1 files changed, 511 insertions, 0 deletions

diff --git a/src/credential/credential_api.c b/src/credential/credential_api.c
new file mode 100644
index 000000000..677cb9ad4
--- /dev/null
+++ b/src/credential/credential_api.c
@@ -0,0 +1,511 @@
+/*
+     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_api.c
+ * @brief library to access the CREDENTIAL service
+ * @author Martin Schanzenbach
+ */
+#include "platform.h"
+#include "gnunet_util_lib.h"
+#include "gnunet_constants.h"
+#include "gnunet_arm_service.h"
+#include "gnunet_hello_lib.h"
+#include "gnunet_protocols.h"
+#include "gnunet_signatures.h"
+#include "credential.h"
+#include "credential_serialization.h"
+#include "gnunet_credential_service.h"
+#include "gnunet_identity_service.h"
+
+
+#define LOG(kind,...) GNUNET_log_from (kind, "credential-api",__VA_ARGS__)
+
+/**
+ * Handle to a verify request
+ */
+struct GNUNET_CREDENTIAL_Request
+{
+
+  /**
+   * DLL
+   */
+  struct GNUNET_CREDENTIAL_Request *next;
+
+  /**
+   * DLL
+   */
+  struct GNUNET_CREDENTIAL_Request *prev;
+
+  /**
+   * handle to credential service
+   */
+  struct GNUNET_CREDENTIAL_Handle *credential_handle;
+
+  /**
+   * processor to call on verify result
+   */
+  GNUNET_CREDENTIAL_CredentialResultProcessor verify_proc;
+
+  /**
+   * @e verify_proc closure
+   */
+  void *proc_cls;
+
+  /**
+   * Envelope with the message for this queue entry.
+   */
+  struct GNUNET_MQ_Envelope *env;
+
+  /**
+   * request id
+   */
+  uint32_t r_id;
+
+};
+
+
+/**
+ * Connection to the CREDENTIAL service.
+ */
+struct GNUNET_CREDENTIAL_Handle
+{
+
+  /**
+   * Configuration to use.
+   */
+  const struct GNUNET_CONFIGURATION_Handle *cfg;
+
+  /**
+   * Connection to service (if available).
+   */
+  struct GNUNET_MQ_Handle *mq;
+
+  /**
+   * Head of linked list of active verify requests.
+   */
+  struct GNUNET_CREDENTIAL_Request *request_head;
+
+  /**
+   * Tail of linked list of active verify requests.
+   */
+  struct GNUNET_CREDENTIAL_Request *request_tail;
+
+  /**
+   * Reconnect task
+   */
+  struct GNUNET_SCHEDULER_Task *reconnect_task;
+
+  /**
+   * How long do we wait until we try to reconnect?
+   */
+  struct GNUNET_TIME_Relative reconnect_backoff;
+
+  /**
+   * Request Id generator.  Incremented by one for each request.
+   */
+  uint32_t r_id_gen;
+
+};
+
+
+/**
+ * Reconnect to CREDENTIAL service.
+ *
+ * @param handle the handle to the CREDENTIAL service
+ */
+static void
+reconnect (struct GNUNET_CREDENTIAL_Handle *handle);
+
+
+/**
+ * Reconnect to CREDENTIAL
+ *
+ * @param cls the handle
+ */
+static void
+reconnect_task (void *cls)
+{
+  struct GNUNET_CREDENTIAL_Handle *handle = cls;
+
+  handle->reconnect_task = NULL;
+  reconnect (handle);
+}
+
+
+/**
+ * Disconnect from service and then reconnect.
+ *
+ * @param handle our handle
+ */
+static void
+force_reconnect (struct GNUNET_CREDENTIAL_Handle *handle)
+{
+  GNUNET_MQ_destroy (handle->mq);
+  handle->mq = NULL;
+  handle->reconnect_backoff
+    = GNUNET_TIME_STD_BACKOFF (handle->reconnect_backoff);
+  handle->reconnect_task
+    = GNUNET_SCHEDULER_add_delayed (handle->reconnect_backoff,
+                        &reconnect_task,
+                        handle);
+}
+
+
+/**
+ * Generic error handler, called with the appropriate error code and
+ * the same closure specified at the creation of the message queue.
