brief introduction
When we visit the website, we will deal with all kinds of certificates , Like visiting https On the web , Need to detect https Certificate validity of the website .
OCSP Is a verification protocol , Used to get X.509 Revocation status of digital certificate . It is to replace CRL And the emergence of .
This article will introduce in detail OCSP Implementation and advantages of .
PKI Medium CRL
We know that PKI Architecture ,CA Certificates are a very important component , Client pass CA Certificate to verify the reliability of the service . about CA For the certificate itself, the expiration time can be specified when it is created . In this way, the certificate can not be used after expiration , Need to apply for a new certificate .
However, it is not enough to specify the expiration time for the certificate , For example, because of our business needs , What if the certificate needs to be revoked ？
PKI There is one provided in called CRL(certificate revocation list) The mechanism of , Used to maintain the list of revoked certificates .
This CRL By CA To issue , It is usually generated before the certificate expires . Because if the certificate has expired , So this CRL It's meaningless .
about CRL itself , It is a list of certificates , The format of the certificate is usually X.509.
CRL Generally, the certificate is issued by CA To maintain and publish , Release CRL The component is called CRL issuer, Generally speaking CRL issuer and CA It's the same service , But you can also send... As needed CRL issuer and CA To break up .
CRL By CA Regularly released , Of course, you can also revoke a as needed CA Reissue the certificate when CRL. be-all CRL All have expiration dates , Within this expiration time , The client can be based on CRL Signature in , Go to CA verification CRL The effectiveness of the , To prevent CRL Forgery of .
CRL The shortcomings of
that CRL What are the disadvantages ？
First CRL Maintain a list of revoked certificates , In order to ensure the effectiveness of the system , The client checks every time CA When the certificate is valid , From the CA Get this from the server CRL. And then through CRL To verify the corresponding CA Certificate Status .
If you get this every time CRL, There may be the following problems .
The first question is , If CRL Unavailable , Then the client can't get this CRL, You can't verify CA The status of the certificate , This makes the service unavailable .
Another problem is , If there are many certificates to revoke , This CRL It may be relatively large , Thus causing a waste of network resources .
The last question is PKI The purpose of certificate system itself is to establish a self verifiable , A security system that does not rely on online services , If you have to get it online every time CRL Words , Just go PKI This advantage of .
CRL The state of
although CRL Maintain a list of revocation certificates , However, the status of certificates in this list is different .
CRL There are two statuses of certificates in , The first is that the certificate has been revoked , For example, the certification authority CA It is found that the previously issued certificate is wrong , Or because of other reasons, such as the disclosure of the private key, the original certificate is not secure enough , The certificate needs to be withdrawn . Or the certificate authority's certificate is revoked because it fails to comply with some policies , You need to set the previous certificate to revocation status .
There is also a state of temporary revocation , It's called Hold state , The certificate is temporarily invalid , For example, determine whether the user's private key is lost . When the user finally finds the private key , Then the certificate can still be restored .
OCSP workflow
since CRL There are so many shortcomings , So one is used to replace CRL Of OCSP There's an agreement .
So let's see OCSP workflow .
If A and B To use PKI To communicate . In order to ensure the security of communication ,A Send your public key to B, And tell B, This is my public key , You can use this public key to verify the message I sent you .
B Upon receipt of A After the public key of , I'm not sure A Your public key is correct , Not tampered with . So from the A Extracted from the public key of serial number, And encapsulate it into a 'OCSP request' Medium distribution CA The server .
CA In the server OCSP responder It reads 'OCSP request' request , And extract A Of the public key serial number.OCSP responder from CA Query this in the database of the server serial number Whether it is in the list of revoked databases .
If it's not found , That means A Your public key is still valid ,OCSP responder A signed... Will be sent OCSP response to B.
B By using CA Public key verification of the server OCSP response The effectiveness of the , So as to confirm A Your public key is still valid .
Last B Use A The public key and A To communicate .
OCSP The advantages of
From the above OCSP We can roughly summarize the following work flow OCSP be relative to CRL The advantages of .
First OCSP The amount of data in response is greater than CRL smaller , So there is less demand and pressure on the network .
In addition, because OCSP The response has less data to parse , therefore OCSP The implementation of the client is better than CRL It's simpler .
Although because of CRL All kinds of shortcomings , stay web No longer used in the environment , But by being more efficient OCSP Replace , however CRL Still running in CA In other environments .
OCSP Details of the agreement
OCSP The agreement is in RFC 6960 As defined in .
OCSP The protocol can be divided into request protocol and response protocol , Next, let's introduce .
OCSP request
One OCSP The request needs to contain the protocol version number , Request service , Certificate to be verified identifier And optional extensions .
OCSP responder On receiving OCSP After the request , It's going to check OCSP The validity of the message , If there is a problem with the message, an exception will be returned , Otherwise, it will be processed according to the requested service .
