Initial revision

1 files changed, 653 insertions, 0 deletions

diff --git a/pwmanager/libcrypt/crypt/secmem.c b/pwmanager/libcrypt/crypt/secmem.c
new file mode 100644
index 0000000..163bf20
--- a/dev/null
+++ b/pwmanager/libcrypt/crypt/secmem.c
@@ -0,0 +1,653 @@
+/* secmem.c  -	memory allocation from a secure heap
+ * Copyright (C) 1998, 1999, 2000, 2001, 2002,
+ *               2003 Free Software Foundation, Inc.
+ *
+ * This file is part of Libgcrypt.
+ *
+ * Libgcrypt is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser general Public License as
+ * published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * Libgcrypt 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser 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 <string.h>
+#include <errno.h>
+#include <stdarg.h>
+#include <unistd.h>
+#include <stddef.h>
+
+#if defined(HAVE_MLOCK) || defined(HAVE_MMAP)
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#ifdef USE_CAPABILITIES
+#include <sys/capability.h>
+#endif
+#endif
+
+#include "ath.h"
+#include "g10lib.h"
+#include "secmem.h"
+
+#if defined (MAP_ANON) && ! defined (MAP_ANONYMOUS)
+#define MAP_ANONYMOUS MAP_ANON
+#endif
+
+#define DEFAULT_POOL_SIZE 16384
+#define DEFAULT_PAGE_SIZE 4096
+
+typedef struct memblock
+{
+  unsigned size;		/* Size of the memory available to the
+				   user.  */
+  int flags;			/* See below.  */
+  PROPERLY_ALIGNED_TYPE aligned;
+} memblock_t;
+
+/* This flag specifies that the memory block is in use.  */
+#define MB_FLAG_ACTIVE 1 << 0
+
+/* The pool of secure memory.  */
+static void *pool;
+
+/* Size of POOL in bytes.  */
+static size_t pool_size;
+
+/* True, if the memory pool is ready for use.  May be checked in an
+   atexit function.  */
+static volatile int pool_okay;
+
+/* True, if the memory pool is mmapped.  */
+static volatile int pool_is_mmapped;
+
+/* FIXME?  */
+static int disable_secmem;
+static int show_warning;
+static int no_warning;
+static int suspend_warning;
+
+/* Stats.  */
+static unsigned int cur_alloced, cur_blocks;
+
+/* Lock protecting accesses to the memory pool.  */
+static ath_mutex_t secmem_lock;
+
+/* Convenient macros.  */
+#define SECMEM_LOCK   ath_mutex_lock   (&secmem_lock)
+#define SECMEM_UNLOCK ath_mutex_unlock (&secmem_lock)
+
+/* The size of the memblock structure; this does not include the
+   memory that is available to the user.  */
+#define BLOCK_HEAD_SIZE \
+  offsetof (memblock_t, aligned)
+
+/* Convert an address into the according memory block structure.  */
+#define ADDR_TO_BLOCK(addr) \
+  (memblock_t *) ((char *) addr - BLOCK_HEAD_SIZE)
+
+/* Check wether MB is a valid block.  */
+#define BLOCK_VALID(mb) \
+  (((char *) mb - (char *) pool) < pool_size)
+
+/* Update the stats.  */
+static void
+stats_update (size_t add, size_t sub)
+{
+  if (add)
+    {
+      cur_alloced += add;
+      cur_blocks++;
+    }
+  if (sub)
+    {
+      cur_alloced -= sub;
+      cur_blocks--;
+    }
+}
+
+/* Return the block following MB or NULL, if MB is the last block.  */
+static memblock_t *
+mb_get_next (memblock_t *mb)
+{
+  memblock_t *mb_next;
+
+  mb_next = (memblock_t *) ((char *) mb + BLOCK_HEAD_SIZE + mb->size);
+  
+  if (! BLOCK_VALID (mb_next))
+    mb_next = NULL;
+
+  return mb_next;
+}
+
+/* Return the block preceeding MB or NULL, if MB is the first
+   block.  */
+static memblock_t *
+mb_get_prev (memblock_t *mb)
+{
+  memblock_t *mb_prev, *mb_next;
+
+  if (mb == pool)
+    mb_prev = NULL;
+  else
+    {
+      mb_prev = (memblock_t *) pool;
+      while (1)
+	{
+	  mb_next = mb_get_next (mb_prev);
+	  if (mb_next == mb)
+	    break;
+	  else
+	    mb_prev = mb_next;
+	}
+    }
+
+  return mb_prev;
+}
+
