This topic provides step-by-step instructions for setting up SSL/TLS offload with AWS CloudHSM on a Linux web server.
Topics
Overview
On Linux, the NGINX
To complete this tutorial, you must first choose whether to use the NGINX or Apache web server software on Linux. Then the tutorial shows you how to do the following:
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Install the web server software on an Amazon EC2 instance.
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Configure the web server software to support HTTPS with a private key stored in your AWS CloudHSM cluster.
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(Optional) Use Amazon EC2 to create a second web server instance and Elastic Load Balancing to create a load balancer. Using a load balancer can increase performance by distributing the load across multiple servers. It can also provide redundancy and higher availability if one or more servers fail.
When you're ready to get started, go to Step 1: Set up the prerequisites.
Step 1: Set up the prerequisites
Different platforms require different prerequisites. Use the prerequisites section below that matches your platform.
Prerequisites for Client SDK 5
To set up web server SSL/TLS offload with Client SDK 5, you need the following:
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An active AWS CloudHSM cluster with at least two hardware security modules (HSM)
Note
You can use a single HSM cluster, but you must first disable client key durability. For more information, see Manage Client Key Durability Settings and Client SDK 5 Configure Tool.
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An Amazon EC2 instance running a Linux operating system with the following software installed:
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A web server (either NGINX or Apache)
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The OpenSSL Dynamic Engine for Client SDK 5
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A crypto user (CU) to own and manage the web server's private key on the HSM.
To set up a Linux web server instance and create a CU on the HSM
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Install and configure the OpenSSL Dynamic Engine for AWS CloudHSM. For more information about installing OpenSSL Dynamic Engine, see OpenSSL Dynamic Engine for Client SDK 5.
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On an EC2 Linux instance that has access to your cluster, install either NGINX or Apache web server:
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NGINX
$sudo yum install nginx -
Apache
$sudo yum install httpd24 mod24_ssl
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Use CloudHSM CLI to create a crypto user. For more information about managing HSM users, see Managing HSM users with CloudHSM CLI.
Tip
Keep track of the CU user name and password. You will need them later when you generate or import the HTTPS private key and certificate for your web server.
After you complete these steps, go to Step 2: Generate the private key and SSL/TLS certificate.
Notes
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To use Security-Enhanced Linux (SELinux) and web servers, you must allow outbound TCP connections on port 2223, which is the port Client SDK 5 uses to communicate with the HSM.
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To create and activate a cluster and give an EC2 instance access to the cluster, complete the steps in Getting Started with AWS CloudHSM. The getting started offers step-by-step instruction for creating an active cluster with one HSM and an Amazon EC2 client instance. You can use this client instance as your web server.
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To avoid disabling client key durability, add more than one HSM to your cluster. For more information, see Adding an HSM to an AWS CloudHSM cluster.
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To connect to your client instance, you can use SSH or PuTTY. For more information, see Connecting to Your Linux Instance Using SSH or Connecting to Your Linux Instance from Windows Using PuTTY in the Amazon EC2 documentation.
Step 2: Generate the
private key and SSL/TLS certificate
To enable HTTPS, your web server application (NGINX or Apache) needs a private key and a corresponding SSL/TLS certificate. To use web server SSL/TLS offload with AWS CloudHSM, you must store the private key in an HSM in your AWS CloudHSM cluster. You will first generate a private key and use the key to create a certificate signing request (CSR). You then export a fake PEM private key from the HSM, which is a private key file in PEM format which contains a reference to the private key stored on the HSM (it's not the actual private key). Your web server uses the fake PEM private key file to identify the private key on the HSM during SSL/TLS offload.
Generate a private key and certificate
Generate a private key
This section shows you how to generate a keypair using the CloudHSM CLI. Once you have a key pair generated inside the HSM, you can export it as a fake PEM file and generate the corresponding certificate.
Install and configure the CloudHSM CLI
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Install and Configure the CloudHSM CLI.
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Use the following command to start the CloudHSM CLI.
