+++ /dev/null
-package mainchain
-
-import (
- "encoding/json"
-
- "github.com/vapor/crypto/ed25519/chainkd"
- "github.com/vapor/crypto/sha3pool"
- chainjson "github.com/vapor/encoding/json"
- "github.com/vapor/errors"
- "github.com/vapor/protocol/vm"
-)
-
-type (
- // SignatureWitness is a sign struct
- SignatureWitness struct {
- // Quorum is the number of signatures required.
- Quorum int `json:"quorum"`
-
- // Keys are the identities of the keys to sign with.
- Keys []keyID `json:"keys"`
-
- // Program is the predicate part of the signature program, whose hash is what gets
- // signed. If empty, it is computed during Sign from the outputs
- // and the current input of the transaction.
- Program chainjson.HexBytes `json:"program"`
-
- // Sigs are signatures of Program made from each of the Keys
- // during Sign.
- Sigs []chainjson.HexBytes `json:"signatures"`
- }
-
- keyID struct {
- XPub chainkd.XPub `json:"xpub"`
- DerivationPath []chainjson.HexBytes `json:"derivation_path"`
- }
-)
-
-// ErrEmptyProgram is a type of error
-var ErrEmptyProgram = errors.New("empty signature program")
-
-// Sign populates sw.Sigs with as many signatures of the predicate in
-// sw.Program as it can from the overlapping set of keys in sw.Keys.
-//
-// If sw.Program is empty, it is populated with an _inferred_ predicate:
-// a program committing to aspects of the current
-// transaction. Specifically, the program commits to:
-// - the mintime and maxtime of the transaction (if non-zero)
-// - the outputID of the current input
-// - the assetID, amount, control program of each output.
-func (sw *SignatureWitness) Sign(tpl *Template, index uint32, xprv chainkd.XPrv) error {
- // Compute the predicate to sign. This is either a
- // txsighash program if tpl.AllowAdditional is false (i.e., the tx is complete
- // and no further changes are allowed) or a program enforcing
- // constraints derived from the existing outputs and current input.
- if len(sw.Program) == 0 {
- var err error
- sw.Program, err = buildSigProgram(tpl, tpl.SigningInstructions[index].Position)
- if err != nil {
- return err
- }
- if len(sw.Program) == 0 {
- return ErrEmptyProgram
- }
- }
- if len(sw.Sigs) < len(sw.Keys) {
- // Each key in sw.Keys may produce a signature in sw.Sigs. Make
- // sure there are enough slots in sw.Sigs and that we preserve any
- // sigs already present.
- newSigs := make([]chainjson.HexBytes, len(sw.Keys))
- copy(newSigs, sw.Sigs)
- sw.Sigs = newSigs
- }
- var h [32]byte
- sha3pool.Sum256(h[:], sw.Program)
- for i, keyID := range sw.Keys {
- if len(sw.Sigs[i]) > 0 {
- // Already have a signature for this key
- continue
- }
- path := make([][]byte, len(keyID.DerivationPath))
- for i, p := range keyID.DerivationPath {
- path[i] = p
- }
- if keyID.XPub.String() != xprv.XPub().String() {
- continue
- }
-
- sigBytes := xprv.Sign(h[:])
- // This break is ordered to avoid signing transaction successfully only once for a multiple-sign account
- // that consist of different keys by the same password. Exit immediately when the signature is success,
- // it means that only one signature will be successful in the loop for this multiple-sign account.
- sw.Sigs[i] = sigBytes
- break
- }
- return nil
-}
-
-func (sw SignatureWitness) Materialize(args *[][]byte) error {
- // This is the value of N for the CHECKPREDICATE call. The code
- // assumes that everything already in the arg list before this call
- // to Materialize is input to the signature program, so N is
- // len(*args).
- *args = append(*args, vm.Int64Bytes(int64(len(*args))))
-
- var nsigs int
- for i := 0; i < len(sw.Sigs) && nsigs < sw.Quorum; i++ {
- if len(sw.Sigs[i]) > 0 {
- *args = append(*args, sw.Sigs[i])
- nsigs++
- }
- }
- *args = append(*args, sw.Program)
- return nil
-}
-
-// MarshalJSON convert struct to json
-func (sw SignatureWitness) MarshalJSON() ([]byte, error) {
- obj := struct {
- Type string `json:"type"`
- Quorum int `json:"quorum"`
- Keys []keyID `json:"keys"`
- Sigs []chainjson.HexBytes `json:"signatures"`
- }{
- Type: "signature",
- Quorum: sw.Quorum,
- Keys: sw.Keys,
- Sigs: sw.Sigs,
- }
- return json.Marshal(obj)
-}
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