age restriction progress 2/n

Signed-off-by: Özgür Kesim <oec-taler@kesim.org>

15 files changed, 168 insertions, 27 deletions

diff --git a/src/include/taler_amount_lib.h b/src/include/taler_amount_lib.h
index c1f42e473..c6d2f474e 100644
--- a/src/include/taler_amount_lib.h
+++ b/src/include/taler_amount_lib.h
@@ -21,6 +21,9 @@
 #ifndef TALER_AMOUNT_LIB_H
 #define TALER_AMOUNT_LIB_H
 
+#include <stdint.h>
+#include "gnunet/gnunet_common.h"
+
 #ifdef __cplusplus
 extern "C"
 {
diff --git a/src/include/taler_crypto_lib.h b/src/include/taler_crypto_lib.h
index c521541fe..7261d4de5 100644
--- a/src/include/taler_crypto_lib.h
+++ b/src/include/taler_crypto_lib.h
@@ -280,6 +280,37 @@ struct TALER_MasterSignatureP
   struct GNUNET_CRYPTO_EddsaSignature eddsa_signature;
 };
 
+/*
+ * @brief Type of a list of age groups, represented as bit mask.
+ *
+ * The bits set in the mask mark the edges at the beginning of a next age
+ * group.  F.e. for the age groups
+ *     0-7, 8-9, 10-11, 12-14, 14-15, 16-17, 18-21, 21-*
+ * the following bits are set:
+ *
+ *   31     24        16        8         0
+ *   |      |         |         |         |
+ *   oooooooo  oo1oo1o1  o1o1o1o1  ooooooo1
+ *
+ * A value of 0 means that the exchange does not support the extension for
+ * age-restriction.
+ */
+struct TALER_AgeMask
+{
+  uint32_t mask;
+};
+
+/**
+ * @brief Age restriction commitment of a coin.
+ */
+struct TALER_AgeHash
+{
+  /**
+   * The commitment is a SHA-256 hash code.
+   */
+  struct GNUNET_ShortHashCode shash;
+};
+
 
 /**
  * @brief Type of public keys for Taler coins.  The same key material is used
@@ -292,6 +323,10 @@ struct TALER_CoinSpendPublicKeyP
    */
   struct GNUNET_CRYPTO_EddsaPublicKey eddsa_pub;
 
+  /*
+   * If age restriction applies to the coin, it must come with a hash of the age commitment
+   */
+  struct TALER_AgeHash age_commitment_hash;
 };
 
 
@@ -346,18 +381,6 @@ struct TALER_RefreshCommitmentP
 
 
 /**
- * Age restriction commitment of a coin.
- */
-struct TALER_AgeHash
-{
-  /**
-   * The commitment is a SHA-256 hash code.
-   */
-  struct GNUNET_ShortHashCode shash;
-};
-
-
-/**
  * Token used for access control to the merchant's unclaimed
  * orders.
  */
@@ -569,7 +592,7 @@ struct TALER_DenominationPublicKey
   /**
    * Age restriction mask used for the key.
    */
-  uint32_t age_mask;
+  struct TALER_AgeMask age_mask;
 
   /**
    * Details, depending on @e cipher.
@@ -631,6 +654,11 @@ struct TALER_CoinPublicInfo
   struct TALER_DenominationHash denom_pub_hash;
 
   /**
+   * Hash of the age commitment.
+   */
+  struct TALER_AgeHash age_commitment_hash;
+
+  /**
    * (Unblinded) signature over @e coin_pub with @e denom_pub,
    * which demonstrates that the coin is valid.
    */
@@ -880,7 +908,7 @@ TALER_blinded_denom_sig_cmp (
  */
 void
 TALER_denom_priv_to_pub (const struct TALER_DenominationPrivateKey *denom_priv,
-                         uint32_t age_mask,
+                         const struct TALER_AgeMask age_mask,
                          struct TALER_DenominationPublicKey *denom_pub);
 
 
@@ -929,7 +957,6 @@ TALER_coin_ev_hash (const void *coin_ev,
 
 /**
  * Compute the hash of a coin.
- * FIXME-Oec: add age restriction hash here!
  *
  * @param coin_pub public key of the coin
  * @param[out] coin_h where to write the hash
@@ -1020,6 +1047,9 @@ struct TALER_FreshCoin
    */
   struct TALER_CoinSpendPrivateKeyP coin_priv;
 
