103 lines
3.1 KiB
Go
103 lines
3.1 KiB
Go
// Copyright 2017 Google LLC
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package internal
|
|
|
|
import (
|
|
"context"
|
|
"encoding/json"
|
|
"fmt"
|
|
"io/ioutil"
|
|
|
|
"golang.org/x/oauth2"
|
|
|
|
"golang.org/x/oauth2/google"
|
|
)
|
|
|
|
// Creds returns credential information obtained from DialSettings, or if none, then
|
|
// it returns default credential information.
|
|
func Creds(ctx context.Context, ds *DialSettings) (*google.Credentials, error) {
|
|
if ds.Credentials != nil {
|
|
return ds.Credentials, nil
|
|
}
|
|
if ds.CredentialsJSON != nil {
|
|
return credentialsFromJSON(ctx, ds.CredentialsJSON, ds.Endpoint, ds.Scopes, ds.Audiences)
|
|
}
|
|
if ds.CredentialsFile != "" {
|
|
data, err := ioutil.ReadFile(ds.CredentialsFile)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("cannot read credentials file: %v", err)
|
|
}
|
|
return credentialsFromJSON(ctx, data, ds.Endpoint, ds.Scopes, ds.Audiences)
|
|
}
|
|
if ds.TokenSource != nil {
|
|
return &google.Credentials{TokenSource: ds.TokenSource}, nil
|
|
}
|
|
cred, err := google.FindDefaultCredentials(ctx, ds.Scopes...)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
if len(cred.JSON) > 0 {
|
|
return credentialsFromJSON(ctx, cred.JSON, ds.Endpoint, ds.Scopes, ds.Audiences)
|
|
}
|
|
// For GAE and GCE, the JSON is empty so return the default credentials directly.
|
|
return cred, nil
|
|
}
|
|
|
|
// JSON key file type.
|
|
const (
|
|
serviceAccountKey = "service_account"
|
|
)
|
|
|
|
// credentialsFromJSON returns a google.Credentials based on the input.
|
|
//
|
|
// - If the JSON is a service account and no scopes provided, returns self-signed JWT auth flow
|
|
// - Otherwise, returns OAuth 2.0 flow.
|
|
func credentialsFromJSON(ctx context.Context, data []byte, endpoint string, scopes []string, audiences []string) (*google.Credentials, error) {
|
|
cred, err := google.CredentialsFromJSON(ctx, data, scopes...)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
if len(data) > 0 && len(scopes) == 0 {
|
|
var f struct {
|
|
Type string `json:"type"`
|
|
// The rest JSON fields are omitted because they are not used.
|
|
}
|
|
if err := json.Unmarshal(cred.JSON, &f); err != nil {
|
|
return nil, err
|
|
}
|
|
if f.Type == serviceAccountKey {
|
|
ts, err := selfSignedJWTTokenSource(data, endpoint, audiences)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
cred.TokenSource = ts
|
|
}
|
|
}
|
|
return cred, err
|
|
}
|
|
|
|
func selfSignedJWTTokenSource(data []byte, endpoint string, audiences []string) (oauth2.TokenSource, error) {
|
|
// Use the API endpoint as the default audience
|
|
audience := endpoint
|
|
if len(audiences) > 0 {
|
|
// TODO(shinfan): Update golang oauth to support multiple audiences.
|
|
if len(audiences) > 1 {
|
|
return nil, fmt.Errorf("multiple audiences support is not implemented")
|
|
}
|
|
audience = audiences[0]
|
|
}
|
|
return google.JWTAccessTokenSourceFromJSON(data, audience)
|
|
}
|