Configure Snowflake OAuth for Custom Clients¶

This topic describes how to configure OAuth support for custom clients.

In this Topic:

Workflow
Step 1: Create a Snowflake OAuth Integration
Step 2: Call the OAuth Endpoints
- Authorization Endpoint
  - Scope
- Token Endpoint
  - Successful Response Example
  - Unsuccessful Response Example
Proof Key for Code Exchange
Using Key Pair Authentication
- Key Rotation
Error Codes
Pre-Authorizing User Consent for a Role

Workflow¶

The following high-level steps are required to configure OAuth for custom clients:

Register your client with Snowflake. To register your client, create an integration. An integration is a Snowflake object that provides an interface between Snowflake and third-party services, such as a client that supports OAuth.

The registration process defines a client ID and client secrets.
Configure calls to the Snowflake OAuth endpoints to request authorization codes from the Snowflake authorization server and to request and refresh access tokens.

The optional “scope” parameters in the initial authorization request limit the role permitted by the access token and can additionally be used to configure the refresh token behavior.

Note

In-session role switching to secondary roles is not supported with Snowflake OAuth.

If this behavior is necessary with your OAuth workflow, use External OAuth instead.

For more information, see Using Secondary Roles with External OAuth.

Step 1: Create a Snowflake OAuth Integration¶

Create a Snowflake OAuth integration using the CREATE SECURITY INTEGRATION (Snowflake OAuth) command.

Note

Only account administrators (users with the ACCOUNTADMIN role) or a role with the global CREATE INTEGRATION privilege can execute this SQL command.

Blocking Specific Roles from Using the Integration¶

The optional BLOCKED_ROLES_LIST parameter allows you to list Snowflake roles that a user cannot explicitly consent to using with the integration.

By default, the account administrator (i.e users with the ACCOUNTADMIN system role) and security administrator (i.e users with the SECURITYADMIN system role) roles are included in this list and cannot be removed. If you have a business need to allow users to use OAuth with these roles, and your security team is comfortable with allowing it, please contact Snowflake Support to request that these roles be allowed for your account.

Using Client Redirect with Snowflake OAuth Custom Clients¶

Snowflake supports using Client Redirect with Snowflake OAuth Custom Clients, including using Client Redirect and OAuth with supported Snowflake Clients.

For more information, see Redirecting Client Connections.

Managing Network Policies¶

Snowflake supports network policies for OAuth. For more information, see OAuth and Network Policies.

Integration Example¶

The following example creates an OAuth integration that uses key pair authentication. The integration allows refresh tokens, which expire after 1 day (86400 seconds). The integration blocks users from starting a session with SYSADMIN as the active role:

CREATE SECURITY INTEGRATION oauth_kp_int
  TYPE = OAUTH
  ENABLED = TRUE
  OAUTH_CLIENT = CUSTOM
  OAUTH_CLIENT_TYPE = 'CONFIDENTIAL'
  OAUTH_REDIRECT_URI = 'https://localhost.com'
  OAUTH_ISSUE_REFRESH_TOKENS = TRUE
  OAUTH_REFRESH_TOKEN_VALIDITY = 86400
  BLOCKED_ROLES_LIST = ('SYSADMIN')
  OAUTH_CLIENT_RSA_PUBLIC_KEY ='
  MIIBI
  ...
  ';

Step 2: Call the OAuth Endpoints¶

OAuth endpoints are the URLs that clients call to request authorization codes and to request and refresh access tokens. These endpoints refer to specific OAuth 2.0 policies that execute when the endpoint is called.

Snowflake provides the following OAuth endpoints:

Authorization: <snowflake_account_url>/oauth/authorize
Token requests: <snowflake_account_url>/oauth/token-request

Where <snowflake_account_url> is a valid Snowflake account URL. For example, you might use the endpoints https://myorg-account_xyz.snowflakecomputing.com/oauth/authorize and https://myorg-account_xyz.snowflakecomputing.com/oauth/token-request. For a list of supported formats for the Snowflake account URL, see Connecting with a URL.

To see a list of valid OAuth endpoints for a security integration, execute DESCRIBE INTEGRATION, and then view the values in the OAUTH_ALLOWED_AUTHORIZATION_ENDPOINTS and OAUTH_ALLOWED_TOKEN_ENDPOINTS properties.