OCSP Request if ASN.1(Abstract Syntax Notation One) Abstract syntax notation this can be expressed as ：
OCSPRequest ::= SEQUENCE {
tbsRequest TBSRequest,
optionalSignature [0] EXPLICIT Signature OPTIONAL }
TBSRequest ::= SEQUENCE {
version [0] EXPLICIT Version DEFAULT v1,
requestorName [1] EXPLICIT GeneralName OPTIONAL,
requestList SEQUENCE OF Request,
requestExtensions [2] EXPLICIT Extensions OPTIONAL }
Signature ::= SEQUENCE {
signatureAlgorithm AlgorithmIdentifier,
signature BIT STRING,
certs [0] EXPLICIT SEQUENCE OF Certificate OPTIONAL}
Version ::= INTEGER { v1(0) }
Request ::= SEQUENCE {
reqCert CertID,
singleRequestExtensions [0] EXPLICIT Extensions OPTIONAL }
CertID ::= SEQUENCE {
hashAlgorithm AlgorithmIdentifier,
issuerNameHash OCTET STRING, -- Hash of issuer's DN
issuerKeyHash OCTET STRING, -- Hash of issuer's public key
serialNumber CertificateSerialNumber }
ASN.1 Is an interface description language , adopt ASN.1, We can clearly describe the format information of data .
One OCSPRequest Is optionally signed by OCSP request tbsRequest And the corresponding signature optionalSignature Composed of .
among TBSRequest It contains the version number ,OCSP requestor Name , Status list of certificates requestList, The optional extended data consists of these items .
OCSP Respond to
about OCSP In terms of response , According to different transmission protocols, its structure is also different . But all responses should contain responseStatus Field indicates the processing status of the request .
OCSP Sound application ASN.1 The format is represented as follows ：
OCSPResponse ::= SEQUENCE {
responseStatus OCSPResponseStatus,
responseBytes [0] EXPLICIT ResponseBytes OPTIONAL }
OCSPResponseStatus ::= ENUMERATED {
successful (0), -- Response has valid confirmations
malformedRequest (1), -- Illegal confirmation request
internalError (2), -- Internal error in issuer
tryLater (3), -- Try again later
-- (4) is not used
sigRequired (5), -- Must sign the request
unauthorized (6) -- Request unauthorized
}
ResponseBytes ::= SEQUENCE {
responseType OBJECT IDENTIFIER,
response OCTET STRING }
responseStatus Is the status of the response ,responseBytes Is an optional response result .
there response It's a BasicOCSPResponse Object's DER code ：
BasicOCSPResponse ::= SEQUENCE {
tbsResponseData ResponseData,
signatureAlgorithm AlgorithmIdentifier,
signature BIT STRING,
certs [0] EXPLICIT SEQUENCE OF Certificate OPTIONAL }
OCSP stapling
You can see OCSP When the customer needs to check whether the certificate is revoked , You need to OCSP responser request , To confirm the validity of the certificate .
But this method actually divulges the user's private information , because OCSP responser Know the certificate that the client needs to verify , Just know the website the client is visiting .
So I introduced OCSP stapling To solve this problem .
So what is OCSP stapling Well ?
OCSP stapling Is directly to the OCSP Put the certificate in the place that the client wants to access web Server , because OCSP Certificates are time stamped and digitally signed , Therefore, its correctness can be guaranteed .
these OCSP The certificate will be displayed on the client and web End build SSL The handshake is included in OCSP Response .
In this way, the client does not need to be separated from CA Establish additional connections , This improves performance .
OCSP stapling It needs to be started on the server side .
If you're using a apache The server , First, you need a version greater than 2.3.3.
Then it needs to be in .conf In the document <VirtualHost></VirtualHost> block External addition ：
SSLStaplingCahe shmcb: /tmp/stapling_cache(128000)
And then in <VirtualHost></VirtualHost> block Add... Inside of ：
SSLUseStapling On
If you're using a nginx, First, you need a version greater than 1.3.7.
And then in nginx Configuration file for server {} block Add ：
ssl_stapling on;
ssl_stapling_verify on;
If you want to verify whether a website is open OCSP stapling, You can go to https://entrust.ssllabs.com/ Query in the website ：
In this website , You can enter the address of any website you want to query , Then you can get the following information ：
You can see that this website is open OCSP stapling Of .
summary
OCSP and OCSP stapling Is a very useful certificate revocation verification protocol , Has been widely used . You can check whether your website is used .
Please refer to http://www.flydean.com/43-pki-ocsp/
The most popular interpretation , The deepest dry goods , The most concise tutorial , There are so many tricks you don't know about waiting for you to discover ！
Welcome to my official account. :「 Program those things 」, Know technology , Know you better ！
Cryptography series : Online Certificate Status Protocol OCSP More related articles in detail
- [ Re posting ] Technical literacy ： The new generation is based on UDP Low latency network transport layer protocol ——QUIC Detailed explanation
Technical literacy : The new generation is based on UDP Low latency network transport layer protocol ——QUIC Detailed explanation http://www.52im.net/thread-1309-1-1.html This article is from the technology sharing of Luo Cheng, senior R & D Engineer of Tencent , ...
