diff options
Diffstat (limited to 'pow/ethash.go')
| -rw-r--r-- | pow/ethash.go | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/pow/ethash.go b/pow/ethash.go index 602f9324f..9dfeedb78 100644 --- a/pow/ethash.go +++ b/pow/ethash.go @@ -35,6 +35,7 @@ import ( ) var ( + ErrNonceOutOfRange = errors.New("nonce out of range") ErrInvalidDifficulty = errors.New("non-positive difficulty") ErrInvalidMixDigest = errors.New("invalid mix digest") ErrInvalidPoW = errors.New("pow difficulty invalid") @@ -174,13 +175,18 @@ func NewSharedEthash() PoW { // Verify implements PoW, checking whether the given block satisfies the PoW // difficulty requirements. func (ethash *Ethash) Verify(block Block) error { + // Sanity check that the block number is below the lookup table size (60M blocks) + number := block.NumberU64() + if number/epochLength >= uint64(len(cacheSizes)) { + // Go < 1.7 cannot calculate new cache/dataset sizes (no fast prime check) + return ErrNonceOutOfRange + } // Ensure twe have a valid difficulty for the block difficulty := block.Difficulty() if difficulty.Sign() <= 0 { return ErrInvalidDifficulty } // Recompute the digest and PoW value and verify against the block - number := block.NumberU64() cache := ethash.cache(number) size := datasetSize(number) |