-move shorten logic to its own file

5 files changed, 641 insertions, 536 deletions

diff --git a/src/gns/Makefile.am b/src/gns/Makefile.am
index 10177996e..c2e4264b5 100644
--- a/src/gns/Makefile.am
+++ b/src/gns/Makefile.am
@@ -129,6 +129,7 @@ w32nsp_resolve_LDADD = -lws2_32
 gnunet_service_gns_SOURCES = \
  gnunet-service-gns.c \
  gnunet-service-gns_resolver.c gnunet-service-gns_resolver.h \
+ gnunet-service-gns_shorten.c gnunet-service-gns_shorten.h \
  gnunet-service-gns_interceptor.c gnunet-service-gns_interceptor.h 
 gnunet_service_gns_LDADD = \
   -lm \
diff --git a/src/gns/gnunet-service-gns.c b/src/gns/gnunet-service-gns.c
index 583a5131a..b21584350 100644
--- a/src/gns/gnunet-service-gns.c
+++ b/src/gns/gnunet-service-gns.c
@@ -34,6 +34,7 @@
 #include "gnunet_statistics_service.h"
 #include "gns.h"
 #include "gnunet-service-gns_resolver.h"
+#include "gnunet-service-gns_shorten.h"
 #include "gnunet-service-gns_interceptor.h"
 #include "gnunet_protocols.h"
 
@@ -214,6 +215,7 @@ shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 
   GNS_interceptor_done ();
   GNS_resolver_done ();
+  GNS_shorten_done ();
   if (NULL != statistics)
   {
     GNUNET_STATISTICS_destroy (statistics, GNUNET_NO);
@@ -718,11 +720,10 @@ run (void *cls, struct GNUNET_SERVER_Handle *server,
       return;
     }
   }
-  /* FIXME: install client disconnect handle to clean up pending
-     lookups on client disconnect! */
   GNS_resolver_init (namestore_handle, dht_handle, 
                      c,
                      max_parallel_bg_queries);
+  GNS_shorten_init (namestore_handle, dht_handle);
   GNUNET_SERVER_disconnect_notify (server,
                                    &notify_client_disconnect,
                                    NULL);
diff --git a/src/gns/gnunet-service-gns_resolver.c b/src/gns/gnunet-service-gns_resolver.c
index b131a4750..0fb6ffbd1 100644
--- a/src/gns/gnunet-service-gns_resolver.c
+++ b/src/gns/gnunet-service-gns_resolver.c
@@ -53,7 +53,6 @@
  */
 #include "platform.h"
 #include "gnunet_util_lib.h"
-#include "gnunet_transport_service.h"
 #include "gnunet_dnsstub_lib.h"
 #include "gnunet_dht_service.h"
 #include "gnunet_namestore_service.h"
@@ -63,6 +62,7 @@
 #include "gnunet_gns_service.h"
 #include "gns.h"
 #include "gnunet-service-gns_resolver.h"
+#include "gnunet-service-gns_shorten.h"
 #include "gnunet_vpn_service.h"
 
 
@@ -159,53 +159,6 @@ struct AuthorityChain
 
 
 /**
- * Resolution status indicator
- */
-enum ResolutionStatus
-{
-  /**
-   * the name to lookup exists
-   */
-  RSL_RECORD_EXISTS = 1,
-
-  /**
-   * the name in the record expired
-   */
-  RSL_RECORD_EXPIRED = 2,
- 
-  /**
-   * resolution timed out
-   */
-  RSL_TIMED_OUT = 4,
- 
-  /**
-   * Found VPN delegation
-   */
-  RSL_DELEGATE_VPN = 8,
- 
-  /**
-   * Found NS delegation
-   */
-  RSL_DELEGATE_NS = 16,
- 
-  /**
-   * Found PKEY delegation
-   */
-  RSL_DELEGATE_PKEY = 32,
-  
-  /**
-   * Found CNAME record
-   */
-  RSL_CNAME_FOUND = 64,
-  
-  /**
-   * Found PKEY has been revoked
-   */
-  RSL_PKEY_REVOKED = 128
-};
-
-
-/**
  * A result we got from DNS.
  */
 struct DnsResult
@@ -402,60 +355,6 @@ struct GNS_ResolverHandle
 
 
 /**
- * Handle for a PSEU lookup used to shorten names.
- */
-struct GetPseuAuthorityHandle
-{
-  /**
-   * DLL
-   */
-  struct GetPseuAuthorityHandle *next;
-
-  /**
-   * DLL
-   */
-  struct GetPseuAuthorityHandle *prev;
-
-  /**
-   * Private key of the (shorten) zone to store the resulting
-   * pseudonym in.
-   */
-  struct GNUNET_CRYPTO_EccPrivateKey shorten_zone_key;
-
-  /**
-   * Original label (used if no PSEU record is found).
-   */
-  char label[GNUNET_DNSPARSER_MAX_LABEL_LENGTH + 1];
-
-  /**
-   * Label we are currently trying out (during #perform_pseu_lookup).
-   */
-  char *current_label;
-
-  /**
-   * The zone for which we are trying to find the PSEU record.
