zitadel-oidc/pkg/client/tokenexchange/tokenexchange.go
2023-03-20 13:38:21 +02:00

127 lines
3.2 KiB
Go

package tokenexchange
import (
"errors"
"net/http"
"github.com/zitadel/oidc/v3/pkg/client"
httphelper "github.com/zitadel/oidc/v3/pkg/http"
"github.com/zitadel/oidc/v3/pkg/oidc"
)
type TokenExchanger interface {
TokenEndpoint() string
HttpClient() *http.Client
AuthFn() (interface{}, error)
}
type OAuthTokenExchange struct {
httpClient *http.Client
tokenEndpoint string
authFn func() (interface{}, error)
}
func NewTokenExchanger(issuer string, options ...func(source *OAuthTokenExchange)) (TokenExchanger, error) {
return newOAuthTokenExchange(issuer, nil, options...)
}
func NewTokenExchangerClientCredentials(issuer, clientID, clientSecret string, options ...func(source *OAuthTokenExchange)) (TokenExchanger, error) {
authorizer := func() (interface{}, error) {
return httphelper.AuthorizeBasic(clientID, clientSecret), nil
}
return newOAuthTokenExchange(issuer, authorizer, options...)
}
func newOAuthTokenExchange(issuer string, authorizer func() (interface{}, error), options ...func(source *OAuthTokenExchange)) (*OAuthTokenExchange, error) {
te := &OAuthTokenExchange{
httpClient: httphelper.DefaultHTTPClient,
}
for _, opt := range options {
opt(te)
}
if te.tokenEndpoint == "" {
config, err := client.Discover(issuer, te.httpClient)
if err != nil {
return nil, err
}
te.tokenEndpoint = config.TokenEndpoint
}
if te.tokenEndpoint == "" {
return nil, errors.New("tokenURL is empty: please provide with either `WithStaticTokenEndpoint` or a discovery url")
}
te.authFn = authorizer
return te, nil
}
func WithHTTPClient(client *http.Client) func(*OAuthTokenExchange) {
return func(source *OAuthTokenExchange) {
source.httpClient = client
}
}
func WithStaticTokenEndpoint(issuer, tokenEndpoint string) func(*OAuthTokenExchange) {
return func(source *OAuthTokenExchange) {
source.tokenEndpoint = tokenEndpoint
}
}
func (te *OAuthTokenExchange) TokenEndpoint() string {
return te.tokenEndpoint
}
func (te *OAuthTokenExchange) HttpClient() *http.Client {
return te.httpClient
}
func (te *OAuthTokenExchange) AuthFn() (interface{}, error) {
if te.authFn != nil {
return te.authFn()
}
return nil, nil
}
// ExchangeToken sends a token exchange request (rfc 8693) to te's token endpoint.
// SubjectToken and SubjectTokenType are required parameters.
func ExchangeToken(
te TokenExchanger,
SubjectToken string,
SubjectTokenType oidc.TokenType,
ActorToken string,
ActorTokenType oidc.TokenType,
Resource []string,
Audience []string,
Scopes []string,
RequestedTokenType oidc.TokenType,
) (*oidc.TokenExchangeResponse, error) {
if SubjectToken == "" {
return nil, errors.New("empty subject_token")
}
if SubjectTokenType == "" {
return nil, errors.New("empty subject_token_type")
}
authFn, err := te.AuthFn()
if err != nil {
return nil, err
}
request := oidc.TokenExchangeRequest{
GrantType: oidc.GrantTypeTokenExchange,
SubjectToken: SubjectToken,
SubjectTokenType: SubjectTokenType,
ActorToken: ActorToken,
ActorTokenType: ActorTokenType,
Resource: Resource,
Audience: Audience,
Scopes: Scopes,
RequestedTokenType: RequestedTokenType,
}
return client.CallTokenExchangeEndpoint(request, authFn, te)
}