Git initHEAD2.0_alphamaster2.0alpha1.0_post

1 files changed, 869 insertions, 0 deletions

diff --git a/cipher/rndunix.c b/cipher/rndunix.c
new file mode 100644
index 0000000..3cc71cf
--- /dev/null
+++ b/cipher/rndunix.c
@@ -0,0 +1,869 @@
+/****************************************************************************
+ *									    *
+ *									    *
+ *   Unix Randomness-Gathering Code					    *
+ *									    *
+ *   Copyright Peter Gutmann, Paul Kendall, and Chris Wedgwood 1996-1999.   *
+ *   Heavily modified for GnuPG by Werner Koch				    *
+ *									    *
+ *									    *
+ ****************************************************************************/
+
+/* This module is part of the cryptlib continuously seeded pseudorandom
+   number generator.  For usage conditions, see lib_rand.c
+
+   [Here is the notice from lib_rand.c:]
+
+   This module and the misc/rnd*.c modules represent the cryptlib
+   continuously seeded pseudorandom number generator (CSPRNG) as described in
+   my 1998 Usenix Security Symposium paper "The generation of random numbers
+   for cryptographic purposes".
+
+   The CSPRNG code is copyright Peter Gutmann (and various others) 1996,
+   1997, 1998, 1999, all rights reserved.  Redistribution of the CSPRNG
+   modules and use in source and binary forms, with or without modification,
+   are permitted provided that the following conditions are met:
+
+   1. Redistributions of source code must retain the above copyright notice
+      and this permission notice in its entirety.
+
+   2. Redistributions in binary form must reproduce the copyright notice in
+      the documentation and/or other materials provided with the distribution.
+
+   3. A copy of any bugfixes or enhancements made must be provided to the
+      author, <pgut001@cs.auckland.ac.nz> to allow them to be added to the
+      baseline version of the code.
+
+  ALTERNATIVELY, the code may be distributed under the terms of the GNU
+  General Public License, version 2 or any later version published by the
+  Free Software Foundation, in which case the provisions of the GNU GPL are
+  required INSTEAD OF the above restrictions.
+
+  Although not required under the terms of the GPL, it would still be nice if
+  you could make any changes available to the author to allow a consistent
+  code base to be maintained */
+
+
+
+/* General includes */
+
+#include <config.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+
+/* OS-specific includes */
+
+#ifdef __osf__
+  /* Somewhere in the morass of system-specific cruft which OSF/1 pulls in
+   * via the following includes are various endianness defines, so we
+   * undefine the cryptlib ones, which aren't really needed for this module
+   * anyway */
+#undef BIG_ENDIAN
+#undef LITTLE_ENDIAN
+#endif				/* __osf__ */
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <pwd.h>
+#ifndef __QNX__
+#include <sys/errno.h>
+#include <sys/ipc.h>
+#endif				/* __QNX__ */
+#include <sys/time.h>		/* SCO and SunOS need this before resource.h */
+#ifndef __QNX__
+#include <sys/resource.h>
+#endif				/* __QNX__ */
+#if defined( _AIX ) || defined( __QNX__ )
+#include <sys/select.h>
+#endif				/* _AIX || __QNX__ */
+#ifndef __QNX__
+#include <sys/shm.h>
+#include <signal.h>
+#include <sys/signal.h>
+#endif				/* __QNX__ */
+#include <sys/stat.h>
+#include <sys/types.h>		/* Verschiedene komische Typen */
+#if defined( __hpux ) && ( OS_VERSION == 9 )
+#include <vfork.h>
+#endif				/* __hpux 9.x, after that it's in unistd.h */
+#include <sys/wait.h>
+/* #include <kitchensink.h> */
+#ifdef __QNX__
+#include <signal.h>
+#include <process.h>
+#endif		      /* __QNX__ */
+#include <errno.h>
+
+#include "types.h"  /* for byte and u32 typedefs */
+#include "algorithms.h"
+#include "util.h"
+
+#ifndef EAGAIN
+#define EAGAIN	EWOULDBLOCK
+#endif
+#ifndef STDIN_FILENO
+#define STDIN_FILENO 0
+#endif
+#ifndef STDOUT_FILENO
+#define STDOUT_FILENO 1
+#endif
+
+#define GATHER_BUFSIZE		49152	/* Usually about 25K are filled */
+
+/* The structure containing information on random-data sources.  Each
+ * record contains the source and a relative estimate of its usefulness
+ * (weighting) which is used to scale the number of kB of output from the
+ * source (total = data_bytes / usefulness).  Usually the weighting is in the
+ * range 1-3 (or 0 for especially useless sources), resulting in a usefulness
+ * rating of 1...3 for each kB of source output (or 0 for the useless
+ * sources).
