Add support for sha256 repositories (#23894)

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: #13794
Limited by: https://github.com/go-git/go-git/issues/899
Depend on: #28138

<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>

models/git/commit_status.go

@@ -37,7 +37,7 @@ type CommitStatus struct {
 	SHA         string                 `xorm:"VARCHAR(64) NOT NULL INDEX UNIQUE(repo_sha_index)"`
 	TargetURL   string                 `xorm:"TEXT"`
 	Description string                 `xorm:"TEXT"`
-	ContextHash string                 `xorm:"char(40) index"`
+	ContextHash string                 `xorm:"VARCHAR(64) index"`
 	Context     string                 `xorm:"TEXT"`
 	Creator     *user_model.User       `xorm:"-"`
 	CreatorID   int64

models/issues/comment.go

@@ -270,7 +270,7 @@ type Comment struct {
 	UpdatedUnix timeutil.TimeStamp `xorm:"INDEX updated"`
 
 	// Reference issue in commit message
-	CommitSHA string `xorm:"VARCHAR(40)"`
+	CommitSHA string `xorm:"VARCHAR(64)"`
 
 	Attachments []*repo_model.Attachment `xorm:"-"`
 	Reactions   ReactionList             `xorm:"-"`

models/issues/pull.go

@@ -171,11 +171,11 @@ type PullRequest struct {
 	HeadBranch          string
 	HeadCommitID        string `xorm:"-"`
 	BaseBranch          string
-	MergeBase           string `xorm:"VARCHAR(40)"`
+	MergeBase           string `xorm:"VARCHAR(64)"`
 	AllowMaintainerEdit bool   `xorm:"NOT NULL DEFAULT false"`
 
 	HasMerged      bool               `xorm:"INDEX"`
-	MergedCommitID string             `xorm:"VARCHAR(40)"`
+	MergedCommitID string             `xorm:"VARCHAR(64)"`
 	MergerID       int64              `xorm:"INDEX"`
 	Merger         *user_model.User   `xorm:"-"`
 	MergedUnix     timeutil.TimeStamp `xorm:"updated INDEX"`

models/issues/review.go

@@ -116,7 +116,7 @@ type Review struct {
 	Content          string `xorm:"TEXT"`
 	// Official is a review made by an assigned approver (counts towards approval)
 	Official  bool   `xorm:"NOT NULL DEFAULT false"`
-	CommitID  string `xorm:"VARCHAR(40)"`
+	CommitID  string `xorm:"VARCHAR(64)"`
 	Stale     bool   `xorm:"NOT NULL DEFAULT false"`
 	Dismissed bool   `xorm:"NOT NULL DEFAULT false"`
 

models/migrations/fixtures/Test_RepositoryFormat/repository.yml

@@ -0,0 +1,11 @@
+# type Repository struct {
+#   ID        int64  `xorm:"pk autoincr"`
+# }
+-
+  id: 1
+-
+  id: 2
+-
+  id: 3
+-
+  id: 10

models/migrations/migrations.go

@@ -556,6 +556,8 @@ var migrations = []Migration{
 	NewMigration("Add ignore stale approval column on branch table", v1_22.AddIgnoreStaleApprovalsColumnToProtectedBranchTable),
 	// v285 -> v286
 	NewMigration("Add PreviousDuration to ActionRun", v1_22.AddPreviousDurationToActionRun),
+	// v286 -> v287
+	NewMigration("Add support for SHA256 git repositories", v1_22.AdjustDBForSha256),
 }
 
 // GetCurrentDBVersion returns the current db version

models/migrations/v1_22/v286.go

@@ -0,0 +1,104 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+package v1_22 //nolint
+
+import (
+	"errors"
+	"fmt"
+
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/setting"
+
+	"xorm.io/xorm"
+)
+
+func expandHashReferencesToSha256(x *xorm.Engine) error {
+	alteredTables := [][2]string{
+		{"commit_status", "context_hash"},
+		{"comment", "commit_sha"},
+		{"pull_request", "merge_base"},
+		{"pull_request", "merged_commit_id"},
+		{"review", "commit_id"},
+		{"review_state", "commit_sha"},
+		{"repo_archiver", "commit_id"},
+		{"release", "sha1"},
+		{"repo_indexer_status", "commit_sha"},
+	}
+
+	db := x.NewSession()
+	defer db.Close()
+
+	if err := db.Begin(); err != nil {
+		return err
+	}
+
+	if !setting.Database.Type.IsSQLite3() {
+		if setting.Database.Type.IsMSSQL() {
+			// drop indexes that need to be re-created afterwards
+			droppedIndexes := []string{
+				"DROP INDEX commit_status.IDX_commit_status_context_hash",
+				"DROP INDEX review_state.UQE_review_state_pull_commit_user",
+				"DROP INDEX repo_archiver.UQE_repo_archiver_s",
+			}
+			for _, s := range droppedIndexes {
+				_, err := db.Exec(s)
+				if err != nil {
+					return errors.New(s + " " + err.Error())
+				}
+			}
+		}
+
+		for _, alts := range alteredTables {
+			var err error
+			if setting.Database.Type.IsMySQL() {
+				_, err = db.Exec(fmt.Sprintf("ALTER TABLE `%s` MODIFY COLUMN `%s` VARCHAR(64)", alts[0], alts[1]))
+			} else if setting.Database.Type.IsMSSQL() {
+				_, err = db.Exec(fmt.Sprintf("ALTER TABLE `%s` ALTER COLUMN `%s` VARCHAR(64)", alts[0], alts[1]))
+			} else {
+				_, err = db.Exec(fmt.Sprintf("ALTER TABLE `%s` ALTER COLUMN `%s` TYPE VARCHAR(64)", alts[0], alts[1]))
+			}
+			if err != nil {
+				return fmt.Errorf("alter column '%s' of table '%s' failed: %w", alts[1], alts[0], err)
+			}
+		}
+
+		if setting.Database.Type.IsMSSQL() {
+			recreateIndexes := []string{
+				"CREATE INDEX IDX_commit_status_context_hash ON commit_status(context_hash)",
+				"CREATE UNIQUE INDEX UQE_review_state_pull_commit_user ON review_state(user_id, pull_id, commit_sha)",
+				"CREATE UNIQUE INDEX UQE_repo_archiver_s ON repo_archiver(repo_id, type, commit_id)",
+			}
+			for _, s := range recreateIndexes {
+				_, err := db.Exec(s)
+				if err != nil {
+					return errors.New(s + " " + err.Error())
+				}
+			}
+		}
+	}
+	log.Debug("Updated database tables to hold SHA256 git hash references")
+
+	return db.Commit()
+}
+
+func addObjectFormatNameToRepository(x *xorm.Engine) error {
+	type Repository struct {
+		ObjectFormatName string `xorm:"VARCHAR(6) NOT NULL DEFAULT 'sha1'"`
+	}
+
+	if err := x.Sync(new(Repository)); err != nil {
+		return err
+	}
+
+	// Here to catch weird edge-cases where column constraints above are
+	// not applied by the DB backend
+	_, err := x.Exec("UPDATE repository set object_format_name = 'sha1' WHERE object_format_name = '' or object_format_name IS NULL")
+	return err
+}
+
+func AdjustDBForSha256(x *xorm.Engine) error {
+	if err := expandHashReferencesToSha256(x); err != nil {
+		return err
+	}
+	return addObjectFormatNameToRepository(x)
+}

models/migrations/v1_22/v286_test.go

@@ -0,0 +1,62 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package v1_22 //nolint
+
+import (
+	"testing"
+
+	"code.gitea.io/gitea/models/migrations/base"
+
+	"github.com/stretchr/testify/assert"
+	"xorm.io/xorm"
+)
+
+func PrepareOldRepository(t *testing.T) (*xorm.Engine, func()) {
+	type Repository struct { // old struct
+		ID int64 `xorm:"pk autoincr"`
+	}
+
+	// Prepare and load the testing database
+	return base.PrepareTestEnv(t, 0, new(Repository))
+}
+
+func Test_RepositoryFormat(t *testing.T) {
+	x, deferable := PrepareOldRepository(t)
+	defer deferable()
+
+	type Repository struct {
+		ID               int64  `xorm:"pk autoincr"`
+		ObjectFormatName string `xorg:"not null default('sha1')"`
+	}
+
+	repo := new(Repository)
+
+	// check we have some records to migrate
+	count, err := x.Count(new(Repository))
+	assert.NoError(t, err)
+	assert.EqualValues(t, 4, count)
+
+	assert.NoError(t, AdjustDBForSha256(x))
+
+	repo.ID = 20
+	repo.ObjectFormatName = "sha256"
+	_, err = x.Insert(repo)
+	assert.NoError(t, err)
+
+	count, err = x.Count(new(Repository))
+	assert.NoError(t, err)
+	assert.EqualValues(t, 5, count)
+
+	repo = new(Repository)
+	ok, err := x.ID(2).Get(repo)
+	assert.NoError(t, err)
+	assert.EqualValues(t, true, ok)
+	assert.EqualValues(t, "sha1", repo.ObjectFormatName)
+
+	repo = new(Repository)
+	ok, err = x.ID(20).Get(repo)
+	assert.NoError(t, err)
+	assert.EqualValues(t, true, ok)
+	assert.EqualValues(t, "sha256", repo.ObjectFormatName)
+}

