Stop mislabeling truncated captures as "exact"

internal/proxy/tee.go's teeConn silently drops bytes past
maxCaptureBytes (10 MiB) but callers unconditionally marked the result
"exact" anyway. Confirmed live: proxying a 15 MiB response worked
correctly end-to-end (the client got the full, real 15 MiB - proxying
itself is unbounded, only storage is capped), but the stored history
entry was exactly 10485760 bytes with response_exact=1 still set. For a
tool whose core value proposition is "raw bytes are the source of
truth," a silently truncated capture presented as complete could hide
the very evidence a smuggling or parser-differential investigation is
looking for in the tail of a large body - and give false confidence
that it isn't there.

teeConn.Take() now returns (data, truncated) instead of just data;
truncated is true whenever a Read had to drop bytes because the buffer
was already at cap. Every caller (proxy.go's forward() on both the
request and response side, repeat.go's sendRaw for Repeater/Intruder)
now folds truncated into exact - a truncated capture is never marked
exact - and additionally threads a distinct RequestTruncated/
ResponseTruncated bool through store.Entry, ipc.EntryDetail, and the
TUI, since "truncated" and "reconstructed" (HTTP/2, which never had
wire-exact bytes to begin with) are different situations worth telling
apart: a truncated capture is still real wire bytes, just incomplete,
not a synthesized reconstruction. The detail/repeater views now show
"truncated (hit capture size limit)" specifically rather than lumping
it in with "reconstructed", which would have implied more
transformation happened than actually did.

Schema: history gains request_truncated/response_truncated columns via
the same ALTER-TABLE-and-ignore-duplicate-column pattern already used
for source/flagged, so existing databases upgrade in place.

Verified live: a target server returning a 15 MiB body (over the 10 MiB
cap) proxied through cleanly - full body reached the client - while the
stored entry shows length=10485760, response_exact=0,
response_truncated=1 (previously would have shown response_exact=1);
the TUI's Detail view correctly displays "Response (10485760 bytes,
truncated (hit capture size limit))" instead of "exact".

go build/vet/gofmt/test/mod tidy all clean.

1 files changed, 27 insertions, 9 deletions

diff --git a/internal/store/store.go b/internal/store/store.go
index 4de4fa1..19b71b1 100644
--- a/internal/store/store.go
+++ b/internal/store/store.go
@@ -34,7 +34,9 @@ CREATE TABLE IF NOT EXISTS history (
 	response_exact INTEGER NOT NULL,
 	error          TEXT NOT NULL DEFAULT '',
 	source         TEXT NOT NULL DEFAULT 'proxy',
-	flagged        INTEGER NOT NULL DEFAULT 0
+	flagged        INTEGER NOT NULL DEFAULT 0,
+	request_truncated  INTEGER NOT NULL DEFAULT 0,
+	response_truncated INTEGER NOT NULL DEFAULT 0
 );
 
 CREATE VIRTUAL TABLE IF NOT EXISTS history_fts USING fts5(
@@ -89,6 +91,8 @@ func Open(path string) (*Store, error) {
 	// on databases that already have it.
 	db.Exec("ALTER TABLE history ADD COLUMN source TEXT NOT NULL DEFAULT 'proxy'")
 	db.Exec("ALTER TABLE history ADD COLUMN flagged INTEGER NOT NULL DEFAULT 0")
+	db.Exec("ALTER TABLE history ADD COLUMN request_truncated INTEGER NOT NULL DEFAULT 0")
+	db.Exec("ALTER TABLE history ADD COLUMN response_truncated INTEGER NOT NULL DEFAULT 0")
 	// Backfill history_fts for rows inserted before it existed. A no-op
 	// once caught up, since every Insert keeps both tables in sync.
 	if _, err := db.Exec(`
@@ -121,9 +125,17 @@ type Entry struct {
 	ResponseRaw   []byte // nil if no response was received
 	RequestExact  bool   // true if RequestRaw is wire-exact, false if reconstructed (e.g. HTTP/2)
 	ResponseExact bool
-	Error         string // network/transport error, if the request never got a response
-	Source        string // "proxy" or "repeater"
-	Flagged       bool
+	// Truncated is true when the corresponding *Raw field would have
+	// been an exact capture but hit maxCaptureBytes and had bytes
+	// dropped off the end - distinct from a false *Exact, which also
+	// covers HTTP/2's inherently-reconstructed (never wire-exact to
+	// begin with) captures. Only meaningful when the matching *Exact
+	// field is false; a capture can't be both exact and truncated.
+	RequestTruncated  bool
+	ResponseTruncated bool
+	Error             string // network/transport error, if the request never got a response
+	Source            string // "proxy" or "repeater"
+	Flagged           bool
 }
 
 // Summary is the lightweight metadata used for the history list view -
@@ -164,10 +176,12 @@ func (s *Store) Insert(e *Entry) (int64, error) {
 	res, err := tx.Exec(
 		`INSERT INTO history
 			(started_at, duration_ms, method, scheme, host, path, status_code,
-			 request_raw, response_raw, request_exact, response_exact, error, source)
-		 VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`,
+			 request_raw, response_raw, request_exact, response_exact, error, source,
+			 request_truncated, response_truncated)
+		 VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`,
 		e.StartedAt.UnixMilli(), e.Duration.Milliseconds(), e.Method, e.Scheme, e.Host, e.Path,
 		statusCode, e.RequestRaw, e.ResponseRaw, boolToInt(e.RequestExact), boolToInt(e.ResponseExact), e.Error, source,
+		boolToInt(e.RequestTruncated), boolToInt(e.ResponseTruncated),
 	)
 	if err != nil {
 		return 0, fmt.Errorf("insert history entry: %w", err)
@@ -394,15 +408,17 @@ func (s *Store) Get(id int64) (*Entry, error) {
 	row := s.db.QueryRow(
 		`SELECT id, started_at, duration_ms, method, scheme, host, path,
 		        COALESCE(status_code, 0), request_raw, response_raw,
-		        request_exact, response_exact, error, source, flagged
+		        request_exact, response_exact, error, source, flagged,
+		        request_truncated, response_truncated
 		 FROM history WHERE id = ?`,
 		id,
 	)
 	var e Entry
 	var startedAt, durationMs int64
-	var reqExact, respExact, flagged int
+	var reqExact, respExact, flagged, reqTrunc, respTrunc int
 	if err := row.Scan(&e.ID, &startedAt, &durationMs, &e.Method, &e.Scheme, &e.Host, &e.Path,
-		&e.StatusCode, &e.RequestRaw, &e.ResponseRaw, &reqExact, &respExact, &e.Error, &e.Source, &flagged); err != nil {
+		&e.StatusCode, &e.RequestRaw, &e.ResponseRaw, &reqExact, &respExact, &e.Error, &e.Source, &flagged,
+		&reqTrunc, &respTrunc); err != nil {
 		return nil, fmt.Errorf("get history entry %d: %w", id, err)
 	}
 	e.StartedAt = time.UnixMilli(startedAt)
@@ -410,6 +426,8 @@ func (s *Store) Get(id int64) (*Entry, error) {
 	e.RequestExact = reqExact != 0
 	e.ResponseExact = respExact != 0
 	e.Flagged = flagged != 0
+	e.RequestTruncated = reqTrunc != 0
+	e.ResponseTruncated = respTrunc != 0
 	return &e, nil
 }