1
0
mirror of git://git.gnupg.org/gnupg.git synced 2024-12-23 10:29:58 +01:00
gnupg/common/percent.c
Werner Koch 055f8854d3
common: Extend function percent_data_escape.
* common/percent.c (percent_data_escape): Add new args prefix and
plus_escape.
* agent/command.c (cmd_put_secret): Adjust for changed function

* common/t-percent.c (test_percent_data_escape): Extend test for the
prefix.
(test_percent_data_escape_plus): new test for the plus escaping.

Signed-off-by: Werner Koch <wk@gnupg.org>
2019-01-24 10:02:52 +01:00

322 lines
7.7 KiB
C

/* percent.c - Percent escaping
* Copyright (C) 2008, 2009 Free Software Foundation, Inc.
*
* This file is part of GnuPG.
*
* This file is free software; you can redistribute it and/or modify
* it under the terms of either
*
* - the GNU Lesser General Public License as published by the Free
* Software Foundation; either version 3 of the License, or (at
* your option) any later version.
*
* or
*
* - 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.
*
* or both in parallel, as here.
*
* This file is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <https://www.gnu.org/licenses/>.
*/
#include <config.h>
#include <stdlib.h>
#include <errno.h>
#include <ctype.h>
#include <assert.h>
#include "util.h"
/* Create a newly alloced string from STRING with all spaces and
* control characters converted to plus signs or %xx sequences. The
* function returns the new string or NULL in case of a malloc
* failure.
*
* Note that this fucntion also escapes the quote character to work
* around a bug in the mingw32 runtime which does not correctly handle
* command line quoting. We correctly double the quote mark when
* calling a program (i.e. gpg-protect-tool), but the pre-main code
* does not notice the double quote as an escaped quote. We do this
* also on POSIX systems for consistency. */
char *
percent_plus_escape (const char *string)
{
char *buffer, *p;
const char *s;
size_t length;
for (length=1, s=string; *s; s++)
{
if (*s == '+' || *s == '\"' || *s == '%'
|| *(const unsigned char *)s < 0x20)
length += 3;
else
length++;
}
buffer = p = xtrymalloc (length);
if (!buffer)
return NULL;
for (s=string; *s; s++)
{
if (*s == '+' || *s == '\"' || *s == '%'
|| *(const unsigned char *)s < 0x20)
{
snprintf (p, 4, "%%%02X", *(unsigned char *)s);
p += 3;
}
else if (*s == ' ')
*p++ = '+';
else
*p++ = *s;
}
*p = 0;
return buffer;
}
/* Create a newly malloced string from (DATA,DATALEN) with embedded
* nuls quoted as %00. The standard percent unescaping can be used to
* reverse this encoding. With PLUS_ESCAPE set plus-escaping (spaces
* are replaced by a '+') and escaping of characters with values less
* than 0x20 is used. If PREFIX is not NULL it will be prepended to
* the output in standard escape format; that is PLUS_ESCAPING is
* ignored for PREFIX. */
char *
percent_data_escape (int plus_escape, const char *prefix,
const void *data, size_t datalen)
{
char *buffer, *p;
const unsigned char *s;
size_t n;
size_t length = 1;
if (prefix)
{
for (s = prefix; *s; s++)
{
if (*s == '%' || *s < 0x20)
length += 3;
else
length++;
}
}
for (s=data, n=datalen; n; s++, n--)
{
if (!*s || *s == '%' || (plus_escape && (*s < ' ' || *s == '+')))
length += 3;
else
length++;
}
buffer = p = xtrymalloc (length);
if (!buffer)
return NULL;
if (prefix)
{
for (s = prefix; *s; s++)
{
if (*s == '%' || *s < 0x20)
{
snprintf (p, 4, "%%%02X", *s);
p += 3;
}
else
*p++ = *s;
}
}
for (s=data, n=datalen; n; s++, n--)
{
if (!*s)
{
memcpy (p, "%00", 3);
p += 3;
}
else if (*s == '%')
{
memcpy (p, "%25", 3);
p += 3;
}
else if (plus_escape && *s == ' ')
{
*p++ = '+';
}
else if (plus_escape && (*s < ' ' || *s == '+'))
{
snprintf (p, 4, "%%%02X", *s);
p += 3;
}
else
*p++ = *s;
}
*p = 0;
return buffer;
}
/* Do the percent and plus/space unescaping from STRING to BUFFER and
return the length of the valid buffer. Plus unescaping is only
done if WITHPLUS is true. An escaped Nul character will be
replaced by NULREPL. */
static size_t
do_unescape (unsigned char *buffer, const unsigned char *string,
int withplus, int nulrepl)
{
unsigned char *p = buffer;
while (*string)
{
if (*string == '%' && string[1] && string[2])
{
string++;
*p = xtoi_2 (string);
if (!*p)
*p = nulrepl;
string++;
}
else if (*string == '+' && withplus)
*p = ' ';
else
*p = *string;
p++;
string++;
}
return (p - buffer);
}
/* Count space required after unescaping STRING. Note that this will
never be larger than strlen (STRING). */
static size_t
count_unescape (const unsigned char *string)
{
size_t n = 0;
while (*string)
{
if (*string == '%' && string[1] && string[2])
{
string++;
string++;
}
string++;
n++;
}
return n;
}
/* Helper. */
static char *
do_plus_or_plain_unescape (const char *string, int withplus, int nulrepl)
{
size_t nbytes, n;
char *newstring;
nbytes = count_unescape (string);
newstring = xtrymalloc (nbytes+1);
if (newstring)
{
n = do_unescape (newstring, string, withplus, nulrepl);
assert (n == nbytes);
newstring[n] = 0;
}
return newstring;
}
/* Create a new allocated string from STRING with all "%xx" sequences
decoded and all plus signs replaced by a space. Embedded Nul
characters are replaced by the value of NULREPL. The function
returns the new string or NULL in case of a malloc failure. */
char *
percent_plus_unescape (const char *string, int nulrepl)
{
return do_plus_or_plain_unescape (string, 1, nulrepl);
}
/* Create a new allocated string from STRING with all "%xx" sequences
decoded. Embedded Nul characters are replaced by the value of
NULREPL. The function returns the new string or NULL in case of a
malloc failure. */
char *
percent_unescape (const char *string, int nulrepl)
{
return do_plus_or_plain_unescape (string, 0, nulrepl);
}
static size_t
do_unescape_inplace (char *string, int withplus, int nulrepl)
{
unsigned char *p, *p0;
p = p0 = string;
while (*string)
{
if (*string == '%' && string[1] && string[2])
{
string++;
*p = xtoi_2 (string);
if (!*p)
*p = nulrepl;
string++;
}
else if (*string == '+' && withplus)
*p = ' ';
else
*p = *string;
p++;
string++;
}
return (p - p0);
}
/* Perform percent and plus unescaping in STRING and return the new
valid length of the string. Embedded Nul characters are replaced
by the value of NULREPL. A terminating Nul character is not
inserted; the caller might want to call this function this way:
foo[percent_plus_unescape_inplace (foo, 0)] = 0;
*/
size_t
percent_plus_unescape_inplace (char *string, int nulrepl)
{
return do_unescape_inplace (string, 1, nulrepl);
}
/* Perform percent unescaping in STRING and return the new valid
length of the string. Embedded Nul characters are replaced by the
value of NULREPL. A terminating Nul character is not inserted; the
caller might want to call this function this way:
foo[percent_unescape_inplace (foo, 0)] = 0;
*/
size_t
percent_unescape_inplace (char *string, int nulrepl)
{
return do_unescape_inplace (string, 0, nulrepl);
}