diff options
Diffstat (limited to 'cipher/rndlinux.c')
| -rw-r--r-- | cipher/rndlinux.c | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/cipher/rndlinux.c b/cipher/rndlinux.c new file mode 100644 index 000000000..de2710ce5 --- /dev/null +++ b/cipher/rndlinux.c @@ -0,0 +1,237 @@ +/* rndlinux.c - raw random number for OSes with /dev/random + * Copyright (C) 1998 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA + */ + + +#include <config.h> +#include <stdio.h> +#include <stdlib.h> +#include <assert.h> +#include <errno.h> +#include <sys/time.h> +#include <sys/types.h> +#include <sys/stat.h> +#ifdef HAVE_GETHRTIME + #include <sys/times.h> +#endif +#ifdef HAVE_GETTIMEOFDAY + #include <sys/times.h> +#endif +#ifdef HAVE_GETRUSAGE + #include <sys/resource.h> +#endif +#include <string.h> +#include <unistd.h> +#include <fcntl.h> +#include "util.h" +#include "ttyio.h" +#include "i18n.h" + +/* #define IS_MODULE 1 */ + +static int open_device( const char *name, int minor ); +static int gather_random( byte *buffer, size_t *r_length, int level ); + + +static void +fast_poll( void (*add)(const void*, size_t, int) ) +{ + #if HAVE_GETHRTIME + { hrtime_t tv; + tv = gethrtime(); + (*add)( &tv, sizeof(tv), 1 ); + } + #elif HAVE_GETTIMEOFDAY + { struct timeval tv; + if( gettimeofday( &tv, NULL ) ) + BUG(); + (*add)( &tv.tv_sec, sizeof(tv.tv_sec), 1 ); + (*add)( &tv.tv_usec, sizeof(tv.tv_usec), 1 ); + } + #else /* use times */ + { struct tms buf; + times( &buf ); + (*add)( &buf, sizeof buf, 1 ); + } + #endif + #ifdef HAVE_GETRUSAGE + { struct rusage buf; + if( getrusage( RUSAGE_SELF, &buf ) ) + BUG(); + (*add)( &buf, sizeof buf, 1 ); + memset( &buf, 0, sizeof buf ); + } + #endif +} + + + +/**************** + * Used to open the Linux and xBSD /dev/random devices + */ +static int +open_device( const char *name, int minor ) +{ + int fd; + struct stat sb; + + fd = open( name, O_RDONLY ); + if( fd == -1 ) + log_fatal("can't open %s: %s\n", name, strerror(errno) ); + if( fstat( fd, &sb ) ) + log_fatal("stat() off %s failed: %s\n", name, strerror(errno) ); + #if defined(__sparc__) && defined(__linux__) + #warning something is wrong with UltraPenguin /dev/random + #else + if( !S_ISCHR(sb.st_mode) ) + log_fatal("invalid random device!\n" ); + #endif + return fd; +} + + +static int +gather_random( byte *buffer, size_t *r_length, int level ) +{ + static int fd_urandom = -1; + static int fd_random = -1; + int fd; + int n; + int warn=0; + size_t length = *r_length; + /* note: we will always return the requested length */ + + if( level >= 2 ) { + if( fd_random == -1 ) + fd_random = open_device( NAME_OF_DEV_RANDOM, 8 ); + fd = fd_random; + } + else { + if( fd_urandom == -1 ) + fd_urandom = open_device( NAME_OF_DEV_URANDOM, 9 ); + fd = fd_urandom; + } + do { + fd_set rfds; + struct timeval tv; + int rc; + + FD_ZERO(&rfds); + FD_SET(fd, &rfds); + tv.tv_sec = 3; + tv.tv_usec = 0; + if( !(rc=select(fd+1, &rfds, NULL, NULL, &tv)) ) { + if( !warn ) + tty_printf( _( +"\n" +"Not enough random bytes available. Please do some other work to give\n" +"the OS a chance to collect more entropy! (Need %d more bytes)\n"), length ); + warn = 1; + continue; + } + else if( rc == -1 ) { + tty_printf("select() error: %s\n", strerror(errno)); + continue; + } + + do { + n = read(fd, buffer, length ); + if( n >= 0 && n > length ) { + log_error("bogus read from random device (n=%d)\n", n ); + n = length; + } + } while( n == -1 && errno == EINTR ); + if( n == -1 ) + log_fatal("read error on random device: %s\n", strerror(errno) ); + assert( n <= length ); + buffer += n; + length -= n; + } while( length ); + + return 100; /* 100% useful at the requested level */ +} + + + +#ifndef IS_MODULES +static +#endif +const char * const gnupgext_version = "RNDLINUX ($Revision$)"; + +static struct { + int class; + int version; + void *func; +} func_table[] = { + { 40, 1, gather_random }, + { 41, 1, fast_poll }, +}; + + + +/**************** + * Enumerate the names of the functions together with informations about + * this function. Set sequence to an integer with a initial value of 0 and + * do not change it. + * If what is 0 all kind of functions are returned. + * Return values: class := class of function: + * 10 = message digest algorithm info function + * 11 = integer with available md algorithms + * 20 = cipher algorithm info function + * 21 = integer with available cipher algorithms + * 30 = public key algorithm info function + * 31 = integer with available pubkey algorithms + * 40 = get gather_random function + * 41 = get fast_random_poll function + * version = interface version of the function/pointer + * (currently this is 1 for all functions) + */ + +#ifndef IS_MODULE +static +#endif +void * +gnupgext_enum_func( int what, int *sequence, int *class, int *vers ) +{ + void *ret; + int i = *sequence; + + do { + if ( i >= DIM(func_table) || i < 0 ) { + return NULL; + } + *class = func_table[i].class; + *vers = func_table[i].version; + ret = func_table[i].func; + i++; + } while ( what && what != *class ); + + *sequence = i; + return ret; +} + +#ifndef IS_MODULE +void +rndlinux_constructor(void) +{ + register_internal_cipher_extension( gnupgext_version, + gnupgext_enum_func ); +} +#endif + |