src-tauri/Cargo.toml

@@ -66,3 +66,13 @@ hmac = "0.12"
 ed25519-dalek = { version = "2", features = ["pkcs8", "rand_core"] }
 # HTTP mock server for balance_commands fetch_price tests (Issue #155).
 mockito = "1.6"
+
+[features]
+# Dev-only escape hatch: when enabled, the SR_DEV_EDITION env var forces the
+# resolved edition (free|base|premium) so the three license tiers can be tested
+# without real license files. MUST stay out of `default` and of any release
+# feature set — gating this on debug_assertions instead would let a custom
+# release build honor the env var and become a Premium backdoor (CWE-489).
+# Usage: cargo test --features dev-override, or `tauri dev` with
+# `-- --features dev-override`.
+dev-override = []

src-tauri/src/commands/entitlements.rs

@@ -1,8 +1,15 @@
 // Centralized feature → tier mapping for license entitlements.
 //
-// This module is the single source of truth for which features are gated by which tier.
-// To change what is gated where, modify FEATURE_TIERS only — never sprinkle edition checks
-// throughout the codebase.
+// This module is the single source of truth for which features are gated by which tier
+// on the Rust side. To change what is gated where, modify FEATURE_TIERS only — never
+// sprinkle edition checks throughout the codebase.
+//
+// Since the tier-gating work (#297-#301), UI-level gates (budget, adjustments,
+// reports-advanced, multi-profile, balance) live in the TS matrix
+// `src/shared/entitlements.ts` (soft-paywall, UI-only enforcement). This table
+// only keeps the features actually checked through `check_entitlement` — the
+// JWT `features[]` array is a namespace shared with that TS layer, so keys are
+// kebab-case on both sides.
 
 /// Editions, ordered from least to most privileged.
 pub const EDITION_FREE: &str = "free";
@@ -10,17 +17,11 @@ pub const EDITION_BASE: &str = "base";
 pub const EDITION_PREMIUM: &str = "premium";
 
 /// Maps feature name → list of editions allowed to use it.
-/// A feature absent from this list is denied for all editions.
-const FEATURE_TIERS: &[(&str, &[&str])] = &[
-    // auto-update is temporarily open to FREE until the license server (issue #49)
-    // is live. Re-gate to [BASE, PREMIUM] once paid activation works end-to-end.
-    ("auto-update", &[EDITION_FREE, EDITION_BASE, EDITION_PREMIUM]),
-    ("web-sync", &[EDITION_PREMIUM]),
-    ("cloud-backup", &[EDITION_PREMIUM]),
-    ("advanced-reports", &[EDITION_PREMIUM]),
-];
+/// A feature absent from this list is denied for all editions, unless the
+/// license carries it in its signed `features[]` override (see [`is_entitled`]).
+const FEATURE_TIERS: &[(&str, &[&str])] = &[("auto-update", &[EDITION_BASE, EDITION_PREMIUM])];
 
-/// Pure check: does `edition` grant access to `feature`?
+/// Pure check: does `edition` grant access to `feature` via the static matrix?
 pub fn is_feature_allowed(feature: &str, edition: &str) -> bool {
     FEATURE_TIERS
         .iter()
@@ -29,10 +30,28 @@ pub fn is_feature_allowed(feature: &str, edition: &str) -> bool {
         .unwrap_or(false)
 }
 
+/// Static matrix check OR signed per-license `features[]` override.
+///
+/// Fail-closed in Free (CWE-863): a `license.key` copied onto another machine
+/// resolves to "free" through the machine-binding path, which already drops the
+/// signed features (see `license_commands::current_entitlements`). As defense
+/// in depth we also refuse the override here whenever the edition is free, so
+/// signed features can never rescue a downgraded license.
+pub fn is_entitled(feature: &str, edition: &str, features: &[String]) -> bool {
+    if edition == EDITION_FREE {
+        return is_feature_allowed(feature, edition);
+    }
+    is_feature_allowed(feature, edition) || features.iter().any(|f| f == feature)
+}
+
+/// Tauri command: is `feature` available right now? Edition AND signed
+/// per-license feature overrides are resolved through the same machine-binding
+/// path (`license_commands::current_entitlements`), then combined by
+/// [`is_entitled`].
 #[tauri::command]
 pub fn check_entitlement(app: tauri::AppHandle, feature: String) -> Result<bool, String> {
-    let edition = crate::commands::license_commands::current_edition(&app);
-    Ok(is_feature_allowed(&feature, &edition))
+    let (edition, features) = crate::commands::license_commands::current_entitlements(&app);
+    Ok(is_entitled(&feature, &edition, &features))
 }
 
