3.1.2.1 (Authentication Request)

All API Providers must support the issuance of OIDC ID Tokens, a Third Party must request that an ID Token is issued. 

This is a non-normative example of the Authorization Request:

GET /authorize? response_type=code%20id_token &client_id=s6BhdRkqt3 &state=af0ifjsldkj& &scope=openid%20payments &nonce=n-0S6_WzA2Mj &redirect_uri=https://api.mytpp.com/cb &request=eyJraWQiOiJsdGFjZXNidyIsImFsZyI6I.....JjVqsDuushgpwp0E.5leGFtcGxlIiwianRpIjoiM....JleHAiOjE0.olnx_YKAm2J1rbpOP8wGhi1BDNHJjVqsDuushgpwp0E

Parameters

Parameter

NZ Banking Data Profile

Notes

Parameter

NZ Banking Data Profile

Notes

scope

Required

Third Parties must specify the scopes that are being requested.

The scope parameter must contain openid

The scopes must be a sub-set of the scopes that were registered during Client Registration with the API Provider.

response_type

Required

OAuth 2.0 requires that this parameter is provided.

Third Parties must specify "code id_token"

The values for these parameters must match those in the Request Object, if present.

client_id

Required

Third Parties must provide this value and set it to the Client Id issued to them by the API Provider to which the authorization code grant request is being made.

redirect_uri

Required

Third Parties must provide the URI to which they want the resource owner's user agent to be redirected to after authorization.

This must be a valid, absolute URL that was registered during Client Registration with the API Provider.

state

Required

Third Parties must provide a state parameter.

The parameter may be of any format and is opaque to the API Provider.

The API Provider must play back the value in the redirect to the Third Party.

The API Provider must include the s_hash in the ID Token.

nonce

Required

Third Parties must provide a nonce parameter.

Used to help mitigate against replay attacks.

The API Provider must be replay the supplied nonce parameter in any ID Token response.

request

Required

The Third Party must provide a value for this parameter.

The Request Object parameter must contain a JWS that is signed by the Third Party.

The JWS payload must consist of a JSON object containing a Request Object as per OIDC Section 6.1.

Request Object

This section describes the Request Object which is used in the request Authorization Request parameter. The definitive reference is specified in OIDC Section 6.1 (Request Object). All standards and guidance MUST be followed as per the OIDC specification.

As per OIDC - when the Request Object is used, the OpenID Connect Request Object values (in the JWT) supersede those which are passed using the OAuth 2.0 request query parameter syntax. 

The Request Object:

  • must contain a "claims" request parameter with the ConsentId in the "id_token" object as an essential claim

  • may contain additional "claims" to be requested if the API Provider's Authorization Server support them - these claims must be listed on the OIDC Well Known configuration endpoint.

In OIDC - the "claims" request parameter in the Request Object is used to request that specific Claims be returned in either the ID Token or at the userinfo endpoint. Hence the top level members of the "claims" request parameter are:

  • id_token

  • userinfo

The userinfo and id_token members of the claims request parameter are JSON objects with the names of the individual Claims being requested as the member names. Within an individual Claims field, the "essential" field is required to indicate whether the Claim being requested is an Essential Claim. If the value is true, this indicates that the claim is an Essential Claim.

For instance, the claim request:

"claims": { "id_token": { "ConsentId": { "value": "urn-alphabank-intent-58923", "essential": true } } }

can be used to specify that it is essential to return the ConsentId as a claim in the ID Token.

