94 lines
2.1 KiB
Go
94 lines
2.1 KiB
Go
package smt
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import (
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"bytes"
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"crypto/sha256"
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"encoding/gob"
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"hash"
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"github.com/cosmos/cosmos-sdk/store/types"
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sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
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"github.com/lazyledger/smt"
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"github.com/tendermint/tendermint/crypto/merkle"
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tmmerkle "github.com/tendermint/tendermint/proto/tendermint/crypto"
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)
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type HasherType byte
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const (
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SHA256 HasherType = iota
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)
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const (
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ProofType = "smt"
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)
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type ProofOp struct {
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Root []byte
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Key []byte
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Hasher HasherType
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Proof smt.SparseMerkleProof
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}
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var _ merkle.ProofOperator = (*ProofOp)(nil)
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// NewProofOp returns a ProofOp for a SparseMerkleProof.
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func NewProofOp(root, key []byte, hasher HasherType, proof smt.SparseMerkleProof) *ProofOp {
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return &ProofOp{
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Root: root,
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Key: key,
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Hasher: hasher,
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Proof: proof,
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}
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}
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func (p *ProofOp) Run(args [][]byte) ([][]byte, error) {
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switch len(args) {
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case 0: // non-membership proof
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if !smt.VerifyProof(p.Proof, p.Root, p.Key, []byte{}, getHasher(p.Hasher)) {
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return nil, sdkerrors.Wrapf(types.ErrInvalidProof, "proof did not verify absence of key: %s", p.Key)
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}
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case 1: // membership proof
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if !smt.VerifyProof(p.Proof, p.Root, p.Key, args[0], getHasher(p.Hasher)) {
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return nil, sdkerrors.Wrapf(types.ErrInvalidProof, "proof did not verify existence of key %s with given value %x", p.Key, args[0])
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}
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default:
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return nil, sdkerrors.Wrapf(types.ErrInvalidProof, "args must be length 0 or 1, got: %d", len(args))
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}
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return [][]byte{p.Root}, nil
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}
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func (p *ProofOp) GetKey() []byte {
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return p.Key
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}
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func (p *ProofOp) ProofOp() tmmerkle.ProofOp {
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var data bytes.Buffer
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enc := gob.NewEncoder(&data)
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enc.Encode(p)
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return tmmerkle.ProofOp{
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Type: "smt",
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Key: p.Key,
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Data: data.Bytes(),
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}
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}
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func ProofDecoder(pop tmmerkle.ProofOp) (merkle.ProofOperator, error) {
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dec := gob.NewDecoder(bytes.NewBuffer(pop.Data))
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var proof ProofOp
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err := dec.Decode(&proof)
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if err != nil {
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return nil, err
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}
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return &proof, nil
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}
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func getHasher(hasher HasherType) hash.Hash {
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switch hasher {
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case SHA256:
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return sha256.New()
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default:
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return nil
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}
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}
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