Page MenuHome GnuPG
Files F34606899

rndegd.c
No OneTemporary
Actions

rndegd.c
View Options

/* rndegd.c - interface to the EGD
* Copyright (C) 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
*
* This file is part of GnuPG.
*
* GnuPG 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.
*
* GnuPG 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 <http://www.gnu.org/licenses/>.
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <errno.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include "types.h"
#include "util.h"
#include "ttyio.h"
#include "algorithms.h"
#include "cipher.h"
#include "i18n.h"
#ifndef offsetof
#define offsetof(type, member) ((size_t) &((type *)0)->member)
#endif
static int egd_socket = -1;
static int
do_write( int fd, void *buf, size_t nbytes )
{
size_t nleft = nbytes;
int nwritten;
while( nleft > 0 ) {
nwritten = write( fd, buf, nleft);
if( nwritten < 0 ) {
if( errno == EINTR )
continue;
return -1;
}
nleft -= nwritten;
buf = (char*)buf + nwritten;
}
return 0;
}
static int
do_read( int fd, void *buf, size_t nbytes )
{
int n, nread = 0;
while (nbytes)
{
do {
n = read(fd, (char*)buf + nread, nbytes );
} while( n == -1 && errno == EINTR );
if( n == -1 )
return nread? nread:-1;
else if( n == 0 ) {
/* EGD probably died. */
errno = ECONNRESET;
return -1;
}
nread += n;
nbytes -= n;
}
return nread;
}
/* Connect to the EGD and return the file descriptor. Return -1 on
error. With NOFAIL set to true, silently fail and return the
error, otherwise print an error message and die. */
int
rndegd_connect_socket (int nofail)
{
int fd;
const char *bname = NULL;
char *name;
struct sockaddr_un addr;
int addr_len;
if (egd_socket != -1)
{
close (egd_socket);
egd_socket = -1;
}
#ifdef EGD_SOCKET_NAME
bname = EGD_SOCKET_NAME;
#endif
if ( !bname || !*bname )
bname = "=entropy";
if ( *bname == '=' && bname[1] )
name = make_filename( g10_opt_homedir, bname+1 , NULL );
else
name = make_filename( bname , NULL );
if ( strlen(name)+1 >= sizeof addr.sun_path )
g10_log_fatal ("EGD socketname is too long\n");
memset( &addr, 0, sizeof addr );
addr.sun_family = AF_UNIX;
strcpy( addr.sun_path, name );
addr_len = (offsetof( struct sockaddr_un, sun_path )
+ strlen( addr.sun_path ));
fd = socket(AF_UNIX, SOCK_STREAM, 0);
if (fd == -1 && !nofail)
g10_log_fatal("can't create unix domain socket: %s\n",
strerror(errno) );
else if (connect (fd, (struct sockaddr*)&addr, addr_len) == -1)
{
if (!nofail)
g10_log_fatal("can't connect to `%s': %s\n",
name, strerror(errno) );
close (fd);
fd = -1;
}
xfree(name);
if (fd != -1)
egd_socket = fd;
return fd;
}
/****************
* Note: we always use the highest level.
* TO boost the performance we may want to add some
* additional code for level 1
*
* Using a level of 0 should never block and better add nothing
* to the pool. So this is just a dummy for EGD.
*/
int
rndegd_gather_random( void (*add)(const void*, size_t, int), int requester,
size_t length, int level )
{
int fd = egd_socket;
int n;
byte buffer[256+2];
int nbytes;
int do_restart = 0;
if( !length )
return 0;
if( !level )
return 0;
restart:
if (fd == -1 || do_restart)
fd = rndegd_connect_socket (0);
do_restart = 0;
nbytes = length < 255? length : 255;
/* first time we do it with a non blocking request */
buffer[0] = 1; /* non blocking */
buffer[1] = nbytes;
if( do_write( fd, buffer, 2 ) == -1 )
g10_log_fatal("can't write to the EGD: %s\n", strerror(errno) );
n = do_read( fd, buffer, 1 );
if( n == -1 ) {
g10_log_error("read error on EGD: %s\n", strerror(errno));
do_restart = 1;
goto restart;
}
n = buffer[0];
if( n ) {
n = do_read( fd, buffer, n );
if( n == -1 ) {
g10_log_error("read error on EGD: %s\n", strerror(errno));
do_restart = 1;
goto restart;
}
(*add)( buffer, n, requester );
length -= n;
}
if( length ) {
tty_printf(
_("Please wait, entropy is being gathered. Do some work if it would\n"
"keep you from getting bored, because it will improve the quality\n"
"of the entropy.\n") );
}
while( length ) {
nbytes = length < 255? length : 255;
buffer[0] = 2; /* blocking */
buffer[1] = nbytes;
if( do_write( fd, buffer, 2 ) == -1 )
g10_log_fatal("can't write to the EGD: %s\n", strerror(errno) );
n = do_read( fd, buffer, nbytes );
if( n == -1 ) {
g10_log_error("read error on EGD: %s\n", strerror(errno));
do_restart = 1;
goto restart;
}
(*add)( buffer, n, requester );
length -= n;
}
wipememory(buffer, sizeof(buffer) );
return 0; /* success */
}

File Metadata

Mime Type
text/x-c
Expires
Sun, Jan 18, 11:22 PM (3 h, 39 m)
Storage Engine
local-disk
Storage Format
Raw Data
Storage Handle
71/b0/42ed5095cf356c924e558d18d013

Event Timeline