68 lines
1.5 KiB
Go
68 lines
1.5 KiB
Go
/*
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Copyright © 2024 Brian Buller <brian@bullercodeworks.com>
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*/
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package util
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import (
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"crypto/aes"
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"crypto/cipher"
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"crypto/rand"
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"encoding/base64"
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"encoding/hex"
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"errors"
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"fmt"
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"io"
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"time"
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)
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func GenTodayKey() string {
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key := []byte(time.Now().Format(fmt.Sprintf("%s%s%s ", time.DateOnly, time.DateOnly, time.DateOnly)))
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return hex.EncodeToString(key) //convert to string for saving
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}
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func Encrypt(key, input string) (string, error) {
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btKey, _ := hex.DecodeString(key)
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plaintext := []byte(input)
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// Create a new Cipher Block from the key
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block, err := aes.NewCipher(btKey)
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if err != nil {
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return "", err
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}
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ciphertext := make([]byte, aes.BlockSize+len(plaintext))
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iv := ciphertext[:aes.BlockSize]
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if _, err := io.ReadFull(rand.Reader, iv); err != nil {
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return "", err
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}
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stream := cipher.NewCFBEncrypter(block, iv)
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stream.XORKeyStream(ciphertext[aes.BlockSize:], plaintext)
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// Convert to base64
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return base64.URLEncoding.EncodeToString(ciphertext), nil
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}
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func Decrypt(key, input string) (string, error) {
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btKey, _ := hex.DecodeString(key)
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ciphertext, _ := base64.URLEncoding.DecodeString(input)
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block, err := aes.NewCipher(btKey)
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if err != nil {
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return "", err
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}
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if len(ciphertext) < aes.BlockSize {
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return "", errors.New("ciphertext is too short")
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}
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iv := ciphertext[:aes.BlockSize]
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ciphertext = ciphertext[aes.BlockSize:]
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stream := cipher.NewCFBDecrypter(block, iv)
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// XORKeyStream can work in-place if the two arguments are the same.
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stream.XORKeyStream(ciphertext, ciphertext)
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return fmt.Sprintf("%s", ciphertext), nil
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}
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