+ * Not every message queue implementation supports an error handler.
+ *
+ * @param cls closure with the `struct GNUNET_CREDENTIAL_Handle *`
+ * @param error error code
+ */
+static void
+mq_error_handler (void *cls,
+                  enum GNUNET_MQ_Error error)
+{
+  struct GNUNET_CREDENTIAL_Handle *handle = cls;
+
+  force_reconnect (handle);
+}
+
+/**
+ * Check validity of message received from the CREDENTIAL service
+ *
+ * @param cls the `struct GNUNET_CREDENTIAL_Handle *`
+ * @param vr_msg the incoming message
+ */
+static int
+check_result (void *cls,
+              const struct DelegationChainResultMessage *vr_msg)
+{
+  //TODO
+  return GNUNET_OK;
+}
+
+
+/**
+ * Handler for messages received from the CREDENTIAL service
+ *
+ * @param cls the `struct GNUNET_CREDENTIAL_Handle *`
+ * @param vr_msg the incoming message
+ */
+static void
+handle_result (void *cls,
+               const struct DelegationChainResultMessage *vr_msg)
+{
+  struct GNUNET_CREDENTIAL_Handle *handle = cls;
+  uint32_t r_id = ntohl (vr_msg->id);
+  struct GNUNET_CREDENTIAL_Request *vr;
+  size_t mlen = ntohs (vr_msg->header.size) - sizeof (*vr_msg);
+  uint32_t d_count = ntohl (vr_msg->d_count);
+  uint32_t c_count = ntohl (vr_msg->c_count);
+  struct GNUNET_CREDENTIAL_Delegation d_chain[d_count];
+  struct GNUNET_CREDENTIAL_Credential creds[c_count];
+  GNUNET_CREDENTIAL_CredentialResultProcessor proc;
+  void *proc_cls;
+
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Received verify reply from CREDENTIAL service\n");
+  for (vr = handle->request_head; NULL != vr; vr = vr->next)
+    if (vr->r_id == r_id)
+      break;
+  if (NULL == vr)
+    return;
+  proc = vr->verify_proc;
+  proc_cls = vr->proc_cls;
+  GNUNET_CONTAINER_DLL_remove (handle->request_head,
+                               handle->request_tail,
+                               vr);
+  GNUNET_MQ_discard (vr->env);
+  GNUNET_free (vr);
+  GNUNET_assert (GNUNET_OK ==
+                 GNUNET_CREDENTIAL_delegation_chain_deserialize (mlen,
+                                                                 (const char*) &vr_msg[1],
+                                                                 d_count,
+                                                                 d_chain,
+                                                                 c_count,
+                                                                 creds));
+  if (GNUNET_NO == ntohl (vr_msg->cred_found))
+  {
+    proc (proc_cls,
+          0,
+          NULL,
+          0,
+          NULL); // TODO
+  } else {
+    proc (proc_cls,
+          d_count,
+          d_chain,
+          c_count,
+          creds);
+  }
+}
+
+
+/**
+ * Reconnect to CREDENTIAL service.
+ *
+ * @param handle the handle to the CREDENTIAL service
+ */
+static void
+reconnect (struct GNUNET_CREDENTIAL_Handle *handle)
+{
+  struct GNUNET_MQ_MessageHandler handlers[] = {
+    GNUNET_MQ_hd_var_size (result,
+                           GNUNET_MESSAGE_TYPE_CREDENTIAL_VERIFY_RESULT,
+                           struct DelegationChainResultMessage,
+                           handle),
+    GNUNET_MQ_hd_var_size (result,
+                           GNUNET_MESSAGE_TYPE_CREDENTIAL_COLLECT_RESULT,
+                           struct DelegationChainResultMessage,
+                           handle),
+    GNUNET_MQ_handler_end ()
+  };
+  struct GNUNET_CREDENTIAL_Request *vr;
+
+  GNUNET_assert (NULL == handle->mq);
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Trying to connect to CREDENTIAL\n");
+  handle->mq = GNUNET_CLIENT_connect (handle->cfg,
+                                      "credential",
+                                      handlers,
+                                      &mq_error_handler,
+                                      handle);
+  if (NULL == handle->mq)
+    return;
+  for (vr = handle->request_head; NULL != vr; vr = vr->next)
+    GNUNET_MQ_send_copy (handle->mq,
+                         vr->env);
+}
+
+
+/**
+ * Initialize the connection with the CREDENTIAL service.
