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package merkle
// Copyright 2016 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// These tests were taken from https://github.com/google/trillian/blob/master/merkle/rfc6962/rfc6962_test.go,
// and consequently fall under the above license.
import (
"bytes"
"encoding/hex"
"testing"
"github.com/tendermint/tendermint/crypto/tmhash"
)
func TestRFC6962Hasher(t *testing.T) {
_, leafHashTrail := trailsFromByteSlices([][]byte{[]byte("L123456")})
leafHash := leafHashTrail.Hash
_, leafHashTrail = trailsFromByteSlices([][]byte{{}})
emptyLeafHash := leafHashTrail.Hash
for _, tc := range []struct {
desc string
got []byte
want string
}{
// Since creating a merkle tree of no leaves is unsupported here, we skip
// the corresponding trillian test vector.
// Check that the empty hash is not the same as the hash of an empty leaf.
// echo -n 00 | xxd -r -p | sha256sum
{
desc: "RFC6962 Empty Leaf",
want: "6e340b9cffb37a989ca544e6bb780a2c78901d3fb33738768511a30617afa01d"[:tmhash.Size*2],
got: emptyLeafHash,
},
// echo -n 004C313233343536 | xxd -r -p | sha256sum
{
desc: "RFC6962 Leaf",
want: "395aa064aa4c29f7010acfe3f25db9485bbd4b91897b6ad7ad547639252b4d56"[:tmhash.Size*2],
got: leafHash,
},
// echo -n 014E3132334E343536 | xxd -r -p | sha256sum
{
desc: "RFC6962 Node",
want: "aa217fe888e47007fa15edab33c2b492a722cb106c64667fc2b044444de66bbb"[:tmhash.Size*2],
got: innerHash([]byte("N123"), []byte("N456")),
},
} {
t.Run(tc.desc, func(t *testing.T) {
wantBytes, err := hex.DecodeString(tc.want)
if err != nil {
t.Fatalf("hex.DecodeString(%x): %v", tc.want, err)
}
if got, want := tc.got, wantBytes; !bytes.Equal(got, want) {
t.Errorf("got %x, want %x", got, want)
}
})
}
}
func TestRFC6962HasherCollisions(t *testing.T) {
// Check that different leaves have different hashes.
leaf1, leaf2 := []byte("Hello"), []byte("World")
_, leafHashTrail := trailsFromByteSlices([][]byte{leaf1})
hash1 := leafHashTrail.Hash
_, leafHashTrail = trailsFromByteSlices([][]byte{leaf2})
hash2 := leafHashTrail.Hash
if bytes.Equal(hash1, hash2) {
t.Errorf("Leaf hashes should differ, but both are %x", hash1)
}
// Compute an intermediate subtree hash.
_, subHash1Trail := trailsFromByteSlices([][]byte{hash1, hash2})
subHash1 := subHash1Trail.Hash
// Check that this is not the same as a leaf hash of their concatenation.
preimage := append(hash1, hash2...)
_, forgedHashTrail := trailsFromByteSlices([][]byte{preimage})
forgedHash := forgedHashTrail.Hash
if bytes.Equal(subHash1, forgedHash) {
t.Errorf("Hasher is not second-preimage resistant")
}
// Swap the order of nodes and check that the hash is different.
_, subHash2Trail := trailsFromByteSlices([][]byte{hash2, hash1})
subHash2 := subHash2Trail.Hash
if bytes.Equal(subHash1, subHash2) {
t.Errorf("Subtree hash does not depend on the order of leaves")
}
}