forgejo/modules/git/object_format.go
Adam Majer d68a613ba8
Add support for sha256 repositories ()
Currently only SHA1 repositories are supported by Gitea. This adds
support for alternate SHA256 with the additional aim of easier support
for additional hash types in the future.

Fixes: 
Limited by: https://github.com/go-git/go-git/issues/899
Depend on: 

<img width="776" alt="图片" src="https://github.com/go-gitea/gitea/assets/81045/5448c9a7-608e-4341-a149-5dd0069c9447">

---------

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: 6543 <6543@obermui.de>
2024-01-19 17:05:02 +01:00

147 lines
3.9 KiB
Go

// Copyright 2023 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package git
import (
"crypto/sha1"
"crypto/sha256"
"regexp"
"strconv"
)
// sha1Pattern can be used to determine if a string is an valid sha
var sha1Pattern = regexp.MustCompile(`^[0-9a-f]{4,40}$`)
// sha256Pattern can be used to determine if a string is an valid sha
var sha256Pattern = regexp.MustCompile(`^[0-9a-f]{4,64}$`)
type ObjectFormat interface {
// Name returns the name of the object format
Name() string
// EmptyObjectID creates a new empty ObjectID from an object format hash name
EmptyObjectID() ObjectID
// EmptyTree is the hash of an empty tree
EmptyTree() ObjectID
// FullLength is the length of the hash's hex string
FullLength() int
// IsValid returns true if the input is a valid hash
IsValid(input string) bool
// MustID creates a new ObjectID from a byte slice
MustID(b []byte) ObjectID
// ComputeHash compute the hash for a given ObjectType and content
ComputeHash(t ObjectType, content []byte) ObjectID
}
/* SHA1 Type */
type Sha1ObjectFormatImpl struct{}
var (
emptySha1ObjectID = &Sha1Hash{}
emptySha1Tree = &Sha1Hash{
0x4b, 0x82, 0x5d, 0xc6, 0x42, 0xcb, 0x6e, 0xb9, 0xa0, 0x60,
0xe5, 0x4b, 0xf8, 0xd6, 0x92, 0x88, 0xfb, 0xee, 0x49, 0x04,
}
)
func (Sha1ObjectFormatImpl) Name() string { return "sha1" }
func (Sha1ObjectFormatImpl) EmptyObjectID() ObjectID {
return emptySha1ObjectID
}
func (Sha1ObjectFormatImpl) EmptyTree() ObjectID {
return emptySha1Tree
}
func (Sha1ObjectFormatImpl) FullLength() int { return 40 }
func (Sha1ObjectFormatImpl) IsValid(input string) bool {
return sha1Pattern.MatchString(input)
}
func (Sha1ObjectFormatImpl) MustID(b []byte) ObjectID {
var id Sha1Hash
copy(id[0:20], b)
return &id
}
// ComputeHash compute the hash for a given ObjectType and content
func (h Sha1ObjectFormatImpl) ComputeHash(t ObjectType, content []byte) ObjectID {
hasher := sha1.New()
_, _ = hasher.Write(t.Bytes())
_, _ = hasher.Write([]byte(" "))
_, _ = hasher.Write([]byte(strconv.FormatInt(int64(len(content)), 10)))
_, _ = hasher.Write([]byte{0})
// HashSum generates a SHA1 for the provided hash
var sha1 Sha1Hash
copy(sha1[:], hasher.Sum(nil))
return &sha1
}
/* SHA256 Type */
type Sha256ObjectFormatImpl struct{}
var (
emptySha256ObjectID = &Sha256Hash{}
emptySha256Tree = &Sha256Hash{
0x6e, 0xf1, 0x9b, 0x41, 0x22, 0x5c, 0x53, 0x69, 0xf1, 0xc1,
0x04, 0xd4, 0x5d, 0x8d, 0x85, 0xef, 0xa9, 0xb0, 0x57, 0xb5,
0x3b, 0x14, 0xb4, 0xb9, 0xb9, 0x39, 0xdd, 0x74, 0xde, 0xcc,
0x53, 0x21,
}
)
func (Sha256ObjectFormatImpl) Name() string { return "sha256" }
func (Sha256ObjectFormatImpl) EmptyObjectID() ObjectID {
return emptySha256ObjectID
}
func (Sha256ObjectFormatImpl) EmptyTree() ObjectID {
return emptySha256Tree
}
func (Sha256ObjectFormatImpl) FullLength() int { return 64 }
func (Sha256ObjectFormatImpl) IsValid(input string) bool {
return sha256Pattern.MatchString(input)
}
func (Sha256ObjectFormatImpl) MustID(b []byte) ObjectID {
var id Sha256Hash
copy(id[0:32], b)
return &id
}
// ComputeHash compute the hash for a given ObjectType and content
func (h Sha256ObjectFormatImpl) ComputeHash(t ObjectType, content []byte) ObjectID {
hasher := sha256.New()
_, _ = hasher.Write(t.Bytes())
_, _ = hasher.Write([]byte(" "))
_, _ = hasher.Write([]byte(strconv.FormatInt(int64(len(content)), 10)))
_, _ = hasher.Write([]byte{0})
// HashSum generates a SHA256 for the provided hash
var sha256 Sha1Hash
copy(sha256[:], hasher.Sum(nil))
return &sha256
}
var (
Sha1ObjectFormat ObjectFormat = Sha1ObjectFormatImpl{}
Sha256ObjectFormat ObjectFormat = Sha256ObjectFormatImpl{}
)
var SupportedObjectFormats = []ObjectFormat{
Sha1ObjectFormat,
}
func ObjectFormatFromName(name string) ObjectFormat {
for _, objectFormat := range SupportedObjectFormats {
if name == objectFormat.Name() {
return objectFormat
}
}
return nil
}
func IsValidObjectFormat(name string) bool {
return ObjectFormatFromName(name) != nil
}