$/opt/cloudhsm/bin/cloudhsm-cli interactive -
Run the following command to log in to the HSM. Replace
<user name>with the user name of your crypto-userCommand:login --username<user name>--role crypto-user
Generate a Private Key
Depending on your use case, you can either generate an RSA or an EC key pair. Do one of the following:
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To generate an RSA private key on an HSM
Use the key generate-asymmetric-pair rsa command to generate an RSA key pair. This example generates an RSA key pair with a modulus of 2048, a public exponent of 65537, public key label of
tls_rsa_pub, and private key label oftls_rsa_private.aws-cloudhsm >key generate-asymmetric-pair rsa \ --public-exponent 65537 \ --modulus-size-bits 2048 \ --public-label tls_rsa_pub \ --private-label tls_rsa_private --private-attributes sign=true{ "error_code": 0, "data": { "public_key": { "key-reference": "0x0000000000280cc8", "key-info": { "key-owners": [ { "username": "cu1", "key-coverage": "full" } ], "shared-users": [], "cluster-coverage": "full" }, "attributes": { "key-type": "rsa", "label": "tls_rsa_pub", "id": "", "check-value": "0x01fe6e", "class": "public-key", "encrypt": true, "decrypt": false, "token": true, "always-sensitive": false, "derive": false, "destroyable": true, "extractable": true, "local": true, "modifiable": true, "never-extractable": false, "private": true, "sensitive": false, "sign": false, "trusted": false, "unwrap": false, "verify": false, "wrap": false, "wrap-with-trusted": false, "key-length-bytes": 512, "public-exponent": "0x010001", "modulus": "0xb1d27e857a876f4e9fd5de748a763c539b359f937eb4b4260e30d1435485a732c878cdad9c72538e2215351b1d41358c9bf80b599c 73a80fdb457aa7b20cd61e486c326e2cfd5e124a7f6a996437437812b542e3caf85928aa866f0298580f7967ee6aa01440297d7308fdd9b76b70d1b67f12634d f6e6296d6c116d5744c6d60d14d3bf3cb978fe6b75ac67b7089bafd50d8687213b31abc7dc1bad422780d29c851d5102b56f932551eaf52a9591fd8c43d81ecc 133022653225bd129f8491101725e9ea33e1ded83fb57af35f847e532eb30cd7e726f23910d2671c6364092e834697ec3cef72cc23615a1ba7c5e100156ae0ac ac3160f0ca9725d38318b7", "modulus-size-bits": 2048 } }, "private_key": { "key-reference": "0x0000000000280cc7", "key-info": { "key-owners": [ { "username": "cu1", "key-coverage": "full" } ], "shared-users": [], "cluster-coverage": "full" }, "attributes": { "key-type": "rsa", "label": "tls_rsa_private", "id": "", "check-value": "0x01fe6e", "class": "private-key", "encrypt": false, "decrypt": true, "token": true, "always-sensitive": true, "derive": false, "destroyable": true, "extractable": true, "local": true, "modifiable": true, "never-extractable": false, "private": true, "sensitive": true, "sign": true, "trusted": false, "unwrap": false, "verify": false, "wrap": false, "wrap-with-trusted": false, "key-length-bytes": 1217, "public-exponent": "0x010001", "modulus": "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", "modulus-size-bits": 2048 } } } } -
To generate an EC private key on an HSM
Use the key generate-asymmetric-pair ec command to generate an EC key pair. This example generates an EC key pair with the
prime256v1curve (corresponding to theNID_X9_62_prime256v1curve), a public key label oftls_ec_pub, and a private key label oftls_ec_private.aws-cloudhsm >key generate-asymmetric-pair ec \ --curve prime256v1 \ --public-label tls_ec_pub \ --private-label tls_ec_private --private-attributes sign=true{ "error_code": 0, "data": { "public_key": { "key-reference": "0x000000000012000b", "key-info": { "key-owners": [ { "username": "cu1", "key-coverage": "full" } ], "shared-users": [], "cluster-coverage": "session" }, "attributes": { "key-type": "ec", "label": "tls_ec_pub", "id": "", "check-value": "0xd7c1a7", "class": "public-key", "encrypt": false, "decrypt": false, "token": false, "always-sensitive": false, "derive": false, "destroyable": true, "extractable": true, "local": true, "modifiable": true, "never-extractable": false, "private": true, "sensitive": false, "sign": false, "trusted": false, "unwrap": false, "verify": false, "wrap": false, "wrap-with-trusted": false, "key-length-bytes": 57, "ec-point": "0x047096513df542250a6b228fd9cb67fd0c903abc93488467681974d6f371083fce1d79da8ad1e9ede745fb9f38ac8622a1b3ebe9270556000c", "curve": "secp224r1" } }, "private_key": { "key-reference": "0x000000000012000c", "key-info": { "key-owners": [ { "username": "cu1", "key-coverage": "full" } ], "shared-users": [], "cluster-coverage": "session" }, "attributes": { "key-type": "ec", "label": "tls_ec_private", "id": "", "check-value": "0xd7c1a7", "class": "private-key", "encrypt": false, "decrypt": false, "token": false, "always-sensitive": true, "derive": false, "destroyable": true, "extractable": true, "local": true, "modifiable": true, "never-extractable": false, "private": true, "sensitive": true, "sign": true, "trusted": false, "unwrap": false, "verify": false, "wrap": false, "wrap-with-trusted": false, "key-length-bytes": 122, "ec-point": "0x047096513df542250a6b228fd9cb67fd0c903abc93488467681974d6f371083fce1d79da8ad1e9ede745fb9f38ac8622a1b3ebe9270556000c", "curve": "secp224r1" } } } }
Export a fake PEM private key file
Once you have a private key on the HSM, you must export a fake PEM private key file. This file does not contain the actual key data, but it allows the OpenSSL Dynamic Engine to identify the private key on the HSM. You can then you use the private key to create a certificate signing request (CSR) and sign the CSR to create the certificate.