 #[cfg(test)]
@@ -40,9 +59,8 @@ mod tests {
     use super::*;
 
     #[test]
-    fn free_allows_auto_update_temporarily() {
-        // Temporary: auto-update is open to FREE until the license server is live.
-        assert!(is_feature_allowed("auto-update", EDITION_FREE));
+    fn free_denied_auto_update() {
+        assert!(!is_feature_allowed("auto-update", EDITION_FREE));
     }
 
     #[test]
@@ -51,20 +69,43 @@ mod tests {
     }
 
     #[test]
-    fn premium_unlocks_everything() {
+    fn premium_unlocks_auto_update() {
         assert!(is_feature_allowed("auto-update", EDITION_PREMIUM));
-        assert!(is_feature_allowed("web-sync", EDITION_PREMIUM));
-        assert!(is_feature_allowed("cloud-backup", EDITION_PREMIUM));
-    }
-
-    #[test]
-    fn base_does_not_unlock_premium_features() {
-        assert!(!is_feature_allowed("web-sync", EDITION_BASE));
-        assert!(!is_feature_allowed("cloud-backup", EDITION_BASE));
     }
 
     #[test]
     fn unknown_feature_denied() {
         assert!(!is_feature_allowed("nonexistent", EDITION_PREMIUM));
     }
+
+    #[test]
+    fn matrix_grants_without_override() {
+        assert!(is_entitled("auto-update", EDITION_BASE, &[]));
+        assert!(is_entitled("auto-update", EDITION_PREMIUM, &[]));
+    }
+
+    #[test]
+    fn unlisted_feature_denied_without_override() {
+        // "balance" lives in the TS matrix only — absent from FEATURE_TIERS,
+        // so the static path denies it for every edition.
+        assert!(!is_entitled("balance", EDITION_BASE, &[]));
+        assert!(!is_entitled("balance", EDITION_PREMIUM, &[]));
+    }
+
+    #[test]
+    fn override_grants_unlisted_feature_for_paid_editions() {
+        let features = vec!["balance".to_string()];
+        assert!(is_entitled("balance", EDITION_BASE, &features));
+        assert!(is_entitled("balance", EDITION_PREMIUM, &features));
+    }
+
+    #[test]
+    fn override_ignored_in_free() {
+        // CWE-863: signed features[] must never rescue a license downgraded to
+        // free (copied key / machine mismatch) — not even for a feature that a
+        // paid edition would get from the static matrix.
+        let features = vec!["balance".to_string(), "auto-update".to_string()];
+        assert!(!is_entitled("balance", EDITION_FREE, &features));
+        assert!(!is_entitled("auto-update", EDITION_FREE, &features));
+    }
 }

src-tauri/src/commands/license_commands.rs

@@ -221,51 +221,117 @@ pub fn get_edition(app: tauri::AppHandle) -> Result<String, String> {
     Ok(current_edition(&app))
 }
 
-/// Internal helper used by `entitlements::check_entitlement`. Never returns an error — any
-/// failure resolves to "free" so feature gates fail closed.
-///
-/// Priority: Premium (via Compte Maximus with active subscription) > Base (offline license) > Free.
-pub(crate) fn current_edition(app: &tauri::AppHandle) -> String {
-    // Check Compte Maximus subscription first — Premium overrides Base
-    if let Some(edition) = check_account_edition(app) {
-        if edition == EDITION_PREMIUM {
-            return edition;
-        }
-    }
-
-    let Ok(path) = license_path(app) else {
-        return EDITION_FREE.to_string();
-    };
-    if !path.exists() {
-        return EDITION_FREE.to_string();
-    }
-    let Ok(key) = fs::read_to_string(&path) else {
-        return EDITION_FREE.to_string();
-    };
-    let Ok(decoding_key) = embedded_decoding_key() else {
-        return EDITION_FREE.to_string();
-    };
-    let Ok(info) = validate_with_key(&key, &decoding_key) else {
-        return EDITION_FREE.to_string();
-    };
-
-    // If an activation token exists, it must match the local machine. A missing token is
-    // accepted (graceful pre-activation).
-    if let Ok(activation_path) = activation_path(app) {
-        if activation_path.exists() {
-            let Ok(token) = fs::read_to_string(&activation_path) else {
-                return EDITION_FREE.to_string();
-            };
-            let Ok(local_id) = machine_id_internal() else {
-                return EDITION_FREE.to_string();
-            };
-            if validate_activation_with_key(&token, &local_id, &decoding_key).is_err() {
-                return EDITION_FREE.to_string();
+/// Dev-only edition override, compiled in ONLY under the `dev-override` Cargo
+/// feature (off by default and absent from any release feature set). Gating on
+/// `debug_assertions` instead would be CWE-489: a custom release build could
+/// flip it on and the env var would become a Premium backdoor. When compiled
+/// in, `SR_DEV_EDITION` forces the resolved edition (free|base|premium) so the
+/// three tiers can be tested without real licenses; unrecognized values are
+/// ignored and resolution falls through to the normal path.
+fn dev_override_edition() -> Option<String> {
+    #[cfg(feature = "dev-override")]
+    {
+        if let Ok(edition) = std::env::var("SR_DEV_EDITION") {
+            if edition == EDITION_FREE || edition == EDITION_BASE || edition == EDITION_PREMIUM {
+                return Some(edition);
             }
         }
     }
+    None
+}
 
