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@caromdreamer
Created March 29, 2021 02:25
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  1. DIRE created this gist Mar 29, 2021.
    94 changes: 94 additions & 0 deletions base64.cpp
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,94 @@
    #include "base64.h"
    #include <iostream>

    static const std::string base64_chars =
    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    "abcdefghijklmnopqrstuvwxyz"
    "0123456789+/";


    static inline bool is_base64(BYTE c) {
    return (isalnum(c) || (c == '+') || (c == '/'));
    }

    std::string base64_encode(BYTE const* buf, unsigned int bufLen) {
    std::string ret;
    int i = 0;
    int j = 0;
    BYTE char_array_3[3];
    BYTE char_array_4[4];

    while (bufLen--) {
    char_array_3[i++] = *(buf++);
    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 += base64_chars[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 += base64_chars[char_array_4[j]];

    while((i++ < 3))
    ret += '=';
    }

    return ret;
    }

    std::vector<BYTE> base64_decode(std::string const& encoded_string) {
    int in_len = encoded_string.size();
    int i = 0;
    int j = 0;
    int in_ = 0;
    BYTE char_array_4[4], char_array_3[3];
    std::vector<BYTE> ret;

    while (in_len-- && ( encoded_string[in_] != '=') && is_base64(encoded_string[in_])) {
    char_array_4[i++] = encoded_string[in_]; in_++;
    if (i ==4) {
    for (i = 0; i <4; i++)
    char_array_4[i] = base64_chars.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.push_back(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] = base64_chars.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.push_back(char_array_3[j]);
    }

    return ret;
    }
    11 changes: 11 additions & 0 deletions base64.h
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,11 @@
    #ifndef _BASE64_H_
    #define _BASE64_H_

    #include <vector>
    #include <string>
    typedef unsigned char BYTE;

    std::string base64_encode(BYTE const* buf, unsigned int bufLen);
    std::vector<BYTE> base64_decode(std::string const&);

    #endif
    4 changes: 4 additions & 0 deletions example.cpp
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,4 @@
    std::vector<BYTE> myData;
    ...
    std::string encodedData = base64_encode(&myData[0], myData.size());
    std::vector<BYTE> decodedData = base64_decode(encodedData);