Custom format for url-safe unpadded base64

Co-authored-by: Kévin Commaille <76261501+zecakeh@users.noreply.github.com>

data/api/client-server/definitions/encrypted_file.yaml

@@ -45,6 +45,7 @@ properties:
         example: A256CTR
       k:
         type: string
+        format: mx-urlsafe-unpadded-base64
         description: The key, encoded as [URL-safe unpadded Base64](/appendices/#url-safe-unpadded-base64).
         example: "aWF6-32KGYaC3A_FEUCk1Bt0JA37zP0wrStgmdCaW-0"
       ext:
@@ -59,6 +60,7 @@ properties:
       - ext
   iv:
     type: string
+    format: mx-unpadded-base64
     description: The 128-bit unique counter block used by AES-CTR, encoded as [unpadded Base64](/appendices/#unpadded-base64).
     example: "w+sE15fzSc0AAAAAAAAAAA"
   hashes:
@@ -69,6 +71,7 @@ properties:
     properties:
       sha256:
         type: string
+        format: mx-unpadded-base64
         description: The hash of the ciphertext. encoded as [unpadded Base64](/appendices/#unpadded-base64).
         example: "fdSLu/YkRx3Wyh3KQabP3rd6+SFiKg5lsJZQHtkSAYA"
     required: ['sha256']

data/string-formats.yaml

@@ -71,6 +71,11 @@ mx-unpadded-base64:
   url: appendices#unpadded-base64
   # no regex
 
+mx-urlsafe-unpadded-base64:
+  title: URL-safe unpadded Base64
+  url: appendices/#url-safe-unpadded-base64
+  # no regex
+
 uri:
   title: URI
   url: https://datatracker.ietf.org/doc/html/rfc3986