+ *
+ * If the source is constantly changing (certain types of network statistics
+ * have this characteristic) but the amount of output is small, the weighting
+ * is given as a negative value to indicate that the output should be treated
+ * as if a minimum of 1K of output had been obtained.  If the source produces
+ * a lot of output then the scale factor is fractional, resulting in a
+ * usefulness rating of < 1 for each kB of source output.
+ *
+ * In order to provide enough randomness to satisfy the requirements for a
+ * slow poll, we need to accumulate at least 20 points of usefulness (a
+ * typical system should get about 30 points).
+ *
+ * Some potential options are missed out because of special considerations.
+ * pstat -i and pstat -f can produce amazing amounts of output (the record
+ * is 600K on an Oracle server) which floods the buffer and doesn't yield
+ * anything useful (apart from perhaps increasing the entropy of the vmstat
+ * output a bit), so we don't bother with this.  pstat in general produces
+ * quite a bit of output, but it doesn't change much over time, so it gets
+ * very low weightings.  netstat -s produces constantly-changing output but
+ * also produces quite a bit of it, so it only gets a weighting of 2 rather
+ * than 3.  The same holds for netstat -in, which gets 1 rather than 2.
+ *
+ * Some binaries are stored in different locations on different systems so
+ * alternative paths are given for them.  The code sorts out which one to
+ * run by itself, once it finds an exectable somewhere it moves on to the
+ * next source.  The sources are arranged roughly in their order of
+ * usefulness, occasionally sources which provide a tiny amount of
+ * relatively useless data are placed ahead of ones which provide a large
+ * amount of possibly useful data because another 100 bytes can't hurt, and
+ * it means the buffer won't be swamped by one or two high-output sources.
+ * All the high-output sources are clustered towards the end of the list
+ * for this reason.  Some binaries are checked for in a certain order, for
+ * example under Slowaris /usr/ucb/ps understands aux as an arg, but the
+ * others don't.  Some systems have conditional defines enabling alternatives
+ * to commands which don't understand the usual options but will provide
+ * enough output (in the form of error messages) to look like they're the
+ * real thing, causing alternative options to be skipped (we can't check the
+ * return either because some commands return peculiar, non-zero status even
+ * when they're working correctly).
+ *
+ * In order to maximise use of the buffer, the code performs a form of run-
+ * length compression on its input where a repeated sequence of bytes is
+ * replaced by the occurrence count mod 256.  Some commands output an awful
+ * lot of whitespace, this measure greatly increases the amount of data we
+ * can fit in the buffer.
+ *
+ * When we scale the weighting using the SC() macro, some preprocessors may
+ * give a division by zero warning for the most obvious expression
+ * 'weight ? 1024 / weight : 0' (and gcc 2.7.2.2 dies with a division by zero
+ * trap), so we define a value SC_0 which evaluates to zero when fed to
+ * '1024 / SC_0' */
+
+#define SC( weight )	( 1024 / weight )	/* Scale factor */
+#define SC_0			16384	/* SC( SC_0 ) evalutes to 0 */
+
+static struct RI {
+    const char *path;		/* Path to check for existence of source */
+    const char *arg;		/* Args for source */
+    const int usefulness;	/* Usefulness of source */
+    FILE *pipe; 		/* Pipe to source as FILE * */
+    int pipeFD; 		/* Pipe to source as FD */
+    pid_t pid;			/* pid of child for waitpid() */
+    int length; 		/* Quantity of output produced */
+    const int hasAlternative;	    /* Whether source has alt.location */
+} dataSources[] = {
+
