Adding upstream version 2.2.40.upstream/2.2.40upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 233 insertions, 0 deletions

diff --git a/common/membuf.c b/common/membuf.c
new file mode 100644
index 0000000..009fbc3
--- /dev/null
+++ b/common/membuf.c
@@ -0,0 +1,233 @@
+/* membuf.c - A simple implementation of a dynamic buffer.
+ * Copyright (C) 2001, 2003, 2009, 2011 Free Software Foundation, Inc.
+ * Copyright (C) 2013 Werner Koch
+ *
+ * This file is part of GnuPG.
+ *
+ * This file is free software; you can redistribute it and/or modify
+ * it under the terms of either
+ *
+ *   - the GNU Lesser General Public License as published by the Free
+ *     Software Foundation; either version 3 of the License, or (at
+ *     your option) any later version.
+ *
+ * or
+ *
+ *   - 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.
+ *
+ * or both in parallel, as here.
+ *
+ * This file 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, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <stdarg.h>
+
+#include "util.h"
+#include "membuf.h"
+
+
+/* A simple implementation of a dynamic buffer.  Use init_membuf() to
+   create a buffer, put_membuf to append bytes and get_membuf to
+   release and return the buffer.  Allocation errors are detected but
+   only returned at the final get_membuf(), this helps not to clutter
+   the code with out of core checks.  */
+
+void
+init_membuf (membuf_t *mb, int initiallen)
+{
+  mb->len = 0;
+  mb->size = initiallen;
+  mb->out_of_core = 0;
+  mb->buf = xtrymalloc (initiallen);
+  if (!mb->buf)
+    mb->out_of_core = errno;
+}
+
+/* Same as init_membuf but allocates the buffer in secure memory.  */
+void
+init_membuf_secure (membuf_t *mb, int initiallen)
+{
+  mb->len = 0;
+  mb->size = initiallen;
+  mb->out_of_core = 0;
+  mb->buf = xtrymalloc_secure (initiallen);
+  if (!mb->buf)
+    mb->out_of_core = errno;
+}
+
+
+/* Shift the content of the membuf MB by AMOUNT bytes.  The next
+   operation will then behave as if AMOUNT bytes had not been put into
+   the buffer.  If AMOUNT is greater than the actual accumulated
+   bytes, the membuf is basically reset to its initial state.  */
+void
+clear_membuf (membuf_t *mb, size_t amount)
+{
+  /* No need to clear if we are already out of core.  */
+  if (mb->out_of_core)
+    return;
+  if (amount >= mb->len)
+    mb->len = 0;
+  else
+    {
+      mb->len -= amount;
+      memmove (mb->buf, mb->buf+amount, mb->len);
+    }
+}
+
+
+void
+put_membuf (membuf_t *mb, const void *buf, size_t len)
+{
+  if (mb->out_of_core || !len)
+    return;
+
+  if (mb->len + len >= mb->size)
+    {
+      char *p;
+
+      mb->size += len + 1024;
+      p = xtryrealloc (mb->buf, mb->size);
+      if (!p)
+        {
+          mb->out_of_core = errno ? errno : ENOMEM;
+          /* Wipe out what we already accumulated.  This is required
+             in case we are storing sensitive data here.  The membuf
+             API does not provide another way to cleanup after an
+             error. */
+          wipememory (mb->buf, mb->len);
+          return;
+        }
+      mb->buf = p;
+    }
+  if (buf)
+    memcpy (mb->buf + mb->len, buf, len);
+  else
+    memset (mb->buf + mb->len, 0, len);
+  mb->len += len;
+}
+
+
+/* A variant of put_membuf accepting a void * and returning a
+   gpg_error_t (which will always return 0) to be used as a generic
+   callback handler.  This function also allows buffer to be NULL.  */
+gpg_error_t
+put_membuf_cb (void *opaque, const void *buf, size_t len)
+{
+  membuf_t *data = opaque;
+
+  if (buf)
+    put_membuf (data, buf, len);
+  return 0;
+}
+
+
+void
+put_membuf_str (membuf_t *mb, const char *string)
+{
+  put_membuf (mb, string, strlen (string));
+}
+
+
+void
+put_membuf_printf (membuf_t *mb, const char *format, ...)
+{
+  int rc;
+  va_list arg_ptr;
+  char *buf;
+
+  va_start (arg_ptr, format);
+  rc = gpgrt_vasprintf (&buf, format, arg_ptr);
+  if (rc < 0)
+    mb->out_of_core = errno ? errno : ENOMEM;
+  va_end (arg_ptr);
+  if (rc >= 0)
+    {
+      put_membuf (mb, buf, strlen (buf));
+      xfree (buf);
+    }
+}
+
+
+void *
+get_membuf (membuf_t *mb, size_t *len)
+{
+  char *p;
+
+  if (mb->out_of_core)
+    {
+      if (mb->buf)
+        {
+          wipememory (mb->buf, mb->len);
+          xfree (mb->buf);
+          mb->buf = NULL;
+        }
+      gpg_err_set_errno (mb->out_of_core);
+      return NULL;
+    }
+
+  p = mb->buf;
+  if (len)
+    *len = mb->len;
+  mb->buf = NULL;
+  mb->out_of_core = ENOMEM; /* hack to make sure it won't get reused. */
+  return p;
+}
+
+
+/* Same as get_membuf but shrinks the reallocated space to the
+   required size.  */
+void *
+get_membuf_shrink (membuf_t *mb, size_t *len)
+{
+  void *p, *pp;
+  size_t dummylen;
+
+  if (!len)
+    len = &dummylen;
+
+  p = get_membuf (mb, len);
+  if (!p)
+    return NULL;
+  if (*len)
+    {
+      pp = xtryrealloc (p, *len);
+      if (pp)
+        p = pp;
+    }
+
+  return p;
+}
+
+
+/* Peek at the membuf MB.  On success a pointer to the buffer is
+   returned which is valid until the next operation on MB.  If LEN is
+   not NULL the current LEN of the buffer is stored there.  On error
+   NULL is returned and ERRNO is set.  */
+const void *
+peek_membuf (membuf_t *mb, size_t *len)
+{
+  const char *p;
+
+  if (mb->out_of_core)
+    {
+      gpg_err_set_errno (mb->out_of_core);
+      return NULL;
+    }
+
+  p = mb->buf;
+  if (len)
+    *len = mb->len;
+  return p;
+}