-   */
-  struct GNUNET_CRYPTO_EccPublicKey target_zone;
-
-  /**
-   * Handle for DHT lookups. Should be NULL if no lookups are in progress 
-   */
-  struct GNUNET_DHT_GetHandle *get_handle;
-
-  /**
-   * Handle to namestore request 
-   */
-  struct GNUNET_NAMESTORE_QueueEntry *namestore_task;
-
-  /**
-   * Task to abort DHT lookup operation.
-   */
-  GNUNET_SCHEDULER_TaskIdentifier timeout_task;
-
-};
-
-
-/**
  * Our handle to the namestore service
  */
 static struct GNUNET_NAMESTORE_Handle *namestore_handle;
@@ -486,16 +385,6 @@ static struct GNUNET_CONTAINER_Heap *dht_lookup_heap;
 static unsigned long long max_allowed_background_queries;
 
 /**
- * Head of PSEU/shorten operations list.
- */
-struct GetPseuAuthorityHandle *gph_head;
-
-/**
- * Tail of PSEU/shorten operations list.
- */
-struct GetPseuAuthorityHandle *gph_tail;
-
-/**
  * Head of resolver lookup list
  */
 static struct GNS_ResolverHandle *rlh_head;
@@ -576,425 +465,6 @@ is_canonical (const char *name)
 }
 
 
-/* ******************** Shortening logic ************************ */
-
-
-/**
- * Cleanup a 'struct GetPseuAuthorityHandle', terminating all
- * pending activities.
- *
- * @param gph handle to terminate
- */
-static void
-free_get_pseu_authority_handle (struct GetPseuAuthorityHandle *gph)
-{
-  if (NULL != gph->get_handle)
-  {
-    GNUNET_DHT_get_stop (gph->get_handle);
-    gph->get_handle = NULL;
-  }
-  if (NULL != gph->namestore_task)
-  {
-    GNUNET_NAMESTORE_cancel (gph->namestore_task);
-    gph->namestore_task = NULL;
-  }
-  if (GNUNET_SCHEDULER_NO_TASK != gph->timeout_task)
-  {
-    GNUNET_SCHEDULER_cancel (gph->timeout_task);
-    gph->timeout_task = GNUNET_SCHEDULER_NO_TASK;
-  }
-  GNUNET_CONTAINER_DLL_remove (gph_head, gph_tail, gph);
-  GNUNET_free_non_null (gph->current_label);
-  GNUNET_free (gph);
-}
-
-
-/**
- * Continuation for pkey record creation (shorten)
- *
- * @param cls a GetPseuAuthorityHandle
- * @param success unused
- * @param emsg unused
- */
-static void
-create_pkey_cont (void* cls, 
-                  int32_t success, 
-                  const char *emsg)
-{
-  struct GetPseuAuthorityHandle* gph = cls;
-
-  gph->namestore_task = NULL;
-  free_get_pseu_authority_handle (gph);
-}
-
-
-/**
- * Namestore calls this function if we have record for this name.
- * (or with rd_count=0 to indicate no matches).
- *
- * @param cls the pending query
- * @param rd_count the number of records with 'name'
- * @param rd the record data
- */
-static void
-process_pseu_lookup_ns (void *cls,
-                        unsigned int rd_count,
-                        const struct GNUNET_NAMESTORE_RecordData *rd);
-
-
-/**
- * We obtained a result for our query to the shorten zone from
- * the namestore.  Try to decrypt.
- *
- * @param cls the handle to our shorten operation
- * @param block resulting encrypted block
- */
-static void
-process_pseu_block_ns (void *cls,
-                       const struct GNUNET_NAMESTORE_Block *block)
-{
-  struct GetPseuAuthorityHandle *gph = cls;
-  struct GNUNET_CRYPTO_EccPublicKey pub;
-
-  gph->namestore_task = NULL;
-  if (NULL == block)
-  {
-    process_pseu_lookup_ns (gph, 0, NULL);
-    return;
-  }
-  GNUNET_CRYPTO_ecc_key_get_public (&gph->shorten_zone_key,
-                                    &pub);
-  if (GNUNET_OK != 
-      GNUNET_NAMESTORE_block_decrypt (block,
-                                      &pub,
-                                      gph->current_label,
-                                      &process_pseu_lookup_ns,
-                                      gph))
-  {
-    GNUNET_break (0);
-    free_get_pseu_authority_handle (gph);
-    return;
-  }
-}
-
-
-/**
- * Lookup in the namestore for the shorten zone the given label.
- *
- * @param gph the handle to our shorten operation
- * @param label the label to lookup
- */
-static void 
-perform_pseu_lookup (struct GetPseuAuthorityHandle *gph,
-                     const char *label)
-{ 
-  struct GNUNET_CRYPTO_EccPublicKey pub;
-  struct GNUNET_HashCode query;
-
-  GNUNET_CRYPTO_ecc_key_get_public (&gph->shorten_zone_key,
-                                    &pub);
-  GNUNET_free_non_null (gph->current_label);
-  gph->current_label = GNUNET_strdup (label);
-  GNUNET_NAMESTORE_query_from_public_key (&pub,
-                                          label,
-                                          &query);
-  gph->namestore_task = GNUNET_NAMESTORE_lookup_block (namestore_handle,
-                                                       &query,
-                                                       &process_pseu_block_ns,
-                                                       gph);
-}
-
-
-/**
- * Namestore calls this function if we have record for this name.