models/pull/review_state.go

@@ -39,7 +39,7 @@ type ReviewState struct {
 	ID           int64                  `xorm:"pk autoincr"`
 	UserID       int64                  `xorm:"NOT NULL UNIQUE(pull_commit_user)"`
 	PullID       int64                  `xorm:"NOT NULL INDEX UNIQUE(pull_commit_user) DEFAULT 0"` // Which PR was the review on?
-	CommitSHA    string                 `xorm:"NOT NULL VARCHAR(40) UNIQUE(pull_commit_user)"`     // Which commit was the head commit for the review?
+	CommitSHA    string                 `xorm:"NOT NULL VARCHAR(64) UNIQUE(pull_commit_user)"`     // Which commit was the head commit for the review?
 	UpdatedFiles map[string]ViewedState `xorm:"NOT NULL LONGTEXT JSON"`                            // Stores for each of the changed files of a PR whether they have been viewed, changed since last viewed, or not viewed
 	UpdatedUnix  timeutil.TimeStamp     `xorm:"updated"`                                           // Is an accurate indicator of the order of commits as we do not expect it to be possible to make reviews on previous commits
 }

models/repo/archiver.go

@@ -33,7 +33,7 @@ type RepoArchiver struct { //revive:disable-line:exported
 	RepoID      int64           `xorm:"index unique(s)"`
 	Type        git.ArchiveType `xorm:"unique(s)"`
 	Status      ArchiverStatus
-	CommitID    string             `xorm:"VARCHAR(40) unique(s)"`
+	CommitID    string             `xorm:"VARCHAR(64) unique(s)"`
 	CreatedUnix timeutil.TimeStamp `xorm:"INDEX NOT NULL created"`
 }
 

models/repo/release.go

@@ -75,7 +75,7 @@ type Release struct {
 	Target           string
 	TargetBehind     string `xorm:"-"` // to handle non-existing or empty target
 	Title            string
-	Sha1             string `xorm:"VARCHAR(40)"`
+	Sha1             string `xorm:"VARCHAR(64)"`
 	NumCommits       int64
 	NumCommitsBehind int64              `xorm:"-"`
 	Note             string             `xorm:"TEXT"`

models/repo/repo.go

@@ -180,7 +180,7 @@ type Repository struct {
 	IsFsckEnabled                   bool               `xorm:"NOT NULL DEFAULT true"`
 	CloseIssuesViaCommitInAnyBranch bool               `xorm:"NOT NULL DEFAULT false"`
 	Topics                          []string           `xorm:"TEXT JSON"`
-	ObjectFormatName                string             `xorm:"-"`
+	ObjectFormatName                string             `xorm:"VARCHAR(6) NOT NULL DEFAULT 'sha1'"`
 
 	TrustModel TrustModelType
 
@@ -276,10 +276,6 @@ func (repo *Repository) AfterLoad() {
 	repo.NumOpenMilestones = repo.NumMilestones - repo.NumClosedMilestones
 	repo.NumOpenProjects = repo.NumProjects - repo.NumClosedProjects
 	repo.NumOpenActionRuns = repo.NumActionRuns - repo.NumClosedActionRuns
-
-	// this is a temporary behaviour to support old repos, next step is to store the object format in the database
-	// and read from database so this line could be removed. To not depend on git module, we use a constant variable here
-	repo.ObjectFormatName = "sha1"
 }
 
 // LoadAttributes loads attributes of the repository.

models/repo/repo_indexer.go

@@ -27,7 +27,7 @@ const (
 type RepoIndexerStatus struct { //revive:disable-line:exported
 	ID          int64           `xorm:"pk autoincr"`
 	RepoID      int64           `xorm:"INDEX(s)"`
-	CommitSha   string          `xorm:"VARCHAR(40)"`
+	CommitSha   string          `xorm:"VARCHAR(64)"`
 	IndexerType RepoIndexerType `xorm:"INDEX(s) NOT NULL DEFAULT 0"`
 }
 

modules/git/blame_sha256_test.go

@@ -0,0 +1,144 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package git
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestReadingBlameOutputSha256(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	t.Run("Without .git-blame-ignore-revs", func(t *testing.T) {
+		repo, err := OpenRepository(ctx, "./tests/repos/repo5_pulls_sha256")
+		assert.NoError(t, err)
+		defer repo.Close()
+
+		commit, err := repo.GetCommit("0b69b7bb649b5d46e14cabb6468685e5dd721290acc7ffe604d37cde57927345")
+		assert.NoError(t, err)
+
+		parts := []*BlamePart{
+			{
+				Sha: "1e35a51dc00fd7de730344c07061acfe80e8117e075ac979b6a29a3a045190ca",
+				Lines: []string{
+					"# test_repo",
+					"Test repository for testing migration from github to gitea",
+				},
+			},
+			{
+				Sha:          "0b69b7bb649b5d46e14cabb6468685e5dd721290acc7ffe604d37cde57927345",
+				Lines:        []string{"", "Do not make any changes to this repo it is used for unit testing"},
+				PreviousSha:  "1e35a51dc00fd7de730344c07061acfe80e8117e075ac979b6a29a3a045190ca",
+				PreviousPath: "README.md",
+			},
+		}
+
+		for _, bypass := range []bool{false, true} {
+			blameReader, err := CreateBlameReader(ctx, Sha256ObjectFormat, "./tests/repos/repo5_pulls_sha256", commit, "README.md", bypass)
+			assert.NoError(t, err)
+			assert.NotNil(t, blameReader)
+			defer blameReader.Close()
+
+			assert.False(t, blameReader.UsesIgnoreRevs())
+
+			for _, part := range parts {
+				actualPart, err := blameReader.NextPart()
+				assert.NoError(t, err)
+				assert.Equal(t, part, actualPart)
+			}
+
+			// make sure all parts have been read
+			actualPart, err := blameReader.NextPart()
+			assert.Nil(t, actualPart)
+			assert.NoError(t, err)
+		}
+	})
+
+	t.Run("With .git-blame-ignore-revs", func(t *testing.T) {
+		repo, err := OpenRepository(ctx, "./tests/repos/repo6_blame_sha256")
+		assert.NoError(t, err)
+		defer repo.Close()
+
+		full := []*BlamePart{
+			{
+				Sha:   "ab2b57a4fa476fb2edb74dafa577caf918561abbaa8fba0c8dc63c412e17a7cc",
+				Lines: []string{"line", "line"},
+			},
+			{
+				Sha:          "9347b0198cd1f25017579b79d0938fa89dba34ad2514f0dd92f6bc975ed1a2fe",
+				Lines:        []string{"changed line"},
+				PreviousSha:  "ab2b57a4fa476fb2edb74dafa577caf918561abbaa8fba0c8dc63c412e17a7cc",
+				PreviousPath: "blame.txt",
+			},
+			{
+				Sha:   "ab2b57a4fa476fb2edb74dafa577caf918561abbaa8fba0c8dc63c412e17a7cc",
+				Lines: []string{"line", "line", ""},
+			},
+		}
+
+		cases := []struct {
+			CommitID       string
+			UsesIgnoreRevs bool
+			Bypass         bool
+			Parts          []*BlamePart
+		}{
+			{
+				CommitID:       "e2f5660e15159082902960af0ed74fc144921d2b0c80e069361853b3ece29ba3",
+				UsesIgnoreRevs: true,
+				Bypass:         false,
+				Parts: []*BlamePart{
+					{
+						Sha:   "ab2b57a4fa476fb2edb74dafa577caf918561abbaa8fba0c8dc63c412e17a7cc",
+						Lines: []string{"line", "line", "changed line", "line", "line", ""},
+					},
+				},
+			},
+			{
+				CommitID:       "e2f5660e15159082902960af0ed74fc144921d2b0c80e069361853b3ece29ba3",
+				UsesIgnoreRevs: false,
+				Bypass:         true,
+				Parts:          full,
+			},
+			{
+				CommitID:       "9347b0198cd1f25017579b79d0938fa89dba34ad2514f0dd92f6bc975ed1a2fe",
+				UsesIgnoreRevs: false,
+				Bypass:         false,
+				Parts:          full,
+			},
+			{
+				CommitID:       "9347b0198cd1f25017579b79d0938fa89dba34ad2514f0dd92f6bc975ed1a2fe",
+				UsesIgnoreRevs: false,
+				Bypass:         false,
+				Parts:          full,
+			},
+		}
+
+		for _, c := range cases {
+			commit, err := repo.GetCommit(c.CommitID)
+			assert.NoError(t, err)
+
+			blameReader, err := CreateBlameReader(ctx, repo.objectFormat, "./tests/repos/repo6_blame_sha256", commit, "blame.txt", c.Bypass)
+			assert.NoError(t, err)
+			assert.NotNil(t, blameReader)
+			defer blameReader.Close()
+
+			assert.Equal(t, c.UsesIgnoreRevs, blameReader.UsesIgnoreRevs())
+
+			for _, part := range c.Parts {
+				actualPart, err := blameReader.NextPart()
+				assert.NoError(t, err)
+				assert.Equal(t, part, actualPart)
+			}
+
+			// make sure all parts have been read
+			actualPart, err := blameReader.NextPart()
+			assert.Nil(t, actualPart)
+			assert.NoError(t, err)
+		}
+	})
+}