Use the key generate-file command to export the private key in fake PEM format and save it to a file. Replace the following values with your own.
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<private_key_label>– Label of the private key you generated in the previous step. -
<web_server_fake_pem.key>– Name of the file that your fake PEM key will be written to.
aws-cloudhsm >key generate-file --encoding reference-pem --path<web_server_fake_pem.key>--filter attr.label=<private_key_label>{ "error_code": 0, "data": { "message": "Successfully generated key file" } }
Exit the CloudHSM CLI
Run the following command to stop the CloudHSM CLI.
aws-cloudhsm >quit
You should now have a new file on your system, located at the path specified by <web_server_fake_pem.key> in the preceding command.
This file is the fake PEM private key file.
Generate a self-signed certificate
Once you have generated a fake PEM private key, you can use this file to generate a certificate signing request (CSR) and certificate.
In a production environment, you typically use a certificate authority (CA) to create a certificate from a CSR. A CA is not necessary for a test environment. If you do use a CA, send the CSR file to them and use signed SSL/TLS certificate that they provide you in your web server for HTTPS.
As an alternative to using a CA, you can use the AWS CloudHSM OpenSSL Dynamic Engine to create a self-signed certificate. Self-signed certificates are not trusted by browsers and should not be used in production environments. They can be used in test environments.
Warning
Self-signed certificates should be used in a test environment only. For a production environment, use a more secure method such as a certificate authority to create a certificate.
Install and configure the OpenSSL Dynamic Engine
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Connect to your client instance.
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Install the OpenSSL Dynamic Engine for AWS CloudHSM Client SDK 5
Generate a certificate
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Obtain a copy of your fake PEM file generated in an earlier step.
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Create a CSR
Run the following command to use the AWS CloudHSM OpenSSL Dynamic Engine to create a certificate signing request (CSR). Replace
<web_server_fake_pem.key>with the name of the file that contains your fake PEM private key. Replace<web_server.csr>with the name of the file that contains your CSR.The
reqcommand is interactive. Respond to each field. The field information is copied into your SSL/TLS certificate.$openssl req -engine cloudhsm -new -key<web_server_fake_pem.key>-out<web_server.csr> -
Create a self-signed certificate
Run the following command to use the AWS CloudHSM OpenSSL Dynamic Engine to sign your CSR with your private key on your HSM. This creates a self-signed certificate. Replace the following values in the command with your own.
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<web_server.csr>– Name of the file that contains the CSR. -
<web_server_fake_pem.key>– Name of the file that contains the fake PEM private key. -
<web_server.crt>– Name of the file that will contain your web server certificate.
$openssl x509 -engine cloudhsm -req -days 365 -in<web_server.csr>-signkey<web_server_fake_pem.key>-out<web_server.crt> -
After you complete these steps, go to Step 3: Configure the web server.
Step 3: Configure the web server
Update your web server software's configuration to use the HTTPS certificate and corresponding fake PEM private key that you created in the previous step. Remember to backup your existing certificates and keys before you start. This will finish setting up your Linux web server software for SSL/TLS offload with AWS CloudHSM.
Complete the steps from one of the following sections.
Configure NGINX web server
Use this section to configure NGINX on supported platforms.
To update the web server configuration for NGINX
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Connect to your client instance.
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Run the following command to create the required directories for the web server certificate and the fake PEM private key.
