add generate and hash password

internal/modules/password_generator/generator.go

@@ -0,0 +1,32 @@
+package password_generator
+
+import (
+	"crypto/rand"
+	"math/big"
+)
+
+const (
+	charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
+)
+
+type generator struct {
+	length int
+}
+
+func NewGenerator(length int) IPasswordGenerator {
+	return &generator{
+		length: length,
+	}
+}
+
+func (g *generator) Generate() (string, error) {
+	password := make([]byte, g.length)
+	for i := range password {
+		num, err := rand.Int(rand.Reader, big.NewInt(int64(len(charset))))
+		if err != nil {
+			return "", err
+		}
+		password[i] = charset[num.Int64()]
+	}
+	return string(password), nil
+}

internal/modules/password_generator/interface.go

@@ -0,0 +1,5 @@
+package password_generator
+
+type IPasswordGenerator interface {
+	Generate() (string, error)
+}