modules/git/commit_reader.go

@@ -85,6 +85,8 @@ readLoop:
 				commit.Committer.Decode(data)
 				_, _ = payloadSB.Write(line)
 			case "gpgsig":
+				fallthrough
+			case "gpgsig-sha256": // FIXME: no intertop, so only 1 exists at present.
 				_, _ = signatureSB.Write(data)
 				_ = signatureSB.WriteByte('\n')
 				pgpsig = true

modules/git/commit_sha256_test.go

@@ -0,0 +1,195 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+//go:build !gogit
+
+package git
+
+import (
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestCommitsCountSha256(t *testing.T) {
+	bareRepo1Path := filepath.Join(testReposDir, "repo1_bare_sha256")
+
+	commitsCount, err := CommitsCount(DefaultContext,
+		CommitsCountOptions{
+			RepoPath: bareRepo1Path,
+			Revision: []string{"f004f41359117d319dedd0eaab8c5259ee2263da839dcba33637997458627fdc"},
+		})
+
+	assert.NoError(t, err)
+	assert.Equal(t, int64(3), commitsCount)
+}
+
+func TestCommitsCountWithoutBaseSha256(t *testing.T) {
+	bareRepo1Path := filepath.Join(testReposDir, "repo1_bare_sha256")
+
+	commitsCount, err := CommitsCount(DefaultContext,
+		CommitsCountOptions{
+			RepoPath: bareRepo1Path,
+			Not:      "main",
+			Revision: []string{"branch1"},
+		})
+
+	assert.NoError(t, err)
+	assert.Equal(t, int64(2), commitsCount)
+}
+
+func TestGetFullCommitIDSha256(t *testing.T) {
+	bareRepo1Path := filepath.Join(testReposDir, "repo1_bare_sha256")
+
+	id, err := GetFullCommitID(DefaultContext, bareRepo1Path, "f004f4")
+	assert.NoError(t, err)
+	assert.Equal(t, "f004f41359117d319dedd0eaab8c5259ee2263da839dcba33637997458627fdc", id)
+}
+
+func TestGetFullCommitIDErrorSha256(t *testing.T) {
+	bareRepo1Path := filepath.Join(testReposDir, "repo1_bare_sha256")
+
+	id, err := GetFullCommitID(DefaultContext, bareRepo1Path, "unknown")
+	assert.Empty(t, id)
+	if assert.Error(t, err) {
+		assert.EqualError(t, err, "object does not exist [id: unknown, rel_path: ]")
+	}
+}
+
+func TestCommitFromReaderSha256(t *testing.T) {
+	commitString := `9433b2a62b964c17a4485ae180f45f595d3e69d31b786087775e28c6b6399df0 commit 1114
+tree e7f9e96dd79c09b078cac8b303a7d3b9d65ff9b734e86060a4d20409fd379f9e
+parent 26e9ccc29fad747e9c5d9f4c9ddeb7eff61cc45ef6a8dc258cbeb181afc055e8
+author Adam Majer <amajer@suse.de> 1698676906 +0100
+committer Adam Majer <amajer@suse.de> 1698676906 +0100
+gpgsig-sha256 -----BEGIN PGP SIGNATURE-----
+` + " " + `
+ iQIrBAABCgAtFiEES+fB08xlgTrzSdQvhkUIsBsmec8FAmU/wKoPHGFtYWplckBz
+ dXNlLmRlAAoJEIZFCLAbJnnP4s4PQIJATa++WPzR6/H4etT7bsOGoMyguEJYyWOd
+ aTybplzT7QAL7h2to0QszGabtzMJPIA39xSFZNYNN30voK5YyyYibXluPKgjemfK
+ WNXwF+gkwgZI38gSvKf+vlqI+EYyIFe19wOhiju0m8SIlB5NEPiWHa17q2mqmqqx
+ 1FWa2JdqLPYjAtSLFXeSZegrY5V1FxdemyMUONkg8YO9OSIMZiE0GsnnOXQ3xcT4
+ JTCnmlUxIKw689UiEY80JopUIq+Wl7+qq9507IYYSUCyB6JazL42AKMzVCbD+qBP
+ oOzh/hafYgk9H9qCQXaLbmvs17zXRpicig1bAzqgAy1FDelvpERyRTydEajSLIG6
+ U1cRCkgXCZ0NfsYNPPmBa8b3+rnstypXYTbyMwTln7FfUAaGo6o9JYiPMkzxlmsy
+ zfp/tcaY8+LlBL9aOJjtv+a0p+HrpCGd6CCa4ARfphTLq8QRSSh8uzlB9N+6HnRI
+ VAEUo6ecdDxSpyt2naeg9pKus/BRi7P6g4B1hkk/zZstUX/QP4IQuAJbXjkvsC+X
+ HKRr3NlRM/DygzTyj0gN74uoa0goCIbyAQhiT42nm0cuhM7uN/W0ayrlZjGF1cbR
+ 8NCJUL2Nwj0ywKIavC99Ipkb8AsFwpVT6U6effs6
+ =xybZ
+ -----END PGP SIGNATURE-----
+
+signed commit`
+
+	sha := &Sha256Hash{
+		0x94, 0x33, 0xb2, 0xa6, 0x2b, 0x96, 0x4c, 0x17, 0xa4, 0x48, 0x5a, 0xe1, 0x80, 0xf4, 0x5f, 0x59,
+		0x5d, 0x3e, 0x69, 0xd3, 0x1b, 0x78, 0x60, 0x87, 0x77, 0x5e, 0x28, 0xc6, 0xb6, 0x39, 0x9d, 0xf0,
+	}
+	gitRepo, err := openRepositoryWithDefaultContext(filepath.Join(testReposDir, "repo1_bare_sha256"))
+	assert.NoError(t, err)
+	assert.NotNil(t, gitRepo)
+	defer gitRepo.Close()
+
+	commitFromReader, err := CommitFromReader(gitRepo, sha, strings.NewReader(commitString))
+	assert.NoError(t, err)
+	if !assert.NotNil(t, commitFromReader) {
+		return
+	}
+	assert.EqualValues(t, sha, commitFromReader.ID)
+	assert.EqualValues(t, `-----BEGIN PGP SIGNATURE-----
+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+=xybZ
+-----END PGP SIGNATURE-----
+`, commitFromReader.Signature.Signature)
+	assert.EqualValues(t, `tree e7f9e96dd79c09b078cac8b303a7d3b9d65ff9b734e86060a4d20409fd379f9e
+parent 26e9ccc29fad747e9c5d9f4c9ddeb7eff61cc45ef6a8dc258cbeb181afc055e8
+author Adam Majer <amajer@suse.de> 1698676906 +0100
+committer Adam Majer <amajer@suse.de> 1698676906 +0100
+
+signed commit`, commitFromReader.Signature.Payload)
+	assert.EqualValues(t, "Adam Majer <amajer@suse.de>", commitFromReader.Author.String())
+
+	commitFromReader2, err := CommitFromReader(gitRepo, sha, strings.NewReader(commitString+"\n\n"))
+	assert.NoError(t, err)
+	commitFromReader.CommitMessage += "\n\n"
+	commitFromReader.Signature.Payload += "\n\n"
+	assert.EqualValues(t, commitFromReader, commitFromReader2)
+}
+
+func TestHasPreviousCommitSha256(t *testing.T) {
+	bareRepo1Path := filepath.Join(testReposDir, "repo1_bare_sha256")
+
+	repo, err := openRepositoryWithDefaultContext(bareRepo1Path)
+	assert.NoError(t, err)
+	defer repo.Close()
+
+	commit, err := repo.GetCommit("f004f41359117d319dedd0eaab8c5259ee2263da839dcba33637997458627fdc")
+	assert.NoError(t, err)
+
+	parentSHA := MustIDFromString("b0ec7af4547047f12d5093e37ef8f1b3b5415ed8ee17894d43a34d7d34212e9c")
+	notParentSHA := MustIDFromString("42e334efd04cd36eea6da0599913333c26116e1a537ca76e5b6e4af4dda00236")
+	assert.Equal(t, repo.objectFormat, parentSHA.Type())
+	assert.Equal(t, repo.objectFormat.Name(), "sha256")
+
+	haz, err := commit.HasPreviousCommit(parentSHA)
+	assert.NoError(t, err)
+	assert.True(t, haz)
+
+	hazNot, err := commit.HasPreviousCommit(notParentSHA)
+	assert.NoError(t, err)
+	assert.False(t, hazNot)
+
+	selfNot, err := commit.HasPreviousCommit(commit.ID)
+	assert.NoError(t, err)
+	assert.False(t, selfNot)
+}
+
+func TestGetCommitFileStatusMergesSha256(t *testing.T) {
+	bareRepo1Path := filepath.Join(testReposDir, "repo6_merge_sha256")
+
+	commitFileStatus, err := GetCommitFileStatus(DefaultContext, bareRepo1Path, "d2e5609f630dd8db500f5298d05d16def282412e3e66ed68cc7d0833b29129a1")
+	assert.NoError(t, err)
+
+	expected := CommitFileStatus{
+		[]string{
+			"add_file.txt",
+		},
+		[]string{},
+		[]string{
+			"to_modify.txt",
+		},
+	}
+
+	assert.Equal(t, expected.Added, commitFileStatus.Added)
+	assert.Equal(t, expected.Removed, commitFileStatus.Removed)
+	assert.Equal(t, expected.Modified, commitFileStatus.Modified)
+
+	expected = CommitFileStatus{
+		[]string{},
+		[]string{
+			"to_remove.txt",
+		},
+		[]string{},
+	}
+
+	commitFileStatus, err = GetCommitFileStatus(DefaultContext, bareRepo1Path, "da1ded40dc8e5b7c564171f4bf2fc8370487decfb1cb6a99ef28f3ed73d09172")
+	assert.NoError(t, err)
+
+	assert.Equal(t, expected.Added, commitFileStatus.Added)
+	assert.Equal(t, expected.Removed, commitFileStatus.Removed)
+	assert.Equal(t, expected.Modified, commitFileStatus.Modified)
+}