$sudo mkdir -p /etc/pki/nginx/private -
Run the following command to copy your web server certificate to the required location. Replace
<web_server.crt>with the name of your web server certificate.$sudo cp<web_server.crt>/etc/pki/nginx/server.crt -
Run the following command to copy your fake PEM private key to the required location. Replace
<web_server_fake_pem.key>with the name of the file that contains your fake PEM private key.$sudo cp<web_server_example_pem.key>/etc/pki/nginx/private/server.key -
Run the following command to change the file ownership so that the user named nginx can read them.
$sudo chown nginx /etc/pki/nginx/server.crt /etc/pki/nginx/private/server.key -
Run the following command to back up the
/etc/nginx/nginx.conffile.$sudo cp /etc/nginx/nginx.conf /etc/nginx/nginx.conf.backup -
Update the NGINX configuration.
Note
Each cluster can support a maximum of 1000 NGINX worker processes across all NGINX web servers.
Use a text editor to edit the
/etc/nginx/nginx.conffile. This requires Linux root permissions. At the top of the file, add the following lines:ssl_engine cloudhsm; env CLOUDHSM_PIN;Then add the following to the TLS section of the file:
# Settings for a TLS enabled server. server { listen 443 ssl http2 default_server; listen [::]:443 ssl http2 default_server; server_name _; root /usr/share/nginx/html; ssl_certificate "/etc/pki/nginx/server.crt"; ssl_certificate_key "/etc/pki/nginx/private/server.key"; # It is *strongly* recommended to generate unique DH parameters # Generate them with: openssl dhparam -out /etc/pki/nginx/dhparams.pem 2048 #ssl_dhparam "/etc/pki/nginx/dhparams.pem"; ssl_session_cache shared:SSL:1m; ssl_session_timeout 10m; ssl_protocols TLSv1.2; ssl_ciphers "ECDHE-RSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA256:ECDHE-RSA-AES256-SHA384:DHE-RSA-AES128-SHA:DHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES256-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-ECDSA-AES256-SHA:ECDHE-ECDSA-AES128-SHA"; ssl_prefer_server_ciphers on; # Load configuration files for the default server block. include /etc/nginx/default.d/*.conf; location / { } error_page 404 /404.html; location = /40x.html { } error_page 500 502 503 504 /50x.html; location = /50x.html { } }Save the file.
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Back up the
systemdconfiguration file, and then set theEnvironmentFilepath.No action required.
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Check if the
/etc/sysconfig/nginxfile exists, and then do one of the following:-
If the file exists, back up the file by running the following command:
$sudo cp /etc/sysconfig/nginx /etc/sysconfig/nginx.backup -
If the file doesn't exist, open a text editor, and then create a file named
nginxin the/etc/sysconfig/folder.
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-
Configure the NGINX environment.
Note
Client SDK 5 introduces the
CLOUDHSM_PINenvironment variable for storing the credentials of the CU.Open the
/etc/sysconfig/nginxfile in a text editor. This requires Linux root permissions. Add the Cryptography User (CU) credentials:ssl_engine cloudhsm; env CLOUDHSM_PIN;Replace
<CU user name>and<password>with the CU credentials.Save the file.
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Start the NGINX web server.
Open the
/etc/sysconfig/nginxfile in a text editor. This requires Linux root permissions. Add the Cryptography User (CU) credentials:$sudo service nginx start -
(Optional) Configure your platform to start NGINX at start-up.
$sudo chkconfig nginx on
After you update your web server configuration, go to Step 4: Enable HTTPS traffic and verify the certificate.
Configure Apache web server
Use this section to configure Apache on supported platforms.
To update the web server configuration for Apache
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Connect to your Amazon EC2 client instance.
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Define default locations for certificates and private keys for your platform.
In the
/etc/httpd/conf.d/ssl.conffile, ensure these values exist:SSLCertificateFile/etc/pki/tls/certs/localhost.crtSSLCertificateKeyFile/etc/pki/tls/private/localhost.key -
Copy your web server certificate to the required location for your platform.
$sudo cp<web_server.crt>/etc/pki/tls/certs/localhost.crtReplace
<web_server.crt>with the name of your web server certificate. -
Copy your fake PEM private key to the required location for your platform.
$sudo cp<web_server_example_pem.key>/etc/pki/tls/private/localhost.keyReplace
<web_server_example_pem.key>with the name of the file that contains your fake PEM private key. -
Change ownership of these files if required by your platform.
$sudo chown apache /etc/pki/tls/certs/localhost.crt /etc/pki/tls/private/localhost.keyProvides read permission to the user named apache.
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Configure Apache directives for your platform.