+    {	"/bin/vmstat", "-s", SC(-3), NULL, 0, 0, 0, 1    },
+    {	"/usr/bin/vmstat", "-s", SC(-3), NULL, 0, 0, 0, 0},
+    {	"/bin/vmstat", "-c", SC(-3), NULL, 0, 0, 0, 1     },
+    {	"/usr/bin/vmstat", "-c", SC(-3), NULL, 0, 0, 0, 0},
+    {	"/usr/bin/pfstat", NULL, SC(-2), NULL, 0, 0, 0, 0},
+    {	"/bin/vmstat", "-i", SC(-2), NULL, 0, 0, 0, 1     },
+    {	"/usr/bin/vmstat", "-i", SC(-2), NULL, 0, 0, 0, 0},
+    {	"/usr/ucb/netstat", "-s", SC(2), NULL, 0, 0, 0, 1 },
+    {	"/usr/bin/netstat", "-s", SC(2), NULL, 0, 0, 0, 1 },
+    {	"/usr/sbin/netstat", "-s", SC(2), NULL, 0, 0, 0, 1},
+    {	"/usr/etc/netstat", "-s", SC(2), NULL, 0, 0, 0, 0},
+    {	"/usr/bin/nfsstat", NULL, SC(2), NULL, 0, 0, 0, 0},
+    {	"/usr/ucb/netstat", "-m", SC(-1), NULL, 0, 0, 0, 1  },
+    {	"/usr/bin/netstat", "-m", SC(-1), NULL, 0, 0, 0, 1  },
+    {	"/usr/sbin/netstat", "-m", SC(-1), NULL, 0, 0, 0, 1 },
+    {	"/usr/etc/netstat", "-m", SC(-1), NULL, 0, 0, 0, 0 },
+    {	"/bin/netstat",     "-in", SC(-1), NULL, 0, 0, 0, 1 },
+    {	"/usr/ucb/netstat", "-in", SC(-1), NULL, 0, 0, 0, 1 },
+    {	"/usr/bin/netstat", "-in", SC(-1), NULL, 0, 0, 0, 1 },
+    {	"/usr/sbin/netstat", "-in", SC(-1), NULL, 0, 0, 0, 1},
+    {	"/usr/etc/netstat", "-in", SC(-1), NULL, 0, 0, 0, 0},
+    {	"/usr/sbin/snmp_request", "localhost public get 1.3.6.1.2.1.7.1.0",
+				    SC(-1), NULL, 0, 0, 0, 0 }, /* UDP in */
+    {	"/usr/sbin/snmp_request", "localhost public get 1.3.6.1.2.1.7.4.0",
+				    SC(-1), NULL, 0, 0, 0, 0 },  /* UDP out */
+    {	"/usr/sbin/snmp_request", "localhost public get 1.3.6.1.2.1.4.3.0",
+				    SC(-1), NULL, 0, 0, 0, 0 }, /* IP ? */
+    {	"/usr/sbin/snmp_request", "localhost public get 1.3.6.1.2.1.6.10.0",
+				    SC(-1), NULL, 0, 0, 0, 0 }, /* TCP ? */
+    {	"/usr/sbin/snmp_request", "localhost public get 1.3.6.1.2.1.6.11.0",
+				    SC(-1), NULL, 0, 0, 0, 0 }, /* TCP ? */
+    {	"/usr/sbin/snmp_request", "localhost public get 1.3.6.1.2.1.6.13.0",
+				    SC(-1), NULL, 0, 0, 0, 0 }, /* TCP ? */
+    {	"/usr/bin/mpstat", NULL, SC(1), NULL, 0, 0, 0, 0     },
+    {	"/usr/bin/w", NULL, SC(1), NULL, 0, 0, 0, 1           },
+    {	"/usr/bsd/w", NULL, SC(1), NULL, 0, 0, 0, 0          },
+    {	"/usr/bin/df", NULL, SC(1), NULL, 0, 0, 0, 1          },
+    {	"/bin/df", NULL, SC(1), NULL, 0, 0, 0, 0             },
+    {	"/usr/sbin/portstat", NULL, SC(1), NULL, 0, 0, 0, 0  },
+    {	"/usr/bin/iostat", NULL, SC(SC_0), NULL, 0, 0, 0, 0  },
+    {	"/usr/bin/uptime", NULL, SC(SC_0), NULL, 0, 0, 0, 1   },
+    {	"/usr/bsd/uptime", NULL, SC(SC_0), NULL, 0, 0, 0, 0  },
+    {	"/bin/vmstat", "-f", SC(SC_0), NULL, 0, 0, 0, 1       },
+    {	"/usr/bin/vmstat", "-f", SC(SC_0), NULL, 0, 0, 0, 0  },
+    {	"/bin/vmstat", NULL, SC(SC_0), NULL, 0, 0, 0, 1       },
+    {	"/usr/bin/vmstat", NULL, SC(SC_0), NULL, 0, 0, 0, 0  },
+    {	"/usr/ucb/netstat", "-n", SC(0.5), NULL, 0, 0, 0, 1   },
+    {	"/usr/bin/netstat", "-n", SC(0.5), NULL, 0, 0, 0, 1   },
+    {	"/usr/sbin/netstat", "-n", SC(0.5), NULL, 0, 0, 0, 1  },
+    {	"/usr/etc/netstat", "-n", SC(0.5), NULL, 0, 0, 0, 0  },
+#if defined( __sgi ) || defined( __hpux )
+    {	"/bin/ps", "-el", SC(0.3), NULL, 0, 0, 0, 1           },
+#endif				/* __sgi || __hpux */
+    {	"/usr/ucb/ps", "aux", SC(0.3), NULL, 0, 0, 0, 1       },
+    {	"/usr/bin/ps", "aux", SC(0.3), NULL, 0, 0, 0, 1       },
+    {	"/bin/ps", "aux", SC(0.3), NULL, 0, 0, 0, 0          },
+    {   "/bin/ps", "-A", SC(0.3), NULL, 0, 0, 0, 0           }, /*QNX*/
+    {	"/usr/bin/ipcs", "-a", SC(0.5), NULL, 0, 0, 0, 1      },
+    {	"/bin/ipcs", "-a", SC(0.5), NULL, 0, 0, 0, 0         },
+    /* Unreliable source, depends on system usage */
+    {	"/etc/pstat", "-p", SC(0.5), NULL, 0, 0, 0, 1         },
+    {	"/bin/pstat", "-p", SC(0.5), NULL, 0, 0, 0, 0        },
+    {	"/etc/pstat", "-S", SC(0.2), NULL, 0, 0, 0, 1         },