modules/git/git.go

@@ -185,7 +185,13 @@ func InitFull(ctx context.Context) (err error) {
 		globalCommandArgs = append(globalCommandArgs, "-c", "credential.helper=")
 	}
 	SupportProcReceive = CheckGitVersionAtLeast("2.29") == nil
-	SupportHashSha256 = CheckGitVersionAtLeast("2.42") == nil
+	SupportHashSha256 = CheckGitVersionAtLeast("2.42") == nil && !isGogit
+	if SupportHashSha256 {
+		SupportedObjectFormats = append(SupportedObjectFormats, Sha256ObjectFormat)
+	} else {
+		log.Warn("sha256 hash support is disabled - requires Git >= 2.42. Gogit is currently unsupported")
+	}
+
 	if setting.LFS.StartServer {
 		if CheckGitVersionAtLeast("2.1.2") != nil {
 			return errors.New("LFS server support requires Git >= 2.1.2")

modules/git/object_format.go

@@ -5,6 +5,7 @@ package git
 
 import (
 	"crypto/sha1"
+	"crypto/sha256"
 	"regexp"
 	"strconv"
 )
@@ -12,6 +13,9 @@ import (
 // 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
@@ -29,11 +33,12 @@ type ObjectFormat interface {
 	ComputeHash(t ObjectType, content []byte) ObjectID
 }
 
+/* SHA1 Type */
 type Sha1ObjectFormatImpl struct{}
 
 var (
-	emptyObjectID = &Sha1Hash{}
+	emptySha1ObjectID = &Sha1Hash{}
-	emptyTree     = &Sha1Hash{
+	emptySha1Tree     = &Sha1Hash{
 		0x4b, 0x82, 0x5d, 0xc6, 0x42, 0xcb, 0x6e, 0xb9, 0xa0, 0x60,
 		0xe5, 0x4b, 0xf8, 0xd6, 0x92, 0x88, 0xfb, 0xee, 0x49, 0x04,
 	}
@@ -41,11 +46,11 @@ var (
 
 func (Sha1ObjectFormatImpl) Name() string { return "sha1" }
 func (Sha1ObjectFormatImpl) EmptyObjectID() ObjectID {
-	return emptyObjectID
+	return emptySha1ObjectID
 }
 
 func (Sha1ObjectFormatImpl) EmptyTree() ObjectID {
-	return emptyTree
+	return emptySha1Tree
 }
 func (Sha1ObjectFormatImpl) FullLength() int { return 40 }
 func (Sha1ObjectFormatImpl) IsValid(input string) bool {
@@ -72,11 +77,59 @@ func (h Sha1ObjectFormatImpl) ComputeHash(t ObjectType, content []byte) ObjectID
 	return &sha1
 }
 
-var Sha1ObjectFormat ObjectFormat = Sha1ObjectFormatImpl{}
+/* 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,
-	// TODO: add sha256
 }
 
 func ObjectFormatFromName(name string) ObjectFormat {

modules/git/object_id.go

@@ -16,6 +16,7 @@ type ObjectID interface {
 	Type() ObjectFormat
 }
 
+/* SHA1 */
 type Sha1Hash [20]byte
 
 func (h *Sha1Hash) String() string {
@@ -39,6 +40,21 @@ func MustIDFromString(hexHash string) ObjectID {
 	return id
 }
 
+/* SHA256 */
+type Sha256Hash [32]byte
+
+func (h *Sha256Hash) String() string {
+	return hex.EncodeToString(h[:])
+}
+
+func (h *Sha256Hash) IsZero() bool {
+	empty := Sha256Hash{}
+	return bytes.Equal(empty[:], h[:])
+}
+func (h *Sha256Hash) RawValue() []byte { return h[:] }
+func (*Sha256Hash) Type() ObjectFormat { return Sha256ObjectFormat }
+
+/* utility */
 func NewIDFromString(hexHash string) (ObjectID, error) {
 	var theObjectFormat ObjectFormat
 	for _, objectFormat := range SupportedObjectFormats {

modules/git/object_id_gogit.go

@@ -13,6 +13,8 @@ func ParseGogitHash(h plumbing.Hash) ObjectID {
 	switch hash.Size {
 	case 20:
 		return Sha1ObjectFormat.MustID(h[:])
+	case 32:
+		return Sha256ObjectFormat.MustID(h[:])
 	}
 
 	return nil

modules/git/repo.go

@@ -97,15 +97,12 @@ func InitRepository(ctx context.Context, repoPath string, bare bool, objectForma
 	}
 
 	cmd := NewCommand(ctx, "init")
-	if SupportHashSha256 {
+
-		if objectFormatName == "" {
-			objectFormatName = Sha1ObjectFormat.Name()
-		}
 	if !IsValidObjectFormat(objectFormatName) {
 		return fmt.Errorf("invalid object format: %s", objectFormatName)
 	}
 	cmd.AddOptionValues("--object-format", objectFormatName)
-	}
+
 	if bare {
 		cmd.AddArguments("--bare")
 	}

modules/git/repo_base.go

@@ -8,6 +8,8 @@ import (
 	"io"
 )
 
+var isGogit bool
+
 // contextKey is a value for use with context.WithValue.
 type contextKey struct {
 	name string

modules/git/repo_base_gogit.go

@@ -21,6 +21,10 @@ import (
 	"github.com/go-git/go-git/v5/storage/filesystem"
 )
 
+func init() {
+	isGogit = true
+}
+
 // Repository represents a Git repository.
 type Repository struct {
 	Path string

modules/git/repo_base_nogogit.go

@@ -15,6 +15,10 @@ import (
 	"code.gitea.io/gitea/modules/log"
 )
 
+func init() {
+	isGogit = false
+}
+
 // Repository represents a Git repository.
 type Repository struct {
 	Path string

modules/git/tests/repos/repo1_bare_sha256/HEAD

@@ -0,0 +1 @@
+ref: refs/heads/main

modules/git/tests/repos/repo1_bare_sha256/config

@@ -0,0 +1,6 @@
+[core]
+	repositoryformatversion = 1
+	filemode = true
+	bare = true
+[extensions]
+	objectformat = sha256

modules/git/tests/repos/repo1_bare_sha256/description

@@ -0,0 +1 @@
+Unnamed repository; edit this file 'description' to name the repository.