+/* If the preceeding block of MB and/or the following block of MB
+   exist and are not active, merge them to form a bigger block.  */
+static void
+mb_merge (memblock_t *mb)
+{
+  memblock_t *mb_prev, *mb_next;
+
+  mb_prev = mb_get_prev (mb);
+  mb_next = mb_get_next (mb);
+
+  if (mb_prev && (! (mb_prev->flags & MB_FLAG_ACTIVE)))
+    {
+      mb_prev->size += BLOCK_HEAD_SIZE + mb->size;
+      mb = mb_prev;
+    }
+  if (mb_next && (! (mb_next->flags & MB_FLAG_ACTIVE)))
+    mb->size += BLOCK_HEAD_SIZE + mb_next->size;
+}
+
+/* Return a new block, which can hold SIZE bytes.  */
+static memblock_t *
+mb_get_new (memblock_t *block, size_t size)
+{
+  memblock_t *mb, *mb_split;
+  
+  for (mb = block; BLOCK_VALID (mb); mb = mb_get_next (mb))
+    if (! (mb->flags & MB_FLAG_ACTIVE) && mb->size >= size)
+      {
+	/* Found a free block.  */
+	mb->flags |= MB_FLAG_ACTIVE;
+
+	if (mb->size - size > BLOCK_HEAD_SIZE)
+	  {
+	    /* Split block.  */
+	  
+	    mb_split = (memblock_t *) (((char *) mb) + BLOCK_HEAD_SIZE + size);
+	    mb_split->size = mb->size - size - BLOCK_HEAD_SIZE;
+	    mb_split->flags = 0;
+
+	    mb->size = size;
+
+	    mb_merge (mb_split);
+
+	  }
+
+	break;
+      }
+
+  if (! BLOCK_VALID (mb))
+    mb = NULL;
+
+  return mb;
+}
+
+/* Print a warning message.  */
+static void
+print_warn (void)
+{
+  if (!no_warning)
+    log_info (_("Warning: using insecure memory!\n"));
+}
+
+/* Lock the memory pages into core and drop privileges.  */
+static void
+lock_pool (void *p, size_t n)
+{
+#if defined(USE_CAPABILITIES) && defined(HAVE_MLOCK)
+  int err;
+
+  cap_set_proc (cap_from_text ("cap_ipc_lock+ep"));
+  err = mlock (p, n);
+  if (err && errno)
+    err = errno;
+  cap_set_proc (cap_from_text ("cap_ipc_lock+p"));
+
+  if (err)
+    {
+      if (errno != EPERM
+#ifdef EAGAIN	/* OpenBSD returns this */
+	  && errno != EAGAIN
+#endif
+#ifdef ENOSYS	/* Some SCOs return this (function not implemented) */
+	  && errno != ENOSYS
+#endif
+#ifdef ENOMEM  /* Linux might return this. */
+            && errno != ENOMEM
+#endif
+	  )
+	log_error ("can't lock memory: %s\n", strerror (err));
+      show_warning = 1;
+    }
+
+#elif defined(HAVE_MLOCK)
+  uid_t uid;
+  int err;
+
+  uid = getuid ();
+
+#ifdef HAVE_BROKEN_MLOCK
+  /* Under HP/UX mlock segfaults if called by non-root.  Note, we have
+     noch checked whether mlock does really work under AIX where we
+     also detected a broken nlock.  Note further, that using plock ()
+     is not a good idea under AIX. */ 
+  if (uid)
+    {
+      errno = EPERM;
+      err = errno;
+    }
+  else
+    {
+      err = mlock (p, n);
+      if (err && errno)
+	err = errno;
+    }
+#else /* !HAVE_BROKEN_MLOCK */
+  err = mlock (p, n);
+  if (err && errno)
+    err = errno;
+#endif /* !HAVE_BROKEN_MLOCK */
+
+  if (uid && ! geteuid ())
+    {
+      /* check that we really dropped the privs.
+       * Note: setuid(0) should always fail */
+      if (setuid (uid) || getuid () != geteuid () || !setuid (0))
+	log_fatal ("failed to reset uid: %s\n", strerror (errno));
+    }
+
+  if (err)
+    {
+      if (errno != EPERM
+#ifdef EAGAIN	/* OpenBSD returns this. */
+	  && errno != EAGAIN
+#endif
+#ifdef ENOSYS	/* Some SCOs return this (function not implemented). */
+	  && errno != ENOSYS
+#endif
+#ifdef ENOMEM  /* Linux might return this. */
+            && errno != ENOMEM
+#endif
+	  )
+	log_error ("can't lock memory: %s\n", strerror (err));
+      show_warning = 1;
+    }
+
+#elif defined ( __QNX__ )
+  /* QNX does not page at all, so the whole secure memory stuff does
+   * not make much sense.  However it is still of use because it
+   * wipes out the memory on a free().
