notmuch/util/hex-escape.c
Daniel Kahn Gillmor 6a833a6e83 Use https instead of http where possible
Many of the external links found in the notmuch source can be resolved
using https instead of http.  This changeset addresses as many as i
could find, without touching the e-mail corpus or expected outputs
found in tests.
2016-06-05 08:32:17 -03:00

159 lines
3.5 KiB
C

/* hex-escape.c - Manage encoding and decoding of byte strings into path names
*
* Copyright (c) 2011 David Bremner
*
* 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 3 of the License, or
* (at your option) any later version.
*
* This program 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/ .
*
* Author: David Bremner <david@tethera.net>
*/
#include <assert.h>
#include <string.h>
#include <talloc.h>
#include <ctype.h>
#include "error_util.h"
#include "hex-escape.h"
static const char *output_charset =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+-_@=.,";
static const char escape_char = '%';
static int
is_output (char c)
{
return (strchr (output_charset, c) != NULL);
}
static int
maybe_realloc (void *ctx, size_t needed, char **out, size_t *out_size)
{
if (*out_size < needed) {
if (*out == NULL)
*out = talloc_size (ctx, needed);
else
*out = talloc_realloc (ctx, *out, char, needed);
if (*out == NULL)
return 0;
*out_size = needed;
}
return 1;
}
hex_status_t
hex_encode (void *ctx, const char *in, char **out, size_t *out_size)
{
const char *p;
char *q;
size_t needed = 1; /* for the NUL */
assert (ctx); assert (in); assert (out); assert (out_size);
for (p = in; *p; p++) {
needed += is_output (*p) ? 1 : 3;
}
if (*out == NULL)
*out_size = 0;
if (!maybe_realloc (ctx, needed, out, out_size))
return HEX_OUT_OF_MEMORY;
q = *out;
p = in;
while (*p) {
if (is_output (*p)) {
*q++ = *p++;
} else {
sprintf (q, "%%%02x", (unsigned char)*p++);
q += 3;
}
}
*q = '\0';
return HEX_SUCCESS;
}
/* Hex decode 'in' to 'out'.
*
* This must succeed for in == out to support hex_decode_inplace().
*/
static hex_status_t
hex_decode_internal (const char *in, unsigned char *out)
{
char buf[3];
while (*in) {
if (*in == escape_char) {
char *endp;
/* This also handles unexpected end-of-string. */
if (!isxdigit ((unsigned char) in[1]) ||
!isxdigit ((unsigned char) in[2]))
return HEX_SYNTAX_ERROR;
buf[0] = in[1];
buf[1] = in[2];
buf[2] = '\0';
*out = strtoul (buf, &endp, 16);
if (endp != buf + 2)
return HEX_SYNTAX_ERROR;
in += 3;
out++;
} else {
*out++ = *in++;
}
}
*out = '\0';
return HEX_SUCCESS;
}
hex_status_t
hex_decode_inplace (char *s)
{
/* A decoded string is never longer than the encoded one, so it is
* safe to decode a string onto itself. */
return hex_decode_internal (s, (unsigned char *) s);
}
hex_status_t
hex_decode (void *ctx, const char *in, char **out, size_t * out_size)
{
const char *p;
size_t needed = 1; /* for the NUL */
assert (ctx); assert (in); assert (out); assert (out_size);
for (p = in; *p; p++)
if ((p[0] == escape_char) && isxdigit (p[1]) && isxdigit (p[2]))
needed -= 1;
else
needed += 1;
if (!maybe_realloc (ctx, needed, out, out_size))
return HEX_OUT_OF_MEMORY;
return hex_decode_internal (in, (unsigned char *) *out);
}