1 files changed, 193 insertions, 0 deletions
diff --git a/src/json/json_wire.c b/src/json/json_wire.c
new file mode 100644
index 000000000..f0bd17578
--- /dev/null
+++ b/src/json/json_wire.c
@@ -0,0 +1,193 @@
+/*
+  This file is part of TALER
+  Copyright (C) 2018 Taler Systems SA
+
+  TALER 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.
+
+  TALER 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
+  TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+*/
+/**
+ * @file json/json_wire.c
+ * @brief helper functions to generate or check /wire replies
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include <gnunet/gnunet_util_lib.h>
+#include "taler_util.h"
+#include "taler_json_lib.h"
+#include "taler_wire_lib.h"
+
+
+/**
+ * Compute the hash of the given wire details.   The resulting
+ * hash is what is put into the contract.
+ *
+ * @param wire_s wire details to hash
+ * @param hc[out] set to the hash
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR if @a wire_s is malformed
+ */
+int
+TALER_JSON_wire_signature_hash (const json_t *wire_s,
+                                struct GNUNET_HashCode *hc)
+{
+  const char *payto_url;
+  const char *salt;
+  struct GNUNET_JSON_Specification spec[] = {
+    GNUNET_JSON_spec_string ("url", &payto_url),
+    GNUNET_JSON_spec_string ("salt", &salt),
+    GNUNET_JSON_spec_end ()
+  };
+
+  if (GNUNET_OK !=
+      GNUNET_JSON_parse (wire_s,
+                         spec,
+                         NULL, NULL))
+  {
+    GNUNET_break_op (0);
+    return GNUNET_SYSERR;
+  }
+  TALER_wire_signature_hash (payto_url,
+                             salt,
+                             hc);
+  return GNUNET_OK;
+}
+
+
+/**
+ * Check the signature in @a wire_s.
+ *
+ * @param wire_s signed wire information of an exchange
+ * @param master_pub master public key of the exchange
+ * @return #GNUNET_OK if signature is valid
+ */
+int
+TALER_JSON_wire_signature_check (const json_t *wire_s,
+                                 const struct TALER_MasterPublicKeyP *master_pub)
+{
+  const char *payto_url;
+  const char *salt;
+  struct TALER_MasterSignatureP master_sig;
+  struct GNUNET_JSON_Specification spec[] = {
+    GNUNET_JSON_spec_string ("url", &payto_url),
+    GNUNET_JSON_spec_string ("salt", &salt),
+    GNUNET_JSON_spec_fixed_auto ("master_sig", &master_sig),
+    GNUNET_JSON_spec_end ()
+  };
+
+  if (GNUNET_OK !=
+      GNUNET_JSON_parse (wire_s,
+                         spec,
+                         NULL, NULL))
+  {
+    GNUNET_break_op (0);
+    return GNUNET_SYSERR;
+  }
+  return TALER_wire_signature_check (payto_url,
+                                     salt,
+                                     master_pub,
+                                     &master_sig);
+}
+
+
+/**
+ * Create a signed wire statement for the given account.
+ *
+ * @param payto_url account specification
+ * @param master_priv private key to sign with, NULL to not sign
+ */
+json_t *
+TALER_JSON_wire_signature_make (const char *payto_url,
+                                const struct TALER_MasterPrivateKeyP *master_priv)
+{
+  struct TALER_MasterSignatureP master_sig;
+  struct GNUNET_HashCode salt;
+  char *salt_str;
+  json_t *ret;
+
+  GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE,
+                              &salt,
+                              sizeof (salt));
+  salt_str = GNUNET_STRINGS_data_to_string_alloc (&salt,
+                                                  sizeof (salt));
+  if (NULL != master_priv)
+  {
+    TALER_wire_signature_make (payto_url,
+                               salt_str,
+                               master_priv,
+                               &master_sig);
+    ret = json_pack ("{s:s, s:s, s:o}",
+                     "url", payto_url,
+                     "salt", salt_str,
+                     "master_sig", GNUNET_JSON_from_data_auto (&master_sig));
+  }
+  else
+  {
+    ret = json_pack ("{s:s, s:s}",
+                     "url", payto_url,
+                     "salt", salt_str);
+  }
+  GNUNET_free (salt_str);
+  return ret;
+}
+
+
+/**
+ * Obtain the wire method associated with the given
+ * wire account details.  @a wire_s must contain a payto://-URL
+ * under 'url'.
+ *
+ * @return NULL on error
+ */
+char *
+TALER_JSON_wire_to_payto (const json_t *wire_s)
+{
+  json_t *payto_o;
+  const char *payto_str;
+
+  payto_o = json_object_get (wire_s,
+                             "url");
+  if ( (NULL == payto_o) ||
+       (NULL == (payto_str = json_string_value (payto_o))) )
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Fatally malformed wire record encountered: lacks payto://-url\n");
+    return NULL;
+  }
+  return GNUNET_strdup (payto_str);
+}
+
+
+/**
+ * Obtain the wire method associated with the given
+ * wire account details.  @a wire_s must contain a payto://-URL
+ * under 'url'.
+ *
+ * @return NULL on error
+ */
+char *
+TALER_JSON_wire_to_method (const json_t *wire_s)
+{
+  json_t *payto_o;
+  const char *payto_str;
+
+  payto_o = json_object_get (wire_s,
+                             "url");
+  if ( (NULL == payto_o) ||
+       (NULL == (payto_str = json_string_value (payto_o))) )
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Fatally malformed wire record encountered: lacks payto://-url\n");
+    return NULL;
+  }
+  return TALER_WIRE_payto_get_method (payto_str);
+}
+
+
+/* end of json_wire.c */