Patrick Jones d3ed898aa8 google: support url-sourced 3rd party credentials
Implements functionality to allow for URL-sourced 3rd party credentials, expanding the functionality added in #462 .

Change-Id: Ib7615fb618486612960d60bee6b9a1ecf5de1404
GitHub-Last-Rev: 95713928e495d51d2209bb81cbf2c16185441145
GitHub-Pull-Request: golang/oauth2#466
Reviewed-on: https://go-review.googlesource.com/c/oauth2/+/283372
Run-TryBot: Cody Oss <codyoss@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cody Oss <codyoss@google.com>
Trust: Tyler Bui-Palsulich <tbp@google.com>
Trust: Cody Oss <codyoss@google.com>
2021-01-13 20:58:17 +00:00

72 lines
1.8 KiB
Go

// Copyright 2020 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package externalaccount
import (
"context"
"encoding/json"
"errors"
"fmt"
"golang.org/x/oauth2"
"io"
"io/ioutil"
"net/http"
)
type urlCredentialSource struct {
URL string
Headers map[string]string
Format format
ctx context.Context
}
func (cs urlCredentialSource) subjectToken() (string, error) {
client := oauth2.NewClient(cs.ctx, nil)
req, err := http.NewRequest("GET", cs.URL, nil)
if err != nil {
return "", fmt.Errorf("oauth2/google: HTTP request for URL-sourced credential failed: %v", err)
}
req = req.WithContext(cs.ctx)
for key, val := range cs.Headers {
req.Header.Add(key, val)
}
resp, err := client.Do(req)
if err != nil {
return "", fmt.Errorf("oauth2/google: invalid response when retrieving subject token: %v", err)
}
defer resp.Body.Close()
tokenBytes, err := ioutil.ReadAll(io.LimitReader(resp.Body, 1<<20))
if err != nil {
return "", fmt.Errorf("oauth2/google: invalid body in subject token URL query: %v", err)
}
switch cs.Format.Type {
case "json":
jsonData := make(map[string]interface{})
err = json.Unmarshal(tokenBytes, &jsonData)
if err != nil {
return "", fmt.Errorf("oauth2/google: failed to unmarshal subject token file: %v", err)
}
val, ok := jsonData[cs.Format.SubjectTokenFieldName]
if !ok {
return "", errors.New("oauth2/google: provided subject_token_field_name not found in credentials")
}
token, ok := val.(string)
if !ok {
return "", errors.New("oauth2/google: improperly formatted subject token")
}
return token, nil
case "text":
return string(tokenBytes), nil
case "":
return string(tokenBytes), nil
default:
return "", errors.New("oauth2/google: invalid credential_source file format type")
}
}