Add a migration to remove SSH signatures from release notes

Because the `git` module did not recognize SSH signed tags, those
signatures ended up in the `notes` column of the `release` table. While
future signatures will not end up there, Forgejo should clean up the old
ones.

This migration does just that: finds all releases that have an SSH
signature, and removes those signatures, preserving the rest of the
note (if any).

While this may seem like an expensive operation, it's only done once,
and even on the largest known Forgejo instance as of this
writing (Codeberg), the number of affected rows are just over a hundred,
a tiny amount all things considered.

Signed-off-by: Gergely Nagy <forgejo@gergo.csillger.hu>

models/forgejo_migrations/migrate.go

@@ -52,6 +52,8 @@ var migrations = []*Migration{
 	NewMigration("Add wiki_branch to repository", forgejo_v1_22.AddWikiBranchToRepository),
 	// v6 -> v7
 	NewMigration("Add enable_repo_unit_hints to the user table", forgejo_v1_22.AddUserRepoUnitHintsSetting),
+	// v7 -> v8
+	NewMigration("Remove SSH signatures from Release notes", forgejo_v1_22.RemoveSSHSignaturesFromReleaseNotes),
 }
 
 // GetCurrentDBVersion returns the current Forgejo database version.

models/forgejo_migrations/v1_22/main_test.go

@@ -0,0 +1,14 @@
+// Copyright 2024 The Forgejo Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package v1_22 //nolint
+
+import (
+	"testing"
+
+	"code.gitea.io/gitea/models/migrations/base"
+)
+
+func TestMain(m *testing.M) {
+	base.MainTest(m)
+}

models/forgejo_migrations/v1_22/v8.go

@@ -0,0 +1,51 @@
+// Copyright 2024 The Forgejo Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package v1_22 //nolint
+
+import (
+	"strings"
+
+	"xorm.io/xorm"
+)
+
+func RemoveSSHSignaturesFromReleaseNotes(x *xorm.Engine) error {
+	type Release struct {
+		ID   int64  `xorm:"pk autoincr"`
+		Note string `xorm:"TEXT"`
+	}
+
+	if err := x.Sync(&Release{}); err != nil {
+		return err
+	}
+
+	var releaseNotes []struct {
+		ID   int64
+		Note string
+	}
+
+	if err := x.Table("release").Where("note LIKE '%-----BEGIN SSH SIGNATURE-----%'").Find(&releaseNotes); err != nil {
+		return err
+	}
+
+	sess := x.NewSession()
+	defer sess.Close()
+
+	if err := sess.Begin(); err != nil {
+		return err
+	}
+
+	for _, release := range releaseNotes {
+		idx := strings.LastIndex(release.Note, "-----BEGIN SSH SIGNATURE-----")
+		if idx == -1 {
+			continue
+		}
+		release.Note = release.Note[:idx]
+		_, err := sess.Exec("UPDATE `release` SET note = ? WHERE id = ?", release.Note, release.ID)
+		if err != nil {
+			return err
+		}
+	}
+
+	return sess.Commit()
+}

models/forgejo_migrations/v1_22/v8_test.go

@@ -0,0 +1,34 @@
+// Copyright 2024 The Forgejo 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"
+)
+
+func Test_RemoveSSHSignaturesFromReleaseNotes(t *testing.T) {
+	// A reduced mock of the `repo_model.Release` struct.
+	type Release struct {
+		ID   int64  `xorm:"pk autoincr"`
+		Note string `xorm:"TEXT"`
+	}
+
+	x, deferable := base.PrepareTestEnv(t, 0, new(Release))
+	defer deferable()
+
+	assert.NoError(t, RemoveSSHSignaturesFromReleaseNotes(x))
+
+	var releases []Release
+	err := x.Table("release").OrderBy("id ASC").Find(&releases)
+	assert.NoError(t, err)
+	assert.Len(t, releases, 3)
+
+	assert.Equal(t, "", releases[0].Note)
+	assert.Equal(t, "A message.\n", releases[1].Note)
+	assert.Equal(t, "no signature present here", releases[2].Note)
+}

models/migrations/fixtures/Test_RemoveSSHSignaturesFromReleaseNotes/release.yml

@@ -0,0 +1,22 @@
+# type Release struct {
+#   ID   int64  `xorm:"pk autoincr"`
+#   Note string `xorm:"TEXT"`
+# }
+-
+  id: 1
+  note: |
+    -----BEGIN SSH SIGNATURE-----
+    some signature
+    -----END SSH SIGNATURE-----
+
+-
+  id: 2
+  note: |
+    A message.
+    -----BEGIN SSH SIGNATURE-----
+    some signature
+    -----END SSH SIGNATURE-----
+
+-
+  id: 3
+  note: "no signature present here"