lnd.xprv/channeldb/migration_01_to_11/zpay32/invoice.go
Conner Fromknecht 213c51a281
channeldb/migration_01_to_11: isolate zpay32 decoding
This commit copies over the relevant zpay32 decoding logic to ensure
that our prior migrations aren't affected by upcoming changes to the
zpay32 package, most notably changes to the default final_cltv_expiry
and expiry values.
2020-07-24 13:13:47 -07:00

375 lines
12 KiB
Go

package zpay32
import (
"errors"
"fmt"
"time"
"github.com/btcsuite/btcd/btcec"
"github.com/btcsuite/btcd/chaincfg"
"github.com/btcsuite/btcutil"
"github.com/lightningnetwork/lnd/lnwire"
)
const (
// mSatPerBtc is the number of millisatoshis in 1 BTC.
mSatPerBtc = 100000000000
// signatureBase32Len is the number of 5-bit groups needed to encode
// the 512 bit signature + 8 bit recovery ID.
signatureBase32Len = 104
// timestampBase32Len is the number of 5-bit groups needed to encode
// the 35-bit timestamp.
timestampBase32Len = 7
// hashBase32Len is the number of 5-bit groups needed to encode a
// 256-bit hash. Note that the last group will be padded with zeroes.
hashBase32Len = 52
// pubKeyBase32Len is the number of 5-bit groups needed to encode a
// 33-byte compressed pubkey. Note that the last group will be padded
// with zeroes.
pubKeyBase32Len = 53
// hopHintLen is the number of bytes needed to encode the hop hint of a
// single private route.
hopHintLen = 51
// The following byte values correspond to the supported field types.
// The field name is the character representing that 5-bit value in the
// bech32 string.
// fieldTypeP is the field containing the payment hash.
fieldTypeP = 1
// fieldTypeD contains a short description of the payment.
fieldTypeD = 13
// fieldTypeN contains the pubkey of the target node.
fieldTypeN = 19
// fieldTypeH contains the hash of a description of the payment.
fieldTypeH = 23
// fieldTypeX contains the expiry in seconds of the invoice.
fieldTypeX = 6
// fieldTypeF contains a fallback on-chain address.
fieldTypeF = 9
// fieldTypeR contains extra routing information.
fieldTypeR = 3
// fieldTypeC contains an optional requested final CLTV delta.
fieldTypeC = 24
// fieldType9 contains one or more bytes for signaling features
// supported or required by the receiver.
fieldType9 = 5
// fieldTypeS contains a 32-byte payment address, which is a nonce
// included in the final hop's payload to prevent intermediaries from
// probing the recipient.
fieldTypeS = 16
// maxInvoiceLength is the maximum total length an invoice can have.
// This is chosen to be the maximum number of bytes that can fit into a
// single QR code: https://en.wikipedia.org/wiki/QR_code#Storage
maxInvoiceLength = 7089
// DefaultInvoiceExpiry is the default expiry duration from the creation
// timestamp if expiry is set to zero.
DefaultInvoiceExpiry = time.Hour
)
var (
// ErrInvoiceTooLarge is returned when an invoice exceeds
// maxInvoiceLength.
ErrInvoiceTooLarge = errors.New("invoice is too large")
// ErrInvalidFieldLength is returned when a tagged field was specified
// with a length larger than the left over bytes of the data field.
ErrInvalidFieldLength = errors.New("invalid field length")
// ErrBrokenTaggedField is returned when the last tagged field is
// incorrectly formatted and doesn't have enough bytes to be read.
ErrBrokenTaggedField = errors.New("last tagged field is broken")
)
// MessageSigner is passed to the Encode method to provide a signature
// corresponding to the node's pubkey.
type MessageSigner struct {
// SignCompact signs the passed hash with the node's privkey. The
// returned signature should be 65 bytes, where the last 64 are the
// compact signature, and the first one is a header byte. This is the
// format returned by btcec.SignCompact.
SignCompact func(hash []byte) ([]byte, error)
}
// Invoice represents a decoded invoice, or to-be-encoded invoice. Some of the
// fields are optional, and will only be non-nil if the invoice this was parsed
// from contains that field. When encoding, only the non-nil fields will be
// added to the encoded invoice.
type Invoice struct {
// Net specifies what network this Lightning invoice is meant for.
