Encode key in base64 instead of hexa

Cargo.lock

@@ -1973,6 +1973,7 @@ checksum = "a3e378b66a060d48947b590737b30a1be76706c8dd7b8ba0f2fe3989c68a853f"
 name = "meilisearch-auth"
 version = "0.27.1"
 dependencies = [
+ "base64",
  "enum-iterator",
  "meilisearch-error",
  "milli",

meilisearch-auth/Cargo.toml

@@ -11,6 +11,7 @@ rand = "0.8.4"
 serde = { version = "1.0.136", features = ["derive"] }
 serde_json = { version = "1.0.79", features = ["preserve_order"] }
 sha2 = "0.10.2"
+base64 = "0.13.0"
 thiserror = "1.0.30"
 time = { version = "0.3.7", features = ["serde-well-known", "formatting", "parsing", "macros"] }
 uuid = { version = "0.8.2", features = ["serde", "v4"] }

meilisearch-auth/src/store.rs

@@ -238,7 +238,7 @@ impl<'a> milli::heed::BytesEncode<'a> for KeyIdActionCodec {
 pub fn generate_key(uid: &[u8], master_key: &[u8]) -> String {
     let key = [uid, master_key].concat();
     let sha = Sha256::digest(&key);
-    format!("{:x}", sha)
+    base64::encode_config(sha, base64::URL_SAFE_NO_PAD)
 }
 
 /// Divides one slice into two at an index, returns `None` if mid is out of bounds.