mirror of
https://github.com/lightningnetwork/lnd.git
synced 2024-11-19 09:53:54 +01:00
bba9b665ef
We now enforce that the site of all revocation pre-images+hashes (used for HTLC’s) are now 32-bytes. Additionally, all payment pre-images are now required to be 32-bytes not he wire. There also exists a Script level enforcement of the payment pre-image size at a lower level. This commit serves to unify the sizes of all hashes/pre-images across the codebase.
591 lines
15 KiB
Go
591 lines
15 KiB
Go
package lnwire
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import (
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"bytes"
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"encoding/binary"
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"fmt"
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"io"
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"github.com/roasbeef/btcd/btcec"
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"github.com/roasbeef/btcd/txscript"
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"github.com/roasbeef/btcd/wire"
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"github.com/roasbeef/btcutil"
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)
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// MaxSliceLength is the maximum allowed lenth for any opaque byte slices in
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// the wire protocol.
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const MaxSliceLength = 65535
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// PkScript is simple type definition which represents a raw serialized public
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// key script.
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type PkScript []byte
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// HTLCKey is an identifier used to uniquely identify any HTLC's transmitted
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// between Alice and Bob. In order to cancel, timeout, or settle HTLC's this
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// identifier should be used to allow either side to easily locate and modify
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// any staged or pending HTLCs.
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// TODO(roasbeef): change to HTLCIdentifier?
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type HTLCKey int64
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// CommitHeight is an integer which represents the highest HTLCKey seen by
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// either side within their commitment transaction. Any addition to the pending,
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// HTLC lists on either side will increment this height. As a result this value
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// should always be monotonically increasing. Any CommitSignature or
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// CommitRevocation messages will reference a value for the commitment height
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// up to which it covers. HTLC's are only explicltly excluded by sending
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// HTLCReject messages referencing a particular HTLCKey.
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type CommitHeight uint64
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// CreditsAmount are the native currency unit used within the Lightning Network.
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// Credits are denominated in sub-satoshi amounts, so micro-satoshis (1/1000).
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// This value is purposefully signed in order to allow the expression of negative
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// fees.
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//
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// "In any science-fiction movie, anywhere in the galaxy, currency is referred
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// to as 'credits.'"
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// --Sam Humphries. Ebert, Roger (1999). Ebert's bigger little movie
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// glossary. Andrews McMeel. p. 172.
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//
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// https://en.wikipedia.org/wiki/List_of_fictional_currencies
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// https://en.wikipedia.org/wiki/Fictional_currency#Trends_in_the_use_of_fictional_currencies
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// http://tvtropes.org/pmwiki/pmwiki.php/Main/WeWillSpendCreditsInTheFuture
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// US Display format: 1 BTC = 100,000,000'000 XCB
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// Or in BTC = 1.00000000'000
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// Credits (XCB, accountants should use XCB :^)
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type CreditsAmount int64
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// ToSatoshi converts an amount in Credits to the coresponding amount
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// expressed in Satoshis.
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//
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// NOTE: This function rounds down by default (floor).
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func (c CreditsAmount) ToSatoshi() int64 {
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return int64(c / 1000)
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}
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// writeElement is a one-stop shop to write the big endian representation of
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// any element which is to be serialized for the wire protocol. The passed
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// io.Writer should be backed by an appropriatly sized byte slice, or be able
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// to dynamically expand to accomdate additional data.
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//
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// TODO(roasbeef): this should eventually draw from a buffer pool for
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// serialization.
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// TODO(roasbeef): switch to var-ints for all?
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func writeElement(w io.Writer, element interface{}) error {
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switch e := element.(type) {
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case uint8:
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var b [1]byte
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b[0] = byte(e)
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if _, err := w.Write(b[:]); err != nil {
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return err
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}
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case uint16:
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var b [2]byte
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binary.BigEndian.PutUint16(b[:], uint16(e))
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if _, err := w.Write(b[:]); err != nil {
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return err
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}
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case CreditsAmount:
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if err := binary.Write(w, binary.BigEndian, int64(e)); err != nil {
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return err
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}
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case uint32:
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var b [4]byte
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binary.BigEndian.PutUint32(b[:], uint32(e))
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if _, err := w.Write(b[:]); err != nil {
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return err
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}
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case uint64:
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var b [8]byte
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binary.BigEndian.PutUint64(b[:], uint64(e))
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if _, err := w.Write(b[:]); err != nil {
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return err
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}
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case HTLCKey:
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if err := binary.Write(w, binary.BigEndian, int64(e)); err != nil {
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return err
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}
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case btcutil.Amount:
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if err := binary.Write(w, binary.BigEndian, int64(e)); err != nil {
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return err
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}
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case *btcec.PublicKey:
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var b [33]byte
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serializedPubkey := e.SerializeCompressed()
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copy(b[:], serializedPubkey)
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// TODO(roasbeef): use WriteVarBytes here?
