Restructured the RNG source and add support for loadable

random modules.

1 files changed, 136 insertions, 7 deletions

diff --git a/cipher/random.c b/cipher/random.c
index e22f3d70c..e173a5279 100644
--- a/cipher/random.c
+++ b/cipher/random.c
@@ -36,7 +36,9 @@
 #include "rmd.h"
 #include "ttyio.h"
 #include "i18n.h"
+#include "random.h"
 #include "rand-internal.h"
+#include "dynload.h"
 
 
 #if SIZEOF_UNSIGNED_LONG == 8
@@ -47,6 +49,20 @@
   #error weird size for an unsigned long
 #endif
 
+#define BLOCKLEN  64   /* hash this amount of bytes */
+#define DIGESTLEN 20   /* into a digest of this length (rmd160) */
+/* poolblocks is the number of digests which make up the pool
+ * and poolsize must be a multiple of the digest length
+ * to make the AND operations faster, the size should also be
+ * a multiple of ulong
+ */
+#define POOLBLOCKS 30
+#define POOLSIZE (POOLBLOCKS*DIGESTLEN)
+#if (POOLSIZE % SIZEOF_UNSIGNED_LONG)
+  #error Please make sure that poolsize is a multiple of ulong
+#endif
+#define POOLWORDS (POOLSIZE / SIZEOF_UNSIGNED_LONG)
+
 
 static int is_initialized;
 #define MASK_LEVEL(a) do {if( a > 2 ) a = 2; else if( a < 0 ) a = 0; } while(0)
@@ -60,9 +76,16 @@ static int just_mixed;
 
 static int secure_alloc;
 static int quick_test;
+static int faked_rng;
 
 
 static void read_pool( byte *buffer, size_t length, int level );
+static void add_randomness( const void *buffer, size_t length, int source );
+static void random_poll(void);
+static void read_random_source( byte *buffer, size_t length, int level );
+#ifndef HAVE_DEV_RANDOM
+static int gather_faked( byte *buffer, size_t *r_length, int level );
+#endif
 
 
 static void
@@ -76,6 +99,20 @@ initialize()
     keypool = secure_alloc ? m_alloc_secure_clear(POOLSIZE+BLOCKLEN)
 			   : m_alloc_clear(POOLSIZE+BLOCKLEN);
     is_initialized = 1;
+
+  #if	USE_RNDLINUX
+    rndlinux_constructor();
+  #elif USE_RNDUNIX
+    rndunix_constructor();
+  #elif USE_RNDW32
+    rndw32_constructor();
+  #elif USE_RNDOS2
+    rndos2_constructor();
+  #elif USE_RNDATARI
+    rndatari_constructor();
+  #elif USE_RNDMVS
+    rndmvs_constructor();
+  #endif
 }
 
 void
@@ -88,13 +125,13 @@ secure_random_alloc()
 int
 quick_random_gen( int onoff )
 {
-    int last = quick_test;
+    int last;
+
+    read_random_source( NULL, 0, 0 ); /* load module */
+    last = quick_test;
     if( onoff != -1 )
 	quick_test = onoff;
-  #ifdef USE_RAND_DUMMY
-    last = 1; /* insecure RNG */
-  #endif
-    return last;
+    return faked_rng? 1 : last;
 }
 
 
@@ -250,9 +287,9 @@ read_pool( byte *buffer, size_t length, int level )
 
 /****************
  * Add LENGTH bytes of randomness from buffer to the pool.
- * source may be used to specify the randomeness source.
+ * source may be used to specify the randomness source.
  */
-void
+static void
 add_randomness( const void *buffer, size_t length, int source )
 {
     if( !is_initialized )
@@ -271,3 +308,95 @@ add_randomness( const void *buffer, size_t length, int source )
 
 
 
+static void
+random_poll()
+{
+    char buf[POOLSIZE/5];
+    read_random_source( buf, POOLSIZE/5, 1 );
+    add_randomness( buf, POOLSIZE/5, 2);
+    memset( buf, 0, POOLSIZE/5);
+}
+
+
+void
+fast_random_poll()
+{
+    static void (*fnc)( void (*)(const void*, size_t, int)) = NULL;
+    static int initialized = 0;
+
+    if( !initialized ) {
+	if( !is_initialized )
+	    initialize();
+	initialized = 1;
+	fnc = dynload_getfnc_fast_random_poll();
+	if( !fnc )
+	    log_info("Ooops: No fast random poll function\n");
+    }
+    if( fnc )
+	(*fnc)( add_randomness );
+}
+
+
+
+static void
+read_random_source( byte *buffer, size_t length, int level )
+{
+    static int (*fnc)(byte*, size_t*, int) = NULL;
+    int nbytes;
+    int goodness;
+
+    if( !fnc ) {
+	if( !is_initialized )
+	    initialize();
+	fnc = dynload_getfnc_gather_random();
+	if( !fnc ) {
+	    faked_rng = 1;
+	  #ifndef HAVE_DEV_RANDOM
+	    fnc = gather_faked;
+	  #else
+	    BUG();
+	  #endif
+	}
+    }
+    while( length ) {
+	nbytes = length;
+	goodness = (*fnc)( buffer, &nbytes, level );
+	buffer +=nbytes;
+	length -= nbytes;
+	/* FIXME: how can we handle the goodness */
+    }
+}
+
+
+#ifndef HAVE_DEV_RANDOM
+static int
+gather_faked( byte *buffer, size_t *r_length, int level )
+{
+    static int initialized=0;
+    size_t length = *r_length;
+
+    if( !initialized ) {
+	log_info(_("WARNING: using insecure random number generator!!\n"));
+	tty_printf(_("The random number generator is only a kludge to let\n"
+		   "it compile - it is in no way a strong RNG!\n\n"
+		   "DON'T USE ANY DATA GENERATED BY THIS PROGRAM!!\n\n"));
+	initialized=1;
+      #ifdef HAVE_RAND
+	srand(make_timestamp()*getpid());
+      #else
+	srandom(make_timestamp()*getpid());
+      #endif
+    }
+
+  #ifdef HAVE_RAND
+    while( length-- )
+	*buffer++ = ((unsigned)(1 + (int) (256.0*rand()/(RAND_MAX+1.0)))-1);
+  #else
+    while( length-- )
+	*buffer++ = ((unsigned)(1 + (int) (256.0*random()/(RAND_MAX+1.0)))-1);
+  #endif
+    return 100; /* We really fake it ;-) */
+}
+
+#endif /* ! HAVE_DEV_RANDOM */
+