exchange

tv_age_restriction.c (7008B)

---

 /**
  * @file util/tv_age_restriction.c
  * @brief Generate test vectors for age restriction
  * @author Özgür Kesim
  *
  * compile in exchange/src/util with
  *
  * gcc tv_age_restriction.c \
  *    -lgnunetutil -lgnunetjson -lsodium -ljansson \
  *    -L/usr/lib/x86_64-linux-gnu -lmicrohttpd -ltalerutil \
  *    -I../include \
  *    -o tv_age_restriction
  *
  */
 #include "taler/platform.h"
 #include <gnunet/gnunet_json_lib.h>
 #include <gnunet/gnunet_util_lib.h>
 #include <jansson.h>
 #include <taler/taler_util.h>
 #include <taler/taler_crypto_lib.h>
 
 static struct TALER_AgeMask age_masks[] = {
   { .bits = 1
             | 1 << 8 | 1 << 14 | 1 << 18 },
   { .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);
 
 /**
  * Encodes the age mask into a string, like "8:10:12:14:16:18:21"
  */
 char *
 age_mask_to_string (
   const struct TALER_AgeMask *mask)
 {
   uint32_t bits = mask->bits;
   unsigned int n = 0;
   char *buf = GNUNET_malloc (32 * 3); // max characters possible
   char *pos = buf;
 
   if (NULL == buf)
   {
     return buf;
   }
 
   while (bits != 0)
   {
     bits >>= 1;
     n++;
     if (0 == (bits & 1))
     {
       continue;
     }
 
     if (n > 9)
     {
       *(pos++) = '0' + n / 10;
     }
     *(pos++) = '0' + n % 10;
 
     if (0 != (bits >> 1))
     {
       *(pos++) = ':';
     }
   }
   return buf;
 }
 
 
 static json_t *
 cp_to_j (
   const struct GNUNET_HashCode *seed,
   struct TALER_AgeCommitmentProof *acp,
   uint8_t seq)
 {
   json_t *j_commitment;
   json_t *j_proof;
   json_t *j_pubs;
   json_t *j_privs;
   struct TALER_AgeCommitmentHashP hac = {0};
   char buf[256] = {0};
 
   TALER_age_commitment_hash (&acp->commitment, &hac);
 
   j_pubs = json_array ();
   GNUNET_assert (NULL != j_pubs);
   for (unsigned int i = 0; i < acp->commitment.num; i++)
   {
     json_t *j_pub = GNUNET_JSON_PACK (
       GNUNET_JSON_pack_data_auto (NULL,
                                   &acp->commitment.keys[i]));
     json_array_append_new (j_pubs, j_pub);
   }
 
   j_commitment = GNUNET_JSON_PACK (
     GNUNET_JSON_pack_uint64 ("num", acp->commitment.num),
     GNUNET_JSON_pack_array_steal ("edx25519_pubs", j_pubs),
     GNUNET_JSON_pack_data_auto ("h_age_commitment", &hac));
 
 
   j_privs = json_array ();
   GNUNET_assert (NULL != j_privs);
   for (unsigned int i = 0; i < acp->proof.num; i++)
   {
     json_t *j_priv = GNUNET_JSON_PACK (
       GNUNET_JSON_pack_data_auto (NULL,
                                   &acp->proof.keys[i]));
     json_array_append_new (j_privs, j_priv);
   }
   j_proof = GNUNET_JSON_PACK (
     GNUNET_JSON_pack_uint64 ("num", acp->proof.num),
     GNUNET_JSON_pack_array_steal ("edx25519_privs", j_privs));
 
   if (0 == seq)
   {
     strcpy (buf, "commit()");
   }
   else
   {
     sprintf (buf,
              "derive_from(%d)",
              seq);
   }
 
   return GNUNET_JSON_PACK (
     GNUNET_JSON_pack_string ("generated_by", buf),
     GNUNET_JSON_pack_data_auto ("seed", seed),
     GNUNET_JSON_pack_object_steal ("proof", j_proof),
     GNUNET_JSON_pack_object_steal ("commitment", j_commitment));
 
