1 files changed, 49 insertions, 0 deletions
diff --git a/cmd/gitaly-git2go/git2goutil/test_sign.go b/cmd/gitaly-git2go/git2goutil/test_sign.go
new file mode 100644
index 000000000..990344910
--- /dev/null
+++ b/cmd/gitaly-git2go/git2goutil/test_sign.go
@@ -0,0 +1,49 @@
+//go:build gitaly_test_signing
+
+package git2goutil
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"strings"
+	"time"
+
+	"github.com/ProtonMail/go-crypto/openpgp"
+	"github.com/ProtonMail/go-crypto/openpgp/packet"
+)
+
+// CreateCommitSignature reads the given signing key and produces PKCS#7 detached signature.
+// When the path to the signing key is not present, an empty signature is returned.
+// Test version creates deterministic signature which is the same with the same data every run.
+func CreateCommitSignature(signingKeyPath, contentToSign string) (string, error) {
+	if signingKeyPath == "" {
+		return "", nil
+	}
+
+	file, err := os.Open(signingKeyPath)
+	if err != nil {
+		return "", fmt.Errorf("open file: %w", err)
+	}
+
+	entity, err := openpgp.ReadEntity(packet.NewReader(file))
+	if err != nil {
+		return "", fmt.Errorf("read entity: %w", err)
+	}
+
+	sigBuf := new(bytes.Buffer)
+	if err := openpgp.ArmoredDetachSignText(
+		sigBuf,
+		entity,
+		strings.NewReader(contentToSign),
+		&packet.Config{
+			Time: func() time.Time {
+				return time.Date(2022, 8, 20, 11, 22, 33, 0, time.UTC)
+			},
+		},
+	); err != nil {
+		return "", fmt.Errorf("sign commit: %w", err)
+	}
+
+	return sigBuf.String(), nil
+}