Docker Registry v2 authentication using OAuth2
This document describes support for the OAuth2 protocol within the authorization
server. RFC6749 should be used as a
reference for the protocol and HTTP endpoints described here.
Refresh token format
The format of the refresh token is completely opaque to the client and should be
determined by the authorization server. The authorization should ensure the
token is sufficiently long and is responsible for storing any information about
long-lived tokens which may be needed for revoking. Any information stored
inside the token will not be extracted and presented by clients.
Getting a token
(REQUIRED) Type of grant used to get token. When getting a refresh token
using credentials this type should be set to "password" and have the
accompanying username and password paramters. Type "authorization_code"
is reserved for future use for authenticating to an authorization server
without having to send credentials directly from the client. When
requesting an access token with a refresh token this should be set to
(REQUIRED) The name of the service which hosts the resource to get
access for. Refresh tokens will only be good for getting tokens for
(REQUIRED) String identifying the client. This client_id does not need
to be registered with the authorization server but should be set to a
meaningful value in order to allow auditing keys created by unregistered
clients. Accepted syntax is defined in
[RFC6749 Appendix A.1](https://tools.ietf.org/html/rfc6749#appendix-A.1)
(OPTIONAL) Access which is being requested. If "offline" is provided
then a refresh token will be returned. The default is "online" only
returning short lived access token. If the grant type is "refresh_token"
this will only return the same refresh token and not a new one.
(OPTIONAL) The resource in question, formatted as one of the space-delimited
entries from the
scope parameters from the
shown above. This query parameter should only be specified once but may
contain multiple scopes using the scope list format defined in the scope
grammar. If multiple
scope is provided from
WWW-Authenticate header the scopes should first be
converted to a scope list before requesting the token. The above example
would be specified as:
When requesting a refresh token the scopes may be empty since the
refresh token will not be limited by this scope, only the provided short
lived access token will have the scope limitation.
(OPTIONAL) The refresh token to use for authentication when grant type "refresh_token" is used.
(OPTIONAL) The username to use for authentication when grant type "password" is used.
(OPTIONAL) The password to use for authentication when grant type "password" is used.
(REQUIRED) An opaque
Bearer token that clients should
supply to subsequent requests in the
This token should not be attempted to be parsed or understood by the
client but treated as opaque string.
(REQUIRED) The scope granted inside the access token. This may be the
same scope as requested or a subset. This requirement is stronger than
specified in [RFC6749 Section 4.2.2](https://tools.ietf.org/html/rfc6749#section-4.2.2)
by strictly requiring the scope in the return value.
(REQUIRED) The duration in seconds since the token was issued that it
will remain valid. When omitted, this defaults to 60 seconds. For
compatibility with older clients, a token should never be returned with
less than 60 seconds to live.
(Optional) The RFC3339-serialized UTC
standard time at which a given token was issued. If
issued_at is omitted, the
expiration is from when the token exchange completed.
(Optional) Token which can be used to get additional access tokens for
the same subject with different scopes. This token should be kept secure
by the client and only sent to the authorization server which issues
bearer tokens. This field will only be set when `access_type=offline` is
provided in the request.
Example getting refresh token
POST /token HTTP/1.1
HTTP/1.1 200 OK
Example refreshing an Access Token
POST /token HTTP/1.1
HTTP/1.1 200 OK