From 510f9c21881dcfc4ce02909f8d453c92ac01d918 Mon Sep 17 00:00:00 2001
From: Liam Burnand <liam.burnand@ystv.co.uk>
Date: Sat, 15 Feb 2025 18:05:48 +0000
Subject: [PATCH] Modifying to be more simplistic to use

---
 utils/hash.go | 79 ++++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 63 insertions(+), 16 deletions(-)

diff --git a/utils/hash.go b/utils/hash.go
index e8d7eee..3954aa8 100644
--- a/utils/hash.go
+++ b/utils/hash.go
@@ -3,22 +3,35 @@ package utils
 import (
 	"crypto/rand"
 	"encoding/hex"
+	"errors"
 	"fmt"
 	"math/big"
 
 	whirl "github.com/balacode/zr-whirl"
 )
 
-type Type int
+type (
+	Type       int
+	Length     int
+	Characters string
+)
 
 const (
 	GeneratePassword Type = iota
 	GenerateSalt
+	GenerateUsername
+)
+
+const (
+	UsernameCharacters Characters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
+	SaltCharacters     Characters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789/."
+	PasswordCharacters Characters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!@*()&"
 )
 
 const (
-	saltCharacters     = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789/."
-	passwordCharacters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!@*()&"
+	PasswordLength Length = 12
+	SaltLength     Length = 22
+	UsernameLength Length = 20
 )
 
 // HashPass hashes a password using a Whirlpool hash.
@@ -37,37 +50,71 @@ func HashPass(password string) string {
 	return next
 }
 
+func GenerateRandomLength(length int, randomType Type) (string, error) {
+	if length < 6 || length > 40 {
+		return "", errors.New("length must be between 6 and 40")
+	}
+	switch randomType {
+	case GeneratePassword:
+		b, err := rangeLoop(PasswordCharacters, Length(length))
+		if err != nil {
+			return "", fmt.Errorf("error generating random password: %w", err)
+		}
+
+		return b, nil
+	case GenerateSalt:
+		b, err := rangeLoop(SaltCharacters, Length(length))
+		if err != nil {
+			return "", fmt.Errorf("error generating random salt: %w", err)
+		}
+
+		return "$2a$06$" + b, nil
+	case GenerateUsername:
+		b, err := rangeLoop(UsernameCharacters, Length(length))
+		if err != nil {
+			return "", fmt.Errorf("error generating random username: %w", err)
+		}
+
+		return b, nil
+	default:
+		return "", fmt.Errorf("invalid type: %d", randomType)
+	}
+}
+
 // GenerateRandom generates a random string for either password or salt
 func GenerateRandom(randomType Type) (string, error) {
 	switch randomType {
 	case GeneratePassword:
-		lenPass := big.NewInt(int64(len(passwordCharacters)))
-		passwordLength := 12
-
-		b, err := rangeLoop(lenPass, passwordLength)
+		b, err := rangeLoop(PasswordCharacters, PasswordLength)
 		if err != nil {
-			return "", fmt.Errorf("error generating random: %w", err)
+			return "", fmt.Errorf("error generating random password: %w", err)
 		}
 
 		return b, nil
 	case GenerateSalt:
-		lenSalt := big.NewInt(int64(len(saltCharacters)))
-		saltLength := 22
-
-		b, err := rangeLoop(lenSalt, saltLength)
+		b, err := rangeLoop(SaltCharacters, SaltLength)
 		if err != nil {
-			return "", fmt.Errorf("error generating random: %w", err)
+			return "", fmt.Errorf("error generating random salt: %w", err)
 		}
 
 		return "$2a$06$" + b, nil
+	case GenerateUsername:
+		b, err := rangeLoop(UsernameCharacters, UsernameLength)
+		if err != nil {
+			return "", fmt.Errorf("error generating random username: %w", err)
+		}
+
+		return b, nil
 	default:
 		return "", fmt.Errorf("invalid type: %d", randomType)
 	}
 }
 
 // rangeLoop creates the random string that will be used
-func rangeLoop(length *big.Int, size int) (string, error) {
-	bytes := make([]byte, size)
+func rangeLoop(characters Characters, randomLength Length) (string, error) {
+	bytes := make([]byte, randomLength)
+
+	length := big.NewInt(int64(len(characters)))
 
 	for i := range bytes {
 		randInt, err := rand.Int(rand.Reader, length)
@@ -75,7 +122,7 @@ func rangeLoop(length *big.Int, size int) (string, error) {
 			return "", err
 		}
 
-		bytes[i] = passwordCharacters[randInt.Int64()]
+		bytes[i] = characters[randInt.Int64()]
 	}
 
 	return string(bytes), nil