This is a non-normative example of the Request Object JWS - without Base64 encoding:

{ "alg": "PS256", "kid": "GxlIiwianVqsDuushgjE0OTUxOTk" } . { "aud": "https://api.alphanbank.com", "iss": "s6BhdRkqt3", "response_type": "code id_token", "client_id": "s6BhdRkqt3", "redirect_uri": "https://api.mytpp.com/cb", "scope": "openid payments", "state": "af0ifjsldkj", "nonce": "n-0S6_WzA2Mj", "max_age": 86400, "claims": { "id_token": { "ConsentId": { "value": "urn-alphabank-intent-58923", "essential": true } } } } . <<signature>>

Claims

Where appropriate follow the JWT Good Practice Guides http://self-issued.info/docs/draft-sheffer-oauth-jwt-bcp-00.html#rfc.section.3.1 

Field

NZ Banking Data Profile

Notes

Field

NZ Banking Data Profile

Notes

aud

Required

The aud value should be or include the API Provider's Issuer Identifier URL.

iss

Required

The iss value should be the Client Id of the Third Party, unless it was signed by a different party than the Third Party.

scope

Required

Third Parties must specify the scopes that are being requested.

The scope parameter must contain openid

The scopes must be a sub-set of the scopes that were registered during Client Registration with the API Provider.

response_type

Required

Third Parties must provide this field and set its value to 'code id_token'.

The values must match those in the request parameter.

client_id

Required

Third Parties must provide this value and set it to the Client Id issued to them by the API Provider to which the authorization code grant request is being made.

redirect_uri

Required

Third Parties must provide the URI to which they want the resource owner's user agent to be redirected to after authorization.

This must be a valid, absolute URL that was registered during Client Registration with the API Provider.

state

Required

Third Parties must provide a state parameter.

The parameter may be of any format and is opaque to the API Provider.

The API Provider must play back the value in the redirect to the Third Party.

The API Provider must include the s_hash in the ID Token.

nonce

Required

Third Parties must provide a nonce parameter.

Used to help mitigate against replay attacks. 

The API Provider must be replay the supplied nonce parameter in any ID Token response.

max_age

Optional

Third Parties may provide a maximum authentication age parameter.

This specifies the allowable elapsed time in seconds since the last time the End-User was actively authenticated by the API Provider. If the elapsed time is greater than this value, the API Provider must attempt to actively re-authenticate the Customer. (The max_age request parameter corresponds to the OpenID 2.0 PAPE [OpenID.PAPE] max_auth_age request parameter.)

If the parameter is provided, the API Provider must include an auth_time Claim value in the ID Token.

claims.id_token.ConsentId

Required

Third Parties must provide a ConsentId.

The ConsentId must be the identifier for a consent resource returned by the API Provider to Third Party that is initiating the authorisation request.

ID Token

This is a non-normative example of an ID Token returned - with the sub being populated with the ConsentId.

{ "alg": "PS256", "kid": "12345", "typ": "JWT" } . { "iss": "https://api.alphabank.com", "iat": 1234569795, "auth_time": 1234569785, "sub": "urn:alphabank-intent-58923", "ConsentId": "urn:alphabank-intent-58923", "aud": "s6BhdRkqt3", "nonce": "n-0S6_WzA2Mj", "exp": 1311281970, "s_hash": "76sa5dd", "c_hash": "asd097d" } . <<signature>>

Claims

Where appropriate please follow the JWT Good Practice Guides http://self-issued.info/docs/draft-sheffer-oauth-jwt-bcp-00.html#rfc.section.3.1 

Field

NZ Banking Data Profile

Notes

Field

NZ Banking Data Profile

Notes

aud

Required

As per FAPI-RW and OIDC.

Audience that the ID Token is intended for.

OpenID Connect protocol mandates this must include the ClientID of the Third Party's OAuth Client.

iss

Required

A JSON string that represents the issuer identifier of the authorization server as defined in RFC7519. When a pure OAuth 2.0 is used, the value is the redirection URI. When OpenID Connect is used, the value is the issuer value of the authorization server.

Issuer of the token.

Token issuer will be specific to the business.

sub

Required



Token subject identifier.

A unique and non-repeating identifier for the subject.

  • The sub must be the same for an ID Token created by the Authorisation and Token endpoints during the Hybrid flow. 

  • The sub must be populated with the ConsentId.

ConsentId

Required

It's acknowledged that this field duplicates the value in "sub".

The ConsentId of the originating request.

exp

Required

The validity length will be at the discretion of the API Providers as long as it does not impact the functionality of the APIs. E.g., an expiry time of 1 second is insufficient for all resource requests

Token expiration date/time.

