代码非常长 有六百多行
参考一位博主的理论实现
通俗易懂，十分钟读懂DES
还有很多不足的地方
感觉只是个思路
S盒（理论既定）
package src// 定义S - 盒的置换表
var SBoxes = [8][4][16]int{{{14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7},{0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8},{4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0},{15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13},},{{15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10},{3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5},{0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15},{13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9},},{{10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8},{13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1},{13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7},{1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12},},{{7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15},{13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9},{10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4},{3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14},},{{2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9},{14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6},{4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14},{11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3},},{{12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11},{10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8},{9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6},{4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13},},{{4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1},{13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6},{1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2},{6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12},},{{13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7},{1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2},{7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8},{2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11},},
}
主代码
可以适应各种输入
但是时间有限没能调通
位运算真的折磨人（悲
package mainimport ("bufio""crypto/rand""encoding/binary""fmt""main/src""os""strings"
)// 如果不足六十四位密钥 进行随机填充
func PadKeyWithRandom(key []byte) []byte {// 输出原始密钥长度fmt.Println("原始密钥长度：", len(key))// 计算需要填充的字节数padLen := 8 - len(key)// 创建一个新的字节切片，长度为64位 8字节newKey := make([]byte, 8)// 复制原始密钥到新密钥的开头copy(newKey, key)// 生成随机字节填充剩余字节randomBytes := make([]byte, padLen)_, err := rand.Read(randomBytes)if err != nil {panic(err)}// 将随机字节添加到密钥for i := len(key); i < 8; i++ {newKey[i] = randomBytes[i-len(key)]}// 输出填充后的密钥长度fmt.Println("填充后的密钥长度：", len(newKey))return newKey
}// 如果明文不足64位bit 就填充
func PadPlaintext(plaintext []byte) []byte {for len(plaintext) < 8 {plaintext = append(plaintext, 0x00)}return plaintext
}// 初始置换 最开始