+  /**
+   * FIXME-Oec: Age-verification vector, as pointer: Dyn alloc!
+   */
 };
 
 
diff --git a/src/include/taler_extensions.h b/src/include/taler_extensions.h
new file mode 100644
index 000000000..c22a23b86
--- /dev/null
+++ b/src/include/taler_extensions.h
@@ -0,0 +1,35 @@
+/*
+  This file is part of TALER
+  Copyright (C) 2014-2021 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 include/taler_extensions.h
+ * @brief Interface for extensions
+ * @author Özgür Kesim
+ */
+#ifndef TALER_EXTENSIONS_H
+#define TALER_EXTENSIONS_H
+
+/**
+ *
+ * @param cfg
+ * @param[out] mask for age restriction
+ * @return Error if extension for age restriction was set but age groups were
+ *         invalid, OK otherwise.
+ */
+enum GNUNET_GenericReturnValue
+TALER_get_age_mask (const struct GNUNET_CONFIGURATION_Handle *cfg, struct
+                    TALER_AgeMask *mask);
+
+#endif
diff --git a/src/json/json_helper.c b/src/json/json_helper.c
index 1684e7f35..468d13569 100644
--- a/src/json/json_helper.c
+++ b/src/json/json_helper.c
@@ -444,7 +444,7 @@ parse_denom_pub (void *cls,
     GNUNET_JSON_spec_uint32 ("cipher",
                              &cipher),
     GNUNET_JSON_spec_uint32 ("age_mask",
-                             &denom_pub->age_mask),
+                             &denom_pub->age_mask.mask),
     GNUNET_JSON_spec_end ()
   };
   const char *emsg;
diff --git a/src/json/json_pack.c b/src/json/json_pack.c
index 59e3afb77..f41ba5234 100644
--- a/src/json/json_pack.c
+++ b/src/json/json_pack.c
@@ -104,7 +104,7 @@ TALER_JSON_pack_denom_pub (
           GNUNET_JSON_pack_uint64 ("cipher",
                                    TALER_DENOMINATION_RSA),
           GNUNET_JSON_pack_uint64 ("age_mask",
-                                   pk->age_mask),
+                                   pk->age_mask.mask),
           GNUNET_JSON_pack_rsa_public_key ("rsa_public_key",
                                            pk->details.rsa_public_key));
     break;
diff --git a/src/lib/exchange_api_deposit.c b/src/lib/exchange_api_deposit.c
index e857c8ea1..39397425a 100644
--- a/src/lib/exchange_api_deposit.c
+++ b/src/lib/exchange_api_deposit.c
@@ -462,9 +462,9 @@ handle_deposit_finished (void *cls,
  * @param h_wire hash of the merchant’s account details
  * @param h_contract_terms hash of the contact of the merchant with the customer (further details are never disclosed to the exchange)
  * @param coin_pub coin’s public key
+ * @param denom_sig exchange’s unblinded signature of the coin
  * @param denom_pub denomination key with which the coin is signed
  * @param denom_pub_hash hash of @a denom_pub
- * @param denom_sig exchange’s unblinded signature of the coin
  * @param timestamp timestamp when the deposit was finalized
  * @param merchant_pub the public key of the merchant (used to identify the merchant for refund requests)
  * @param refund_deadline date until which the merchant can issue a refund to the customer via the exchange (can be zero if refunds are not allowed)
@@ -512,7 +512,8 @@ verify_signatures (const struct TALER_EXCHANGE_DenomPublicKey *dki,
     struct TALER_CoinPublicInfo coin_info = {
       .coin_pub = *coin_pub,
       .denom_pub_hash = *denom_pub_hash,
-      .denom_sig = *denom_sig
+      .denom_sig = *denom_sig,
+      .age_commitment_hash = coin_pub->age_commitment_hash
     };
 
