Adapted JSON Conversion and Serialization

7 files changed, 670 insertions, 0 deletions

diff --git a/src/include/gnunet_reclaim_attribute_lib.h b/src/include/gnunet_reclaim_attribute_lib.h
index 4563a5f67..c23b39383 100644
--- a/src/include/gnunet_reclaim_attribute_lib.h
+++ b/src/include/gnunet_reclaim_attribute_lib.h
@@ -50,6 +50,15 @@ extern "C" {
  */
 #define GNUNET_RECLAIM_ATTRIBUTE_TYPE_STRING 1
 
+/**
+* No value attestation.
+*/
+#define GNUNET_RECLAIM_ATTESTATION_TYPE_NONE 0
+
+/**
+* A JSON Web Token attestation.
+*/
+#define GNUNET_RECLAIM_ATTESTATION_TYPE_JWT 1
 
 /**
  * An attribute.
@@ -89,6 +98,44 @@ struct GNUNET_RECLAIM_ATTRIBUTE_Claim
   const void *data;
 };
 
+/**
+ * An attestation.
+ */
+struct GNUNET_RECLAIM_ATTESTATION_Claim
+{
+  /**
+   * ID
+   */
+  uint64_t id;
+
+  /**
+   * Type/Format of Claim
+   */
+  uint32_t type;
+
+  /**
+   * Version
+   */
+  uint32_t version;
+
+  /**
+   * The name of the attribute. Note "name" must never be individually
+   * free'd
+   */
+  const char *name;
+
+  /**
+   * Number of bytes in @e data.
+   */
+  size_t data_size;
+
+  /**
+   * Binary value stored as attribute value.  Note: "data" must never
+   * be individually 'malloc'ed, but instead always points into some
+   * existing data area.
+   */
+  const void *data;
+};
 
 /**
  * A list of GNUNET_RECLAIM_ATTRIBUTE_Claim structures.
@@ -299,6 +346,103 @@ GNUNET_RECLAIM_ATTRIBUTE_value_to_string (uint32_t type,
 const char *
 GNUNET_RECLAIM_ATTRIBUTE_number_to_typename (uint32_t type);
 
+/**
+   * Get required size for serialization buffer
+   *
+   * @param attr the attestation to serialize
+   * @return the required buffer size
+   */
+size_t
+GNUNET_RECLAIM_ATTESTATION_serialize_get_size (
+  const struct GNUNET_RECLAIM_ATTESTATION_Claim *attr);
+
+
+/**
+ * Serialize an attestation
+ *
+ * @param attr the attestation to serialize
+ * @param result the serialized attestation
+ * @return length of serialized data
+ */
+size_t
+GNUNET_RECLAIM_ATTESTATION_serialize (
+  const struct GNUNET_RECLAIM_ATTESTATION_Claim *attr,
+  char *result);
+
+
+/**
+ * Deserialize an attestation
+ *
+ * @param data the serialized attestation
+ * @param data_size the length of the serialized data
+ *
+ * @return a GNUNET_IDENTITY_PROVIDER_Attribute, must be free'd by caller
+ */
+struct GNUNET_RECLAIM_ATTESTATION_Claim *
+GNUNET_RECLAIM_ATTESTATION_deserialize (const char *data, size_t data_size);
+
+
+/**
+   * Create a new attestation.
+   *
+   * @param attr_name the attestation name
+   * @param type the attestation type
+   * @param data the attestation value
+   * @param data_size the attestation value size
+   * @return the new attestation
+   */
+struct GNUNET_RECLAIM_ATTESTATION_Claim *
+GNUNET_RECLAIM_ATTESTATION_claim_new (const char *attr_name,
+                                      uint32_t type,
+                                      const void *data,
+                                      size_t data_size);
+
+/**
+ * Convert the 'claim' of an attestation to a string
+ *
+ * @param type the type of attestation
+ * @param data claim in binary encoding
+ * @param data_size number of bytes in @a data
+ * @return NULL on error, otherwise human-readable representation of the claim
+ */
+char *
+GNUNET_RECLAIM_ATTESTATION_value_to_string (uint32_t type,
+                                            const void *data,
+                                            size_t data_size);
+
+/**
+ * Convert human-readable version of a 'claim' of an attestation to the binary
+ * representation
+ *
+ * @param type type of the claim
+ * @param s human-readable string
+ * @param data set to value in binary encoding (will be allocated)
+ * @param data_size set to number of bytes in @a data
+ * @return #GNUNET_OK on success
+ */
+int
+GNUNET_RECLAIM_ATTESTATION_string_to_value (uint32_t type,
+                                            const char *s,
+                                            void **data,
+                                            size_t *data_size);
+
+/**
+ * Convert an attestation type number to the corresponding attestation type string
+ *
+ * @param type number of a type
+ * @return corresponding typestring, NULL on error
+ */
+const char *
+GNUNET_RECLAIM_ATTESTATION_number_to_typename (uint32_t type);
+
+/**
+ * Convert an attestation type name to the corresponding number
+ *
+ * @param typename name to convert
+ * @return corresponding number, UINT32_MAX on error
+ */
+uint32_t
+GNUNET_RECLAIM_ATTESTATION_typename_to_number (const char *typename);
 