func InitialPermutation(text []byte) []byte {if len(text) != 8 {panic("Invalid len of 64 bits for Init")}var piece = [][]int{{58, 50, 42, 34, 26, 18, 10, 2},{60, 52, 44, 36, 28, 20, 12, 4},{62, 54, 46, 38, 30, 22, 14, 6},{64, 56, 48, 40, 32, 24, 16, 8},{57, 49, 41, 33, 25, 17, 9, 1},{59, 51, 43, 35, 27, 19, 11, 3},{61, 53, 45, 37, 29, 21, 13, 5},{63, 55, 47, 39, 31, 23, 15, 7},}result := make([]byte, 8)for i := 0; i < len(piece); i++ {for j := 0; j < 8; j++ {index := piece[i][j] - 1// 确定该比特位所在的字节在整个密钥字节切片中的某个字节索引byteIndex := index / 8// 在当前字节内，要处理的比特位相对于字节最高位（第 7 位）的偏移量 就是先确定某个字节再瞬移到要取的比特位bitOffset := 7 - (index % 8)// 分前后四字节的两段// key[bitIndex/8]就是简单的选定要找的字节// (1 << (7 - (bitIndex % 8)))作用是挪动1去某个位置，通过与操作来提取出原始字节中我们想要的那个比特位// 然后开始为放入c0服务// 将前面提取出的比特位再向右移动 7 - (bitIndex % 8) 位，这一步的目的是将提取出的比特位调整到最低位// 最后将调整到最低位的比特位再向左移动 bitOffset 位，这样就可以将该比特位设置到 c0 中相应字节的正确位置上result[byteIndex] |= (text[index/8] & (1 << (7 - (index % 8)))) >> (7 - (index % 8)) << bitOffset}}fmt.Printf("明文/密文 初始置换结果：%v\n", result)return result
}// 逆置换 最后
func ReversePermutation(text []byte) []byte {if len(text) != 8 {panic("Invalid len of 64 bits for Reverse")}var piece = [][]int{{40, 8, 48, 16, 56, 24, 64, 32},{39, 7, 47, 15, 55, 23, 63, 31},{38, 6, 46, 14, 54, 22, 62, 30},{37, 5, 45, 13, 53, 21, 61, 29},{36, 4, 44, 12, 52, 20, 60, 28},{35, 3, 43, 11, 51, 19, 59, 27},{34, 2, 42, 10, 50, 18, 58, 26},{33, 1, 41, 9, 49, 17, 57, 25},}result := make([]byte, 8)for i := 0; i < len(piece); i++ {for j := 0; j < 8; j++ {index := piece[i][j] - 1// 确定该比特位所在的字节在整个密钥字节切片中的某个字节索引byteIndex := index / 8// 在当前字节内，要处理的比特位相对于字节最高位（第 7 位）的偏移量 就是先确定某个字节再瞬移到要取的比特位bitOffset := 7 - (index % 8)result[byteIndex] |= (text[index/8] & (1 << (7 - (index % 8)))) >> (7 - (index % 8)) << bitOffset}}return result
}// 拆开得L0和R0
func SplitLR(text []byte) ([]byte, []byte) {if len(text) != 8 {panic("Invalid SplitLR of 64 bits")}left := text[0:4]right := text[4:8]return left, right
}// 拼起来L16和R16
func MergeLR(left, right []byte) []byte {if len(left) != 4 || len(right) != 4 {panic("Invalid left or right for MergeLR 64 bits size")}text := make([]byte, 8)copy(text[0:4], left)copy(text[4:8], right)return text
}/*
// 每个加密轮应该包括扩展、生成每轮子密钥、进行异或、S盒、P盒
func Encrypt(L, R []byte) ([]byte, []byte) {Expand32To48(R)
}
*/// 1. 扩展32->48
func Expand32To48(input []byte) []byte {if len(input) != 4 {panic("Invalid len of 32bits(4 bytes) for Expand32To48")}// 置换表permutationTable := [][]int{{32, 1, 2, 3, 4, 5},{4, 5, 6, 7, 8, 9},{8, 9, 10, 11, 12, 13},{12, 13, 14, 15, 16, 17},{16, 17, 18, 19, 20, 21},{20, 21, 22, 23, 24, 25},{24, 25, 26, 27, 28, 29},{28, 29, 30, 31, 32, 1},}result := make([]byte, 6)var bitcount = 0 //用于统计result的比特位置var bittarget = 0 //统计result放入的具体偏移量for row := 0; row < len(permutationTable); row++ {for col := 0; col < len(permutationTable[row]); col++ {index := permutationTable[row][col] - 1bittarget = bitcount % 8result[bitcount/8] = input[index/8] & (1 << (7 - (index % 8))) >> (7 - (index % 8)) << bittargetbitcount++}}return result
}// 2. 生成子密钥
// 密钥调度算法可以将64位的主密钥分成16个子密钥，每个子密钥48位，用于每轮加密中与输入数据进行异或运算。
func GenerateSubkey(key []byte) [][]byte {// 置换选择1C0, D0 := PC1Permutation(key)var subkeys [][]bytefor i := 1; i <= 16; i++ {c := CircularLeftShift(C0, i)d := CircularLeftShift(D0, i)subkey := PC2Permutation(c, d)subkeys = append(subkeys, subkey)// 详细打印当前生成的子密钥内容fmt.Printf("生成第 %d 个 子密钥：\n", i)fmt.Printf("子密钥内容（十六进制）：")for _, b := range subkey {fmt.Printf("%02x ", b)}fmt.Println()// 更新左移结果 一共十六轮C0 = cD0 = d}fmt.Println()return subkeys}// 2.1 实现PC - 1置换操作
