initial commit

backend/internal/security/security.go

@@ -0,0 +1,75 @@
+package security
+
+import (
+	"errors"
+	"fmt"
+	"time"
+
+	"github.com/golang-jwt/jwt/v5"
+	"golang.org/x/crypto/bcrypt"
+)
+
+var ErrInvalidToken = errors.New("invalid token")
+
+type Claims struct {
+	UserID uint   `json:"userId"`
+	Email  string `json:"email"`
+	Role   string `json:"role"`
+	jwt.RegisteredClaims
+}
+
+type ITokenManager interface {
+	Issue(uint, string, string) (string, error)
+	Parse(string) (Claims, error)
+}
+
+type TokenManager struct {
+	secret []byte
+	ttl    time.Duration
+	now    func() time.Time
+}
+
+func NewTokenManager(secret string, ttl time.Duration) *TokenManager {
+	return &TokenManager{secret: []byte(secret), ttl: ttl, now: time.Now}
+}
+
+func (m *TokenManager) Issue(userID uint, email, role string) (string, error) {
+	now := m.now()
+	claims := Claims{
+		UserID: userID, Email: email, Role: role,
+		RegisteredClaims: jwt.RegisteredClaims{
+			Subject: fmt.Sprint(userID), IssuedAt: jwt.NewNumericDate(now),
+			ExpiresAt: jwt.NewNumericDate(now.Add(m.ttl)),
+		},
+	}
+	return jwt.NewWithClaims(jwt.SigningMethodHS256, claims).SignedString(m.secret)
+}
+
+func (m *TokenManager) Parse(raw string) (Claims, error) {
+	token, err := jwt.ParseWithClaims(raw, &Claims{}, func(token *jwt.Token) (any, error) {
+		if token.Method != jwt.SigningMethodHS256 {
+			return nil, ErrInvalidToken
+		}
+		return m.secret, nil
+	})
+	if err != nil || !token.Valid {
+		return Claims{}, ErrInvalidToken
+	}
+	claims, ok := token.Claims.(*Claims)
+	if !ok {
+		return Claims{}, ErrInvalidToken
+	}
+	return *claims, nil
+}
+
+func HashPassword(password string) (string, error) {
+	value, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
+	if err != nil {
+		return "", fmt.Errorf("hash password: %w", err)
+	}
+	return string(value), nil
+}
+
+func CheckPassword(hash, password string) bool {
+	return bcrypt.CompareHashAndPassword([]byte(hash), []byte(password)) == nil
+}

backend/internal/security/security_test.go

@@ -0,0 +1,33 @@
+package security
+
+import (
+	"testing"
+	"time"
+)
+
+func TestTokenRoundTrip(t *testing.T) {
+	manager := NewTokenManager("01234567890123456789012345678901", time.Hour)
+	raw, err := manager.Issue(42, "interviewer@example.com", "interviewer")
+	if err != nil {
+		t.Fatal(err)
+	}
+	claims, err := manager.Parse(raw)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if claims.UserID != 42 || claims.Email != "interviewer@example.com" || claims.Role != "interviewer" {
+		t.Fatalf("unexpected claims: %#v", claims)
+	}
+}
+
+func TestRejectsTokenSignedWithAnotherSecret(t *testing.T) {
+	issuer := NewTokenManager("01234567890123456789012345678901", time.Hour)
+	verifier := NewTokenManager("abcdefghijklmnopqrstuvwxyz123456", time.Hour)
+	raw, err := issuer.Issue(1, "user@example.com", "interviewer")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := verifier.Parse(raw); err == nil {
+		t.Fatal("expected token validation to fail")
+	}
+}