feat: support acs email provider (#2323)

* feat: support acs email provider

* feat: support acs email provider

* hide Test SMTP Connection button

* fix name acs

email/azure_acs.go

@@ -0,0 +1,227 @@
+// 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 email
+
+import (
+	"bytes"
+	"crypto/hmac"
+	"crypto/sha256"
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/google/uuid"
+)
+
+const (
+	importanceNormal  = "normal"
+	sendEmailEndpoint = "/emails:send"
+	apiVersion        = "2023-03-31"
+)
+
+type Email struct {
+	Recipients    Recipients     `json:"recipients"`
+	SenderAddress string         `json:"senderAddress"`
+	Content       Content        `json:"content"`
+	Headers       []CustomHeader `json:"headers"`
+	Tracking      bool           `json:"disableUserEngagementTracking"`
+	Importance    string         `json:"importance"`
+	ReplyTo       []EmailAddress `json:"replyTo"`
+	Attachments   []Attachment   `json:"attachments"`
+}
+
+type Recipients struct {
+	To  []EmailAddress `json:"to"`
+	CC  []EmailAddress `json:"cc"`
+	BCC []EmailAddress `json:"bcc"`
+}
+
+type EmailAddress struct {
+	DisplayName string `json:"displayName"`
+	Address     string `json:"address"`
+}
+
+type Content struct {
+	Subject   string `json:"subject"`
+	HTML      string `json:"html"`
+	PlainText string `json:"plainText"`
+}
+
+type CustomHeader struct {
+	Name  string `json:"name"`
+	Value string `json:"value"`
+}
+
+type Attachment struct {
+	Content        string `json:"contentBytesBase64"`
+	AttachmentType string `json:"attachmentType"`
+	Name           string `json:"name"`
+}
+
+type ErrorResponse struct {
+	Error CommunicationError `json:"error"`
+}
+
+// CommunicationError contains the error code and message
+type CommunicationError struct {
+	Code    string `json:"code"`
+	Message string `json:"message"`
+}
+
+type AzureACSEmailProvider struct {
+	AccessKey string
+	Endpoint  string
+}
+
+func NewAzureACSEmailProvider(accessKey string, endpoint string) *AzureACSEmailProvider {
+	return &AzureACSEmailProvider{
+		AccessKey: accessKey,
+		Endpoint:  endpoint,
+	}
+}
+
+func newEmail(fromAddress string, toAddress string, subject string, content string) *Email {
+	return &Email{
+		Recipients: Recipients{
+			To: []EmailAddress{
+				{
+					DisplayName: toAddress,
+					Address:     toAddress,
+				},
+			},
+		},
+		SenderAddress: fromAddress,
+		Content: Content{
+			Subject: subject,
+			HTML:    content,
+		},
+		Importance: importanceNormal,
+	}
+}
+
+func (a *AzureACSEmailProvider) sendEmail(e *Email) error {
+	postBody, err := json.Marshal(e)
+	if err != nil {
+		return fmt.Errorf("email JSON marshall failed: %s", err)
+	}
+
+	bodyBuffer := bytes.NewBuffer(postBody)
+
+	req, err := http.NewRequest("POST", a.Endpoint+sendEmailEndpoint+"?api-version="+apiVersion, bodyBuffer)
+	if err != nil {
+		return fmt.Errorf("error creating AzureACS API request: %s", err)
+	}
+
+	// Sign the request using the AzureACS access key and HMAC-SHA256
+	err = signRequestHMAC(a.AccessKey, req)
+	if err != nil {
+		return fmt.Errorf("error signing AzureACS API request: %s", err)
+	}
+
+	req.Header.Set("Content-Type", "application/json")
+
+	// Some important header
+	req.Header.Set("repeatability-request-id", uuid.New().String())
+	req.Header.Set("repeatability-first-sent", time.Now().UTC().Format(http.TimeFormat))
+
+	// Send request
+	client := &http.Client{}
+	resp, err := client.Do(req)
+	if err != nil {
+		return fmt.Errorf("error sending AzureACS API request: %s", err)
+	}
+	defer resp.Body.Close()
+
+	// Response error Handling
+	if resp.StatusCode == http.StatusBadRequest {
+		commError := ErrorResponse{}
+
+		err = json.NewDecoder(resp.Body).Decode(&commError)
+		if err != nil {
+			return err
+		}
+
+		return fmt.Errorf("error sending email: %s", commError.Error.Message)
+	}
+
+	if resp.StatusCode != http.StatusAccepted {
+		return fmt.Errorf("error sending email: status: %d", resp.StatusCode)
+	}
+
+	return nil
+}
+
+func signRequestHMAC(secret string, req *http.Request) error {
+	method := req.Method
+	host := req.URL.Host
+	pathAndQuery := req.URL.Path
+
+	if req.URL.RawQuery != "" {
+		pathAndQuery = pathAndQuery + "?" + req.URL.RawQuery
+	}
+
+	var content []byte
+	var err error
+	if req.Body != nil {
+		content, err = io.ReadAll(req.Body)
+		if err != nil {
+			// return err
+			content = []byte{}
+		}
+	}
+
+	req.Body = io.NopCloser(bytes.NewBuffer(content))
+
+	key, err := base64.StdEncoding.DecodeString(secret)
+	if err != nil {
+		return fmt.Errorf("error decoding secret: %s", err)
+	}
+
+	timestamp := time.Now().UTC().Format(http.TimeFormat)
+	contentHash := GetContentHashBase64(content)
+	stringToSign := fmt.Sprintf("%s\n%s\n%s;%s;%s", strings.ToUpper(method), pathAndQuery, timestamp, host, contentHash)
+	signature := GetHmac(stringToSign, key)
+
+	req.Header.Set("x-ms-content-sha256", contentHash)
+	req.Header.Set("x-ms-date", timestamp)
+
+	req.Header.Set("Authorization", "HMAC-SHA256 SignedHeaders=x-ms-date;host;x-ms-content-sha256&Signature="+signature)
+
+	return nil
+}
+
+func GetContentHashBase64(content []byte) string {
+	hasher := sha256.New()
+	hasher.Write(content)
+
+	return base64.StdEncoding.EncodeToString(hasher.Sum(nil))
+}
+
+func GetHmac(content string, key []byte) string {
+	hmac := hmac.New(sha256.New, key)
+	hmac.Write([]byte(content))
+
+	return base64.StdEncoding.EncodeToString(hmac.Sum(nil))
+}
+
+func (a *AzureACSEmailProvider) Send(fromAddress string, fromName string, toAddress string, subject string, content string) error {
+	e := newEmail(fromAddress, toAddress, subject, content)
+
+	return a.sendEmail(e)
+}