func (a *AddrManager) getTriedBucket(netAddr *btcwire.NetAddress) int {
// bitcoind hashes this as:
// doublesha256(key + group + truncate_to_64bits(doublesha256(key)) % buckets_per_group) % num_buckets
data1 := []byte{}
data1 = append(data1, a.key[:]...)
data1 = append(data1, []byte(NetAddressKey(netAddr))...)
hash1 := btcwire.DoubleSha256(data1)
hash64 := binary.LittleEndian.Uint64(hash1)
hash64 %= triedBucketsPerGroup
var hashbuf [8]byte
binary.LittleEndian.PutUint64(hashbuf[:], hash64)
data2 := []byte{}
data2 = append(data2, a.key[:]...)
data2 = append(data2, GroupKey(netAddr)...)
data2 = append(data2, hashbuf[:]...)
hash2 := btcwire.DoubleSha256(data2)
return int(binary.LittleEndian.Uint64(hash2) % triedBucketCount)
}
func (a *AddrManager) getNewBucket(netAddr, srcAddr *btcwire.NetAddress) int {
// bitcoind:
// doublesha256(key + sourcegroup + int64(doublesha256(key + group + sourcegroup))%bucket_per_source_group) % num_new_buckets
data1 := []byte{}
data1 = append(data1, a.key[:]...)
data1 = append(data1, []byte(GroupKey(netAddr))...)
data1 = append(data1, []byte(GroupKey(srcAddr))...)
hash1 := btcwire.DoubleSha256(data1)
hash64 := binary.LittleEndian.Uint64(hash1)
hash64 %= newBucketsPerGroup
var hashbuf [8]byte
binary.LittleEndian.PutUint64(hashbuf[:], hash64)
data2 := []byte{}
data2 = append(data2, a.key[:]...)
data2 = append(data2, GroupKey(srcAddr)...)
data2 = append(data2, hashbuf[:]...)
hash2 := btcwire.DoubleSha256(data2)
return int(binary.LittleEndian.Uint64(hash2) % newBucketCount)
}
// HashMerkleBranches takes two hashes, treated as the left and right tree
// nodes, and returns the hash of their concatenation. This is a helper
// function used to aid in the generation of a merkle tree.
func HashMerkleBranches(left *btcwire.ShaHash, right *btcwire.ShaHash) *btcwire.ShaHash {
// Concatenate the left and right nodes.
var sha [btcwire.HashSize * 2]byte
copy(sha[:btcwire.HashSize], left.Bytes())
copy(sha[btcwire.HashSize:], right.Bytes())
// Create a new sha hash from the double sha 256. Ignore the error
// here since SetBytes can't fail here due to the fact DoubleSha256
// always returns a []byte of the right size regardless of input.
newSha, _ := btcwire.NewShaHash(btcwire.DoubleSha256(sha[:]))
return newSha
}