C++ Base64 编码解码库源码下载及示例代码

您可以从以下链接下载C++的Base64编码和解码的源码：\n\n1. https://github.com/ReneNyffenegger/cpp-base64\n在该链接中，您可以找到基于C++的Base64编码和解码的实现代码。该库提供了一个简单的API来进行Base64编码和解码。\n\n2. https://github.com/tomykaira/base64\n这是另一个C++的Base64编码和解码库，提供了一个简单的API接口来进行Base64的转换。\n\n以下是一个简单的C++代码实现Base64编码和解码的示例：\n\ncpp\n#include <iostream>\n#include <string>\n#include <vector>\n\nstatic const std::string base64_chars =\n "ABCDEFGHIJKLMNOPQRSTUVWXYZ"\n "abcdefghijklmnopqrstuvwxyz"\n "0123456789+/";\n\nstd::string base64_encode(const std::string& input) {\n std::string encoded;\n int i = 0;\n int j = 0;\n uint32_t char_array_3[3];\n uint32_t char_array_4[4];\n\n for (const auto& c : input) {\n char_array_3[i++] = c;\n if (i == 3) {\n char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;\n char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);\n char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);\n char_array_4[3] = char_array_3[2] & 0x3f;\n\n for (i = 0; i < 4; i++) {\n encoded += base64_chars[char_array_4[i]];\n }\n i = 0;\n }\n }\n\n if (i > 0) {\n for (j = i; j < 3; j++) {\n char_array_3[j] = '\0';\n }\n\n char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;\n char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);\n char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);\n\n for (j = 0; j < i + 1; j++) {\n encoded += base64_chars[char_array_4[j]];\n }\n\n while (i++ < 3) {\n encoded += '=';\n }\n }\n\n return encoded;\n}\n\nstd::string base64_decode(const std::string& input) {\n std::string decoded;\n int i = 0;\n int j = 0;\n uint32_t char_array_4[4];\n uint32_t char_array_3[3];\n\n for (const auto& c : input) {\n if (c == '=') {\n break;\n }\n\n char_array_4[i++] = c;\n if (i == 4) {\n for (i = 0; i < 4; i++) {\n char_array_4[i] = base64_chars.find(char_array_4[i]);\n }\n\n char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);\n char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);\n char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];\n\n for (i = 0; i < 3; i++) {\n decoded += char_array_3[i];\n }\n i = 0;\n }\n }\n\n if (i > 0) {\n for (j = i; j < 4; j++) {\n char_array_4[j] = 0;\n }\n\n for (j = 0; j < 4; j++) {\n char_array_4[j] = base64_chars.find(char_array_4[j]);\n }\n\n char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);\n char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);\n\n for (j = 0; j < i - 1; j++) {\n decoded += char_array_3[j];\n }\n }\n\n return decoded;\n}\n\nint main() {\n std::string input = "Hello, World!";\n std::string encoded = base64_encode(input);\n std::string decoded = base64_decode(encoded);\n\n std::cout << "Original: " << input << std::endl;\n std::cout << "Encoded: " << encoded << std::endl;\n std::cout << "Decoded: " << decoded << std::endl;\n\n return 0;\n}\n\n\n这个示例代码演示了如何使用base64_encode函数将输入字符串进行Base64编码，然后使用base64_decode函数将编码的字符串解码回原始字符串。