modules/git/tests/repos/repo1_bare_sha256/info/exclude

@@ -0,0 +1,6 @@
+# git ls-files --others --exclude-from=.git/info/exclude
+# Lines that start with '#' are comments.
+# For a project mostly in C, the following would be a good set of
+# exclude patterns (uncomment them if you want to use them):
+# *.[oa]
+# *~

modules/git/tests/repos/repo1_bare_sha256/info/refs

@@ -0,0 +1,7 @@
+42e334efd04cd36eea6da0599913333c26116e1a537ca76e5b6e4af4dda00236	refs/heads/branch1
+5bc2249e32e0ba40a08879fba2bd4e97a13cb345831549f4bc5649525da8f6cc	refs/heads/branch2
+9433b2a62b964c17a4485ae180f45f595d3e69d31b786087775e28c6b6399df0	refs/heads/main
+29a82d4fc02e19190fb489cc90d5730ed91970b49f4e39acda2798b3dd4f814e	refs/tags/signed-tag
+9433b2a62b964c17a4485ae180f45f595d3e69d31b786087775e28c6b6399df0	refs/tags/signed-tag^{}
+171822a62559f3aa28a00aa3785dbe915d6a8eb02712682740db44fc8bd2187a	refs/tags/test
+6aae864a3d1d0d6a5be0cc64028c1e7021e2632b031fd8eb82afc5a283d1c3d1	refs/tags/test^{}

modules/git/tests/repos/repo1_bare_sha256/objects/info/packs

@@ -0,0 +1,2 @@
+P pack-c01aa121b9c5e345fe0da2f9be78665970b0c38c6b495d5fc034bc7a7b95334b.pack
+

modules/git/tests/repos/repo1_bare_sha256/packed-refs

@@ -0,0 +1,8 @@
+# pack-refs with: peeled fully-peeled sorted 
+42e334efd04cd36eea6da0599913333c26116e1a537ca76e5b6e4af4dda00236 refs/heads/branch1
+5bc2249e32e0ba40a08879fba2bd4e97a13cb345831549f4bc5649525da8f6cc refs/heads/branch2
+9433b2a62b964c17a4485ae180f45f595d3e69d31b786087775e28c6b6399df0 refs/heads/main
+29a82d4fc02e19190fb489cc90d5730ed91970b49f4e39acda2798b3dd4f814e refs/tags/signed-tag
+^9433b2a62b964c17a4485ae180f45f595d3e69d31b786087775e28c6b6399df0
+171822a62559f3aa28a00aa3785dbe915d6a8eb02712682740db44fc8bd2187a refs/tags/test
+^6aae864a3d1d0d6a5be0cc64028c1e7021e2632b031fd8eb82afc5a283d1c3d1

modules/git/tests/repos/repo1_bare_sha256/refs/heads/main

@@ -0,0 +1 @@
+9433b2a62b964c17a4485ae180f45f595d3e69d31b786087775e28c6b6399df0

modules/git/tests/repos/repo5_pulls_sha256/HEAD

@@ -0,0 +1 @@
+ref: refs/heads/main

modules/git/tests/repos/repo5_pulls_sha256/config

@@ -0,0 +1,6 @@
+[core]
+	repositoryformatversion = 1
+	filemode = true
+	bare = true
+[extensions]
+	objectformat = sha256

modules/git/tests/repos/repo5_pulls_sha256/description

@@ -0,0 +1 @@
+Unnamed repository; edit this file 'description' to name the repository.

modules/git/tests/repos/repo5_pulls_sha256/info/refs

@@ -0,0 +1,4 @@
+35ecd0f946c8baeb76fa5a3876f46bf35218655e2304d8505026fa4bfb496a4b	refs/heads/main
+35ecd0f946c8baeb76fa5a3876f46bf35218655e2304d8505026fa4bfb496a4b	refs/heads/main-clone
+7f50a4906503378b0bbb7d61bd2ca8d8d8ff4f7a2474980f99402d742ccc9665	refs/heads/test-patch-1
+1e35a51dc00fd7de730344c07061acfe80e8117e075ac979b6a29a3a045190ca	refs/tags/v0.9.99

modules/git/tests/repos/repo5_pulls_sha256/objects/info/packs

@@ -0,0 +1,2 @@
+P pack-bfe8f09d42ef5dd1610bf42641fe145d4a02b788eb26c31022a362312660a29d.pack
+

modules/git/tests/repos/repo5_pulls_sha256/packed-refs

@@ -0,0 +1,5 @@
+# pack-refs with: peeled fully-peeled sorted 
+35ecd0f946c8baeb76fa5a3876f46bf35218655e2304d8505026fa4bfb496a4b refs/heads/main
+35ecd0f946c8baeb76fa5a3876f46bf35218655e2304d8505026fa4bfb496a4b refs/heads/main-clone
+7f50a4906503378b0bbb7d61bd2ca8d8d8ff4f7a2474980f99402d742ccc9665 refs/heads/test-patch-1
+1e35a51dc00fd7de730344c07061acfe80e8117e075ac979b6a29a3a045190ca refs/tags/v0.9.99

modules/git/tests/repos/repo5_pulls_sha256/refs/heads/main

@@ -0,0 +1 @@
+35ecd0f946c8baeb76fa5a3876f46bf35218655e2304d8505026fa4bfb496a4b

modules/git/tests/repos/repo6_blame_sha256/HEAD

@@ -0,0 +1 @@
+ref: refs/heads/main

modules/git/tests/repos/repo6_blame_sha256/config

@@ -0,0 +1,6 @@
+[core]
+	repositoryformatversion = 1
+	filemode = true
+	bare = true
+[extensions]
+	objectformat = sha256

modules/git/tests/repos/repo6_blame_sha256/description

@@ -0,0 +1 @@
+Unnamed repository; edit this file 'description' to name the repository.

modules/git/tests/repos/repo6_blame_sha256/info/exclude

@@ -0,0 +1,6 @@
+# git ls-files --others --exclude-from=.git/info/exclude
+# Lines that start with '#' are comments.
+# For a project mostly in C, the following would be a good set of
+# exclude patterns (uncomment them if you want to use them):
+# *.[oa]
+# *~

modules/git/tests/repos/repo6_blame_sha256/info/refs

@@ -0,0 +1 @@
+e2f5660e15159082902960af0ed74fc144921d2b0c80e069361853b3ece29ba3	refs/heads/main

modules/git/tests/repos/repo6_blame_sha256/objects/info/packs

@@ -0,0 +1,2 @@
+P pack-fcb8a221b76025fd8415d3c562b611ac24312a5ffc3d3703d7c5cc906bdaee8e.pack
+

modules/git/tests/repos/repo6_blame_sha256/packed-refs

@@ -0,0 +1,2 @@
+# pack-refs with: peeled fully-peeled sorted 
+e2f5660e15159082902960af0ed74fc144921d2b0c80e069361853b3ece29ba3 refs/heads/main

modules/git/tests/repos/repo6_blame_sha256/refs/refs/main

@@ -0,0 +1 @@
+e2f5660e15159082902960af0ed74fc144921d2b0c80e069361853b3ece29ba3

modules/git/tests/repos/repo6_merge_sha256/HEAD

@@ -0,0 +1 @@
+ref: refs/heads/main

modules/git/tests/repos/repo6_merge_sha256/config

@@ -0,0 +1,6 @@
+[core]
+	repositoryformatversion = 1
+	filemode = true
+	bare = true
+[extensions]
+	objectformat = sha256

modules/git/tests/repos/repo6_merge_sha256/description

@@ -0,0 +1 @@
+Unnamed repository; edit this file 'description' to name the repository.