+ *
+ * @param cfg configuration to use
+ * @return handle to the CREDENTIAL service, or NULL on error
+ */
+struct GNUNET_CREDENTIAL_Handle *
+GNUNET_CREDENTIAL_connect (const struct GNUNET_CONFIGURATION_Handle *cfg)
+{
+  struct GNUNET_CREDENTIAL_Handle *handle;
+
+  handle = GNUNET_new (struct GNUNET_CREDENTIAL_Handle);
+  handle->cfg = cfg;
+  reconnect (handle);
+  if (NULL == handle->mq)
+  {
+    GNUNET_free (handle);
+    return NULL;
+  }
+  return handle;
+}
+
+
+/**
+ * Shutdown connection with the CREDENTIAL service.
+ *
+ * @param handle handle of the CREDENTIAL connection to stop
+ */
+void
+GNUNET_CREDENTIAL_disconnect (struct GNUNET_CREDENTIAL_Handle *handle)
+{
+  if (NULL != handle->mq)
+  {
+    GNUNET_MQ_destroy (handle->mq);
+    handle->mq = NULL;
+  }
+  if (NULL != handle->reconnect_task)
+  {
+    GNUNET_SCHEDULER_cancel (handle->reconnect_task);
+    handle->reconnect_task = NULL;
+  }
+  GNUNET_assert (NULL == handle->request_head);
+  GNUNET_free (handle);
+}
+
+
+/**
+ * Cancel pending verify request
+ *
+ * @param lr the verify request to cancel
+ */
+void
+GNUNET_CREDENTIAL_request_cancel (struct GNUNET_CREDENTIAL_Request *lr)
+{
+  struct GNUNET_CREDENTIAL_Handle *handle = lr->credential_handle;
+
+  GNUNET_CONTAINER_DLL_remove (handle->request_head,
+                               handle->request_tail,
+                               lr);
+  GNUNET_MQ_discard (lr->env);
+  GNUNET_free (lr);
+}
+
+
+/**
+ * Performs attribute collection.
+ * Collects all credentials of subject to fulfill the 
+ * attribute, if possible
+ *
+ * @param handle handle to the Credential service
+ * @param issuer_key the issuer public key
+ * @param issuer_attribute the issuer attribute
+ * @param subject_key the subject public key
+ * @param proc function to call on result
+ * @param proc_cls closure for processor
+ * @return handle to the queued request
+ */
+struct GNUNET_CREDENTIAL_Request*
+GNUNET_CREDENTIAL_collect (struct GNUNET_CREDENTIAL_Handle *handle,
+                           const struct GNUNET_CRYPTO_EcdsaPublicKey *issuer_key,
+                           const char *issuer_attribute,
+                           const struct GNUNET_CRYPTO_EcdsaPrivateKey *subject_key,
+                           GNUNET_CREDENTIAL_CredentialResultProcessor proc,
+                           void *proc_cls)
+{
+  /* IPC to shorten credential names, return shorten_handle */
+  struct CollectMessage *c_msg;
+  struct GNUNET_CREDENTIAL_Request *vr;
+  size_t nlen;
+
+  if (NULL == issuer_attribute)
+  {
+    GNUNET_break (0);
+    return NULL;
+  }
+
+  //DEBUG LOG
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Trying to collect `%s' in CREDENTIAL\n",
+       issuer_attribute);
+  nlen = strlen (issuer_attribute) + 1;
+  if (nlen >= GNUNET_MAX_MESSAGE_SIZE - sizeof (*vr))
+  {
+    GNUNET_break (0);
+    return NULL;
+  }
+  vr = GNUNET_new (struct GNUNET_CREDENTIAL_Request);
+  vr->credential_handle = handle;
+  vr->verify_proc = proc;
+  vr->proc_cls = proc_cls;
+  vr->r_id = handle->r_id_gen++;
+  vr->env = GNUNET_MQ_msg_extra (c_msg,
+                                 nlen,
+                                 GNUNET_MESSAGE_TYPE_CREDENTIAL_COLLECT);
+  c_msg->id = htonl (vr->r_id);
+  c_msg->subject_key = *subject_key;
+  c_msg->issuer_key =  *issuer_key;
+  c_msg->issuer_attribute_len = htons(strlen(issuer_attribute));
+  GNUNET_memcpy (&c_msg[1],
+                 issuer_attribute,
+                 strlen (issuer_attribute));
+  GNUNET_CONTAINER_DLL_insert (handle->request_head,
+                               handle->request_tail,
+                               vr);
+  if (NULL != handle->mq)
+    GNUNET_MQ_send_copy (handle->mq,
+                         vr->env);
+  return vr;
+}
+/**
+ * Performs attribute verification.
