Add new B2C provider

idp/azuread_b2c.go

@@ -0,0 +1,126 @@
+// Copyright 2023 The Casdoor Authors. All Rights Reserved.
+//
+// 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 idp
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"time"
+
+	"golang.org/x/oauth2"
+)
+
+type AzureADB2CProvider struct {
+	Client   *http.Client
+	Config   *oauth2.Config
+	Tenant   string
+	UserFlow string
+}
+
+func NewAzureAdB2cProvider(clientId, clientSecret, redirectUrl, tenant string, userFlow string) *AzureADB2CProvider {
+	return &AzureADB2CProvider{
+		Config: &oauth2.Config{
+			ClientID:     clientId,
+			ClientSecret: clientSecret,
+			RedirectURL:  redirectUrl,
+			Endpoint: oauth2.Endpoint{
+				AuthURL:  fmt.Sprintf("https://%s.b2clogin.com/%s.onmicrosoft.com/%s/oauth2/v2.0/authorize", tenant, tenant, userFlow),
+				TokenURL: fmt.Sprintf("https://%s.b2clogin.com/%s.onmicrosoft.com/%s/oauth2/v2.0/token", tenant, tenant, userFlow),
+			},
+			Scopes: []string{"openid", "email"},
+		},
+		Tenant:   tenant,
+		UserFlow: userFlow,
+	}
+}
+
+func (p *AzureADB2CProvider) SetHttpClient(client *http.Client) {
+	p.Client = client
+}
+
+type AzureadB2cToken struct {
+	IdToken          string `json:"id_token"`
+	TokenType        string `json:"token_type"`
+	NotBefore        int    `json:"not_before"`
+	IdTokenExpiresIn int    `json:"id_token_expires_in"`
+	ProfileInfo      string `json:"profile_info"`
+	Scope            string `json:"scope"`
+}
+
+func (p *AzureADB2CProvider) GetToken(code string) (*oauth2.Token, error) {
+	payload := url.Values{}
+	payload.Set("code", code)
+	payload.Set("grant_type", "authorization_code")
+	payload.Set("client_id", p.Config.ClientID)
+	payload.Set("client_secret", p.Config.ClientSecret)
+	payload.Set("redirect_uri", p.Config.RedirectURL)
+
+	resp, err := p.Client.PostForm(p.Config.Endpoint.TokenURL, payload)
+	if err != nil {
+		return nil, err
+	}
+
+	data, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	pToken := &AzureadB2cToken{}
+	err = json.Unmarshal(data, pToken)
+	if err != nil {
+		return nil, err
+	}
+
+	token := &oauth2.Token{
+		AccessToken: pToken.IdToken,
+		Expiry:      time.Unix(time.Now().Unix()+int64(pToken.IdTokenExpiresIn), 0),
+	}
+	return token, nil
+}
+
+func (p *AzureADB2CProvider) GetUserInfo(token *oauth2.Token) (*UserInfo, error) {
+	userInfoEndpoint := fmt.Sprintf("https://%s.b2clogin.com/%s.onmicrosoft.com/%s/openid/v2.0/userinfo", p.Tenant, p.Tenant, p.UserFlow)
+	req, err := http.NewRequest("GET", userInfoEndpoint, nil)
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Add("Authorization", "Bearer "+token.AccessToken)
+
+	resp, err := p.Client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("error fetching user info: status code %d", resp.StatusCode)
+	}
+
+	bodyBytes, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	var userInfo UserInfo
+	err = json.Unmarshal(bodyBytes, &userInfo)
+	if err != nil {
+		return nil, err
+	}
+
+	return &userInfo, nil
+}