- Protocol analysis － DHCP Protocol decoding details
Protocol analysis - DHCP Protocol decoding details [DHCP Protocol Brief ] DHCP, The full name is Dynamic Host Configuration Protocol﹐ The Chinese name is dynamic host configuration protocol , Its predecessor is ...
- Memcache Use and protocol analysis of
Memcache Use and protocol analysis of author :heiyeluren Blog :http://blog.csdn.NET/heiyeshuwu Time :2006-11-12 keyword :PHP Memcache Linu ...
- Online learning algorithms widely used by major companies FTRL Detailed explanation
Online learning algorithms widely used by major companies FTRL Detailed explanation Now do online learning and CTR Logical regression is often used ( Logistic Regression), And the traditional batch (batch) The algorithm can't deal with large-scale data sets and online data effectively ...
- Master Dubbo——Dubbo Details of supported protocols
turn : Master Dubbo——Dubbo Details of supported protocols 2017 year 06 month 02 Japan 22:26:57 Grandchildren _ enlightenment _ empty Read the number :44500 Dubbo Support dubbo.rmi.hessian.http.webse ...
- Java 8 Series of Stream A detailed explanation of the basic grammar of
This article goes to :https://blog.csdn.net/io_field/article/details/54971761 Stream series : Java 8 Series of Stream A detailed explanation of the basic grammar of Java 8 ...
- OSGi series （ 3、 ... and ） And bundle Detailed explanation
OSGi series ( 3、 ... and ) And bundle Detailed explanation 1. What is? bundle bundle In order to jar A modular physical unit in the form of a package , It contains the code , Resource files and metadata (metadata), also jar ...
- Python operation redis Series with Hash (Hash) Detailed command （ Four ）
# -*- coding: utf-8 -*- import redis # This redis Out-of-service , Please modify it according to your own needs r =redis.Redis(host=") 1. Hset The command is used for ...
- （ summary ）Linux Violent password online cracking tool under Hydra Detailed explanation
( summary )Linux Violent password online cracking tool under Hydra Detailed explanation To study the :https://blog.csdn.net/yafeichang/article/details/53502869
- HTTP Details of the agreement
[HTTP Details of the agreement ] Ø Request part * Request line * submission : * There are many ways to submit , frequently-used GET and POST: * GET and POST The difference between : * GET The submitted parameters of will be displayed in the address bar , and POST No display . ...
Random recommendation
- WKWebView elementary analysis
Link to the original text :supermokey WKWebView One WKWebView Objects show interactive web Content , For example, apply to app Browser in . You can be in your App Use in WKWebView. review Important: ...
- JqGrid Custom columns
$("#gridTable").jqGrid({ //... Other attributes colModel: [ //... Other columns { name: 'dsource_alarm', index: 'd ...
- 【MVC 4】4.MVC Basic tools （Visual Studio Unit test 、 Use Moq）
author :[ beautiful ]Adam Freeman source :< Master ASP.NET MVC 4> 3.Visual Studio Unit test There's a lot of .NET Unit test package , Many of them are open source and free . Ben ...
- The programmer " Youth meal " My opinion on the problem
The programmer " Youth meal " My opinion on the problem Statement : Reprint please indicate the source .http://www.cnblogs.com/hzg1981/ 1. Problem description problem 1: What is a programmer ? In this article, the definition of programmer ...
- turn ：Maven Introduce ( Create engineering projects and download what you need jar package )
http://blog.csdn.net/guanghua2009/article/details/6644111 At present, I'm not very good at using maven, Learn slowly At present, it is used to download what you want jar package , First, according to this article ...
- Gradle User manual （ 3、 ... and ）： Build tasks
Original address :http://tools.android.com/tech-docs/new-build-system/user-guide#TOC-Using-sourceCompatibility-1. ...
- C++ Programming learning 52 A classic website Strongly recommend
C/C++ Is the main programming language . Here's a list 50 List of excellent websites and pages , These sites offer c/c++ Source code . This list provides links to the source code and their novels . I've tried to include the best C/C++ Source code website . This is not a complete Qing Dynasty ...
- C++ Design pattern video explanation
Design patterns (C++) Video website : http://www.qghkt.com/ Design patterns (C++) Video address : https://ke.qq.com/course/318637?tuin=a508ea62 Objective ...
- python Learning of encryption algorithm and its related modules （hashlib,random,string,math）
Encryption algorithm One ,HASH Hash, General translation “ hash ”, There are also direct transliteration for ” Hash ” Of , I'm just taking the input of any length ( It's also called pre mapping ,pre-image), By the hash algorithm , To a fixed length output , The output is the hash value . such ...
- C# sketch （ Two ）
Please refer to :http://www.runoob.com/csharp/csharp-operators.html 1.C# Operator Arithmetic operator Relational operator Logical operators An operator Assignment operator Other operators ...
![[tools] basic concept of database and MySQL installation](/img/9c/626e42097050517a13a2ce7cdab1bb.jpg)