- * (or with rd_count=0 to indicate no matches).
- *
- * @param cls the pending query
- * @param rd_count the number of records with 'name'
- * @param rd the record data
- */
-static void
-process_pseu_lookup_ns (void *cls,
-                        unsigned int rd_count,
-                        const struct GNUNET_NAMESTORE_RecordData *rd)
-{
-  struct GetPseuAuthorityHandle *gph = cls;
-  struct GNUNET_NAMESTORE_RecordData new_pkey;
-
-  gph->namestore_task = NULL;
-  if (rd_count > 0)
-  {
-    GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
-               "Name `%s' already taken, cannot shorten.\n", 
-               gph->current_label);
-    /* if this was not yet the original label, try one more
-       time, this time not using PSEU but the original label */
-    if (0 == strcmp (gph->current_label,
-                     gph->label))
-    {
-      free_get_pseu_authority_handle (gph);
-    }
-    else
-    {
-      perform_pseu_lookup (gph, gph->label);
-    }
-    return;
-  }
-  /* name is available */
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "Shortening `%s' to `%s'\n", 
-              GNUNET_NAMESTORE_z2s (&gph->target_zone),
-              gph->current_label);
-  new_pkey.expiration_time = UINT64_MAX;
-  new_pkey.data_size = sizeof (struct GNUNET_CRYPTO_EccPublicKey);
-  new_pkey.data = &gph->target_zone;
-  new_pkey.record_type = GNUNET_NAMESTORE_TYPE_PKEY;
-  new_pkey.flags = GNUNET_NAMESTORE_RF_AUTHORITY
-                 | GNUNET_NAMESTORE_RF_PRIVATE
-                 | GNUNET_NAMESTORE_RF_PENDING;
-  gph->namestore_task 
-    = GNUNET_NAMESTORE_records_store (namestore_handle,
-                                      &gph->shorten_zone_key,
-                                      gph->current_label,
-                                      1, &new_pkey,
-                                      &create_pkey_cont, gph);
-}
-
-
-/**
- * Process result of a DHT lookup for a PSEU record.
- *
- * @param gph the handle to our shorten operation
- * @param pseu the pseu result or NULL
- */
-static void
-process_pseu_result (struct GetPseuAuthorityHandle* gph, 
-                     const char *pseu)
-{
-  if (NULL == pseu)
-  {
-    /* no PSEU found, try original label */
-    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                "No PSEU found, trying original label `%s' instead.\n",
-                gph->label);
-    perform_pseu_lookup (gph, gph->label);
-    return;
-  }  
-  /* check if 'pseu' is taken */
-  perform_pseu_lookup (gph, pseu);
-}
-
-
-/**
- * Handle timeout for DHT request during shortening.
- *
- * @param cls the request handle as closure
- * @param tc the task context
- */
-static void
-handle_auth_discovery_timeout (void *cls,
-                               const struct GNUNET_SCHEDULER_TaskContext *tc)
-{
-  struct GetPseuAuthorityHandle *gph = cls;
-
-  gph->timeout_task = GNUNET_SCHEDULER_NO_TASK;
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "DHT lookup for PSEU query timed out.\n");
-  GNUNET_DHT_get_stop (gph->get_handle);
-  gph->get_handle = NULL;
-  process_pseu_result (gph, NULL);
-}
-
-
-/**
- * Handle decrypted records from DHT result.
- *
- * @param cls closure with our 'struct GetPseuAuthorityHandle'
- * @param rd_count number of entries in 'rd' array
- * @param rd array of records with data to store
- */
-static void
-process_auth_records (void *cls,
-                      unsigned int rd_count,
-                      const struct GNUNET_NAMESTORE_RecordData *rd)
-{
-  struct GetPseuAuthorityHandle *gph = cls;
-  unsigned int i;
-
-  for (i=0; i < rd_count; i++)
-  {
-    if (GNUNET_NAMESTORE_TYPE_PSEU == rd[i].record_type)
-    {
-      /* found pseu */
-      process_pseu_result (gph, 
-                           (const char *) rd[i].data);
-      return;
-    }
-  }
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "No PSEU record found in DHT reply.\n");
-  process_pseu_result (gph, NULL);
-}
-
-
-/**
- * Function called when we find a PSEU entry in the DHT
- *
- * @param cls the request handle
- * @param exp lifetime
- * @param key the key the record was stored under
- * @param get_path get path
- * @param get_path_length get path length
- * @param put_path put path
- * @param put_path_length put path length
- * @param type the block type
- * @param size the size of the record
- * @param data the record data
- */
-static void
-process_auth_discovery_dht_result (void* cls,
-                                   struct GNUNET_TIME_Absolute exp,
-                                   const struct GNUNET_HashCode *key,
-                                   const struct GNUNET_PeerIdentity *get_path,
-                                   unsigned int get_path_length,
-                                   const struct GNUNET_PeerIdentity *put_path,
-                                   unsigned int put_path_length,
-                                   enum GNUNET_BLOCK_Type type,
-                                   size_t size,
-                                   const void *data)
-{
-  struct GetPseuAuthorityHandle *gph = cls;
-  const struct GNUNET_NAMESTORE_Block *block;
-
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "Got DHT result for PSEU request\n");
-  GNUNET_DHT_get_stop (gph->get_handle);
-  gph->get_handle = NULL;
-  GNUNET_SCHEDULER_cancel (gph->timeout_task);
-  gph->timeout_task = GNUNET_SCHEDULER_NO_TASK;
-