Net *chaincfg.Params
// MilliSat specifies the amount of this invoice in millisatoshi.
// Optional.
MilliSat *lnwire.MilliSatoshi
// Timestamp specifies the time this invoice was created.
// Mandatory
Timestamp time.Time
// PaymentHash is the payment hash to be used for a payment to this
// invoice.
PaymentHash *[32]byte
// PaymentAddr is the payment address to be used by payments to prevent
// probing of the destination.
PaymentAddr *[32]byte
// Destination is the public key of the target node. This will always
// be set after decoding, and can optionally be set before encoding to
// include the pubkey as an 'n' field. If this is not set before
// encoding then the destination pubkey won't be added as an 'n' field,
// and the pubkey will be extracted from the signature during decoding.
Destination *btcec.PublicKey
// minFinalCLTVExpiry is the value that the creator of the invoice
// expects to be used for the CLTV expiry of the HTLC extended to it in
// the last hop.
//
// NOTE: This value is optional, and should be set to nil if the
// invoice creator doesn't have a strong requirement on the CLTV expiry
// of the final HTLC extended to it.
//
// This field is un-exported and can only be read by the
// MinFinalCLTVExpiry() method. By forcing callers to read via this
// method, we can easily enforce the default if not specified.
minFinalCLTVExpiry *uint64
// Description is a short description of the purpose of this invoice.
// Optional. Non-nil iff DescriptionHash is nil.
Description *string
// DescriptionHash is the SHA256 hash of a description of the purpose of
// this invoice.
// Optional. Non-nil iff Description is nil.
DescriptionHash *[32]byte
// expiry specifies the timespan this invoice will be valid.
// Optional. If not set, a default expiry of 60 min will be implied.
//
// This field is unexported and can be read by the Expiry() method. This
// method makes sure the default expiry time is returned in case the
// field is not set.
expiry *time.Duration
// FallbackAddr is an on-chain address that can be used for payment in
// case the Lightning payment fails.
// Optional.
FallbackAddr btcutil.Address
// RouteHints represents one or more different route hints. Each route
// hint can be individually used to reach the destination. These usually
// represent private routes.
//
// NOTE: This is optional.
RouteHints [][]HopHint
// Features represents an optional field used to signal optional or
// required support for features by the receiver.
Features *lnwire.FeatureVector
}
// Amount is a functional option that allows callers of NewInvoice to set the
// amount in millisatoshis that the Invoice should encode.
func Amount(milliSat lnwire.MilliSatoshi) func(*Invoice) {
return func(i *Invoice) {
i.MilliSat = &milliSat
}
}
// Destination is a functional option that allows callers of NewInvoice to
// explicitly set the pubkey of the Invoice's destination node.
func Destination(destination *btcec.PublicKey) func(*Invoice) {
return func(i *Invoice) {
i.Destination = destination
}
}
// Description is a functional option that allows callers of NewInvoice to set
// the payment description of the created Invoice.
//
// NOTE: Must be used if and only if DescriptionHash is not used.
func Description(description string) func(*Invoice) {
return func(i *Invoice) {
i.Description = &description
}
}
// CLTVExpiry is an optional value which allows the receiver of the payment to
// specify the delta between the current height and the HTLC extended to the
// receiver.
func CLTVExpiry(delta uint64) func(*Invoice) {
return func(i *Invoice) {
i.minFinalCLTVExpiry = &delta
}
}
// DescriptionHash is a functional option that allows callers of NewInvoice to
// set the payment description hash of the created Invoice.
