ee7ff1b77f
Transport padding (s4) crashed the whole process with "index out of range" in RoutineSequentialSender on the first data packet: InputPacket/InputPackets sized elem.buffer without headroom for the in-buffer right-shift that prepends the random prefix. - send.go: reserve paddings.transport in both injection-path allocLength computations; replace the manual backward byte loop with an overlap-safe copy; defensively grow the buffer (pool-backed) if it still lacks headroom, dropping packets that cannot fit a single WG message instead of overrunning. - receive.go: drop the rxBytes/timers block duplicated by the AWG re-graft (rx accounting was doubled, keepKeyFreshReceiving fired twice per batch). - send.go: swap jmin/jmax when configured inverted (UAPI validates the fields only individually; a swapped pair panicked rand.Int with a non-positive bound on the first handshake). - obf*.go: bound obfuscator length args to [0, MaxMessageSize] (negative panicked slice bounds, huge ones OOMed the handshake). - magic-header.go: widen to int64 before end-start+1 so a full-range header cannot wrap to a zero rand.Int bound. Tests: transport_padding_test.go reproduces the on-device crash byte-for-byte (red on the previous commit, green now) across both injection paths and the tun path; obf_guards_test.go pins the config-value guards.
65 lines
1.3 KiB
Go
65 lines
1.3 KiB
Go
package device
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import (
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"crypto/rand"
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"errors"
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"fmt"
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"math/big"
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"strconv"
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"strings"
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)
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type magicHeader struct {
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start uint32
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end uint32
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}
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func newMagicHeader(spec string) (*magicHeader, error) {
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parts := strings.Split(spec, "-")
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if len(parts) < 1 || len(parts) > 2 {
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return nil, errors.New("bad format")
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}
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start, err := strconv.ParseUint(parts[0], 10, 32)
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if err != nil {
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return nil, fmt.Errorf("failed to parse %s: %w", parts[0], err)
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}
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var end uint64
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if len(parts) > 1 {
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end, err = strconv.ParseUint(parts[1], 10, 32)
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if err != nil {
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return nil, fmt.Errorf("failed to parse %s: %w", parts[1], err)
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}
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} else {
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end = start
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}
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if end < start {
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return nil, errors.New("wrong range specified")
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}
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return &magicHeader{
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start: uint32(start),
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end: uint32(end),
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}, nil
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}
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func (h *magicHeader) GenSpec() string {
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if h.start == h.end {
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return fmt.Sprintf("%d", h.start)
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}
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return fmt.Sprintf("%d-%d", h.start, h.end)
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}
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func (h *magicHeader) Validate(val uint32) bool {
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return h.start <= val && val <= h.end
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}
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func (h *magicHeader) Generate() uint32 {
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// Widen before arithmetic: end-start+1 in uint32 wraps to 0 for the
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// full 0..2^32-1 range, which would panic rand.Int (bound <= 0).
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high := int64(h.end) - int64(h.start) + 1
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r, _ := rand.Int(rand.Reader, big.NewInt(high))
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return h.start + uint32(r.Int64())
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}
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