FactSet's OAuth 2.0 Guidelines

FactSet APIs use OAuth 2.0 for authentication and authorization. Public and Confidential Clients are supported, along with the Client Credentials and the Authorization Code flows. This document specifies the requirements of Client applications, and it details the flows, including the expected properties in all messages. It provides the location of the Discovery Document, containing the OAuth 2.0 URIs for the Authorization and the Token endpoints. And, with the aid of bash shell scripts in this repository, this document explains how to test.

Client Types

FactSet supports Public and Confidential OAuth 2.0 Clients.

Public Clients

Public Client applications are incapable of keeping private signing keys confidential. They include Mobile Device Native applications, desktop applications, Single-Page Applications, and IoT devices. Their resources are directly accessible, presenting an opportunity for unauthorized parties to extract embedded data objects, including private signing keys. As such, FactSet stipulates the following.

Public Clients must use Authorization Code grant type, optionally with Refresh Token.
Authorization Code grant type requires the PKCE extension to ensure that the application that initiated the flow is the same as the one which completes it. The S256 code challenge method must be used to protect against disclosure of the code verifier value.
The redirection URI provided in the Authorization Code request must exactly match one of registered URIs. FactSet's Authorization Server restricts redirection URIs to a fixed set of absolute HTTPS URIs without wildcard domains, paths, or query string components. Since the Authorization Server exclusively delivers the authorization code to an absolute registered URI, the redirection URI provided in the request serves as proof of Client application identity. Refer to OAuth 2.0 Security Best Current Practice for further details.

Confidential Clients

Confidential Client applications can securely store private signing keys, enabling them to prove identity to FactSet's Authorization Server. FactSet stipulates the following.

Confidential Clients may use Client Credentials grant type and/or Authorization Code grant type, optionally with Refresh Token.
Authorization Code grant type requires the PKCE extension to ensure that the application that initiated the flow is the same as the one which completes it. The S256 code challenge method must be used to protect against disclosure of the code verifier value.
Confidential Clients prove identity with JSON Web Signature (JWS), a.k.a. signed JSON Web Token (JWT). Before a Confidential Client participates in an OAuth 2.0 flow, the public signing keys used to authenticate the signatures of messages sent by the Client must be registered with Authentication Server via the Developer Portal.
The redirection URI provided in the Authorization Code request must exactly match one of registered URIs. FactSet's Authorization Server restricts redirection URIs to a fixed set of absolute HTTPS URIs without wildcard domains, paths, or query string components. Since the Authorization Server exclusively delivers the authorization code to an absolute registered URI, the redirection URI provided in the request serves as additional proof of Client application identity. Refer to OAuth 2.0 Security Best Current Practice for further details.

Discovery Document

The OAuth 2.0 URIs for the Authorization Endpoint and the Token Endpoint are obtainable from FactSet’s OpenID Connect Discovery Document, a JSON document located at a well-known URI that contains metadata describing the configuration of FactSet’s OpenID provider. The document can be retrieved from:

https://auth.factset.com/.well-known/openid-configuration

Below is a segment of FactSet's Discovery Document fetched at the time of this writing.

{
  issuer: "https://auth.factset.com",
  authorization_endpoint: "https://auth.factset.com/as/authorization.oauth2",
  token_endpoint: "https://auth.factset.com/as/token.oauth2",
  revocation_endpoint: "https://auth.factset.com/as/revoke_token.oauth2",
  userinfo_endpoint: "https://auth.factset.com/idp/userinfo.openid",
  introspection_endpoint: "https://auth.factset.com/as/introspect.oauth2",
  jwks_uri: "https://auth.factset.com/pf/JWKS",
  registration_endpoint: "https://auth.factset.com/as/clients.oauth2",
  ping_revoked_sris_endpoint: "https://auth.factset.com/pf-ws/rest/sessionMgmt/revokedSris",
  ping_end_session_endpoint: "https://auth.factset.com/idp/startSLO.ping",
  device_authorization_endpoint: "https://auth.factset.com/as/device_authz.oauth2",
  ...
}

The appropriately named authorization_endpoint and token_endpoint entries contain the Authorization Endpoint and Token Endpoint URIs, respectively.

For Confidential Client applications, the Audience (aud) JWS payload claim must be a single-element array containing the URI in the issuer entry.

Although the values in the Discovery Document are tentative, they will rarely if ever change. The document can be safely cached for 30 days. It does not need to be retrieved at the start of each OAuth 2.0 flow.

JSON Web Signature (JWS)

Confidential Clients authenticate with JSON Web Signature (JWS), a.k.a. signed JSON Web Token (JWT).

JWS Components

JWS consists of the following components.

JOSE Header

FactSet requires the following JOSE Header parameters.

Algorithm (alg) must be “RS256”, indicating signing with RSASSA-PKCS1-v1_5 using SHA-256.
Key ID (kid) must correspond to one of the provided or generated public keys stored by FactSet's Authorization Server during Client registration.
Type (typ) is optional. Its recommended value is “JWT”.

Example JOSE Header:

{
  "alg": "RS256",
  "kid": "ed5e11169ee24b14ba8923246afb2cd6"  
}

JWS Payload

FactSet requires the following JWS Payload claims.

Issuer (iss) and Subject (sub) must both be the Client ID provided during registration.
Issued At (iat) must be the current time in seconds since the Epoch. It is a number, not a string.
Expiration Time (exp) must be the current time plus 5 minutes in seconds since the Epoch. It is the latest time the JWS can be used to prove Client identity to the Authentication Server. The value does not correspond to the expiration time of the returned Access Token. This payload claim is a number, not a string.
Not Before (nbf) must be the current time minus 5 seconds in seconds since the Epoch. The Authentication Server will not accept the JWS before this time. A value indicating the past should ensure acceptance and 5 seconds is a margin for clock skew. This payload claim is a number, not a string.
Audience (aud) must be a single-element array containing the URI in the issuer entry of FactSet's OpenID Connect Discovery Document.
JWT ID (jti) must be unique for replay prevention. A randomly generated string produced at runtime with at least 256 bits of entropy (43 characters when Base64 encoded) is recommended.

Example JWS Payload:

{
  "iss": "9ac38f9be2b24931bb74ba355d07c445",
  "sub": "9ac38f9be2b24931bb74ba355d07c445",
  "iat": 1598994498,            
  "exp": 1598994798,
  "nbf": 1598994493,      
  "aud": [ "https://auth.factset.com" ],
  "jti": "3KqivzXvFyCYOaf5nGSuSOP0Rk2PKHKMCBFiyoxMnZY"
}

JWS Signature

FactSet requires RSASSA-PKCS1-v1_5 using SHA-256, a.k.a. RS256.

JWS Compact Serialization

A Confidential Client transmits a JWS in Compact Serialized form, a period-delimited concatenation of base64url-encodings of the JWS components. For the OAuth 2.0 flows, it is sent in a POST request body parameter.

Example JWS in Compact Serialized form:

eyJ98f8GQ789Km0LI35U63naTHiEvBoHXXTIIEHwFImxcphYY1PkKl7tMH7zPUI9jXbNJM8YPagLc5bLPjDfNvebN6.eyJ1KZXXtPVYctFFPLy1Dyyi2OjfSvScGkPwW6neJVbWxJz53YDMb8aAB4Wgany3jFrk4j4D_66SgHPxUlgDDp88scrrtjsO7WugTHsfKrGP383mzQeHw2_SQe9AAQprdRNXnwYTpPAjN9565uHIg3qxrf7tiLGK1uS5yG1KPXQ.TWeHvCfylOIYE-yF8huVj6IdlD8e1fnMENWxiK13gFuKJT8AchPMOxHpPC5jEUGOHgkG7EboBn6tBQOKzWSFZWWoa7XXJBvWRCTks3tJFBB2CG9felNSxvyh4VmHWktKAgDqnJ3zYLiTC4FjK3jiOqeUb1E5PUdCL0zR5fDuk0XibH0yfQpIEVC1HfWCKjF81ATYxQOi6vpLaAyWnX6o8VIVEfqwkLaecel6ZJZ3aAP4zPM_68MPu5HEkka0sqg9CugfVzEuhI699g4L3GRC9iBnTPPRJI1fG4_yUu1cXCE7haQnd6ywGi8jNFQlTEqyOkSkdzNK-WJpWal6Jfuliy

JWK Set (JWKS)

Before a Confidential Client participates in an OAuth 2.0 flow, the public signing keys used to verify the identity of the Client must be registered with FactSet’s Authentication Server via the Developer Portal. The Developer Portal only accepts signing keys in JWK Set (JWKS) format, a JSON document containing an array of JSON Web Key (JWK) objects. If a provided JWKS contains public-private key-pairs, the Developer Portal will transform the key-pairs into public keys prior to storage. If a JWKS is not provided, the Developer Portal will generate and return a JWKS containing a single public-private key-pair; and it will store only the generated public key.

JWK Parameters

FactSet requires the following JWK parameters.

Key Type (kty) must be “RSA” and Algorithm (alg) must be “RS256”. This is required for RSASSA-PKCS1-v1_5 using SHA-256 signing.
Public Key Use (use) must be “sig” to indicate that the JWK is for verifying and/or generating digital signatures.
Key ID (kid) must be unique within the JWKS. A JWS sent by the Client will contain a kid parameter that corresponds to the Key ID of one of the registered public keys. If the specified public key is not found, then the JWS signature cannot be verified and the request will be rejected.
Modulus and Exponent (n and e, respectively) are required for public keys.
Modulus, Exponent, Private Exponent, First Prime Factor, Second Prime Factor, First Factor CRT Exponent, Second Factor CRT Exponent, and First CRT Coefficient (n, e, d, p, q, dp, dq, and qi, respectively) are required for public-private key-pairs. The Developer Portal converts public-private key-pairs into public keys by removing all parameters except for Modulus and Exponent (n and e, respectively).

Distribution

Public-private key-pairs are capable of generating and verifying digital signatures. Whereas, public keys are limited to verifying digital signatures. Consequentially, public-private key-pairs must be kept confidential. But public keys may be freely distributed to enable recipients of signed messages to validate the identity of the sender.

Examples

When registering a Confidential Client, if a JWKS is not provided, the Developer Portal will generate and return a JWKS containing a single public-private key-pair resembling the following.