-  if (NULL == data)
-  {
-    /* is this allowed!? */
-    GNUNET_break (0);
-    process_pseu_result (gph, NULL);
-    return;
-  }
-  if (size < sizeof (struct GNUNET_NAMESTORE_Block))
-  {
-    /* how did this pass DHT block validation!? */
-    GNUNET_break (0);
-    process_pseu_result (gph, NULL);
-    return;   
-  }
-  block = data;
-  if (size !=
-      ntohs (block->purpose.size) + 
-      sizeof (struct GNUNET_CRYPTO_EccPublicKey) +
-      sizeof (struct GNUNET_CRYPTO_EccSignature))
-  {
-    /* how did this pass DHT block validation!? */
-    GNUNET_break (0);
-    process_pseu_result (gph, NULL);
-    return;   
-  }
-  if (GNUNET_OK !=
-      GNUNET_NAMESTORE_block_decrypt (block,
-                                      &gph->target_zone,
-                                      GNUNET_GNS_TLD_PLUS,
-                                      &process_auth_records,
-                                      gph))
-  {
-    /* other peer encrypted invalid block, complain */
-    GNUNET_break_op (0);
-    process_pseu_result (gph, NULL);
-    return;   
-  }
-}
-
-
-/**
- * Callback called by namestore for a zone to name result.  We're
- * trying to see if a short name for a given zone already exists.
- *
- * @param cls the closure
- * @param zone_key the zone we queried
- * @param name the name found or NULL
- * @param rd_len number of records for the name
- * @param rd the record data (PKEY) for the name
- */
-static void
-process_zone_to_name_discover (void *cls,
-                               const struct GNUNET_CRYPTO_EccPrivateKey *zone_key,
-                               const char *name,
-                               unsigned int rd_len,
-                               const struct GNUNET_NAMESTORE_RecordData *rd)
-{
-  struct GetPseuAuthorityHandle* gph = cls;
-  struct GNUNET_HashCode lookup_key;
-  
-  gph->namestore_task = NULL;
-  if (0 != rd_len)
-  {
-    /* we found a match in our own zone */
-    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                "Shortening aborted, name `%s' already reserved for the zone\n",
-                name);
-    free_get_pseu_authority_handle (gph);
-    return;
-  }
-  /* record does not yet exist, go into DHT to find PSEU record */
-  GNUNET_NAMESTORE_query_from_public_key (&gph->target_zone,
-                                          GNUNET_GNS_TLD_PLUS,                                    
-                                          &lookup_key);
-  gph->timeout_task = GNUNET_SCHEDULER_add_delayed (DHT_LOOKUP_TIMEOUT,
-                                                    &handle_auth_discovery_timeout, 
-                                                    gph);
-  gph->get_handle = GNUNET_DHT_get_start (dht_handle,
-                                          GNUNET_BLOCK_TYPE_GNS_NAMERECORD,
-                                          &lookup_key,
-                                          DHT_GNS_REPLICATION_LEVEL,
-                                          GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE,
-                                          NULL, 0,
-                                          &process_auth_discovery_dht_result,
-                                          gph);
-}
-
-
-/**
- * Start shortening algorithm, try to allocate a nice short
- * canonical name for @a pub in @a shorten_zone, using
- * @a original_label as one possible suggestion.
- *
- * @param original_label original label for the zone
- * @param pub public key of the zone to shorten
- * @param shorten_zone private key of the target zone for the new record
- */
-static void
-start_shorten (const char *original_label,
-               const struct GNUNET_CRYPTO_EccPublicKey *pub,
-               const struct GNUNET_CRYPTO_EccPrivateKey *shorten_zone)
-{
-  struct GetPseuAuthorityHandle *gph;
-  
-  if (strlen (original_label) > GNUNET_DNSPARSER_MAX_LABEL_LENGTH)
-  {
-    GNUNET_break (0);
-    return;
-  }
-  gph = GNUNET_new (struct GetPseuAuthorityHandle);
-  gph->shorten_zone_key = *shorten_zone;
-  gph->target_zone = *pub;
-  strcpy (gph->label, original_label);
-  GNUNET_CONTAINER_DLL_insert (gph_head, gph_tail, gph);
-  /* first, check if we *already* have a record for this zone */
-  gph->namestore_task = GNUNET_NAMESTORE_zone_to_name (namestore_handle,
-                                                       shorten_zone,
-                                                       pub,
-                                                       &process_zone_to_name_discover,
-                                                       gph);
-}
-
 
 /* ************************** Resolution **************************** */
 
@@ -2394,15 +1864,14 @@ GNS_resolver_done ()
     rh->proc (rh->proc_cls, 0, NULL);
     GNS_resolver_lookup_cancel (rh);    
   }
-  /* abort active shorten operations */
-  while (NULL != gph_head)
-    free_get_pseu_authority_handle (gph_head);
   GNUNET_CONTAINER_heap_destroy (dht_lookup_heap);
   dht_lookup_heap = NULL;
   GNUNET_DNSSTUB_stop (dns_handle);
   dns_handle = NULL;
   GNUNET_VPN_disconnect (vpn_handle);
   vpn_handle = NULL;
+  dht_handle = NULL;
+  namestore_handle = NULL;
 }
 
 
diff --git a/src/gns/gnunet-service-gns_shorten.c b/src/gns/gnunet-service-gns_shorten.c
new file mode 100644
index 000000000..6f27a7234
--- /dev/null
+++ b/src/gns/gnunet-service-gns_shorten.c
@@ -0,0 +1,568 @@
+/*
+     This file is part of GNUnet.