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if _, err := w.Write(b[:]); err != nil {
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return err
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}
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case []uint64:
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// Enforce a max number of elements in a uint64 slice.
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numItems := len(e)
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if numItems > 65535 {
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return fmt.Errorf("Too many []uint64s")
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}
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// First write out the the number of elements in the slice as a
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// length prefix.
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if err := writeElement(w, uint16(numItems)); err != nil {
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return err
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}
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// After the prefix detailing the number of elements, write out
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// each uint64 in series.
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for i := 0; i < numItems; i++ {
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if err := writeElement(w, e[i]); err != nil {
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return err
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}
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}
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case []*btcec.Signature:
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// Enforce a sane number for the maximum number of signatures.
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numSigs := len(e)
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if numSigs > 127 {
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return fmt.Errorf("Too many signatures!")
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}
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// First write out the the number of elements in the slice as a
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// length prefix.
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if err := writeElement(w, uint8(numSigs)); err != nil {
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return err
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}
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// After the prefix detailing the number of elements, write out
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// each signature in series.
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for i := 0; i < numSigs; i++ {
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if err := writeElement(w, e[i]); err != nil {
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return err
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}
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}
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case *btcec.Signature:
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sig := e.Serialize()
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if len(sig) > 73 {
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return fmt.Errorf("Signature too long!")
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}
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if err := wire.WriteVarBytes(w, 0, sig); err != nil {
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return err
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}
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case *wire.ShaHash:
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if _, err := w.Write(e[:]); err != nil {
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return err
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}
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case [][32]byte:
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// First write out the number of elements in the slice.
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sliceSize := len(e)
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if err := writeElement(w, uint16(sliceSize)); err != nil {
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return err
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}
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// Then write each out sequentially.
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for _, element := range e {
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if err := writeElement(w, element); err != nil {
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return err
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}
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}
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case [32]byte:
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// TODO(roasbeef): should be factor out to caller logic...
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if _, err := w.Write(e[:]); err != nil {
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return err
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}
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case wire.BitcoinNet:
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var b [4]byte
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binary.BigEndian.PutUint32(b[:], uint32(e))
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if _, err := w.Write(b[:]); err != nil {
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return err
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}
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case []byte:
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// Enforce the maxmium length of all slices used in the wire
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// protocol.
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sliceLength := len(e)
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if sliceLength > MaxSliceLength {
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return fmt.Errorf("Slice length too long!")
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}
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if err := wire.WriteVarBytes(w, 0, e); err != nil {
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return err
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}
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case PkScript:
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// Make sure it's P2PKH or P2SH size or less.
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scriptLength := len(e)
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if scriptLength > 25 {
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return fmt.Errorf("PkScript too long!")
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}
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if err := wire.WriteVarBytes(w, 0, e); err != nil {
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return err
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}
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case string:
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strlen := len(e)
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if strlen > MaxSliceLength {
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return fmt.Errorf("String too long!")
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}
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if err := wire.WriteVarString(w, 0, e); err != nil {
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return err
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}
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case []*wire.TxIn:
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// Write the size (1-byte)
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if len(e) > 127 {
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return fmt.Errorf("Too many txins")
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}
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// Write out the number of txins.
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if err := writeElement(w, uint8(len(e))); err != nil {
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return err
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}
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// Append the actual TxIns (Size: NumOfTxins * 36)
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// During serialization we leave out the sequence number to
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// eliminate any funny business.
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for _, in := range e {
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if err := writeElement(w, in); err != nil {
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return err
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}
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}
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case *wire.TxIn:
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// First write out the previous txid.
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var h [32]byte
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copy(h[:], e.PreviousOutPoint.Hash[:])
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if _, err := w.Write(h[:]); err != nil {
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return err
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}
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// Then the exact index of the previous out point.
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var idx [4]byte
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binary.BigEndian.PutUint32(idx[:], e.PreviousOutPoint.Index)
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if _, err := w.Write(idx[:]); err != nil {
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return err
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}
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case *wire.OutPoint:
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// TODO(roasbeef): consolidate with above
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// First write out the previous txid.
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var h [32]byte
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copy(h[:], e.Hash[:])
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if _, err := w.Write(h[:]); err != nil {
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return err
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}
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// Then the exact index of this output.
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var idx [4]byte
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binary.BigEndian.PutUint32(idx[:], e.Index)
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if _, err := w.Write(idx[:]); err != nil {
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return err
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}
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// TODO(roasbeef): *MsgTx
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default:
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return fmt.Errorf("Unknown type in writeElement: %T", e)
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}
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return nil
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}
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// writeElements is writes each element in the elements slice to the passed
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// io.Writer using writeElement.