+ * Checks if there is a delegation chain from
+ * attribute ``issuer_attribute'' issued by the issuer
+ * with public key ``issuer_key'' maps to the attribute
+ * ``subject_attribute'' claimed by the subject with key
+ * ``subject_key''
+ *
+ * @param handle handle to the Credential service
+ * @param issuer_key the issuer public key
+ * @param issuer_attribute the issuer attribute
+ * @param subject_key the subject public key
+ * @param credential_count number of credentials provided
+ * @param credentials subject credentials
+ * @param proc function to call on result
+ * @param proc_cls closure for processor
+ * @return handle to the queued request
+ */
+struct GNUNET_CREDENTIAL_Request*
+GNUNET_CREDENTIAL_verify (struct GNUNET_CREDENTIAL_Handle *handle,
+                          const struct GNUNET_CRYPTO_EcdsaPublicKey *issuer_key,
+                          const char *issuer_attribute,
+                          const struct GNUNET_CRYPTO_EcdsaPublicKey *subject_key,
+                          uint32_t credential_count,
+                          const struct GNUNET_CREDENTIAL_Credential *credentials,
+                          GNUNET_CREDENTIAL_CredentialResultProcessor proc,
+                          void *proc_cls)
+{
+  /* IPC to shorten credential names, return shorten_handle */
+  struct VerifyMessage *v_msg;
+  struct GNUNET_CREDENTIAL_Request *vr;
+  size_t nlen;
+  size_t clen;
+
+  if (NULL == issuer_attribute || NULL == credentials)
+  {
+    GNUNET_break (0);
+    return NULL;
+  }
+
+  clen = GNUNET_CREDENTIAL_credentials_get_size (credential_count,
+                                                 credentials);
+
+  //DEBUG LOG
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Trying to verify `%s' in CREDENTIAL\n",
+       issuer_attribute);
+  nlen = strlen (issuer_attribute) + 1 + clen;
+  if (nlen >= GNUNET_MAX_MESSAGE_SIZE - sizeof (*vr))
+  {
+    GNUNET_break (0);
+    return NULL;
+  }
+  vr = GNUNET_new (struct GNUNET_CREDENTIAL_Request);
+  vr->credential_handle = handle;
+  vr->verify_proc = proc;
+  vr->proc_cls = proc_cls;
+  vr->r_id = handle->r_id_gen++;
+  vr->env = GNUNET_MQ_msg_extra (v_msg,
+                                 nlen,
+                                 GNUNET_MESSAGE_TYPE_CREDENTIAL_VERIFY);
+  v_msg->id = htonl (vr->r_id);
+  v_msg->subject_key = *subject_key;
+  v_msg->c_count = htonl(credential_count);
+  v_msg->issuer_key =  *issuer_key;
+  v_msg->issuer_attribute_len = htons(strlen(issuer_attribute));
+  GNUNET_memcpy (&v_msg[1],
+                 issuer_attribute,
+                 strlen (issuer_attribute));
+  GNUNET_CREDENTIAL_credentials_serialize (credential_count,
+                                           credentials,
+                                           clen,
+                                           ((char*)&v_msg[1])
+                                           + strlen (issuer_attribute) + 1);
+  GNUNET_CONTAINER_DLL_insert (handle->request_head,
+                               handle->request_tail,
+                               vr);
+  if (NULL != handle->mq)
+    GNUNET_MQ_send_copy (handle->mq,
+                         vr->env);
+  return vr;
+}
+
+/* end of credential_api.c */