docs(guides): add more detail to code-signing (#25794)

Co-authored-by: Emily Rohrbough <emilyrohrbough@users.noreply.github.com>

Author: flotwig

guides/code-signing.md

@@ -4,20 +4,37 @@ Code signing is done for the Windows and Mac distributions of Cypress when they
 
 `electron-builder` handles code signing during the `create-build-artifacts` jobs. This guide assumes that the reader is already familiar with [`electron-builder`'s Code Signing documentation](https://www.electron.build/code-signing).
 
-## Installing a new Mac code signing key
+## Rotating the Mac code signing key
 
-Follow the directions supplied by `electron-builder`: https://www.electron.build/code-signing#travis-appveyor-and-other-ci-servers
+1. On a Mac, log in to Xcode using Cypress's Apple developer program identity.
+2. Follow Apple's [Create, export, and delete signing certificates](https://help.apple.com/xcode/mac/current/#/dev154b28f09) instructions:
+    1. Follow "View signing certificates".
+    2. Follow "Create a signing certificate", and choose the type of "Developer ID Application" when prompted.
+    3. Follow "Export a signing certificate". Set a strong passphrase when prompted, which will later become `CSC_KEY_PASSWORD`.
+3. Upload the exported, encrypted `.p12` file to the [Code Signing folder][code-signing-folder] in Google Drive and obtain a public [direct download link][direct-download].
+4. Within the `test-runner:sign-mac-binary` CircleCI context, set `CSC_LINK` to that direct download URL and set `CSC_KEY_PASSWORD` to the passphrase used to encrypt the `p12` file.
 
-Set the environment variables `CSC_LINK` and `CSC_KEY_PASSWORD` in the `test-runner:sign-mac-binary` CircleCI context.
+## Rotating the Windows code signing key
 
-## Installing a new Windows code signing key
-
-1. Obtain the private key and full certificate chain in ASCII-armored PEM format and store each in a file (`-----BEGIN PRIVATE KEY-----`, `-----BEGIN CERTIFICATE-----`)
-2. Using `openssl`, convert the plaintext PEM public and private key to binary PKCS#12/PFX format and encrypt it with a real strong password.
+1. Generate a certificate signing request (CSR) file using `openssl`. For example:
+    ```shell
+    # generate a new private key
+    openssl genrsa -out win-code-signing.key 4096
+    # create a CSR using the private key
+    openssl req -new -key win-code-signing.key -out win-code-signing.csr
+    ```
+2. Obtain a certificate by submitting the CSR to SSL.com using the Cypress SSL.com account.
+    * If renewing, follow the [renewal instructions](https://www.ssl.com/how-to/renewing-ev-ov-and-iv-certificates/).
+    * If rotating, contact SSL.com's support to request certificate re-issuance.
+3. Obtain the full certificate chain from SSL.com's dashboard in ASCII-armored PEM format and save it as `win-code-signing.crt`. (`-----BEGIN PRIVATE KEY-----`, `-----BEGIN CERTIFICATE-----`)
+4. Using `openssl`, convert the plaintext PEM public and private key to binary PKCS#12/PFX format and encrypt it with a strong passphrase, which will later become `CSC_KEY_PASSWORD`.
     ```shell
-    ➜ openssl pkcs12 -export -inkey key.pem -in cert.pem -out encrypted.pfx
+    ➜ openssl pkcs12 -export -inkey win-code-signing.key -in win-code-signing.crt -out encrypted-win-code-signing.pfx
     Enter Export Password: <password>
     Verifying - Enter Export Password: <password>
     ```
-3. Upload the `encrypted.pfx` file to the Cypress App Google Drive and obtain a [direct download link](http://www.syncwithtech.org/p/direct-download-link-generator.html).
-4. Within the `test-runner:sign-windows-binary` CircleCI context, set `CSC_LINK` to that URL and `CSC_KEY_PASSWORD` to the password.
+5. Upload the `encrypted-win-code-signing.pfx` file to the [Code Signing folder][code-signing-folder] in Google Drive and obtain a public [direct download link][direct-download].
+6. Within the `test-runner:sign-windows-binary` CircleCI context, set `CSC_LINK` to that direct download URL and set `CSC_KEY_PASSWORD` to the passphrase used to encrypt the `pfx` file.
+
+[direct-download]: https://www.syncwithtech.org/p/direct-download-link-generator.html
+[code-signing-folder]: https://drive.google.com/drive/u/1/folders/1CsuoXRDmXvd3ImvFI-sChniAMJBASUW