Home > Articles

Policy-Based Decryption (Lesson 6 transcript from Upgrading to Red Hat Enterprise Linux (RHEL) 8 LiveLessons)

In Lesson 6, Sander van Vugt explains policy-based decryption. Read the transcript below.

From the Video

Lesson 6 Introduction

Hi, welcome to lesson six. In this lesson you'll learn how to work with LUKS encryption. While LUKS encryption itself is not new, the option to enable access to LUKS encrypted devices by authorizing to a network server is new. In this lesson, you'll learn how to work with it.

Setting up LUKS

So, this lesson is about policy-based decryption. Policy-based decryption is used for LUKS. LUKS are encrypted devices. An inconvenience is that in order to use a LUKS-encrypted device, you need to enter a passphrase. And that's why we want to use policy-based decryption. But before you can do that, you need to set up a LUKS device. On the slide I have summarized a procedure and I'm going to demonstrate how to apply this procedure. So, before we can create an encrypted device we need a block device.

So let me start at lsblk to list current block devices. And we can see that there's a disc nvme0n2. I'm going to use that c encrypted device. In order to do so, I'm using cryptsetup luksformat on dev nvme0n2. We can see that this device has been used for something else previously. I don't care, I'm going to override it. So I say, yes.

Next it is asking for a passphrase. This passphrase needs to be reasonable complex and it needs to be used while accessing the encrypted device. At this point I have created the cryptographic layer on top of the LUKS device. So let's first verify that we can open it. In order to do so I'm using cryptsetup luksOpen followed by the name of the device. Followed by the name of an encrypted device that needs to be created. So the secret in here is a new device that will be created, after I have entered the passphrase. And that is exactly what is wrong with this procedure. Encrypted devices are very nice, but if you use them on the server, you don't want manual interaction to enter a passphrase, but for now we don't have any choice. So by using the cryptsetup luksOpen, I have opened the encrypted device. And we should see the results in the dev mapper directory. What I'm looking for is this. Here we can see the secret device that has been created in dev/mapper and that's the opened encrypted device. In order to do something with it I need to put a file system on top. So mkfs.xfs on dev mapper secret will do that for me. And now I must make sure that I can mount it, so let me create the directory and next use mount of dev mapper secret on /secret. And at this point it is working. If I want to automate this and automatically start the encrypted device while booting then I need to create the file etc crypttab. So in etc/crypttab I need to specify the name of the file that needs to be created. That will be secret. Then I need to specify the name of the underlying device, that is nvme0n2.

Next I'm using none. The none indicates that I don't want to feed a passphrase through this configuration file and I need _netdev. _netdev is a mandatory option if you want to automate this procedure later on. So this part will make sure that the encrypted device is opened while booting, but it doesn't mount it. In order to mount it, I also need to edit etc fstab. So what are we going to do in etc fstab, well we are going to use dev mapper secret which is the name of the opened encrypted device we mounted on /secret. We set the file system to xsf and we need the mount option netdev and then we include 00 which is quite common as mount options. That should do it so at this point if I reboot the encrypted device should be initialized. Let's have a look. So this is what happens. You can see that I am prompted to enter the passphrase at this point. And even if that works, that isn't convenient at all and that is why we have policy-based decryption, which we will talk about next.

Pearson IT Certification Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from Pearson IT Certification and its family of brands. I can unsubscribe at any time.

Overview


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about Pearson IT Certification products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information


To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites; develop new products and services; conduct educational research; and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information


Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children


This site is not directed to children under the age of 13.

Marketing


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information


If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out


Users can always make an informed choice as to whether they should proceed with certain services offered by Adobe Press. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.pearsonitcertification.com/u.aspx.

Sale of Personal Information


Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents


California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure


Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact


Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice


We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020