func PC1Permutation(key []byte) ([]byte, []byte) {if len(key) != 8 {panic("Invalid key length for PC1Permutation. Expected 8 bytes (64 bits).")}pc1Table := [][]int{{57, 49, 41, 33, 25, 17, 9, 1, 58, 50, 42, 34, 26, 18},{10, 2, 59, 51, 43, 35, 27, 19, 11, 3, 60, 52, 44, 36},{63, 55, 47, 39, 31, 23, 15, 7, 62, 54, 46, 38, 30, 22},{14, 6, 61, 53, 45, 37, 29, 21, 13, 5, 28, 20, 12, 4},}c0 := make([]byte, 4)d0 := make([]byte, 4)for i := 0; i < len(pc1Table); i++ {for j := 0; j < len(pc1Table[i]); j++ {// 要处理原始密钥中的第 pc表值-1 个比特位bitIndex := pc1Table[i][j] - 1// 确定该比特位所在的字节在整个密钥字节切片中的某个字节索引byteIndex := bitIndex / 8// 在当前字节内，要处理的比特位相对于字节最高位（第 7 位）的偏移量 就是先确定某个字节再瞬移到要取的比特位bitOffset := 7 - (bitIndex % 8)// 分前后四字节的两段if byteIndex < 4 {// key[bitIndex/8]就是简单的选定要找的字节// (1 << (7 - (bitIndex % 8)))作用是挪动1去某个位置，通过与操作来提取出原始字节中我们想要的那个比特位// 然后开始为放入c0服务// 将前面提取出的比特位再向右移动 7 - (bitIndex % 8) 位，这一步的目的是将提取出的比特位调整到最低位// 最后将调整到最低位的比特位再向左移动 bitOffset 位，这样就可以将该比特位设置到 c0 中相应字节的正确位置上c0[byteIndex] |= (key[bitIndex/8] & (1 << (7 - (bitIndex % 8)))) >> (7 - (bitIndex % 8)) << bitOffset// 输出提取后比特位在c0中的位置//fmt.Printf("提取后比特位在c0中的位置: %d\n", byteIndex)// 输出c0的当前状态//fmt.Printf("c0当前状态: %v\n", c0)} else {// 减去 4，因为 d0 是从原始密钥经过处理后得到的后半部分 其他类同d0[byteIndex-4] |= (key[bitIndex/8] & (1 << (7 - (bitIndex % 8)))) >> (7 - (bitIndex % 8)) << bitOffset}}}fmt.Println("PC-1置换结果如下：")fmt.Println("c0 length:", len(c0))fmt.Println("c0 content:", c0)fmt.Println("d0 length:", len(d0))fmt.Println("d0 content:", d0)return c0, d0}// 2.2 循环左移操作
func CircularLeftShift(data []byte, times int) []byte {num := binary.BigEndian.Uint32(data)// 将uint32转换为二进制字符串binaryStr := fmt.Sprintf("%032b", num)fmt.Printf("num的二进制表示: %s\n", binaryStr)result := make([]byte, 4)if times > 16 || times < 1 {panic("ShiftLeft Error")}var shiftTable = [16]int{1, 1, 2, 2, 2, 2, 2, 2,1, 2, 2, 2, 2, 2, 2, 1,}// 由于在数值中，高位在左，低位在右，所以采用右移，在大端模式下是左移var out uint32 = numfor i := 0; i < shiftTable[times-1]; i++ {// 获取最低位h := num & 1//fmt.Printf("h:%d\n", h)outStr := fmt.Sprintf("%032b", out)fmt.Printf("out之前的二进制表示: %s\n", outStr)// 先将out整体左移一位out <<= 1// 当h为0时，进行特殊处理将num的最高位补到out的最低位if h == 0 {// 获取num的最高位highestBit := num >> 31// 将num的最高位补到out的最低位out |= highestBit} else {// 当h不为0时，直接将h补到out的最低位out |= h}outStr = fmt.Sprintf("%032b", out)fmt.Printf("out左移1次后的二进制表示: %s\n", outStr)// 同时对num也进行类似的左移操作，保持数据状态的一致性num <<= 1// 如果num超过了uint32的范围，进行处理（比如截断等，这里简单示例截断）if num > (1<<32 - 1) {num &= (1<<32 - 1)}}binary.BigEndian.PutUint32(result, out)// 将uint32转换为二进制字符串resStr := fmt.Sprintf("%08b", result)fmt.Printf("result的二进制表示: %s\n", resStr)return result
}// 2.3 PC-2置换
