Sign extensions manually with OpenSSL

• How-to guide
• 4-min read
• Published Apr 21, 2021

Use OpenSSL

To sign your extension manually, use OpenSSL. For Windows, you need to download and install an OpenSSL binary of your choice. We tested the procedure with OpenSSL 1.1.1k.

Create the root key and certificate

Add your root certificate to the Dynatrace credential vault

Create a developer certificate

Sign your extension

Verify signature

Create extension package

Create the root key and certificate

Your company should issue developer certificates from a company-wide root certificate. When developers sign their extensions with their own developer certificates, Dynatrace will be able to verify the extension authenticity against your root certificate stored in the Dynatrace credential vault and on the hosts where extensions are executed.

Run the following commands to generate your organization's root certificate. Do not set the password. Password-protected certificates are not supported by Dynatrace.

openssl genrsa -out root.key 2048
openssl req -new -key root.key -out root.csr

When generating the root certificate, you need to explicitly define the certificate extension by pointing the -extfile property to the ca.txt file. The file should contain the following data:

basicConstraints=critical, CA:true, pathlen:0
subjectKeyIdentifier    = hash
authorityKeyIdentifier  = keyid:always
keyUsage                = keyCertSign

openssl x509 -req -days 10000 -in root.csr -signkey root.key -out root.pem -extfile ca.txt

This generates your root.pem root certificate.

Note that you can also use an existing root certificate to generate developer certificates. Dynatrace accepts only PFX, P12, and PEM formats, so you may need to convert the existing certificate to one of the allowed formats. Refer to the OpenSSL documentation for conversion instructions.

Add your root certificate to the Dynatrace credential vault

Create a developer certificate

To create your developer certificate, you need to create a developer certificate signing request and then issue the certificate.

Create a developer certificate signing request

Run the following commands to generate the certificate signing request (CSR) to the root CA:

openssl genrsa -out developer.key 2048

openssl req -new -key developer.key -out developer.csr

When filling in the fields for the Distinguished Name (DN), make sure that at least one of the fields is different than the DN you defined for the root certificate.

The result is the developer.csr CSR that you'll use to issue the developer certificate from the root certificate.

Issue a developer certificate

Run the following commands to generate the developer certificate:

openssl req -new -key developer.key -out developer.csr

When generating the developer certificate, you need to explicitly define the certificate extension by pointing the -extfile property to the developer.txt file. The file should contain the following data:

subjectKeyIdentifier    = hash
authorityKeyIdentifier  = keyid:always
keyUsage                = digitalSignature

openssl x509 -req -days 10000 -in developer.csr -CA root.pem -CAkey root.key -CAcreateserial -out developer.pem -extfile developer.txt

The result is the developer.pem certificate file that you'll use for signing your extensions.

Sign your extension

With the developer certificate in place, use the following command to sign your extension. Make sure that your extension.zip file is in the directory from which you run the command.

openssl cms -sign -signer developer.pem -inkey developer.key -binary -in extension.zip -outform PEM -out extension.zip.sig

The result is an extension.zip.sig signature file.

Verify signature

Use the following command to verify the extension.zip.sig signature file against the root.pem root certificate:

openssl cms -verify -CAfile root.pem -in extension.zip.sig -binary -content extension.zip -inform PEM -out /dev/null

openssl cms -verify -CAfile root.pem -in extension.zip.sig -binary -content extension.zip -inform PEM -out NUL

The output should contain the phrase Verification successful.

Create extension package

For the final step, create an extension package containing only the extension.zip archive and the extension.zip.sig signature file.

bundle.zip
|    extension.zip
|    extension.zip.sig

You can now upload the extension package to your Dynatrace environment. For more information, see Manage Extensions.