add token issue sig helper

5 files changed, 184 insertions, 1 deletions

diff --git a/src/include/taler_crypto_lib.h b/src/include/taler_crypto_lib.h
index bd7164ca5..429cf1cc0 100644
--- a/src/include/taler_crypto_lib.h
+++ b/src/include/taler_crypto_lib.h
@@ -5961,7 +5961,7 @@ struct TALER_TokenUseSignature
  */
 struct TALER_TokenIssueSignature
 {
-  struct GNUNET_CRYPTO_UnblindedSignature signature;
+  struct GNUNET_CRYPTO_UnblindedSignature *signature;
 };
 
 /**
@@ -5972,4 +5972,12 @@ struct TALER_TokenIssueBlindSignature
   struct GNUNET_CRYPTO_BlindedSignature signature;
 };
 
+/**
+ * Free internals of @a issue_sig, but not @a issue_sig itself.
+ *
+ * @param[in] issue_sig signature to free
+ */
+void
+TALER_token_issue_sig_free (struct TALER_TokenIssueSignature *issue_sig);
+
 #endif
diff --git a/src/include/taler_json_lib.h b/src/include/taler_json_lib.h
index 98e565f0c..dad493cb6 100644
--- a/src/include/taler_json_lib.h
+++ b/src/include/taler_json_lib.h
@@ -588,6 +588,18 @@ TALER_JSON_spec_i18n_str (const char *name,
 
 
 /**
+ * Generate line in parser specification for a
+ * token issue signature.
+ *
+ * @param field name of the field
+ * @param[out] sig the signature to initialize
+ * @return corresponding field spec
+ */
+struct GNUNET_JSON_Specification
+TALER_JSON_spec_token_issue_sig (const char *field,
+                                 struct TALER_TokenIssueSignature *sig);
+
+/**
  * Hash a JSON for binary signing.
  *
  * See https://tools.ietf.org/html/draft-rundgren-json-canonicalization-scheme-15
diff --git a/src/json/json_helper.c b/src/json/json_helper.c
index 0a533610b..f58d5fa5c 100644
--- a/src/json/json_helper.c
+++ b/src/json/json_helper.c
@@ -533,6 +533,135 @@ TALER_JSON_spec_age_commitment (const char *name,
 