Authorization Endpoint¶

The authorization endpoint is used to obtain an authorization grant after a user successfully authorizes a client with Snowflake. The authorization endpoint is as follows:

<snowflake_account_url>/oauth/authorize

Where:

<snowflake_account_url>
Specifies a valid Snowflake account URL. For example, https://myorg-account_xyz.snowflakecomputing.com/oauth/authorize.

method: GET

Important

The authorization endpoint must be opened in a browser that the user can interact with. Do not use cURL with this endpoint.

query parameters

Note

The following parameters should be URL encoded.

Parameter	Data Type	Required	Description
`client_id`	String	Yes	Client ID (provided by Snowflake when the client is registered)
`response_type`	String	Yes	Response type created. Currently supports `code` value, because Snowflake only issues authorization codes.
`redirect_uri`	String	Yes	URI where the user is redirected to after successfully authorizing. Must match the value registered with Snowflake during the client registration.
`state`	String	No	String of no more than 2048 ASCII characters that is returned with the response from the Snowflake authorization server. Typically used to prevent cross-site request forgery attacks.
`scope`	String	No	Space-delimited string that is used to limit the scope of the access request. For more information, see Scope in this topic.
`code_challenge`	String	No	Challenge for Proof Key for Code Exchange (PKCE). String generated via a secret and a code challenge method. For more information, see Proof Key for Code Exchange (in this topic).
`code_challenge_method`	String	No	String indicating the method used to derive the code challenge for PKCE. For more information, see Proof Key for Code Exchange (in this topic).

When a user authorizes the client, a redirect is made to the redirect_uri that contains the following in a GET request:

Parameter

Description

code

Short-lived authorization code, which can be exchanged at the token endpoint for an access token.

state

state value provided in the original request, unmodified.

scope

Scope of the access request; currently the same as the scope value in the initial authorization request, but might differ in the future. For more information, see Scope (in this topic).

Scope¶

The scope parameters in the initial authorization request optionally limit the operations and role permitted by the access token.

Scope is validated immediately when making an authorization request with respect to semantics, but not necessarily validity. That is, any invalid scopes (e.g. “bogus_scope”) are rejected before the user authenticates, but a scope the user does not have access to (a particular role, etc.) does not result in an error until after the user authenticates. Valid scope parameters are as follows:

query parameters

Parameter	Required	Description
`refresh_token`	No	If included in the authorization URL, Snowflake presents the user with the option to consent to offline access. In this context, offline access refers to allowing the client to refresh access tokens when the user is not present. With user consent, the authorization server returns a refresh token in addition to an access token when redeeming the authorization code.
`session:role:role_name`	No	Used to limit the access token to a single role that the user can consent to for the session. Only one session role scope can be specified. If this scope is omitted, then the default role for the user is used instead. When a user authorizes consent, Snowflake always displays the role for the session regardless if this scope is included in the authorization URL. . Note that `role_name` is case-sensitive and must be input in all uppercase unless the role name was enclosed in quotes when it was created using CREATE ROLE. To verify the case, execute SHOW ROLES in Snowflake and see the role name in the output.

Append scope parameters to the authorization URL.

The following example limits authorization to the custom R1 role:

scope=session:role:R1

The following example indicates that access/refresh tokens should use the default role for the user and requests a refresh token so that offline access can occur:

scope=refresh_token

The following example limits authorization to the custom R1 role and requests a refresh token so that offline access can occur:

scope=refresh_token session:role:R1

Token Endpoint¶

This endpoint returns access tokens or refresh tokens depending on the request parameters. The token endpoint is as follows:

<snowflake_account_url>/oauth/token-request

Where:

<snowflake_account_url>
Specifies a valid Snowflake account URL. For example, https://myorg-account_xyz.snowflakecomputing.com/oauth/token-request.

method: POST

body parameters

Parameter	Data Type	Required	Description
`grant_type`	String	Yes	Type of grant requested: . `authorization_code` indicates that an authorization code should be exchanged for an access token. . `refresh_token` indicates a request to refresh an access token.
`code`	String	Yes	Authorization code returned from the token endpoint. Used and required when `grant_type` is set to `authorization_code`.
`refresh_token`	String	Yes	Refresh token returned from an earlier request to the token endpoint when redeeming the authorization code. Used and required when `grant_type` is set to `refresh_token`.
`redirect_uri`	String	Yes	Redirect URI as specified in the security integration (see Step 1: Create a Snowflake OAuth Integration) and used in the authorization URL when requesting an authorization code. Used and required when `grant_type` is set to `authorization_code`.
`code_verifier`	String	No	Required only if the authorization request was sent to the Authorization Endpoint with a `code_challenge` parameter value. Code verifier for PKCE. For more information, see Proof Key for Code Exchange (in this topic).