Expressed as an epoch i.e. number of seconds from 1970-01-01T0:0:0Z as measured in UTC. RFC7519.

iat

Required

Token issuance date/time.

Expressed as an epoch i.e. number of seconds from 1970-01-01T0:0:0Z as measured in UTC. RFC7519.

auth_time

Case-Specific

The date/time the Customer was authorised.

This field must be provided when max_age is in the Authorization Request is made or max_age is included as an essential claim. In order to be compliant with the protocol we therefore need to support it.

Expressed as an epoch i.e. number of seconds from 1970-01-01T0:0:0Z as measured in UTC. RFC7519.

nonce

Required

As per FAPI-RW (Hybrid Flow), and OIDC (Hybrid Flow).

Used to help mitigate against replay attacks.

The API Provider must be replay the supplied nonce parameter (in the Authorization Request) in any ID Token response.

c_hash

Required

Code hash value.

Its value is the base64url encoding of the left-most half of the hash of the octets of the ASCII representation of the code value, where the hash algorithm used is the hash algorithm used in the alg Header Parameter of the ID Token's JOSE Header.

s_hash

Required

State hash value.

must include state hash, s_hash, in the ID Token to protect the state value - if the state value is provided in the Authorization Request.

Its value is the base64url encoding of the left-most half of the hash of the octets of the ASCII representation of the state value, where the hash algorithm used is the hash algorithm used in the alg Header Parameter of the ID Token's JOSE Header. For instance, if the alg is HS512, hash the code value with SHA-512, then take the left-most 256 bits and base64url encode them. The s_hash value is a case sensitive string.

Decoupled Request

This section describes parameters that should be used with a decoupled flow so that a ConsentId can be passed from the Third Party to an API Provider for minimum conformance for the NZ Client Initiated Backchannel Authentication Profile (extending FAPI-CB).

Prior to this step, 

  1. The Third Party would have already registered a consent with an API Provider. This is achieved by creating a resource with an account information or payment consent APIs.

  2. The API Provider would have responded with an ConsentId (this is the unique identifier for the consent resource).

Authorization Request

This section describes the bare minimum set of Authorization Request parameters that an API Provider must support. The definitive reference is specified in CIBA Section 7.1 (Authentication Request).

As per FAPI-CB 5.2.2.6 the Authorization Requests shall be signed as per CIBA Section 7.1.1

This is a non-normative example of the Authorization Request:

POST /bc-authorize HTTP/1.1 Host: server.example.com Authorization: Bearer czZCaGRSa3F0MzpnWDFmQmF0M2JW Content-Type: application/x-www-form-urlencoded request=eyJraWQiOiJsdGFjZXNidyIsImFsZyI6IlJTMjU2In0.GasCmoMYSMohPOb nwAlkm8Yf0uglhxM83B0dj_I10vwlMGnVFvydaH9wnacM4Ln7E-JIYOxtZa33abf 1PB3fLs29GKOBmgNPn3NrxJ0iCLb0F243556Ypzdhcyj7vM8ukNzkKT3eQ0ZWJ1v VRToThgKyIN-HvLFpeSfJtSH5ycMYOjob-qXUgKpQryUbgbpqsM1XnUV-8aBD5d8 VF5fQoz0.PQWq63B_zpC22nstIFxNmfxztSFpnW0vgX0htNKOtL_HMwFRfwh71g

This is the example Request Object - without Base64 encoding:

