diff options
Diffstat (limited to 'cipher/rndegd.c')
| -rw-r--r-- | cipher/rndegd.c | 225 |
1 files changed, 225 insertions, 0 deletions
diff --git a/cipher/rndegd.c b/cipher/rndegd.c new file mode 100644 index 0000000..e6646a2 --- /dev/null +++ b/cipher/rndegd.c @@ -0,0 +1,225 @@ +/* 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 2 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, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, + * USA. + */ + +#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 */ +} |