The client ID and client secret must be included in the authorization header. Currently, Snowflake only supports the Basic Authentication Scheme, which means that the value expected is in the following form:

Basic Base64(client_id:client_secret)

Where:

Parameter	Data Type	Required	Description
`client_id`	String	Yes	Client ID of the integration.
`client_secret`	String	Yes	Client secret for the integration.

Both the client ID and client secret can be retrieved using the SYSTEM$SHOW_OAUTH_CLIENT_SECRETS function.

Note the : character between client_id and client_secret.

response body

A JSON object is returned with the following attributes:

Parameter	Data Type	Description
`access_token`	String	Access token used to establish a Snowflake session
`refresh_token`	String	Refresh token. Not issued if the client is configured to not issue refresh tokens or if the user did not consent to the `refresh_token` scope.
`expires_in`	Integer	Number of seconds remaining until the token expires
`token_type`	String	Access token type. Currently, always `Bearer`.
`username`	String	Username that the access token belongs to. Currently only returned when exchanging an authorization code for an access token.

Ensure that the content-type header in the POST message is set as follows:

Content-type: application/x-www-form-urlencoded

Successful Response Example¶

The following example shows a successful response when exchanging an authorization code for an access and refresh token:

{
  "access_token":  "ACCESS_TOKEN",
  "expires_in": 600,
  "refresh_token": "REFRESH_TOKEN",
  "token_type": "Bearer",
  "username": "user1",
}

Unsuccessful Response Example¶

The following example shows an unsuccessful response:

{
  "data" : null,
  "message" : "This is an invalid client.",
  "code" : null,
  "success" : false,
  "error" : "invalid_client"
}

The message string value is a description of the error and error is the error type. For more information on the types of errors returned, see OAuth Error Codes.

Proof Key for Code Exchange¶

Snowflake supports Proof Key for Code Exchange (PKCE) for obtaining access tokens using the authorization_code grant type as described in RFC 7636. PKCE can be used to lessen the possibility of an authorization code interception attack, and is suitable for clients that might not be able to fully keep the client secret secure.

By default, PKCE is optional and is enforced only if the code_challenge and code_challenge_method parameters are both included in the authorization endpoint URL. However, Snowflake highly recommends that your client require PKCE for all authorizations to make the OAuth flow more secure.

The following describes how PKCE for Snowflake works:

The client creates a secret called the code verifier and performs a transformation on it to generate the code challenge. The client holds onto the secret.

Important

Generate the code verifier from the allowed ASCII characters according to Section 4.1 of RFC 7636.
The client directing the user to the Authorization URL appends the following two query parameters:

code_challenge
Specifies the code challenge generated in Step 1.

code_challenge_method
Specifies the transformations used on the code verifier in Step 1 to generate the code challenge. Currently, Snowflake only supports SHA256, so this value must be set to S256. The transformation algorithm for SHA256 is BASE64URL-ENCODE(SHA256(ASCII(code_verifier))).
After the user consents to the requested scopes or Snowflake determines that consent is present for that user, the authorization code is issued.
The client receives the authorization code from the Snowflake authorization server, which it then submits along with the code_verifier in the request to the token endpoint.
Snowflake transforms the code_verifier value and verifies that the transformed value matches the code_challenge value used when generating authorizations. If these values match, then the authorization server issues the access and refresh tokens.

Using Key Pair Authentication¶

Snowflake supports using key pair authentication rather than the typical username/password authentication when calling the OAuth token endpoint. This authentication method requires a 2048-bit (minimum) RSA key pair. Generate the PEM (Privacy Enhanced Mail) public-private key pair using OpenSSL. The public key is assigned to the Snowflake user who uses the Snowflake client.

