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#include <functional>
#include "Base64.h"
static char cb64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
static char lookup[] = {
// x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 xA xB xC xD xE xF
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 0x
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 1x
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63, // 2x
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1, // 3x
-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, // 4x
15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, // 5x
-1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, // 6x
41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1, // 7x
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 8x
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 9x
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // Ax
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // Bx
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // Cx
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // Dx
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // Ex
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // Fx
};
const double Balau::Base64::ratio = 4 / 3;
void Balau::Base64::encode_block(unsigned char in_tab[3], int len, char out[5]) {
out[0] = cb64[in_tab[0] >> 2];
out[1] = cb64[((in_tab[0] & 3) << 4) | ((in_tab[1] & 240) >> 4)];
out[2] = len > 1 ? cb64[((in_tab[1] & 15) << 2) | ((in_tab[2] & 192) >> 6)] : '=';
out[3] = len > 2 ? cb64[in_tab[2] & 63] : '=';
out[4] = 0;
}
Balau::String Balau::Base64::encode(const uint8_t * data, int stream_size) {
String encoded;
encoded.reserve(stream_size * ratio + 1);
unsigned char in_tab[3];
int len, i, s_pos;
s_pos = 0;
while (stream_size > 0) {
in_tab[0] = 0;
in_tab[1] = 0;
in_tab[2] = 0;
len = stream_size >= 3 ? 3 : stream_size;
for (i = 0; i < len; i++) {
in_tab[i] = data[s_pos + i];
}
char block[5];
encode_block(in_tab, len, block);
encoded += block;
s_pos += 3;
stream_size -= 3;
}
return encoded;
}
int Balau::Base64::stri(char x) {
return lookup[(unsigned char) x];
}
int Balau::Base64::decode_block(char s1, char s2, char s3, char s4, unsigned char * out_tab) {
int len, sb1, sb2, sb3, sb4;
len = s3 == '=' ? 1 : s4 == '=' ? 2 : 3;
s3 = (s3 == '=') || (s3 == 0) ? 'A' : s3;
s4 = (s4 == '=') || (s4 == 0) ? 'A' : s4;
sb1 = stri(s1);
sb2 = stri(s2);
sb3 = stri(s3);
sb4 = stri(s4);
out_tab[0] = (sb1 << 2) | (sb2 >> 4);
out_tab[1] = ((sb2 << 4) & 255) | (sb3 >> 2);
out_tab[2] = ((sb3 << 6) & 240) | sb4;
return len;
}
int Balau::Base64::decode(const String & str_in, uint8_t * data_out, size_t outLen) {
int s_len = str_in.strlen(), len = 0, i, t_len, idx;
char s1, s2, s3, s4;
unsigned char t_out[3];
unsigned char * p = data_out;
bool failure = false;
std::function<char()> readNext = [&]() {
char r = '=';
if (idx >= s_len)
return r;
do {
r = str_in[idx++];
} while (r == '\r' || r == '\n' || r == ' ' || r == '\t');
if (isdigit(r) || isalpha(r) || r == '+' || r == '/')
return r;
failure = true;
return '=';
};
for (idx = 0; idx < s_len || failure; len += t_len) {
s1 = readNext();
s2 = readNext();
s3 = readNext();
s4 = readNext();
t_len = decode_block(s1, s2, s3, s4, t_out);
for (i = 0; i < t_len; i++) {
if (outLen == 0)
return -1;
*(p++) = t_out[i];
outLen--;
}
}
return failure ? -1 : len;
}
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