using-openssl.md

Creating dotnet-passbook certificates using OpenSSL

Using dotnet-passbook requires two certificates: the Apple Worldwide Developer Relations certificate (G1), available from Apple, and a second certificate which is specific to your application. Here's how to create them using OpenSSL if you can't (or don't want to) use IIS and the Windows certificate store.

Overview:

1. Download the Apple WWDR Certificate
2. Create a Pass Type ID using the Apple Developer portal
3. Create a certificate signing request (CSR) using OpenSSL
4. Use the Apple Developer portal to sign your CSR and create pass.cer which contains your passbook certificate.
5. Use OpenSSL to convert pass.cer from a binary-encoded DER format into a plain text PEM format.
6. Use OpenSSL to convert your PEM passbook certificate into PKCS12 (.pfx) format
7. Add the Apple WWDR Certificate and your PKCS12 certificate to your application.
8. Specify the paths to these two files when creating your passbook request.

Prerequisites

• An Apple Developer account / subscription.
• OpenSSL

Download the Apple WWDR certificate

You'll need the Worldwide Developer Relations certificate provided by Apple.

Download the certificate from https://developer.apple.com/certificationauthority/AppleWWDRCA.cer

Save this certificate to your project folder as AppleWWDRCA.cer

⚠️ The page at https://www.apple.com/certificateauthority/ links to multiple versions (generations?) of the Worldwide Developer Relations certificate (G1, G2, G3, G5 and G6).

Only G1 will generate valid Apple Wallet passes.

The others will work, you'll get a signed that works OK with Passbook, but when you try to save the generated .pkpass to your Apple Wallet you'll get an error that says "Sorry, your Pass cannot be installed to Passbook at this time."

Create a Pass Type ID

Sign in to your Apple Developer account and go to Certificates, Identifiers & Profiles

Click Identifiers. In the App IDs dropdown at top right, select Pass Type IDs:

If you have any existing Pass Type IDs, you'll see them listed here. To create a new one, click the blue plus icon next to Identifiers:

Provide a description (friendly and human readable), and an identifer (pass.com.company.appname or something similar):

Generate a Certificate Signing Request using openSSL

The OpenSSL command to to this is:

openssl req -new -newkey rsa:2048 -out passbook.csr -keyout passbook.key

• openssl req runs openssl and specifies we're working with certificate signing requests (CSRs)
• -new creates a new CSR
• -newkey rsa:2048 specifies that our CSR should be signed using a new 2048-bit RSA key
• -out passbook.csr specifies the output filename for our certificate signing request
• -keyout passbook.key specifies the output filename for our signing key

OpenSSL will prompt you for a bunch of details. First, it'll ask you for a passphrase. Remember what this is - you'll need it every time you do anything with your signing key.

Generating a RSA private key
............+++++
.................................................+++++
writing new private key to 'passbook.key'
Enter PEM pass phrase:
Verifying - Enter PEM pass phrase:

Next it'll prompt you for a bunch of details to include in the CSR:

-----
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter '.', the field will be left blank.
-----
Country Name (2 letter code) [XX]:GB
State or Province Name (full name) []:London
Locality Name (eg, city) [Default City]:London
Organization Name (eg, company) [Default Company Ltd]:Ursatile Ltd
Organizational Unit Name (eg, section) []:iOS Development
Common Name (eg, your name or your server hostname) []:passbook.ursatile.com
Email Address []:[email protected]

Please enter the following 'extra' attributes
to be sent with your certificate request
A challenge password []:
An optional company name []:

That's it. You should now have two new files:

• passbook.key contains your private signing key
• passbook.csr contains your certificate signing request

ℹ️ You can also specify all these parameters via the -subj argument to OpenSSL:

openssl req -new -newkey rsa:2048 -out passbook.csr -keyout passbook.key \
  -subj "/C=GB/ST=London/L=London/O=Ursatile Ltd/OU=iOS Development/CN=passbook.ursatile.com"

Use the Apple Developer portal to sign your CSR

Sign in to the Apple Developer portal, go to Certificates, Add, scroll down to Services, select Pass Type ID Certificate:

Click Continue. Provide a Pass certificate name, and choose the Pass Type ID you selected in step 2:

Upload the passbook.csr file you created earlier using openSSL:

Your certificate has been created. When you click Download, you'll get a pass.cer file. Save this into your project folder.

Convert your certificate to a format you can use with Passbook

First, you'll need to convert pass.cer from a DER binary-encoded format into a PEM (text) certificate format:

openssl x509 -in pass.cer -inform der -out passbook.pem

Next convert the PEM file into a PKCS12 file you can use in your .NET application:

openssl pkcs12 -export -out passbook.pfx -inkey passbook.key -in passbook.pem

You'll need to enter the pass phrase for your private signing key, and then specify an Export Password (twice):

Enter pass phrase for passbook.key:
Enter Export Password: <your_export_password>
Verifying - Enter Export Password: <your_export_password>

Using your certificates to sign Apple Wallet passes with Dotnet Passbook

You'll need to include this export password when you create your passbook request in your .NET application:

var request = new PassGeneratorRequest();
request.AppleWWDRCACertificate = File.ReadAllBytes("AppleWWDRCA.cer");
request.Certificate = File.ReadAllBytes("passbook.pfx");
request.CertificatePassword = "<your_export_password>";