Base64 编码解码C++实现

来源：互联网发布：dreamweaver破解版mac 编辑：程序博客网时间：2024/06/05 07:07
#ifndef __BASE64_H__#define __BASE64_H__#include <string>using namespace std;/*    The character array*/const string kBase64Array = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";/*    Is the character in base64?*/bool __IsBase64( BYTE b ){    return (         (b >= '0' && b <= '9') ||         (b >= 'a' && b <= 'z') ||         (b >= 'A' && b <= 'Z') ||        b == '+' ||         b == '/' );}/*    Encode*/string Base64Encode(    LPCVOID vpData,     SIZE_T Size ){    string ret;    const BYTE* pData = (const BYTE *) vpData;    int i = 0;    int j = 0;    BYTE char_array_3[3];    BYTE char_array_4[4];    while (Size--)    {        char_array_3[i++] = *(pData++);        if (i == 3)        {            char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;            char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);            char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);            char_array_4[3] = char_array_3[2] & 0x3f;            for(i = 0; i < 4; i++)                ret += kBase64Array[char_array_4[i]];            i = 0;        }    }    if (i)    {        for(j = i; j < 3; j++)            char_array_3[j] = '\0';        char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;        char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);        char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);        char_array_4[3] = char_array_3[2] & 0x3f;        for (j = 0; j < i + 1; j++)            ret += kBase64Array[char_array_4[j]];        while(i++ < 3)            ret += '=';    }    return ret;}/*    Decode*/string Base64Decode(     LPCVOID pData,     SIZE_T Size ){    string ret;    string encoded_string( (const char *)pData );    int in_len = (int)encoded_string.size();    int i = 0;    int j = 0;    int in_ = 0;    BYTE char_array_4[4], char_array_3[3];    while (in_len-- && ( encoded_string[in_] != '=') && __IsBase64(encoded_string[in_]))    {        char_array_4[i++] = encoded_string[in_]; in_++;        if (i ==4)        {            for (i = 0; i <4; i++)                char_array_4[i] = (BYTE)kBase64Array.find(char_array_4[i]);            char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);            char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);            char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];            for (i = 0; (i < 3); i++)                ret += char_array_3[i];            i = 0;        }    }    if (i)    {        for (j = i; j <4; j++)            char_array_4[j] = 0;        for (j = 0; j <4; j++)            char_array_4[j] = (BYTE)kBase64Array.find(char_array_4[j]);        char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);        char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);        char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];        for (j = 0; (j < i - 1); j++)            ret += char_array_3[j];    }    return ret;}#endif
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