blob: 16dca6541d98eec44e8c58c57f78d799e1c03985 [file] [log] [blame]
// 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"
"io"
"io/ioutil"
"net/http"
"golang.org/x/oauth2"
)
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()
respBody, 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)
}
if c := resp.StatusCode; c < 200 || c > 299 {
return "", fmt.Errorf("oauth2/google: status code %d: %s", c, respBody)
}
switch cs.Format.Type {
case "json":
jsonData := make(map[string]interface{})
err = json.Unmarshal(respBody, &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(respBody), nil
case "":
return string(respBody), nil
default:
return "", errors.New("oauth2/google: invalid credential_source file format type")
}
}