To configure the public/private key pair:

From the command line in a terminal window, generate an encrypted private key:
$ openssl genrsa 2048 | openssl pkcs8 -topk8 -v2 des3 -inform PEM -out rsa_key.p8
OpenSSL prompts for a passphrase used to encrypt the private key file. Snowflake recommends using a strong passphrase to protect the private key. Record this passphrase. You must input it when connecting to Snowflake. Note that the passphrase is only used for protecting the private key and is never sent to Snowflake.

Sample PEM private key
-----BEGIN ENCRYPTED PRIVATE KEY----- MIIE6TAbBgkqhkiG9w0BBQMwDgQILYPyCppzOwECAggABIIEyLiGSpeeGSe3xHP1 wHLjfCYycUPennlX2bd8yX8xOxGSGfvB+99+PmSlex0FmY9ov1J8H1H9Y3lMWXbL ... -----END ENCRYPTED PRIVATE KEY-----

From the command line, generate the public key by referencing the private key:

$ openssl rsa -in rsa_key.p8 -pubout -out rsa_key.pub

Sample PEM public key

-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAy+Fw2qv4Roud3l6tjPH4
zxybHjmZ5rhtCz9jppCV8UTWvEXxa88IGRIHbJ/PwKW/mR8LXdfI7l/9vCMXX4mk
...
-----END PUBLIC KEY-----

Copy the public and private key files to a local directory for storage. Record the path to the files.

Note that the private key is stored using the PKCS#8 (Public Key Cryptography Standards) format and is encrypted using the passphrase you specified in the previous step; however, the file should still be protected from unauthorized access using the file permission mechanism provided by your operating system. It is your responsibility to secure the file when it is not being used.

Assign the public key to the integration object using ALTER SECURITY INTEGRATION (Snowflake OAuth). For example:

ALTER SECURITY INTEGRATION myint SET OAUTH_CLIENT_RSA_PUBLIC_KEY='MIIBIjANBgkqh...';

Note

Only account administrators can execute the ALTER SECURITY INTEGRATION command.
Exclude the public key header and footer in the command.

Verify the public key fingerprint using DESCRIBE INTEGRATION:

DESC SECURITY INTEGRATION myint;

+----------------------------------+---------------+----------------------------------------------------------------------+------------------+
| property                         | property_type | property_value                                                       | property_default |
|----------------------------------+---------------+----------------------------------------------------------------------+------------------|
...
| OAUTH_CLIENT_RSA_PUBLIC_KEY_FP   | String        | SHA256:MRItnbO/123abc/abcdefghijklmn12345678901234=                  |                  |
| OAUTH_CLIENT_RSA_PUBLIC_KEY_2_FP | String        |                                                                      |                  |
...
+----------------------------------+---------------+----------------------------------------------------------------------+------------------+

Note

The OAUTH_CLIENT_RSA_PUBLIC_KEY_2_FP property is described in Key Rotation (in this topic).

Modify and execute the sample code below. The code uses the private key to encode a JWT and then passes that token to the Snowflake authorization server:

Update the security parameters:
- <private_key>: Open the rsa_key.p8 file in a text editor, and copy the lines between the BEGIN header and the END footer.
Update the session parameters:
- <account_identifier>: Specifies the full name of your account (provided by Snowflake).

Update the JSON Web Token (JWT) fields:

post body: A JSON object with the following standard fields (“claims”):

Attribute	Data Type	Required	Description
`iss`	String	Yes	Specifies the principal that issued the JWT in the format `client_id.public_key_fp` where `client_id` is the client ID of the OAuth client integration and `public_key_fp` is the fingerprint of the public key that is used during verification.
`sub`	String	Yes	Subject of the JWT in the format `account_identifier.client_id` where `account_identifier` is the full name of your Snowflake account and `client_id` is the client ID of the OAuth client integration. Depending on the cloud platform (AWS or Azure) and region where your account is hosted, the full account name might require additional segments. For more information, see the `account` variable description under Token Endpoint.
`iat`	Timestamp	No	Time when the token was issued.
`exp`	Timestamp	Yes	Time when the token should expire. This period should be relatively short (e.g. a few minutes).