 #if 0 /* keep Emacsens' auto-indent happy */
 {
diff --git a/src/include/gnunet_reclaim_attribute_plugin.h b/src/include/gnunet_reclaim_attribute_plugin.h
index 26a4bb4f2..bdd815dcf 100644
--- a/src/include/gnunet_reclaim_attribute_plugin.h
+++ b/src/include/gnunet_reclaim_attribute_plugin.h
@@ -134,6 +134,27 @@ struct GNUNET_RECLAIM_ATTRIBUTE_PluginFunctions
    * Number to typename.
    */
   GNUNET_RECLAIM_ATTRIBUTE_NumberToTypenameFunction number_to_typename;
+
+  /**
+* Attestation Conversion to string.
+*/
+  GNUNET_RECLAIM_ATTRIBUTE_ValueToStringFunction value_to_string_attest;
+
+  /**
+  * Attestation Conversion to binary.
+  */
+  GNUNET_RECLAIM_ATTRIBUTE_StringToValueFunction string_to_value_attest;
+
+  /**
+  * Attestation Typename to number.
+  */
+  GNUNET_RECLAIM_ATTRIBUTE_TypenameToNumberFunction typename_to_number_attest;
+
+  /**
+  * Attestation Number to typename.
+  */
+  GNUNET_RECLAIM_ATTRIBUTE_NumberToTypenameFunction number_to_typename_attest;
+
 };
 
 
diff --git a/src/reclaim-attribute/plugin_reclaim_attribute_gnuid.c b/src/reclaim-attribute/plugin_reclaim_attribute_gnuid.c
index bb60909d9..37610e2fb 100644
--- a/src/reclaim-attribute/plugin_reclaim_attribute_gnuid.c
+++ b/src/reclaim-attribute/plugin_reclaim_attribute_gnuid.c
@@ -90,6 +90,63 @@ gnuid_string_to_value (void *cls,
   }
 }
 
+/**
+   * Convert the 'value' of an attestation to a string.
+   *
+   * @param cls closure, unused
+   * @param type type of the attestation
+   * @param data value in binary encoding
+   * @param data_size number of bytes in @a data
+   * @return NULL on error, otherwise human-readable representation of the value
+   */
+static char *
+gnuid_value_to_string_attest (void *cls,
+                              uint32_t type,
+                              const void *data,
+                              size_t data_size)
+{
+  switch (type)
+  {
+  case GNUNET_RECLAIM_ATTESTATION_TYPE_JWT:
+    return GNUNET_strndup (data, data_size);
+
+  default:
+    return NULL;
+  }
+}
+
+
+/**
+ * Convert human-readable version of a 'value' of an attestation to the binary
+ * representation.
+ *
+ * @param cls closure, unused
+ * @param type type of the attestation
+ * @param s human-readable string
+ * @param data set to value in binary encoding (will be allocated)
+ * @param data_size set to number of bytes in @a data
+ * @return #GNUNET_OK on success
+ */
+static int
+gnuid_string_to_value_attest (void *cls,
+                              uint32_t type,
+                              const char *s,
+                              void **data,
+                              size_t *data_size)
+{
+  if (NULL == s)
+    return GNUNET_SYSERR;
+  switch (type)
+  {
+  case GNUNET_RECLAIM_ATTESTATION_TYPE_JWT:
+    *data = GNUNET_strdup (s);
+    *data_size = strlen (s);
+    return GNUNET_OK;
+
+  default:
+    return GNUNET_SYSERR;
+  }
+}
 
 /**
  * Mapping of attribute type numbers to human-readable
@@ -102,6 +159,17 @@ static struct
 } gnuid_name_map[] = { { "STRING", GNUNET_RECLAIM_ATTRIBUTE_TYPE_STRING },
                        { NULL, UINT32_MAX } };
 
