pidgin/pidgin

certificate: Use SHA256 fingerprints instead of SHA1
release-2.x.y
2017-03-06, dx
b3d0ba7c75f6
certificate: Use SHA256 fingerprints instead of SHA1

This meant adding a get_fingerprint_sha256 function to the certificate scheme
structs, which meant adding a struct_size member because we ran out of reserved
members there.

The API-facing purple_certificate_get_fingerprint_sha256() has a fallback
parameter to use sha1 if the SSL plugin doesn't implement this function
(probably an outdated installation, or a third party SSL plugin). When using
the function for display purposes, the fallback is disabled and it returns
NULL, but when using it to compare certificates it's better to have at least
the SHA1.

In functions like purple_certificate_display_x509(), some slight changes to
translatable strings would have been required. Since we're in a string freeze
right now, I avoided those by concatenating a language-neutral "SHA256: %s" at
the end of those messages. The SHA1 line used the word "fingerprint" but we
can't reuse that translation. This should be cleaned up after the release.
/**
* @file stringref.c Reference-counted immutable strings
* @ingroup core
*/
/* purple
*
* Purple is the legal property of its developers, whose names are too numerous
* to list here. Please refer to the COPYRIGHT file distributed with this
* source distribution.
*
* 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 2 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, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111-1301 USA
*
*/
#include "internal.h"
#include <string.h>
#include <stdarg.h>
#include "debug.h"
#include "eventloop.h"
#include "stringref.h"
/**
* The internal representation of a stringref.
*
* @note For this structure to be useful, the string contained within
* it must be immutable -- for this reason, do _not_ access it
* directly!
*/
struct _PurpleStringref {
guint32 ref; /**< The reference count of this string.
* Note that reference counts are only
* 31 bits, and the high-order bit
* indicates whether this string is up
* for GC at the next idle handler...
* But you aren't going to touch this
* anyway, right? */
char value[1]; /**< The string contained in this ref.
* Notice that it is simply "hanging
* off the end" of the ref ... this
* is to save an allocation. */
};
#define REFCOUNT(x) ((x) & 0x7fffffff)
static GList *gclist = NULL;
static void stringref_free(PurpleStringref *stringref);
static gboolean gs_idle_cb(gpointer data);
PurpleStringref *purple_stringref_new(const char *value)
{
PurpleStringref *newref;
size_t len;
if (value == NULL)
return NULL;
len = strlen(value);
newref = g_malloc(sizeof(PurpleStringref) + len);
/* g_strlcpy() takes the size of the buffer, including the NUL.
strlen() returns the length of the string, without the NUL. */
g_strlcpy(newref->value, value, len + 1);
newref->ref = 1;
return newref;
}
PurpleStringref *purple_stringref_new_noref(const char *value)
{
PurpleStringref *newref;
if (value == NULL)
return NULL;
newref = g_malloc(sizeof(PurpleStringref) + strlen(value));
strcpy(newref->value, value);
newref->ref = 0x80000000;
if (gclist == NULL)
purple_timeout_add(0, gs_idle_cb, NULL);
gclist = g_list_prepend(gclist, newref);
return newref;
}
PurpleStringref *purple_stringref_printf(const char *format, ...)
{
PurpleStringref *newref;
va_list ap;
if (format == NULL)
return NULL;
va_start(ap, format);
newref = g_malloc(sizeof(PurpleStringref) + g_printf_string_upper_bound(format, ap));
vsprintf(newref->value, format, ap);
va_end(ap);
newref->ref = 1;
return newref;
}
PurpleStringref *purple_stringref_ref(PurpleStringref *stringref)
{
if (stringref == NULL)
return NULL;
stringref->ref++;
return stringref;
}
void purple_stringref_unref(PurpleStringref *stringref)
{
if (stringref == NULL)
return;
if (REFCOUNT(--(stringref->ref)) == 0) {
if (stringref->ref & 0x80000000)
gclist = g_list_remove(gclist, stringref);
stringref_free(stringref);
}
}
const char *purple_stringref_value(const PurpleStringref *stringref)
{
return (stringref == NULL ? NULL : stringref->value);
}
int purple_stringref_cmp(const PurpleStringref *s1, const PurpleStringref *s2)
{
return (s1 == s2 ? 0 : strcmp(purple_stringref_value(s1), purple_stringref_value(s2)));
}
size_t purple_stringref_len(const PurpleStringref *stringref)
{
return strlen(purple_stringref_value(stringref));
}
static void stringref_free(PurpleStringref *stringref)
{
#ifdef DEBUG
if (REFCOUNT(stringref->ref) != 0) {
purple_debug(PURPLE_DEBUG_ERROR, "stringref", "Free of nonzero (%d) ref stringref!\n", REFCOUNT(stringref->ref));
return;
}
#endif /* DEBUG */
g_free(stringref);
}
static gboolean gs_idle_cb(gpointer data)
{
PurpleStringref *ref;
GList *del;
while (gclist != NULL) {
ref = gclist->data;
if (REFCOUNT(ref->ref) == 0) {
stringref_free(ref);
}
del = gclist;
gclist = gclist->next;
g_list_free_1(del);
}
return FALSE;
}