{
  "keys": [
    {
      "kty": "RSA",      
      "alg": "RS256",
      "use": "sig", 
      "kid": "ed5e11169ee24b14ba8923246afb2cd6",      
      "n": "oO2Re_MzrCqR-1rLFcmuZqf2kYmqjWQax1gYo-cWIGEDX_UIvQ4FtDRx53fPfbl_LUhwMPvYhwyy1THndatW1cwJV...",
      "e": "AQAB",
      "d": "KOT2CXd99AxFWIhz_y9nIDMil01Sh-eeXnXmnRAGMWg1wVa1R8WecXK6V0W89ogC53D3AZueJIN3lnG-DcrioCXfY...",
      "p": "8oR_A9NW0NlRw5FXvuGXJNqe9iGZCzl4CGBvE7EekXai8H3FDUh33tG8hyWLaYjcYmd080wPkhbdY3F2TbRdGl3Wg...",
      "q": "qd_kPP2HRMXJX4Wb2DC5QTrAJIGISV4SeId2-w5ZiL37Qgmr-vkax1hr6C5WmnDZOUQ4Jan6endjjl69F1GdnlOjP...",
      "dp": "0-VszTzlCAo55LSjhEa7txnF9qyYejQ2aqtHol8JpHOSHqrld5uwEOIU5ciqLQXF-b0HdGUq3axYt8C1a2OCTb1b...",
      "dq": "P0uH_F2u4CYeETR0TApjjHV6kF-fS0787OH0qDjBjZzUGNgHt5zHqI0-r6VMaYEwvxC3Jvl9tdH0S2DrbdvgMdUS...",
      "qi": "xkZDjufkne-IKamDLXjxp1CnguiZg8oSky-CXDL2WR2IEG0QEASqz-syTsJ3oE0PvdV34q01obM3WpTYocqjAi8T..."
    }
  ]
}

A JWKS can contain multiple keys. Below is an example containing 2 public-private key-pairs. Note that each key-pair has a unique kid property.

{
  "keys": [
    {
      "kty": "RSA",      
      "alg": "RS256",
      "use": "sig", 
      "kid": "ed5e11169ee24b14ba8923246afb2cd6",      
      "n": "oO2Re_MzrCqR-1rLFcmuZqf2kYmqjWQax1gYo-cWIGEDX_UIvQ4FtDRx53fPfbl_LUhwMPvYhwyy1THndatW1cwJV...",
      "e": "AQAB",
      "d": "KOT2CXd99AxFWIhz_y9nIDMil01Sh-eeXnXmnRAGMWg1wVa1R8WecXK6V0W89ogC53D3AZueJIN3lnG-DcrioCXfY...",
      "p": "8oR_A9NW0NlRw5FXvuGXJNqe9iGZCzl4CGBvE7EekXai8H3FDUh33tG8hyWLaYjcYmd080wPkhbdY3F2TbRdGl3Wg...",
      "q": "qd_kPP2HRMXJX4Wb2DC5QTrAJIGISV4SeId2-w5ZiL37Qgmr-vkax1hr6C5WmnDZOUQ4Jan6endjjl69F1GdnlOjP...",
      "dp": "0-VszTzlCAo55LSjhEa7txnF9qyYejQ2aqtHol8JpHOSHqrld5uwEOIU5ciqLQXF-b0HdGUq3axYt8C1a2OCTb1b...",
      "dq": "P0uH_F2u4CYeETR0TApjjHV6kF-fS0787OH0qDjBjZzUGNgHt5zHqI0-r6VMaYEwvxC3Jvl9tdH0S2DrbdvgMdUS...",
      "qi": "xkZDjufkne-IKamDLXjxp1CnguiZg8oSky-CXDL2WR2IEG0QEASqz-syTsJ3oE0PvdV34q01obM3WpTYocqjAi8T..."
    },
    {
      "kty": "RSA",      
      "alg": "RS256",
      "use": "sig", 
      "kid": "7b1f369480e644749f5d81ae7a18be72",      
      "n": "fu4dtNtqJKr9JlPCyRGf-2HK4xLo-J-2VG07w6gdmw2b5XQQoO2Re_MzrCqR-3rLFmmuZqy2xYmqjWtax1gYo-cWI...",
      "e": "BRDZ",
      "d": "u6lbHbR1t2urnVJ5xkoSjFrS5ZDGwSpbPb46cuz4jM2NVZ02obZcNHTxYAzuhVSkH7lTobmo_1Gi9qDyI9KOOnsRa...",
      "p": "rfBeVNu2HSuB53qKbWKpdmIaDzMpXHR9UrmiN0Nkmv5pDhkw8oR_A9NW0NlRw5FXvuGXJNqe9iGZCzl4CGBvE7Eek...",
      "q": "EslsxVUHwddDJ8PhHyYwCZ9fC49LYImiFuv7D3YwGm3cKkdKRVv223VZXE_b2zDVFzsEmGM-yVPe39kIQii2gq8wz...",
      "dp": "CTb1b5qtxZTXbtOxSUkDPgpUoCVRSvw-tMG9bBNPy_deVXIZGGRCyuw1NLLk9du6-8s8hQVUe7nvBABVcHeQgUaE...",
      "dq": "gMdUSFuxDBe58PO2L1HYlSuFHZGPc1bk0AVSpN38CjjEeV3q1b5d0ilHBOxn1ILPda710ix-uWeU3BPI2uSwECkc...",
      "qi": "Ai8TLvF1Q2mD3EDvORRhY7Pq9y6FYtUa0KP-VxfPGO4F44a0znZddJzZIR3XAI1kPsx0Rz05F1wMvwaLwz4x5ycx..."
    }
  ]
}

The public-private key-pairs above were transformed into the public keys below by deleting the private key components.

{
  "keys": [
    {
      "kty": "RSA",      
      "alg": "RS256",
      "use": "sig", 
      "kid": "ed5e11169ee24b14ba8923246afb2cd6",      
      "n": "oO2Re_MzrCqR-1rLFcmuZqf2kYmqjWQax1gYo-cWIGEDX_UIvQ4FtDRx53fPfbl_LUhwMPvYhwyy1THndatW1cwJV...",
      "e": "AQAB",
    },
    {
      "kty": "RSA",      
      "alg": "RS256",
      "use": "sig", 
      "kid": "7b1f369480e644749f5d81ae7a18be72",      
      "n": "fu4dtNtqJKr9JlPCyRGf-2HK4xLo-J-2VG07w6gdmw2b5XQQoO2Re_MzrCqR-3rLFmmuZqy2xYmqjWtax1gYo-cWI...",
      "e": "BRDZ",
    }
  ]
}

Privacy-Enhanced Mail (PEM) Keys

Privacy-Enhanced Mail (PEM) is an alternative format for storing a digital signing key. Although there is no analogue to JWKS (no PEM Set format), freely available utilities exist that can convert between JWK and PEM, with one caveat: PEM does not contain a Key ID. When converting from PEM to JWK, a Key ID must be provided.

To illustrate, below is a JWKS containing 2 public-private key-pairs.

{
  "keys": [
    {
      "kty": "RSA",      
      "alg": "RS256",
      "use": "sig", 
      "kid": "ed5e11169ee24b14ba8923246afb2cd6",      
      "n": "oO2Re_MzrCqR-1rLFcmuZqf2kYmqjWQax1gYo-cWIGEDX_UIvQ4FtDRx53fPfbl_LUhwMPvYhwyy1THndatW1cwJV...",
      "e": "AQAB",
      "d": "KOT2CXd99AxFWIhz_y9nIDMil01Sh-eeXnXmnRAGMWg1wVa1R8WecXK6V0W89ogC53D3AZueJIN3lnG-DcrioCXfY...",
      "p": "8oR_A9NW0NlRw5FXvuGXJNqe9iGZCzl4CGBvE7EekXai8H3FDUh33tG8hyWLaYjcYmd080wPkhbdY3F2TbRdGl3Wg...",
      "q": "qd_kPP2HRMXJX4Wb2DC5QTrAJIGISV4SeId2-w5ZiL37Qgmr-vkax1hr6C5WmnDZOUQ4Jan6endjjl69F1GdnlOjP...",
      "dp": "0-VszTzlCAo55LSjhEa7txnF9qyYejQ2aqtHol8JpHOSHqrld5uwEOIU5ciqLQXF-b0HdGUq3axYt8C1a2OCTb1b...",
      "dq": "P0uH_F2u4CYeETR0TApjjHV6kF-fS0787OH0qDjBjZzUGNgHt5zHqI0-r6VMaYEwvxC3Jvl9tdH0S2DrbdvgMdUS...",
      "qi": "xkZDjufkne-IKamDLXjxp1CnguiZg8oSky-CXDL2WR2IEG0QEASqz-syTsJ3oE0PvdV34q01obM3WpTYocqjAi8T..."
    },
    {
      "kty": "RSA",      
      "alg": "RS256",
      "use": "sig", 
      "kid": "7b1f369480e644749f5d81ae7a18be72",      
      "n": "fu4dtNtqJKr9JlPCyRGf-2HK4xLo-J-2VG07w6gdmw2b5XQQoO2Re_MzrCqR-3rLFmmuZqy2xYmqjWtax1gYo-cWI...",
      "e": "BRDZ",
      "d": "u6lbHbR1t2urnVJ5xkoSjFrS5ZDGwSpbPb46cuz4jM2NVZ02obZcNHTxYAzuhVSkH7lTobmo_1Gi9qDyI9KOOnsRa...",
      "p": "rfBeVNu2HSuB53qKbWKpdmIaDzMpXHR9UrmiN0Nkmv5pDhkw8oR_A9NW0NlRw5FXvuGXJNqe9iGZCzl4CGBvE7Eek...",
      "q": "EslsxVUHwddDJ8PhHyYwCZ9fC49LYImiFuv7D3YwGm3cKkdKRVv223VZXE_b2zDVFzsEmGM-yVPe39kIQii2gq8wz...",
      "dp": "CTb1b5qtxZTXbtOxSUkDPgpUoCVRSvw-tMG9bBNPy_deVXIZGGRCyuw1NLLk9du6-8s8hQVUe7nvBABVcHeQgUaE...",
      "dq": "gMdUSFuxDBe58PO2L1HYlSuFHZGPc1bk0AVSpN38CjjEeV3q1b5d0ilHBOxn1ILPda710ix-uWeU3BPI2uSwECkc...",
      "qi": "Ai8TLvF1Q2mD3EDvORRhY7Pq9y6FYtUa0KP-VxfPGO4F44a0znZddJzZIR3XAI1kPsx0Rz05F1wMvwaLwz4x5ycx..."
    }
  ]
}

An individual JWK is extracted from the keys array:

{
  "kty": "RSA",      
  "alg": "RS256",
  "use": "sig", 
  "kid": "ed5e11169ee24b14ba8923246afb2cd6",      
  "n": "oO2Re_MzrCqR-1rLFcmuZqf2kYmqjWQax1gYo-cWIGEDX_UIvQ4FtDRx53fPfbl_LUhwMPvYhwyy1THndatW1cwJV...",
  "e": "AQAB",
  "d": "KOT2CXd99AxFWIhz_y9nIDMil01Sh-eeXnXmnRAGMWg1wVa1R8WecXK6V0W89ogC53D3AZueJIN3lnG-DcrioCXfY...",
  "p": "8oR_A9NW0NlRw5FXvuGXJNqe9iGZCzl4CGBvE7EekXai8H3FDUh33tG8hyWLaYjcYmd080wPkhbdY3F2TbRdGl3Wg...",
  "q": "qd_kPP2HRMXJX4Wb2DC5QTrAJIGISV4SeId2-w5ZiL37Qgmr-vkax1hr6C5WmnDZOUQ4Jan6endjjl69F1GdnlOjP...",
  "dp": "0-VszTzlCAo55LSjhEa7txnF9qyYejQ2aqtHol8JpHOSHqrld5uwEOIU5ciqLQXF-b0HdGUq3axYt8C1a2OCTb1b...",
  "dq": "P0uH_F2u4CYeETR0TApjjHV6kF-fS0787OH0qDjBjZzUGNgHt5zHqI0-r6VMaYEwvxC3Jvl9tdH0S2DrbdvgMdUS...",
  "qi": "xkZDjufkne-IKamDLXjxp1CnguiZg8oSky-CXDL2WR2IEG0QEASqz-syTsJ3oE0PvdV34q01obM3WpTYocqjAi8T..."
}

The Key ID is stored separately because it is not preserved during conversion. In this case, the kid is ed5e11169ee24b14ba8923246afb2cd6.

