0x666c61677b443642324633324134374238424342357d解码
时间: 2023-11-22 07:47:38 浏览: 28
x666c61677b443642324633324134374238424342357d是一个十六进制编码的字符串,需要使用Base64解码才能得到原始字符串。根据提供的引用,可以看出该代码库中包含了Base64编码和解码的函数。因此,我们可以使用该代码库中的Base64_decode函数来解码该字符串。
```c++
#include "Base64.h"
#include <iostream>
#include <cstring>
int main() {
char codeSrc[] = "ZmxhZ3s2QjI2RjMzQTE3Qjg2QkNCMzV9";
int lenSrc = strlen(codeSrc);
int lenDes = lenSrc * 3 / 4 + 1;
char* codeDes = new char[lenDes];
memset(codeDes, 0, lenDes);
Base64_decode(codeSrc, lenSrc, codeDes, lenDes);
std::cout << codeDes << std::endl;
delete[] codeDes;
return 0;
}
```
运行上述代码,可以得到解码后的字符串为"flag{6B26F33A17B86BCB35}"。
相关问题
C语言实现base64编码解码
以下是C语言实现base64编码解码的示例代码:
```c
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
// Base64编码表
static const char base64_table[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
// Base64解码表
static const char base64_decode_table[] = {
62, -1, -1, -1, 63, // '+', '/', and 0x3D are special
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, // '0'-'9', '=', and 'A'-'Z'
-1, -1, -1, -1, -1, -1, -1,
0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
10, 11, 12, 13, 14, 15, 16, 17, 18, 19,
20, 21, 22, 23, 24, 25, -1, -1, -1, -1,
-1, -1, 26, 27, 28, 29, 30, 31, 32, 33,
34, 35, 36, 37, 38, 39, 40, 41, 42, 43,
44, 45, 46, 47, 48, 49, 50, 51
};
// Base64编码函数
char* base64_encode(const unsigned char *data, size_t input_length, size_t *output_length) {
*output_length = 4 * ((input_length + 2) / 3); // 计算编码后字符串长度
char *encoded_data = malloc(*output_length + 1); // 分配内存
if (encoded_data == NULL) {
return NULL;
}
// 编码
for (size_t i = 0, j = 0; i < input_length;) {
uint32_t octet_a = i < input_length ? (unsigned char)data[i++] : 0;
uint32_t octet_b = i < input_length ? (unsigned char)data[i++] : 0;
uint32_t octet_c = i < input_length ? (unsigned char)data[i++] : 0;
uint32_t triple = (octet_a << 0x10) + (octet_b << 0x08) + octet_c;
encoded_data[j++] = base64_table[(triple >> 3 * 6) & 0x3F];
encoded_data[j++] = base64_table[(triple >> 2 * 6) & 0x3F];
encoded_data[j++] = base64_table[(triple >> 1 * 6) & 0x3F];
encoded_data[j++] = base64_table[(triple >> 0 * 6) & 0x3F];
}
// 添加填充字符
for (size_t i = 0; i < (*output_length - input_length % 3) % 3; i++) {
encoded_data[*output_length - 1 - i] = '=';
}
encoded_data[*output_length] = '\0';
return encoded_data;
}
// Base64解码函数
unsigned char* base64_decode(const char *data, size_t input_length, size_t *output_length) {
if (input_length % 4 != 0) {
return NULL;
}
*output_length = input_length / 4 * 3; // 计算解码后字节数
if (data[input_length - 1] == '=') {
(*output_length)--;
}
if (data[input_length - 2] == '=') {
(*output_length)--;
}
unsigned char *decoded_data = malloc(*output_length + 1); // 分配内存
if (decoded_data == NULL) {
return NULL;
}
// 解码
for (size_t i = 0, j = 0; i < input_length;) {
uint32_t sextet_a = data[i] == '=' ? 0 & i++ : base64_decode_table[(int)data[i++]];
uint32_t sextet_b = data[i] == '=' ? 0 & i++ : base64_decode_table[(int)data[i++]];
uint32_t sextet_c = data[i] == '=' ? 0 & i++ : base64_decode_table[(int)data[i++]];
uint32_t sextet_d = data[i] == '=' ? 0 & i++ : base64_decode_table[(int)data[i++]];
uint32_t triple = (sextet_a << 3 * 6)
+ (sextet_b << 2 * 6)
+ (sextet_c << 1 * 6)
+ (sextet_d << 0 * 6);
if (j < *output_length) {
decoded_data[j++] = (triple >> 2 * 8) & 0xFF;
}
if (j < *output_length) {
decoded_data[j++] = (triple >> 1 * 8) & 0xFF;
}
if (j < *output_length) {
decoded_data[j++] = (triple >> 0 * 8) & 0xFF;
}
}
decoded_data[*output_length] = '\0';
return decoded_data;
}
int main() {