+     (C) 2011-2013 Christian Grothoff (and other contributing authors)
+
+     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., 59 Temple Place - Suite 330,
+     Boston, MA 02111-1307, USA.
+*/
+
+/**
+ * @file gns/gnunet-service-gns_shorten.c
+ * @brief GNUnet GNS shortening logic
+ * @author Martin Schanzenbach
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "gnunet_util_lib.h"
+#include "gnunet_dht_service.h"
+#include "gnunet_namestore_service.h"
+#include "gnunet_resolver_service.h"
+#include "gnunet_gns_service.h"
+#include "gns.h"
+#include "gnunet-service-gns_shorten.h"
+#include "gnunet_vpn_service.h"
+
+
+/**
+ * Default DHT timeout for lookups.
+ */
+#define DHT_LOOKUP_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 60)
+
+/**
+ * DHT replication level
+ */
+#define DHT_GNS_REPLICATION_LEVEL 5
+
+
+/**
+ * Handle for a PSEU lookup used to shorten names.
+ */
+struct GetPseuAuthorityHandle
+{
+  /**
+   * DLL
+   */
+  struct GetPseuAuthorityHandle *next;
+
+  /**
+   * DLL
+   */
+  struct GetPseuAuthorityHandle *prev;
+
+  /**
+   * Private key of the (shorten) zone to store the resulting
+   * pseudonym in.
+   */
+  struct GNUNET_CRYPTO_EccPrivateKey shorten_zone_key;
+
+  /**
+   * Original label (used if no PSEU record is found).
+   */
+  char label[GNUNET_DNSPARSER_MAX_LABEL_LENGTH + 1];
+
+  /**
+   * Label we are currently trying out (during #perform_pseu_lookup).
+   */
+  char *current_label;
+
+  /**
+   * The zone for which we are trying to find the PSEU record.
+   */
+  struct GNUNET_CRYPTO_EccPublicKey target_zone;
+
+  /**
+   * Handle for DHT lookups. Should be NULL if no lookups are in progress 
+   */
+  struct GNUNET_DHT_GetHandle *get_handle;
+
+  /**
+   * Handle to namestore request 
+   */
+  struct GNUNET_NAMESTORE_QueueEntry *namestore_task;
+
+  /**
+   * Task to abort DHT lookup operation.
+   */
+  GNUNET_SCHEDULER_TaskIdentifier timeout_task;
+
+};
+
+
+/**
+ * Head of PSEU/shorten operations list.
+ */
+static struct GetPseuAuthorityHandle *gph_head;
+
+/**
+ * Tail of PSEU/shorten operations list.
+ */
+static struct GetPseuAuthorityHandle *gph_tail;
+
+/**
+ * Our handle to the namestore service
+ */
+static struct GNUNET_NAMESTORE_Handle *namestore_handle;
+
+/**
+ * Resolver handle to the dht
+ */
+static struct GNUNET_DHT_Handle *dht_handle;
+
+/**
+ * Cleanup a 'struct GetPseuAuthorityHandle', terminating all
+ * pending activities.
+ *
+ * @param gph handle to terminate
+ */
+static void
+free_get_pseu_authority_handle (struct GetPseuAuthorityHandle *gph)
+{
+  if (NULL != gph->get_handle)
+  {
+    GNUNET_DHT_get_stop (gph->get_handle);
+    gph->get_handle = NULL;
+  }
+  if (NULL != gph->namestore_task)
+  {
+    GNUNET_NAMESTORE_cancel (gph->namestore_task);
+    gph->namestore_task = NULL;
+  }
+  if (GNUNET_SCHEDULER_NO_TASK != gph->timeout_task)
+  {
+    GNUNET_SCHEDULER_cancel (gph->timeout_task);
+    gph->timeout_task = GNUNET_SCHEDULER_NO_TASK;
+  }
+  GNUNET_CONTAINER_DLL_remove (gph_head, gph_tail, gph);
+  GNUNET_free_non_null (gph->current_label);
+  GNUNET_free (gph);
+}
+
+
+/**
+ * Continuation for pkey record creation (shorten)
+ *
+ * @param cls a GetPseuAuthorityHandle
+ * @param success unused
+ * @param emsg unused
+ */
+static void
+create_pkey_cont (void* cls, 
+                  int32_t success, 
+                  const char *emsg)
+{
+  struct GetPseuAuthorityHandle* gph = cls;
+
+  gph->namestore_task = NULL;
+  free_get_pseu_authority_handle (gph);
+}
+
+
+/**
+ * Namestore calls this function if we have record for this name.
