1 files changed, 198 insertions, 0 deletions

diff --git a/src/lib/hello/hello-ng.c b/src/lib/hello/hello-ng.c
new file mode 100644
index 000000000..9c255b361
--- /dev/null
+++ b/src/lib/hello/hello-ng.c
@@ -0,0 +1,198 @@
+/*
+     This file is part of GNUnet.
+     Copyright (C) 2018 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
+ */
+
+/**
+ * @file hello/hello-ng.c
+ * @brief helper library for handling HELLOs
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "gnunet_signatures.h"
+#include "gnunet_hello_lib.h"
+#include "gnunet_protocols.h"
+#include "gnunet_util_lib.h"
+
+GNUNET_NETWORK_STRUCT_BEGIN
+/**
+ * Binary block we sign when we sign an address.
+ */
+struct SignedAddress
+{
+  /**
+   * Purpose must be #GNUNET_SIGNATURE_PURPOSE_TRANSPORT_ADDRESS
+   */
+  struct GNUNET_CRYPTO_EccSignaturePurpose purpose;
+
+  /**
+   * When was the address generated.
+   */
+  struct GNUNET_TIME_AbsoluteNBO mono_time;
+
+  /**
+   * Hash of the address.
+   */
+  struct GNUNET_HashCode addr_hash GNUNET_PACKED;
+};
+GNUNET_NETWORK_STRUCT_END
+
+/**
+ * Build address record by signing raw information with private key.
+ *
+ * @param address text address at @a communicator to sign
+ * @param nt network type of @a address
+ * @param mono_time monotonic time at which @a address was valid
+ * @param private_key signing key to use
+ * @param[out] result where to write address record (allocated)
+ * @param[out] result_size set to size of @a result
+ */
+void
+GNUNET_HELLO_sign_address (
+  const char *address,
+  enum GNUNET_NetworkType nt,
+  struct GNUNET_TIME_Absolute mono_time,
+  const struct GNUNET_CRYPTO_EddsaPrivateKey *private_key,
+  void **result,
+  size_t *result_size)
+{
+  struct SignedAddress sa;
+  struct GNUNET_CRYPTO_EddsaSignature sig;
+  char *sig_str;
+
+  sa.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_TRANSPORT_ADDRESS);
+  sa.purpose.size = htonl (sizeof(sa));
+  sa.mono_time = GNUNET_TIME_absolute_hton (mono_time);
+  GNUNET_CRYPTO_hash (address, strlen (address), &sa.addr_hash);
+  GNUNET_CRYPTO_eddsa_sign (private_key, &sa, &sig);
+  sig_str = NULL;
+  (void) GNUNET_STRINGS_base64_encode (&sig, sizeof(sig), &sig_str);
+  *result_size =
+    1 + GNUNET_asprintf ((char **) result,
+                         "%s;%llu;%u;%s",
+                         sig_str,
+                         (unsigned long long) mono_time.abs_value_us,
+                         (unsigned int) nt,
+                         address);
+  GNUNET_free (sig_str);
+}
+
+
+/**
+ * Check signature and extract address record.
+ *
+ * @param raw raw signed address
+ * @param raw_size size of @a raw
+ * @param pid public key to use for signature verification
+ * @param nt[out] set to network type
+ * @param mono_time[out] when was the address generated
+ * @return NULL on error, otherwise the address
+ */
+char *
+GNUNET_HELLO_extract_address (const void *raw,
+                              size_t raw_size,
+                              const struct GNUNET_PeerIdentity *pid,
+                              enum GNUNET_NetworkType *nt,
+                              struct GNUNET_TIME_Absolute *mono_time)
+{
+  const struct GNUNET_CRYPTO_EddsaPublicKey *public_key = &pid->public_key;
+  const char *raws = raw;
+  unsigned long long raw_us = 0;
+  unsigned int raw_nt = 0;
+  const char *sc;
+  const char *sc2;
+  const char *sc3;
+  const char *raw_addr;
+  char *data = NULL;
+  struct GNUNET_TIME_Absolute raw_mono_time;
+  struct SignedAddress sa;
+  struct GNUNET_CRYPTO_EddsaSignature *sig;
+
+  if ('\0' != raws[raw_size-1])
+  {
+    GNUNET_break_op (0);
+    return NULL;
+  }
+  if (NULL == (sc = strchr (raws, ';')))
+  {
+    GNUNET_break_op (0);
+    return NULL;
+  }
+  if (NULL == (sc2 = strchr (sc + 1, ';')))
+  {
+    GNUNET_break_op (0);
+    return NULL;
+  }
+  if (NULL == (sc3 = strchr (sc2 + 1, ';')))
+  {
+    GNUNET_break_op (0);
+    return NULL;
+  }
+  if (2 != sscanf (sc + 1, "%llu;%u;%*s", &raw_us, &raw_nt))
+  {
+    GNUNET_break_op (0);
+    return NULL;
+  }
+  raw_addr = sc3 + 1;
+  raw_mono_time.abs_value_us = raw_us;
+    if (sizeof(struct GNUNET_CRYPTO_EddsaSignature) !=
+      GNUNET_STRINGS_base64_decode (raws, sc - raws, (void **) &data))
+  {
+    GNUNET_break_op (0);
+    GNUNET_free (data);
+    return NULL;
+  }
+  sig = (struct GNUNET_CRYPTO_EddsaSignature*) data;
+  sa.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_TRANSPORT_ADDRESS);
+  sa.purpose.size = htonl (sizeof(sa));
+  sa.mono_time = GNUNET_TIME_absolute_hton (raw_mono_time);
+  GNUNET_CRYPTO_hash (raw_addr, strlen (raw_addr), &sa.addr_hash);
+  if (GNUNET_YES !=
+      GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_TRANSPORT_ADDRESS,
+                                  &sa,
+                                  sig,
+                                  public_key))
+  {
+    GNUNET_free (data);
+    GNUNET_break_op (0);
+    return NULL;
+  }
+  GNUNET_free (data);
+  *mono_time = raw_mono_time;
+  *nt = raw_nt;
+  return GNUNET_strdup (raw_addr);
+}
+
+
+/**
+ * Given an address as a string, extract the prefix that identifies
+ * the communicator offering transmissions to that address.
+ *
+ * @param address a peer's address
+ * @return NULL if the address is mal-formed, otherwise the prefix
+ */
+char *
+GNUNET_HELLO_address_to_prefix (const char *address)
+{
+  const char *dash;
+
+  dash = strchr (address, '-');
+  if (NULL == dash)
+    return NULL;
+  return GNUNET_strndup (address, dash - address);
+}