modules/git/tests/repos/repo6_merge_sha256/info/exclude

@@ -0,0 +1,6 @@
+# git ls-files --others --exclude-from=.git/info/exclude
+# Lines that start with '#' are comments.
+# For a project mostly in C, the following would be a good set of
+# exclude patterns (uncomment them if you want to use them):
+# *.[oa]
+# *~

modules/git/tests/repos/repo6_merge_sha256/info/refs

@@ -0,0 +1,4 @@
+d2e5609f630dd8db500f5298d05d16def282412e3e66ed68cc7d0833b29129a1	refs/heads/main
+b45258e9823233edea2d40d183742f29630e1e69300479fb4a55eabfe9b1d8bf	refs/heads/merge/add_file
+ff2b996e2fa366146300e4c9e51ccb6818147b360e46fa1437334f4a690955ce	refs/heads/merge/modify_file
+da1ded40dc8e5b7c564171f4bf2fc8370487decfb1cb6a99ef28f3ed73d09172	refs/heads/merge/remove_file

modules/git/tests/repos/repo6_merge_sha256/objects/info/packs

@@ -0,0 +1,3 @@
+P pack-2fff0848f8d8eab8f7902ac91ab6a096c7530f577d5c0a79c63d9ac2b44f7510.pack
+P pack-65162b86afdbac3c566696d487e67bb2a4a5501ca1fa3528fad8a9474fba7e50.pack
+

modules/git/tests/repos/repo6_merge_sha256/packed-refs

@@ -0,0 +1,5 @@
+# pack-refs with: peeled fully-peeled sorted 
+d2e5609f630dd8db500f5298d05d16def282412e3e66ed68cc7d0833b29129a1 refs/heads/main
+b45258e9823233edea2d40d183742f29630e1e69300479fb4a55eabfe9b1d8bf refs/heads/merge/add_file
+ff2b996e2fa366146300e4c9e51ccb6818147b360e46fa1437334f4a690955ce refs/heads/merge/modify_file
+da1ded40dc8e5b7c564171f4bf2fc8370487decfb1cb6a99ef28f3ed73d09172 refs/heads/merge/remove_file

modules/git/tests/repos/repo6_merge_sha256/refs/heads/main

@@ -0,0 +1 @@
+d2e5609f630dd8db500f5298d05d16def282412e3e66ed68cc7d0833b29129a1

modules/markup/html.go

@@ -45,19 +45,19 @@ var (
 
 	// valid chars in encoded path and parameter: [-+~_%.a-zA-Z0-9/]
 
-	// sha1CurrentPattern matches string that represents a commit SHA, e.g. d8a994ef243349f321568f9e36d5c3f444b99cae
+	// hashCurrentPattern matches string that represents a commit SHA, e.g. d8a994ef243349f321568f9e36d5c3f444b99cae
-	// Although SHA1 hashes are 40 chars long, the regex matches the hash from 7 to 40 chars in length
+	// Although SHA1 hashes are 40 chars long, SHA256 are 64, the regex matches the hash from 7 to 64 chars in length
 	// so that abbreviated hash links can be used as well. This matches git and GitHub usability.
-	sha1CurrentPattern = regexp.MustCompile(`(?:\s|^|\(|\[)([0-9a-f]{7,40})(?:\s|$|\)|\]|[.,](\s|$))`)
+	hashCurrentPattern = regexp.MustCompile(`(?:\s|^|\(|\[)([0-9a-f]{7,64})(?:\s|$|\)|\]|[.,](\s|$))`)
 
 	// shortLinkPattern matches short but difficult to parse [[name|link|arg=test]] syntax
 	shortLinkPattern = regexp.MustCompile(`\[\[(.*?)\]\](\w*)`)
 
 	// anySHA1Pattern splits url containing SHA into parts
-	anySHA1Pattern = regexp.MustCompile(`https?://(?:\S+/){4,5}([0-9a-f]{40})(/[-+~_%.a-zA-Z0-9/]+)?(#[-+~_%.a-zA-Z0-9]+)?`)
+	anyHashPattern = regexp.MustCompile(`https?://(?:\S+/){4,5}([0-9a-f]{40,64})(/[-+~_%.a-zA-Z0-9/]+)?(#[-+~_%.a-zA-Z0-9]+)?`)
 
 	// comparePattern matches "http://domain/org/repo/compare/COMMIT1...COMMIT2#hash"
-	comparePattern = regexp.MustCompile(`https?://(?:\S+/){4,5}([0-9a-f]{7,40})(\.\.\.?)([0-9a-f]{7,40})?(#[-+~_%.a-zA-Z0-9]+)?`)
+	comparePattern = regexp.MustCompile(`https?://(?:\S+/){4,5}([0-9a-f]{7,64})(\.\.\.?)([0-9a-f]{7,64})?(#[-+~_%.a-zA-Z0-9]+)?`)
 
 	validLinksPattern = regexp.MustCompile(`^[a-z][\w-]+://`)
 
@@ -171,13 +171,13 @@ type processor func(ctx *RenderContext, node *html.Node)
 var defaultProcessors = []processor{
 	fullIssuePatternProcessor,
 	comparePatternProcessor,
-	fullSha1PatternProcessor,
+	fullHashPatternProcessor,
 	shortLinkProcessor,
 	linkProcessor,
 	mentionProcessor,
 	issueIndexPatternProcessor,
 	commitCrossReferencePatternProcessor,
-	sha1CurrentPatternProcessor,
+	hashCurrentPatternProcessor,
 	emailAddressProcessor,
 	emojiProcessor,
 	emojiShortCodeProcessor,
@@ -199,12 +199,12 @@ func PostProcess(
 var commitMessageProcessors = []processor{
 	fullIssuePatternProcessor,
 	comparePatternProcessor,
-	fullSha1PatternProcessor,
+	fullHashPatternProcessor,
 	linkProcessor,
 	mentionProcessor,
 	issueIndexPatternProcessor,
 	commitCrossReferencePatternProcessor,
-	sha1CurrentPatternProcessor,
+	hashCurrentPatternProcessor,
 	emailAddressProcessor,
 	emojiProcessor,
 	emojiShortCodeProcessor,
@@ -231,12 +231,12 @@ func RenderCommitMessage(
 var commitMessageSubjectProcessors = []processor{
 	fullIssuePatternProcessor,
 	comparePatternProcessor,
-	fullSha1PatternProcessor,
+	fullHashPatternProcessor,
 	linkProcessor,
 	mentionProcessor,
 	issueIndexPatternProcessor,
 	commitCrossReferencePatternProcessor,
-	sha1CurrentPatternProcessor,
+	hashCurrentPatternProcessor,
 	emojiShortCodeProcessor,
 	emojiProcessor,
 }
@@ -273,7 +273,7 @@ func RenderIssueTitle(
 	return renderProcessString(ctx, []processor{
 		issueIndexPatternProcessor,
 		commitCrossReferencePatternProcessor,
-		sha1CurrentPatternProcessor,
+		hashCurrentPatternProcessor,
 		emojiShortCodeProcessor,
 		emojiProcessor,
 	}, title)
@@ -946,15 +946,15 @@ func commitCrossReferencePatternProcessor(ctx *RenderContext, node *html.Node) {
 	}
 }
 
-// fullSha1PatternProcessor renders SHA containing URLs
+// fullHashPatternProcessor renders SHA containing URLs
-func fullSha1PatternProcessor(ctx *RenderContext, node *html.Node) {
+func fullHashPatternProcessor(ctx *RenderContext, node *html.Node) {
 	if ctx.Metas == nil {
 		return
 	}
 
 	next := node.NextSibling
 	for node != nil && node != next {
-		m := anySHA1Pattern.FindStringSubmatchIndex(node.Data)
+		m := anyHashPattern.FindStringSubmatchIndex(node.Data)
 		if m == nil {
 			return
 		}
@@ -1111,9 +1111,9 @@ func emojiProcessor(ctx *RenderContext, node *html.Node) {
 	}
 }
 
-// sha1CurrentPatternProcessor renders SHA1 strings to corresponding links that
+// hashCurrentPatternProcessor renders SHA1 strings to corresponding links that
 // are assumed to be in the same repository.
-func sha1CurrentPatternProcessor(ctx *RenderContext, node *html.Node) {
+func hashCurrentPatternProcessor(ctx *RenderContext, node *html.Node) {
 	if ctx.Metas == nil || ctx.Metas["user"] == "" || ctx.Metas["repo"] == "" || ctx.Metas["repoPath"] == "" {
 		return
 	}
@@ -1124,7 +1124,7 @@ func sha1CurrentPatternProcessor(ctx *RenderContext, node *html.Node) {
 		ctx.ShaExistCache = make(map[string]bool)
 	}
 	for node != nil && node != next && start < len(node.Data) {
-		m := sha1CurrentPattern.FindStringSubmatchIndex(node.Data[start:])
+		m := hashCurrentPattern.FindStringSubmatchIndex(node.Data[start:])
 		if m == nil {
 			return
 		}

modules/markup/html_internal_test.go

@@ -390,10 +390,10 @@ func TestRegExp_sha1CurrentPattern(t *testing.T) {
 	}
 
 	for _, testCase := range trueTestCases {
-		assert.True(t, sha1CurrentPattern.MatchString(testCase))
+		assert.True(t, hashCurrentPattern.MatchString(testCase))
 	}
 	for _, testCase := range falseTestCases {
-		assert.False(t, sha1CurrentPattern.MatchString(testCase))
+		assert.False(t, hashCurrentPattern.MatchString(testCase))
 	}
 }
 
