Apply send cookies as a delta; judge NAT64/6to4 addresses by the IPv4 they carry

crates-server/yaak-send-proxy/README.md

@@ -39,6 +39,7 @@ arguments; `--help` lists them all.
 | `--allow-private-networks` | off | Let sends reach private, loopback and link-local addresses. **Off by default; see below.** |
 | `--allow-hosts` | empty | Only these hosts (`api.example.com`, `*.example.com`). Empty means any host not denied. |
 | `--deny-hosts` | empty | Never these hosts. Checked before the allow list. |
+| `--nat64-prefixes` | empty | Network-specific NAT64 prefixes (`/96`) whose embedded IPv4 should be judged; the well-known and local-use prefixes always are. |
 | `--max-request-bytes` | 16 MiB | Largest rendered request accepted from the tab. |
 | `--max-response-bytes` | 64 MiB | Largest upstream body relayed before the send is cut off. |
 | `--max-timeout-secs` | 60 | Ceiling on a send's timeout; a request asking for more (or none) gets this. |
@@ -55,7 +56,9 @@ sits on. So by default it refuses to connect to:
 - loopback (`127/8`, `::1`), private (`10/8`, `172.16/12`, `192.168/16`,
   `fc00::/7`), link-local (`169.254/16` — where cloud metadata lives — and
   `fe80::/10`), carrier-grade NAT, multicast, reserved and unspecified ranges,
-  and IPv4 addresses tunnelled inside IPv6 forms (`::ffff:a.b.c.d`, NAT64);
+  and IPv4 addresses carried inside IPv6 forms (`::ffff:a.b.c.d`, the
+  well-known and local-use NAT64 prefixes, 6to4 — plus any NAT64 prefix you
+  name with `--nat64-prefixes`);
 - anything not `http://` or `https://`.
 
 The check runs **on the resolved addresses, after DNS**, for every hop of a

crates-server/yaak-send-proxy/src/config.rs

@@ -49,6 +49,13 @@ pub struct Config {
     #[arg(long, env = "YAAK_PROXY_DENY_HOSTS", value_delimiter = ',')]
     pub deny_hosts: Vec<String>,
 
+    /// NAT64 prefixes (/96) in use on this network, comma-separated, e.g. `2001:db8:64::`. The
+    /// well-known (64:ff9b::/96) and local-use (64:ff9b:1::/48) prefixes are always recognised;
+    /// a network-specific prefix has to be named here or an IPv6 address under it could reach
+    /// an internal IPv4 host through the translator.
+    #[arg(long, env = "YAAK_PROXY_NAT64_PREFIXES", value_delimiter = ',')]
+    pub nat64_prefixes: Vec<std::net::Ipv6Addr>,
+
     /// Largest request the proxy accepts from the tab (the rendered request JSON, body included).
     #[arg(long, env = "YAAK_PROXY_MAX_REQUEST_BYTES", default_value_t = 16 * 1024 * 1024)]
     pub max_request_bytes: usize,

crates-server/yaak-send-proxy/src/guard.rs

@@ -26,6 +26,9 @@ pub struct DestinationPolicy {
     allow_private_networks: bool,
     allow_hosts: Vec<HostPattern>,
     deny_hosts: Vec<HostPattern>,
+    /// NAT64 prefixes (/96) in use on this network beyond the well-known ones. An IPv6
+    /// address under one of these is really an IPv4 destination, and is judged as that.
+    nat64_prefixes: Vec<Ipv6Addr>,
 }
 
 #[derive(Clone, Debug)]
@@ -60,11 +63,13 @@ impl DestinationPolicy {
         allow_private_networks: bool,
         allow_hosts: &[String],
         deny_hosts: &[String],
+        nat64_prefixes: &[Ipv6Addr],
     ) -> Self {
         Self {
             allow_private_networks,
             allow_hosts: allow_hosts.iter().filter_map(|h| HostPattern::parse(h)).collect(),
             deny_hosts: deny_hosts.iter().filter_map(|h| HostPattern::parse(h)).collect(),
+            nat64_prefixes: nat64_prefixes.to_vec(),
         }
     }
 