+/**
+   * Mapping of attribute type numbers to human-readable
+   * attribute type names.
+   */
+static struct
+{
+  const char *name;
+  uint32_t number;
+} gnuid_attest_name_map[] = { { "STRING",
+                                GNUNET_RECLAIM_ATTRIBUTE_TYPE_STRING },
+                              { NULL, UINT32_MAX } };
 
 /**
  * Convert a type name to the corresponding number.
@@ -141,6 +209,44 @@ gnuid_number_to_typename (void *cls, uint32_t type)
   return gnuid_name_map[i].name;
 }
 
+/**
+   * Convert a type name to the corresponding number.
+   *
+   * @param cls closure, unused
+   * @param gnuid_typename name to convert
+   * @return corresponding number, UINT32_MAX on error
+   */
+static uint32_t
+gnuid_typename_to_number_attest (void *cls, const char *gnuid_typename)
+{
+  unsigned int i;
+
+  i = 0;
+  while ((NULL != gnuid_attest_name_map[i].name) &&
+         (0 != strcasecmp (gnuid_typename, gnuid_attest_name_map[i].name)))
+    i++;
+  return gnuid_attest_name_map[i].number;
+}
+
+/**
+ * Convert a type number (i.e. 1) to the corresponding type string
+ *
+ * @param cls closure, unused
+ * @param type number of a type to convert
+ * @return corresponding typestring, NULL on error
+ */
+static const char *
+gnuid_number_to_typename (void *cls, uint32_t type)
+{
+  unsigned int i;
+
+  i = 0;
+  while ((NULL != gnuid_attest_name_map[i].name) && (type !=
+                                                     gnuid_attest_name_map[i].
+                                                     number))
+    i++;
+  return gnuid_attest_name_map[i].name;
+}
 
 /**
  * Entry point for the plugin.
@@ -158,6 +264,10 @@ libgnunet_plugin_reclaim_attribute_gnuid_init (void *cls)
   api->string_to_value = &gnuid_string_to_value;
   api->typename_to_number = &gnuid_typename_to_number;
   api->number_to_typename = &gnuid_number_to_typename;
+  api->value_to_string_attest = &gnuid_value_to_string_attest;
+  api->string_to_value_attest = &gnuid_string_to_value_attest;
+  api->typename_to_number_attest = &gnuid_typename_to_number_attest;
+  api->number_to_typename_attest = &gnuid_number_to_typename_attest;
   return api;
 }
 
diff --git a/src/reclaim-attribute/reclaim_attribute.c b/src/reclaim-attribute/reclaim_attribute.c
index b81394ad2..6dd1632fd 100644
--- a/src/reclaim-attribute/reclaim_attribute.c
+++ b/src/reclaim-attribute/reclaim_attribute.c
@@ -217,6 +217,117 @@ GNUNET_RECLAIM_ATTRIBUTE_value_to_string (uint32_t type,
   return NULL;
 }
 
