Рыба проекта. Минимальная функциональность

2026-08-03 22:22:24 +03:00
commit 8c8631ac9c
80 changed files with 10618 additions and 0 deletions
@@ -0,0 +1,189 @@
+package x25519
+
+import (
+	"bytes"
+	"crypto/ecdh"
+	"crypto/rand"
+	"crypto/sha256"
+	"errors"
+	"io"
+	"testing"
+)
+
+func TestGenerateKeyPair(t *testing.T) {
+	adapter := New()
+
+	pub, priv, err := adapter.GenerateKeyPair(rand.Reader)
+	if err != nil {
+		t.Fatalf("GenerateKeyPair failed: %v", err)
+	}
+
+	if pub.SchemeID() != suiteID {
+		t.Errorf("pub.SchemeID() = 0x%04x, want 0x%04x", pub.SchemeID(), suiteID)
+	}
+
+	if priv.SchemeID() != suiteID {
+		t.Errorf("priv.SchemeID() = 0x%04x, want 0x%04x", priv.SchemeID(), suiteID)
+	}
+
+	rawPub := pub.Raw()
+	if len(rawPub) != 32 {
+		t.Errorf("pub.Raw() len = %d, want 32", len(rawPub))
+	}
+
+	rawPriv := priv.Raw()
+	if len(rawPriv) != 32 {
+		t.Errorf("priv.Raw() len = %d, want 32", len(rawPriv))
+	}
+
+	expectedKeyID := sha256.Sum256(rawPub)
+	if !bytes.Equal(pub.KeyID(), expectedKeyID[:8]) {
+		t.Errorf("pub.KeyID() = %x, want %x", pub.KeyID(), expectedKeyID[:8])
+	}
+
+	if !bytes.Equal(priv.KeyID(), pub.KeyID()) {
+		t.Errorf("priv.KeyID() = %x, want %x", priv.KeyID(), pub.KeyID())
+	}
+}
+
+func TestEncapsulate(t *testing.T) {
+	adapter := New()
+
+	pub, priv, err := adapter.GenerateKeyPair(rand.Reader)
+	if err != nil {
+		t.Fatalf("GenerateKeyPair failed: %v", err)
+	}
+
+	ct, ss, err := adapter.Encapsulate(pub, rand.Reader)
+	if err != nil {
+		t.Fatalf("Encapsulate failed: %v", err)
+	}
+
+	if len(ct) != 32 {
+		t.Errorf("ciphertext len = %d, want 32", len(ct))
+	}
+
+	if len(ss) != 32 {
+		t.Errorf("sharedSecret len = %d, want 32", len(ss))
+	}
+
+	// Verify ss by independently computing priv.ECDH(ephemeralPubParsedFromCt).
+	ephPub, err := ecdh.X25519().NewPublicKey(ct)
+	if err != nil {
+		t.Fatalf("failed to parse ephemeral public key from ciphertext: %v", err)
+	}
+
+	parsedPriv, err := ecdh.X25519().NewPrivateKey(priv.Raw())
+	if err != nil {
+		t.Fatalf("failed to parse private key: %v", err)
+	}
+
+	computedSS, err := parsedPriv.ECDH(ephPub)
+	if err != nil {
+		t.Fatalf("independent ECDH computation failed: %v", err)
+	}
+
+	if !bytes.Equal(ss, computedSS) {
+		t.Errorf("shared secret mismatch: encapsulate=%x, independent=%x", ss, computedSS)
+	}
+}
+
+func TestRoundTrip(t *testing.T) {
+	adapter := New()
+
+	pub, priv, err := adapter.GenerateKeyPair(rand.Reader)
+	if err != nil {
+		t.Fatalf("GenerateKeyPair failed: %v", err)
+	}
+
+	ct, ssEnc, err := adapter.Encapsulate(pub, rand.Reader)
+	if err != nil {
+		t.Fatalf("Encapsulate failed: %v", err)
+	}
+
+	ssDec, err := adapter.Decapsulate(priv, ct)
+	if err != nil {
+		t.Fatalf("Decapsulate failed: %v", err)
+	}
+
+	if !bytes.Equal(ssEnc, ssDec) {
+		t.Fatalf("shared secret mismatch: encapsulate=%x, decapsulate=%x", ssEnc, ssDec)
+	}
+}
+
+func TestRoundTripMany(t *testing.T) {
+	adapter := New()
+
+	for i := 0; i < 1000; i++ {
+		pub, priv, err := adapter.GenerateKeyPair(rand.Reader)
+		if err != nil {
+			t.Fatalf("iteration %d: GenerateKeyPair failed: %v", i, err)
+		}
+
+		ct, ssEnc, err := adapter.Encapsulate(pub, rand.Reader)
+		if err != nil {
+			t.Fatalf("iteration %d: Encapsulate failed: %v", i, err)
+		}
+
+		ssDec, err := adapter.Decapsulate(priv, ct)
+		if err != nil {
+			t.Fatalf("iteration %d: Decapsulate failed: %v", i, err)
+		}
+
+		if !bytes.Equal(ssEnc, ssDec) {
+			t.Fatalf("iteration %d: shared secret mismatch", i)
+		}
+	}
+}
+
+func TestDecapsulateRandomCiphertext(t *testing.T) {
+	adapter := New()
+
+	_, priv, err := adapter.GenerateKeyPair(rand.Reader)
+	if err != nil {
+		t.Fatalf("GenerateKeyPair failed: %v", err)
+	}
+
+	// Generate a random 32-byte string that is unlikely to be a valid X25519 public key.
+	// Setting the high bit makes it invalid for X25519 (Montgomery u-coordinate must be < 2^255).
+	randomCT := make([]byte, 32)
+	if _, err := io.ReadFull(rand.Reader, randomCT); err != nil {
+		t.Fatalf("failed to read random bytes: %v", err)
+	}
+	randomCT[31] |= 0x80 // set high bit to guarantee invalidity
+
+	_, err = adapter.Decapsulate(priv, randomCT)
+	if err == nil {
+		t.Fatal("Decapsulate with random ciphertext: expected error, got nil")
+	}
+
+	if !errors.Is(err, ErrDecapsulationFailed) {
+		t.Errorf("Decapsulate error = %v, want ErrDecapsulationFailed", err)
+	}
+}
+
+func TestRegistryRegistration(t *testing.T) {
+	factory, err := DefaultRegistry.Lookup(suiteID)
+	if err != nil {
+		t.Fatalf("Lookup suiteID 0x%04x failed: %v", suiteID, err)
+	}
+
+	instance := factory()
+	if instance.SchemeID() != suiteID {
+		t.Errorf("factory() SchemeID = 0x%04x, want 0x%04x", instance.SchemeID(), suiteID)
+	}
+}
+
+func TestFactoryReturnsIndependentInstances(t *testing.T) {
+	factory, err := DefaultRegistry.Lookup(suiteID)
+	if err != nil {
+		t.Fatalf("Lookup suiteID 0x%04x failed: %v", suiteID, err)
+	}
+
+	one := factory()
+	two := factory()
+
+	if one.SchemeID() != two.SchemeID() {
+		t.Error("factory() returned instances with different scheme IDs")
+	}
+}