@@ -105,6 +110,17 @@ impl DestinationPolicy {
         if self.allow_private_networks {
             return Ok(());
         }
+        // An address under a configured NAT64 prefix reaches an IPv4 host; judge that host.
+        if let IpAddr::V6(v6) = ip
+            && self.nat64_prefixes.iter().any(|p| p.segments()[..6] == v6.segments()[..6])
+        {
+            let v4 = trailing_v4(&v6);
+            if let Some(reason) = non_public_v4(v4) {
+                return Err(format!(
+                    "Refusing to connect to {ip} (NAT64 for {v4}): {reason}. This proxy only sends to public addresses"
+                ));
+            }
+        }
         match non_public_reason(ip) {
             Some(reason) => Err(format!(
                 "Refusing to connect to {ip}: {reason}. This proxy only sends to public addresses"
@@ -118,8 +134,10 @@ impl DestinationPolicy {
 ///
 /// Every range here is one a hosted relay must never be talked into reaching: the machine
 /// itself, the network it sits on, and the link-local range where cloud metadata services
-/// (169.254.169.254) live. IPv4 addresses tunnelled inside IPv6 forms are unwrapped and judged
-/// as IPv4, since that is what the socket would connect to.
+/// (169.254.169.254) live. IPv4 addresses carried inside IPv6 forms — IPv4-mapped, the
+/// well-known and local-use NAT64 prefixes, 6to4 — are unwrapped and judged as IPv4, since
+/// that is where the packets end up. A network-specific NAT64 prefix is not knowable here;
+/// see `--nat64-prefix`.
 pub fn non_public_reason(ip: IpAddr) -> Option<&'static str> {
     match ip {
         IpAddr::V4(v4) => non_public_v4(v4),
@@ -127,7 +145,7 @@ pub fn non_public_reason(ip: IpAddr) -> Option<&'static str> {
             if let Some(v4) = v6.to_ipv4_mapped() {
                 return non_public_v4(v4);
             }
-            if let Some(v4) = nat64_embedded_v4(&v6) {
+            if let Some(v4) = embedded_v4(&v6) {
                 return non_public_v4(v4);
             }
             if v6.is_loopback() {
@@ -180,15 +198,33 @@ fn non_public_v4(v4: Ipv4Addr) -> Option<&'static str> {
     }
 }
 
-/// The IPv4 address inside a NAT64 (64:ff9b::/96) address, if this is one.
-fn nat64_embedded_v4(v6: &Ipv6Addr) -> Option<Ipv4Addr> {
+/// The IPv4 address an IPv6 address stands for, when it is one of the standard translation
+/// forms: NAT64 well-known prefix (64:ff9b::/96), NAT64 local-use prefix (64:ff9b:1::/48,
+/// RFC 8215), or 6to4 (2002::/16, where the IPv4 sits in the next 32 bits).
+fn embedded_v4(v6: &Ipv6Addr) -> Option<Ipv4Addr> {
     let s = v6.segments();
     if s[0] == 0x64 && s[1] == 0xff9b && s[2..6].iter().all(|x| *x == 0) {
-        let o = v6.octets();
-        Some(Ipv4Addr::new(o[12], o[13], o[14], o[15]))
-    } else {
-        None
+        return Some(trailing_v4(v6));
     }
+    if s[0] == 0x64 && s[1] == 0xff9b && s[2] == 1 {
+        return Some(trailing_v4(v6));
+    }
+    if s[0] == 0x2002 {
+        return Some(Ipv4Addr::new(
+            (s[1] >> 8) as u8,
+            (s[1] & 0xff) as u8,
+            (s[2] >> 8) as u8,
+            (s[2] & 0xff) as u8,
+        ));
+    }
+    None
+}
+
+/// The last 32 bits of an IPv6 address as an IPv4 address (where every /96 NAT64 prefix
+/// keeps it).
+fn trailing_v4(v6: &Ipv6Addr) -> Ipv4Addr {
+    let o = v6.octets();
+    Ipv4Addr::new(o[12], o[13], o[14], o[15])
 }
 
 /// An [`HttpSender`] that checks each hop's URL against the policy before delegating.
@@ -273,12 +309,26 @@ mod tests {
         }
     }
 