{ "alg": "PS256", "kid": "GxlIiwianVqsDuushgjE0OTUxOTk" } . { "aud": "https://api.alphanbank.com", "iss": "s6BhdRkqt3", "nbf": 1537818886, "exp": 1537820086, "iat": 1537819486, "jti": "4LTCqACC2ESC5BWCnN3j58EnA", "client_notification_token": "8d67dc78-7faa-4d41-aabd-67707b374255", "scope": "openid payments" "ConsentId": "urn-alphabank-intent-58923", "login_hint_token": "eyJraWQiOiJsdGFjZXNidyIsImFsZyI6IlJTMjU2I n0.eyJzdWJqZWN0Ijp7InN1YmplY3RfdHlwZSI6InBob25lIiwicGhvbmUiO iIrMTMzMDI4MTgwMDQifX0.YB8_8OksJd1FwfVsIUlH-rs9cPhkIa0DUi7OV W_Da9gP6huBxf7aSDl3qKXA20uT1zThuSiYz0bdz8J_KPRHuC6vwoFlz9yBJ 9ksWOP28sHPPi19_4-xidwnb8P12-RoXwY2eAF82_NAn2vmpvqUjluoWyNHa y8vguChIutqziV0bFl-7oaxp36i4elbvT_DYeg20a0jz4wIBKc_46K8I28Er kwbI5O35GfElPXl-4J55NHkkOsDxuUYQtWjSM3wme19735XWq2DIT2nmLFi4 HzzT27W0cnJg7L_ai9uNNBvIx_Mp5AbcmkR83apR4jxnQuE5Xf23qyRpAhaw e7IPQ" } . <<signature>>

Claims

Field

NZ Banking Data Profile

Notes

Field

NZ Banking Data Profile

Notes

aud

Required

The aud value should be or include the API Provider's Issuer Identifier URL.

iss

Required

The iss value should be the Client Id of the Third Party, unless it was signed by a different party than the Third Party.

nbf

Required

The time before which the JWT must not be accepted for processing. The processing of the "nbf" claim requires that the current date/time MUST be after or equal to the not-before date/time listed in the nbf claim.

Expressed as an epoch i.e. number of seconds from 1970-01-01T0:0:0Z as measured in UTC. RFC7519.

exp

Required

Token expiration date/time.

Expressed as an epoch i.e. number of seconds from 1970-01-01T0:0:0Z as measured in UTC. RFC7519.

iat

Required

Token issuance date/time.

Expressed as an epoch i.e. number of seconds from 1970-01-01T0:0:0Z as measured in UTC. RFC7519.

jti

Required

The jti (JWT ID) claim provides a unique identifier for the JWT.

scope

Required

Third Parties must specify the scopes that are being requested.

The scope parameter must contain openid

The scopes must be a sub-set of the scopes that were registered during Client Registration with the API Provider.

ConsentId

Required

Third Parties must provide a ConsentId for which this authorisation is requested.

client_notification_token

Optional

Third Parties must provide this field if registered to use Ping mode. 

It is a bearer token provided by the Third Party that will be used by the API Provider to authenticate the callback request to the Third Party. 

login_hint_token

Optional

A token containing information identifying the Customer for whom authentication is being requested.

The particular details for the login_hint_token are documented in the NZ Banking Data API standard.

Third Parties must provide either a login_hint_token or an id_token_hint

id_token_hint

Optional

An ID Token previously issued to the Third Party by the API Provider being passed back as a hint to identify the Customer for whom authentication is being requested.

Third Parties must provide either a login_hint_token or an id_token_hint

requested_expiry

Optional

A positive integer allowing the client to request the expires_in value for the auth_req_id the server will return.

The API Provider may use this value to influence the lifetime of the authentication request and is encouraged to do so where it will improve the user experience, for example by terminating the authentication when as it knows the client is no longer interested in the result.

Login Hint Token

This is a non-normative example of a Login Hint Token - which is used to identify the Customer.

{ "alg": "PS256", "kid": "GxlIiwianVqsDuushgjE0OTUxOTk" } . { "subject": { "subject_type": "phone", "phone": "+64-220466878" } } . <<signature>>

Claims

Field

NZ Banking Data Profile

Notes

Field

NZ Banking Data Profile

Notes

subject_type

Required

Third Parties must specify the type of identification provided in the login_hint_token.