+/**
+   * Convert an attestation type name to the corresponding number
+   *
+   * @param typename name to convert
+   * @return corresponding number, UINT32_MAX on error
+   */
+uint32_t
+GNUNET_RECLAIM_ATTESTATION_typename_to_number (const char *typename)
+{
+  unsigned int i;
+  struct Plugin *plugin;
+  uint32_t ret;
+
+  init ();
+  for (i = 0; i < num_plugins; i++)
+  {
+    plugin = attr_plugins[i];
+    if (UINT32_MAX !=
+        (ret = plugin->api->typename_to_number_attest (plugin->api->cls,
+                                                       typename)))
+      return ret;
+  }
+  return UINT32_MAX;
+}
+
+/**
+ * Convert an attestation type number to the corresponding attestation type string
+ *
+ * @param type number of a type
+ * @return corresponding typestring, NULL on error
+ */
+const char *
+GNUNET_RECLAIM_ATTESTATION_number_to_typename (uint32_t type)
+{
+  unsigned int i;
+  struct Plugin *plugin;
+  const char *ret;
+
+  init ();
+  for (i = 0; i < num_plugins; i++)
+  {
+    plugin = attr_plugins[i];
+    if (NULL !=
+        (ret = plugin->api->number_to_typename_attest (plugin->api->cls, type)))
+      return ret;
+  }
+  return NULL;
+}
+/**
+ * Convert human-readable version of a 'claim' of an attestation to the binary
+ * representation
+ *
+ * @param type type of the claim
+ * @param s human-readable string
+ * @param data set to value in binary encoding (will be allocated)
+ * @param data_size set to number of bytes in @a data
+ * @return #GNUNET_OK on success
+ */
+int
+GNUNET_RECLAIM_ATTESTATION_string_to_value (uint32_t type,
+                                            const char *s,
+                                            void **data,
+                                            size_t *data_size)
+{
+  unsigned int i;
+  struct Plugin *plugin;
+
+  init ();
+  for (i = 0; i < num_plugins; i++)
+  {
+    plugin = attr_plugins[i];
+    if (GNUNET_OK == plugin->api->string_to_value_attest (plugin->api->cls,
+                                                          type,
+                                                          s,
+                                                          data,
+                                                          data_size))
+      return GNUNET_OK;
+  }
+  return GNUNET_SYSERR;
+}
+
+
+/**
+ * Convert the 'claim' of an attestation to a string
+ *
+ * @param type the type of attestation
+ * @param data claim in binary encoding
+ * @param data_size number of bytes in @a data
+ * @return NULL on error, otherwise human-readable representation of the claim
+ */
+char *
+GNUNET_RECLAIM_ATTESTATION_value_to_string (uint32_t type,
+                                            const void *data,
+                                            size_t data_size)
+{
+  unsigned int i;
+  struct Plugin *plugin;
+  char *ret;
+
+  init ();
+  for (i = 0; i < num_plugins; i++)
+  {
+    plugin = attr_plugins[i];
+    if (NULL != (ret = plugin->api->value_to_string_attest (plugin->api->cls,
+                                                            type,
+                                                            data,
+                                                            data_size)))
+      return ret;
+  }
+  return NULL;
+}
 
 /**
  * Create a new attribute.
@@ -254,6 +365,41 @@ GNUNET_RECLAIM_ATTRIBUTE_claim_new (const char *attr_name,
   return attr;
 }
 
+/**
+   * Create a new attestation.
+   *
+   * @param attr_name the attestation name
+   * @param type the attestation type
+   * @param data the attestation value
+   * @param data_size the attestation value size
+   * @return the new attestation
+   */
+struct GNUNET_RECLAIM_ATTESTATION_Claim *
+GNUNET_RECLAIM_ATTESTATION_claim_new (const char *attr_name,
+                                      uint32_t type,
+                                      const void *data,
+                                      size_t data_size)
+{
+  struct GNUNET_RECLAIM_ATTESTATION_Claim *attr;
+  char *write_ptr;
+  char *attr_name_tmp = GNUNET_strdup (attr_name);
+
+  GNUNET_STRINGS_utf8_tolower (attr_name, attr_name_tmp);
+
+  attr = GNUNET_malloc (sizeof(struct GNUNET_RECLAIM_ATTESTATION_Claim)
+                        + strlen (attr_name_tmp) + 1 + data_size);
+  attr->type = type;
+  attr->data_size = data_size;
+  attr->version = 0;
+  write_ptr = (char *) &attr[1];
+  GNUNET_memcpy (write_ptr, attr_name_tmp, strlen (attr_name_tmp) + 1);
+  attr->name = write_ptr;
+  write_ptr += strlen (attr->name) + 1;
+  GNUNET_memcpy (write_ptr, data, data_size);
+  attr->data = write_ptr;
+  GNUNET_free (attr_name_tmp);
+  return attr;
+}
 
 /**
  * Add a new attribute to a claim list
@@ -521,4 +667,100 @@ GNUNET_RECLAIM_ATTRIBUTE_deserialize (const char *data, size_t data_size)
 }
 