+    {	"/bin/pstat", "-S", SC(0.2), NULL, 0, 0, 0, 0        },
+    {	"/etc/pstat", "-v", SC(0.2), NULL, 0, 0, 0, 1         },
+    {	"/bin/pstat", "-v", SC(0.2), NULL, 0, 0, 0, 0        },
+    {	"/etc/pstat", "-x", SC(0.2), NULL, 0, 0, 0, 1         },
+    {	"/bin/pstat", "-x", SC(0.2), NULL, 0, 0, 0, 0        },
+    {	"/etc/pstat", "-t", SC(0.1), NULL, 0, 0, 0, 1         },
+    {	"/bin/pstat", "-t", SC(0.1), NULL, 0, 0, 0, 0        },
+    /* pstat is your friend */
+    {	"/usr/bin/last", "-n 50", SC(0.3), NULL, 0, 0, 0, 1   },
+#ifdef __sgi
+    {	"/usr/bsd/last", "-50", SC(0.3), NULL, 0, 0, 0, 0    },
+#endif				/* __sgi */
+#ifdef __hpux
+    {	"/etc/last", "-50", SC(0.3), NULL, 0, 0, 0, 0        },
+#endif				/* __hpux */
+    {	"/usr/bsd/last", "-n 50", SC(0.3), NULL, 0, 0, 0, 0  },
+    {	"/usr/sbin/snmp_request", "localhost public get 1.3.6.1.2.1.5.1.0",
+				SC(0.1), NULL, 0, 0, 0, 0 }, /* ICMP ? */
+    {	"/usr/sbin/snmp_request", "localhost public get 1.3.6.1.2.1.5.3.0",
+				SC(0.1), NULL, 0, 0, 0, 0 }, /* ICMP ? */
+    {	"/etc/arp", "-a", SC(0.1), NULL, 0, 0, 0, 1  },
+    {	"/usr/etc/arp", "-a", SC(0.1), NULL, 0, 0, 0, 1  },
+    {	"/usr/bin/arp", "-a", SC(0.1), NULL, 0, 0, 0, 1  },
+    {	"/usr/sbin/arp", "-a", SC(0.1), NULL, 0, 0, 0, 0 },
+    {	"/usr/sbin/ripquery", "-nw 1 127.0.0.1",
+				SC(0.1), NULL, 0, 0, 0, 0 },
+    {	"/bin/lpstat", "-t", SC(0.1), NULL, 0, 0, 0, 1     },
+    {	"/usr/bin/lpstat", "-t", SC(0.1), NULL, 0, 0, 0, 1 },
+    {	"/usr/ucb/lpstat", "-t", SC(0.1), NULL, 0, 0, 0, 0 },
+    {	"/usr/bin/tcpdump", "-c 5 -efvvx", SC(1), NULL, 0, 0, 0, 0 },
+    /* This is very environment-dependant.  If network traffic is low, it'll
+     * probably time out before delivering 5 packets, which is OK because
+     * it'll probably be fixed stuff like ARP anyway */
+    {	"/usr/sbin/advfsstat", "-b usr_domain",
+				SC(SC_0), NULL, 0, 0, 0, 0},
+    {	"/usr/sbin/advfsstat", "-l 2 usr_domain",
+				SC(0.5), NULL, 0, 0, 0, 0},
+    {	"/usr/sbin/advfsstat", "-p usr_domain",
+				SC(SC_0), NULL, 0, 0, 0, 0},
+    /* This is a complex and screwball program.  Some systems have things
+     * like rX_dmn, x = integer, for RAID systems, but the statistics are
+     * pretty dodgy */
+#ifdef __QNXNTO__                                                             
+    { "/bin/pidin", "-F%A%B%c%d%E%I%J%K%m%M%n%N%p%P%S%s%T", SC(0.3),
+             NULL, 0, 0, 0, 0       },
+#endif     
+#if 0
+    /* The following aren't enabled since they're somewhat slow and not very
+     * unpredictable, however they give an indication of the sort of sources
+     * you can use (for example the finger might be more useful on a
+     * firewalled internal network) */
+    {	"/usr/bin/finger", "@ml.media.mit.edu", SC(0.9), NULL, 0, 0, 0, 0 },
+    {	"/usr/local/bin/wget", "-O - http://lavarand.sgi.com/block.html",
+				SC(0.9), NULL, 0, 0, 0, 0 },
+    {	"/bin/cat", "/usr/spool/mqueue/syslog", SC(0.9), NULL, 0, 0, 0, 0 },
+#endif				/* 0 */
+    {	NULL, NULL, 0, NULL, 0, 0, 0, 0 }
+};
+
+static byte *gather_buffer;	    /* buffer for gathering random noise */
+static int gather_buffer_size;	    /* size of the memory buffer */
+static uid_t gatherer_uid;
+
+/* The message structure used to communicate with the parent */
+typedef struct {
+    int  usefulness;	/* usefulness of data */
+    int  ndata; 	/* valid bytes in data */
+    char data[500];	/* gathered data */
+} GATHER_MSG;
+
+
+#ifndef HAVE_WAITPID
+pid_t
+waitpid(pid_t pid, int *statptr, int options)
+{
+#ifdef HAVE_WAIT4
+	return wait4(pid, statptr, options, NULL);
+#else
+	/* If wait4 is also not available, try wait3 for SVR3 variants */
+	/* Less ideal because can't actually request a specific pid */
+	/* For that reason, first check to see if pid is for an */
+	/*   existing process. */
+	int tmp_pid, dummystat;;