 };
 
 static json_t *
 generate (
   struct TALER_AgeMask *mask)
 {
   uint8_t age;
   json_t *j_commitproofs;
   j_commitproofs = json_array ();
 
   for (age = 0; age < 24; age += 2)
   {
     json_t *j_top = json_object ();
     json_t *j_seq = json_array ();
     enum GNUNET_GenericReturnValue ret;
     struct TALER_AgeCommitmentProof acp[3] = {0};
     uint8_t age_group = get_age_group (mask, age);
     struct GNUNET_HashCode seed;
 
     GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_WEAK,
                                 &seed,
                                 sizeof(seed));
 
     json_object_set (j_top,
                      "committed_age",
                      json_integer (age));
 
     ret = TALER_age_restriction_commit (mask,
                                         age,
                                         &seed,
                                         &acp[0]);
 
     GNUNET_assert (GNUNET_OK == ret);
 
     /* Also derive two more commitments right away */
     for (uint8_t i = 0; i<2; i++)
     {
       struct GNUNET_HashCode salt;
       GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_WEAK,
                                   &salt,
                                   sizeof (salt));
       GNUNET_assert (GNUNET_OK ==
                      TALER_age_commitment_derive (&acp[i],
                                                   &salt,
                                                   &acp[i + 1]));
     }
 
     for (uint8_t i = 0; i < 3; i++)
     {
       json_t *j_cp = cp_to_j (&seed, &acp[i], i);
       json_t *j_attestations = json_array ();
 
       for (uint8_t min = 0; min < 22; min++)
       {
         json_t *j_attest = json_object ();
         json_t *j_reason;
         uint8_t min_group = get_age_group (mask, min);
         struct TALER_AgeAttestationP at = {0};
 
         json_object_set (j_attest,
                          "required_minimum_age",
                          json_integer (min));
         json_object_set (j_attest,
                          "calculated_age_group",
                          json_integer (min_group));
 
         ret = TALER_age_commitment_attest (&acp[i],
                                            min,
                                            &at);
 
 
         if (0 == min_group)
           j_reason =  json_string (
             "not required: age group is 0");
         else if (min_group > age_group)
           j_reason = json_string (
             "not applicable: committed age too small");
         else
           j_reason = GNUNET_JSON_PACK (
             GNUNET_JSON_pack_data_auto (NULL, &at));
 
         json_object_set (j_attest,
                          "attestation",
                          j_reason);
 
         json_array_append_new (j_attestations,
                                j_attest);
 
       }
 
       json_object_set (j_cp, "attestations", j_attestations);
       json_array_append (j_seq,  j_cp);
 
       TALER_age_commitment_proof_free (&acp[i]);
     }
 
     json_object_set (j_top, "commitment_proof_attestation_seq", j_seq);
     json_array_append_new (j_commitproofs, j_top);
   }
 
   return j_commitproofs;
 }
 
 
 int
 main (int argc,
       const char *const argv[])
 {
   (void) argc;
   (void) argv;
   json_t *j_data = json_array ();
   for (unsigned int i = 0; i < 2; i++)
   {
     struct TALER_AgeMask mask = age_masks[i];
     json_t *j_test = json_object ();
     json_object_set (j_test,
                      "age_groups",
                      json_string (age_mask_to_string (&mask)));
     json_object_set (j_test,
                      "age_mask",
                      json_integer (mask.bits));
     json_object_set (j_test,
                      "test_data",
                      generate (&mask));
     json_array_append_new (j_data, j_test);
   }
   printf ("%s\n", json_dumps (j_data, JSON_INDENT (2)
                               | JSON_COMPACT));
 
   json_decref (j_data);
   return 0;
 }
 
 
 /* end of tv_age_restriction.c */