feat: implement key generation, encryption, and decryption functions with tests

hsp/crypt_test.go

@@ -0,0 +1,93 @@
+package hsp
+
+import (
+	"bytes"
+	"crypto/sha256"
+	"testing"
+)
+
+func TestGenerateAndDerive(t *testing.T) {
+	clientKeys, err := GenerateKeyPair()
+	if err != nil {
+		t.Fatal("ERR: Failed to generate client keys:", err)
+		return
+	}
+
+	serverKeys, err := GenerateKeyPair()
+	if err != nil {
+		t.Fatal("ERR: Failed to generate server keys:", err)
+		return
+	}
+
+	clientShared, err := DeriveSharedKey(clientKeys.Private, serverKeys.Public)
+	if err != nil {
+		t.Fatal("ERR: Failed to generate client shared key:", err)
+		return
+	}
+
+	serverShared, err := DeriveSharedKey(serverKeys.Private, clientKeys.Public)
+	if err != nil {
+		t.Fatal("ERR: Failed to generate server shared key:", err)
+		return
+	}
+
+	clientHash := sha256.Sum256(clientShared[:])
+	serverHash := sha256.Sum256(serverShared[:])
+
+	t.Logf("Client shared key: %x\n", clientHash)
+	t.Logf("Server shared key: %x\n", serverHash)
+
+	// Check they match
+	if clientHash == serverHash {
+		t.Log("🎉 Secure shared key established! 🎉")
+	} else {
+		t.Log("❌ Something went wrong ❌")
+	}
+}
+
+func TestEncryptDecrypt(t *testing.T) {
+	clientKeys, err := GenerateKeyPair()
+	if err != nil {
+		t.Fatal("ERR: Failed to generate client keys:", err)
+		return
+	}
+
+	serverKeys, err := GenerateKeyPair()
+	if err != nil {
+		t.Fatal("ERR: Failed to generate server keys:", err)
+		return
+	}
+
+	clientShared, err := DeriveSharedKey(clientKeys.Private, serverKeys.Public)
+	if err != nil {
+		t.Fatal("ERR: Failed to generate client shared key:", err)
+		return
+	}
+
+	serverShared, err := DeriveSharedKey(serverKeys.Private, clientKeys.Public)
+	if err != nil {
+		t.Fatal("ERR: Failed to generate server shared key:", err)
+		return
+	}
+
+	clientHash := sha256.Sum256(clientShared[:])
+	serverHash := sha256.Sum256(serverShared[:])
+
+	msg := []byte("Hello, World!")
+
+	data, nonce, err := Encrypt(clientHash[:], msg)
+	if err != nil {
+		t.Error("ERR: Failed to encrypt data:", err)
+		return
+	}
+
+	decrypted, err := Decrypt(serverHash[:], nonce, data)
+	if err != nil {
+		t.Error("ERR: Failed to decrypt data:", err)
+		return
+	}
+
+	if !bytes.Equal(msg, decrypted) {
+		t.Error("Plain data doesn't match decrypted one")
+	}
+}