blob: 79e86c20002b7fef7acfb4e910b864206c60737d [file] [log] [blame]
/*
* Ascii to Base64 conversion as described in RFC1421.
* Copyright 2006 Willy Tarreau <willy@w.ods.org>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
*/
#include <include/base64.h>
/* Encodes <ilen> bytes from <in> to <out> for at most <olen> chars (including
* the trailing zero). Returns the number of bytes written. No check is made
* for <in> or <out> to be NULL. Returns negative value if <olen> is too short
* to accept <ilen>. 4 output bytes are produced for 1 to 3 input bytes.
*/
int a2base64(char *in, int ilen, char *out, int olen)
{
char base64[64]="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
int convlen;
convlen = ((ilen + 2) / 3) * 4;
if (convlen >= olen)
return -1;
/* we don't need to check olen anymore */
while (ilen >= 3) {
out[0] = base64[(((unsigned char)in[0]) >> 2)];
out[1] = base64[(((unsigned char)in[0] & 0x03) << 4) | (((unsigned char)in[1]) >> 4)];
out[2] = base64[(((unsigned char)in[1] & 0x0F) << 2) | (((unsigned char)in[2]) >> 6)];
out[3] = base64[(((unsigned char)in[2] & 0x3F))];
out += 4;
in += 3; ilen -= 3;
}
if (!ilen) {
out[0] = '\0';
} else {
out[0] = base64[((unsigned char)in[0]) >> 2];
if (ilen == 1) {
out[1] = base64[((unsigned char)in[0] & 0x03) << 4];
out[2] = '=';
} else {
out[1] = base64[(((unsigned char)in[0] & 0x03) << 4) |
(((unsigned char)in[1]) >> 4)];
out[2] = base64[((unsigned char)in[1] & 0x0F) << 2];
}
out[3] = '=';
out[4] = '\0';
}
return convlen;
}