Added support for multiple providers and wrote additional regression tests. Also fixed a bug with local synchronization with remote Git repositories when the CLI was just installed but the remote repo already exists with stuff in it.

tests/prop_crypto.rs

@@ -0,0 +1,32 @@
+use base64::Engine;
+use gman::{decrypt_string, encrypt_string};
+use proptest::prelude::*;
+use secrecy::SecretString;
+
+proptest! {
+    #[test]
+    fn prop_encrypt_decrypt_roundtrip(password in ".{0,64}", msg in ".{0,2048}") {
+        let pw = SecretString::new(password.into());
+        let env = encrypt_string(pw.clone(), &msg).unwrap();
+        let out = decrypt_string(pw, &env).unwrap();
+
+        prop_assert_eq!(out, msg);
+    }
+
+    #[test]
+    fn prop_tamper_ciphertext_detected(password in ".{0,32}", msg in ".{1,256}") {
+        let pw = SecretString::new(password.into());
+        let env = encrypt_string(pw.clone(), &msg).unwrap();
+        // Flip a bit in the ct payload segment
+        let mut parts: Vec<&str> = env.split(';').collect();
+        let ct_b64 = parts[6].strip_prefix("ct=").unwrap();
+        let mut ct = base64::engine::general_purpose::STANDARD.decode(ct_b64).unwrap();
+        ct[0] ^= 0x1;
+        let new_ct_b64 = base64::engine::general_purpose::STANDARD.encode(&ct);
+        let new_ct = format!("ct={}", new_ct_b64);
+        parts[6] = Box::leak(new_ct.into_boxed_str());
+        let tampered = parts.join(";");
+
+        prop_assert!(decrypt_string(pw, &tampered).is_err());
+    }
+}