+	if (kill(pid, 0) == -1) {
+		errno = ECHILD;
+		return -1;
+	}
+	if (statptr == NULL)
+		statptr = &dummystat;
+	while (((tmp_pid = wait3(statptr, options, 0)) != pid) &&
+		    (tmp_pid != -1) && (tmp_pid != 0) && (pid != -1))
+	    ;
+	return tmp_pid;
+#endif
+}
+#endif
+
+
+/* Under SunOS popen() doesn't record the pid of the child process.  When
+ * pclose() is called, instead of calling waitpid() for the correct child, it
+ * calls wait() repeatedly until the right child is reaped.  The problem is
+ * that this reaps any other children that happen to have died at that
+ * moment, and when their pclose() comes along, the process hangs forever.
+ * The fix is to use a wrapper for popen()/pclose() which saves the pid in
+ * the dataSources structure (code adapted from GNU-libc's popen() call).
+ *
+ * Aut viam inveniam aut faciam */
+
+static FILE *
+my_popen(struct RI *entry)
+{
+
+    int pipedes[2];
+    FILE *stream;
+
+    /* Create the pipe */
+    if (pipe(pipedes) < 0)
+	return (NULL);
+
+    /* Fork off the child ("vfork() is like an OS orgasm.  All OS's want to
+     * do it, but most just end up faking it" - Chris Wedgwood).  If your OS
+     * supports it, you should try to use vfork() here because it's somewhat
+     * more efficient */
+#if defined( sun ) || defined( __ultrix__ ) || defined( __osf__ ) || \
+	defined(__hpux)
+    entry->pid = vfork();
+#else				/*  */
+    entry->pid = fork();
+#endif				/* Unixen which have vfork() */
+    if (entry->pid == (pid_t) - 1) {
+	/* The fork failed */
+	close(pipedes[0]);
+	close(pipedes[1]);
+	return (NULL);
+    }
+
+    if (entry->pid == (pid_t) 0) {
+	struct passwd *passwd;
+	int fd;
+
+	/* We are the child.  Make the read side of the pipe be stdout */
+	if (dup2(pipedes[STDOUT_FILENO], STDOUT_FILENO) < 0)
+	    exit(127);
+	/* Connect the other standard handles to the bit bucket. */
+	if ((fd = open ("/dev/null", O_RDWR)) != -1) {
+           dup2 (fd, STDIN_FILENO);
+           dup2 (fd, STDERR_FILENO);
+           close (fd);
+	}
+
+	/* Now that everything is set up, give up our permissions to make
+	 * sure we don't read anything sensitive.  If the getpwnam() fails,
+	 * we default to -1, which is usually nobody */
+	if (gatherer_uid == (uid_t)-1 && \
+	    (passwd = getpwnam("nobody")) != NULL)
+	    gatherer_uid = passwd->pw_uid;
+
+	setuid(gatherer_uid);
+
+	/* Close the pipe descriptors. */
+	close(pipedes[STDIN_FILENO]);
+	close(pipedes[STDOUT_FILENO]);
+
+	/* Try and exec the program */
+	execl(entry->path, entry->path, entry->arg, NULL);
+
+	/* Die if the exec failed */
+	exit(127);
+    }
+
+    /* We are the parent.  Close the irrelevant side of the pipe and open
+     * the relevant side as a new stream.  Mark our side of the pipe to
+     * close on exec, so new children won't see it */
+    close(pipedes[STDOUT_FILENO]);
+
+#ifdef FD_CLOEXEC
+    fcntl(pipedes[STDIN_FILENO], F_SETFD, FD_CLOEXEC);
+#endif
+
+    stream = fdopen(pipedes[STDIN_FILENO], "r");
+
+    if (stream == NULL) {
+	int savedErrno = errno;
+
+	/* The stream couldn't be opened or the child structure couldn't be
+	 * allocated.  Kill the child and close the other side of the pipe */
+	kill(entry->pid, SIGKILL);
+	if (stream == NULL)
+	    close(pipedes[STDOUT_FILENO]);
+	else
+	    fclose(stream);
+
+	waitpid(entry->pid, NULL, 0);
+
+	entry->pid = 0;
+	errno = savedErrno;
+	return (NULL);
+    }
+
+    return (stream);
+}
+
+static int
+my_pclose(struct RI *entry)
+{
+    int status = 0;
+
+    if (fclose(entry->pipe))
+	return (-1);
+
+    /* We ignore the return value from the process because some programs
+     * return funny values which would result in the input being discarded
+     * even if they executed successfully.  This isn't a problem because the
+     * result data size threshold will filter out any programs which exit
