func main() {
encoded := util.ReadFile("10.txt")
src, _ := base64.StdEncoding.DecodeString(string(encoded))
key := []byte("YELLOW SUBMARINE")
iv := make([]byte, 16)
block, _ := aes.NewCipher(key)
util.CBCDecrypt(block, iv, src, src)
util.CBCEncrypt(block, iv, src, src)
util.CBCDecrypt(block, iv, src, src)
fmt.Println(string(src))
}
func isAdmin(ct []byte) bool {
block, _ := aes.NewCipher(key)
res := make([]byte, len(ct))
copy(res, ct)
util.CBCDecrypt(block, iv, res, res)
fmt.Println("isAdmin peek:", string(res))
return bytes.Count(res, []byte(";admin=true;")) > 0
}
func isPadValid(ct, iv []byte) bool {
block, _ := aes.NewCipher(key)
res := make([]byte, len(ct))
copy(res, ct)
util.CBCDecrypt(block, iv, res, res)
_, err := util.CheckPadding(res)
// fmt.Println(res, err == nil)
return err == nil
}
func aesDecrypt(s *big.Int, ct, iv []byte) (t []byte) {
sum := sha1.Sum([]byte(s.String()))
blockA, _ := aes.NewCipher(sum[0:16])
tPadded := make([]byte, len(ct))
util.CBCDecrypt(blockA, iv, tPadded, ct)
t, err := util.CheckPadding(tPadded)
if err != nil {
log.Fatal(err, tPadded)
}
return
}
func decrypt(ct []byte) ([]byte, error) {
block, _ := aes.NewCipher(key)
res := make([]byte, len(ct))
util.CBCDecrypt(block, key, res, ct)
for i := 0; i < len(res); i++ {
if res[i] > 127 {
return nil, errors.New("Wrong text: " + string(res))
}
}
return res, nil
}
