feat: Rough proof-of-concept for patch signing

library/Cargo.toml

@@ -14,6 +14,7 @@ crate-type = ["lib", "cdylib", "staticlib"]
 [dependencies]
 # Used for error handling for now.
 anyhow = { version = "1.0.69", features = ["backtrace"] }
+base64 = "0.22.0"
 # For inflating compressed patch files.
 bipatch = "1.0.0"
 # Used for exposing C API
@@ -41,6 +42,7 @@ reqwest = { version = "0.11", default-features = false, features = [
     "json",
     "rustls-tls",
 ] }
+ring = "0.17.8"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0.93"
 # For reading shorebird.yaml

library/src/c_api/mod.rs

@@ -480,6 +480,7 @@ mod test {
                         number: 1,
                         hash: hash.to_owned(),
                         download_url: "ignored".to_owned(),
+                        signature: None,
                     }),
                 })
             },
@@ -582,6 +583,7 @@ mod test {
                         number: 1,
                         hash: "ignored".to_owned(),
                         download_url: "ignored".to_owned(),
+                        signature: None,
                     }),
                 })
             },

library/src/cache/mod.rs

@@ -1,5 +1,6 @@
 mod disk_io;
 mod patch_manager;
+mod signing;
 pub mod updater_state;
 
 pub use updater_state::UpdaterState;