 
+/**
+ * Get required size for serialization buffer
+ *
+ * @param attr the attestation to serialize
+ * @return the required buffer size
+ */
+size_t
+GNUNET_RECLAIM_ATTESTATION_serialize_get_size (
+  const struct GNUNET_RECLAIM_ATTESTATION_Claim *attr)
+{
+  return sizeof(struct Attestation) + strlen (attr->name) + attr->data_size;
+}
+
+/**
+ * Serialize an attestation
+ *
+ * @param attr the attestation to serialize
+ * @param result the serialized attestation
+ * @return length of serialized data
+ */
+size_t
+GNUNET_RECLAIM_ATTESTATION_serialize (
+  const struct GNUNET_RECLAIM_ATTESTATION_Claim *attr,
+  char *result)
+{
+  size_t data_len_ser;
+  size_t name_len;
+  struct Attestation *attr_ser;
+  char *write_ptr;
+
+  attr_ser = (struct Attestation *) result;
+  attr_ser->attestation_type = htons (attr->type);
+  attr_ser->attestation_type = htonl (attr->version);
+  attr_ser->attestation_type = GNUNET_htonll (attr->id);
+  name_len = strlen (attr->name);
+  attr_ser->name_len = htons (name_len);
+  write_ptr = (char *) &attr_ser[1];
+  GNUNET_memcpy (write_ptr, attr->name, name_len);
+  write_ptr += name_len;
+  // TODO plugin-ize
+  // data_len_ser = plugin->serialize_attribute_value (attr,
+  //                                                  &attr_ser[1]);
+  data_len_ser = attr->data_size;
+  GNUNET_memcpy (write_ptr, attr->data, attr->data_size);
+  attr_ser->data_size = htons (data_len_ser);
+
+  return sizeof(struct Attestation) + strlen (attr->name) + attr->data_size;
+}
+
+/**
+ * Deserialize an attestation
+ *
+ * @param data the serialized attestation
+ * @param data_size the length of the serialized data
+ *
+ * @return a GNUNET_IDENTITY_PROVIDER_Attribute, must be free'd by caller
+ */
+struct GNUNET_RECLAIM_ATTESTATION_Claim *
+GNUNET_RECLAIM_ATTESTATION_deserialize (const char *data, size_t data_size)
+{
+  struct GNUNET_RECLAIM_ATTESTATION_Claim *attr;
+  struct Attestation *attr_ser;
+  size_t data_len;
+  size_t name_len;
+  char *write_ptr;
+
+  if (data_size < sizeof(struct Attestation))
+    return NULL;
+
+  attr_ser = (struct Attestation *) data;
+  data_len = ntohs (attr_ser->data_size);
+  name_len = ntohs (attr_ser->name_len);
+  if (data_size < sizeof(struct Attestation) + data_len + name_len)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Buffer too small to deserialize\n");
+    return NULL;
+  }
+  attr = GNUNET_malloc (sizeof(struct GNUNET_RECLAIM_ATTESTATION_Claim)
+                        + data_len + name_len + 1);
+  attr->type = ntohs (attr_ser->attestation_type);
+  attr->version = ntohl (attr_ser->attestation_version);
+  attr->id = GNUNET_ntohll (attr_ser->attestation_id);
+  attr->data_size = data_len;
+
+  write_ptr = (char *) &attr[1];
+  GNUNET_memcpy (write_ptr, &attr_ser[1], name_len);
+  write_ptr[name_len] = '\0';
+  attr->name = write_ptr;
+
+  write_ptr += name_len + 1;
+  GNUNET_memcpy (write_ptr, (char *) &attr_ser[1] + name_len, attr->data_size);
+  attr->data = write_ptr;
+  return attr;
+}
+
 /* end of reclaim_attribute.c */
diff --git a/src/reclaim-attribute/reclaim_attribute.h b/src/reclaim-attribute/reclaim_attribute.h
index d7358847e..750afc479 100644
--- a/src/reclaim-attribute/reclaim_attribute.h
+++ b/src/reclaim-attribute/reclaim_attribute.h
@@ -61,4 +61,37 @@ struct Attribute
   // followed by data_size Attribute value data
 };
 
