first commit

crypto/merkle/compile.sh

@@ -0,0 +1,6 @@
+#! /bin/bash
+
+protoc --gogo_out=. -I $GOPATH/src/ -I . -I $GOPATH/src/github.com/gogo/protobuf/protobuf merkle.proto
+echo "--> adding nolint declarations to protobuf generated files"
+awk '/package merkle/ { print "//nolint: gas"; print; next }1' merkle.pb.go > merkle.pb.go.new
+mv merkle.pb.go.new merkle.pb.go

crypto/merkle/merkle.pb.go

@@ -0,0 +1,101 @@
+// Code generated by protoc-gen-gogo. DO NOT EDIT.
+// source: merkle.proto
+
+/*
+Package merkle is a generated protocol buffer package.
+
+It is generated from these files:
+	merkle.proto
+
+It has these top-level messages:
+	ProofOp
+	Proof
+*/
+//nolint: gas
+package merkle
+
+import proto "github.com/gogo/protobuf/proto"
+import fmt "fmt"
+import math "math"
+import _ "github.com/gogo/protobuf/gogoproto"
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ = proto.Marshal
+var _ = fmt.Errorf
+var _ = math.Inf
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the proto package it is being compiled against.
+// A compilation error at this line likely means your copy of the
+// proto package needs to be updated.
+const _ = proto.GoGoProtoPackageIsVersion2 // please upgrade the proto package
+
+type ProofOp struct {
+	Type string `protobuf:"bytes,1,opt,name=type,proto3" json:"type,omitempty"`
+	Key  string `protobuf:"bytes,2,opt,name=key,proto3" json:"key,omitempty"`
+	Data []byte `protobuf:"bytes,3,opt,name=data,proto3" json:"data,omitempty"`
+}
+
+func (m *ProofOp) Reset()                    { *m = ProofOp{} }
+func (m *ProofOp) String() string            { return proto.CompactTextString(m) }
+func (*ProofOp) ProtoMessage()               {}
+func (*ProofOp) Descriptor() ([]byte, []int) { return fileDescriptorMerkle, []int{0} }
+
+func (m *ProofOp) GetType() string {
+	if m != nil {
+		return m.Type
+	}
+	return ""
+}
+
+func (m *ProofOp) GetKey() string {
+	if m != nil {
+		return m.Key
+	}
+	return ""
+}
+
+func (m *ProofOp) GetData() []byte {
+	if m != nil {
+		return m.Data
+	}
+	return nil
+}
+
+type Proof struct {
+	Ops []ProofOp `protobuf:"bytes,1,rep,name=ops" json:"ops"`
+}
+
+func (m *Proof) Reset()                    { *m = Proof{} }
+func (m *Proof) String() string            { return proto.CompactTextString(m) }
+func (*Proof) ProtoMessage()               {}
+func (*Proof) Descriptor() ([]byte, []int) { return fileDescriptorMerkle, []int{1} }
+
+func (m *Proof) GetOps() []ProofOp {
+	if m != nil {
+		return m.Ops
+	}
+	return nil
+}
+
+func init() {
+	proto.RegisterType((*ProofOp)(nil), "merkle.ProofOp")
+	proto.RegisterType((*Proof)(nil), "merkle.Proof")
+}
+
+func init() { proto.RegisterFile("merkle.proto", fileDescriptorMerkle) }
+
+var fileDescriptorMerkle = []byte{
+	// 168 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xe2, 0xe2, 0xc9, 0x4d, 0x2d, 0xca,
+	0xce, 0x49, 0xd5, 0x2b, 0x28, 0xca, 0x2f, 0xc9, 0x17, 0x62, 0x83, 0xf0, 0xa4, 0x74, 0xd3, 0x33,
+	0x4b, 0x32, 0x4a, 0x93, 0xf4, 0x92, 0xf3, 0x73, 0xf5, 0xd3, 0xf3, 0xd3, 0xf3, 0xf5, 0xc1, 0xd2,
+	0x49, 0xa5, 0x69, 0x60, 0x1e, 0x98, 0x03, 0x66, 0x41, 0xb4, 0x29, 0x39, 0x73, 0xb1, 0x07, 0x14,
+	0xe5, 0xe7, 0xa7, 0xf9, 0x17, 0x08, 0x09, 0x71, 0xb1, 0x94, 0x54, 0x16, 0xa4, 0x4a, 0x30, 0x2a,
+	0x30, 0x6a, 0x70, 0x06, 0x81, 0xd9, 0x42, 0x02, 0x5c, 0xcc, 0xd9, 0xa9, 0x95, 0x12, 0x4c, 0x60,
+	0x21, 0x10, 0x13, 0xa4, 0x2a, 0x25, 0xb1, 0x24, 0x51, 0x82, 0x59, 0x81, 0x51, 0x83, 0x27, 0x08,
+	0xcc, 0x56, 0x32, 0xe0, 0x62, 0x05, 0x1b, 0x22, 0xa4, 0xce, 0xc5, 0x9c, 0x5f, 0x50, 0x2c, 0xc1,
+	0xa8, 0xc0, 0xac, 0xc1, 0x6d, 0xc4, 0xaf, 0x07, 0x75, 0x20, 0xd4, 0x02, 0x27, 0x96, 0x13, 0xf7,
+	0xe4, 0x19, 0x82, 0x40, 0x2a, 0x92, 0xd8, 0xc0, 0xb6, 0x1b, 0x03, 0x02, 0x00, 0x00, 0xff, 0xff,
+	0x52, 0x58, 0x00, 0xa7, 0xc4, 0x00, 0x00, 0x00,
+}