Finally, the JWK is passed through any of the JWK-to-PEM converters that are readily available for download. The result appear below. Note, to keep private keys private, avoid online converters.

Since it represents an RSA key, some converters will produce a PEM with a slightly different header and trailer:

Testing OAuth 2.0

This repository contains bash shell scripts for testing the OAuth 2.0 flows. After registering a Client application in the Developer Portal, the scripts can be used to verify that the Client is setup correctly. In addition, if problems are encountered while employing an OAuth 2.0 library, the requests and responses of the scripts can be compared to the those of the library to aid in debugging.

For Confidential Clients, the scripts use OpenSSL to generate digital signatures. At the time of this writing, OpenSSL does not accept public-private key-pairs in JWKS format. However, it does accept PEM format. See the discussion above for converting JWK to PEM.

The scripts depend on jq, a command-line JSON processor. If required, download instructions are available here.

Client Credentials Flow

Client Credentials flow is suitable for machine-to-machine authentication where a specific user’s permission to access data is not required. FactSet restricts the flow to Confidential Clients; i.e., a Client sends an Access Token request directly to the Authorization Server that includes a JWS for Client identity verification.

Script Execution

The request-token-with-client-creds.sh script obtains an Access Token via Client Credentials flow. When executed at the command-line without any arguments, it outputs expected usage:

$ ./request-token-with-client-creds.sh

Usage: ./request-token-with-client-creds.sh -option1 arg1 -option2 arg2 ...

Required options:

-c Client ID
-d Discovery Document URI (a.k.a. Well-known URI)
-p PEM file containing an RSA public-private key-pair
-k Signing Key ID

Optional options:

-s Scopes (a space-delimited list surrounded by quotes)

Below is an example run that uses the following arguments.

a1fd8d65a787416781e31c43306e6bb0 is the Client ID established when the Client was registered in the Developer Portal.
https://auth.factset.com/.well-known/openid-configuration is the Discovery Document URI. The document contains the Token Endpoint URI. Although the script always downloads the document, in production code it can be cached since the endpoint URIs rarely if ever change.
./pem.txt is a file containing a public-private key-pair in PEM format. It is used to generate the signature of the JWS that is sent to the Authorization Server to prove Client identity. See the discussion above for converting JWK to PEM.
ed5e11169ee24b14ba8923246afb2cd6 is the Key ID (kid) of the JWK that was converted to PEM format.

Example run:

$ ./request-token-with-client-creds.sh -c a1fd8d65a787416781e31c43306e6bb0 -d https://auth.factset.com/.well-known/openid-configuration -p ./pem.txt -k ed5e11169ee24b14ba8923246afb2cd6

[access_token]
VjSVmCDiaejIhfTWpugSxXteXtHT

[token_type]
Bearer

[expires_in]
899

The result is an Access Token. In this case, it is an opaque Bearer Token that expires in approximately 15 minutes.

The Access Token format and the expiration time are subject to change. A Client application must treat the Access Token as opaque regardless of the actual format. And it must respect the expiration time contained in the response.

The script optionally accepts a list of scopes to constrain the degree of access granted by an Access Token. Each scope corresponds to a predefined permission type to a dataset, component, functionality, feature, etc. of a specific Protected Resource. FactSet scope names resemble URLs. Below is an example run that uses 3 arbitrarily selected scopes.

$ ./request-token-with-client-creds.sh -c a1fd8d65a787416781e31c43306e6bb0 -d https://auth.factset.com/.well-known/openid-configuration -p ./pem.txt -k ed5e11169ee24b14ba8923246afb2cd6 -s "https://api.factset.com/analytics/accounts.fullcontrol https://api.factset.com/analytics/engines.readonly https://api.factset.com/analytics/engines.vault.fullcontrol"

[access_token]
suzzoIyBVtTX5vtVoliErqistX4x

[token_type]
Bearer

[expires_in]
899

Script Internals

The script uses cURL to GET the Discovery Document. In production code, the Discovery Document can be cached since the endpoint URIs rarely if ever change.

curl -s "https://auth.factset.com/.well-known/openid-configuration"

The script pipes the result to jq to extract the Token Endpoint URI and the issuer. Next, the Client ID, the issuer, the JWK Key ID, and the private-public key-pair in PEM format are collectively used to create a JWS in Compact Serialized form that will enable the Authentication Server to verify the identity of the Client. Finally, the script uses cURL to send the JWS along with any provided scopes in a POST request for the Access Token.

curl -s -d "grant_type=client_credentials&client_assertion_type=urn:ietf:params:oauth:client-assertion-type:jwt-bearer&client_assertion=eyJ98f8GQ789Km0LI35U63naTHiEvBoHXXTIIEHwFImxcphYY1PkKl7tMH7zPUI9jXbNJM8YPagLc5bLPjDfNvebN6.eyJ1KZXXtPVYctFFPLy1Dyyi2OjfSvScGkPwW6neJVbWxJz53YDMb8aAB4Wgany3jFrk4j4D_66SgHPxUlgDDp88scrrtjsO7WugTHsfKrGP383mzQeHw2_SQe9AAQprdRNXnwYTpPAjN9565uHIg3qxrf7tiLGK1uS5yG1KPXQ.TWeHvCfylOIYE-yF8huVj6IdlD8e1fnMENWxiK13gFuKJT8AchPMOxHpPC5jEUGOHgkG7EboBn6tBQOKzWSFZWWoa7XXJBvWRCTks3tJFBB2CG9felNSxvyh4VmHWktKAgDqnJ3zYLiTC4FjK3jiOqeUb1E5PUdCL0zR5fDuk0XibH0yfQpIEVC1HfWCKjF81ATYxQOi6vpLaAyWnX6o8VIVEfqwkLaecel6ZJZ3aAP4zPM_68MPu5HEkka0sqg9CugfVzEuhI699g4L3GRC9iBnTPPRJI1fG4_yUu1cXCE7haQnd6ywGi8jNFQlTEqyOkSkdzNK-WJpWal6Jfuliy&scope=https%3A%2F%2Fapi.factset.com%2Fanalytics%2Faccounts.fullcontrol%20https%3A%2F%2Fapi.factset.com%2Fanalytics%2Fengines.vault.fullcontrol%20https%3A%2F%2Fapi.factset.com%2Fanalytics%2Flookups.readonly" -X POST "https://auth.factset.com/as/token.oauth2"

The HTTP POST will look something like the following.

POST /as/token.oauth2 HTTP/2
Host: auth.factset.com
User-Agent: curl/7.58.0
Accept: */*
Content-Length: 1044
Content-Type: application/x-www-form-urlencoded

grant_type=client_credentials
&client_assertion_type=urn:ietf:params:oauth:client-assertion-type:jwt-bearer
&client_assertion=eyJ98f8GQ789Km0LI35U63naTHiEvBoHXXTIIEHwFImxcphYY1PkKl7tMH7zPUI9jXbNJM8YPagLc5bLPjDfNvebN6.eyJ1KZXXtPVYctFFPLy1Dyyi2OjfSvScGkPwW6neJVbWxJz53YDMb8aAB4Wgany3jFrk4j4D_66SgHPxUlgDDp88scrrtjsO7WugTHsfKrGP383mzQeHw2_SQe9AAQprdRNXnwYTpPAjN9565uHIg3qxrf7tiLGK1uS5yG1KPXQ.TWeHvCfylOIYE-yF8huVj6IdlD8e1fnMENWxiK13gFuKJT8AchPMOxHpPC5jEUGOHgkG7EboBn6tBQOKzWSFZWWoa7XXJBvWRCTks3tJFBB2CG9felNSxvyh4VmHWktKAgDqnJ3zYLiTC4FjK3jiOqeUb1E5PUdCL0zR5fDuk0XibH0yfQpIEVC1HfWCKjF81ATYxQOi6vpLaAyWnX6o8VIVEfqwkLaecel6ZJZ3aAP4zPM_68MPu5HEkka0sqg9CugfVzEuhI699g4L3GRC9iBnTPPRJI1fG4_yUu1cXCE7haQnd6ywGi8jNFQlTEqyOkSkdzNK-WJpWal6Jfuliy
&scope=https%3A%2F%2Fapi.factset.com%2Fanalytics%2Faccounts.fullcontrol%20https%3A%2F%2Fapi.factset.com%2Fanalytics%2Fengines.vault.fullcontrol%20https%3A%2F%2Fapi.factset.com%2Fanalytics%2Flookups.readonly

Below is an explanation of each request body query parameter.

grant_type is client_credentials to indicate Client Credentials flow.
client_assertion_type is urn:ietf:params:oauth:client-assertion-type:jwt-bearer to indicate that the Client is authenticating with a JWT Bearer Token.
client_assertion is the generated JWS used to authenticate the Client.
scope is a URL encoded version the requested scopes.

The response is a JSON document containing an Access Token.

{
  "access_token":"qUYZRl9r5bxmPKuMlt4d6OvcQzLE",
  "token_type":"Bearer",
  "expires_in":899
}

The script pipes the response to jq to pretty-print it.

Authorization Code Flow

Authorization Code flow is used by web and native Client applications to obtain Access Tokens and Refresh Tokens after a Resource Owner authorizes access to a Protected Resource. The flow is composed of 2 distinct phases: front-channel and back-channel. During the front-channel phase, the Client application communicates indirectly with the Authorization Server by using the Resource Owner’s web browser as a proxy. During the back-channel phase, the Client application communicates directly with the Authorization Server.

Front-channel Phase

In the front-channel phase, the Client application directs the Resource Owner’s web browser to FactSet’s Authorization Endpoint. That endpoint enables the Resource Owner to log in to FactSet and to optionally grant the Client application access to specific Protected Resources. Upon completing that process, the Authorization Server issues an Authorization Code and it redirects the Resource Owner’s web browser back to the Client application.

