feat: add crypto pkg

internal/crypto/bcrypt.go

@@ -0,0 +1,27 @@
+package crypto
+
+import (
+	"golang.org/x/crypto/bcrypt"
+)
+
+var _ HashAlg = (*BCrypt)(nil)
+
+type BCrypt struct {
+	cost int
+}
+
+func NewBCrypt(cost int) *BCrypt {
+	return &BCrypt{cost: cost}
+}
+
+func (b *BCrypt) Algorithm() string {
+	return "bcrypt"
+}
+
+func (b *BCrypt) Hash(value []byte) ([]byte, error) {
+	return bcrypt.GenerateFromPassword(value, b.cost)
+}
+
+func (b *BCrypt) CompareHash(hashed, value []byte) error {
+	return bcrypt.CompareHashAndPassword(hashed, value)
+}