+     * with a usage message without producing useful output */
+    if (waitpid(entry->pid, NULL, 0) != entry->pid)
+	status = -1;
+
+    entry->pipe = NULL;
+    entry->pid = 0;
+    return (status);
+}
+
+
+/* Unix slow poll (without special support for Linux)
+ *
+ * If a few of the randomness sources create a large amount of output then
+ * the slowPoll() stops once the buffer has been filled (but before all the
+ * randomness sources have been sucked dry) so that the 'usefulness' factor
+ * remains below the threshold.  For this reason the gatherer buffer has to
+ * be fairly sizeable on moderately loaded systems.  This is something of a
+ * bug since the usefulness should be influenced by the amount of output as
+ * well as the source type */
+
+
+static int
+slow_poll(FILE *dbgfp, int dbgall, size_t *nbytes )
+{
+    int moreSources;
+    struct timeval tv;
+    fd_set fds;
+#if defined( __hpux )
+    size_t maxFD = 0;
+#else
+    int maxFD = 0;
+#endif /* OS-specific brokenness */
+    int bufPos, i, usefulness = 0;
+
+
+    /* Fire up each randomness source */
+    FD_ZERO(&fds);
+    for (i = 0; dataSources[i].path != NULL; i++) {
+	/* Since popen() is a fairly heavy function, we check to see whether
+	 * the executable exists before we try to run it */
+	if (access(dataSources[i].path, X_OK)) {
+	    if( dbgfp && dbgall )
+		fprintf(dbgfp, "%s not present%s\n", dataSources[i].path,
+			       dataSources[i].hasAlternative ?
+					", has alternatives" : "");
+	    dataSources[i].pipe = NULL;
+	}
+	else
+	    dataSources[i].pipe = my_popen(&dataSources[i]);
+
+	if (dataSources[i].pipe != NULL) {
+	    dataSources[i].pipeFD = fileno(dataSources[i].pipe);
+	    if (dataSources[i].pipeFD > maxFD)
+		maxFD = dataSources[i].pipeFD;
+#ifdef O_NONBLOCK /* Ohhh what a hack (used for Atari) */
+	    fcntl(dataSources[i].pipeFD, F_SETFL, O_NONBLOCK);
+#endif
+	    FD_SET(dataSources[i].pipeFD, &fds);
+	    dataSources[i].length = 0;
+
+	    /* If there are alternatives for this command, don't try and
+	     * execute them */
+	    while (dataSources[i].hasAlternative) {
+		if( dbgfp && dbgall )
+		    fprintf(dbgfp, "Skipping %s\n", dataSources[i + 1].path);
+		i++;
+	    }
+	}
+    }
+
+
+    /* Suck all the data we can get from each of the sources */
+    bufPos = 0;
+    moreSources = 1;
+    while (moreSources && bufPos <= gather_buffer_size) {
+	/* Wait for data to become available from any of the sources, with a
+	 * timeout of 10 seconds.  This adds even more randomness since data
+	 * becomes available in a nondeterministic fashion.  Kudos to HP's QA
+	 * department for managing to ship a select() which breaks its own
+	 * prototype */
+	tv.tv_sec = 10;
+	tv.tv_usec = 0;
+
+#if defined( __hpux ) && ( OS_VERSION == 9 )
+	if (select(maxFD + 1, (int *)&fds, NULL, NULL, &tv) == -1)
+#else  /*  */
+	if (select(maxFD + 1, &fds, NULL, NULL, &tv) == -1)
+#endif /* __hpux */
+	    break;
+
+	/* One of the sources has data available, read it into the buffer */
+	for (i = 0; dataSources[i].path != NULL; i++) {
+	    if( dataSources[i].pipe && FD_ISSET(dataSources[i].pipeFD, &fds)) {
+		size_t noBytes;
+
+		if ((noBytes = fread(gather_buffer + bufPos, 1,
+				     gather_buffer_size - bufPos,
+				     dataSources[i].pipe)) == 0) {
+		    if (my_pclose(&dataSources[i]) == 0) {
+			int total = 0;
+
+			/* Try and estimate how much entropy we're getting
+			 * from a data source */
+			if (dataSources[i].usefulness) {
+			    if (dataSources[i].usefulness < 0)
+				total = (dataSources[i].length + 999)
+					/ -dataSources[i].usefulness;
+			    else
+				total = dataSources[i].length
+					/ dataSources[i].usefulness;
+			}
+			if( dbgfp )
+			    fprintf(dbgfp,
+			       "%s %s contributed %d bytes, "
+			       "usefulness = %d\n", dataSources[i].path,
+			       (dataSources[i].arg != NULL) ?