The create-auth-code-url.sh script outputs an Authorization Code request URL that can be used to initiate an Authorization Code flow. When executed at the command-line without any arguments, it prints expected usage:

$ ./create-auth-code-url.sh

Usage: ./create-auth-code-url.sh -option1 arg1 -option2 arg2 ...

Required options:

-c Client ID
-r Redirect URI
-d Discovery Document URI (a.k.a. Well-known URI)

Optional options:

-s Scopes (a space-delimited list surrounded by quotes)

Below is an example run that uses the following arguments.

b5381c2dd75942e8a946e09a9bd06e07 is the Client ID established when the Client was registered in the Developer Portal.
https://example.com/callback is one of the redirection URIs registered in the Developer Portal. The Authorization Server will callback this URI after the Resource Owner grants or denies access to the Protected Resource. For this test, nothing needs to be setup to handle the callback.
https://auth.factset.com/.well-known/openid-configuration is the Discovery Document URI. The document contains the Authorization Endpoint URI. Although the script always downloads the document, in production code it can be cached since the endpoint URIs rarely if ever change.

Example run:

$ ./create-auth-code-url.sh -c b5381c2dd75942e8a946e09a9bd06e07 -r https://example.com/callback -d https://auth.factset.com/.well-known/openid-configuration

[PKCE Code Verifier]
NW3NxvDc7p1VS87brtYq7t2KpzyCuqLTWbRQ0vhL9jP

[Authorization Code Request URL]
https://auth.factset.com/as/authorization.oauth2?response_type=code&redirect_uri=http%3A%2F%2Fexample.com%2Fcallback&state=pTJxL4HsDzuEisphtqes5KdCJw7SMLzaPeF9ouQf9ka&code_challenge_method=S256&client_id=b5381c2dd75942e8a946e09a9bd06e07&code_challenge=o-Vrb5Jp0XPiZy0h3vs7q0bePXDzrZ_h_Qnmu0z1bZ4

In addition to the Authorization Code request URL, the script generates a Code Verifier for Proof Key for Code Exchange (PKCE), an OAuth 2.0 extension that FactSet requires when using Authorization Code flow to mitigate the threat of having the Authorization Code intercepted. The Code Verifier is a randomly generated string. The script passes it through a one-way hash based on SHA-256 (S256) to create the Code Challenge. The Code Challenge along with the name of the hashing algorithm appear as query parameters in the Authorization Code request. When making the Authorization Code request, the Authorization Server stores these values. And during the subsequent request for the tokens, the Code Verifier is presented along with the Authorization Code. The Authorization Server will reject the tokens request if the hash of the Code Verifier does not match the Code Challenge provided earlier in the Authorization Code request.

To make the query parameters easier to read, a reformatted version of the generated Authorization Code request URL follows.

https://auth.factset.com/as/authorization.oauth2
    ?response_type=code
    &redirect_uri=http%3A%2F%2Fexample.com%2Fcallback
    &state=pTJxL4HsDzuEisphtqes5KdCJw7SMLzaPeF9ouQf9ka
    &code_challenge_method=S256
    &client_id=b5381c2dd75942e8a946e09a9bd06e07
    &code_challenge=o-Vrb5Jp0XPiZy0h3vs7q0bePXDzrZ_h_Qnmu0z1bZ4

Here is a breakdown of the URL:

https://auth.factset.com/as/authorization.oauth2 is the Authorization Endpoint. It was obtained from the Discovery Document.
response_type is code to indicate that the ultimate goal of the front-channel request is to obtain an Authorization Code.
redirect_uri is URL encoded, enabling a URL to be passed as a query parameter.
state is a session ID, an arbitrary value used to maintain the session state of the Client application between the Authorization Code request and the callback to the Client. The value is echoed in a query parameter during the callback. Since the script is not a web application, it generates state for illustrative purposes only. In a production system, state also safeguards against cross-site request forgery.
code_challenge_method is the name of the hashing algorithm used to convert the PKCE Code Verifier into the PKCE Code Challenge.
client_id is the Client ID established when the Client was registered in the Developer Portal.
code_challenge is the hash of the PKCE Code Verifier.

The script optionally accepts a list of scopes to constrain the degree of access granted by an Access Token. Each scope corresponds to a predefined permission type to a dataset, component, functionality, feature, etc. of a specific Protected Resource. FactSet scope names resemble URLs. Below is an example run that uses 3 arbitrarily selected scopes.

$ ./create-auth-code-url.sh -c b5381c2dd75942e8a946e09a9bd06e07 -r https://example.com/callback -d https://auth.factset.com/.well-known/openid-configuration -s "https://api.factset.com/analytics/accounts.fullcontrol https://api.factset.com/analytics/engines.readonly https://api.factset.com/analytics/engines.vault.fullcontrol"

[PKCE Code Verifier]
5KOeF0dMrvBpwiu5gY8LvfkYvOmKVMDTF4EDqNhSx2D

[Authorization Code Request URL]
https://auth.factset.com/as/authorization.oauth2?response_type=code&redirect_uri=https%3A%2F%2Fexample.com%2Fcallback&state=MabLeOjYj0clrtNs0XPtUuTxVb869FwPDDYs7Q74Qmh&code_challenge_method=S256&client_id=b5381c2dd75942e8a946e09a9bd06e07&code_challenge=aK5KS4jX3dQMGadmn0xEltBHrELR3HJb7y5h0_K_s50&scope=https%3A%2F%2Fapi.factset.com%2Fanalytics%2Faccounts.fullcontrol%20https%3A%2F%2Fapi.factset.com%2Fanalytics%2Fengines.readonly%20https%3A%2F%2Fapi.factset.com%2Fanalytics%2Fengines.vault.fullcontrol

A reformatted version of the generated Authorization Code request URL appears below.

https://auth.factset.com/as/authorization.oauth2    
    ?response_type=code
    &redirect_uri=https%3A%2F%2Fexample.com%2Fcallback
    &state=MabLeOjYj0clrtNs0XPtUuTxVb869FwPDDYs7Q74Qmh
    &code_challenge_method=S256
    &client_id=b5381c2dd75942e8a946e09a9bd06e07
    &code_challenge=aK5KS4jX3dQMGadmn0xEltBHrELR3HJb7y5h0_K_s50
    &scope=https%3A%2F%2Fapi.factset.com%2Fanalytics%2Faccounts.fullcontrol%20https%3A%2F%2Fapi.factset.com%2Fanalytics%2Fengines.readonly%20https%3A%2F%2Fapi.factset.com%2Fanalytics%2Fengines.vault.fullcontrol

To initiate an Authorization Code flow, execute create-auth-code-url.sh and enter the generated Authorization Code request URL into the address bar of a web browser. The Authorization Server will check if the Resource Owner is logged into FactSet. If not, it will respond with the FactSet login page. Once logged in, the Authentication Server will present the consent screen, a web page that explains that the Client application is requesting access to Protected Resources. Buttons on the consent screen enable the Resource Owner to allow or deny access. It also lists the scopes specified in the request URL. The Resource Owner can narrow the list to constrain the degree of access.

Upon pressing the Allow button, the Authorization Server calls back the Client application by using the redirection URI provided in the Authorization Code request. Below is an example callback URL.

https://example.com/callback?code=KTtn33Z-mKfSpqybp-wVipLxMn_SdvOQ72dIpRq3&state=MabLeOjYj0clrtNs0XPtUuTxVb869FwPDDYs7Q74Qmh

To make the query parameters easier to read, a reformatted version of the callback URL follows.

https://example.com/callback
    ?code=KTtn33Z-mKfSpqybp-wVipLxMn_SdvOQ72dIpRq3
    &state=MabLeOjYj0clrtNs0XPtUuTxVb869FwPDDYs7Q74Qmh

Here is an explanation of each part:

https://example.com/callback is the redirect_uri provided in the Authorization Code request. Redirection URIs must be registered with the Authorization Server through the Developer Portal before using Authorization Code flows.
code is the issued Authorization Code. In the back-channel phase, the Authorization Code together with the PKCE Code Verifier will be exchanged for an Access Token and possibly a Refresh Token.
state is the state value provided in the Authorization Code request. It is a session ID, an arbitrary value used to maintain the session state of the Client application between the Authorization Code request and the callback to the Client.

If the Resource Owner presses the Deny button on the consent screen, the Authorization Server notifies the Client through a callback with different query parameter. An example follows.

https://example.com/callback?error_description=User+Denied+Authorization&state=MabLeOjYj0clrtNs0XPtUuTxVb869FwPDDYs7Q74Qmh&error=access_denied#.

A reformatted version of the denied callback appears below.

https://example.com/callback
    ?error_description=User+Denied+Authorization
    &state=MabLeOjYj0clrtNs0XPtUuTxVb869FwPDDYs7Q74Qmh
    &error=access_denied
    #.

A full list of error codes is available here.

Back-channel Phase

In the back-channel phase, the Client application communicates directly with the Authorization Server to exchange the Authorization Code along with the PKCE Code Verifier for an Access Token and possibly a Refresh Token.

Script Execution

The request-tokens-with-auth-code.sh script performs the exchange. When executed at the command-line without any arguments, it prints expected usage:

$ ./request-tokens-with-auth-code.sh

Usage: ./request-tokens-with-auth-code.sh -option1 arg1 -option2 arg2 ...

Required options:

-c Client ID
-r Redirect URI
-d Discovery Document URI (a.k.a. Well-known URI)
-o Authorization Code
-v PKCE Code Verifier

For Confidential Clients:

-p PEM file containing an RSA public-private key-pair
-k Signing Key ID

request-tokens-with-auth-code.sh works in concert with create-auth-code-url.sh. Below, the create-auth-code-url.sh script is executed to generate a PKCE Code Verifier and an Authorization Code request URL.

$ ./create-auth-code-url.sh -c b5381c2dd75942e8a946e09a9bd06e07 -r https://example.com/callback -d https://auth.factset.com/.well-known/openid-configuration -s "https://api.factset.com/analytics/lookups.spar.readonly https://api.factset.com/analytics/lookups.vault.readonly"

[PKCE Code Verifier]
h3F8ZdWbzsYjhp5VIgBDbNINxwn3MbManK5q3r5Fs0W

[Authorization Code Request URL]
https://auth.factset.com/as/authorization.oauth2?response_type=code&redirect_uri=http%3A%2F%2Fexample.com%2Fcallback&state=Hp6nvinUy9owh0tbwycAZZUB9n30MwjlP7IMviduYWr&code_challenge_method=S256&client_id=b5381c2dd75942e8a946e09a9bd06e07&code_challenge=Q2PTE9StR-AY1YDEmscFIws0fPsxjs4mIjLu961SVDM&scope=https%3A%2F%2Fapi.factset.com%2Fanalytics%2Flookups.spar.readonly%20https%3A%2F%2Fapi.factset.com%2Fanalytics%2Flookups.vault.readonly

The Authorization Code request URL is entered into the address bar of a web browser, which brings up the FactSet login page, followed by the consent screen. Pressing the Allow button yields the following callback URL.

https://example.com/callback?code=jTSirkmEz_iEcn-qa0Jz6TrIWXF5LgS7PNpMQTpg&state=Hp6nvinUy9owh0tbwycAZZUB9n30MwjlP7IMviduYWr

That completes the front-channel phase.

