99 lines
2.7 KiB
Go
99 lines
2.7 KiB
Go
|
package hash
|
||
|
|
|
||
|
|
import (
|
||
|
|
"bytes"
|
||
|
|
|
||
|
|
"github.com/mr-tron/base58"
|
||
|
|
"github.com/nspcc-dev/neofs-proto/internal"
|
||
|
|
"github.com/nspcc-dev/tzhash/tz"
|
||
|
|
"github.com/pkg/errors"
|
||
|
|
)
|
||
|
|
|
||
|
|
// HomomorphicHashSize contains size of HH.
|
||
|
|
const HomomorphicHashSize = 64
|
||
|
|
|
||
|
|
// Hash is implementation of HomomorphicHash.
|
||
|
|
type Hash [HomomorphicHashSize]byte
|
||
|
|
|
||
|
|
// ErrWrongDataSize raised when wrong size of bytes is passed to unmarshal HH.
|
||
|
|
const ErrWrongDataSize = internal.Error("wrong data size")
|
||
|
|
|
||
|
|
var (
|
||
|
|
_ internal.Custom = (*Hash)(nil)
|
||
|
|
|
||
|
|
emptyHH [HomomorphicHashSize]byte
|
||
|
|
)
|
||
|
|
|
||
|
|
// Size returns size of Hash (HomomorphicHashSize).
|
||
|
|
func (h Hash) Size() int { return HomomorphicHashSize }
|
||
|
|
|
||
|
|
// Empty checks that Hash is empty.
|
||
|
|
func (h Hash) Empty() bool { return bytes.Equal(h.Bytes(), emptyHH[:]) }
|
||
|
|
|
||
|
|
// Reset sets current Hash to empty value.
|
||
|
|
func (h *Hash) Reset() { *h = Hash{} }
|
||
|
|
|
||
|
|
// ProtoMessage method to satisfy proto.Message interface.
|
||
|
|
func (h Hash) ProtoMessage() {}
|
||
|
|
|
||
|
|
// Bytes represents Hash as bytes.
|
||
|
|
func (h Hash) Bytes() []byte {
|
||
|
|
buf := make([]byte, HomomorphicHashSize)
|
||
|
|
copy(buf, h[:])
|
||
|
|
return h[:]
|
||
|
|
}
|
||
|
|
|
||
|
|
// Marshal returns bytes representation of Hash.
|
||
|
|
func (h Hash) Marshal() ([]byte, error) { return h.Bytes(), nil }
|
||
|
|
|
||
|
|
// MarshalTo tries to marshal Hash into passed bytes and returns count of copied bytes.
|
||
|
|
func (h *Hash) MarshalTo(data []byte) (int, error) { return copy(data, h.Bytes()), nil }
|
||
|
|
|
||
|
|
// Unmarshal tries to parse bytes into valid Hash.
|
||
|
|
func (h *Hash) Unmarshal(data []byte) error {
|
||
|
|
if ln := len(data); ln != HomomorphicHashSize {
|
||
|
|
return errors.Wrapf(ErrWrongDataSize, "expect=%d, actual=%d", HomomorphicHashSize, ln)
|
||
|
|
}
|
||
|
|
|
||
|
|
copy((*h)[:], data)
|
||
|
|
return nil
|
||
|
|
}
|
||
|
|
|
||
|
|
// String returns string representation of Hash.
|
||
|
|
func (h Hash) String() string { return base58.Encode(h[:]) }
|
||
|
|
|
||
|
|
// Equal checks that current Hash is equal to passed Hash.
|
||
|
|
func (h Hash) Equal(hash Hash) bool { return h == hash }
|
||
|
|
|
||
|
|
// Verify validates if current hash generated from passed data.
|
||
|
|
func (h Hash) Verify(data []byte) bool { return h.Equal(Sum(data)) }
|
||
|
|
|
||
|
|
// Validate checks if combined hashes are equal to current Hash.
|
||
|
|
func (h Hash) Validate(hashes []Hash) bool {
|
||
|
|
var hashBytes = make([][]byte, 0, len(hashes))
|
||
|
|
for i := range hashes {
|
||
|
|
hashBytes = append(hashBytes, hashes[i].Bytes())
|
||
|
|
}
|
||
|
|
ok, err := tz.Validate(h.Bytes(), hashBytes)
|
||
|
|
return err == nil && ok
|
||
|
|
}
|
||
|
|
|
||
|
|
// Sum returns Tillich-Zémor checksum of data.
|
||
|
|
func Sum(data []byte) Hash { return tz.Sum(data) }
|
||
|
|
|
||
|
|
// Concat combines hashes based on homomorphic property.
|
||
|
|
func Concat(hashes []Hash) (Hash, error) {
|
||
|
|
var (
|
||
|
|
hash Hash
|
||
|
|
h = make([][]byte, 0, len(hashes))
|
||
|
|
)
|
||
|
|
for i := range hashes {
|
||
|
|
h = append(h, hashes[i].Bytes())
|
||
|
|
}
|
||
|
|
cat, err := tz.Concat(h)
|
||
|
|
if err != nil {
|
||
|
|
return hash, err
|
||
|
|
}
|
||
|
|
return hash, hash.Unmarshal(cat)
|
||
|
|
}
|