1 files changed, 134 insertions, 0 deletions
diff --git a/object/signed/commit/integration_test.go b/object/signed/commit/integration_test.go
new file mode 100644
index 00000000..2a8d6a4c
--- /dev/null
+++ b/object/signed/commit/integration_test.go
@@ -0,0 +1,134 @@
+package signedcommit_test
+
+import (
+	"bytes"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"testing"
+
+	"codeberg.org/lindenii/furgit/internal/testgit"
+	objectid "codeberg.org/lindenii/furgit/object/id"
+	signedcommit "codeberg.org/lindenii/furgit/object/signed/commit"
+)
+
+func setupSSHSignedCommit(
+	t *testing.T,
+	algo objectid.Algorithm,
+) (payload []byte, allowedSignersPath string, signaturePath string) {
+	t.Helper()
+
+	testRepo := testgit.NewRepo(t, testgit.RepoOptions{ObjectFormat: algo})
+
+	signDir := t.TempDir()
+	signRoot, err := os.OpenRoot(signDir)
+	if err != nil {
+		t.Fatalf("os.OpenRoot(%q): %v", signDir, err)
+	}
+
+	t.Cleanup(func() { _ = signRoot.Close() })
+
+	privateKeyPath := filepath.Join(signDir, "signing_key")
+	allowedSignersPath = filepath.Join(signDir, "allowed_signers")
+	signaturePath = filepath.Join(signDir, "commit.sig")
+
+	cmd := exec.Command( //nolint:noctx
+		"ssh-keygen",
+		"-q",
+		"-t", "ed25519",
+		"-N", "",
+		"-C", "runxiyu@umich.edu",
+		"-f", privateKeyPath,
+	) //#nosec G204
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		t.Fatalf("ssh-keygen generate failed: %v\n%s", err, out)
+	}
+
+	publicKey, err := signRoot.ReadFile("signing_key.pub")
+	if err != nil {
+		t.Fatalf("ReadFile(signing_key.pub): %v", err)
+	}
+
+	err = signRoot.WriteFile(
+		"allowed_signers",
+		append([]byte("runxiyu@umich.edu "), publicKey...),
+		0o600,
+	)
+	if err != nil {
+		t.Fatalf("WriteFile(allowed_signers): %v", err)
+	}
+
+	testRepo.Run(t, "config", "gpg.format", "ssh")
+	testRepo.Run(t, "config", "user.signingkey", privateKeyPath)
+
+	testRepo.WriteFile(t, "file.txt", []byte("signed\n"), 0o644)
+	testRepo.Run(t, "add", "file.txt")
+	testRepo.Run(t, "commit", "-S", "-m", "signed commit")
+
+	commitID := testRepo.RevParse(t, "HEAD^{commit}")
+	body := testRepo.CatFile(t, "commit", commitID)
+
+	commit, err := signedcommit.Parse(body)
+	if err != nil {
+		t.Fatalf("Parse: %v", err)
+	}
+
+	signature, ok := commit.AppendSignature(nil, algo)
+	if !ok {
+		t.Fatalf("missing %s signature", algo)
+	}
+
+	err = signRoot.WriteFile("commit.sig", signature, 0o600)
+	if err != nil {
+		t.Fatalf("WriteFile(commit.sig): %v", err)
+	}
+
+	return commit.AppendPayload(nil), allowedSignersPath, signaturePath
+}
+
+func TestSSHSignedCommitIntegration(t *testing.T) {
+	t.Parallel()
+
+	testgit.ForEachAlgorithm(t, func(t *testing.T, algo objectid.Algorithm) { //nolint:thelper
+		payload, allowedSignersPath, signaturePath := setupSSHSignedCommit(t, algo)
+
+		cmd := exec.Command( //nolint:noctx
+			"ssh-keygen",
+			"-Y", "verify",
+			"-n", "git",
+			"-f", allowedSignersPath,
+			"-I", "runxiyu@umich.edu",
+			"-s", signaturePath,
+		) //#nosec G204
+		cmd.Stdin = bytes.NewReader(payload)
+		out, err := cmd.CombinedOutput()
+		if err != nil {
+			t.Fatalf("ssh-keygen verify failed: %v\n%s", err, out)
+		}
+	})
+}
+
+func TestSSHSignedCommitIntegrationRejectsTamperedPayload(t *testing.T) {
+	t.Parallel()
+
+	testgit.ForEachAlgorithm(t, func(t *testing.T, algo objectid.Algorithm) { //nolint:thelper
+		payload, allowedSignersPath, signaturePath := setupSSHSignedCommit(t, algo)
+		payload = append([]byte(nil), payload...)
+		payload[len(payload)-2] ^= 1
+
+		cmd := exec.Command( //nolint:noctx
+			"ssh-keygen",
+			"-Y", "verify",
+			"-n", "git",
+			"-f", allowedSignersPath,
+			"-I", "runxiyu@umich.edu",
+			"-s", signaturePath,
+		) //#nosec G204
+		cmd.Stdin = bytes.NewReader(payload)
+		out, err := cmd.CombinedOutput()
+		if err == nil {
+			t.Fatalf("ssh-keygen verify unexpectedly succeeded:\n%s", out)
+		}
+	})
+}