Restructured the RNG source and add support for loadable

random modules.

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
+