Below, the request-tokens-with-auth-code.sh script is executed with the following arguments.

b5381c2dd75942e8a946e09a9bd06e07 is the Client ID specified in the Authorization Code request.
https://example.com/callback is the redirection URI specified in the Authorization Code request.
https://auth.factset.com/.well-known/openid-configuration is the Discovery Document URI. The document contains the Token Endpoint URI. Although the script always downloads the document, in production code it can be cached since the endpoint URIs rarely if ever change.
jTSirkmEz_iEcn-qa0Jz6TrIWXF5LgS7PNpMQTpg is the Authorization Code returned as a query parameter in the callback URL. It can be copied directly out of the address bar of the web browser.
h3F8ZdWbzsYjhp5VIgBDbNINxwn3MbManK5q3r5Fs0W is the PKCE Code Verifier output by the create-auth-code-url.sh script.

This is a test of a Confidential Client, which required the following additional arguments.

./pem.txt is a file containing a public-private key-pair in PEM format. It is used to generate the signature of the JWS that is sent to the Authorization Server to prove Client identity. See the discussion above for converting JWK to PEM.
ed5e11169ee24b14ba8923246afb2cd6 is the Key ID (kid) of the JWK that was converted to PEM format.

Example run:

$ ./request-tokens-with-auth-code.sh -c b5381c2dd75942e8a946e09a9bd06e07 -r https://example.com/callback -d https://auth.factset.com/.well-known/openid-configuration -o jTSirkmEz_iEcn-qa0Jz6TrIWXF5LgS7PNpMQTpg -v h3F8ZdWbzsYjhp5VIgBDbNINxwn3MbManK5q3r5Fs0W -p ./pem.txt -k ed5e11169ee24b14ba8923246afb2cd6

[access_token]
7svQJUfwYzeDMDkrv8C8QroaLtpM

[refresh_token]
YQCeT84qiH7zPUI9jxbNRM8rPWgY85b1PjDfNwrbN3

[token_type]
Bearer

[expires_in]
899

The result is an Access Token and a Refresh Token. In this case, the Access Token is an opaque Bearer Token that expires in approximately 15 minutes.

The Access Token format and the expiration time are subject to change. A Client application must treat the Access Token as opaque regardless of the actual format. And it must respect the expiration time contained in the response.

The response may not include a Refresh Token.

If the Resource Owner narrows the requested scopes on the consent screen, the back-channel response includes a scope property containing the approved permissions, as demonstrated below.

$ ./request-tokens-with-auth-code.sh -c b5381c2dd75942e8a946e09a9bd06e07 -r https://example.com/callback -d https://auth.factset.com/.well-known/openid-configuration -o UXNcmBpfXUFALHpAk0Lkh9M6Dx4dcWTdJGYqzU8u -v VBNoSgwIE50LlaCCaYHdhvs1rBf5AuK7PUWGOHxELtc -p ./pem.txt -k ed5e11169ee24b14ba8923246afb2cd6

[access_token]
v8XBpZhY3RzZXWuBzOzY29wSpHj4

[refresh_token]
bW03Erc3rIlLtpZCIcLD82Rr1T1uRE2IBWHmEzNfRo

[scope]
https://api.factset.com/analytics/engines.fullcontrol https://api.factset.com/analytics/lookups.spar.readonly

[token_type]
Bearer

[expires_in]
899

If the Resource Owner removes all scopes, the response includes an empty scope property:

$ ./request-tokens-with-auth-code.sh -c b5381c2dd75942e8a946e09a9bd06e07 -r https://example.com/callback -d https://auth.factset.com/.well-known/openid-configuration -o UXNcmBpfXUFALHpAk0Lkh9M6Dx4dcWTdJGYqzU8u -v VBNoSgwIE50LlaCCaYHdhvs1rBf5AuK7PUWGOHxELtc -p ./pem.txt -k ed5e11169ee24b14ba8923246afb2cd6

[access_token]
v8XBpZhY3RzZXWuBzOzY29wSpHj4

[refresh_token]
bW03Erc3rIlLtpZCIcLD82Rr1T1uRE2IBWHmEzNfRo

[scope]


[token_type]
Bearer

[expires_in]
899

create-auth-code-url.sh and request-tokens-with-auth-code.sh must be run with the proper arguments within a 5-minute window to successfully complete an Authorization Code flow. Missing the window results in an error like the one below.

$ ./request-tokens-with-auth-code.sh -c b5381c2dd75942e8a946e09a9bd06e07 -r https://example.com/callback -d https://auth.factset.com/.well-known/openid-configuration -o jTSirkmEz_iEcn-qa0Jz6TrIWXF5LgS7PNpMQTpg -v h3F8ZdWbzsYjhp5VIgBDbNINxwn3MbManK5q3r5Fs0W -p ./pem.txt -k ed5e11169ee24b14ba8923246afb2cd6

[error_description]
Authorization code is invalid or expired.

[error]
invalid_grant

A full list of error responses is available here.

Script Internals

The script uses cURL to GET the Discovery Document. In production code, the Discovery Document can be cached since the endpoint URIs rarely if ever change.

curl -s "https://auth.factset.com/.well-known/openid-configuration"

The script pipes the result to jq to extract the Token Endpoint URI and the issuer.

Public Clients POST Request

For Public Clients, the script uses cURL to send a POST request for tokens.

curl -s -d "grant_type=authorization_code&redirect_uri=https%3A%2F%2Fexample.com%2Fcallback&code=zWjtH4GZCXXapAyh-w8-t1-Ir_W1wE8kUuxIpRq0&code_verifier=UnhWMp3ZEJv4zGPVkeG2XzLs4kiwQGapLKaKXRKUJt0&client_id=c818c4a2-9fa8-4d8b-9e41-0dad859cbf4a" -X POST "https://auth.factset.com/as/token.oauth2"

The HTTP POST will look something like the following.

POST /as/token.oauth2 HTTP/2
Host: auth.factset.com
User-Agent: curl/7.58.0
Accept: */*
Content-Length: 574
Content-Type: application/x-www-form-urlencoded

grant_type=authorization_code
&redirect_uri=https%3A%2F%2Fexample.com%2Fcallback
&code=zWjtH4GZCXXapAyh-w8-t1-Ir_W1wE8kUuxIpRq0
&code_verifier=UnhWMp3ZEJv4zGPVkeG2XzLs4kiwQGapLKaKXRKUJt0
&client_id=c818c4a2-9fa8-4d8b-9e41-0dad859cbf4a

Below is an explanation of each request body query parameter.

grant_type is authorization_code to indicate a request to exchange an Authorization Code for tokens.
redirect_uri is the redirection URI specified in the front-channel phase.
code is the Authorization Code returned as a query parameter in the front-channel callback URL.
code_verifier is the PKCE Code Verifier output by the create-auth-code-url.sh script.
client_id is the Client ID specified in the front-channel phase.

Public Clients are not authenticated; no assertion is provided in the request.

Confidential Clients POST Request

For Confidential Clients, the Client ID, the issuer, the JWK Key ID, and the private-public key-pair in PEM format are collectively used to create a JWS in Compact Serialized form that will enable the Authentication Server to verify the identity of the Client. The script uses cURL to send the JWS in a POST request for tokens.

curl -s -d "grant_type=authorization_code&redirect_uri=http%3A%2F%2Fexample.com%2Fcallback&code=pvzJTd9RJWz0E0P5SYySJt4vsQhVqSbMABQqzU8u&code_verifier=RAJN72nzPlHJsjxiu4AMFdub1noCN9SeazI3JwEQRL3&client_assertion_type=urn:ietf:params:oauth:client-assertion-type:jwt-bearer&client_assertion=eyJ98f8GQ789Km0LI35U63naTHiEvBoHXXTIIEHwFImxcphYY1PkKl7tMH7zPUI9jXbNJM8YPagLc5bLPjDfNvebN6.eyJ1KZXXtPVYctFFPLy1Dyyi2OjfSvScGkPwW6neJVbWxJz53YDMb8aAB4Wgany3jFrk4j4D_66SgHPxUlgDDp88scrrtjsO7WugTHsfKrGP383mzQeHw2_SQe9AAQprdRNXnwYTpPAjN9565uHIg3qxrf7tiLGK1uS5yG1KPXQ.TWeHvCfylOIYE-yF8huVj6IdlD8e1fnMENWxiK13gFuKJT8AchPMOxHpPC5jEUGOHgkG7EboBn6tBQOKzWSFZWWoa7XXJBvWRCTks3tJFBB2CG9felNSxvyh4VmHWktKAgDqnJ3zYLiTC4FjK3jiOqeUb1E5PUdCL0zR5fDuk0XibH0yfQpIEVC1HfWCKjF81ATYxQOi6vpLaAyWnX6o8VIVEfqwkLaecel6ZJZ3aAP4zPM_68MPu5HEkka0sqg9CugfVzEuhI699g4L3GRC9iBnTPPRJI1fG4_yUu1cXCE7haQnd6ywGi8jNFQlTEqyOkSkdzNK-WJpWal6Jfuliy" -X POST "https://auth.factset.com/as/token.oauth2"

The HTTP POST will look something like the following.