+				       dataSources[i].arg : "",
+				      dataSources[i].length, total);
+			if( dataSources[i].length )
+			    usefulness += total;
+		    }
+		    dataSources[i].pipe = NULL;
+		}
+		else {
+		    int currPos = bufPos;
+		    int endPos = bufPos + noBytes;
+
+		    /* Run-length compress the input byte sequence */
+		    while (currPos < endPos) {
+			int ch = gather_buffer[currPos];
+
+			/* If it's a single byte, just copy it over */
+			if (ch != gather_buffer[currPos + 1]) {
+			    gather_buffer[bufPos++] = ch;
+			    currPos++;
+			}
+			else {
+			    int count = 0;
+
+			    /* It's a run of repeated bytes, replace them
+			     * with the byte count mod 256 */
+			    while ((ch == gather_buffer[currPos])
+				    && currPos < endPos) {
+				count++;
+				currPos++;
+			    }
+			    gather_buffer[bufPos++] = count;
+			    noBytes -= count - 1;
+			}
+		    }
+
+		    /* Remember the number of (compressed) bytes of input we
+		     * obtained */
+		    dataSources[i].length += noBytes;
+		}
+	    }
+	}
+
+	/* Check if there is more input available on any of the sources */
+	moreSources = 0;
+	FD_ZERO(&fds);
+	for (i = 0; dataSources[i].path != NULL; i++) {
+	    if (dataSources[i].pipe != NULL) {
+		FD_SET(dataSources[i].pipeFD, &fds);
+		moreSources = 1;
+	    }
+	}
+    }
+
+    if( dbgfp ) {
+	fprintf(dbgfp, "Got %d bytes, usefulness = %d\n", bufPos, usefulness);
+	fflush(dbgfp);
+    }
+    *nbytes = bufPos;
+    return usefulness;
+}
+
+/****************
+ * Start the gatherer process which writes messages of
+ * type GATHERER_MSG to pipedes
+ */
+static void
+start_gatherer( int pipefd )
+{
+    FILE *dbgfp = NULL;
+    int dbgall;
+
+#ifdef ENABLE_SELINUX_HACKS
+    /* We don't allow writing to the log file because this might be
+       sued to corrupt a secured file.  Given that this is used as a
+       library by the ../g10/ code, we can't access the check function
+       from ../g10/misc.c.  */
+    dbgall = 0;
+#else
+    {
+	const char *s = getenv("GNUPG_RNDUNIX_DBG");
+	if( s ) {
+	    dbgfp = (*s=='-' && !s[1])? stdout : fopen(s, "a");
+	    if( !dbgfp )
+		g10_log_info("can't open debug file `%s': %s\n",
+			     s, strerror(errno) );
+	    else
+		fprintf(dbgfp,"\nSTART RNDUNIX DEBUG pid=%d\n", (int)getpid());
+	}
+	dbgall = !!getenv("GNUPG_RNDUNIX_DBGALL");
+    }
+#endif
+
+    /* Set up the buffer */
+    gather_buffer_size = GATHER_BUFSIZE;
+    gather_buffer = malloc( gather_buffer_size );
+    if( !gather_buffer ) {
+	g10_log_error("out of core while allocating the gatherer buffer\n");
+	exit(2);
+    }
+
+    /* Reset the SIGC(H)LD handler to the system default.  This is necessary
+     * because if the program which cryptlib is a part of installs its own
+     * SIGC(H)LD handler, it will end up reaping the cryptlib children before
+     * cryptlib can.  As a result, my_pclose() will call waitpid() on a
+     * process which has already been reaped by the installed handler and
+     * return an error, so the read data won't be added to the randomness
+     * pool.  There are two types of SIGC(H)LD naming, the SysV SIGCLD and
+     * the BSD/Posix SIGCHLD, so we need to handle either possibility */
+#ifdef SIGCLD
+    signal(SIGCLD, SIG_DFL);
+#else
+    signal(SIGCHLD, SIG_DFL);
+#endif
+
+    fflush (stderr);
+    /* Arrghh!!  It's Stuart code!! */
+    /* (close all files but the ones we need) */
+    {	int nmax, n1, i;
+#ifdef _SC_OPEN_MAX
+	if( (nmax=sysconf( _SC_OPEN_MAX )) < 0 ) {
+#ifdef _POSIX_OPEN_MAX
+	    nmax = _POSIX_OPEN_MAX;
+#else
+	    nmax = 20; /* assume a reasonable value */
+#endif
+	}
+#else
+	nmax = 20; /* assume a reasonable value */
+#endif
