memos/plugin/idp/oauth2/oauth2.go
2023-09-17 22:55:13 +08:00

118 lines
3.4 KiB
Go

// Package oauth2 is the plugin for OAuth2 Identity Provider.
package oauth2
import (
"context"
"encoding/json"
"fmt"
"io"
"net/http"
"github.com/pkg/errors"
"golang.org/x/oauth2"
"github.com/usememos/memos/plugin/idp"
"github.com/usememos/memos/store"
)
// IdentityProvider represents an OAuth2 Identity Provider.
type IdentityProvider struct {
config *store.IdentityProviderOAuth2Config
}
// NewIdentityProvider initializes a new OAuth2 Identity Provider with the given configuration.
func NewIdentityProvider(config *store.IdentityProviderOAuth2Config) (*IdentityProvider, error) {
for v, field := range map[string]string{
config.ClientID: "clientId",
config.ClientSecret: "clientSecret",
config.TokenURL: "tokenUrl",
config.UserInfoURL: "userInfoUrl",
config.FieldMapping.Identifier: "fieldMapping.identifier",
} {
if v == "" {
return nil, errors.Errorf(`the field "%s" is empty but required`, field)
}
}
return &IdentityProvider{
config: config,
}, nil
}
// ExchangeToken returns the exchanged OAuth2 token using the given authorization code.
func (p *IdentityProvider) ExchangeToken(ctx context.Context, redirectURL, code string) (string, error) {
conf := &oauth2.Config{
ClientID: p.config.ClientID,
ClientSecret: p.config.ClientSecret,
RedirectURL: redirectURL,
Scopes: p.config.Scopes,
Endpoint: oauth2.Endpoint{
AuthURL: p.config.AuthURL,
TokenURL: p.config.TokenURL,
AuthStyle: oauth2.AuthStyleInParams,
},
}
token, err := conf.Exchange(ctx, code)
if err != nil {
return "", errors.Wrap(err, "failed to exchange access token")
}
accessToken, ok := token.Extra("access_token").(string)
if !ok {
return "", errors.New(`missing "access_token" from authorization response`)
}
return accessToken, nil
}
// UserInfo returns the parsed user information using the given OAuth2 token.
func (p *IdentityProvider) UserInfo(token string) (*idp.IdentityProviderUserInfo, error) {
client := &http.Client{}
req, err := http.NewRequest(http.MethodGet, p.config.UserInfoURL, nil)
if err != nil {
return nil, errors.Wrap(err, "failed to new http request")
}
req.Header.Set("Content-Type", "application/json")
req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token))
resp, err := client.Do(req)
if err != nil {
return nil, errors.Wrap(err, "failed to get user information")
}
body, err := io.ReadAll(resp.Body)
if err != nil {
return nil, errors.Wrap(err, "failed to read response body")
}
defer resp.Body.Close()
var claims map[string]any
err = json.Unmarshal(body, &claims)
if err != nil {
return nil, errors.Wrap(err, "failed to unmarshal response body")
}
userInfo := &idp.IdentityProviderUserInfo{}
if v, ok := claims[p.config.FieldMapping.Identifier].(string); ok {
userInfo.Identifier = v
}
if userInfo.Identifier == "" {
return nil, errors.Errorf("the field %q is not found in claims or has empty value", p.config.FieldMapping.Identifier)
}
// Best effort to map optional fields
if p.config.FieldMapping.DisplayName != "" {
if v, ok := claims[p.config.FieldMapping.DisplayName].(string); ok {
userInfo.DisplayName = v
}
}
if userInfo.DisplayName == "" {
userInfo.DisplayName = userInfo.Identifier
}
if p.config.FieldMapping.Email != "" {
if v, ok := claims[p.config.FieldMapping.Email].(string); ok {
userInfo.Email = v
}
}
return userInfo, nil
}