POST /as/token.oauth2 HTTP/2
Host: auth.factset.com
User-Agent: curl/7.58.0
Accept: */*
Content-Length: 1044
Content-Type: application/x-www-form-urlencoded

grant_type=authorization_code
&redirect_uri=http%3A%2F%2Fexample.com%2Fcallback
&code=pvzJTd9RJWz0E0P5SYySJt4vsQhVqSbMABQqzU8u
&code_verifier=RAJN72nzPlHJsjxiu4AMFdub1noCN9SeazI3JwEQRL3
&client_assertion_type=urn:ietf:params:oauth:client-assertion-type:jwt-bearer
&client_assertion=eyJ98f8GQ789Km0LI35U63naTHiEvBoHXXTIIEHwFImxcphYY1PkKl7tMH7zPUI9jXbNJM8YPagLc5bLPjDfNvebN6.eyJ1KZXXtPVYctFFPLy1Dyyi2OjfSvScGkPwW6neJVbWxJz53YDMb8aAB4Wgany3jFrk4j4D_66SgHPxUlgDDp88scrrtjsO7WugTHsfKrGP383mzQeHw2_SQe9AAQprdRNXnwYTpPAjN9565uHIg3qxrf7tiLGK1uS5yG1KPXQ.TWeHvCfylOIYE-yF8huVj6IdlD8e1fnMENWxiK13gFuKJT8AchPMOxHpPC5jEUGOHgkG7EboBn6tBQOKzWSFZWWoa7XXJBvWRCTks3tJFBB2CG9felNSxvyh4VmHWktKAgDqnJ3zYLiTC4FjK3jiOqeUb1E5PUdCL0zR5fDuk0XibH0yfQpIEVC1HfWCKjF81ATYxQOi6vpLaAyWnX6o8VIVEfqwkLaecel6ZJZ3aAP4zPM_68MPu5HEkka0sqg9CugfVzEuhI699g4L3GRC9iBnTPPRJI1fG4_yUu1cXCE7haQnd6ywGi8jNFQlTEqyOkSkdzNK-WJpWal6Jfuliy

Below is an explanation of each request body query parameter.

grant_type is authorization_code to indicate a request to exchange an Authorization Code for tokens.
redirect_uri is the redirection URI specified in the front-channel phase.
code is the Authorization Code returned as a query parameter in the front-channel callback URL.
code_verifier is the PKCE Code Verifier output by the create-auth-code-url.sh script.
client_assertion_type is urn:ietf:params:oauth:client-assertion-type:jwt-bearer to indicate that the Client is authenticating with a JWT Bearer Token.
client_assertion is the generated JWS used to authenticate the Client.

POST Response

The POST response is a JSON document containing an Access Token and possibly a Refresh Token, depending on how the Client was registered.

{
  "access_token":"f8GQ789Km0LI35U63naTHiEvBoHX",
  "refresh_token":"YQCeT84qiH7zPUI9jxbNRM8rPWgY85b1PjDfNwrbN3",
  "token_type":"Bearer",
  "expires_in":899
}

The script pipes the response to jq to pretty-print it.

Refresh Tokens

Refresh Tokens are opaque tokens that function as credentials. They enable the Client application to request new Access Tokens directly from the Authorization Server without prompting the Resource Owner to log into FactSet and to grant permissions again. Refresh Tokens are typically used when a cached Access Token expires or otherwise becomes invalid. But they can be used at any time to obtain additional Access Tokens with the same or reduced scope. The process of issuing new Access Tokens does not expire old ones.

Script Execution

The request-tokens-with-refresh-token.sh script obtains a new Access Token from the Authorization Server by presenting a Refresh Token. When executed at the command-line without any arguments, it prints expected usage:

$ ./request-tokens-with-refresh-token.sh

Usage: ./request-tokens-with-refresh-token.sh -option1 arg1 -option2 arg2 ...

Required options:

-c Client ID
-r Redirect URI
-d Discovery Document URI (a.k.a. Well-known URI)
-t Refresh Token

For Confidential Clients:

-p PEM file containing an RSA public-private key-pair
-k Signing Key ID

Optional options:

-s Scopes (a space-delimited list surrounded by quotes)

request-tokens-with-refresh-token.sh works in concert with create-auth-code-url.sh and request-tokens-with-auth-code.sh. Below, the create-auth-code-url.sh script is executed with 3 arbitrarily selected scopes to generate a PKCE Code Verifier and an Authorization Code request URL.

$ ./create-auth-code-url.sh -c d2228aeb8e434fcaad9d77309b9bebf5 -r https://example.com/callback -d https://auth.factset.com/.well-known/openid-configuration -s "https://api.factset.com/analytics/lookups.spar.readonly https://api.factset.com/analytics/engines.pub.fullcontrol https://api.factset.com/analytics/lookups.vault.readonly"

[PKCE Code Verifier]
Msvp2UQGOwN2hTE3iFR9Ul479jssKk1lFsSAz0P5ZdS

[Authorization Code Request URL]
https://auth.factset.com/as/authorization.oauth2&response_type=code&redirect_uri=https%3A%2F%2Fexample.com%2Fcallback&state=fNkV9OHtj0oylwsEZ9RYbngAxwHgEe0Q3djTDEwOHDx&code_challenge_method=S256&client_id=d2228aeb8e434fcaad9d77309b9bebf5&code_challenge=rL6rrQPjLNTvvkbQEa94PNVIFMpxz8WNfthtaO8RSm0&scope=https%3A%2F%2Fapi.factset.com%2Fanalytics%2Flookups.spar.readonly%20https%3A%2F%2Fapi.factset.com%2Fanalytics%2Fengines.pub.fullcontrol%20https%3A%2F%2Fapi.factset.com%2Fanalytics%2Flookups.vault.readonly

The Authorization Code request URL is entered into the address bar of a web browser, which brings up the FactSet login page, followed by the consent screen. Pressing the Allow button yields the following callback URL.

https://example.com/callback?code=gCjbfsbc9x7glnFUTyVb4wnZZXxrESnaFOEqzU8u&state=fNkV9OHtj0oylwsEZ9RYbngAxwHgEe0Q3djTDEwOHDx

That completes the front-channel phase of an Authorization Code flow. Below, the request-tokens-with-auth-code.sh script is employed to carry out the back-channel phase. The PEM filename and Key ID arguments indicate that this is a test for a Confidential Client.

$ ./request-tokens-with-auth-code.sh -c d2228aeb8e434fcaad9d77309b9bebf5 -r https://example.com/callback -d https://auth.factset.com/.well-known/openid-configuration -o gCjbfsbc9x7glnFUTyVb4wnZZXxrESnaFOEqzU8u -v Msvp2UQGOwN2hTE3iFR9Ul479jssKk1lFsSAz0P5ZdS -p ./pem.txt -k ed5e11169ee24b14ba8923246afb2cd6

[access_token]
dl94d6OvcQzLEqUYZR5qxmPKuMlt

[refresh_token]
r3cd5czUdE8szHxXLICTmXBfqtHKQUsyMw6Rtp3ai

[token_type]
Bearer

[expires_in]
899

The back-channel phase obtains an Access Token and a Refresh Token. Note, depending on how the Client was registered with the Developer Portal, Authorization Code flow may not provide a Refresh Token.

Below, the request-tokens-with-refresh-token.sh script is executed with the following arguments.

d2228aeb8e434fcaad9d77309b9bebf5 is the Client ID used in the Authorization Code flow.
https://example.com/callback is the redirection URI used in the Authorization Code flow.
https://auth.factset.com/.well-known/openid-configuration is the Discovery Document URI. The document contains the Token Endpoint URI. Although the script always downloads the document, in production code it can be cached since the endpoint URIs rarely if ever change.
r3cd5czUdE8szHxXLICTmXBfqtHKQUsyMw6Rtp3ai is the Refresh Token output by the request-tokens-with-auth-code.sh script during the Authorization Code flow back-channel phase.

This is a test of a Confidential Client, which required the following additional arguments.

./pem.txt is a file containing a public-private key-pair in PEM format. It is used to generate the signature of the JWS that is sent to the Authorization Server to prove Client identity. See the discussion above for converting JWK to PEM.
ed5e11169ee24b14ba8923246afb2cd6 is the Key ID (kid) of the JWK that was converted to PEM format.

Example run:

$ ./request-tokens-with-refresh-token.sh -c d2228aeb8e434fcaad9d77309b9bebf5 -r https://example.com/callback -d https://auth.factset.com/.well-known/openid-configuration -t r3cd5czUdE8szHxXLICTmXBfqtHKQUsyMw6Rtp3ai -p ./pem.txt -k ed5e11169ee24b14ba8923246afb2cd6

[access_token]
rif6giVTkMDplgMV8w5eUXyup1zU

[token_type]
Bearer

[expires_in]
899

The result is a new Access Token. In this case, it is an opaque Bearer Token that expires in approximately 15 minutes.

The Access Token format and the expiration time are subject to change. A Client application must treat the Access Token as opaque regardless of the actual format. And it must respect the expiration time contained in the response.

If the Refresh Token is more than 24 hours old, using it will return a new Access Token plus a new Refresh Token, as demonstrated below.

$ ./request-tokens-with-refresh-token.sh -c d2228aeb8e434fcaad9d77309b9bebf5 -r https://example.com/callback -d https://auth.factset.com/.well-known/openid-configuration -t r3cd5czUdE8szHxXLICTmXBfqtHKQUsyMw6Rtp3ai -p ./pem.txt -k ed5e11169ee24b14ba8923246afb2cd6

[access_token]
WJ5qgyUiIwBhjC9iHBmfU3tDLW29

[refresh_token]
uk0XibHWOi6vp0yfQXfW5KjF81ATYxpIEvC3LaAyk

[token_type]
Bearer

[expires_in]
899

Issuing a new Refresh Token expires the old one. The following examples proves this by attempting to use the original.

$ ./request-tokens-with-refresh-token.sh -c d2228aeb8e434fcaad9d77309b9bebf5 -r https://example.com/callback -d https://auth.factset.com/.well-known/openid-configuration -t r3cd5czUdE8szHxXLICTmXBfqtHKQUsyMw6Rtp3ai -p ./pem.txt -k ed5e11169ee24b14ba8923246afb2cd6

[error_description]
unknown, invalid, or expired refresh token

[error]
invalid_grant

Other events can result in a similar error message:

The Resource Owner can rescind permissions granted to a Client at any time.
Refresh Tokens automatically expire after 30 days of disuse.
Refresh Tokens may be exchanged for new Access Tokens and new Refresh Tokens for up to a year. After that, the Client must initiate an Authorization Code flow, prompting the Resource Owner to log into FactSet and to grant permissions again.
The Authorization Server indexes Refresh Tokens using the triplet (Client ID, Resource Owner ID, granted permissions) as the key. If an Authorization Code flow is repeated for the same triplet, the existing Refresh Token will be invalidated.

When presenting a Refresh Token, if no scopes are specified, the new Access Token will bear the same permissions as the one issued during the Authorization Code flow. However, as shown below, scopes can be provided in the request to diminish the granted permissions. In this case, the list has been narrowed to a single scope.

$ ./request-tokens-with-refresh-token.sh -c d2228aeb8e434fcaad9d77309b9bebf5 -r https://example.com/callback -d https://auth.factset.com/.well-known/openid-configuration -t uk0XibHWOi6vp0yfQXfW5KjF81ATYxpIEvC3LaAyk -p ./pem.txt -k ed5e11169ee24b14ba8923246afb2cd6 -s "https://api.factset.com/analytics/lookups.spar.readonly"

[access_token]
ou0ChNEgmfgBHGsb2dL4sodT9plC

[token_type]
Bearer

[expires_in]
899

To remove all scopes, set the list to a single space:

$ ./request-tokens-with-refresh-token.sh -c d2228aeb8e434fcaad9d77309b9bebf5 -r https://example.com/callback -d https://auth.factset.com/.well-known/openid-configuration -t uk0XibHWOi6vp0yfQXfW5KjF81ATYxpIEvC3LaAyk -p ./pem.txt -k ed5e11169ee24b14ba8923246afb2cd6 -s " "

[access_token]
ou0ChNEgmfgBHGsb2dL4sodT9plC

[token_type]
Bearer

[expires_in]
899

In the following example, an attempt is made to widen the scopes list.