+    #[test]
+    fn a_configured_nat64_prefix_is_judged_by_the_address_it_carries() {
+        // A made-up global prefix, standing in for whatever the network's translator uses
+        let prefix: Ipv6Addr = "2a02:1234:64::".parse().unwrap();
+        let policy = DestinationPolicy::new(false, &[], &[], &[prefix]);
+        assert!(policy.check_ip(ip("2a02:1234:64::a9fe:a9fe")).is_err(), "metadata behind NAT64");
+        assert!(policy.check_ip(ip("2a02:1234:64::0a00:1")).is_err(), "10.0.0.1 behind NAT64");
+        assert!(policy.check_ip(ip("2a02:1234:64::0101:0101")).is_ok(), "1.1.1.1 behind NAT64");
+        // Without the prefix configured the same address is an ordinary global v6, and passes:
+        // that is exactly the gap the option exists to close.
+        let policy = DestinationPolicy::new(false, &[], &[], &[]);
+        assert!(policy.check_ip(ip("2a02:1234:64::a9fe:a9fe")).is_ok());
+    }
+
     #[test]
     fn private_networks_can_be_opted_in() {
-        let policy = DestinationPolicy::new(true, &[], &[]);
+        let policy = DestinationPolicy::new(true, &[], &[], &[]);
         assert!(policy.check_url("http://127.0.0.1/").is_ok());
         assert!(policy.check_url("http://169.254.169.254/").is_ok());
-        let policy = DestinationPolicy::new(false, &[], &[]);
+        let policy = DestinationPolicy::new(false, &[], &[], &[]);
         assert!(policy.check_url("http://127.0.0.1/").is_err());
         assert!(policy.check_url("http://[::1]/").is_err());
         assert!(policy.check_url("http://169.254.169.254/latest/meta-data").is_err());
@@ -290,6 +340,7 @@ mod tests {
             false,
             &["*.example.com".into(), "api.test".into()],
             &["bad.example.com".into()],
+            &[],
         );
         assert!(policy.check_url("https://example.com/").is_ok());
         assert!(policy.check_url("https://a.b.example.com/").is_ok());
@@ -302,7 +353,7 @@ mod tests {
 
     #[test]
     fn only_http_schemes() {
-        let policy = DestinationPolicy::new(true, &[], &[]);
+        let policy = DestinationPolicy::new(true, &[], &[], &[]);
         assert!(policy.check_url("ftp://example.com/").is_err());
         assert!(policy.check_url("file:///etc/passwd").is_err());
         assert!(policy.check_url("https://example.com/").is_ok());

crates-server/yaak-send-proxy/src/main.rs

@@ -53,6 +53,7 @@ async fn main() {
         config.allow_private_networks,
         &config.allow_hosts,
         &config.deny_hosts,
+        &config.nat64_prefixes,
     );
     let state = AppState {
         limits: Arc::new(SendLimits {