-    info.edition
+/// Pure resolution of `(edition, signed features)` from license material.
+///
+/// Single choke point for the machine-binding rule: every downgrade path
+/// returns `("free", [])`, so the signed `features[]` of a copied license can
+/// never be honored once the edition is downgraded (CWE-863). Separated from
+/// the fs/AppHandle plumbing so tests can exercise it with in-memory keys.
+fn resolve_license_entitlements(
+    license_key: &str,
+    activation_token: Option<&str>,
+    local_machine_id: &str,
+    decoding_key: &DecodingKey,
+) -> (String, Vec<String>) {
+    let Ok(info) = validate_with_key(license_key, decoding_key) else {
+        return (EDITION_FREE.to_string(), Vec::new());
+    };
+    // If an activation token exists, it must match the local machine. A missing
+    // token is accepted (graceful pre-activation state).
+    if let Some(token) = activation_token {
+        if validate_activation_with_key(token, local_machine_id, decoding_key).is_err() {
+            return (EDITION_FREE.to_string(), Vec::new());
+        }
+    }
+    (info.edition, info.features)
+}
+
+/// Internal helper used by `entitlements::check_entitlement`. Resolves the
+/// effective edition AND the signed per-license feature overrides through the
+/// SAME machine-binding path. Never returns an error — any failure resolves to
+/// `("free", [])` so feature gates fail closed, features included (CWE-863: a
+/// copied `license.key` must not keep its signed `features[]` once downgraded).
+///
+/// Priority: dev override (dev-override builds only) > Premium (via Compte
+/// Maximus with active subscription) > Base (offline license) > Free.
+pub(crate) fn current_entitlements(app: &tauri::AppHandle) -> (String, Vec<String>) {
+    // Dev-only tier testing — compiled out of normal builds (see the helper).
+    if let Some(edition) = dev_override_edition() {
+        return (edition, Vec::new());
+    }
+
+    // Check Compte Maximus subscription first — Premium overrides Base. This
+    // path never reads the license JWT, so it carries no signed features.
+    if let Some(edition) = check_account_edition(app) {
+        if edition == EDITION_PREMIUM {
+            return (edition, Vec::new());
+        }
+    }
+
+    let free = || (EDITION_FREE.to_string(), Vec::new());
+
+    let Ok(path) = license_path(app) else {
+        return free();
+    };
+    if !path.exists() {
+        return free();
+    }
+    let Ok(key) = fs::read_to_string(&path) else {
+        return free();
+    };
+    let Ok(decoding_key) = embedded_decoding_key() else {
+        return free();
+    };
+
+    // Read the activation token when present. An unreadable token or machine
+    // id resolves to free, matching the strict posture of `current_edition`
+    // before this refactor.
+    let mut activation_token: Option<String> = None;
+    let mut local_machine_id = String::new();
+    if let Ok(act_path) = activation_path(app) {
+        if act_path.exists() {
+            let Ok(token) = fs::read_to_string(&act_path) else {
+                return free();
+            };
+            let Ok(local_id) = machine_id_internal() else {
+                return free();
+            };
+            activation_token = Some(token);
+            local_machine_id = local_id;
+        }
+    }
+
+    resolve_license_entitlements(
+        &key,
+        activation_token.as_deref(),
+        &local_machine_id,
+        &decoding_key,
+    )
+}
+
+/// Edition-only view of [`current_entitlements`], used by `get_edition` and any
+/// caller that does not need the feature overrides.
+pub(crate) fn current_edition(app: &tauri::AppHandle) -> String {
+    current_entitlements(app).0
 }
 
