/*
* This code originally came from here
*
* http://base64.sourceforge.net/b64.c
*
* already with MIT license, which is retained.
*
* LICENCE: Copyright (c) 2001 Bob Trower, Trantor Standard Systems Inc.
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated
* documentation files (the "Software"), to deal in the
* Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute,
* sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall
* be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
* KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
* WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
* PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS
* OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* VERSION HISTORY:
* Bob Trower 08/04/01 -- Create Version 0.00.00B
*
* I cleaned it up quite a bit to match the (linux kernel) style of the rest
* of libwebsockets
*/
#include <libwebsockets.h>
#include <stdio.h>
#include <string.h>
#include "private-lib-core.h"
static const char encode_orig[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"abcdefghijklmnopqrstuvwxyz0123456789+/";
static const char encode_url[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"abcdefghijklmnopqrstuvwxyz0123456789-_";
static const char decode[] = "|$$$}rstuvwxyz{$$$$$$$>?@ABCDEFGHIJKLMNOPQRSTUVW"
"$$$$$$XYZ[\\]^_`abcdefghijklmnopq";
static int
_lws_b64_encode_string(const char *encode, const char *in, int in_len,
char *out, int out_size)
{
unsigned char triple[3];
int i, done = 0;
while (in_len) {
int len = 0;
for (i = 0; i < 3; i++) {
if (in_len) {
triple[i] = *in++;
len++;
in_len--;
} else
triple[i] = 0;
}
if (done + 4 >= out_size)
return -1;
*out++ = encode[triple[0] >> 2];
*out++ = encode[(((triple[0] & 0x03) << 4) & 0x30) |
(((triple[1] & 0xf0) >> 4) & 0x0f)];
*out++ = (len > 1 ? encode[(((triple[1] & 0x0f) << 2) & 0x3c) |
(((triple[2] & 0xc0) >> 6) & 3)] : '=');
*out++ = (len > 2 ? encode[triple[2] & 0x3f] : '=');
done += 4;
}
if (done + 1 >= out_size)
return -1;
*out++ = '\0';
return done;
}
int
lws_b64_encode_string(const char *in, int in_len, char *out, int out_size)
{
return _lws_b64_encode_string(encode_orig, in, in_len, out, out_size);
}
int
lws_b64_encode_string_url(const char *in, int in_len, char *out, int out_size)
{
return _lws_b64_encode_string(encode_url, in, in_len, out, out_size);
}
void
lws_b64_decode_state_init(struct lws_b64state *state)
{
memset(state, 0, sizeof(*state));
}
int
lws_b64_decode_stateful(struct lws_b64state *s, const char *in, size_t *in_len,
uint8_t *out, size_t *out_size, int final)
{
const char *orig_in = in, *end_in = in + *in_len;
uint8_t *orig_out = out, *end_out = out + *out_size;
while (in < end_in && *in && out + 4 < end_out) {
for (; s->i < 4 && in < end_in && *in; s->i++) {
uint8_t v;
v = 0;
s->c = 0;
while (in < end_in && *in && !v) {
s->c = v = *in++;
/* support the url base64 variant too */
if (v == '-')
s->c = v = '+';
if (v == '_')
s->c = v = '/';
v = (v < 43 || v > 122) ? 0 : decode[v - 43];
if (v)
v = (v == '$') ? 0 : v - 61;
}
if (s->c) {
s->len++;
if (v)
s->quad[s->i] = v - 1;
} else
s->quad[s->i] = 0;
}
if (s->i != 4 && !final)
continue;
s->i = 0;
/*
* "The '==' sequence indicates that the last group contained
* only one byte, and '=' indicates that it contained two
* bytes." (wikipedia)
*/
if ((in >= end_in || !*in) && s->c == '=')
s->len--;
if (s->len >= 2)
*out++ = s->quad[0] << 2 | s->quad[1] >> 4;
if (s->len >= 3)
*out++ = s->quad[1] << 4 | s->quad[2] >> 2;
if (s->len >= 4)
*out++ = ((s->quad[2] << 6) & 0xc0) | s->quad[3];
s->done += s->len - 1;
s->len = 0;
}
*out = '\0';
*in_len = in - orig_in;
*out_size = out - orig_out;
return 0;
}
/*
* returns length of decoded string in out, or -1 if out was too small
* according to out_size
*
* Only reads up to in_len chars, otherwise if in_len is -1 on entry reads until
* the first NUL in the input.
*/
static size_t
_lws_b64_decode_string(const char *in, int in_len, char *out, int out_size)
{
struct lws_b64state state;
size_t il = (size_t)in_len, ol = out_size;
if (in_len == -1)
il = strlen(in);
lws_b64_decode_state_init(&state);
lws_b64_decode_stateful(&state, in, &il, (uint8_t *)out, &ol, 1);
if (!il)
return 0;
return ol;
}
int
lws_b64_decode_string(const char *in, char *out, int out_size)
{
return (int)_lws_b64_decode_string(in, -1, out, out_size);
}
int
lws_b64_decode_string_len(const char *in, int in_len, char *out, int out_size)
{
return (int)_lws_b64_decode_string(in, in_len, out, out_size);
}
#if 0
static const char * const plaintext[] = {
"any carnal pleasure.",
"any carnal pleasure",
"any carnal pleasur",
"any carnal pleasu",
"any carnal pleas",
"Admin:kloikloi"
};
static const char * const coded[] = {
"YW55IGNhcm5hbCBwbGVhc3VyZS4=",
"YW55IGNhcm5hbCBwbGVhc3VyZQ==",
"YW55IGNhcm5hbCBwbGVhc3Vy",
"YW55IGNhcm5hbCBwbGVhc3U=",
"YW55IGNhcm5hbCBwbGVhcw==",
"QWRtaW46a2xvaWtsb2k="
};
int
lws_b64_selftest(void)
{
char buf[64];
unsigned int n, r = 0;
unsigned int test;
lwsl_notice("%s\n", __func__);
/* examples from https://en.wikipedia.org/wiki/Base64 */
for (test = 0; test < (int)LWS_ARRAY_SIZE(plaintext); test++) {
buf[sizeof(buf) - 1] = '\0';
n = lws_b64_encode_string(plaintext[test],
strlen(plaintext[test]), buf, sizeof buf);
if (n != strlen(coded[test]) || strcmp(buf, coded[test])) {
lwsl_err("Failed lws_b64 encode selftest "
"%d result '%s' %d\n", test, buf, n);
r = -1;
}
buf[sizeof(buf) - 1] = '\0';
n = lws_b64_decode_string(coded[test], buf, sizeof buf);
if (n != strlen(plaintext[test]) ||
strcmp(buf, plaintext[test])) {
lwsl_err("Failed lws_b64 decode selftest "
"%d result '%s' / '%s', %d / %zu\n",
test, buf, plaintext[test], n,
strlen(plaintext[test]));
lwsl_hexdump_err(buf, n);
r = -1;
}
}
if (!r)
lwsl_notice("Base 64 selftests passed\n");
else
lwsl_notice("Base64 selftests failed\n");
return r;
}
#endif