+ * (or with rd_count=0 to indicate no matches).
+ *
+ * @param cls the pending query
+ * @param rd_count the number of records with 'name'
+ * @param rd the record data
+ */
+static void
+process_pseu_lookup_ns (void *cls,
+                        unsigned int rd_count,
+                        const struct GNUNET_NAMESTORE_RecordData *rd);
+
+
+/**
+ * We obtained a result for our query to the shorten zone from
+ * the namestore.  Try to decrypt.
+ *
+ * @param cls the handle to our shorten operation
+ * @param block resulting encrypted block
+ */
+static void
+process_pseu_block_ns (void *cls,
+                       const struct GNUNET_NAMESTORE_Block *block)
+{
+  struct GetPseuAuthorityHandle *gph = cls;
+  struct GNUNET_CRYPTO_EccPublicKey pub;
+
+  gph->namestore_task = NULL;
+  if (NULL == block)
+  {
+    process_pseu_lookup_ns (gph, 0, NULL);
+    return;
+  }
+  GNUNET_CRYPTO_ecc_key_get_public (&gph->shorten_zone_key,
+                                    &pub);
+  if (GNUNET_OK != 
+      GNUNET_NAMESTORE_block_decrypt (block,
+                                      &pub,
+                                      gph->current_label,
+                                      &process_pseu_lookup_ns,
+                                      gph))
+  {
+    GNUNET_break (0);
+    free_get_pseu_authority_handle (gph);
+    return;
+  }
+}
+
+
+/**
+ * Lookup in the namestore for the shorten zone the given label.
+ *
+ * @param gph the handle to our shorten operation
+ * @param label the label to lookup
+ */
+static void 
+perform_pseu_lookup (struct GetPseuAuthorityHandle *gph,
+                     const char *label)
+{ 
+  struct GNUNET_CRYPTO_EccPublicKey pub;
+  struct GNUNET_HashCode query;
+
+  GNUNET_CRYPTO_ecc_key_get_public (&gph->shorten_zone_key,
+                                    &pub);
+  GNUNET_free_non_null (gph->current_label);
+  gph->current_label = GNUNET_strdup (label);
+  GNUNET_NAMESTORE_query_from_public_key (&pub,
+                                          label,
+                                          &query);
+  gph->namestore_task = GNUNET_NAMESTORE_lookup_block (namestore_handle,
+                                                       &query,
+                                                       &process_pseu_block_ns,
+                                                       gph);
+}
+
+
+/**
+ * Namestore calls this function if we have record for this name.
+ * (or with rd_count=0 to indicate no matches).
+ *
+ * @param cls the pending query
+ * @param rd_count the number of records with 'name'
+ * @param rd the record data
+ */
+static void
+process_pseu_lookup_ns (void *cls,
+                        unsigned int rd_count,
+                        const struct GNUNET_NAMESTORE_RecordData *rd)
+{
+  struct GetPseuAuthorityHandle *gph = cls;
+  struct GNUNET_NAMESTORE_RecordData new_pkey;
+
+  gph->namestore_task = NULL;
+  if (rd_count > 0)
+  {
+    GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
+               "Name `%s' already taken, cannot shorten.\n", 
+               gph->current_label);
+    /* if this was not yet the original label, try one more
+       time, this time not using PSEU but the original label */
+    if (0 == strcmp (gph->current_label,
+                     gph->label))
+    {
+      free_get_pseu_authority_handle (gph);
+    }
+    else
+    {
+      perform_pseu_lookup (gph, gph->label);
+    }
+    return;
+  }
+  /* name is available */
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Shortening `%s' to `%s'\n", 
+              GNUNET_NAMESTORE_z2s (&gph->target_zone),
+              gph->current_label);
+  new_pkey.expiration_time = UINT64_MAX;
+  new_pkey.data_size = sizeof (struct GNUNET_CRYPTO_EccPublicKey);
+  new_pkey.data = &gph->target_zone;
+  new_pkey.record_type = GNUNET_NAMESTORE_TYPE_PKEY;
+  new_pkey.flags = GNUNET_NAMESTORE_RF_AUTHORITY
+                 | GNUNET_NAMESTORE_RF_PRIVATE
+                 | GNUNET_NAMESTORE_RF_PENDING;
+  gph->namestore_task 
+    = GNUNET_NAMESTORE_records_store (namestore_handle,
+                                      &gph->shorten_zone_key,
+                                      gph->current_label,
+                                      1, &new_pkey,
+                                      &create_pkey_cont, gph);
+}
+
+
+/**
+ * Process result of a DHT lookup for a PSEU record.
+ *
+ * @param gph the handle to our shorten operation
+ * @param pseu the pseu result or NULL
+ */
+static void
+process_pseu_result (struct GetPseuAuthorityHandle* gph, 
+                     const char *pseu)
+{
+  if (NULL == pseu)
+  {
+    /* no PSEU found, try original label */
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                "No PSEU found, trying original label `%s' instead.\n",
+                gph->label);
+    perform_pseu_lookup (gph, gph->label);
+    return;
+  }  
+  /* check if 'pseu' is taken */
+  perform_pseu_lookup (gph, pseu);
+}
+
+
+/**
+ * Handle timeout for DHT request during shortening.
