githaven/modules/packages/multi_hasher.go
flynnnnnnnnnn e81ccc406b
Implement FSFE REUSE for golang files (#21840)
Change all license headers to comply with REUSE specification.

Fix #16132

Co-authored-by: flynnnnnnnnnn <flynnnnnnnnnn@github>
Co-authored-by: John Olheiser <john.olheiser@gmail.com>
2022-11-27 18:20:29 +00:00

123 lines
2.9 KiB
Go

// Copyright 2022 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package packages
import (
"crypto/md5"
"crypto/sha1"
"crypto/sha256"
"crypto/sha512"
"encoding"
"errors"
"hash"
"io"
)
const (
marshaledSizeMD5 = 92
marshaledSizeSHA1 = 96
marshaledSizeSHA256 = 108
marshaledSizeSHA512 = 204
marshaledSize = marshaledSizeMD5 + marshaledSizeSHA1 + marshaledSizeSHA256 + marshaledSizeSHA512
)
// HashSummer provide a Sums method
type HashSummer interface {
Sums() (hashMD5, hashSHA1, hashSHA256, hashSHA512 []byte)
}
// MultiHasher calculates multiple checksums
type MultiHasher struct {
md5 hash.Hash
sha1 hash.Hash
sha256 hash.Hash
sha512 hash.Hash
combinedWriter io.Writer
}
// NewMultiHasher creates a multi hasher
func NewMultiHasher() *MultiHasher {
md5 := md5.New()
sha1 := sha1.New()
sha256 := sha256.New()
sha512 := sha512.New()
combinedWriter := io.MultiWriter(md5, sha1, sha256, sha512)
return &MultiHasher{
md5,
sha1,
sha256,
sha512,
combinedWriter,
}
}
// MarshalBinary implements encoding.BinaryMarshaler
func (h *MultiHasher) MarshalBinary() ([]byte, error) {
md5Bytes, err := h.md5.(encoding.BinaryMarshaler).MarshalBinary()
if err != nil {
return nil, err
}
sha1Bytes, err := h.sha1.(encoding.BinaryMarshaler).MarshalBinary()
if err != nil {
return nil, err
}
sha256Bytes, err := h.sha256.(encoding.BinaryMarshaler).MarshalBinary()
if err != nil {
return nil, err
}
sha512Bytes, err := h.sha512.(encoding.BinaryMarshaler).MarshalBinary()
if err != nil {
return nil, err
}
b := make([]byte, 0, marshaledSize)
b = append(b, md5Bytes...)
b = append(b, sha1Bytes...)
b = append(b, sha256Bytes...)
b = append(b, sha512Bytes...)
return b, nil
}
// UnmarshalBinary implements encoding.BinaryUnmarshaler
func (h *MultiHasher) UnmarshalBinary(b []byte) error {
if len(b) != marshaledSize {
return errors.New("invalid hash state size")
}
if err := h.md5.(encoding.BinaryUnmarshaler).UnmarshalBinary(b[:marshaledSizeMD5]); err != nil {
return err
}
b = b[marshaledSizeMD5:]
if err := h.sha1.(encoding.BinaryUnmarshaler).UnmarshalBinary(b[:marshaledSizeSHA1]); err != nil {
return err
}
b = b[marshaledSizeSHA1:]
if err := h.sha256.(encoding.BinaryUnmarshaler).UnmarshalBinary(b[:marshaledSizeSHA256]); err != nil {
return err
}
b = b[marshaledSizeSHA256:]
return h.sha512.(encoding.BinaryUnmarshaler).UnmarshalBinary(b[:marshaledSizeSHA512])
}
// Write implements io.Writer
func (h *MultiHasher) Write(p []byte) (int, error) {
return h.combinedWriter.Write(p)
}
// Sums gets the MD5, SHA1, SHA256 and SHA512 checksums of the data
func (h *MultiHasher) Sums() (hashMD5, hashSHA1, hashSHA256, hashSHA512 []byte) {
hashMD5 = h.md5.Sum(nil)
hashSHA1 = h.sha1.Sum(nil)
hashSHA256 = h.sha256.Sum(nil)
hashSHA512 = h.sha512.Sum(nil)
return hashMD5, hashSHA1, hashSHA256, hashSHA512
}