From 8363aba7acaab4379a3461cfc3b7b35e8436693f Mon Sep 17 00:00:00 2001
From: Gustav Simonsson <gustav.simonsson@gmail.com>
Date: Wed, 24 Jun 2015 07:17:21 +0200
Subject: Update Ethash Godeps
---
Godeps/Godeps.json | 4 ++--
.../src/github.com/ethereum/ethash/ethash.go | 28 +++++++++++++++-------
.../src/github.com/ethereum/ethash/ethash_test.go | 16 +++++++++++++
.../ethereum/ethash/src/libethash/internal.c | 4 ++--
.../ethereum/ethash/src/libethash/internal.h | 21 +++++++++++-----
5 files changed, 54 insertions(+), 19 deletions(-)
diff --git a/Godeps/Godeps.json b/Godeps/Godeps.json
index 0607990a8..6d68c18ec 100644
--- a/Godeps/Godeps.json
+++ b/Godeps/Godeps.json
@@ -21,8 +21,8 @@
},
{
"ImportPath": "github.com/ethereum/ethash",
- "Comment": "v23.1-222-g173b8ff",
- "Rev": "173b8ff953610c13710061e83b95b50c73d7ea50"
+ "Comment": "v23.1-227-g8f6ccaa",
+ "Rev": "8f6ccaaef9b418553807a73a95cb5f49cd3ea39f"
},
{
"ImportPath": "github.com/howeyc/fsnotify",
diff --git a/Godeps/_workspace/src/github.com/ethereum/ethash/ethash.go b/Godeps/_workspace/src/github.com/ethereum/ethash/ethash.go
index 73c5bf664..d0864da7f 100644
--- a/Godeps/_workspace/src/github.com/ethereum/ethash/ethash.go
+++ b/Godeps/_workspace/src/github.com/ethereum/ethash/ethash.go
@@ -100,19 +100,29 @@ type Light struct {
func (l *Light) Verify(block pow.Block) bool {
// TODO: do ethash_quick_verify before getCache in order
// to prevent DOS attacks.
- var (
- blockNum = block.NumberU64()
- difficulty = block.Difficulty()
- cache = l.getCache(blockNum)
- dagSize = C.ethash_get_datasize(C.uint64_t(blockNum))
- )
- if l.test {
- dagSize = dagSizeForTesting
- }
+ blockNum := block.NumberU64()
if blockNum >= epochLength*2048 {
glog.V(logger.Debug).Infof("block number %d too high, limit is %d", epochLength*2048)
return false
}
+
+ difficulty := block.Difficulty()
+ /* Cannot happen if block header diff is validated prior to PoW, but can
+ happen if PoW is checked first due to parallel PoW checking.
+ We could check the minimum valid difficulty but for SoC we avoid (duplicating)
+ Ethereum protocol consensus rules here which are not in scope of Ethash
+ */
+ if difficulty.Cmp(common.Big0) == 0 {
+ glog.V(logger.Debug).Infof("invalid block difficulty")
+ return false
+ }
+
+ cache := l.getCache(blockNum)
+ dagSize := C.ethash_get_datasize(C.uint64_t(blockNum))
+
+ if l.test {
+ dagSize = dagSizeForTesting
+ }
// Recompute the hash using the cache.
hash := hashToH256(block.HashNoNonce())
ret := C.ethash_light_compute_internal(cache.ptr, dagSize, hash, C.uint64_t(block.Nonce()))
diff --git a/Godeps/_workspace/src/github.com/ethereum/ethash/ethash_test.go b/Godeps/_workspace/src/github.com/ethereum/ethash/ethash_test.go
index e6833e343..1e1de989d 100644
--- a/Godeps/_workspace/src/github.com/ethereum/ethash/ethash_test.go
+++ b/Godeps/_workspace/src/github.com/ethereum/ethash/ethash_test.go
@@ -11,6 +11,7 @@ import (
"testing"
"github.com/ethereum/go-ethereum/common"
+ "github.com/ethereum/go-ethereum/crypto"
)
func init() {
@@ -59,6 +60,14 @@ var validBlocks = []*testBlock{
},
}
+var invalidZeroDiffBlock = testBlock{
+ number: 61440000,
+ hashNoNonce: crypto.Sha3Hash([]byte("foo")),
+ difficulty: big.NewInt(0),
+ nonce: 0xcafebabec00000fe,
+ mixDigest: crypto.Sha3Hash([]byte("bar")),
+}
+
func TestEthashVerifyValid(t *testing.T) {
eth := New()
for i, block := range validBlocks {
@@ -68,6 +77,13 @@ func TestEthashVerifyValid(t *testing.T) {
}
}
+func TestEthashVerifyInvalid(t *testing.T) {
+ eth := New()
+ if eth.Verify(&invalidZeroDiffBlock) {
+ t.Errorf("should not validate - we just ensure it does not panic on this block")
+ }
+}
+
func TestEthashConcurrentVerify(t *testing.T) {
eth, err := NewForTesting()
if err != nil {
diff --git a/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/internal.c b/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/internal.c
index b28a59e43..338aa5ecd 100644
--- a/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/internal.c
+++ b/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/internal.c
@@ -284,13 +284,13 @@ bool ethash_quick_check_difficulty(
ethash_h256_t const* header_hash,
uint64_t const nonce,
ethash_h256_t const* mix_hash,
- ethash_h256_t const* difficulty
+ ethash_h256_t const* boundary
)
{
ethash_h256_t return_hash;
ethash_quick_hash(&return_hash, header_hash, nonce, mix_hash);
- return ethash_check_difficulty(&return_hash, difficulty);
+ return ethash_check_difficulty(&return_hash, boundary);
}
ethash_light_t ethash_light_new_internal(uint64_t cache_size, ethash_h256_t const* seed)
diff --git a/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/internal.h b/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/internal.h
index 4e2b695ac..26c395ad6 100644
--- a/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/internal.h
+++ b/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/internal.h
@@ -46,27 +46,36 @@ static inline void ethash_h256_reset(ethash_h256_t* hash)
memset(hash, 0, 32);
}
-// Returns if hash is less than or equal to difficulty
+// Returns if hash is less than or equal to boundary (2^256/difficulty)
static inline bool ethash_check_difficulty(
ethash_h256_t const* hash,
- ethash_h256_t const* difficulty
+ ethash_h256_t const* boundary
)
{
- // Difficulty is big endian
+ // Boundary is big endian
for (int i = 0; i < 32; i++) {
- if (ethash_h256_get(hash, i) == ethash_h256_get(difficulty, i)) {
+ if (ethash_h256_get(hash, i) == ethash_h256_get(boundary, i)) {
continue;
}
- return ethash_h256_get(hash, i) < ethash_h256_get(difficulty, i);
+ return ethash_h256_get(hash, i) < ethash_h256_get(boundary, i);
}
return true;
}
+/**
+ * Difficulty quick check for POW preverification
+ *
+ * @param header_hash The hash of the header
+ * @param nonce The block's nonce
+ * @param mix_hash The mix digest hash
+ * @param boundary The boundary is defined as (2^256 / difficulty)
+ * @return true for succesful pre-verification and false otherwise
+ */
bool ethash_quick_check_difficulty(
ethash_h256_t const* header_hash,
uint64_t const nonce,
ethash_h256_t const* mix_hash,
- ethash_h256_t const* difficulty
+ ethash_h256_t const* boundary
);
struct ethash_light {
--
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