//
// NOTE: Must be used if and only if Description is not used.
func DescriptionHash(descriptionHash [32]byte) func(*Invoice) {
return func(i *Invoice) {
i.DescriptionHash = &descriptionHash
}
}
// Expiry is a functional option that allows callers of NewInvoice to set the
// expiry of the created Invoice. If not set, a default expiry of 60 min will
// be implied.
func Expiry(expiry time.Duration) func(*Invoice) {
return func(i *Invoice) {
i.expiry = &expiry
}
}
// FallbackAddr is a functional option that allows callers of NewInvoice to set
// the Invoice's fallback on-chain address that can be used for payment in case
// the Lightning payment fails
func FallbackAddr(fallbackAddr btcutil.Address) func(*Invoice) {
return func(i *Invoice) {
i.FallbackAddr = fallbackAddr
}
}
// RouteHint is a functional option that allows callers of NewInvoice to add
// one or more hop hints that represent a private route to the destination.
func RouteHint(routeHint []HopHint) func(*Invoice) {
return func(i *Invoice) {
i.RouteHints = append(i.RouteHints, routeHint)
}
}
// Features is a functional option that allows callers of NewInvoice to set the
// desired feature bits that are advertised on the invoice. If this option is
// not used, an empty feature vector will automatically be populated.
func Features(features *lnwire.FeatureVector) func(*Invoice) {
return func(i *Invoice) {
i.Features = features
}
}
// PaymentAddr is a functional option that allows callers of NewInvoice to set
// the desired payment address tht is advertised on the invoice.
func PaymentAddr(addr [32]byte) func(*Invoice) {
return func(i *Invoice) {
i.PaymentAddr = &addr
}
}
// NewInvoice creates a new Invoice object. The last parameter is a set of
// variadic arguments for setting optional fields of the invoice.
//
// NOTE: Either Description or DescriptionHash must be provided for the Invoice
// to be considered valid.
func NewInvoice(net *chaincfg.Params, paymentHash [32]byte,
timestamp time.Time, options ...func(*Invoice)) (*Invoice, error) {
invoice := &Invoice{
Net: net,
PaymentHash: &paymentHash,
Timestamp: timestamp,
}
for _, option := range options {
option(invoice)
}
// If no features were set, we'll populate an empty feature vector.
if invoice.Features == nil {
invoice.Features = lnwire.NewFeatureVector(
nil, lnwire.Features,
)
}
if err := validateInvoice(invoice); err != nil {
return nil, err
}
return invoice, nil
}
// Expiry returns the expiry time for this invoice. If expiry time is not set
// explicitly, the default 3600 second expiry will be returned.
func (invoice *Invoice) Expiry() time.Duration {
if invoice.expiry != nil {
return *invoice.expiry
}
// If no expiry is set for this invoice, default is 3600 seconds.
return DefaultInvoiceExpiry
}
// MinFinalCLTVExpiry returns the minimum final CLTV expiry delta as specified
// by the creator of the invoice. This value specifies the delta between the
// current height and the expiry height of the HTLC extended in the last hop.
func (invoice *Invoice) MinFinalCLTVExpiry() uint64 {
if invoice.minFinalCLTVExpiry != nil {
return *invoice.minFinalCLTVExpiry
}
return DefaultFinalCLTVDelta
}
// validateInvoice does a sanity check of the provided Invoice, making sure it
// has all the necessary fields set for it to be considered valid by BOLT-0011.
func validateInvoice(invoice *Invoice) error {
// The net must be set.
if invoice.Net == nil {
return fmt.Errorf("net params not set")
}
// The invoice must contain a payment hash.
if invoice.PaymentHash == nil {
return fmt.Errorf("no payment hash found")
}
// Either Description or DescriptionHash must be set, not both.
if invoice.Description != nil && invoice.DescriptionHash != nil {
return fmt.Errorf("both description and description hash set")
}
if invoice.Description == nil && invoice.DescriptionHash == nil {
return fmt.Errorf("neither description nor description hash set")
}
// Check that we support the field lengths.
if len(invoice.PaymentHash) != 32 {
return fmt.Errorf("unsupported payment hash length: %d",
len(invoice.PaymentHash))
}
if invoice.DescriptionHash != nil && len(invoice.DescriptionHash) != 32 {
return fmt.Errorf("unsupported description hash length: %d",
len(invoice.DescriptionHash))
}
if invoice.Destination != nil &&
len(invoice.Destination.SerializeCompressed()) != 33 {
return fmt.Errorf("unsupported pubkey length: %d",
len(invoice.Destination.SerializeCompressed()))
}
// Ensure that all invoices have feature vectors.
if invoice.Features == nil {
return fmt.Errorf("missing feature vector")
}
return nil
}