crypto/merkle/merkle.proto

@@ -0,0 +1,19 @@
+syntax = "proto3";
+package merkle;
+
+// For more information on gogo.proto, see:
+// https://github.com/gogo/protobuf/blob/master/extensions.md
+import "github.com/gogo/protobuf/gogoproto/gogo.proto";
+
+//----------------------------------------
+// Message types
+
+message ProofOp {
+  string type = 1;
+  string key = 2;
+  bytes data = 3;
+}
+
+message Proof {
+  repeated ProofOp ops = 1 [(gogoproto.nullable)=false];
+}

crypto/merkle/proof.go

@@ -0,0 +1,140 @@
+package merkle
+
+import (
+	"bytes"
+	"reflect"
+
+	"github.com/tendermint/go-amino"
+	cmn "github.com/tendermint/tmlibs/common"
+)
+
+//----------------------------------------
+// Extension of ProofOp (defined in merkle.proto)
+
+func (po ProofOp) Bytes() []byte {
+	bz, err := amino.MarshalBinary(po)
+	if err != nil {
+		panic(err)
+	}
+	return bz
+}
+
+//----------------------------------------
+// ProofOp gets converted to an instance of ProofOperator:
+
+type ProofOperator interface {
+	Run([][]byte) ([][]byte, error)
+	GetKey() string
+	ProofOp() ProofOp
+}
+
+//----------------------------------------
+// Operations on a list of ProofOperators
+
+type ProofOperators []ProofOperator
+
+func (poz ProofOperators) VerifyValue(root []byte, value []byte, keys ...string) (err error) {
+	return poz.Verify(root, [][]byte{value}, keys...)
+}
+
+func (poz ProofOperators) Verify(root []byte, args [][]byte, keys ...string) (err error) {
+	for i, op := range poz {
+		key := op.GetKey()
+		if key != "" {
+			if keys[0] != key {
+				return cmn.NewError("Key mismatch on operation #%d: expected %+v but %+v", i, []byte(keys[0]), []byte(key))
+			}
+			keys = keys[1:]
+		}
+		args, err = op.Run(args)
+		if err != nil {
+			return
+		}
+	}
+	if !bytes.Equal(root, args[0]) {
+		return cmn.NewError("Calculated root hash is invalid: expected %+v but %+v", root, args[0])
+	}
+	return nil
+}
+
+//----------------------------------------
+// ProofRuntime - main entrypoint
+
+type OpDecoder func(ProofOp) (ProofOperator, error)
+
+type ProofRuntime struct {
+	decoders map[string]OpDecoder
+}
+
+func NewProofRuntime() *ProofRuntime {
+	return &ProofRuntime{
+		decoders: make(map[string]OpDecoder),
+	}
+}
+
+func (prt *ProofRuntime) RegisterAminoOpDecoder(typ string, opType reflect.Type) {
+	prt.RegisterOpDecoder(
+		typ,
+		func(pop ProofOp) (ProofOperator, error) {
+			newOp := reflect.New(opType).Elem().Interface()
+			err := cdc.UnmarshalBinary(pop.Data, &newOp)
+			if err != nil {
+				return nil, cmn.ErrorWrap(err, "decoding ProofOp.Data")
+			}
+			return newOp.(ProofOperator), nil
+		},
+	)
+}
+
+func (prt *ProofRuntime) RegisterOpDecoder(typ string, dec OpDecoder) {
+	_, ok := prt.decoders[typ]
+	if ok {
+		panic("already registered for type " + typ)
+	}
+	prt.decoders[typ] = dec
+}
+
+func (prt *ProofRuntime) Decode(pop ProofOp) (ProofOperator, error) {
+	decoder := prt.decoders[pop.Type]
+	if decoder == nil {
+		return nil, cmn.NewError("unrecognized proof type %v", pop.Type)
+	}
+	return decoder(pop)
+}
+
+func (prt *ProofRuntime) DecodeProof(proof *Proof) (poz ProofOperators, err error) {
+	poz = ProofOperators(nil)
+	for _, pop := range proof.Ops {
+		operator, err := prt.Decode(pop)
+		if err != nil {
+			return nil, cmn.ErrorWrap(err, "decoding a proof operator")
+		}
+		poz = append(poz, operator)
+	}
+	return
+}
+
+func (prt *ProofRuntime) VerifyValue(proof *Proof, root []byte, value []byte, keys ...string) (err error) {
+	return prt.Verify(proof, root, [][]byte{value}, keys...)
+}
+
+func (prt *ProofRuntime) Verify(proof *Proof, root []byte, args [][]byte, keys ...string) (err error) {
+	poz, err := prt.DecodeProof(proof)
+	if err != nil {
+		return cmn.ErrorWrap(err, "decoding proof")
+	}
+	return poz.Verify(root, args, keys...)
+}
+
+// DefaultProofRuntime only knows about Simple value
+// proofs.
+// To use e.g. IAVL proofs, register op-decoders as
+// defined in the IAVL package.
+func DefaultProofRuntime() (prt *ProofRuntime) {
+	prt = NewProofRuntime()
+	prt.RegisterAminoOpDecoder(
+		ProofOpSimpleValue,
+		reflect.TypeOf(SimpleValueOp{}),
+	)
+	return
+}