+ *
+ * @param cls the request handle as closure
+ * @param tc the task context
+ */
+static void
+handle_auth_discovery_timeout (void *cls,
+                               const struct GNUNET_SCHEDULER_TaskContext *tc)
+{
+  struct GetPseuAuthorityHandle *gph = cls;
+
+  gph->timeout_task = GNUNET_SCHEDULER_NO_TASK;
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "DHT lookup for PSEU query timed out.\n");
+  GNUNET_DHT_get_stop (gph->get_handle);
+  gph->get_handle = NULL;
+  process_pseu_result (gph, NULL);
+}
+
+
+/**
+ * Handle decrypted records from DHT result.
+ *
+ * @param cls closure with our 'struct GetPseuAuthorityHandle'
+ * @param rd_count number of entries in 'rd' array
+ * @param rd array of records with data to store
+ */
+static void
+process_auth_records (void *cls,
+                      unsigned int rd_count,
+                      const struct GNUNET_NAMESTORE_RecordData *rd)
+{
+  struct GetPseuAuthorityHandle *gph = cls;
+  unsigned int i;
+
+  for (i=0; i < rd_count; i++)
+  {
+    if (GNUNET_NAMESTORE_TYPE_PSEU == rd[i].record_type)
+    {
+      /* found pseu */
+      process_pseu_result (gph, 
+                           (const char *) rd[i].data);
+      return;
+    }
+  }
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "No PSEU record found in DHT reply.\n");
+  process_pseu_result (gph, NULL);
+}
+
+
+/**
+ * Function called when we find a PSEU entry in the DHT
+ *
+ * @param cls the request handle
+ * @param exp lifetime
+ * @param key the key the record was stored under
+ * @param get_path get path
+ * @param get_path_length get path length
+ * @param put_path put path
+ * @param put_path_length put path length
+ * @param type the block type
+ * @param size the size of the record
+ * @param data the record data
+ */
+static void
+process_auth_discovery_dht_result (void* cls,
+                                   struct GNUNET_TIME_Absolute exp,
+                                   const struct GNUNET_HashCode *key,
+                                   const struct GNUNET_PeerIdentity *get_path,
+                                   unsigned int get_path_length,
+                                   const struct GNUNET_PeerIdentity *put_path,
+                                   unsigned int put_path_length,
+                                   enum GNUNET_BLOCK_Type type,
+                                   size_t size,
+                                   const void *data)
+{
+  struct GetPseuAuthorityHandle *gph = cls;
+  const struct GNUNET_NAMESTORE_Block *block;
+
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Got DHT result for PSEU request\n");
+  GNUNET_DHT_get_stop (gph->get_handle);
+  gph->get_handle = NULL;
+  GNUNET_SCHEDULER_cancel (gph->timeout_task);
+  gph->timeout_task = GNUNET_SCHEDULER_NO_TASK;
+
+  if (NULL == data)
+  {
+    /* is this allowed!? */
+    GNUNET_break (0);
+    process_pseu_result (gph, NULL);
+    return;
+  }
+  if (size < sizeof (struct GNUNET_NAMESTORE_Block))
+  {
+    /* how did this pass DHT block validation!? */
+    GNUNET_break (0);
+    process_pseu_result (gph, NULL);
+    return;   
+  }
+  block = data;
+  if (size !=
+      ntohs (block->purpose.size) + 
+      sizeof (struct GNUNET_CRYPTO_EccPublicKey) +
+      sizeof (struct GNUNET_CRYPTO_EccSignature))
+  {
+    /* how did this pass DHT block validation!? */
+    GNUNET_break (0);
+    process_pseu_result (gph, NULL);
+    return;   
+  }
+  if (GNUNET_OK !=
+      GNUNET_NAMESTORE_block_decrypt (block,
+                                      &gph->target_zone,
+                                      GNUNET_GNS_TLD_PLUS,
+                                      &process_auth_records,
+                                      gph))
+  {
+    /* other peer encrypted invalid block, complain */
+    GNUNET_break_op (0);
+    process_pseu_result (gph, NULL);
+    return;   
+  }
+}
+
+
+/**
+ * Callback called by namestore for a zone to name result.  We're
+ * trying to see if a short name for a given zone already exists.