crates/yaak-models/src/cookies.rs

@@ -0,0 +1,107 @@
+//! Carrying a send's cookie changes back into a jar.
+//!
+//! A send starts from a snapshot of the jar and hands back the jar as the
+//! transaction left it. Writing that whole result over the jar would also
+//! write over anything the user changed *while* the send was in flight — a
+//! cookie edited or deleted in the jar view, or set by another send. So the
+//! send's contribution is taken as a difference (what it added, changed, or
+//! removed relative to its snapshot) and applied to whatever the jar holds now.
+
+use crate::models::{Cookie, CookieDomain};
+
+/// The identity of a cookie in a jar: two cookies with the same name, domain
+/// and path are the same cookie, whatever their value or attributes.
+type CookieKey = (String, CookieDomain, String);
+
+fn key(c: &Cookie) -> CookieKey {
+    (c.name.clone(), c.domain.clone(), c.path.clone())
+}
+
+/// Apply the changes between `before` (the snapshot a send started from) and
+/// `after` (the jar as the send left it) to `current` (the jar as it is now).
+///
+/// Cookies the send removed are removed; cookies it added or changed replace
+/// their counterpart in `current`, or are appended. Cookies the send did not
+/// touch are left exactly as `current` has them.
+pub fn apply_cookie_changes(
+    current: Vec<Cookie>,
+    before: &[Cookie],
+    after: &[Cookie],
+) -> Vec<Cookie> {
+    let removed: Vec<CookieKey> =
+        before.iter().filter(|b| !after.iter().any(|a| key(a) == key(b))).map(key).collect();
+    let changed: Vec<&Cookie> = after.iter().filter(|a| !before.iter().any(|b| b == *a)).collect();
+
+    let mut result: Vec<Cookie> =
+        current.into_iter().filter(|c| !removed.contains(&key(c))).collect();
+    for cookie in changed {
+        match result.iter_mut().find(|c| key(c) == key(cookie)) {
+            Some(existing) => *existing = cookie.clone(),
+            None => result.push(cookie.clone()),
+        }
+    }
+    result
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::models::CookieExpires;
+
+    fn cookie(name: &str, value: &str) -> Cookie {
+        Cookie {
+            name: name.to_string(),
+            value: value.to_string(),
+            domain: CookieDomain::HostOnly("example.com".to_string()),
+            expires: CookieExpires::SessionEnd,
+            path: "/".to_string(),
+            secure: false,
+            http_only: false,
+            same_site: None,
+        }
+    }
+
+    #[test]
+    fn a_send_that_changed_nothing_leaves_the_jar_alone() {
+        let before = vec![cookie("a", "1")];
+        let current = vec![cookie("a", "edited"), cookie("b", "2")];
+        assert_eq!(apply_cookie_changes(current.clone(), &before, &before), current);
+    }
+
+    #[test]
+    fn additions_and_changes_land_without_touching_concurrent_edits() {
+        let before = vec![cookie("a", "1"), cookie("b", "2")];
+        let after = vec![cookie("a", "1"), cookie("b", "3"), cookie("c", "4")];
+        // Meanwhile the user edited `a` and added `d`.
+        let current = vec![cookie("a", "edited"), cookie("b", "2"), cookie("d", "5")];
+        assert_eq!(
+            apply_cookie_changes(current, &before, &after),
+            vec![
+                cookie("a", "edited"),
+                cookie("b", "3"),
+                cookie("d", "5"),
+                cookie("c", "4")
+            ]
+        );
+    }
+
+    #[test]
+    fn a_cookie_the_send_removed_is_removed() {
+        let before = vec![cookie("a", "1"), cookie("b", "2")];
+        let after = vec![cookie("b", "2")];
+        let current = vec![cookie("a", "1"), cookie("b", "2"), cookie("c", "3")];
+        assert_eq!(
+            apply_cookie_changes(current, &before, &after),
+            vec![cookie("b", "2"), cookie("c", "3")]
+        );
+    }
+
+    #[test]
+    fn a_cookie_the_user_deleted_mid_send_stays_deleted_unless_the_send_set_it() {
+        let before = vec![cookie("a", "1")];
+        let after = vec![cookie("a", "1")]; // untouched by the send
+        assert_eq!(apply_cookie_changes(vec![], &before, &after), vec![]);
+        let after = vec![cookie("a", "fresh")]; // the send set it again
+        assert_eq!(apply_cookie_changes(vec![], &before, &after), vec![cookie("a", "fresh")]);
+    }
+}

crates/yaak-models/src/lib.rs

@@ -10,6 +10,7 @@ use yaak_database::SqlitePool;
 
 pub mod blob_manager;
 pub mod client_db;
+pub mod cookies;
 mod connection_or_tx;
 pub mod error;
 pub mod migrate;

crates/yaak-web/pkg/yaak_web_bg.js

@@ -694,22 +694,22 @@ export function __wbg_versions_215a3ab1c9d5745a(arg0) {
     return ret;
 }
 export function __wbindgen_cast_0000000000000001(arg0, arg1) {
-    // Cast intrinsic for `Closure(Closure { owned: true, function: Function { arguments: [Externref], shim_idx: 1116, ret: Result(Unit), inner_ret: Some(Result(Unit)) }, mutable: true }) -> Externref`.
+    // Cast intrinsic for `Closure(Closure { owned: true, function: Function { arguments: [Externref], shim_idx: 1117, ret: Result(Unit), inner_ret: Some(Result(Unit)) }, mutable: true }) -> Externref`.
     const ret = makeMutClosure(arg0, arg1, wasm_bindgen__convert__closures_____invoke__ha1c2fa93df0107f3);
     return ret;
 }
 export function __wbindgen_cast_0000000000000002(arg0, arg1) {
-    // Cast intrinsic for `Closure(Closure { owned: true, function: Function { arguments: [NamedExternref("Event")], shim_idx: 211, ret: Unit, inner_ret: Some(Unit) }, mutable: true }) -> Externref`.
+    // Cast intrinsic for `Closure(Closure { owned: true, function: Function { arguments: [NamedExternref("Event")], shim_idx: 212, ret: Unit, inner_ret: Some(Unit) }, mutable: true }) -> Externref`.
     const ret = makeMutClosure(arg0, arg1, wasm_bindgen__convert__closures_____invoke__ha7903b6e296dd8f4);
     return ret;
 }
 export function __wbindgen_cast_0000000000000003(arg0, arg1) {
-    // Cast intrinsic for `Closure(Closure { owned: true, function: Function { arguments: [NamedExternref("IDBVersionChangeEvent")], shim_idx: 164, ret: Result(Unit), inner_ret: Some(Result(Unit)) }, mutable: true }) -> Externref`.
+    // Cast intrinsic for `Closure(Closure { owned: true, function: Function { arguments: [NamedExternref("IDBVersionChangeEvent")], shim_idx: 83, ret: Result(Unit), inner_ret: Some(Result(Unit)) }, mutable: true }) -> Externref`.
     const ret = makeMutClosure(arg0, arg1, wasm_bindgen__convert__closures_____invoke__hdf19cb46f9aecb24);
     return ret;
 }
 export function __wbindgen_cast_0000000000000004(arg0, arg1) {
-    // Cast intrinsic for `Closure(Closure { owned: true, function: Function { arguments: [], shim_idx: 209, ret: Unit, inner_ret: Some(Unit) }, mutable: true }) -> Externref`.
+    // Cast intrinsic for `Closure(Closure { owned: true, function: Function { arguments: [], shim_idx: 210, ret: Unit, inner_ret: Some(Unit) }, mutable: true }) -> Externref`.
     const ret = makeMutClosure(arg0, arg1, wasm_bindgen__convert__closures_____invoke__ha1b480b83daa641f);
     return ret;
 }