$ ./request-tokens-with-refresh-token.sh -c d2228aeb8e434fcaad9d77309b9bebf5 -r https://example.com/callback -d https://auth.factset.com/.well-known/openid-configuration -t uk0XibHWOi6vp0yfQXfW5KjF81ATYxpIEvC3LaAyk -p ./pem.txt -k ed5e11169ee24b14ba8923246afb2cd6 -s "https://api.factset.com/analytics/accounts.fullcontrol https://api.factset.com/analytics/engines.fullcontrol https://api.factset.com/analytics/engines.vault.fullcontrol https://api.factset.com/analytics/lookups.spar.readonly"

[error]
invalid_scope

Script Internals

The script uses cURL to GET the Discovery Document. In production code, the Discovery Document can be cached since the endpoint URIs rarely if ever change.

curl -s "https://auth.factset.com/.well-known/openid-configuration"

The script pipes the result to jq to extract the Token Endpoint URI and the issuer.

Public Clients POST Request

For Public Clients, the script uses cURL to send a POST request to the Token Endpoint.

curl -s -d "grant_type=refresh_token&redirect_uri=https%3A%2F%2Fexample.com%2Fcallback&refresh_token=gt8kJ2L2GLUlWxnFpAO3OJyCtZ3hmWLBgu24mA6wks&client_id=d2228aeb8e434fcaad9d77309b9bebf5" -X POST "https://auth.factset.com/as/token.oauth2"

The HTTP POST will look something like the following.

POST /as/token.oauth2 HTTP/2
Host: auth.factset.com
User-Agent: curl/7.58.0
Accept: */*
Content-Length: 862
Content-Type: application/x-www-form-urlencoded

grant_type=refresh_token
&redirect_uri=https%3A%2F%2Fexample.com%2Fcallback
&refresh_token=gt8kJ2L2GLUlWxnFpAO3OJyCtZ3hmWLBgu24mA6wks
&client_id=d2228aeb8e434fcaad9d77309b9bebf5

Below is an explanation of each request body query parameter.

grant_type is refresh_token to indicate a request for a new Access Token by submission of a Refresh Token.
redirect_uri is the redirection URI used in the Authorization Code flow.
refresh_token is the latest Refresh Token issued to the Client application.
client_id is the Client ID used in the Authorization Code flow.

Confidential Clients POST Request

For Confidential Clients, the Client ID, the issuer, the JWK Key ID, and the private-public key-pair in PEM format are collectively used to create a JWS in Compact Serialized form that will enable the Authentication Server to verify the identity of the Client. The script uses cURL to send the JWS in a POST request for tokens.

curl -s -d "grant_type=refresh_token&redirect_uri=https%3A%2F%2Fexample.com%2Fcallback&refresh_token=ZDMS5K5zUdE8szHxXLICTmXBfzThKQUsyyw6RtpbaC&client_assertion_type=urn:ietf:params:oauth:client-assertion-type:jwt-bearer&client_assertion=eyJ98f8GQ789Km0LI35U63naTHiEvBoHXXTIIEHwFImxcphYY1PkKl7tMH7zPUI9jXbNJM8YPagLc5bLPjDfNvebN6.eyJ1KZXXtPVYctFFPLy1Dyyi2OjfSvScGkPwW6neJVbWxJz53YDMb8aAB4Wgany3jFrk4j4D_66SgHPxUlgDDp88scrrtjsO7WugTHsfKrGP383mzQeHw2_SQe9AAQprdRNXnwYTpPAjN9565uHIg3qxrf7tiLGK1uS5yG1KPXQ.TWeHvCfylOIYE-yF8huVj6IdlD8e1fnMENWxiK13gFuKJT8AchPMOxHpPC5jEUGOHgkG7EboBn6tBQOKzWSFZWWoa7XXJBvWRCTks3tJFBB2CG9felNSxvyh4VmHWktKAgDqnJ3zYLiTC4FjK3jiOqeUb1E5PUdCL0zR5fDuk0XibH0yfQpIEVC1HfWCKjF81ATYxQOi6vpLaAyWnX6o8VIVEfqwkLaecel6ZJZ3aAP4zPM_68MPu5HEkka0sqg9CugfVzEuhI699g4L3GRC9iBnTPPRJI1fG4_yUu1cXCE7haQnd6ywGi8jNFQlTEqyOkSkdzNK-WJpWal6Jfuliy"  -X POST "https://auth.factset.com/as/token.oauth2"

The HTTP POST will look something like the following.

POST /as/token.oauth2 HTTP/2
Host: auth.factset.com
User-Agent: curl/7.58.0
Accept: */*
Content-Length: 1044
Content-Type: application/x-www-form-urlencoded

grant_type=refresh_token
&redirect_uri=https%3A%2F%2Fexample.com%2Fcallback
&refresh_token=ZDMS5K5zUdE8szHxXLICTmXBfzThKQUsyyw6RtpbaC
&client_assertion_type=urn:ietf:params:oauth:client-assertion-type:jwt-bearer
&client_assertion=eyJ98f8GQ789Km0LI35U63naTHiEvBoHXXTIIEHwFImxcphYY1PkKl7tMH7zPUI9jXbNJM8YPagLc5bLPjDfNvebN6.eyJ1KZXXtPVYctFFPLy1Dyyi2OjfSvScGkPwW6neJVbWxJz53YDMb8aAB4Wgany3jFrk4j4D_66SgHPxUlgDDp88scrrtjsO7WugTHsfKrGP383mzQeHw2_SQe9AAQprdRNXnwYTpPAjN9565uHIg3qxrf7tiLGK1uS5yG1KPXQ.TWeHvCfylOIYE-yF8huVj6IdlD8e1fnMENWxiK13gFuKJT8AchPMOxHpPC5jEUGOHgkG7EboBn6tBQOKzWSFZWWoa7XXJBvWRCTks3tJFBB2CG9felNSxvyh4VmHWktKAgDqnJ3zYLiTC4FjK3jiOqeUb1E5PUdCL0zR5fDuk0XibH0yfQpIEVC1HfWCKjF81ATYxQOi6vpLaAyWnX6o8VIVEfqwkLaecel6ZJZ3aAP4zPM_68MPu5HEkka0sqg9CugfVzEuhI699g4L3GRC9iBnTPPRJI1fG4_yUu1cXCE7haQnd6ywGi8jNFQlTEqyOkSkdzNK-WJpWal6Jfuliy

Below is an explanation of each request body query parameter.

grant_type is refresh_token to indicate a request for a new Access Token by submission of a Refresh Token.
redirect_uri is the redirection URI used in the Authorization Code flow.
refresh_token is the latest Refresh Token issued to the Client application.
client_assertion_type is urn:ietf:params:oauth:client-assertion-type:jwt-bearer to indicate that the Client is authenticating with a JWT Bearer Token.
client_assertion is the generated JWS used to authenticate the Client.

POST Response

The POST response is a JSON document containing a newly issued Access Token.

{
  "access_token":"cPucQzRlWW5VxmqUYZPizNlLEt5d",
  "token_type":"Bearer",
  "expires_in":899
}

If the submitted Refresh Token is more than 24 hours old, the request will cause it to expire and the response will include a newly issued Refresh Token to replace it.

{                  
  "access_token":"PjDfNvebN6cPucQzRlKl7tMH7zPU",
  "refresh_token":"w8eT84qrPWgY85b2PmDrNwrbNMYqCiH7zPUI99xbNR",
  "token_type":"Bearer",
  "expires_in":899
}

Accessing Protected Resources

OAuth 2.0 defines multiple ways to send Access Tokens in requests for Protected Resources, but FactSet only supports the Authorization HTTP request header method.

Script Execution

The access-protected-resource.sh script calls a FactSet API endpoint with an Access Token in the authorization header. When executed at the command-line without any arguments, it outputs expected usage:

$ ./access-protected-resource.sh

Usage: ./access-protected-resource.sh -option1 arg1 -option2 arg2 ...

Required options:

-a Access Token
-u Protected Resource URL

access-protected-resource.sh works in concert with the Client Credentials flow and the Authorization Code flow scripts. In the following example, request-token-with-client-creds.sh obtains an Access Token via Client Credentials flow. The specified scope narrows access to reading lookups data from the PA Engine API, an API that provides analytics for multi-asset class performance, attribution, and risk.

./request-token-with-client-creds.sh -c af00cec026bf470db25031d25abc1a8f -d https://auth.factset.com/.well-known/openid-configuration -p ./pem.txt -k ed5e11169ee24b14ba8923246afb2cd6 -s "https://api.factset.com/analytics/lookups.pa.readonly"

[access_token]
WmYhMqeQqeWrraziCcDEMGFPMHnm

[token_type]
Bearer

[expires_in]
899

Below, the newly issued Access Token is provided as an argument of access-protected-resource.sh along with the URL of the endpoint that lists all the frequencies that can be applied to a PA calculation. Note that, while FactSet scope names resemble URLs, there is not necessarily a 1-to-1 correspondence between a scope name and a FactSet API endpoint.

./access-protected-resource.sh -a WmYhMqeQqeWrraziCcDEMGFPMHnm -u https://api.factset.com/analytics/lookups/v2/engines/pa/frequencies

{
  "Single": {
    "name": "Single"
  },
  "FiscalYearly": {
    "name": "Fiscal Yearly"
  },
  "Annually": {
    "name": "Annually"
  },
  "SemiAnnually": {
    "name": "Semi Annually"
  },
  "Quarterly": {
    "name": "Quarterly"
  },
  "Monthly": {
    "name": "Monthly"
  },
  "Weekly": {
    "name": "Weekly"
  },
  "Daily": {
    "name": "Daily"
  }
}

The resultant JSON document indicates successful authorization.

Script Internals

The script uses cURL to send the Access Token in the Authorization header of a GET request to the PA Engine API.

curl -sk -H "Authorization: Bearer WmYhMqeQqeWrraziCcDEMGFPMHnm" "https://api.factset.com/analytics/lookups/v2/engines/pa/frequencies"

The HTTP GET will look something like the following.

GET /analytics/lookups/v2/engines/pa/frequencies HTTP/2
Host: api.factset.com
User-Agent: curl/7.58.0
Accept: */*
Authorization: Bearer WmYhMqeQqeWrraziCcDEMGFPMHnm

The script pipes the response to jq to pretty-print it.