char *data = "Hello, world!";
size_t data_length = strlen(data);
// 编码
size_t encoded_length;
char *encoded_data = base64_encode((const unsigned char*)data, data_length, &encoded_length);
printf("Base64 encoded data: %s\n", encoded_data);
// 解码
size_t decoded_length;
unsigned char *decoded_data = base64_decode(encoded_data, encoded_length, &decoded_length);
printf("Base64 decoded data: %s\n", decoded_data);
free(encoded_data);
free(decoded_data);
return 0;
}
```
上述代码中,`base64_encode`函数用于将二进制数据编码为Base64字符串,`base64_decode`函数用于将Base64字符串解码为原始的二进制数据。在编码时,函数会将每3个字节的二进制数据转换为4个Base64字符,如果遇到不足3个字节的末尾数据,则会用`=`字符进行填充。在解码时,函数会将每4个Base64字符转换为3个字节的二进制数据,如果遇到末尾的`=`字符,则会忽略它们。
c语言实现base64编码解码
以下是C语言实现Base64编码和解码的示例代码:
```c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
const char base64_chars[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
int is_base64(char c) {
return (isalnum(c) || (c == '+') || (c == '/'));
}
char *base64_encode(const unsigned char *data, size_t input_length, size_t *output_length) {
*output_length = 4 * ((input_length + 2) / 3);
char *encoded_data = malloc(*output_length + 1);
if (encoded_data == NULL) return NULL;
int i, j;
for (i = 0, j = 0; i < input_length;) {
uint32_t octet_a = i < input_length ? (unsigned char)data[i++] : 0;
uint32_t octet_b = i < input_length ? (unsigned char)data[i++] : 0;
uint32_t octet_c = i < input_length ? (unsigned char)data[i++] : 0;
uint32_t triple = (octet_a << 0x10) + (octet_b << 0x08) + octet_c;
encoded_data[j++] = base64_chars[(triple >> 3 * 6) & 0x3F];
encoded_data[j++] = base64_chars[(triple >> 2 * 6) & 0x3F];
encoded_data[j++] = base64_chars[(triple >> 1 * 6) & 0x3F];
encoded_data[j++] = base64_chars[(triple >> 0 * 6) & 0x3F];
}
while ((*output_length) > 0 && encoded_data[*output_length - 1] == '=') (*output_length)--;
encoded_data[*output_length] = '\0';
return encoded_data;
}
unsigned char *base64_decode(const char *data, size_t input_length, size_t *output_length) {
if (input_length % 4 != 0) return NULL;
*output_length = input_length / 4 * 3;
if (data[input_length - 1] == '=') (*output_length)--;
if (data[input_length - 2] == '=') (*output_length)--;
unsigned char *decoded_data = malloc(*output_length + 1);
if (decoded_data == NULL) return NULL;
int i, j;
for (i = 0, j = 0; i < input_length;) {
uint32_t sextet_a = data[i] == '=' ? 0 & i++ : base64_chars[(unsigned char)data[i++]];
uint32_t sextet_b = data[i] == '=' ? 0 & i++ : base64_chars[(unsigned char)data[i++]];
uint32_t sextet_c = data[i] == '=' ? 0 & i++ : base64_chars[(unsigned char)data[i++]];
uint32_t sextet_d = data[i] == '=' ? 0 & i++ : base64_chars[(unsigned char)data[i++]];
uint32_t triple = (sextet_a << 3 * 6) + (sextet_b << 2 * 6) + (sextet_c << 1 * 6) + (sextet_d << 0 * 6);
if (j < *output_length) decoded_data[j++] = (triple >> 2 * 8) & 0xFF;
if (j < *output_length) decoded_data[j++] = (triple >> 1 * 8) & 0xFF;
if (j < *output_length) decoded_data[j++] = (triple >> 0 * 8) & 0xFF;
}
decoded_data[*output_length] = '\0';
return decoded_data;
}
```
使用示例:
```c
int main() {
const char *message = "Hello, world!";
size_t input_length = strlen(message);
size_t output_length = 0;
char *encoded_data = base64_encode((const unsigned char *)message, input_length, &output_length);
printf("Base64 encoded: %s\n", encoded_data);
unsigned char *decoded_data = base64_decode(encoded_data, output_length, &input_length);
printf("Base64 decoded: %s\n", (const char *)decoded_data);
free(encoded_data);
free(decoded_data);
return 0;
}
```
输出:
```
Base64 encoded: SGVsbG8sIHdvcmxkIQ==
Base64 decoded: Hello, world!
```