func PC2Permutation(c []byte, d []byte) []byte {// totalBits := 56// 这里totalBits应该是56，因为c0和d0都是4字节（32位），拼接起来就是56位// fmt.Printf("totalbits:%d\n", totalBits)// 不含奇偶校验位第 8、16、24、32、40、48、56位pc2Table := [][]int{{14, 17, 11, 24, 1, 5},{3, 28, 15, 6, 21, 10},{23, 19, 12, 4, 26, 8},{16, 7, 27, 20, 13, 2},{41, 52, 31, 37, 47, 55},{30, 40, 51, 45, 33, 48},{44, 49, 39, 56, 34, 53},{46, 42, 50, 36, 29, 32},}result := make([]byte, 6)// 将切片 d 中的所有元素逐个添加到切片 c 的末尾，然后返回一个新的切片combined := append(c, d...)fmt.Println("combined: ", combined)var bitcount = 0 //用于统计result的比特位置var bittarget = 0 //统计result放入的具体偏移量for i := 0; i < 8; i++ {for j := 0; j < 6; j++ {// 获取 表值-1 的真正的索引去cd合体的里面找bitIndex := pc2Table[i][j] - 1// 获取字节的索引byteIndex := bitIndex / 8// 根据byteIndex确定从combined中选取比特位所在的字节byteValue := combined[byteIndex]// 从combined特定字节bytevalue的特定比特位里取出 放入resultbittarget = bitcount % 8result[bitcount/8] |= (byteValue & (1 << (7 - (bitIndex % 8)))) >> (7 - (bitIndex % 8)) << bittargetbitcount++// 记录所有子密钥的步骤在上面subkey}}fmt.Println("本轮PC-2完成。")return result
}// 3. 异或
func xorBytes(a, b []byte) []byte {if len(a) != len(b) {panic("输入的两个字节切片长度不相等")}result := make([]byte, len(a))// fmt.Println(len(a), len(b))for i := range a {result[i] = a[i] ^ b[i]}return result
}// 4. S盒 6位变4位
func Sbox48To32(input []byte) []byte {if len(input) != 6 {panic("Invalid input length for SBox48To32. Expected 6 bytes (48 bits).")}output := make([]byte, 4)var out uint32 = 0// 定义一个掩码，用于提取6位数据块中的每一位const bitMask uint8 = 0x20// 遍历8个6位数据块for i := 0; i < 8; i++ {// 提取当前6位数据块var b uint8for j := 0; j < 6; j++ {// 根据当前循环的索引和位掩码，从输入字节切片中提取相应的位bitIndex := (i*6 + j) % 6// 按位或// 可以提取出 input[bitIndex] 字节中与 bitMask 对应的那一位。b |= (input[bitIndex] & bitMask) >> (7 - (j % 6))}// 计算行索引：第1位和第6位r := (b&1)<<1 + (b >> 5)// 计算列索引：第2到第5位c := ((b>>1)&1)<<3 + ((b>>2)&1)<<2 + ((b>>3)&1)<<1 + ((b >> 4) & 1)// 从对应的S盒中获取值o := src.SBoxes[i][r][c]// 将获取的值设置到输出结果中，按位或out |= uint32(o) << (i * 4)}// 将处理后的结果填充到输出切片for i := 0; i < 4; i++ {output[i] = byte((out >> (i * 8)) & 0xff)}fmt.Printf("S盒结果：%v\n", output)return output
}// 5. P盒
func PboxExchange(input []byte) []byte {Pbox := [][]int{{16, 7, 20, 21},{29, 12, 28, 17},{1, 15, 23, 26},{5, 18, 31, 10},{2, 8, 24, 14},{32, 27, 3, 9},{19, 13, 30, 6},{22, 11, 4, 25},}if len(input) != 4 {panic("Invalid input length for PboxExchange. Expected 4 bytes(32bits).")}// 将输入的字节切片转换为uint32类型var inputUint32 uint32for i, b := range input {inputUint32 |= uint32(b) << (uint32(i) * 8)}fmt.Println("转换为uint32后的输入值: ", inputUint32)var out uint32 = 0for i := 0; i < 8; i++ {for j := 0; j < 4; j++ {index := Pbox[i][j] - 1bit := (inputUint32 >> uint32(31-index)) & 1out |= bit << uint32(i*4+j)}//fmt.Printf("经过第%d行Pbox置换操作后out的值（十六进制）: %x\n", i, out)}// 将置换后的结果转换为字节切片返回output := make([]byte, 4)for i := 0; i < 4; i++ {output[i] = byte((out >> (i * 8)) & 0xff)}fmt.Println("P盒output: ", output)return output
}// 解密函数，执行与加密相反的操作流程
func Decrypt(ciphertext []byte, subkeys [][]byte) []byte {fmt.Println("开始解密……")// 用于存储每组解密后的结果// 转换成字节切片组，8个字节一组var cipherGroups [][]bytefor i := 0; i < len(ciphertext); i += 8 {endIndex := i + 8if endIndex > len(ciphertext) {endIndex = len(ciphertext)}cipherGroups = append(cipherGroups, []byte(ciphertext[i:endIndex]))}// 用于存储每组解密后的结果var decryptedGroups [][]bytefor _, group := range cipherGroups {println("开始初始置换")// 3. 填充明文 初始置换//paddedGroup := PadPlaintext(group)permutedText := InitialPermutation(group)println("初始置换完毕")// 4. 拆分L0和R0//println("开始拆分L0和R0")L, R := SplitLR(permutedText)println("拆分L0和R0完毕")// 5. 