@@ -427,7 +427,7 @@ func TestRegExp_anySHA1Pattern(t *testing.T) {
 	}
 
 	for k, v := range testCases {
-		assert.Equal(t, anySHA1Pattern.FindStringSubmatch(k)[1:], v)
+		assert.Equal(t, anyHashPattern.FindStringSubmatch(k)[1:], v)
 	}
 }
 

modules/references/references.go

@@ -39,7 +39,7 @@ var (
 	crossReferenceIssueNumericPattern = regexp.MustCompile(`(?:\s|^|\(|\[)([0-9a-zA-Z-_\.]+/[0-9a-zA-Z-_\.]+[#!][0-9]+)(?:\s|$|\)|\]|[:;,.?!]\s|[:;,.?!]$)`)
 	// crossReferenceCommitPattern matches a string that references a commit in a different repository
 	// e.g. go-gitea/gitea@d8a994ef, go-gitea/gitea@d8a994ef243349f321568f9e36d5c3f444b99cae (7-40 characters)
-	crossReferenceCommitPattern = regexp.MustCompile(`(?:\s|^|\(|\[)([0-9a-zA-Z-_\.]+)/([0-9a-zA-Z-_\.]+)@([0-9a-f]{7,40})(?:\s|$|\)|\]|[:;,.?!]\s|[:;,.?!]$)`)
+	crossReferenceCommitPattern = regexp.MustCompile(`(?:\s|^|\(|\[)([0-9a-zA-Z-_\.]+)/([0-9a-zA-Z-_\.]+)@([0-9a-f]{7,64})(?:\s|$|\)|\]|[:;,.?!]\s|[:;,.?!]$)`)
 	// spaceTrimmedPattern let's find the trailing space
 	spaceTrimmedPattern = regexp.MustCompile(`(?:.*[0-9a-zA-Z-_])\s`)
 	// timeLogPattern matches string for time tracking

modules/references/references_test.go

@@ -343,7 +343,7 @@ func TestFindRenderizableCommitCrossReference(t *testing.T) {
 			},
 		},
 		{
-			Input:    "go-gitea/gitea@abcd1234abcd1234abcd1234abcd1234abcd12340", // longer than 40 characters
+			Input:    "go-gitea/gitea@abcd1234abcd1234abcd1234abcd1234abcd12341234512345123451234512345", // longer than 64 characters
 			Expected: nil,
 		},
 		{

modules/structs/repo.go

@@ -105,6 +105,9 @@ type Repository struct {
 	AvatarURL                     string           `json:"avatar_url"`
 	Internal                      bool             `json:"internal"`
 	MirrorInterval                string           `json:"mirror_interval"`
+	// ObjectFormatName of the underlying git repository
+	// enum: sha1,sha256
+	ObjectFormatName string `json:"object_format_name"`
 	// swagger:strfmt date-time
 	MirrorUpdated time.Time     `json:"mirror_updated,omitempty"`
 	RepoTransfer  *RepoTransfer `json:"repo_transfer"`
@@ -139,6 +142,9 @@ type CreateRepoOption struct {
 	// TrustModel of the repository
 	// enum: default,collaborator,committer,collaboratorcommitter
 	TrustModel string `json:"trust_model"`
+	// ObjectFormatName of the underlying git repository
+	// enum: sha1,sha256
+	ObjectFormatName string `json:"object_format_name" binding:"MaxSize(6)"`
 }
 
 // EditRepoOption options when editing a repository's properties

modules/templates/util_string.go

@@ -41,3 +41,7 @@ func (su *StringUtils) Cut(s, sep string) []any {
 func (su *StringUtils) EllipsisString(s string, max int) string {
 	return base.EllipsisString(s, max)
 }
+
+func (su *StringUtils) ToUpper(s string) string {
+	return strings.ToUpper(s)
+}

options/locale/locale_en-US.ini

@@ -970,6 +970,8 @@ issue_labels_helper = Select an issue label set.
 license = License
 license_helper = Select a license file.
 license_helper_desc = A license governs what others can and can't do with your code. Not sure which one is right for your project? See <a target="_blank" rel="noopener noreferrer" href="%s">Choose a license.</a>
+object_format = Object Format
+object_format_helper = Object format of the repository. Cannot be changed later. SHA1 is most compatible.
 readme = README
 readme_helper = Select a README file template.
 readme_helper_desc = This is the place where you can write a complete description for your project.
@@ -1038,6 +1040,7 @@ desc.public = Public
 desc.template = Template
 desc.internal = Internal
 desc.archived = Archived
+desc.sha256 = SHA256
 
 template.items = Template Items
 template.git_content = Git Content (Default Branch)

routers/api/v1/repo/repo.go

@@ -253,7 +253,7 @@ func CreateUserRepo(ctx *context.APIContext, owner *user_model.User, opt api.Cre
 		DefaultBranch:    opt.DefaultBranch,
 		TrustModel:       repo_model.ToTrustModel(opt.TrustModel),
 		IsTemplate:       opt.Template,
-		ObjectFormatName: git.Sha1ObjectFormat.Name(),
+		ObjectFormatName: opt.ObjectFormatName,
 	})
 	if err != nil {
 		if repo_model.IsErrRepoAlreadyExist(err) {

routers/web/githttp.go

@@ -36,8 +36,8 @@ func gitHTTPRouters(m *web.Route) {
 		m.Methods("GET,OPTIONS", "/objects/info/http-alternates", repo.GetTextFile("objects/info/http-alternates"))
 		m.Methods("GET,OPTIONS", "/objects/info/packs", repo.GetInfoPacks)
 		m.Methods("GET,OPTIONS", "/objects/info/{file:[^/]*}", repo.GetTextFile(""))
-		m.Methods("GET,OPTIONS", "/objects/{head:[0-9a-f]{2}}/{hash:[0-9a-f]{38}}", repo.GetLooseObject)
+		m.Methods("GET,OPTIONS", "/objects/{head:[0-9a-f]{2}}/{hash:[0-9a-f]{38,62}}", repo.GetLooseObject)
-		m.Methods("GET,OPTIONS", "/objects/pack/pack-{file:[0-9a-f]{40}}.pack", repo.GetPackFile)
+		m.Methods("GET,OPTIONS", "/objects/pack/pack-{file:[0-9a-f]{40,64}}.pack", repo.GetPackFile)
-		m.Methods("GET,OPTIONS", "/objects/pack/pack-{file:[0-9a-f]{40}}.idx", repo.GetIdxFile)
+		m.Methods("GET,OPTIONS", "/objects/pack/pack-{file:[0-9a-f]{40,64}}.idx", repo.GetIdxFile)
 	}, ignSignInAndCsrf, requireSignIn, repo.HTTPGitEnabledHandler, repo.CorsHandler(), context_service.UserAssignmentWeb())
 }

routers/web/repo/repo.go

@@ -159,7 +159,6 @@ func Create(ctx *context.Context) {
 	ctx.Data["private"] = getRepoPrivate(ctx)
 	ctx.Data["IsForcedPrivate"] = setting.Repository.ForcePrivate
 	ctx.Data["default_branch"] = setting.Repository.DefaultBranch
-	ctx.Data["hash_type"] = "sha1"
 
 	ctxUser := checkContextUser(ctx, ctx.FormInt64("org"))
 	if ctx.Written() {
@@ -179,6 +178,8 @@ func Create(ctx *context.Context) {
 
 	ctx.Data["CanCreateRepo"] = ctx.Doer.CanCreateRepo()
 	ctx.Data["MaxCreationLimit"] = ctx.Doer.MaxCreationLimit()
+	ctx.Data["SupportedObjectFormats"] = git.SupportedObjectFormats
+	ctx.Data["DefaultObjectFormat"] = git.Sha1ObjectFormat
 