crypto/merkle/proof_simple_value.go

@@ -0,0 +1,79 @@
+package merkle
+
+import (
+	"bytes"
+	"fmt"
+
+	"github.com/tendermint/tendermint/crypto/tmhash"
+	cmn "github.com/tendermint/tmlibs/common"
+)
+
+const ProofOpSimpleValue = "simple:v"
+
+// SimpleValueOp takes a key and a single value as argument and
+// produces the root hash.  The corresponding tree structure is
+// the SimpleMap tree.  SimpleMap takes a Hasher, and currently
+// Tendermint uses aminoHasher.  SimpleValueOp should support
+// the hash function as used in aminoHasher.  TODO support
+// additional hash functions here as options/args to this
+// operator.
+//
+// If the produced root hash matches the expected hash, the
+// proof is good.
+type SimpleValueOp struct {
+	// encoded in ProofOp.Key, not .Data
+	key string
+
+	// To encode in ProofOp.Data
+	Proof *SimpleProof `json:"simple-proof"`
+}
+
+var _ ProofOperator = SimpleValueOp{}
+
+func NewSimpleValueOp(key string, proof *SimpleProof) SimpleValueOp {
+	return SimpleValueOp{
+		key:   key,
+		Proof: proof,
+	}
+}
+
+func (op SimpleValueOp) String() string {
+	return fmt.Sprintf("SimpleValueOp{%v}", op.GetKey())
+}
+
+func (op SimpleValueOp) Run(args [][]byte) ([][]byte, error) {
+	if len(args) != 1 {
+		return nil, cmn.NewError("expected 1 arg, got %v", len(args))
+	}
+	value := args[0]
+	hasher := tmhash.New()
+	hasher.Write(value) // does not error
+	vhash := hasher.Sum(nil)
+
+	// Wrap <op.key, vhash> to hash the KVPair.
+	hasher = tmhash.New()
+	encodeByteSlice(hasher, []byte(op.key)) // does not error
+	encodeByteSlice(hasher, []byte(vhash))  // does not error
+	kvhash := hasher.Sum(nil)
+
+	if !bytes.Equal(kvhash, op.Proof.LeafHash) {
+		return nil, cmn.NewError("leaf hash mismatch: want %X got %X", op.Proof.LeafHash, kvhash)
+	}
+
+	return [][]byte{
+		op.Proof.ComputeRootHash(),
+	}, nil
+}
+
+func (op SimpleValueOp) GetKey() string {
+	return op.key
+}
+
+func (op SimpleValueOp) ProofOp() ProofOp {
+	bz := cdc.MustMarshalBinary(op)
+	return ProofOp{
+		Type: ProofOpSimpleValue,
+		Key:  op.key,
+		Data: bz,
+	}
+}

