[age restriction] progress 18/n - attestation tested

- Unit-tests for commit, derive, attest and verify added, with multiple
  combinations of minimum age and commited age.
- Fixed crypto implementation (eddsa -> ecdsa)
- Using now standard functionality from GNUNET:
  GNUNET_CRYPTO_ecdsa_{private,public}_key_derive

All tests pass (unit tests in util/ and 'make check' in testing).

1 files changed, 135 insertions, 0 deletions

diff --git a/src/util/test_age_restriction.c b/src/util/test_age_restriction.c
new file mode 100644
index 000000000..a047714f7
--- /dev/null
+++ b/src/util/test_age_restriction.c
@@ -0,0 +1,135 @@
+/*
+  This file is part of TALER
+  (C) 2022 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 util/test_age_restriction.c
+ * @brief Tests for age restriction specific logic
+ * @author Özgür Kesim
+ */
+#include "platform.h"
+#include "taler_util.h"
+#include "taler_crypto_lib.h"
+
+static struct TALER_AgeMask age_mask = {
+  .bits = 1 | 1 << 8 | 1 << 10 | 1 << 12 | 1 << 14 | 1 << 16 | 1 << 18 | 1 << 21
+};
+
+extern uint8_t
+get_age_group (
+  const struct TALER_AgeMask *mask,
+  uint8_t age);
+
+enum GNUNET_GenericReturnValue
+test_attestation (void)
+{
+  uint8_t age;
+  for (age = 0; age < 35; age++)
+  {
+    enum GNUNET_GenericReturnValue ret;
+    struct TALER_AgeCommitmentProof acp[3] = {0};
+    struct TALER_AgeAttestation at = {0};
+    uint8_t age_group = get_age_group (&age_mask, age);
+    uint64_t salt = GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_WEAK,
+                                              UINT64_MAX);
+
+    ret = TALER_age_restriction_commit (&age_mask,
+                                        age,
+                                        salt,
+                                        &acp[0]);
+
+    printf (
+      "commit(age:%d) == %d; proof.num: %ld; age_group: %d\n",
+      age,
+      ret,
+      acp[0].proof.num,
+      age_group);
+
+    for (uint8_t i = 0; i<2; i++)
+    {
+      /* Also derive another commitment right away */
+      salt = GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_WEAK,
+                                       UINT64_MAX);
+      GNUNET_assert (GNUNET_OK ==
+                     TALER_age_commitment_derive (&acp[i],
+                                                  salt,
+                                                  &acp[i + 1]));
+    }
+
+    for (uint8_t i = 0; i < 3; i++)
+    {
+      for (uint8_t min = 0; min < 22; min++)
+      {
+        uint8_t min_group = get_age_group (&age_mask, min);
+
+        ret = TALER_age_commitment_attest (&acp[i],
+                                           min,
+                                           &at);
+
+        printf (
+          "[%s]: attest(min:%d, age:%d) == %d; age_group: %d, min_group: %d\n",
+          i == 0 ? "commit" : "derive",
+          min,
+          age,
+          ret,
+          age_group,
+          min_group);
+
+        if (min_group <= age_group &&
+            GNUNET_OK != ret)
+          return GNUNET_SYSERR;
+
+        if (min_group > age_group &&
+            GNUNET_NO != ret)
+          return GNUNET_SYSERR;
+
+        if (min_group > age_group)
+          continue;
+
+        ret = TALER_age_commitment_verify (&acp[i].commitment,
+                                           min,
+                                           &at);
+
+        printf (
+          "[%s]: verify(min:%d, age:%d) == %d; age_group:%d, min_group: %d\n",
+          i == 0 ? "commit" : "derive",
+          min,
+          age,
+          ret,
+          age_group,
+          min_group);
+
+        if (GNUNET_OK != ret)
+          return ret;
+      }
+    }
+  }
+  return GNUNET_OK;
+}
+
+
+int
+main (int argc,
+      const char *const argv[])
+{
+  (void) argc;
+  (void) argv;
+  if (GNUNET_OK != test_attestation ())
+    return 1;
+  return 0;
+}
+
+
+/* end of test_age_restriction.c */