1 files changed, 41 insertions, 0 deletions
diff --git a/player-server/internal/auth/auth.go b/player-server/internal/auth/auth.go
new file mode 100644
index 0000000..55dea94
--- /dev/null
+++ b/player-server/internal/auth/auth.go
@@ -0,0 +1,41 @@
+// Package auth handles authentication and authorization.
+package auth
+
+import (
+	"fmt"
+
+	"golang.org/x/crypto/bcrypt"
+)
+
+// Hasher hashes passwords and compares plaintext against hashes.
+type Hasher interface {
+	Hash(password string) (string, error)
+	Compare(hash, password string) error
+}
+
+// BCryptHasher implements Hasher using bcrypt.
+type BCryptHasher struct {
+	cost int
+}
+
+// NewBCryptHasher creates a BCryptHasher with the given cost.
+func NewBCryptHasher(cost int) *BCryptHasher {
+	return &BCryptHasher{cost: cost}
+}
+
+// Hash returns a bcrypt hash of the password.
+func (b *BCryptHasher) Hash(password string) (string, error) {
+	bytes, err := bcrypt.GenerateFromPassword([]byte(password), b.cost)
+	if err != nil {
+		return "", fmt.Errorf("hash password: %w", err)
+	}
+	return string(bytes), nil
+}
+
+// Compare checks a password against a bcrypt hash.
+func (b *BCryptHasher) Compare(hash, password string) error {
+	return bcrypt.CompareHashAndPassword([]byte(hash), []byte(password))
+}
+
+// Compile-time interface check.
+var _ Hasher = (*BCryptHasher)(nil)