进行16轮加密for i := 0; i < 16; i++ {// 扩展RexpandedR := Expand32To48(R)//println("扩展完毕")// 生成子密钥subkey := subkeys[15-i]// 异或xored := xorBytes(expandedR, subkey)//println("异或完毕")fmt.Printf("异或结果：%v\n", xored)// S盒变换sboxed := Sbox48To32(xored)//println("S盒完毕")// P盒变换pboxed := PboxExchange(sboxed)//println("P盒完毕")// 与L异或newL := xorBytes(L, pboxed)//println("二次异或完毕")L = RR = newL}// 6. 合并L16和R16plaintext := MergeLR(L, R)// 7. 逆置换finalCiphertext := ReversePermutation(plaintext)decryptedGroups = append(decryptedGroups, finalCiphertext)}// 将所有组的解密结果组合起来finalDecryptedText := []byte{}for _, decryptedGroup := range decryptedGroups {finalDecryptedText = append(finalDecryptedText, decryptedGroup...)}return finalDecryptedText
}func main() {println("请输入明文：")reader := bufio.NewReader(os.Stdin)plaintextStr, err := reader.ReadString('\n')if err != nil {fmt.Println("读取输入时出错：", err)return}// 去除字符串末尾的换行符plaintextStr = strings.TrimSpace(plaintextStr)// 转换成字节切片组，8个字节一组var plainGroups [][]bytefor i := 0; i < len(plaintextStr); i += 8 {endIndex := i + 8if endIndex > len(plaintextStr) {endIndex = len(plaintextStr)}plainGroups = append(plainGroups, []byte(plaintextStr[i:endIndex]))}// 假设主密钥为8字节（64位）println("请输入密钥：")reader = bufio.NewReader(os.Stdin)keyyy, err := reader.ReadString('\n')if err != nil {fmt.Println("读取输入时出错：", err)return}// 去除字符串末尾的换行符keyStr := strings.TrimSpace(keyyy)key := []byte(keyStr)//key := []byte{0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, 0xde, 0xf0}println("开始填充密钥")// 1. 填充密钥（如果需要）newKey := PadKeyWithRandom(key)//println("填充结果：", newKey)println("密钥填充结果：")for _, b := range newKey {fmt.Printf("%02x ", b)}println("\n开始生成子密钥……")// 2. 生成子密钥subkeys := GenerateSubkey(newKey)// 用于存储每组加密后的结果var encryptedGroups [][]bytefmt.Printf("明文字节组数：%d\n", len(plainGroups))for _, group := range plainGroups {//println(len(group)) 不出意外是一个8一个3 因为This is DESprintln("开始初始置换")// 3. 明文填充 + 初始置换paddedGroup := PadPlaintext(group)permutedText := InitialPermutation(paddedGroup)println("初始置换完毕")// 4. 拆分L0和R0//println("开始拆分L0和R0")L, R := SplitLR(permutedText)println("拆分L0和R0完毕")// 5. 进行16轮加密for i := 0; i < 16; i++ {// 扩展RexpandedR := Expand32To48(R)//println("扩展完毕")// 生成子密钥subkey := subkeys[i]// 异或xored := xorBytes(expandedR, subkey)//println("异或完毕")fmt.Printf("异或结果：%v\n", xored)// S盒变换sboxed := Sbox48To32(xored)//println("S盒完毕")// P盒变换pboxed := PboxExchange(sboxed)//println("P盒完毕")// 与L异或newL := xorBytes(L, pboxed)//println("二次异或完毕")L = RR = newL}// 6. 合并L16和R16ciphertext := MergeLR(L, R)// 7. 逆置换finalCiphertext := ReversePermutation(ciphertext)encryptedGroups = append(encryptedGroups, finalCiphertext)}// 将所有组的加密结果组合起来finalEncryptedText := []byte{}for _, encryptedGroup := range encryptedGroups {finalEncryptedText = append(finalEncryptedText, encryptedGroup...)}// 调用解密函数进行解密验证decryptedText := Decrypt(finalEncryptedText, subkeys)fmt.Printf("明文解析字节内容：%d\n", plainGroups)fmt.Printf("加密后的密文: %d\n", finalEncryptedText)fmt.Printf("解密后的明文: %d\n", decryptedText)/*// 示例用法data := []byte{0x12, 0x34, 0x56, 0x78}index := 3result := CircularLeftShift(data, index)fmt.Printf("原始数据: %x\n", data)fmt.Printf("循环左移后的结果: %x\n", result)*/
}