crates/yaak-web/src/lib.rs

@@ -29,8 +29,10 @@ use serde::{Deserialize, Serialize};
 use std::collections::HashMap;
 use wasm_bindgen::prelude::*;
 use yaak_models::blob_manager::{BlobManager, BodyChunk};
+use yaak_models::cookies::apply_cookie_changes;
 use yaak_models::models::{
-    AnyModel, CookieJar, HttpRequest, HttpResponseEvent, HttpResponseEventData, HttpSendSettings,
+    AnyModel, Cookie, CookieJar, HttpRequest, HttpResponseEvent, HttpResponseEventData,
+    HttpSendSettings,
 };
 use yaak_models::models_ops;
 use yaak_models::query_manager::QueryManager;
@@ -214,6 +216,14 @@ struct ResponseIdReq {
     response_id: String,
 }
 
+#[derive(Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct PersistSendCookiesReq {
+    cookie_jar_id: String,
+    before: Vec<Cookie>,
+    after: Vec<Cookie>,
+}
+
 #[derive(Deserialize)]
 #[serde(rename_all = "camelCase")]
 struct InsertResponseEventsReq {
@@ -341,6 +351,20 @@ fn dispatch(
             )
         }
 
+        // The cookies a send set or cleared, applied to the jar as it is *now* rather than
+        // written over it, so an edit made while the send was in flight survives.
+        "web_persist_send_cookies" => {
+            let req: PersistSendCookiesReq = from_js(payload)?;
+            if req.before == req.after {
+                return to_json(());
+            }
+            let db = host.queries.connect();
+            let jar = db.get_cookie_jar(&req.cookie_jar_id).map_err(js_error)?;
+            let cookies = apply_cookie_changes(jar.cookies.clone(), &req.before, &req.after);
+            db.upsert_cookie_jar(&CookieJar { cookies, ..jar }, source).map_err(js_error)?;
+            to_json(())
+        }
+
         // The tab's half of the send timeline: the events the proxy streamed back, recorded
         // under the response they belong to. Same rows the desktop's send task writes, and the
         // writes fan out to every tab as `model_writes` like any other.

packages/platform/src/web/send.ts

@@ -305,12 +305,14 @@ class TimelineWriter {
   }
 }
 
+/**
+ * Carry the send's cookie changes into the jar. The worker applies them as a
+ * difference against the jar as it is now (see `apply_cookie_changes` in
+ * yaak-models), so an edit made while the send was in flight survives rather
+ * than being written over by the send's stale snapshot.
+ */
 async function persistCookies(db: WorkerConnection, jar: CookieJar, cookies: Cookie[]): Promise<void> {
-  // The desktop compares before writing so a jar edited mid-send isn't clobbered
-  // by an unchanged copy. Structural equality is enough here: cookies are plain
-  // data and the proxy hands back the whole jar.
-  if (JSON.stringify(cookies) === JSON.stringify(jar.cookies)) return;
-  await db.rpc("models_upsert", { model: { ...jar, cookies } });
+  await db.rpc("web_persist_send_cookies", { cookieJarId: jar.id, before: jar.cookies, after: cookies });
 }
 
 /**