+ *
+ * @param cls the closure
+ * @param zone_key the zone we queried
+ * @param name the name found or NULL
+ * @param rd_len number of records for the name
+ * @param rd the record data (PKEY) for the name
+ */
+static void
+process_zone_to_name_discover (void *cls,
+                               const struct GNUNET_CRYPTO_EccPrivateKey *zone_key,
+                               const char *name,
+                               unsigned int rd_len,
+                               const struct GNUNET_NAMESTORE_RecordData *rd)
+{
+  struct GetPseuAuthorityHandle* gph = cls;
+  struct GNUNET_HashCode lookup_key;
+  
+  gph->namestore_task = NULL;
+  if (0 != rd_len)
+  {
+    /* we found a match in our own zone */
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                "Shortening aborted, name `%s' already reserved for the zone\n",
+                name);
+    free_get_pseu_authority_handle (gph);
+    return;
+  }
+  /* record does not yet exist, go into DHT to find PSEU record */
+  GNUNET_NAMESTORE_query_from_public_key (&gph->target_zone,
+                                          GNUNET_GNS_TLD_PLUS,                                    
+                                          &lookup_key);
+  gph->timeout_task = GNUNET_SCHEDULER_add_delayed (DHT_LOOKUP_TIMEOUT,
+                                                    &handle_auth_discovery_timeout, 
+                                                    gph);
+  gph->get_handle = GNUNET_DHT_get_start (dht_handle,
+                                          GNUNET_BLOCK_TYPE_GNS_NAMERECORD,
+                                          &lookup_key,
+                                          DHT_GNS_REPLICATION_LEVEL,
+                                          GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE,
+                                          NULL, 0,
+                                          &process_auth_discovery_dht_result,
+                                          gph);
+}
+
+
+/**
+ * Start shortening algorithm, try to allocate a nice short
+ * canonical name for @a pub in @a shorten_zone, using
+ * @a original_label as one possible suggestion.
+ *
+ * @param original_label original label for the zone
+ * @param pub public key of the zone to shorten
+ * @param shorten_zone private key of the target zone for the new record
+ */
+void
+GNS_shorten_start (const char *original_label,
+                   const struct GNUNET_CRYPTO_EccPublicKey *pub,
+                   const struct GNUNET_CRYPTO_EccPrivateKey *shorten_zone)
+{
+  struct GetPseuAuthorityHandle *gph;
+  
+  if (strlen (original_label) > GNUNET_DNSPARSER_MAX_LABEL_LENGTH)
+  {
+    GNUNET_break (0);
+    return;
+  }
+  gph = GNUNET_new (struct GetPseuAuthorityHandle);
+  gph->shorten_zone_key = *shorten_zone;
+  gph->target_zone = *pub;
+  strcpy (gph->label, original_label);
+  GNUNET_CONTAINER_DLL_insert (gph_head, gph_tail, gph);
+  /* first, check if we *already* have a record for this zone */
+  gph->namestore_task = GNUNET_NAMESTORE_zone_to_name (namestore_handle,
+                                                       shorten_zone,
+                                                       pub,
+                                                       &process_zone_to_name_discover,
+                                                       gph);
+}
+
+
+/**
+ * Initialize the shortening subsystem
+ *
+ * @param nh the namestore handle
+ * @param dht the dht handle
+ */
+void
+GNS_shorten_init (struct GNUNET_NAMESTORE_Handle *nh,
+                  struct GNUNET_DHT_Handle *dht)
+{
+  namestore_handle = nh;
+  dht_handle = dht;
+}
+
+
+/**
+ * Shutdown shortening.
+ */
+void
+GNS_shorten_done ()
+{
+  /* abort active shorten operations */
+  while (NULL != gph_head)
+    free_get_pseu_authority_handle (gph_head);
+  dht_handle = NULL;
+  namestore_handle = NULL;
+}
+
+/* end of gnunet-service-gns_shorten.c */
diff --git a/src/gns/gnunet-service-gns_shorten.h b/src/gns/gnunet-service-gns_shorten.h
new file mode 100644
index 000000000..d71100a88
--- /dev/null
+++ b/src/gns/gnunet-service-gns_shorten.h
@@ -0,0 +1,66 @@
+/*
+     This file is part of GNUnet.
+     (C) 2009-2013 Christian Grothoff (and other contributing authors)
+
+     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., 59 Temple Place - Suite 330,
+     Boston, MA 02111-1307, USA.
+*/
+/**
+ * @file gns/gnunet-service-gns_shorten.h
+ * @brief GNUnet GNS shortening API
+ * @author Martin Schanzenbach
+ */
+#ifndef GNS_SHORTEN_H
+#define GNS_SHORTEN_H
+#include "gns.h"
+#include "gnunet_dht_service.h"
+#include "gnunet_namestore_service.h"
+
+
+/**
+ * Initialize the shorten subsystem.
+ * MUST be called before #GNS_shorten_start.
+ *
+ * @param nh handle to the namestore
+ * @param dht handle to the dht
+ */
+void
+GNS_shorten_init (struct GNUNET_NAMESTORE_Handle *nh,
+                  struct GNUNET_DHT_Handle *dht);
+
+
+/**
+ * Cleanup shorten: Terminate pending lookups
+ */
+void
+GNS_shorten_done (void);
+
+
+/**
+ * Start shortening algorithm, try to allocate a nice short
+ * canonical name for @a pub in @a shorten_zone, using
+ * @a original_label as one possible suggestion.
+ *
+ * @param original_label original label for the zone
+ * @param pub public key of the zone to shorten
+ * @param shorten_zone private key of the target zone for the new record
+ */
+void
+GNS_shorten_start (const char *original_label,
+                   const struct GNUNET_CRYPTO_EccPublicKey *pub,
+                   const struct GNUNET_CRYPTO_EccPrivateKey *shorten_zone);
+
+
+#endif