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/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 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.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.
*
* SPDX-License-Identifier: curl
*
***************************************************************************/
/* Escape and unescape URL encoding in strings. The functions return a new
* allocated string or NULL if an error occurred. */
#include "curl_setup.h"
#include <curl/curl.h>
#include "urldata.h"
#include "warnless.h"
#include "escape.h"
#include "strdup.h"
/* The last 3 #include files should be in this order */
#include "curl_printf.h"
#include "curl_memory.h"
#include "memdebug.h"
/* for ABI-compatibility with previous versions */
char *curl_escape(const char *string, int inlength)
{
return curl_easy_escape(NULL, string, inlength);
}
/* for ABI-compatibility with previous versions */
char *curl_unescape(const char *string, int length)
{
return curl_easy_unescape(NULL, string, length, NULL);
}
/* Escapes for URL the given unescaped string of given length.
* 'data' is ignored since 7.82.0.
*/
char *curl_easy_escape(struct Curl_easy *data, const char *string,
int inlength)
{
size_t length;
struct dynbuf d;
(void)data;
if(!string || (inlength < 0))
return NULL;
length = (inlength?(size_t)inlength:strlen(string));
if(!length)
return strdup("");
Curl_dyn_init(&d, length * 3 + 1);
while(length--) {
/* treat the characters unsigned */
unsigned char in = (unsigned char)*string++;
if(ISUNRESERVED(in)) {
/* append this */
if(Curl_dyn_addn(&d, &in, 1))
return NULL;
}
else {
/* encode it */
const char hex[] = "0123456789ABCDEF";
char out[3]={'%'};
out[1] = hex[in>>4];
out[2] = hex[in & 0xf];
if(Curl_dyn_addn(&d, out, 3))
return NULL;
}
}
return Curl_dyn_ptr(&d);
}
static const unsigned char hextable[] = {
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 0, 0, 0, 0, 0, /* 0x30 - 0x3f */
0, 10, 11, 12, 13, 14, 15, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 0x40 - 0x4f */
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 0x50 - 0x5f */
0, 10, 11, 12, 13, 14, 15 /* 0x60 - 0x66 */
};
/* the input is a single hex digit */
#define onehex2dec(x) hextable[x - '0']
/*
* Curl_urldecode() URL decodes the given string.
*
* Returns a pointer to a malloced string in *ostring with length given in
* *olen. If length == 0, the length is assumed to be strlen(string).
*
* ctrl options:
* - REJECT_NADA: accept everything
* - REJECT_CTRL: rejects control characters (byte codes lower than 32) in
* the data
* - REJECT_ZERO: rejects decoded zero bytes
*
* The values for the enum starts at 2, to make the assert detect legacy
* invokes that used TRUE/FALSE (0 and 1).
*/
CURLcode Curl_urldecode(const char *string, size_t length,
char **ostring, size_t *olen,
enum urlreject ctrl)
{
size_t alloc;
char *ns;
DEBUGASSERT(string);
DEBUGASSERT(ctrl >= REJECT_NADA); /* crash on TRUE/FALSE */
alloc = (length?length:strlen(string));
ns = malloc(alloc + 1);
if(!ns)
return CURLE_OUT_OF_MEMORY;
/* store output string */
*ostring = ns;
while(alloc) {
unsigned char in = (unsigned char)*string;
if(('%' == in) && (alloc > 2) &&
ISXDIGIT(string[1]) && ISXDIGIT(string[2])) {
/* this is two hexadecimal digits following a '%' */
in = (unsigned char)(onehex2dec(string[1]) << 4) | onehex2dec(string[2]);
string += 3;
alloc -= 3;
}
else {
string++;
alloc--;
}
if(((ctrl == REJECT_CTRL) && (in < 0x20)) ||
((ctrl == REJECT_ZERO) && (in == 0))) {
Curl_safefree(*ostring);
return CURLE_URL_MALFORMAT;
}
*ns++ = (char)in;
}
*ns = 0; /* terminate it */
if(olen)
/* store output size */
*olen = ns - *ostring;
return CURLE_OK;
}
/*
* Unescapes the given URL escaped string of given length. Returns a
* pointer to a malloced string with length given in *olen.
* If length == 0, the length is assumed to be strlen(string).
* If olen == NULL, no output length is stored.
* 'data' is ignored since 7.82.0.
*/
char *curl_easy_unescape(struct Curl_easy *data, const char *string,
int length, int *olen)
{
char *str = NULL;
(void)data;
if(string && (length >= 0)) {
size_t inputlen = (size_t)length;
size_t outputlen;
CURLcode res = Curl_urldecode(string, inputlen, &str, &outputlen,
REJECT_NADA);
if(res)
return NULL;
if(olen) {
if(outputlen <= (size_t) INT_MAX)
*olen = curlx_uztosi(outputlen);
else
/* too large to return in an int, fail! */
Curl_safefree(str);
}
}
return str;
}
/* For operating systems/environments that use different malloc/free
systems for the app and for this library, we provide a free that uses
the library's memory system */
void curl_free(void *p)
{
free(p);
}
/*
* Curl_hexencode()
*
* Converts binary input to lowercase hex-encoded ASCII output.
* Null-terminated.
*/
void Curl_hexencode(const unsigned char *src, size_t len, /* input length */
unsigned char *out, size_t olen) /* output buffer size */
{
const char *hex = "0123456789abcdef";
DEBUGASSERT(src && len && (olen >= 3));
if(src && len && (olen >= 3)) {
while(len-- && (olen >= 3)) {
/* clang-tidy warns on this line without this comment: */
/* NOLINTNEXTLINE(clang-analyzer-core.UndefinedBinaryOperatorResult) */
*out++ = (unsigned char)hex[(*src & 0xF0)>>4];
*out++ = (unsigned char)hex[*src & 0x0F];
++src;
olen -= 2;
}
*out = 0;
}
else if(olen)
*out = 0;
}
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