This is limited to:

  • phone

  • email

  • username

  • api_provider_token

  • third_party_token

username

Optional

The username that identifies the Customer with the API Provider.

phone

Optional

A phone number that identifies the Customer with the API Provider.

email

Optional

An email address that identifies the Customer with the API Provider.

api_provider_token

Optional

A token generated by a Customer's authentication device that identifies the Customer with the API Provider.

third_party_token

Optional

A token generated by a Third Party and registered with a Customer's authentication device by the Customer.

ID Token Hint

This ID Token must be from a previously successful authentication event for the Customer. As this is a previously used ID Token, it is valid for a Third Party to use an expired ID Token.

This is the example Request Object - without Base64 encoding - using the ID Token Hint:

{ "alg": "PS256", "kid": "GxlIiwianVqsDuushgjE0OTUxOTk" } . { "aud": "https://api.alphanbank.com", "iss": "s6BhdRkqt3", "nbf": 1537818886, "exp": 1537820086, "iat": 1537819486, "jti": "4LTCqACC2ESC5BWCnN3j58EnA", "client_notification_token": "8d67dc78-7faa-4d41-aabd-67707b374255", "scope": "openid payments" "ConsentId": "urn-alphabank-intent-58923", "id_token_hint": "eyJhbGciOiJSUzI1NiIsImtpZCI6IjE2NzcyNiJ9.eyJpc3MiOiJo dHRwczovL3NlcnZlci5leGFtcGxlLmNvbSIsInN1YiI6IjI0ODI4OTc2MTAwMSIs ImF1ZCI6InM2QmhkUmtxdDMiLCJlbWFpbCI6ImphbmVkb2VAZXhhbXBsZS5jb20i LCJleHAiOjE1Mzc4MTk4MDMsImlhdCI6MTUzNzgxOTUwM30.aVq83mdy72ddIFVJ LjlNBX-5JHbjmwK-Sn9Mir-blesfYMceIOw6u4GOrO_ZroDnnbJXNKWAg_dxVynv MHnk3uJc46feaRIL4zfHf6Anbf5_TbgMaVO8iczD16A5gNjSD7yenT5fslrrW-NU _vtmi0s1puoM4EmSaPXCR19vRJyWuStJiRHK5yc3BtBlQ2xwxH1iNP49rGAQe_LH fW1G74NY5DaPv-V23JXDNEIUTY-jT-NbbtNHAxnhNPyn8kcO2WOoeIwANO9BfLF1 EFWtjGPPMj6kDVrikec47yK86HArGvsIIwk1uExynJIv_tgZGE0eZI7MtVb2UlCw DQrVlg" } . <<signature>>

Authorization Request Response

The following is a non-normative example of an authentication response:

HTTP/1.1 200 OK Content-Type: application/json Cache-Control: no-store { "auth_req_id": "1c266114-a1be-4252-8ad1-04986c5b9ac1", "expires_in": 3600, "interval": 2 }

Claims

Field

NZ Banking Data Profile

Notes

Field

NZ Banking Data Profile

Notes

auth_req_id

Required

This is a unique identifier to identify the authentication request made by the Client. It MUST contain sufficient entropy (a minimum of 128 bits while 160 bits is recommended) to make brute force guessing or forgery of a valid auth_req_id computationally infeasible - the means of achieving this are implementation specific, with possible approaches including secure pseudorandom number generation or cryptographically secured self-contained tokens.

expires_in

Required

A JSON number with a positive integer value indicating the expiration time of the "auth_req_id" in seconds since the authentication request was received. A Client calling the token endpoint with an expired auth_req_id will receive an error.

interval

Optional

A JSON number with a positive integer value indicating the minimum amount of time in seconds that the Client MUST wait between polling requests to the token endpoint. This parameter will only be present if the Client is registered to use the Poll or Ping modes.

Token Request

The following is a non-normative example of a token request using the auth_req_id in the authorisation request response.

POST /token HTTP/1.1 Host: server.example.com Content-Type: application/x-www-form-urlencoded Authorization: Bearer czZCaGRSa3F0MzpnWDFmQmF0M2JW grant_type=urn%3Aopenid%3Aparams%3Agrant-type%3Aciba &auth_req_id=1c266114-a1be-4252-8ad1-04986c5b9ac1

Token Request Response

The following is a non-normative example of a successful token response.