+   * Therefore it is sufficient to suppress the warning
+   */
+#elif defined (HAVE_DOSISH_SYSTEM) || defined (__CYGWIN__)
+    /* It does not make sense to print such a warning, given the fact that 
+     * this whole Windows !@#$% and their user base are inherently insecure
+     */
+#elif defined (__riscos__)
+    /* no virtual memory on RISC OS, so no pages are swapped to disc,
+     * besides we don't have mmap, so we don't use it! ;-)
+     * But don't complain, as explained above.
+     */
+#else
+  log_info ("Please note that you don't have secure memory on this system\n");
+#endif
+}
+
+/* Initialize POOL.  */
+static void
+init_pool (size_t n)
+{
+  size_t pgsize;
+  memblock_t *mb;
+
+  pool_size = n;
+
+  if (disable_secmem)
+    log_bug ("secure memory is disabled");
+
+#ifdef HAVE_GETPAGESIZE
+  pgsize = getpagesize ();
+#else
+  pgsize = DEFAULT_PAGE_SIZE;
+#endif
+
+#if HAVE_MMAP
+  pool_size = (pool_size + pgsize - 1) & ~(pgsize - 1);
+#ifdef MAP_ANONYMOUS
+  pool = mmap (0, pool_size, PROT_READ | PROT_WRITE,
+	       MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+#else /* map /dev/zero instead */
+  {
+    int fd;
+
+    fd = open ("/dev/zero", O_RDWR);
+    if (fd == -1)
+      {
+	log_error ("can't open /dev/zero: %s\n", strerror (errno));
+	pool = (void *) -1;
+      }
+    else
+      {
+	pool = mmap (0, pool_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
+      }
+  }
+#endif
+  if (pool == (void *) -1)
+    log_info ("can't mmap pool of %u bytes: %s - using malloc\n",
+	      (unsigned) pool_size, strerror (errno));
+  else
+    {
+      pool_is_mmapped = 1;
+      pool_okay = 1;
+    }
+
+#endif
+  if (!pool_okay)
+    {
+      pool = malloc (pool_size);
+      if (!pool)
+	log_fatal ("can't allocate memory pool of %u bytes\n",
+		   (unsigned) pool_size);
+      else
+	pool_okay = 1;
+    }
+
+  /* Initialize first memory block.  */
+  mb = (memblock_t *) pool;
+  mb->size = pool_size;
+  mb->flags = 0;
+}
+
+void
+_gcry_secmem_set_flags (unsigned flags)
+{
+  int was_susp;
+
+  SECMEM_LOCK;
+
+  was_susp = suspend_warning;
+  no_warning = flags & GCRY_SECMEM_FLAG_NO_WARNING;
+  suspend_warning = flags & GCRY_SECMEM_FLAG_SUSPEND_WARNING;
+
+  /* and now issue the warning if it is not longer suspended */
+  if (was_susp && !suspend_warning && show_warning)
+    {
+      show_warning = 0;
+      print_warn ();
+    }
+
+  SECMEM_UNLOCK;
+}
+
+unsigned
+_gcry_secmem_get_flags (void)
+{
+  unsigned flags;
+
+  SECMEM_LOCK;
+
+  flags = no_warning ? GCRY_SECMEM_FLAG_NO_WARNING : 0;
+  flags |= suspend_warning ? GCRY_SECMEM_FLAG_SUSPEND_WARNING : 0;
+
+  SECMEM_UNLOCK;
+
+  return flags;
+}
+
+/* Initialize the secure memory system.  If running with the necessary
+   privileges, the secure memory pool will be locked into the core in
+   order to prevent page-outs of the data.  Furthermore allocated
+   secure memory will be wiped out when released.  */
+void
+_gcry_secmem_init (size_t n)
+{
+  SECMEM_LOCK;
+
+  if (!n)
+    {
+#ifdef USE_CAPABILITIES
+      /* drop all capabilities */
+      cap_set_proc (cap_from_text ("all-eip"));
+
+#elif !defined(HAVE_DOSISH_SYSTEM)
+      uid_t uid;
+
+      disable_secmem = 1;
+      uid = getuid ();
+      if (uid != geteuid ())
+	{
+	  if (setuid (uid) || getuid () != geteuid () || !setuid (0))
+	    log_fatal ("failed to drop setuid\n");
+	}
+#endif
+    }
+  else
+    {
+      if (n < DEFAULT_POOL_SIZE)
+	n = DEFAULT_POOL_SIZE;
+      if (! pool_okay)
+	{
+	  init_pool (n);
+	  if (! geteuid ())
+	    lock_pool (pool, n);
+	  else if (!no_warning)
+	    log_info ("Secure memory is not locked into core\n");