crypto/merkle/simple_proof.go

@@ -3,11 +3,22 @@ package merkle
 import (
 	"bytes"
 	"fmt"
+
+	cmn "github.com/tendermint/tmlibs/common"
 )
 
-// SimpleProof represents a simple merkle proof.
+// SimpleProof represents a simple Merkle proof.
+// NOTE: The convention for proofs is to include leaf hashes but to
+// exclude the root hash.
+// This convention is implemented across IAVL range proofs as well.
+// Keep this consistent unless there's a very good reason to change
+// everything.  This also affects the generalized proof system as
+// well.
 type SimpleProof struct {
-	Aunts [][]byte `json:"aunts"` // Hashes from leaf's sibling to a root's child.
+	Total    int      `json:"total"`     // Total number of items.
+	Index    int      `json:"index"`     // Index of item to prove.
+	LeafHash []byte   `json:"leaf_hash"` // Hash of item value.
+	Aunts    [][]byte `json:"aunts"`     // Hashes from leaf's sibling to a root's child.
 }
 
 // SimpleProofsFromHashers computes inclusion proof for given items.
@@ -18,7 +29,10 @@ func SimpleProofsFromHashers(items []Hasher) (rootHash []byte, proofs []*SimpleP
 	proofs = make([]*SimpleProof, len(items))
 	for i, trail := range trails {
 		proofs[i] = &SimpleProof{
-			Aunts: trail.FlattenAunts(),
+			Total:    len(items),
+			Index:    i,
+			LeafHash: trail.Hash,
+			Aunts:    trail.FlattenAunts(),
 		}
 	}
 	return
@@ -49,11 +63,32 @@ func SimpleProofsFromMap(m map[string]Hasher) (rootHash []byte, proofs map[strin
 	return
 }
 
-// Verify that leafHash is a leaf hash of the simple-merkle-tree
-// which hashes to rootHash.
-func (sp *SimpleProof) Verify(index int, total int, leafHash []byte, rootHash []byte) bool {
-	computedHash := computeHashFromAunts(index, total, leafHash, sp.Aunts)
-	return computedHash != nil && bytes.Equal(computedHash, rootHash)
+// Verify that the SimpleProof proves the root hash.
+func (sp *SimpleProof) Verify(rootHash []byte, index int, total int, leafHash []byte) error {
+	if sp.Index != index {
+		return cmn.NewError("invalid index: wanted %v got %v", index, sp.Index)
+	}
+	if sp.Total != total {
+		return cmn.NewError("invalid total: wanted %v got %v", total, sp.Total)
+	}
+	if !bytes.Equal(sp.LeafHash, leafHash) {
+		return cmn.NewError("invalid leaf hash: wanted %X got %X", leafHash, sp.LeafHash)
+	}
+	computedHash := sp.ComputeRootHash()
+	if !bytes.Equal(computedHash, rootHash) {
+		return cmn.NewError("invalid root hash: wanted %X got %X", rootHash, computedHash)
+	}
+	return nil
+}
+
+// Compute the root hash given a leaf hash.  Does not verify the result.
+func (sp *SimpleProof) ComputeRootHash() []byte {
+	return computeHashFromAunts(
+		sp.Index,
+		sp.Total,
+		sp.LeafHash,
+		sp.Aunts,
+	)
 }
 
 // String implements the stringer interface for SimpleProof.

crypto/merkle/wire.go

@@ -0,0 +1,16 @@
+package merkle
+
+import (
+	"github.com/tendermint/go-amino"
+)
+
+var cdc *amino.Codec
+
+func init() {
+	cdc = amino.NewCodec()
+	RegisterWire(cdc)
+}
+
+func RegisterWire(cdc *amino.Codec) {
+	// Nothing to do.
+}