使用smtp.Gmail.com:857在C#中使用SmtpClient，并激活了Google的两步验证 [英] SmtpClient in C# using smtp.Gmail.com:857 with Google's 2 Step Verification activated
问题描述
我在使用C#中的Gmail SMTP服务器发送电子邮件时遇到了麻烦.在StackOverflow中有很多关于此问题的主题，但是周围的解决方案都无法满足我的要求.
I'm having trouble with sending an email using the Gmail SMTP Server in C#. There is plenty of subjects about this matter in StackOverflow, but none of the solutions around there are working with my specifities.
我的专长是:
- 生成了应用专用密码"，原本的密码很强 由于其他一些应用，
- 双重身份验证(两步验证)已激活，并且必须 在Google的用户界面中，
- 允许安全程度较低的应用程序"参数不可用
- App Specific Password generated and very strong password originally
- Double Auth (2 Step Verification) activated and required because of some other app
- "Allow Less Secure Apps" parameter is unavailable from Google's UI
有人可以提出解决方案吗? 我们正在寻找一种尊重主账户完整性的解决方案，因此禁用两步验证"解决方案不是有效的解决方案.
Can someone propose a solution ? The solution "Disable 2 Step Verification" is not a valid solution are we are looking for a solution that respects main account integrity.
也许有使用Google API或任何其他配置参数的解决方案?我怀疑是否存在面向C#的解决方案，因为两步验证"旨在提供一个更安全的帐户，但是特定于应用程序的密码"不是一种绕过某些应用程序的两步验证"的方法吗?
Maybe there is a solution using Google's API or any other config parameter ? I doubt there is a C# oriented solution as 2 Step Verification is intended to provide a more secure account, but isn't the "App Specific Password" a way to bypass the 2 Step Verification for some app ?
我已经生成了特定的应用密码: https://security.google.com/settings /security/apppasswords
I have generated a specific app password : https://security.google.com/settings/security/apppasswords
缺少安全应用程序"参数不可用: https://www.google.com/settings /security/lesssecureapps
Less Secure Apps parameter is not available : https://www.google.com/settings/security/lesssecureapps
这是我的代码:
public string sendEmailUsingGmail(string email)
{
using (MailMessage mail = new MailMessage("from_account@gmail.com", email)
{
Subject = "Aquaponey today",
Body = "Hello, you are a Unicorn and you will be late for aquaponey today. - God",
IsBodyHtml = true,
Priority = System.Net.Mail.MailPriority.High
})
{
using (SmtpClient smtpClient = new SmtpClient("smtp.gmail.com", 587))
{
smtpClient.Credentials = new System.Net.NetworkCredential()
{
UserName = "my_account@gmail.com",
Password = @"my_specific_app_password"
};
smtpClient.EnableSsl = true;
System.Net.ServicePointManager.ServerCertificateValidationCallback = delegate (object s,
System.Security.Cryptography.X509Certificates.X509Certificate certificate,
System.Security.Cryptography.X509Certificates.X509Chain chain,
System.Net.Security.SslPolicyErrors sslPolicyErrors)
{
return true;
};
smtpClient.Send(mail);
return "OK";
}
}
}
我的客户返回的错误是:
The error returned by my client is :
System.Net.Mail.SmtpException:5.5.1需要身份验证.进一步了解
System.Net.Mail.SmtpException: 5.5.1 Authentication Required. Learn more at
推荐答案
我以前尝试过使用Google API进行邮件发送.我的理解是，您必须建立一个登录名(这将触发两步)，这将为您提供一个开放的会话.然后，通过该开放会话，您可以发送邮件.否则，代码很可能在等待登录的后半部分时超时.
I've tried to work with the Google API for mail sending before. My understanding is that you have to establish a login (Which will trigger the two step) which provides you with an open session. And then with that open session you can send the mail. Otherwise most likely the code is timing out while waiting for the second half of the login.
更新:您可以使用服务器端身份验证过程，这将需要最终用户一次登录(这将需要通过两因素身份验证进行登录)，并且将为您提供刷新令牌可以用来重新连接到服务器.该信息位于Google Developers Docs
Update: You can use the Server Side Authentication process, this will require a one time sign in from the end user (Which will have to go through the sign in with two factor authentication) and that will provide you with a refresh token that can use to re-connect to the server. The information is located at the Google Developers Docs
以下摘录
实施服务器端授权
Implementing Server-Side Authorization
对Gmail API的请求必须使用OAuth 2.0授权 证书.您的应用程序应使用服务器端流程 需要代表用户访问Google API，例如 用户处于离线状态.这种方法需要一次性通过 从客户端到服务器的授权码；该代码被使用 获取访问令牌并刷新服务器的令牌.
Requests to the Gmail API must be authorized using OAuth 2.0 credentials. You should use server-side flow when your application needs to access Google APIs on behalf of the user, for example when the user is offline. This approach requires passing a one-time authorization code from your client to your server; this code is used to acquire an access token and refresh tokens for your server.
下面也是该站点的示例python代码(我知道您正在使用C#)
Below is also the sample python code from the site (I know you're using C#)
将CLIENTSECRETS_LOCATION值替换为client_secrets.json文件的位置.