Locate the SSL file for this platform:
/etc/httpd/conf.d/ssl.confThis file contains Apache directives which define how your server should run. Directives appear on the left, followed by a value. Use a text editor to edit this file. This requires Linux root permissions.
Update or enter the following directives with these values:
SSLCryptoDevicecloudhsmSSLCipherSuiteECDHE-RSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA256:ECDHE-RSA-AES256-SHA384:DHE-RSA-AES128-SHA:DHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES256-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-ECDSA-AES256-SHA:ECDHE-ECDSA-AES128-SHASave the file.
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Configure an environment-values file for your platform.
No action required. Environment values go in
/etc/sysconfig/httpd -
In the file that stores environment variables for your platform, set an environment variable that contains the credentials of the cryptographic user (CU):
Use a text editor to edit the
/etc/sysconfig/httpd.ssl_engine cloudhsm; env CLOUDHSM_PIN;Replace
<CU user name>and<password>with the CU credentials. -
Start the Apache web server.
$sudo systemctl daemon-reload$sudo service httpd start -
(Optional) Configure your platform to start Apache at start-up.
$sudo chkconfig httpd on
After you update your web server configuration, go to Step 4: Enable HTTPS traffic and verify the certificate.
Step 4: Enable HTTPS traffic
and verify the certificate
After you configure your web server for SSL/TLS offload with AWS CloudHSM, add your web server instance to a security group that allows inbound HTTPS traffic. This allows clients, such as web browsers, to establish an HTTPS connection with your web server. Then make an HTTPS connection to your web server and verify that it's using the certificate that you configured for SSL/TLS offload with AWS CloudHSM.
Enable inbound HTTPS connections
To connect to your web server from a client (such as a web browser), create a security group that allows inbound HTTPS connections. Specifically, it should allow inbound TCP connections on port 443. Assign this security group to your web server.
To create a security group for HTTPS and assign it to your web server
-
Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/
. -
Choose Security groups in the navigation pane.
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Choose Create security group.
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For Create Security Group, do the following:
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For Security group name, type a name for the security group that you are creating.
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(Optional) Type a description of the security group that you are creating.
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For VPC, choose the VPC that contains your web server Amazon EC2 instance.
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Select Add Rule.
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For Type, select HTTPS from the drop-down window.
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For Source, enter a source location.
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Choose Create security group.
-
-
In the navigation pane, choose Instances.
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Select the check box next to your web server instance.
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Select the Actions drop-down menu at the top of the page. Select Security and then Change Security Groups.
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For Associated security groups, select the search box and choose the security group that you created for HTTPS. Then choose Add Security Groups.
-
Select Save.
Verify that HTTPS uses the certificate that you configured
After you add the web server to a security group, you can verify that SSL/TLS offload is using your self-signed certificate.
You can do this with a web browser or with a tool such as OpenSSL s_client
To verify SSL/TLS offload with a web browser
-
Use a web browser to connect to your web server using the public DNS name or IP address of the server. Ensure that the URL in the address bar begins with https://. For example,
https://ec2-52-14-212-67.us-east-2.compute.amazonaws.com/.Tip
You can use a DNS service such as Amazon Route 53 to route your website's domain name (for example, https://www.example.com/) to your web server. For more information, see Routing Traffic to an Amazon EC2 Instance in the Amazon Route 53 Developer Guide or in the documentation for your DNS service.
-
Use your web browser to view the web server certificate. For more information, see the following:
-
For Mozilla Firefox, see View a Certificate
on the Mozilla Support website. -
For Google Chrome, see Understand Security Issues
on the Google Tools for Web Developers website.
Other web browsers might have similar features that you can use to view the web server certificate.
-
-
Ensure that the SSL/TLS certificate is the one that you configured your web server to use.
To verify SSL/TLS offload with OpenSSL s_client
-
Run the following OpenSSL command to connect to your web server using HTTPS. Replace
<server name>with the public DNS name or IP address of your web server.openssl s_client -connect<server name>:443Tip
You can use a DNS service such as Amazon Route 53 to route your website's domain name (for example, https://www.example.com/) to your web server. For more information, see Routing Traffic to an Amazon EC2 Instance in the Amazon Route 53 Developer Guide or in the documentation for your DNS service.
-
Ensure that the SSL/TLS certificate is the one that you configured your web server to use.
You now have a website that is secured with HTTPS. The private key for the web server is stored in an HSM in your AWS CloudHSM cluster.
To add a load balancer, see Add a load balancer with Elastic Load Balancing for AWS CloudHSM(optional).
