/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.haxx.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
***************************************************************************/
/* Base64 encoding/decoding */
#include "curl_setup.h"
#include "urldata.h" /* for the Curl_easy definition */
#include "warnless.h"
#include "curl_base64.h"
#include "non-ascii.h"
/* The last 3 #include files should be in this order */
#include "curl_printf.h"
#include "curl_memory.h"
#include "memdebug.h"
/* ---- Base64 Encoding/Decoding Table --- */
static const char base64[]=
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
/* The Base 64 encoding with an URL and filename safe alphabet, RFC 4648
section 5 */
static const char base64url[]=
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_";
static size_t decodeQuantum(unsigned char *dest, const char *src)
{
size_t padding = 0;
const char *s, *p;
unsigned long i, x = 0;
for(i = 0, s = src; i < 4; i++, s++) {
unsigned long v = 0;
if(*s == '=') {
x = (x << 6);
padding++;
}
else {
p = base64;
while(*p && (*p != *s)) {
v++;
p++;
}
if(*p == *s)
x = (x << 6) + v;
else
return 0;
}
}
if(padding < 1)
dest[2] = curlx_ultouc(x & 0xFFUL);
x >>= 8;
if(padding < 2)
dest[1] = curlx_ultouc(x & 0xFFUL);
x >>= 8;
dest[0] = curlx_ultouc(x & 0xFFUL);
return 3 - padding;
}
/*
* Curl_base64_decode()
*
* Given a base64 NUL-terminated string at src, decode it and return a
* pointer in *outptr to a newly allocated memory area holding decoded
* data. Size of decoded data is returned in variable pointed by outlen.
*
* Returns CURLE_OK on success, otherwise specific error code. Function
* output shall not be considered valid unless CURLE_OK is returned.
*
* When decoded data length is 0, returns NULL in *outptr.
*
* @unittest: 1302
*/
CURLcode Curl_base64_decode(const char *src,
unsigned char **outptr, size_t *outlen)
{
size_t srclen = 0;
size_t length = 0;
size_t padding = 0;
size_t i;
size_t numQuantums;
size_t rawlen = 0;
unsigned char *pos;
unsigned char *newstr;
*outptr = NULL;
*outlen = 0;
srclen = strlen(src);
/* Check the length of the input string is valid */
if(!srclen || srclen % 4)
return CURLE_BAD_CONTENT_ENCODING;
/* Find the position of any = padding characters */
while((src[length] != '=') && src[length])
length++;
/* A maximum of two = padding characters is allowed */
if(src[length] == '=') {
padding++;
if(src[length + 1] == '=')
padding++;
}
/* Check the = padding characters weren't part way through the input */
if(length + padding != srclen)
return CURLE_BAD_CONTENT_ENCODING;
/* Calculate the number of quantums */
numQuantums = srclen / 4;
/* Calculate the size of the decoded string */
rawlen = (numQuantums * 3) - padding;
/* Allocate our buffer including room for a zero terminator */
newstr = malloc(rawlen + 1);
if(!newstr)
return CURLE_OUT_OF_MEMORY;
pos = newstr;
/* Decode the quantums */
for(i = 0; i < numQuantums; i++) {
size_t result = decodeQuantum(pos, src);
if(!result) {
free(newstr);
return CURLE_BAD_CONTENT_ENCODING;
}
pos += result;
src += 4;
}
/* Zero terminate */
*pos = '\0';
/* Return the decoded data */
*outptr = newstr;
*outlen = rawlen;
return CURLE_OK;
}
static CURLcode base64_encode(const char *table64,
struct Curl_easy *data,
const char *inputbuff, size_t insize,
char **outptr, size_t *outlen)
{
CURLcode result;
unsigned char ibuf[3];
unsigned char obuf[4];
int i;
int inputparts;
char *output;
char *base64data;
char *convbuf = NULL;
const char *indata = inputbuff;
*outptr = NULL;
*outlen = 0;
if(!insize)
insize = strlen(indata);
#if SIZEOF_SIZE_T == 4
if(insize > UINT_MAX/4)
return CURLE_OUT_OF_MEMORY;
#endif
base64data = output = malloc(insize * 4 / 3 + 4);
if(!output)
return CURLE_OUT_OF_MEMORY;
/*
* The base64 data needs to be created using the network encoding
* not the host encoding. And we can't change the actual input
* so we copy it to a buffer, translate it, and use that instead.
*/
result = Curl_convert_clone(data, indata, insize, &convbuf);
if(result) {
free(output);
return result;
}
if(convbuf)
indata = (char *)convbuf;
while(insize > 0) {
for(i = inputparts = 0; i < 3; i++) {
if(insize > 0) {
inputparts++;
ibuf[i] = (unsigned char) *indata;
indata++;
insize--;
}
else
ibuf[i] = 0;
}
obuf[0] = (unsigned char) ((ibuf[0] & 0xFC) >> 2);
obuf[1] = (unsigned char) (((ibuf[0] & 0x03) << 4) | \
((ibuf[1] & 0xF0) >> 4));
obuf[2] = (unsigned char) (((ibuf[1] & 0x0F) << 2) | \
((ibuf[2] & 0xC0) >> 6));
obuf[3] = (unsigned char) (ibuf[2] & 0x3F);
switch(inputparts) {
case 1: /* only one byte read */
snprintf(output, 5, "%c%c==",
table64[obuf[0]],
table64[obuf[1]]);
break;
case 2: /* two bytes read */
snprintf(output, 5, "%c%c%c=",
table64[obuf[0]],
table64[obuf[1]],
table64[obuf[2]]);
break;
default:
snprintf(output, 5, "%c%c%c%c",
table64[obuf[0]],
table64[obuf[1]],
table64[obuf[2]],
table64[obuf[3]]);
break;
}
output += 4;
}
/* Zero terminate */
*output = '\0';
/* Return the pointer to the new data (allocated memory) */
*outptr = base64data;
free(convbuf);
/* Return the length of the new data */
*outlen = strlen(base64data);
return CURLE_OK;
}
/*
* Curl_base64_encode()
*
* Given a pointer to an input buffer and an input size, encode it and
* return a pointer in *outptr to a newly allocated memory area holding
* encoded data. Size of encoded data is returned in variable pointed by
* outlen.
*
* Input length of 0 indicates input buffer holds a NUL-terminated string.
*
* Returns CURLE_OK on success, otherwise specific error code. Function
* output shall not be considered valid unless CURLE_OK is returned.
*
* When encoded data length is 0, returns NULL in *outptr.
*
* @unittest: 1302
*/
CURLcode Curl_base64_encode(struct Curl_easy *data,
const char *inputbuff, size_t insize,
char **outptr, size_t *outlen)
{
return base64_encode(base64, data, inputbuff, insize, outptr, outlen);
}
/*
* Curl_base64url_encode()
*
* Given a pointer to an input buffer and an input size, encode it and
* return a pointer in *outptr to a newly allocated memory area holding
* encoded data. Size of encoded data is returned in variable pointed by
* outlen.
*
* Input length of 0 indicates input buffer holds a NUL-terminated string.
*
* Returns CURLE_OK on success, otherwise specific error code. Function
* output shall not be considered valid unless CURLE_OK is returned.
*
* When encoded data length is 0, returns NULL in *outptr.
*
* @unittest: 1302
*/
CURLcode Curl_base64url_encode(struct Curl_easy *data,
const char *inputbuff, size_t insize,
char **outptr, size_t *outlen)
{
return base64_encode(base64url, data, inputbuff, insize, outptr, outlen);
}