extend merchant lib to allow tokens as inputs

2 files changed, 138 insertions, 1 deletions

diff --git a/src/include/taler_merchant_service.h b/src/include/taler_merchant_service.h
index 057c9eff..180df516 100644
--- a/src/include/taler_merchant_service.h
+++ b/src/include/taler_merchant_service.h
@@ -3201,6 +3201,38 @@ struct TALER_MERCHANT_PaidCoin
 
 
 /**
+ * Information the frontend forwards to the backend to use a token for
+ * an order. Note that this does not include the token use private key,
+ * but only public keys and signatures.
+ */
+struct TALER_MERCHANT_UsedToken
+{
+
+  /**
+   * Signature on TALER_TokenUseRequestPS made with the token use private key.
+   */
+  struct TALER_TokenUseSignatureP token_sig;
+
+  /**
+   * Public key of the token. This was blindly signed by the merchant
+   * during the issuance and is now being revealed to the merchant.
+   */
+  struct TALER_TokenUsePublicKeyP token_pub;
+
+  /**
+   * Unblinded signature made by the token issue public key of the merchant.
+   */
+  struct TALER_TokenIssueSignatureP ub_sig;
+
+  /**
+   * Token issue public key associated with this token.
+   */
+  struct TALER_TokenIssuePublicKeyP issue_pub;
+
+};
+
+
+/**
  * Pay a merchant.  API for frontends talking to backends. Here,
  * the frontend does not have the coin's private keys, but just
  * the public keys and signatures.
@@ -3215,6 +3247,8 @@ struct TALER_MERCHANT_PaidCoin
  * @param wallet_data inputs from the wallet for the contract, NULL for none
  * @param num_coins length of the @a coins array
  * @param coins array of coins to pay with
+ * @param num_tokens length of the @a tokens array
+ * @param tokens array of tokens used
  * @param pay_cb the callback to call when a reply for this request is available
  * @param pay_cb_cls closure for @a pay_cb
  * @return a handle for this request
@@ -3228,6 +3262,8 @@ TALER_MERCHANT_order_pay_frontend (
   const json_t *wallet_data,
   unsigned int num_coins,
   const struct TALER_MERCHANT_PaidCoin coins[static num_coins],
+  unsigned int num_tokens,
+  const struct TALER_MERCHANT_UsedToken tokens[static num_tokens],
   TALER_MERCHANT_OrderPayCallback pay_cb,
   void *pay_cb_cls);
 
@@ -3282,6 +3318,30 @@ struct TALER_MERCHANT_PayCoin
 
 
 /**
+ * Information we need from the wallet to use a token for an order.
+ */
+struct TALER_MERCHANT_UseToken
+{
+
+  /**
+   * Token use private key. We will derive the public key from this.
+   */
+  struct TALER_TokenUsePrivateKeyP token_priv;
+
+  /**
+   * Unblinded signature made by the token issue public key of the merchant.
+   */
+  struct TALER_TokenIssueSignatureP ub_sig;
+
+  /**
+   * Token issue public key associated with this token.
+   */
+  struct TALER_TokenIssuePublicKeyP issue_pub;
+
+};
+
+
+/**
  * Pay a merchant.  API for wallets that have the coin's private keys.
  *
  * This is a PUBLIC API for wallets.
@@ -3302,6 +3362,8 @@ struct TALER_MERCHANT_PayCoin
  * @param order_id order id
  * @param num_coins number of coins used to pay
  * @param coins array of coins we use to pay
+ * @param num_tokens number of tokens to used in this payment request
+ * @param tokens array of tokens we use in this payment request
  * @param pay_cb the callback to call when a reply for this request is available
  * @param pay_cb_cls closure for @a pay_cb
  * @return a handle for this request
@@ -3324,6 +3386,8 @@ TALER_MERCHANT_order_pay (
   const char *order_id,
   unsigned int num_coins,
   const struct TALER_MERCHANT_PayCoin coins[static num_coins],
+  unsigned int num_tokens,
+  const struct TALER_MERCHANT_UseToken tokens[static num_tokens],
   TALER_MERCHANT_OrderPayCallback pay_cb,
   void *pay_cb_cls);
 
diff --git a/src/lib/merchant_api_post_order_pay.c b/src/lib/merchant_api_post_order_pay.c
index 57c85565..e56bac60 100644
--- a/src/lib/merchant_api_post_order_pay.c
+++ b/src/lib/merchant_api_post_order_pay.c
@@ -80,6 +80,11 @@ struct TALER_MERCHANT_OrderPayHandle
   struct TALER_MERCHANT_PaidCoin *coins;
 
   /**
+   * The tokens we are using.
+   */
+  struct TALER_MERCHANT_UsedToken *tokens;
+
+  /**
    * Hash of the contract we are paying, set
    * if @e am_wallet is true.
    */
@@ -114,6 +119,11 @@ struct TALER_MERCHANT_OrderPayHandle
   unsigned int num_coins;
 
