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#include <Base64.h>
static char cb64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
String Base64::encode_block(unsigned char in_tab[3], int len) {
char r[5];
r[0] = cb64[in_tab[0] >> 2];
r[1] = cb64[((in_tab[0] & 3) << 4) | ((in_tab[1] & 240) >> 4)];
r[2] = len > 1 ? cb64[((in_tab[1] & 15) << 2) | ((in_tab[2] & 192) >> 6)] : '=';
r[3] = len > 2 ? cb64[in_tab[2] & 63] : '=';
r[4] = 0;
return r;
}
String Base64::encode(char * data, int stream_size) {
String encoded = "";
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];
}
encoded += encode_block(in_tab, len);
s_pos += 3;
stream_size -= 3;
}
return encoded;
}
int Base64::stri(char x) {
char * p = strchr(cb64, x);
return ((x == '=') || (p == 0)) ? -1 : (p - cb64);
}
int 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;
}
unsigned char * Base64::decode(const String & str_in, int * len_out) {
int s_len = str_in.strlen() / 4, len = 0, i, j, t_len;
char s1, s2, s3, s4;
unsigned char t_out[2];
unsigned char * out = (unsigned char *) malloc(s_len * 3);
for (i = 0; i < s_len; i++) {
s1 = str_in[i * 4 + 0];
s2 = str_in[i * 4 + 1];
s3 = str_in[i * 4 + 2];
s4 = str_in[i * 4 + 3];
t_len = decode_block(s1, s2, s3, s4, t_out);
for (j = 0; j < t_len; j++) {
out[i * 3 + j] = t_out[j];
}
len += t_len;
}
if (len_out) {
*len_out = len;
}
return out;
}
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