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func writeElements(w io.Writer, elements ...interface{}) error {
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for _, element := range elements {
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err := writeElement(w, element)
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if err != nil {
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return err
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}
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}
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return nil
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}
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// readElement is a one-stop utility function to deserialize any datastructure
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// encoded using the serialization format of lnwire.
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func readElement(r io.Reader, element interface{}) error {
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var err error
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switch e := element.(type) {
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case *uint8:
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var b [1]uint8
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if _, err := r.Read(b[:]); err != nil {
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return err
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}
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*e = b[0]
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case *uint16:
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var b [2]byte
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if _, err := io.ReadFull(r, b[:]); err != nil {
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return err
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}
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*e = binary.BigEndian.Uint16(b[:])
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case *CreditsAmount:
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var b [8]byte
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if _, err := io.ReadFull(r, b[:]); err != nil {
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return err
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}
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*e = CreditsAmount(int64(binary.BigEndian.Uint64(b[:])))
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case *uint32:
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var b [4]byte
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if _, err := io.ReadFull(r, b[:]); err != nil {
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return err
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}
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*e = binary.BigEndian.Uint32(b[:])
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case *uint64:
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var b [8]byte
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if _, err := io.ReadFull(r, b[:]); err != nil {
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return err
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}
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*e = binary.BigEndian.Uint64(b[:])
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case *HTLCKey:
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var b [8]byte
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if _, err := io.ReadFull(r, b[:]); err != nil {
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return err
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}
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*e = HTLCKey(int64(binary.BigEndian.Uint64(b[:])))
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case *btcutil.Amount:
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var b [8]byte
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if _, err := io.ReadFull(r, b[:]); err != nil {
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return err
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}
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*e = btcutil.Amount(int64(binary.BigEndian.Uint64(b[:])))
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case **wire.ShaHash:
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var b wire.ShaHash
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if _, err := io.ReadFull(r, b[:]); err != nil {
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return err
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}
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*e = &b
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case **btcec.PublicKey:
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var b [33]byte
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if _, err = io.ReadFull(r, b[:]); err != nil {
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return err
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}
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pubKey, err := btcec.ParsePubKey(b[:], btcec.S256())
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if err != nil {
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return err
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}
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*e = pubKey
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case *[]uint64:
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var numItems uint16
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if err := readElement(r, &numItems); err != nil {
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return err
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}
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// if numItems > 65535 {
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// return fmt.Errorf("Too many items in []uint64")
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// }
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// Read the number of items
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var items []uint64
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for i := uint16(0); i < numItems; i++ {
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var item uint64
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err = readElement(r, &item)
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if err != nil {
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return err
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}
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items = append(items, item)
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}
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*e = items
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case *[]*btcec.Signature:
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var numSigs uint8
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err = readElement(r, &numSigs)
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if err != nil {
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return err
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}
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if numSigs > 127 {
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return fmt.Errorf("Too many signatures!")
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}
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// Read that number of signatures
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var sigs []*btcec.Signature
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for i := uint8(0); i < numSigs; i++ {
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sig := new(btcec.Signature)
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err = readElement(r, &sig)
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if err != nil {
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return err
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}
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sigs = append(sigs, sig)
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}
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*e = sigs
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return nil
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case **btcec.Signature:
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sigBytes, err := wire.ReadVarBytes(r, 0, 73, "signature")
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if err != nil {
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return err
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}
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sig, err := btcec.ParseSignature(sigBytes, btcec.S256())
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if err != nil {
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return err
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}
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*e = sig
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case *[][32]byte:
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// How many to read
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var sliceSize uint16
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err = readElement(r, &sliceSize)
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if err != nil {
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return err
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}
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data := make([][32]byte, 0, sliceSize)
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// Append the actual
