1 files changed, 215 insertions, 0 deletions

diff --git a/src/credential/credential_serialization.c b/src/credential/credential_serialization.c
new file mode 100644
index 000000000..2fbcebd9f
--- /dev/null
+++ b/src/credential/credential_serialization.c
@@ -0,0 +1,215 @@
+/*
+     This file is part of GNUnet.
+     Copyright (C) 2009-2013, 2016 GNUnet e.V.
+
+     GNUnet is free software; you can redistribute it and/or modify
+     it under the terms of the GNU General Public License as published
+     by the Free Software Foundation; either version 3, 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
+     General Public License for more details.
+
+     You should have received a copy of the GNU General Public License
+     along with GNUnet; see the file COPYING.  If not, write to the
+     Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+     Boston, MA 02110-1301, USA.
+*/
+
+
+/**
+ * @file credential/credential_serialization.c
+ * @brief API to serialize and deserialize delegation chains 
+ * and credentials
+ * @author Martin Schanzenbach
+ */
+#include "platform.h"
+#include "gnunet_util_lib.h"
+#include "gnunet_constants.h"
+#include "gnunet_credential_service.h"
+
+GNUNET_NETWORK_STRUCT_BEGIN
+
+struct NetworkRecord
+{
+  /**
+   * Issuer key
+   */
+  struct GNUNET_CRYPTO_EcdsaPublicKey issuer_key;
+  
+  /**
+   * Subject key
+   */
+  struct GNUNET_CRYPTO_EcdsaPublicKey subject_key;
+  
+  /**
+   * Issuer attributes
+   */
+  uint32_t issuer_attribute_len GNUNET_PACKED;
+  
+  /**
+   * Subject attributes
+   */
+  uint32_t subject_attribute_len GNUNET_PACKED;
+};
+
+GNUNET_NETWORK_STRUCT_END
+
+/**
+ * Calculate how many bytes we will need to serialize
+ * the given delegation chain and credential
+ *
+ * @param d_count number of delegation chain entries
+ * @param dd array of #GNUNET_CREDENTIAL_Delegation
+ * @param cd a #GNUNET_CREDENTIAL_Credential
+ * @return the required size to serialize
+ */
+size_t
+GNUNET_CREDENTIAL_delegation_chain_get_size (unsigned int d_count,
+                                             const struct GNUNET_CREDENTIAL_Delegation *dd,
+                                             const struct GNUNET_CREDENTIAL_Credential *cd)
+{
+  unsigned int i;
+  size_t ret;
+
+  ret = sizeof (struct NetworkRecord) * (d_count + 1);
+
+  for (i=0; i<d_count;i++)
+  {
+    GNUNET_assert ((ret +
+                    dd[i].issuer_attribute_len +
+                    dd[i].subject_attribute_len) >= ret);
+    ret += dd[i].issuer_attribute_len + dd[i].subject_attribute_len;
+  }
+  GNUNET_assert ((ret + cd->issuer_attribute_len) >= ret);
+  ret += cd->issuer_attribute_len;
+  return ret;
+}
+
+/**
+ * Serizalize the given delegation chain entries and credential
+ *
+ * @param d_count number of delegation chain entries
+ * @param dd array of #GNUNET_CREDENTIAL_Delegation
+ * @param cd a #GNUNET_CREDENTIAL_Credential
+ * @param dest_size size of the destination
+ * @param dest where to store the result
+ * @return the size of the data, -1 on failure
+ */
+ssize_t
+GNUNET_CREDENTIAL_delegation_chain_serialize (unsigned int d_count,
+                                              const struct GNUNET_CREDENTIAL_Delegation *dd,
+                                              const struct GNUNET_CREDENTIAL_Credential *cd,
+                                              size_t dest_size,
+                                              char *dest)
+{
+  struct NetworkRecord rec;
+  unsigned int i;
+  size_t off;
+
+  off = 0;
+  for (i=0;i<d_count;i++)
+  {