Replace CLIENTSECRETS_LOCATION value with the location of your client_secrets.json file.
import logging
from oauth2client.client import flow_from_clientsecrets
from oauth2client.client import FlowExchangeError
from apiclient.discovery import build
# ...
# Path to client_secrets.json which should contain a JSON document such as:
# {
# "web": {
# "client_id": "[[YOUR_CLIENT_ID]]",
# "client_secret": "[[YOUR_CLIENT_SECRET]]",
# "redirect_uris": [],
# "auth_uri": "https://accounts.google.com/o/oauth2/auth",
# "token_uri": "https://accounts.google.com/o/oauth2/token"
# }
# }
CLIENTSECRETS_LOCATION = '<PATH/TO/CLIENT_SECRETS.JSON>'
REDIRECT_URI = '<YOUR_REGISTERED_REDIRECT_URI>'
SCOPES = [
'https://www.googleapis.com/auth/gmail.readonly',
'https://www.googleapis.com/auth/userinfo.email',
'https://www.googleapis.com/auth/userinfo.profile',
# Add other requested scopes.
]
class GetCredentialsException(Exception):
"""Error raised when an error occurred while retrieving credentials.
Attributes:
authorization_url: Authorization URL to redirect the user to in order to
request offline access.
"""
def __init__(self, authorization_url):
"""Construct a GetCredentialsException."""
self.authorization_url = authorization_url
class CodeExchangeException(GetCredentialsException):
"""Error raised when a code exchange has failed."""
class NoRefreshTokenException(GetCredentialsException):
"""Error raised when no refresh token has been found."""
class NoUserIdException(Exception):
"""Error raised when no user ID could be retrieved."""
def get_stored_credentials(user_id):
"""Retrieved stored credentials for the provided user ID.
Args:
user_id: User's ID.
Returns:
Stored oauth2client.client.OAuth2Credentials if found, None otherwise.
Raises:
NotImplemented: This function has not been implemented.
"""
# TODO: Implement this function to work with your database.
# To instantiate an OAuth2Credentials instance from a Json
# representation, use the oauth2client.client.Credentials.new_from_json
# class method.
raise NotImplementedError()
def store_credentials(user_id, credentials):
"""Store OAuth 2.0 credentials in the application's database.
This function stores the provided OAuth 2.0 credentials using the user ID as
key.
Args:
user_id: User's ID.
credentials: OAuth 2.0 credentials to store.
Raises:
NotImplemented: This function has not been implemented.
"""
# TODO: Implement this function to work with your database.
# To retrieve a Json representation of the credentials instance, call the
# credentials.to_json() method.
raise NotImplementedError()
def exchange_code(authorization_code):
"""Exchange an authorization code for OAuth 2.0 credentials.
Args:
authorization_code: Authorization code to exchange for OAuth 2.0
credentials.
Returns:
oauth2client.client.OAuth2Credentials instance.
Raises:
CodeExchangeException: an error occurred.
"""
flow = flow_from_clientsecrets(CLIENTSECRETS_LOCATION, ' '.join(SCOPES))
flow.redirect_uri = REDIRECT_URI
try:
credentials = flow.step2_exchange(authorization_code)
return credentials
except FlowExchangeError, error:
logging.error('An error occurred: %s', error)
raise CodeExchangeException(None)
def get_user_info(credentials):
"""Send a request to the UserInfo API to retrieve the user's information.
Args:
credentials: oauth2client.client.OAuth2Credentials instance to authorize the
request.
Returns:
User information as a dict.
"""
user_info_service = build(
serviceName='oauth2', version='v2',
http=credentials.authorize(httplib2.Http()))
user_info = None
try:
user_info = user_info_service.userinfo().get().execute()
except errors.HttpError, e:
logging.error('An error occurred: %s', e)
if user_info and user_info.get('id'):
return user_info
else:
raise NoUserIdException()
def get_authorization_url(email_address, state):
"""Retrieve the authorization URL.
Args:
email_address: User's e-mail address.
state: State for the authorization URL.
Returns:
Authorization URL to redirect the user to.
"""
flow = flow_from_clientsecrets(CLIENTSECRETS_LOCATION, ' '.join(SCOPES))
flow.params['access_type'] = 'offline'
flow.params['approval_prompt'] = 'force'
flow.params['user_id'] = email_address
flow.params['state'] = state
return flow.step1_get_authorize_url(REDIRECT_URI)
def get_credentials(authorization_code, state):
"""Retrieve credentials using the provided authorization code.
This function exchanges the authorization code for an access token and queries
the UserInfo API to retrieve the user's e-mail address.
If a refresh token has been retrieved along with an access token, it is stored
in the application database using the user's e-mail address as key.
If no refresh token has been retrieved, the function checks in the application
database for one and returns it if found or raises a NoRefreshTokenException
with the authorization URL to redirect the user to.
Args:
authorization_code: Authorization code to use to retrieve an access token.
state: State to set to the authorization URL in case of error.
Returns:
oauth2client.client.OAuth2Credentials instance containing an access and
refresh token.
Raises:
CodeExchangeError: Could not exchange the authorization code.
NoRefreshTokenException: No refresh token could be retrieved from the
available sources.
"""
email_address = ''
try:
credentials = exchange_code(authorization_code)
user_info = get_user_info(credentials)
email_address = user_info.get('email')
user_id = user_info.get('id')
if credentials.refresh_token is not None:
store_credentials(user_id, credentials)
return credentials
else:
credentials = get_stored_credentials(user_id)
if credentials and credentials.refresh_token is not None:
return credentials
except CodeExchangeException, error:
logging.error('An error occurred during code exchange.')
# Drive apps should try to retrieve the user and credentials for the current
# session.
# If none is available, redirect the user to the authorization URL.
error.authorization_url = get_authorization_url(email_address, state)
raise error
except NoUserIdException:
logging.error('No user ID could be retrieved.')
# No refresh token has been retrieved.
authorization_url = get_authorization_url(email_address, state)
raise NoRefreshTokenException(authorization_url)
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