If the Access Token expired or it is invalid because the Resource Owner revoked permissions, the Authorization Server will respond with a 401 Unauthorized:

HTTP/2 401
www-authenticate: FactSet-JWT
content-length: 794
content-type: text/html

If the Access Token is corrupted or the request is malformed, the Authorization Server will redirect to the FactSet login page:

HTTP/2 302
location: https://login.factset.com/login/login.html?redirect=https%3A%2F%2Fapi.factset.com%2Fanalytics%2Flookups%2Fv2%2Fengines%2Fpa%2Ffrequencies
cache-control: no-cache, no-store
content-length: 0

Token Exchange Flow

In Token Exchange Flow, the Client application obtains a User Token—a JWS containing an identifier that corresponds to a machine account the Client wants to impersonate—from the Client's Authentication Server. The Client application sends the User Token to FactSet's Authorization Server, which responds with an Access Token with the rights of the machine account.

Before a Client application employs Token Exchange, a Confidental Client must be created via the Developer Portal, and configured for Token Exchange. Please work with your FactSet Engineering contact on this process. Be prepared to provide the Client ID, the Authorization Server's JWKS URI, the Authorization Server's issuer, the identifier in the User Token, and the machine account the identifier corresponds to.

Note: FactSet's Authorization Server requires a JWKS URI, a public URI that contains the signing keys for the User Token.

The steps of Token Exchange follow.

The Client application obtains a User Token from its Authorization Server. In the User Token's payload, the Issuer (iss) and the Subject (sub) must match the registered values. Refer to the JSON Web Signature (JWS) section for the remaining payload the fields, the JOSE header, and the JWS signature.

The Client application sends the User Token to FactSet's Authorization Server:

POST /as/token.oauth2 HTTP/1.1
Host: https://auth.factset.com 
Content-Type: application/x-www-form-urlencoded 

grant_type=urn%3Aietf%3Aparams%3Aoauth%3Agrant-type%3Atoken-exchange
&subject_token=eyJiEv61PkKl7CMH7oHXqTIIELc5bLP2xcphYYzPMI9jXbNJM...8YP9Km0c5bLP
&subject_token_type=urn%3Aietf%3Aparams%3Aoauth%3Atoken-type%3Ajwt

Below is an explanation of each request body query parameter.

grant_type is urn:ietf:params:oauth:grant-type:token-exchange to indicate Token Exchange.
subject_token is the User Token, the generated JWS used to authenticate the Client.
subject_token_type is urn:ietf:params:oauth:token-type:jwt to specify the subject token type as JWT.

FactSet's Authorization Server returns an Access Token:

HTTP/1.1 200 OK
Content-Type: application/json
Cache-Control: no-cache, no-store
{
  "access_token":"f8GQ789Km0LI35U63naTHiEvBoHX",
  "issued_token_type":"urn:ietf:params:oauth:token-type:access_token",
  "token_type":"Bearer",
  "expires_in":899
}

Cache Strategies

This section discusses strategies to avoid repeating OAuth 2.0 operations unnecessarily.

Discovery Document

The Discovery Document will rarely if ever change. The document can be safely cached for 30 days. It does not need to be retrieved at the start of each OAuth 2.0 flow.

Access Tokens

When the Authorization Server issues an Access Token, the response includes the token’s lifetime:

./request-token-with-client-creds.sh -c af00cec026bf470db25031d25abc1a8f -d https://auth.factset.com/.well-known/openid-configuration -p ./pem.txt -k ed5e11169ee24b14ba8923246afb2cd6 -s "https://api.factset.com/analytics/lookups.pa.readonly"

[access_token]
WmYhMqeQqeWrraziCcDEMGFPMHnm

[token_type]
Bearer

[expires_in]
899

In this case, the Access Token expires in 899 seconds, or approximately 15 minutes. It can be reused for that period, providing access to multiple FactSet API endpoints without repeating an OAuth 2.0 flow.

The Resource Owner can rescind permissions granted to a Client at any time. Attempting to access a FactSet API endpoint with an expired Access Token will result in a 401 Unauthorized.

Refresh Tokens

The expiration period declared by an Authorization Code flow refers to the Access Token. The response does not include a lifetime for the Refresh Token, as shown below.

$ ./request-tokens-with-auth-code.sh -c d2228aeb8e434fcaad9d77309b9bebf5 -r https://example.com/callback -d https://auth.factset.com/.well-known/openid-configuration -o gCjbfsbc9x7glnFUTyVb4wnZZXxrESnaFOEqzU8u -v Msvp2UQGOwN2hTE3iFR9Ul479jssKk1lFsSAz0P5ZdS -p ./pem.txt -k ed5e11169ee24b14ba8923246afb2cd6

[access_token]
dl94d6OvcQzLEqUYZR5qxmPKuMlt

[refresh_token]
r3cd5czUdE8szHxXLICTmXBfqtHKQUsyMw6Rtp3ai

[token_type]
Bearer

[expires_in]
899

Here are some rules governing Refresh Token expiration:

The Resource Owner can rescind permissions granted to a Client at any time, expiring existing Refresh Tokens.
Refresh Tokens automatically expire after 30 days of disuse.
Refresh Tokens may be exchanged for new Access Tokens and new Refresh Tokens for up to a year. After that, the Client must initiate an Authorization Code flow, prompting the Resource Owner to log into FactSet and to grant permissions again.
The Authorization Server indexes Refresh Tokens using the triplet (Client ID, Resource Owner ID, granted permissions) as the key. If an Authorization Code flow is repeated for the same triplet, the existing Refresh Token will be invalidated.
To enhance security, Refresh Tokens are cycled. If a Refresh Token is more than 24 hours old, using it to acquire a new Access Token will also provide a new Refresh Token. The process of issuing a new Refresh Token expires the old one.

The only way to determine if a Refresh Token is expired or otherwise invalid is to attempt to use it to obtain a new Access Token. The following example shows a failed attempt.

$ ./request-tokens-with-refresh-token.sh -c d2228aeb8e434fcaad9d77309b9bebf5 -r https://example.com/callback -d https://auth.factset.com/.well-known/openid-configuration -t r3cd5czUdE8szHxXLICTmXBfqtHKQUsyMw6Rtp3ai -p ./pem.txt -k ed5e11169ee24b14ba8923246afb2cd6

[error_description]
unknown, invalid, or expired refresh token

[error]
invalid_grant

Client Credentials Flow

A Client application that employs Client Credentials flow is limited to accessing the Protected Resources of a single Resource Owner. The flow does not involve Refresh Tokens. But the flow could be used repeatedly to create Access Tokens of varying scope. Consequentially, a Client Clients flow Client needs to maintain a cache where the key is a scopes set and the value is an Access Token paired with an expiration time:

{ scopes set } -> { Access Token, expiration }

When the Client needs to access a FactSet API endpoint, it queries the cache for a non-expired Access Token containing the scopes required by the endpoint.

If no Access Token is found, the Client executes a Client Credentials flow, presenting the required scopes in the request.

If the flow succeeds, the newly issued Access Token along with its expiration time is added to the cache.
If the flow fails, it retries. But, after a certain number of attempts, the Client treats the endpoint as inaccessible.

The newly-issued or cache-retrieved Access Token is sent in the FactSet API endpoint request.

If it responds with a 200 OK, then the Client application successfully accessed the FactSet API endpoint.
If it responds with a 401 Unauthenticated, then the (presumably cache-retrieved) Access Token is invalid (even if non-expired).
- The Access Token is removed from the cache.
- The entire procedure above is repeated. But, after a certain number of attempts, the Client treats the endpoint as inaccessible.

Authorization Code Flow

A Client application that employs Authorization Code flow may access the Protected Resources of multiple Resource Owners. The flow could be used repeatedly to create Access Tokens of varying scopes. Consequentially, an Authorization Code flow Client needs to maintain a cache where the key is a Resource Owner ID paired with a scopes set and the value is a triplet containing an Access Token, an expiration time, and a Refresh Token:

{ Resource Owner ID, scopes set } -> { Access Token, expiration, Refresh Token }

When a Resource Owner logs in to the Client application, the application either creates a new session or it restores an existing session to maintain user state. The login process captures a Resource Owner ID into the session.

When the Client needs to access a FactSet API endpoint on behalf of a Resource Owner, it queries the cache using the scopes set required by the endpoint.

If the cache doesn’t contain a non-expired Access Token, but it does have a Refresh Token, then the Client presents the Refresh Token and the required scopes in a request for a new Access Token, directly with the Authorization Sever.

If the request succeeds, the cache is updated with the newly issued Access Token along with its expiration time and, potentially, a newly issued Refresh Token.
If the request fails, then the Refresh Token is invalid. The Client initiates an Authorization Code flow.
- If the flow succeeds, the cache is updated with the newly issued Access Token, its expiration time, and the newly issued Refresh Token. Critically, the scopes set used in the cache key comes from the Authorization Code flow response, not the scopes set sent in the flow request; the Resource Owner may narrow the requested scopes on the consent screen.
- If the flow fails, the Client treats the endpoint as inaccessible.

The newly-issued or cache-retrieved Access Token is sent in the FactSet API endpoint request.

If it responds with a 200 OK, then the Client application successfully accessed the FactSet API endpoint.
If it responds with a 401 Unauthenticated, then the (presumably cache-retrieved) Access Token is invalid (even if non-expired).
- If a Refresh Token is available, the Client tries the procedure described above for Refresh Tokens, which may result in a second attempt to access the FactSet API endpoint.
- Otherwise, the Client initiates an Authorization Code flow, following the resultant logic above, which may result in a second attempt to access the FactSet API endpoint.

Name		Name	Last commit message	Last commit date
Latest commit History 5 Commits
LICENSE		LICENSE
README.md		README.md
access-protected-resource.sh		access-protected-resource.sh
common.sh		common.sh
create-auth-code-url.sh		create-auth-code-url.sh
request-token-with-client-creds.sh		request-token-with-client-creds.sh
request-tokens-with-auth-code.sh		request-tokens-with-auth-code.sh
request-tokens-with-refresh-token.sh		request-tokens-with-refresh-token.sh

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FactSet's OAuth 2.0 Guidelines

Table of Contents

Client Types

Public Clients

Confidential Clients

Discovery Document

JSON Web Signature (JWS)

JWS Components

JOSE Header

JWS Payload

JWS Signature

JWS Compact Serialization

JWK Set (JWKS)

JWK Parameters

Distribution

Examples

Privacy-Enhanced Mail (PEM) Keys

Testing OAuth 2.0

Client Credentials Flow

Script Execution

Script Internals

Authorization Code Flow

Front-channel Phase

Back-channel Phase

Script Execution

Script Internals

Public Clients POST Request

Confidential Clients POST Request

POST Response

Refresh Tokens

Script Execution

Script Internals

Public Clients POST Request

Confidential Clients POST Request

POST Response

Accessing Protected Resources

Script Execution

Script Internals

Token Exchange Flow

Cache Strategies

Discovery Document

Access Tokens

Refresh Tokens

Client Credentials Flow

Authorization Code Flow

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