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for i := uint16(0); i < sliceSize; i++ {
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var element [32]byte
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err = readElement(r, &element)
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if err != nil {
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return err
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}
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data = append(data, element)
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}
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*e = data
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case *[32]byte:
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if _, err = io.ReadFull(r, e[:]); err != nil {
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return err
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}
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case *wire.BitcoinNet:
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var b [4]byte
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if _, err := io.ReadFull(r, b[:]); err != nil {
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return err
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}
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*e = wire.BitcoinNet(binary.BigEndian.Uint32(b[:]))
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return nil
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case *[]byte:
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bytes, err := wire.ReadVarBytes(r, 0, MaxSliceLength, "byte slice")
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if err != nil {
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return err
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}
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*e = bytes
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case *PkScript:
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pkScript, err := wire.ReadVarBytes(r, 0, 25, "pkscript")
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if err != nil {
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return err
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}
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*e = pkScript
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case *string:
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str, err := wire.ReadVarString(r, 0)
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if err != nil {
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return err
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}
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*e = str
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case *[]*wire.TxIn:
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// Read the size (1-byte number of txins)
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var numScripts uint8
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if err := readElement(r, &numScripts); err != nil {
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return err
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}
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if numScripts > 127 {
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return fmt.Errorf("Too many txins")
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}
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// Append the actual TxIns
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txins := make([]*wire.TxIn, 0, numScripts)
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for i := uint8(0); i < numScripts; i++ {
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outpoint := new(wire.OutPoint)
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txin := wire.NewTxIn(outpoint, nil, nil)
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if err := readElement(r, &txin); err != nil {
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return err
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}
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txins = append(txins, txin)
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}
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*e = txins
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case **wire.TxIn:
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// Hash
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var h [32]byte
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if _, err = io.ReadFull(r, h[:]); err != nil {
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return err
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}
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hash, err := wire.NewShaHash(h[:])
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if err != nil {
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return err
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}
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(*e).PreviousOutPoint.Hash = *hash
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// Index
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var idxBytes [4]byte
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_, err = io.ReadFull(r, idxBytes[:])
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if err != nil {
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return err
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}
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(*e).PreviousOutPoint.Index = binary.BigEndian.Uint32(idxBytes[:])
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return nil
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case **wire.OutPoint:
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// TODO(roasbeef): consolidate with above
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var h [32]byte
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if _, err = io.ReadFull(r, h[:]); err != nil {
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return err
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}
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hash, err := wire.NewShaHash(h[:])
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if err != nil {
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return err
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}
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// Index
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var idxBytes [4]byte
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_, err = io.ReadFull(r, idxBytes[:])
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if err != nil {
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return err
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}
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index := binary.BigEndian.Uint32(idxBytes[:])
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*e = wire.NewOutPoint(hash, index)
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default:
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return fmt.Errorf("Unknown type in readElement: %T", e)
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}
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return nil
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}
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// readElements deserializes a variable number of elements into the passed
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// io.Reader, with each element being deserialized according to the readElement
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// function.
|
|
func readElements(r io.Reader, elements ...interface{}) error {
|
|
for _, element := range elements {
|
|
err := readElement(r, element)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// validatePkScript determines if the passed pkScript is a valid pkScript within
|
|
// lnwire. The only pkScript templates that lnwire currently allows are:
|
|
// P2SH, P2WSH, P2PKH, and P2WKH.
|
|
func isValidPkScript(pkScript PkScript) bool {
|
|
// A nil pkScript is obviously invalid.
|
|
if pkScript == nil {
|
|
return false
|
|
}
|
|
|
|
switch len(pkScript) {
|
|
case 25:
|
|
// A valid p2pkh script must be exactly 25 bytes. It must begin
|
|
// with the define prefix, and end with the define suffix.
|
|
p2pkhPrefix := []byte{txscript.OP_DUP, txscript.OP_HASH160}
|
|
p2pkhSuffix := []byte{txscript.OP_EQUALVERIFY, txscript.OP_CHECKSIG,
|
|
txscript.OP_DATA_20}
|
|
if !bytes.Equal(pkScript[0:3], p2pkhPrefix) ||
|
|
!bytes.Equal(pkScript[23:25], p2pkhSuffix) {
|
|
return false
|
|
}
|
|
case 22:
|
|
// P2WKH
|
|
// A valid P2WKH script must be exactly 22 bytes, with the first
|
|
// two op codes being an OP_0 marking a version zero witness
|
|
// program, and the second byte being a 20 byte push data.
|
|
if pkScript[0] != txscript.OP_0 ||
|
|
pkScript[1] != txscript.OP_DATA_20 {
|
|
return false
|
|
}
|
|
case 23:
|
|
// A valid P2SH script must begin with OP_HASH160 PUSHDATA(20),
|
|
// contain 20 bytes, then end with an OP_EQUAL.
|
|
p2shPrefix := []byte{txscript.OP_HASH160, txscript.OP_DATA_20}
|
|
p2shSuffix := []byte{txscript.OP_EQUAL}
|
|
if !bytes.Equal(pkScript[0:2], p2shPrefix) ||
|
|
!bytes.Equal(pkScript[22:23], p2shSuffix) {
|
|
return false
|
|
}
|
|
case 34:
|
|
// A P2WSH script must be exactly 34 bytes, with the first two
|
|
// op codes being an OP_0 marking a version zero witness program,
|
|
// and the second byte being a 32 byte push data.
|
|
if pkScript[0] != txscript.OP_0 ||
|
|
pkScript[1] != txscript.OP_DATA_32 {
|
|
return false
|
|
}
|
|
default:
|
|
return false
|
|
}
|
|
|
|
return true
|
|
}
|