+    rec.issuer_attribute_len = htonl ((uint32_t) dd[i].issuer_attribute_len);
+    rec.subject_attribute_len = htonl ((uint32_t) dd[i].subject_attribute_len);
+    rec.issuer_key = dd[i].issuer_key;
+    rec.subject_key = dd[i].subject_key;
+    if (off + sizeof (rec) > dest_size)
+      return -1;
+    GNUNET_memcpy (&dest[off],
+                   &rec,
+                   sizeof (rec));
+    off += sizeof (rec);
+    if (off + dd[i].issuer_attribute_len > dest_size)
+      return -1;
+    GNUNET_memcpy (&dest[off],
+                   dd[i].issuer_attribute,
+                   dd[i].issuer_attribute_len);
+    off += dd[i].issuer_attribute_len;
+    if (0 == dd[i].subject_attribute_len)
+      continue;
+    if (off + dd[i].subject_attribute_len > dest_size)
+      return -1;
+    GNUNET_memcpy (&dest[off],
+                   dd[i].subject_attribute,
+                   dd[i].subject_attribute_len);
+    off += dd[i].subject_attribute_len;
+  }
+  rec.issuer_attribute_len = htonl ((uint32_t) cd->issuer_attribute_len);
+  rec.subject_attribute_len = htonl (0);
+  rec.issuer_key = cd->issuer_key;
+  if (off + sizeof (rec) > dest_size)
+    return -1;
+  GNUNET_memcpy (&dest[off],
+                 &rec,
+                 sizeof (rec));
+  off += sizeof (rec);
+  if (off + cd->issuer_attribute_len > dest_size)
+    return -1;
+  GNUNET_memcpy (&dest[off],
+                 cd->issuer_attribute,
+                 cd->issuer_attribute_len);
+  off += cd->issuer_attribute_len;
+
+  return off;
+}
+
+
+/**
+ * Deserialize the given destination
+ *
+ * @param len size of the serialized delegation chain and cred
+ * @param src the serialized data
+ * @param d_count the number of delegation chain entries
+ * @param dd where to put the delegation chain entries
+ * @param cd where to put the credential data
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
+ */
+int
+GNUNET_CREDENTIAL_delegation_chain_deserialize (size_t len,
+                                                const char *src,
+                                                unsigned int d_count,
+                                                struct GNUNET_CREDENTIAL_Delegation *dd,
+                                                struct GNUNET_CREDENTIAL_Credential *cd)
+{
+  struct NetworkRecord rec;
+  unsigned int i;
+  size_t off;
+
+  off = 0;
+  for (i=0;i<d_count;i++)
+  {
+    if (off + sizeof (rec) > len)
+      return GNUNET_SYSERR;
+    GNUNET_memcpy (&rec, &src[off], sizeof (rec));
+    dd[i].issuer_attribute_len = ntohl ((uint32_t) rec.issuer_attribute_len);
+    dd[i].issuer_key = rec.issuer_key;
+    dd[i].subject_key = rec.subject_key;
+    off += sizeof (rec);
+    if (off + dd[i].issuer_attribute_len > len)
+      return GNUNET_SYSERR;
+    dd[i].issuer_attribute = &src[off];
+    off += dd[i].issuer_attribute_len;
+    dd[i].subject_attribute_len = ntohl ((uint32_t) rec.subject_attribute_len);
+    if (off + dd[i].subject_attribute_len > len)
+      return GNUNET_SYSERR;
+    dd[i].subject_attribute = &src[off];
+    off += dd[i].subject_attribute_len;
+  }
+  if (off + sizeof (rec) > len)
+    return GNUNET_SYSERR;
+  GNUNET_memcpy (&rec, &src[off], sizeof (rec));
+  cd->issuer_attribute_len = ntohl ((uint32_t) rec.issuer_attribute_len);
+  cd->issuer_key = rec.issuer_key;
+  cd->subject_key = rec.subject_key;
+  off += sizeof (rec);
+  if (off + cd->issuer_attribute_len > len)
+    return GNUNET_SYSERR;
+  cd->issuer_attribute = &src[off];
+  off += cd->issuer_attribute_len;
+  return GNUNET_OK;
+}
+
+/* end of credential_serialization.c */