     if (GNUNET_YES !=
diff --git a/src/lib/exchange_api_refreshes_reveal.c b/src/lib/exchange_api_refreshes_reveal.c
index c275e0a4d..6e679d23d 100644
--- a/src/lib/exchange_api_refreshes_reveal.c
+++ b/src/lib/exchange_api_refreshes_reveal.c
@@ -167,6 +167,7 @@ refresh_reveal_ok (struct TALER_EXCHANGE_RefreshesRevealHandle *rrh,
     GNUNET_CRYPTO_eddsa_key_get_public (&fc->coin_priv.eddsa_priv,
                                         &coin_pub.eddsa_pub);
     TALER_coin_pub_hash (&coin_pub,
+                         /* FIXME-Oec: Age commitment hash */
                          &coin_hash);
     if (GNUNET_OK !=
         TALER_planchet_to_coin (pk,
diff --git a/src/pq/pq_query_helper.c b/src/pq/pq_query_helper.c
index 618877608..43b8374a2 100644
--- a/src/pq/pq_query_helper.c
+++ b/src/pq/pq_query_helper.c
@@ -185,7 +185,7 @@ qconv_denom_pub (void *cls,
   GNUNET_assert (scratch_length > 0);
   GNUNET_break (NULL == cls);
   be[0] = htonl ((uint32_t) denom_pub->cipher);
-  be[1] = htonl (denom_pub->age_mask);
+  be[1] = htonl (denom_pub->age_mask.mask);
   switch (denom_pub->cipher)
   {
   case TALER_DENOMINATION_RSA:
diff --git a/src/pq/pq_result_helper.c b/src/pq/pq_result_helper.c
index 2f570b6bb..ea815a9c2 100644
--- a/src/pq/pq_result_helper.c
+++ b/src/pq/pq_result_helper.c
@@ -551,7 +551,7 @@ extract_denom_pub (void *cls,
   res += sizeof (be);
   len -= sizeof (be);
   pk->cipher = ntohl (be[0]);
-  pk->age_mask = ntohl (be[1]);
+  pk->age_mask.mask = ntohl (be[1]);
   switch (pk->cipher)
   {
   case TALER_DENOMINATION_RSA:
diff --git a/src/util/Makefile.am b/src/util/Makefile.am
index 556c3b6f3..3c9a72646 100644
--- a/src/util/Makefile.am
+++ b/src/util/Makefile.am
@@ -71,6 +71,7 @@ libtalerutil_la_SOURCES = \
   crypto_wire.c \
   denom.c \
   exchange_signatures.c \
+  extension_age_restriction.c \
   getopt.c \
   lang.c \
   iban.c \
diff --git a/src/util/crypto.c b/src/util/crypto.c
index 2c81554b9..67cf14b42 100644
--- a/src/util/crypto.c
+++ b/src/util/crypto.c
@@ -320,6 +320,7 @@ void
 TALER_coin_pub_hash (const struct TALER_CoinSpendPublicKeyP *coin_pub,
                      struct TALER_CoinPubHash *coin_h)
 {
+  // FIXME-Oec: hash over age-restriction, too
   GNUNET_CRYPTO_hash (&coin_pub->eddsa_pub,
                       sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey),
                       &coin_h->hash);
diff --git a/src/util/crypto_helper_denom.c b/src/util/crypto_helper_denom.c
index 4dfd32fbd..e1cd2b6ba 100644
--- a/src/util/crypto_helper_denom.c
+++ b/src/util/crypto_helper_denom.c
@@ -20,6 +20,7 @@
  */
 #include "platform.h"
 #include "taler_util.h"
+#include "taler_extensions.h"
 #include "taler_signatures.h"
 #include "taler-exchange-secmod-rsa.h"
 #include <poll.h>
@@ -62,6 +63,11 @@ struct TALER_CRYPTO_DenominationHelper
    * Have we ever been sync'ed?
    */
   bool synced;
+
+  /**
+   * Age Mask that applies to this denomination.
+   */
+  struct TALER_AgeMask age_mask;
 };
 
 
@@ -273,6 +279,19 @@ TALER_CRYPTO_helper_denom_connect (
       TALER_CRYPTO_helper_denom_disconnect (dh);
       return NULL;
     }
+
+    /* Extract the age groups from the config, if the extension has been set,
+     * and serialize them into the age mask */
+    if (GNUNET_OK !=
+        TALER_get_age_mask (cfg, &dh->age_mask))
+    {
+      GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
+                                 "extensions", /* FIXME: right section etc? */
+                                 "age-restriction",
+                                 "invalid age groups");
+      TALER_CRYPTO_helper_denom_disconnect (dh);
+      return NULL;
+    }
   }
   TALER_CRYPTO_helper_denom_poll (dh);
   return dh;
@@ -320,7 +339,7 @@ handle_mt_avail (struct TALER_CRYPTO_DenominationHelper *dh,
     struct TALER_DenominationHash h_denom_pub;
 