 /// Read the HMAC-verified account cache to check for an active Premium
@@ -677,4 +743,118 @@ mod tests {
         // Sanity check that the production PEM constant is well-formed.
         assert!(embedded_decoding_key().is_ok());
     }
+
+    // === Entitlements resolution (edition + signed features, machine binding) =================
+
+    fn base_license_with_features(enc: &EncodingKey, features: Vec<String>) -> String {
+        let claims = LicenseClaims {
+            sub: "user@example.com".to_string(),
+            iss: "lacompagniemaximus.com".to_string(),
+            iat: now(),
+            exp: now() + 86400,
+            edition: EDITION_BASE.to_string(),
+            features,
+            machine_limit: 3,
+        };
+        let jwt = make_token(enc, &claims);
+        format!("{}{}", KEY_PREFIX_BASE, jwt)
+    }
+
+    fn activation_for(enc: &EncodingKey, machine_id: &str) -> String {
+        let claims = ActivationClaims {
+            sub: "license-id".to_string(),
+            iat: now(),
+            exp: now() + 86400,
+            machine_id: machine_id.to_string(),
+        };
+        make_token(enc, &claims)
+    }
+
+    #[test]
+    fn machine_match_keeps_edition_and_features() {
+        let (enc, dec) = default_keys();
+        let key = base_license_with_features(&enc, vec!["balance".to_string()]);
+        let token = activation_for(&enc, "machine-A");
+        let (edition, features) =
+            resolve_license_entitlements(&key, Some(&token), "machine-A", &dec);
+        assert_eq!(edition, EDITION_BASE);
+        assert_eq!(features, vec!["balance".to_string()]);
+    }
+
+    #[test]
+    fn machine_mismatch_downgrades_to_free_and_drops_features() {
+        // CWE-863: a copied license.key + activation.token still carries its
+        // signed features[] — they must vanish together with the downgrade.
+        let (enc, dec) = default_keys();
+        let key = base_license_with_features(&enc, vec!["balance".to_string()]);
+        let token = activation_for(&enc, "machine-A");
+        let (edition, features) =
+            resolve_license_entitlements(&key, Some(&token), "machine-B", &dec);
+        assert_eq!(edition, EDITION_FREE);
+        assert!(
+            features.is_empty(),
+            "signed features must not survive the machine-binding downgrade"
+        );
+    }
+
+    #[test]
+    fn missing_activation_token_keeps_edition_and_features() {
+        // Graceful pre-activation state: no token yet, the license still counts.
+        let (enc, dec) = default_keys();
+        let key = base_license_with_features(&enc, vec!["balance".to_string()]);
+        let (edition, features) = resolve_license_entitlements(&key, None, "machine-A", &dec);
+        assert_eq!(edition, EDITION_BASE);
+        assert_eq!(features, vec!["balance".to_string()]);
+    }
+
+    #[test]
+    fn invalid_license_resolves_free_without_features() {
+        let (_enc, dec) = default_keys();
+        let (edition, features) =
+            resolve_license_entitlements("SR-BASE-not.a.jwt", None, "machine-A", &dec);
+        assert_eq!(edition, EDITION_FREE);
+        assert!(features.is_empty());
+    }
+
+    // === Dev override =========================================================================
+
+    /// The dev override must be dead code in normal builds: even with
+    /// SR_DEV_EDITION set, nothing reads it when the `dev-override` Cargo
+    /// feature is off (CWE-489 — a release binary must never honor the env
+    /// var). Env-var note: under this feature-off build NO code path reads
+    /// SR_DEV_EDITION, so setting it here cannot race with parallel tests.
+    #[cfg(not(feature = "dev-override"))]
+    #[test]
+    fn sr_dev_edition_has_no_effect_when_feature_off() {
+        std::env::set_var("SR_DEV_EDITION", "premium");
+        assert_eq!(dev_override_edition(), None);
+        std::env::remove_var("SR_DEV_EDITION");
+    }
+
+    // Companion coverage for `cargo test --features dev-override` (not part of
+    // the normal CI run). SR_DEV_EDITION is process-global and cargo test runs
+    // tests on parallel threads, so every env manipulation serializes on a lock.
+    #[cfg(feature = "dev-override")]
+    mod dev_override_on {
+        use super::super::*;
+        use std::sync::Mutex;
+
+        static ENV_LOCK: Mutex<()> = Mutex::new(());
+
+        #[test]
+        fn sr_dev_edition_forces_edition() {
+            let _guard = ENV_LOCK.lock().unwrap();
+            std::env::set_var("SR_DEV_EDITION", "premium");
+            assert_eq!(dev_override_edition(), Some("premium".to_string()));
+            std::env::remove_var("SR_DEV_EDITION");
+        }
+
+        #[test]
+        fn sr_dev_edition_unknown_value_ignored() {
+            let _guard = ENV_LOCK.lock().unwrap();
+            std::env::set_var("SR_DEV_EDITION", "enterprise");
+            assert_eq!(dev_override_edition(), None);
+            std::env::remove_var("SR_DEV_EDITION");
+        }
+    }
 }