 	ctx.HTML(http.StatusOK, tplCreate)
 }

routers/web/web.go

@@ -1235,7 +1235,7 @@ func registerRoutes(m *web.Route) {
 					Post(web.Bind(forms.UploadRepoFileForm{}), repo.UploadFilePost)
 				m.Combo("/_diffpatch/*").Get(repo.NewDiffPatch).
 					Post(web.Bind(forms.EditRepoFileForm{}), repo.NewDiffPatchPost)
-				m.Combo("/_cherrypick/{sha:([a-f0-9]{7,40})}/*").Get(repo.CherryPick).
+				m.Combo("/_cherrypick/{sha:([a-f0-9]{7,64})}/*").Get(repo.CherryPick).
 					Post(web.Bind(forms.CherryPickForm{}), repo.CherryPickPost)
 			}, repo.MustBeEditable)
 			m.Group("", func() {
@@ -1377,8 +1377,8 @@ func registerRoutes(m *web.Route) {
 			m.Combo("/*").
 				Get(repo.Wiki).
 				Post(context.RepoMustNotBeArchived(), reqSignIn, reqRepoWikiWriter, web.Bind(forms.NewWikiForm{}), repo.WikiPost)
-			m.Get("/commit/{sha:[a-f0-9]{7,40}}", repo.SetEditorconfigIfExists, repo.SetDiffViewStyle, repo.SetWhitespaceBehavior, repo.Diff)
+			m.Get("/commit/{sha:[a-f0-9]{7,64}}", repo.SetEditorconfigIfExists, repo.SetDiffViewStyle, repo.SetWhitespaceBehavior, repo.Diff)
-			m.Get("/commit/{sha:[a-f0-9]{7,40}}.{ext:patch|diff}", repo.RawDiff)
+			m.Get("/commit/{sha:[a-f0-9]{7,64}}.{ext:patch|diff}", repo.RawDiff)
 		}, repo.MustEnableWiki, func(ctx *context.Context) {
 			ctx.Data["PageIsWiki"] = true
 			ctx.Data["CloneButtonOriginLink"] = ctx.Repo.Repository.WikiCloneLink()
@@ -1498,9 +1498,9 @@ func registerRoutes(m *web.Route) {
 
 		m.Group("", func() {
 			m.Get("/graph", repo.Graph)
-			m.Get("/commit/{sha:([a-f0-9]{7,40})$}", repo.SetEditorconfigIfExists, repo.SetDiffViewStyle, repo.SetWhitespaceBehavior, repo.Diff)
+			m.Get("/commit/{sha:([a-f0-9]{7,64})$}", repo.SetEditorconfigIfExists, repo.SetDiffViewStyle, repo.SetWhitespaceBehavior, repo.Diff)
-			m.Get("/commit/{sha:([a-f0-9]{7,40})$}/load-branches-and-tags", repo.LoadBranchesAndTags)
+			m.Get("/commit/{sha:([a-f0-9]{7,64})$}/load-branches-and-tags", repo.LoadBranchesAndTags)
-			m.Get("/cherry-pick/{sha:([a-f0-9]{7,40})$}", repo.SetEditorconfigIfExists, repo.CherryPick)
+			m.Get("/cherry-pick/{sha:([a-f0-9]{7,64})$}", repo.SetEditorconfigIfExists, repo.CherryPick)
 		}, repo.MustBeNotEmpty, context.RepoRef(), reqRepoCodeReader)
 
 		m.Get("/rss/branch/*", context.RepoRefByType(context.RepoRefBranch), feedEnabled, feed.RenderBranchFeed)
@@ -1517,7 +1517,7 @@ func registerRoutes(m *web.Route) {
 		m.Group("", func() {
 			m.Get("/forks", repo.Forks)
 		}, context.RepoRef(), reqRepoCodeReader)
-		m.Get("/commit/{sha:([a-f0-9]{7,40})}.{ext:patch|diff}", repo.MustBeNotEmpty, reqRepoCodeReader, repo.RawDiff)
+		m.Get("/commit/{sha:([a-f0-9]{7,64})}.{ext:patch|diff}", repo.MustBeNotEmpty, reqRepoCodeReader, repo.RawDiff)
 	}, ignSignIn, context.RepoAssignment, context.UnitTypes())
 
 	m.Post("/{username}/{reponame}/lastcommit/*", ignSignInAndCsrf, context.RepoAssignment, context.UnitTypes(), context.RepoRefByType(context.RepoRefCommit), reqRepoCodeReader, repo.LastCommit)

services/repository/create.go

@@ -217,6 +217,10 @@ func CreateRepositoryDirectly(ctx context.Context, doer, u *user_model.User, opt
 		}
 	}
 
+	if opts.ObjectFormatName == "" {
+		opts.ObjectFormatName = git.Sha1ObjectFormat.Name()
+	}
+
 	repo := &repo_model.Repository{
 		OwnerID:                         u.ID,
 		Owner:                           u,

services/repository/fork.go

@@ -87,6 +87,7 @@ func ForkRepository(ctx context.Context, doer, owner *user_model.User, opts Fork
 		IsEmpty:          opts.BaseRepo.IsEmpty,
 		IsFork:           true,
 		ForkID:           opts.BaseRepo.ID,
+		ObjectFormatName: opts.BaseRepo.ObjectFormatName,
 	}
 
 	oldRepoPath := opts.BaseRepo.RepoPath()

templates/admin/repo/list.tmpl

@@ -67,6 +67,9 @@
 								{{if .IsTemplate}}
 									<span class="ui basic label">{{ctx.Locale.Tr "repo.desc.template"}}</span>
 								{{end}}
+								{{if eq .ObjectFormatName "sha256"}}
+									<span class="ui basic label">{{ctx.Locale.Tr "repo.desc.sha256"}}</span>
+								{{end}}
 								{{if .IsMirror}}
 									{{svg "octicon-mirror"}}
 								{{else if .IsFork}}

templates/explore/repo_list.tmpl

@@ -25,6 +25,9 @@
 							{{if .IsTemplate}}
 								<span class="ui basic label">{{ctx.Locale.Tr "repo.desc.template"}}</span>
 							{{end}}
+							{{if eq .ObjectFormatName "sha256"}}
+								<span class="ui basic label">{{ctx.Locale.Tr "repo.desc.sha256"}}</span>
+							{{end}}
 						</span>
 					</div>
 					<div class="flex-item-trailing">

templates/repo/commits_list.tmpl

@@ -3,7 +3,7 @@
 			<thead>
 				<tr>
 					<th class="three wide">{{ctx.Locale.Tr "repo.commits.author"}}</th>
-					<th class="two wide sha">SHA1</th>
+					<th class="two wide sha">{{StringUtils.ToUpper $.Repository.ObjectFormatName}}</th>
 					<th class="eight wide message">{{ctx.Locale.Tr "repo.commits.message"}}</th>
 					<th class="two wide right aligned">{{ctx.Locale.Tr "repo.commits.date"}}</th>
 					<th class="one wide"></th>

templates/repo/create.tmpl

@@ -185,6 +185,19 @@
 							<input id="default_branch" name="default_branch" value="{{.default_branch}}" placeholder="{{.default_branch}}">
 							<span class="help">{{ctx.Locale.Tr "repo.default_branch_helper"}}</span>
 						</div>
+						<div class="inline field">
+							<label>{{ctx.Locale.Tr "repo.object_format"}}</label>
+							<div class="ui selection owner dropdown">
+								<input type="hidden" id="object_format_name" name="object_format_name" value="{{.DefaultObjectFormat.Name}}" required>
+								<div class="default text">{{.DefaultObjectFormat.Name}}</div>
+								<div class="menu">
+									{{range .SupportedObjectFormats}}
+										<div class="item" data-value="{{.Name}}">{{.Name}}</div>
+									{{end}}
+								</div>
+							</div>
+							<span class="help">{{ctx.Locale.Tr "repo.object_format_helper"}}</span>
+						</div>
 						<div class="inline field">
 							<label>{{ctx.Locale.Tr "repo.template"}}</label>
 							<div class="ui checkbox">

templates/repo/header.tmpl

@@ -27,6 +27,9 @@
 						<span class="ui basic label">{{ctx.Locale.Tr "repo.desc.template"}}</span>
 						<div class="repo-icon" data-tooltip-content="{{ctx.Locale.Tr "repo.desc.template"}}">{{svg "octicon-repo-template" 18}}</div>
 					{{end}}
+					{{if eq .ObjectFormatName "sha256"}}
+						<span class="ui basic label">{{ctx.Locale.Tr "repo.desc.sha256"}}</span>
+					{{end}}
 				</div>
 			</div>
 			{{if not (or .IsBeingCreated .IsBroken)}}

templates/swagger/v1_json.tmpl

@@ -18370,6 +18370,15 @@
           "uniqueItems": true,
           "x-go-name": "Name"
         },
+        "object_format_name": {
+          "description": "ObjectFormatName of the underlying git repository",
+          "type": "string",
+          "enum": [
+            "sha1",
+            "sha256"
+          ],
+          "x-go-name": "ObjectFormatName"
+        },
         "private": {
           "description": "Whether the repository is private",
           "type": "boolean",
@@ -22185,6 +22194,15 @@
           "type": "string",
           "x-go-name": "Name"
         },
+        "object_format_name": {
+          "description": "ObjectFormatName of the underlying git repository",
+          "type": "string",
+          "enum": [
+            "sha1",
+            "sha256"
+          ],
+          "x-go-name": "ObjectFormatName"
+        },
         "open_issues_count": {
           "type": "integer",
           "format": "int64",