1 files changed, 156 insertions, 0 deletions
diff --git a/internal/cryptokit/cryptokit_test.go b/internal/cryptokit/cryptokit_test.go
new file mode 100644
index 0000000..928120e
--- /dev/null
+++ b/internal/cryptokit/cryptokit_test.go
@@ -0,0 +1,156 @@
+package cryptokit
+
+import (
+	"bytes"
+	"crypto/ed25519"
+	"crypto/rand"
+	"crypto/rsa"
+	"encoding/base64"
+	"encoding/pem"
+	"os"
+	"os/exec"
+	"testing"
+
+	"filippo.io/age"
+	"golang.org/x/crypto/ssh"
+)
+
+func TestEd25519SignVerifyAcceptsSeedEncoding(t *testing.T) {
+	public, private, err := ed25519.GenerateKey(rand.Reader)
+	if err != nil {
+		t.Fatal(err)
+	}
+	message := []byte("Aegis cryptographic test")
+	signature, err := SignEd25519(message, base64.StdEncoding.EncodeToString(private.Seed()))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := VerifyEd25519(message, signature, base64.StdEncoding.EncodeToString(public)); err != nil {
+		t.Fatal(err)
+	}
+	if err := VerifyEd25519([]byte("tampered"), signature, base64.StdEncoding.EncodeToString(public)); err == nil {
+		t.Fatal("tampered message verified")
+	}
+}
+
+func TestEd25519PublicKeyAndFingerprint(t *testing.T) {
+	public, private, err := ed25519.GenerateKey(rand.Reader)
+	if err != nil {
+		t.Fatal(err)
+	}
+	derived, err := Ed25519PublicKey(base64.StdEncoding.EncodeToString(private.Seed()))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if derived != base64.StdEncoding.EncodeToString(public) {
+		t.Fatalf("derived public key = %q, want %q", derived, base64.StdEncoding.EncodeToString(public))
+	}
+	fingerprint, err := Ed25519PublicKeyFingerprint(derived)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(fingerprint) != len("sha256:")+64 || fingerprint[:len("sha256:")] != "sha256:" {
+		t.Fatalf("unexpected fingerprint %q", fingerprint)
+	}
+}
+
+func TestAgeRoundTrip(t *testing.T) {
+	identity, err := age.GenerateX25519Identity()
+	if err != nil {
+		t.Fatal(err)
+	}
+	ciphertext, err := EncryptAge([]byte("age test"), identity.Recipient().String())
+	if err != nil {
+		t.Fatal(err)
+	}
+	plaintext, err := DecryptAge(ciphertext, identity.String())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if string(plaintext) != "age test" {
+		t.Fatalf("unexpected plaintext %q", plaintext)
+	}
+}
+
+func TestAgeSSHCompatibility(t *testing.T) {
+	testKey := func(private any) {
+		signer, err := ssh.NewSignerFromKey(private)
+		if err != nil {
+			t.Fatal(err)
+		}
+		privatePEM, err := ssh.MarshalPrivateKey(private, "")
+		if err != nil {
+			t.Fatal(err)
+		}
+		ciphertext, err := EncryptAge([]byte("age SSH test"), string(ssh.MarshalAuthorizedKey(signer.PublicKey())))
+		if err != nil {
+			t.Fatal(err)
+		}
+		plaintext, err := DecryptAge(ciphertext, string(pem.EncodeToMemory(privatePEM)))
+		if err != nil {
+			t.Fatal(err)
+		}
+		if string(plaintext) != "age SSH test" {
+			t.Fatalf("unexpected plaintext %q", plaintext)
+		}
+	}
+	_, edPrivate, err := ed25519.GenerateKey(rand.Reader)
+	if err != nil {
+		t.Fatal(err)
+	}
+	testKey(edPrivate)
+	rsaPrivate, err := rsa.GenerateKey(rand.Reader, 2048)
+	if err != nil {
+		t.Fatal(err)
+	}
+	testKey(rsaPrivate)
+}
+
+func TestOpenPGPRoundTripWithUserKeyMaterial(t *testing.T) {
+	gpg, err := exec.LookPath("gpg")
+	if err != nil {
+		t.Skip("gpg is not installed")
+	}
+	home := t.TempDir()
+	if err := os.Chmod(home, 0o700); err != nil {
+		t.Fatal(err)
+	}
+	run := func(args []string, input []byte) ([]byte, error) {
+		cmd := exec.Command(gpg, append([]string{"--batch", "--no-tty", "--no-options", "--homedir", home}, args...)...)
+		cmd.Stdin = bytes.NewReader(input)
+		return cmd.Output()
+	}
+	if _, err := run([]string{"--pinentry-mode", "loopback", "--passphrase", "", "--quick-generate-key", "Aegis Test <aegis@example.invalid>", "rsa2048", "sign", "1d"}, nil); err != nil {
+		t.Skipf("gpg cannot create an ephemeral test key: %v", err)
+	}
+	if _, err := run([]string{"--pinentry-mode", "loopback", "--passphrase", "", "--quick-add-key", "aegis@example.invalid", "rsa2048", "encrypt", "1d"}, nil); err != nil {
+		t.Skipf("gpg cannot create an ephemeral encryption subkey: %v", err)
+	}
+	publicKey, err := run([]string{"--armor", "--export", "aegis@example.invalid"}, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	privateKey, err := run([]string{"--armor", "--export-secret-keys", "aegis@example.invalid"}, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	message := []byte("OpenPGP compatibility test")
+	signature, err := SignOpenPGPDetached(message, string(privateKey))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := VerifyOpenPGPDetached(message, signature, string(publicKey)); err != nil {
+		t.Fatal(err)
+	}
+	ciphertext, err := EncryptOpenPGP(message, string(publicKey), string(privateKey))
+	if err != nil {
+		t.Fatal(err)
+	}
+	plaintext, err := DecryptOpenPGP([]byte(ciphertext), string(privateKey))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if string(plaintext) != string(message) {
+		t.Fatalf("unexpected plaintext %q", plaintext)
+	}
+}