HTTP/1.1 200 OK Content-Type: application/json Cache-Control: no-store { "access_token": "G5kXH2wHvUra0sHlDy1iTkDJgsgUO1bN", "token_type": "Bearer", "refresh_token": "4bwc0ESC_IAhflf-ACC_vjD_ltc11ne-8gFPfA2Kx16", "expires_in": 3600, "id_token": "eyJhbGciOiJSUzI1NiIsImtpZCI6IjE2NzcyNiJ9....eyJpc3MiOiJ dHRwczovL3NlcnZlci5leGFtcGxlLmNvbSIsInN1YiI6IjI0ODI4OTc2MTAwMSIs LCJleHAiOjE1Mzc4MTk4MDMsImlhdCI6MTUzNzgxOTUwM30....83mdy72ddIFVJ MHnk3uJc46feaRIL4zfHf6Anbf5_TbgMaVO8iczD16A5gNjSD7yenT5fslrrW-NU DQrVlg" }

Ping Callback

The following is a non-normative example of a Ping callback response. The API Provider calls POST at the Third Party's registered callback endpoint with the client_notification_token in the original Authorisation Request, and the auth_req_id in the body of the request.

POST /cb HTTP/1.1 Host: client.example.com Authorization: Bearer 8d67dc78-7faa-4d41-aabd-67707b374255 Content-Type: application/json { "auth_req_id": "1c266114-a1be-4252-8ad1-04986c5b9ac1" }

ID Token

This is a non-normative example of an ID Token returned - with the sub being populated with the ConsentId.

{ "alg": "PS256", "kid": "12345" } . { "aud": "s6BhdRkqt3", "iss": "https://api.alphabank.com", "sub": "urn:alphabank-intent-58923", "ConsentId": "urn:alphabank-intent-58923", "iat": 1234569795, "exp": 1311281970 } . <<signature>>

Claims

Where appropriate please follow the JWT Good Practice Guides http://self-issued.info/docs/draft-sheffer-oauth-jwt-bcp-00.html#rfc.section.3.1 

Field

NZ Banking Data Profile

Notes

Field

NZ Banking Data Profile

Notes

aud

Required

As per FAPI-RW and OIDC.

Audience that the ID Token is intended for.

OpenID Connect protocol mandates this must include the ClientID of the Third Party's OAuth Client.

iss

Required

A JSON string that represents the issuer identifier of the authorization server as defined in RFC7519. When a pure OAuth 2.0 is used, the value is the redirection URI. When OpenID Connect is used, the value is the issuer value of the authorization server.

Issuer of the token.

Token issuer will be specific to the business.

sub

Required



Token subject identifier.

A unique and non-repeating identifier for the subject.

  • The sub must be the same for an ID Token created by the Authorisation and Token endpoints during the Hybrid flow. 

  • The sub must be populated with the ConsentId.

ConsentId

Required

It's acknowledged that this field duplicates the value in "sub".

The ConsentId of the originating request.

exp

Required

The validity length will be at the discretion of the Banks provided that it does not impact the functionality of the APIs. For example, an expiry time of 1 second is insufficient for all Resource Requests.
 

Token expiration date/time.

Expressed as an epoch i.e. number of seconds from 1970-01-01T0:0:0Z as measured in UTC. RFC7519.

iat

Required

Token issuance date/time.

Expressed as an epoch i.e. number of seconds from 1970-01-01T0:0:0Z as measured in UTC. RFC7519.

Implementation Guide

This provides an implementation perspective of the NZ Banking Data Security Profile aligned to the accepted NZ Banking Data APIs for:

  • The Hybrid Flow (illustrated with the Payment Initiation APIs)

  • The Decoupled Flow (illustrated with the Account Information APIs)

Both the Payment Initiation APIs and the Account Information APIs rely on the same underlying consent flow - so either authorisation flow may be used for both Payment Initiation and Account Information.

Hybrid Flow

The implementation is based on the following known configurations:

Client Types