+	{  
+	  int fd;
+	  if ((fd = open ("/dev/null", O_RDWR)) != -1) {
+	    dup2 (fd, STDIN_FILENO);
+	    dup2 (fd, STDOUT_FILENO);
+	    dup2 (fd, STDERR_FILENO);
+	    close (fd);
+	  }
+	}
+	n1 = dbgfp? fileno (dbgfp) : -1;
+	for(i=0; i < nmax; i++ ) {
+	    if (i != STDIN_FILENO && i != STDOUT_FILENO && i != STDERR_FILENO
+		&& i != n1 && i != pipefd )
+	      close(i);
+	}
+	errno = 0;
+    }
+
+
+    for(;;) {
+	GATHER_MSG msg;
+	size_t nbytes;
+	const char *p;
+
+	msg.usefulness = slow_poll( dbgfp, dbgall, &nbytes );
+	p = gather_buffer;
+	while( nbytes ) {
+	    msg.ndata = nbytes > sizeof(msg.data)? sizeof(msg.data) : nbytes;
+	    memcpy( msg.data, p, msg.ndata );
+	    nbytes -= msg.ndata;
+	    p += msg.ndata;
+
+	    while( write( pipefd, &msg, sizeof(msg) ) != sizeof(msg) ) {
+		if( errno == EINTR )
+		    continue;
+		if( errno == EAGAIN ) {
+		    struct timeval tv;
+		    tv.tv_sec = 0;
+		    tv.tv_usec = 50000;
+		    select(0, NULL, NULL, NULL, &tv);
+		    continue;
+		}
+		if( errno == EPIPE ) /* parent has exited, so give up */
+		   exit(0);
+
+		/* we can't do very much here because stderr is closed */
+		if( dbgfp )
+		    fprintf(dbgfp, "gatherer can't write to pipe: %s\n",
+				    strerror(errno) );
+		/* we start a new poll to give the system some time */
+		nbytes = 0;
+		break;
+	    }
+	}
+    }
+    /* we are killed when the parent dies */
+}
+
+
+static int
+read_a_msg( int fd, GATHER_MSG *msg )
+{
+    char *buffer = (char*)msg;
+    size_t length = sizeof( *msg );
+    int n;
+
+    do {
+	do {
+	    n = read(fd, buffer, length );
+	} while( n == -1 && errno == EINTR );
+	if( n == -1 )
+	    return -1;
+	buffer += n;
+	length -= n;
+    } while( length );
+    return 0;
+}
+
+
+/****************
+ * Using a level of 0 should never block and better add nothing
+ * to the pool.  So this is just a dummy for this gatherer.
+ */
+int
+rndunix_gather_random( void (*add)(const void*, size_t, int), int requester,
+                       size_t length, int level )
+{
+    static pid_t gatherer_pid = 0;
+    static int pipedes[2];
+    GATHER_MSG msg;
+    size_t n;
+
+    if( !level )
+	return 0;
+
+    if( !gatherer_pid ) {
+	/* make sure we are not setuid */
+	if( getuid() != geteuid() )
+	    BUG();
+	/* time to start the gatherer process */
+	if( pipe( pipedes ) ) {
+	    g10_log_error("pipe() failed: %s\n", strerror(errno));
+	    return -1;
+	}
+	gatherer_pid = fork();
+	if( gatherer_pid == -1 ) {
+	    g10_log_error("can't for gatherer process: %s\n", strerror(errno));
+	    return -1;
+	}
+	if( !gatherer_pid ) {
+	    start_gatherer( pipedes[1] );
+	    /* oops, can't happen */
+	    return -1;
+	}
+    }
+
+    /* now read from the gatherer */
+    while( length ) {
+	int goodness;
+	ulong subtract;
+
+	if( read_a_msg( pipedes[0], &msg ) ) {
+	    g10_log_error("reading from gatherer pipe failed: %s\n",
+							    strerror(errno));
+	    return -1;
+	}
+
+
+	if( level > 1 ) {
+	    if( msg.usefulness > 30 )
+		goodness = 100;
+	    else if ( msg.usefulness )
+		goodness = msg.usefulness * 100 / 30;
+	    else
+		goodness = 0;
+	}
+	else if( level ) {
+	    if( msg.usefulness > 15 )
+		goodness = 100;
+	    else if ( msg.usefulness )
+		goodness = msg.usefulness * 100 / 15;
+	    else
+		goodness = 0;
+	}
+	else
+	    goodness = 100; /* goodness of level 0 is always 100 % */
+
+	n = msg.ndata;
+	if( n > length )
+	    n = length;
+	(*add)( msg.data, n, requester );
+
+	/* this is the trick how e cope with the goodness */
+	subtract = (ulong)n * goodness / 100;
+	/* subtract at least 1 byte to avoid infinite loops */
+	length -= subtract ? subtract : 1;
+    }
+
+    return 0;
+}