     denom_pub.cipher = TALER_DENOMINATION_RSA;
-    denom_pub.age_mask = 0; // FIXME-Oec!
+    denom_pub.age_mask = dh->age_mask;
     denom_pub.details.rsa_public_key
       = GNUNET_CRYPTO_rsa_public_key_decode (buf,
                                              ntohs (kan->pub_size));
diff --git a/src/util/denom.c b/src/util/denom.c
index cdcfc5c3a..a5305343b 100644
--- a/src/util/denom.c
+++ b/src/util/denom.c
@@ -161,7 +161,7 @@ TALER_denom_pub_hash (const struct TALER_DenominationPublicKey *denom_pub,
                       struct TALER_DenominationHash *denom_hash)
 {
   uint32_t opt[2] = {
-    htonl (denom_pub->age_mask),
+    htonl (denom_pub->age_mask.mask),
     htonl ((uint32_t) denom_pub->cipher)
   };
 
@@ -197,7 +197,7 @@ TALER_denom_pub_hash (const struct TALER_DenominationPublicKey *denom_pub,
 
 void
 TALER_denom_priv_to_pub (const struct TALER_DenominationPrivateKey *denom_priv,
-                         uint32_t age_mask,
+                         const struct TALER_AgeMask age_mask,
                          struct TALER_DenominationPublicKey *denom_pub)
 {
   switch (denom_priv->cipher)
@@ -446,8 +446,8 @@ TALER_denom_pub_cmp (const struct TALER_DenominationPublicKey *denom1,
 {
   if (denom1->cipher != denom2->cipher)
     return (denom1->cipher > denom2->cipher) ? 1 : -1;
-  if (denom1->age_mask != denom2->age_mask)
-    return (denom1->age_mask > denom2->age_mask) ? 1 : -1;
+  if (denom1->age_mask.mask != denom2->age_mask.mask)
+    return (denom1->age_mask.mask > denom2->age_mask.mask) ? 1 : -1;
   switch (denom1->cipher)
   {
   case TALER_DENOMINATION_INVALID:
diff --git a/src/util/extension_age_restriction.c b/src/util/extension_age_restriction.c
new file mode 100644
index 000000000..64ecaa31e
--- /dev/null
+++ b/src/util/extension_age_restriction.c
@@ -0,0 +1,49 @@
+/*
+  This file is part of TALER
+  Copyright (C) 2014-2020 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 extension_age_restriction.c
+ * @brief Utility functions regarding age restriction
+ * @author Özgür Kesim
+ */
+#include "platform.h"
+#include "taler_util.h"
+
+
+/**
+ *
+ * @param cfg
+ * @param[out] mask for age restriction
+ * @return Error if extension for age restriction was set but age groups were
+ *         invalid, OK otherwise.
+ */
+enum GNUNET_GenericReturnValue
+TALER_get_age_mask (const struct GNUNET_CONFIGURATION_Handle *cfg, struct
+                    TALER_AgeMask *mask)
+{
+  /* FIXME-Oec:
+   *
+   * - Detect if age restriction is enabled in config
+   * - if not, return 0 mask
+   * - else, parse age group and serialize into mask
+   * - return Error on
+   *
+   * */
+  mask->mask = 0;
+  return GNUNET_OK;
+}
+
+
+/* end of extension_age_restriction.c */
diff --git a/src/util/taler-exchange-secmod-rsa.c b/src/util/taler-exchange-secmod-rsa.c
index 1248b126d..e996f14ee 100644
--- a/src/util/taler-exchange-secmod-rsa.c
+++ b/src/util/taler-exchange-secmod-rsa.c
@@ -1422,9 +1422,10 @@ parse_key (struct Denomination *denom,
     struct TALER_DenominationPublicKey pub;
     struct DenominationKey *dk;
     struct DenominationKey *before;
+    struct TALER_AgeMask age_mask = { .mask = 0 }; /* FIXME-Oec */
 
     TALER_denom_priv_to_pub (&priv,
-                             0 /* FIXME-Oec */,
+                             age_mask,
                              &pub);
     dk = GNUNET_new (struct DenominationKey);
     dk->denom_priv = priv;