Sample code

Note that the private_key value includes the -----BEGIN header and the -----END footer.

import datetime
import json
import urllib

import jwt
import requests

private_key = """
<private_key>
"""

public_key_fp = "SHA256:MR..."


def _make_request(payload, encoded_jwt_token):
    token_url = "https://<account_identifier>.snowflakecomputing.com/oauth/token-request"
    headers = {
            u'Authorization': "Bearer %s" % (encoded_jwt_token),
            u'content-type': u'application/x-www-form-urlencoded'
    }
    r = requests.post(
            token_url,
            headers=headers,
            data=urllib.urlencode(payload))
    return r.json()


def make_request_for_access_token(oauth_az_code, encoded_jwt_token):
    """ Given an Authorization Code, make a request for an Access Token
    and a Refresh Token."""
    payload = {
        'grant_type': 'authorization_code',
        'code': oauth_az_code
    }
    return _make_request(payload, encoded_jwt_token)


def make_request_for_refresh_token(refresh_token, encoded_jwt_token):
    """ Given a Refresh Token, make a request for another Access Token."""
    payload = {
        'grant_type': 'refresh_token',
        'refresh_token': refresh_token
    }
    return _make_request(payload, encoded_jwt_token)


def main():
    account_identifier = "<account_identifier>"
    client_id = "1234"  # found by running DESC SECURITY INTEGRATION
    issuer = "{}.{}".format(client_id, public_key_fp)
    subject = "{}.{}".format(account_identifier, client_id)
    payload = {
        'iss': issuer,
        'sub': subject,
        'iat': datetime.datetime.utcnow(),
        'exp': datetime.datetime.utcnow() + datetime.timedelta(seconds=30)
    }
    encoded_jwt_token = jwt.encode(
            payload,
            private_key,
            algorithm='RS256')

    data = make_request_for_access_token(oauth_az_code, encoded_jwt_token)
    refresh_token = data['refresh_token']
    data = make_request_for_refresh_token(refresh_token, encoded_jwt_token)
    access_token = data['access_token']


if __name__ == '__main__':
    main()

After the token is created, submit it in requests to the token endpoint. Requests require the Bearer authorization format as the authorization header instead of the basic authorization format normally used for the client ID and client secret, as follows:

"Authorization: Bearer JWT_TOKEN"

Key Rotation¶

Snowflake supports multiple active keys to allow for uninterrupted rotation. Rotate and replace your public and private keys based on the expiration schedule you follow internally.

Currently, you can use the OAUTH_CLIENT_RSA_PUBLIC_KEY and OAUTH_CLIENT_RSA_PUBLIC_KEY_2 parameters for ALTER SECURITY INTEGRATION (Snowflake OAuth) to associate up to 2 public keys with a single user.

To rotate your keys:

Complete the steps in Using Key Pair Authentication (in this topic):
- Generate a new private and public key set.
- Assign the public key to the integration. Set the public key value to either OAUTH_CLIENT_RSA_PUBLIC_KEY or OAUTH_CLIENT_RSA_PUBLIC_KEY_2 (whichever key value is not currently in use). For example:
  alter integration myint set oauth_client_rsa_public_key_2='JERUEHtcve...';
Update the code to connect to Snowflake. Specify the new private key.

Snowflake verifies the correct active public key for authentication based on the submitted private key.

Remove the old public key from the integration. For example:

alter integration myint unset oauth_client_rsa_public_key;

Error Codes¶

See the OAuth Error Codes for a list of error codes associated with OAuth, as well as errors that are returned in the JSON blob, during the authorization flow, token request or exchange, or when creating a Snowflake session after completing the OAuth flow.

Configure Snowflake OAuth for Custom Clients¶

Workflow¶

Step 1: Create a Snowflake OAuth Integration¶

Blocking Specific Roles from Using the Integration¶

Using Client Redirect with Snowflake OAuth Custom Clients¶

Managing Network Policies¶

Integration Example¶

Step 2: Call the OAuth Endpoints¶

Authorization Endpoint¶

Scope¶

Token Endpoint¶

Successful Response Example¶

Unsuccessful Response Example¶

Proof Key for Code Exchange¶

Using Key Pair Authentication¶

Key Rotation¶

Error Codes¶

Pre-Authorizing User Consent for a Role¶