Move complex crypto logic into a helper package

1 files changed, 85 insertions, 0 deletions

diff --git a/internal/cryptoutil/cryptoutil_test.go b/internal/cryptoutil/cryptoutil_test.go
new file mode 100644
index 0000000..6235878
--- /dev/null
+++ b/internal/cryptoutil/cryptoutil_test.go
@@ -0,0 +1,85 @@
+package cryptoutil
+
+import (
+	"bytes"
+	"encoding/hex"
+	"testing"
+)
+
+func mustHex(t *testing.T, s string) []byte {
+	t.Helper()
+	bytes, err := hex.DecodeString(s)
+	if err != nil {
+		t.Fatalf("Bad hex %q: %s", s, err)
+	}
+	return bytes
+}
+
+func TestPassword(t *testing.T) {
+	const password = "eclair scroll gliding sled shining removed ascend android cheer confetti"
+	hash, err := Hash(password)
+	if err != nil {
+		t.Fatalf("Hash(%q) failed: %s", password, err)
+	}
+	_, err = CheckPassword(password, hash)
+	if err != nil {
+		t.Errorf("CheckPassword(%q, %q) failed: %s", password, hash, err)
+	}
+}
+
+func TestSignature(t *testing.T) {
+	key := HMACKey(mustHex(t, "669e06ec457778b9a8133edb0a87ea82c6b141ffbbc63c038da96258175eb35c"))
+	msg := []byte("test message")
+	signedMsg := key.Sign(msg)
+	got, ok := key.Verify(signedMsg)
+	if !ok {
+		t.Fatalf("Verify(%x) rejected the message", signedMsg)
+	}
+	if !bytes.Equal(got, msg) {
+		t.Errorf("Verify(%x) = %x, want %x", signedMsg, got, msg)
+	}
+}
+
+func TestEncrypt(t *testing.T) {
+	key := EncryptionKey(mustHex(t, "b6de26860e0a39aa134732e58055c06ba028675453f73a6912bc932e58d5743d0e423217f06487d3e96a59980301fcc97dfcc4c6b19765f2947de3c33ab7ef9e"))
+	msg := []byte("test message")
+	encryptedMsg, err := key.Encrypt(msg)
+	if err != nil {
+		t.Fatalf("Encrypt(%q) failed: %s", msg, err)
+	}
+	got, err := key.Decrypt(encryptedMsg)
+	if err != nil {
+		t.Fatalf("Decrypt(%x) failed: %s", encryptedMsg, err)
+	}
+	if !bytes.Equal(got, msg) {
+		t.Errorf("Decrypt(%x) = %x, want %x", encryptedMsg, got, msg)
+	}
+}
+
+func TestDeriveKey(t *testing.T) {
+	const password = "automaker moisture botch tubular kelp rinse rule giggly donated stock"
+	hash, err := Hash(password)
+	if err != nil {
+		t.Fatalf("Hash(%q) failed: %s", password, err)
+	}
+	rawKey, err := CheckPassword(password, hash)
+	if err != nil {
+		t.Fatalf("CheckPassword(%q, %x) failed: %s", password, hash, err)
+	}
+	key, err := rawKey.EncryptionKey()
+	if err != nil {
+		t.Fatalf("EncryptionKey() failed: %s", err)
+	}
+	msg := []byte("test message")
+	encryptedMsg, err := key.Encrypt(msg)
+	if err != nil {
+		t.Fatalf("Encrypt(%q) failed: %s", msg, err)
+	}
+	got, err := key.Decrypt(encryptedMsg)
+	if err != nil {
+		t.Fatalf("Decrypt(%x) failed: %s", encryptedMsg, err)
+	}
+	if !bytes.Equal(got, msg) {
+		t.Errorf("Decrypt(%x) = %x, want %x", encryptedMsg, got, msg)
+	}
+}