otp generation and encryption added with go

Go/go.mod

@@ -0,0 +1,3 @@
+module one-time-pad-utils
+
+go 1.19

Go/main.go

@@ -0,0 +1,33 @@
+package main
+
+import (
+	"fmt"
+	"flag"
+	"one-time-pad-utils/otp_gen"
+	"one-time-pad-utils/otp_encrypt"
+)
+
+func main(){
+	var genpad = flag.Bool("generate", false, "Generate a new One-Time Pad using CSPRNG")
+	var genpadchunks = flag.Int("chunks", 200, "Specify the amount of chunks to generate")
+	var encryptmessage = flag.String("encrypt", "", "Specify a message you wish to encrypt")
+	var decryptmessage = flag.String("decrypt", "", "Specify a message you wish to decrypt")
+	var otpkey = flag.String("key", "", "The specify required key for encryption and decryption")
+	var _ = encryptmessage
+	var _ = decryptmessage
+	var _ = otpkey
+
+	flag.Parse()
+
+	if *genpad {
+		fmt.Printf("%v\n", otpgen.GenerateOTP(*genpadchunks))
+		return
+	}
+
+	if *encryptmessage != "" {
+		fmt.Printf("%v\n", otpencrypt.OTPEncrypt(*encryptmessage,*otpkey))
+		return
+	}
+	
+	flag.PrintDefaults()
+}

Go/otp_encrypt/otp_encrypt.go

@@ -0,0 +1,51 @@
+package otpencrypt
+
+import (
+	"strings"
+	"one-time-pad-utils/pad_definitions"
+)
+
+func OTPEncrypt(message string, key string) string {
+	message = strings.Replace(message, " ", "", -1)
+	messagesplit := strings.Split(message,"")
+	var messagesplitint []int
+
+	key = strings.Replace(key, " ", "", -1)
+	keysplit := strings.Split(key,"")
+	var keysplitint []int
+
+	for _, char := range messagesplit {
+		for n, c := range paddefinitions.NumToCharMap{
+			if c == strings.ToUpper(char) {
+				messagesplitint = append(messagesplitint, n)
+			
+			}
+		}
+	}
+	
+	for _, char := range keysplit {
+		for n, c := range paddefinitions.NumToCharMap{
+			if c == strings.ToUpper(char) {
+				keysplitint = append(keysplitint, n)
+			
+			}
+		}
+	}
+
+	if len(keysplitint) < len(messagesplitint) {
+		return ("KEY TOO SHORT TO ENCRYPT MESSAGE")
+	}
+
+	var encryptedmessage []string
+
+	for pos, messagenum := range messagesplitint{
+		encryptedmessage = append(encryptedmessage, paddefinitions.NumToCharMap[(messagenum + keysplitint[pos]) % 35])
+
+	}
+
+
+
+	return (strings.Join(encryptedmessage, ""))
+
+
+}

Go/otp_gen/otp_gen.go

@@ -0,0 +1,33 @@
+//One-Time Pad generator
+
+package otpgen
+
+import (
+	"crypto/rand"
+	"math/big"
+	"one-time-pad-utils/pad_definitions"
+)
+
+
+func GenerateOTP(chunks int) string {
+	count := 1
+	otpstring := ""
+
+	for count < (chunks*5)+1{
+		n, err := rand.Int(rand.Reader, big.NewInt(36)) // generate new cryptographically secure random number
+		if err != nil {
+			panic(err)
+		}
+		otpstring += paddefinitions.NumToCharMap[int(n.Int64())] // print that number using the character map
+		if count % 5 == 0 { // add a space every 5 characters, newline after 10 chunks
+			if count % 50 == 0{
+				otpstring += "\n"
+			} else {
+				otpstring += " "
+			}
+		}
+		count+=1
+	}
+
+	return otpstring
+}

Go/pad_definitions/pad_definitions.go

@@ -0,0 +1,40 @@
+package paddefinitions
+
+var NumToCharMap = map[int]string{
+	0: "9",
+	1: "A",
+	2: "B",
+	3: "C",
+	4: "D",
+	5: "E",
+	6: "F",
+	7: "G",
+	8: "H",
+	9: "I",
+	10: "J",
+	11: "K",
+	12: "L",
+	13: "M",
+	14: "N",
+	15: "O",
+	16: "P",
+	17: "Q",
+	18: "R",
+	19: "S",
+	20: "T",
+	21: "U",
+	22: "V",
+	23: "W",
+	24: "X",
+	25: "Y",
+	26: "Z",
+	27: "0",
+	28: "1",
+	29: "2",
+	30: "3",
+	31: "4",
+	32: "5",
+	33: "6",
+	34: "7",
+	35: "8",
+}