go標準庫的學習-crypto/des

參考：https://studygolang.com/pkgdoc

導入方式：

import "crypto/des"

des包實現了DES標準和TDEA算法，參見U.S. Federal Information Processing Standards Publication 46-3。

Constants 

const BlockSize = 8

DES字節塊的大小。

type KeySizeError

type KeySizeError int

func (KeySizeError) Error

func (k KeySizeError) Error() string

func NewCipher

func NewCipher(key []byte) (cipher.Block, error)

建立並返回一個使用DES算法的cipher.Block接口。

它與的區別在於它的key最長只能爲8字節，不然會報錯,如：

key := []byte("example w")

就會報錯：

panic: crypto/des: invalid key size 9

舉例：

package main

import (
    "fmt"
    "crypto/des"
)

func main() {
    key := []byte("examplew")

    desCipher, err := des.NewCipher(key)
    if err != nil {
        panic(err)
    }
    var inputData = []byte{0x32, 0x43, 0xf6, 0xa8, 0x88, 0x5a, 0x30, 0x8d, 0x31, 0x31, 0x98, 0xa2, 0xe0, 0x37, 0x07, 0x34}
    out := make([]byte, len(inputData))
    desCipher.Encrypt(out, inputData)
    fmt.Printf("Encrypted data : %#v\n", out) //Encrypted data : []byte{0xac, 0x53, 0x6b, 0xbd, 0x59, 0xc5, 0x82, 0x59, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}

    plain := make([]byte, len(inputData))
    desCipher.Decrypt(plain, out)
    fmt.Printf("Decrypted data : %#v\n", plain) //Decrypted data : []byte{0x32, 0x43, 0xf6, 0xa8, 0x88, 0x5a, 0x30, 0x8d, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}
}

 

func NewTripleDESCipher

func NewTripleDESCipher(key []byte) (cipher.Block, error)

建立並返回一個使用TDEA算法的cipher.Block接口。

舉例：

package main

import (
    "fmt"
    "crypto/des"
)

func main() {
    ede2Key := []byte("example key 1234")
    var tripleDESKey []byte
    tripleDESKey = append(tripleDESKey, ede2Key[:16]...)
    tripleDESKey = append(tripleDESKey, ede2Key[:8]...)
    desCipher, err := des.NewTripleDESCipher(tripleDESKey)
    if err != nil {
        panic(err)
    }
    var inputData = []byte{0x32, 0x43, 0xf6, 0xa8, 0x88, 0x5a, 0x30, 0x8d, 0x31, 0x31, 0x98, 0xa2, 0xe0, 0x37, 0x07, 0x34}
    out := make([]byte, len(inputData))
    desCipher.Encrypt(out, inputData)
    fmt.Printf("Encrypted data : %#v\n", out) //Encrypted data : []byte{0x39, 0x9e, 0xbe, 0xa9, 0xc3, 0xfa, 0x77, 0x5e, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}

    plain := make([]byte, len(inputData))
    desCipher.Decrypt(plain, out)
    fmt.Printf("Decrypted data : %#v\n", plain) //Decrypted data : []byte{0x32, 0x43, 0xf6, 0xa8, 0x88, 0x5a, 0x30, 0x8d, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}
}