1 files changed, 159 insertions, 0 deletions

diff --git a/src/contrib/service/secretsharing/secretsharing_common.c b/src/contrib/service/secretsharing/secretsharing_common.c
new file mode 100644
index 000000000..44b96b1c8
--- /dev/null
+++ b/src/contrib/service/secretsharing/secretsharing_common.c
@@ -0,0 +1,159 @@
+/*
+     This file is part of GNUnet.
+     Copyright (C) 2014 GNUnet e.V.
+
+     GNUnet is free software: you can redistribute it and/or modify it
+     under the terms of the GNU Affero General Public License as published
+     by the Free Software Foundation, either version 3 of the License,
+     or (at your option) any later version.
+
+     GNUnet 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
+     Affero General Public License for more details.
+
+     You should have received a copy of the GNU Affero General Public License
+     along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+     SPDX-License-Identifier: AGPL3.0-or-later
+ */
+
+#include "platform.h"
+#include "secretsharing.h"
+
+/**
+ * Read a share from its binary representation.
+ *
+ * @param data Binary representation of the share.
+ * @param len Length of @a data.
+ * @param[out] readlen Number of bytes read,
+ *             ignored if NULL.
+ * @return The share, or NULL on error.
+ */
+struct GNUNET_SECRETSHARING_Share *
+GNUNET_SECRETSHARING_share_read (const void *data,
+                                 size_t len,
+                                 size_t *readlen)
+{
+  struct GNUNET_SECRETSHARING_Share *share;
+  const struct GNUNET_SECRETSHARING_ShareHeaderNBO *sh = data;
+  const char *p;
+  size_t n;
+  uint16_t payload_size;
+
+  payload_size = ntohs (sh->num_peers)
+                 * (sizeof(uint16_t) + sizeof(struct
+                                              GNUNET_SECRETSHARING_FieldElement)
+                    + sizeof(struct GNUNET_PeerIdentity));
+
+  if (NULL != readlen)
+    *readlen = payload_size + sizeof *sh;
+
+  share = GNUNET_new (struct GNUNET_SECRETSHARING_Share);
+
+  share->threshold = ntohs (sh->threshold);
+  share->num_peers = ntohs (sh->num_peers);
+  share->my_peer = ntohs (sh->my_peer);
+
+  share->my_share = sh->my_share;
+  share->public_key = sh->public_key;
+
+  p = (const char *) &sh[1];
+
+  n = share->num_peers * sizeof(struct GNUNET_PeerIdentity);
+  share->peers = GNUNET_new_array (share->num_peers,
+                                   struct GNUNET_PeerIdentity);
+  GNUNET_memcpy (share->peers, p, n);
+  p += n;
+
+  n = share->num_peers * sizeof(struct GNUNET_SECRETSHARING_FieldElement);
+  share->sigmas = GNUNET_new_array (share->num_peers,
+                                    struct GNUNET_SECRETSHARING_FieldElement);
+  GNUNET_memcpy (share->sigmas, p, n);
+  p += n;
+
+  n = share->num_peers * sizeof(uint16_t);
+  share->original_indices = GNUNET_new_array (share->num_peers,
+                                              uint16_t);
+  GNUNET_memcpy (share->original_indices, p, n);
+
+  return share;
+}
+
+
+/**
+ * Convert a share to its binary representation.
+ * Can be called with a NULL @a buf to get the size of the share.
+ *
+ * @param share Share to write.
+ * @param buf Buffer to write to.
+ * @param buflen Number of writable bytes in @a buf.
+ * @param[out] writelen Pointer to store number of bytes written,
+ *             ignored if NULL.
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR on failure.
+ */
+int
+GNUNET_SECRETSHARING_share_write (const struct
+                                  GNUNET_SECRETSHARING_Share *share,
+                                  void *buf, size_t buflen, size_t *writelen)
+{
+  uint16_t payload_size;
+  struct GNUNET_SECRETSHARING_ShareHeaderNBO *sh;
+  char *p;
+  int n;
+
+  payload_size = share->num_peers
+                 * (sizeof(uint16_t) + sizeof(struct
+                                              GNUNET_SECRETSHARING_FieldElement)
+                    + sizeof(struct GNUNET_PeerIdentity));
+
+  if (NULL != writelen)
+    *writelen = payload_size + sizeof(struct
+                                      GNUNET_SECRETSHARING_ShareHeaderNBO);
+
+  /* just a query for the writelen */
+  if (buf == NULL)
+    return GNUNET_OK;
+
+  /* wrong buffer size */
+  if (buflen < payload_size + sizeof(struct
+                                     GNUNET_SECRETSHARING_ShareHeaderNBO))
+    return GNUNET_SYSERR;
+
+  sh = buf;
+
+  sh->threshold = htons (share->threshold);
+  sh->num_peers = htons (share->num_peers);
+  sh->my_peer = htons (share->my_peer);
+
+  sh->my_share = share->my_share;
+  sh->public_key = share->public_key;
+
+  p = (void *) &sh[1];
+
+  n = share->num_peers * sizeof(struct GNUNET_PeerIdentity);
+  GNUNET_memcpy (p, share->peers, n);
+  p += n;
+
+  n = share->num_peers * sizeof(struct GNUNET_SECRETSHARING_FieldElement);
+  GNUNET_memcpy (p, share->sigmas, n);
+  p += n;
+
+  n = share->num_peers * sizeof(uint16_t);
+  GNUNET_memcpy (p, share->original_indices, n);
+
+  return GNUNET_OK;
+}
+
+
+void
+GNUNET_SECRETSHARING_share_destroy (struct GNUNET_SECRETSHARING_Share *share)
+{
+  GNUNET_free (share->original_indices);
+  share->original_indices = NULL;
+  GNUNET_free (share->sigmas);
+  share->sigmas = NULL;
+  GNUNET_free (share->peers);
+  share->peers = NULL;
+  GNUNET_free (share);
+}