 
 /**
+ * Parse given JSON object to token issue signature.
+ * TODO: Exctract common between this and parse_denom_sig function to a helper.
+ *
+ * @param cls closure, NULL
+ * @param root the json object representing data
+ * @param[out] spec where to write the data
+ * @return #GNUNET_OK upon successful parsing; #GNUNET_SYSERR upon error
+ */
+static enum GNUNET_GenericReturnValue
+parse_token_issue_sig (void *cls,
+                       json_t *root,
+                       struct GNUNET_JSON_Specification *spec)
+{
+  struct TALER_TokenIssueSignature *issue_sig = spec->ptr;
+  struct GNUNET_CRYPTO_UnblindedSignature *unblinded_sig;
+  const char *cipher;
+  struct GNUNET_JSON_Specification dspec[] = {
+    GNUNET_JSON_spec_string ("cipher",
+                             &cipher),
+    GNUNET_JSON_spec_end ()
+  };
+  const char *emsg;
+  unsigned int eline;
+
+  (void) cls;
+  if (GNUNET_OK !=
+      GNUNET_JSON_parse (root,
+                         dspec,
+                         &emsg,
+                         &eline))
+  {
+    GNUNET_break_op (0);
+    return GNUNET_SYSERR;
+  }
+  unblinded_sig = GNUNET_new (struct GNUNET_CRYPTO_UnblindedSignature);
+  unblinded_sig->cipher = string_to_cipher (cipher);
+  unblinded_sig->rc = 1;
+  switch (unblinded_sig->cipher)
+  {
+  case GNUNET_CRYPTO_BSA_INVALID:
+    break;
+  case GNUNET_CRYPTO_BSA_RSA:
+    {
+      struct GNUNET_JSON_Specification ispec[] = {
+        GNUNET_JSON_spec_rsa_signature (
+          "rsa_signature",
+          &unblinded_sig->details.rsa_signature),
+        GNUNET_JSON_spec_end ()
+      };
+
+      if (GNUNET_OK !=
+          GNUNET_JSON_parse (root,
+                             ispec,
+                             &emsg,
+                             &eline))
+      {
+        GNUNET_break_op (0);
+        GNUNET_free (unblinded_sig);
+        return GNUNET_SYSERR;
+      }
+      issue_sig->signature = unblinded_sig;
+      return GNUNET_OK;
+    }
+  case GNUNET_CRYPTO_BSA_CS:
+    {
+      struct GNUNET_JSON_Specification ispec[] = {
+        GNUNET_JSON_spec_fixed_auto ("cs_signature_r",
+                                     &unblinded_sig->details.cs_signature.
+                                     r_point),
+        GNUNET_JSON_spec_fixed_auto ("cs_signature_s",
+                                     &unblinded_sig->details.cs_signature.
+                                     s_scalar),
+        GNUNET_JSON_spec_end ()
+      };
+
+      if (GNUNET_OK !=
+          GNUNET_JSON_parse (root,
+                             ispec,
+                             &emsg,
+                             &eline))
+      {
+        GNUNET_break_op (0);
+        GNUNET_free (unblinded_sig);
+        return GNUNET_SYSERR;
+      }
+      issue_sig->signature = unblinded_sig;
+      return GNUNET_OK;
+    }
+  }
+  GNUNET_break_op (0);
+  GNUNET_free (unblinded_sig);
+  return GNUNET_SYSERR;
+}
+
+
+/**
+ * Cleanup data left from parsing token issue signature.
+ *
+ * @param cls closure, NULL
+ * @param[out] spec where to free the data
+ */
+static void
+clean_token_issue_sig (void *cls,
+                       struct GNUNET_JSON_Specification *spec)
+{
+  struct TALER_TokenIssueSignature *issue_sig = spec->ptr;
+
+  (void) cls;
+  TALER_token_issue_sig_free (issue_sig);
+}
+
+
+struct GNUNET_JSON_Specification
+TALER_JSON_spec_token_issue_sig (const char *field,
+                                 struct TALER_TokenIssueSignature *sig)
+{
+  struct GNUNET_JSON_Specification ret = {
+    .parser = &parse_token_issue_sig,
+    .cleaner = &clean_token_issue_sig,
+    .field = field,
+    .ptr = sig
+  };
+
+  sig->signature = NULL;
+  return ret;
+}
+
+
+/**
  * Parse given JSON object to denomination public key.
  *
  * @param cls closure, NULL
diff --git a/src/util/Makefile.am b/src/util/Makefile.am
index d2504588b..897a821b1 100644
--- a/src/util/Makefile.am
+++ b/src/util/Makefile.am
@@ -102,6 +102,7 @@ libtalerutil_la_SOURCES = \
   payto.c \
   secmod_signatures.c \
   taler_error_codes.c \
+  tokens.c \
   url.c \
   util.c \
   wallet_signatures.c \
diff --git a/src/util/tokens.c b/src/util/tokens.c
new file mode 100644
index 000000000..61fe40501
--- /dev/null
+++ b/src/util/tokens.c
@@ -0,0 +1,33 @@
+/*
+  This file is part of TALER
+  Copyright (C) 2024 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 tokens.c
+ * @brief token family utility functions
+ * @author Christian Blättler
+ */
+#include "platform.h"
+#include "taler_util.h"
+
+
+void
+TALER_token_issue_sig_free (struct TALER_TokenIssueSignature *issue_sig)
+{
+  if (NULL != issue_sig->signature)
+  {
+    GNUNET_CRYPTO_unblinded_sig_decref (issue_sig->signature);
+    issue_sig->signature = NULL;
+  }
+}