   /**
+   * Number of @e tokens we are using.
+   */
+  unsigned int num_tokens;
+
+  /**
    * Set to true if this is the wallet API and we have
    * initialized @e h_contract_terms and @e merchant_pub.
    */
@@ -308,12 +318,15 @@ TALER_MERCHANT_order_pay_frontend (
   const json_t *wallet_data,
   unsigned int num_coins,
   const struct TALER_MERCHANT_PaidCoin coins[static num_coins],
+  unsigned int num_tokens,
+  const struct TALER_MERCHANT_UsedToken tokens[static num_tokens],
   TALER_MERCHANT_OrderPayCallback pay_cb,
   void *pay_cb_cls)
 {
   struct TALER_MERCHANT_OrderPayHandle *oph;
   json_t *pay_obj;
   json_t *j_coins;
+  json_t *j_tokens = NULL;
   CURL *eh;
   struct TALER_Amount total_fee;
   struct TALER_Amount total_amount;
@@ -392,10 +405,43 @@ TALER_MERCHANT_order_pay_frontend (
     }
   }
 
+  if (0 < num_tokens)
+  {
+    j_tokens = json_array ();
+    GNUNET_assert (NULL != j_tokens);
+    for (unsigned int i = 0; i<num_tokens; i++)
+    {
+      json_t *j_token;
+      const struct TALER_MERCHANT_UsedToken *ut = &tokens[i];
+
+      j_token = GNUNET_JSON_PACK (
+        GNUNET_JSON_pack_data_auto ("token_sig",
+                                    &ut->token_sig),
+        GNUNET_JSON_pack_data_auto ("token_pub",
+                                    &ut->token_pub),
+        TALER_JSON_pack_token_issue_sig ("ub_sig",
+                                        &ut->ub_sig),
+        /* TODO: Check if we need a more specific hash, similar to TALER_denom_pub_hash () */
+        GNUNET_JSON_pack_data_auto ("h_issue",
+                                    &ut->issue_pub.public_key->pub_key_hash));
+      if (0 !=
+          json_array_append_new (j_tokens,
+                                j_token))
+      {
+        GNUNET_break (0);
+        json_decref (j_tokens);
+        return NULL;
+      }
+    }
+  }
+
   pay_obj = GNUNET_JSON_PACK (
     GNUNET_JSON_pack_array_steal ("coins",
                                   j_coins),
     GNUNET_JSON_pack_allow_null (
+      GNUNET_JSON_pack_array_steal ("tokens",
+                                    j_tokens)),
+    GNUNET_JSON_pack_allow_null (
       GNUNET_JSON_pack_object_incref ("wallet_data",
                                       (json_t *) wallet_data)),
     GNUNET_JSON_pack_allow_null (
@@ -473,11 +519,13 @@ TALER_MERCHANT_order_pay (
   const char *order_id,
   unsigned int num_coins,
   const struct TALER_MERCHANT_PayCoin coins[static num_coins],
+  unsigned int num_tokens,
+  const struct TALER_MERCHANT_UseToken tokens[static num_tokens],
   TALER_MERCHANT_OrderPayCallback pay_cb,
   void *pay_cb_cls)
 {
   struct GNUNET_HashCode wallet_data_hash;
-  
+
   if (GNUNET_YES !=
       TALER_amount_cmp_currency (amount,
                                  max_fee))
@@ -485,11 +533,20 @@ TALER_MERCHANT_order_pay (
     GNUNET_break (0);
     return NULL;
   }
+  if (0 < num_tokens && NULL == wallet_data)
+  {
+    /* Since the wallet has to sign over the wallet_data_hash
+       to use tokens, wallet data must not be NULL if input
+       tokens are provided */
+    GNUNET_break (0);
+    return NULL;
+  }
   if (NULL != wallet_data)
     TALER_json_hash (wallet_data,
                      &wallet_data_hash);
   {
     struct TALER_MERCHANT_PaidCoin pc[num_coins];
+    struct TALER_MERCHANT_UsedToken ut[num_tokens];
 
     for (unsigned int i = 0; i<num_coins; i++)
     {
@@ -534,6 +591,20 @@ TALER_MERCHANT_order_pay (
       p->amount_without_fee = coin->amount_without_fee;
       p->exchange_url = coin->exchange_url;
     }
+    for (unsigned int i = 0; i<num_tokens; i++)
+    {
+      const struct TALER_MERCHANT_UseToken *token = &tokens[i];
+      struct TALER_MERCHANT_UsedToken *t = &ut[i];
+
+      TALER_wallet_token_use_sign (h_contract_terms,
+                                   &wallet_data_hash, // checked for != NULL above
+                                   &token->token_priv,
+                                   &t->token_sig);
+      t->ub_sig = token->ub_sig;
+      t->issue_pub = token->issue_pub;
+      GNUNET_CRYPTO_eddsa_key_get_public (&token->token_priv.private_key,
+                                          &t->token_pub.public_key);
+    }
     {
       struct TALER_MERCHANT_OrderPayHandle *oph;
 
@@ -544,6 +615,8 @@ TALER_MERCHANT_order_pay (
                                                wallet_data,
                                                num_coins,
                                                pc,
+                                               num_tokens,
+                                               ut,
                                                pay_cb,
                                                pay_cb_cls);
       if (NULL == oph)