+/**
+ * Serialized attestation claim
+ */
+struct Attestation
+{
+  /**
+   * Attestation type
+   */
+  uint32_t attestation_type;
+
+  /**
+   * Attestation version
+   */
+  uint32_t attestation_version;
+
+  /**
+   * Attestation ID
+   */
+  uint64_t attestation_id;
+
+  /**
+   * Name length
+   */
+  uint32_t name_len;
+
+  /**
+   * Data size
+   */
+  uint32_t data_size;
+
+  // followed by data_size Attestation value data
+};
+
 #endif
diff --git a/src/reclaim/json_reclaim.c b/src/reclaim/json_reclaim.c
index e029fdfb6..a0016bac8 100644
--- a/src/reclaim/json_reclaim.c
+++ b/src/reclaim/json_reclaim.c
@@ -264,3 +264,113 @@ GNUNET_RECLAIM_JSON_spec_ticket (struct GNUNET_RECLAIM_Ticket **ticket)
   *ticket = NULL;
   return ret;
 }
+
+/**
+   * Parse given JSON object to an attestation claim
+   *
+   * @param cls closure, NULL
+   * @param root the json object representing data
+   * @param spec where to write the data
+   * @return #GNUNET_OK upon successful parsing; #GNUNET_SYSERR upon error
+   */
+static int
+parse_attest (void *cls, json_t *root, struct GNUNET_JSON_Specification *spec)
+{
+  struct GNUNET_RECLAIM_ATTESTATION_Claim *attr;
+  const char *name_str = NULL;
+  const char *val_str = NULL;
+  const char *type_str = NULL;
+  const char *id_str = NULL;
+  char *data;
+  int unpack_state;
+  uint32_t type;
+  size_t data_size;
+
+  GNUNET_assert (NULL != root);
+
+  if (! json_is_object (root))
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Error json is not array nor object!\n");
+    return GNUNET_SYSERR;
+  }
+  // interpret single attribute
+  unpack_state = json_unpack (root,
+                              "{s:s, s?s, s:s, s:s!}",
+                              "name",
+                              &name_str,
+                              "id",
+                              &id_str,
+                              "type",
+                              &type_str,
+                              "value",
+                              &val_str);
+  if ((0 != unpack_state) || (NULL == name_str) || (NULL == val_str) ||
+      (NULL == type_str))
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Error json object has a wrong format!\n");
+    return GNUNET_SYSERR;
+  }
+  type = GNUNET_RECLAIM_ATTESTATION_typename_to_number (type_str);
+  if (GNUNET_SYSERR ==
+      (GNUNET_RECLAIM_ATTESTATION_string_to_value (type,
+                                                   val_str,
+                                                   (void **) &data,
+                                                   &data_size)))
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Attribute value invalid!\n");
+    return GNUNET_SYSERR;
+  }
+  attr = GNUNET_RECLAIM_ATTESTATION_claim_new (name_str, type, data, data_size);
+  if ((NULL == id_str) || (0 == strlen (id_str)))
+    attr->id = 0;
+  else
+    GNUNET_STRINGS_string_to_data (id_str,
+                                   strlen (id_str),
+                                   &attr->id,
+                                   sizeof(uint64_t));
+
+  *(struct GNUNET_RECLAIM_ATTESTATION_Claim **) spec->ptr = attr;
+  return GNUNET_OK;
+}
+
+/**
+ * Cleanup data left from parsing RSA public key.
+ *
+ * @param cls closure, NULL
+ * @param[out] spec where to free the data
+ */
+static void
+clean_attest (void *cls, struct GNUNET_JSON_Specification *spec)
+{
+  struct GNUNET_RECLAIM_ATTESTATION_Claim **attr;
+
+  attr = (struct GNUNET_RECLAIM_ATTESTATION_Claim **) spec->ptr;
+  if (NULL != *attr)
+  {
+    GNUNET_free (*attr);
+    *attr = NULL;
+  }
+}
+/**
+ * JSON Specification for Reclaim attestation claims.
+ *
+ * @param ticket struct of GNUNET_RECLAIM_ATTESTATION_Claim to fill
+ * @return JSON Specification
+ */
+struct GNUNET_JSON_Specification
+GNUNET_RECLAIM_JSON_spec_claim_attest (struct
+                                       GNUNET_RECLAIM_ATTESTATION_Claim **attr)
+{
+  struct GNUNET_JSON_Specification ret = { .parser = &parse_attest,
+                                           .cleaner = &clean_attest,
+                                           .cls = NULL,
+                                           .field = NULL,
+                                           .ptr = attr,
+                                           .ptr_size = 0,
+                                           .size_ptr = NULL };
+
+  *attr = NULL;
+  return ret;
+}
diff --git a/src/reclaim/json_reclaim.h b/src/reclaim/json_reclaim.h
index 3fd26167f..4280cce48 100644
--- a/src/reclaim/json_reclaim.h
+++ b/src/reclaim/json_reclaim.h
@@ -46,3 +46,13 @@ GNUNET_RECLAIM_JSON_spec_claim (struct GNUNET_RECLAIM_ATTRIBUTE_Claim **attr);
  */
 struct GNUNET_JSON_Specification
 GNUNET_RECLAIM_JSON_spec_ticket (struct GNUNET_RECLAIM_Ticket **ticket);
+
+/**
+    * JSON Specification for Reclaim attestation claims.
+    *
+    * @param ticket struct of GNUNET_RECLAIM_ATTESTATION_Claim to fill
+    * @return JSON Specification
+    */
+struct GNUNET_JSON_Specification
+GNUNET_RECLAIM_JSON_spec_claim_attest (struct
+                                       GNUNET_RECLAIM_ATTESTATION_Claim **attr);