+	}
+      else
+	log_error ("Oops, secure memory pool already initialized\n");
+    }
+
+  SECMEM_UNLOCK;
+}
+
+
+static void *
+_gcry_secmem_malloc_internal (size_t size)
+{
+  memblock_t *mb;
+
+  if (!pool_okay)
+    {
+      log_info (_
+	("operation is not possible without initialized secure memory\n"));
+      exit (2);
+    }
+  if (show_warning && !suspend_warning)
+    {
+      show_warning = 0;
+      print_warn ();
+    }
+
+  /* Blocks are always a multiple of 32. */
+  size = ((size + 31) / 32) * 32;
+
+  mb = mb_get_new ((memblock_t *) pool, size);
+  if (mb)
+    stats_update (size, 0);
+
+  return mb ? &mb->aligned.c : NULL;
+}
+
+void *
+_gcry_secmem_malloc (size_t size)
+{
+  void *p;
+
+  SECMEM_LOCK;
+  p = _gcry_secmem_malloc_internal (size);
+  SECMEM_UNLOCK;
+  
+  return p;
+}
+
+static void
+_gcry_secmem_free_internal (void *a)
+{
+  memblock_t *mb;
+  int size;
+
+  if (!a)
+    return;
+
+  mb = ADDR_TO_BLOCK (a);
+  size = mb->size;
+
+  /* This does not make much sense: probably this memory is held in the
+   * cache. We do it anyway: */
+#define MB_WIPE_OUT(byte) \
+  memset ((memblock_t *) ((char *) mb + BLOCK_HEAD_SIZE), (byte), size);
+
+  MB_WIPE_OUT (0xff);
+  MB_WIPE_OUT (0xaa);
+  MB_WIPE_OUT (0x55);
+  MB_WIPE_OUT (0x00);
+
+  stats_update (0, size);
+
+  mb->flags &= ~MB_FLAG_ACTIVE;
+
+  /* Update stats.  */
+
+  mb_merge (mb);
+}
+
+/* Wipe out and release memory.  */
+void
+_gcry_secmem_free (void *a)
+{
+  SECMEM_LOCK;
+  _gcry_secmem_free_internal (a);
+  SECMEM_UNLOCK;
+}
+
+/* Realloc memory.  */
+void *
+_gcry_secmem_realloc (void *p, size_t newsize)
+{
+  memblock_t *mb;
+  size_t size;
+  void *a;
+
+  SECMEM_LOCK;
+
+  mb = (memblock_t *) ((char *) p - ((size_t) &((memblock_t *) 0)->aligned.c));
+  size = mb->size;
+  if (newsize < size)
+    {
+      /* It is easier to not shrink the memory.  */
+      a = p;
+    }
+  else
+    {
+      a = _gcry_secmem_malloc_internal (newsize);
+      if (a)
+	{
+	  memcpy (a, p, size);
+	  memset ((char *) a + size, 0, newsize - size);
+	  _gcry_secmem_free_internal (p);
+	}
+    }
+
+  SECMEM_UNLOCK;
+
+  return a;
+}
+
+int
+_gcry_private_is_secure (const void *p)
+{
+  int ret = 0;
+
+  SECMEM_LOCK;
+
+  if (pool_okay && BLOCK_VALID (ADDR_TO_BLOCK (p)))
+    ret = 1;
+
+  SECMEM_UNLOCK;
+
+  return ret;
+}
+
+
+/****************
+ * Warning:  This code might be called by an interrupt handler
+ *	     and frankly, there should really be such a handler,
+ *	     to make sure that the memory is wiped out.
+ *	     We hope that the OS wipes out mlocked memory after
+ *	     receiving a SIGKILL - it really should do so, otherwise
+ *	     there is no chance to get the secure memory cleaned.
+ */
+void
+_gcry_secmem_term ()
+{
+  if (!pool_okay)
+    return;
+
+  wipememory2 (pool, 0xff, pool_size);
+  wipememory2 (pool, 0xaa, pool_size);
+  wipememory2 (pool, 0x55, pool_size);
+  wipememory2 (pool, 0x00, pool_size);
+#if HAVE_MMAP
+  if (pool_is_mmapped)
+    munmap (pool, pool_size);
+#endif
+  pool = NULL;
+  pool_okay = 0;
+  pool_size = 0;
+}
+
+
+void
+_gcry_secmem_dump_stats ()
+{
+#if 1 
+  SECMEM_LOCK;
+
+ if (pool_okay)
+    log_info ("secmem usage: %u/%lu bytes in %u blocks\n",
+	      cur_alloced, (unsigned long)pool_size, cur_blocks);
+  SECMEM_UNLOCK;
+#else
+  memblock_t *mb;
+  int i;
+
+  SECMEM_LOCK;
+
+  for (i = 0, mb = (memblock_t *) pool;
+       BLOCK_VALID (mb);
+       mb = mb_get_next (mb), i++)
+    log_info ("SECMEM: [%s] block: %i; size: %i\n",
+	      (mb->flags & MB_FLAG_ACTIVE) ? "used" : "free",
+	      i,
+	      mb->size);
+  SECMEM_UNLOCK;
+#endif
+}