Changing configuration structure to enable multiple accounts.

This change enables using multiple wire plugins at the same time.
Also, we now distinguish between the wire plugin (i.e. EBICS or
taler_bank) and the wire method (i.e. SEPA or x-taler-bank) that
the wire plugin is implementing.  The "taler-bank" wire method
was renamed from "test" to "x-taler-bank".

This also changes the format of the /wire response of the exchange,
as we now need to return multiple accounts.  Note that wire fees
are specified per wire method, not per wire account.

taler-exchange-keyup now automatically signs all of the /wire
responses in the location specified by the configuration.

Account identification in wire plugins was changed to use
payto://-URLs instead of method-specific JSON fields.  Signing
and validation of /wire responses was moved from each wire
plugin to a generic validation method in libtalerutil (crypto)
or libtalerjson (for JSON-formatted inputs).
Convenience methods were added to generate JSON for wire accounts
(salting, signing).

Various section and option names were adjusted to streamline the
configuration and make it more consistent overall.  Documentation
was updated as well.

1 files changed, 28 insertions, 47 deletions

diff --git a/src/include/taler_wire_plugin.h b/src/include/taler_wire_plugin.h
index c0e29609f..2758d2d2e 100644
--- a/src/include/taler_wire_plugin.h
+++ b/src/include/taler_wire_plugin.h
@@ -22,7 +22,6 @@
 #define TALER_WIRE_PLUGIN_H
 
 #include <gnunet/gnunet_util_lib.h>
-#include <jansson.h>
 #include "taler_util.h"
 #include "taler_error_codes.h"
 #include "taler_bank_service.h" /* for `enum TALER_BANK_Direction` and `struct TALER_BANK_TransferDetails` */
@@ -72,9 +71,9 @@ struct TALER_WIRE_TransferDetails
   char *wtid_s;
 
   /**
-   * The other account that was involved
+   * payto://-URL of the other account that was involved
    */
-  json_t *account_details;
+  char *account_url;
 };
 
 
@@ -161,6 +160,13 @@ struct TALER_WIRE_Plugin
   char *library_name;
 
   /**
+   * Which wire method (payto://METHOD/") is supported by this plugin?
+   * For example, "sepa" or "x-taler-bank".
+   */
+  const char *method;
+
+
+  /**
    * Round amount DOWN to the amount that can be transferred via the wire
    * method.  For example, Taler may support 0.000001 EUR as a unit of
    * payment, but SEPA only supports 0.01 EUR.  This function would
@@ -177,62 +183,27 @@ struct TALER_WIRE_Plugin
 
 
   /**
-   * Obtain wire transfer details in the plugin-specific format
-   * from the configuration.
-   *
-   * @param cls closure
-   * @param cfg configuration with details about wire accounts
-   * @param account_name which section in the configuration should we parse
-   * @return NULL if @a cfg fails to have valid wire details for @a account_name
-   */
-  json_t *
-  (*get_wire_details)(void *cls,
-                      const struct GNUNET_CONFIGURATION_Handle *cfg,
-                      const char *account_name);
-
-
-  /**
-   * Sign wire transfer details in the plugin-specific format.
-   *
-   * @param cls closure
-   * @param in wire transfer details in JSON format
-   * @param key private signing key to use
-   * @param salt salt to add
-   * @param[out] sig where to write the signature
-   * @return #GNUNET_OK on success
-   */
-  int
-  (*sign_wire_details)(void *cls,
-                       const json_t *in,
-                       const struct TALER_MasterPrivateKeyP *key,
-                       const struct GNUNET_HashCode *salt,
-                       struct TALER_MasterSignatureP *sig);
-
-
-  /**
-   * Check if the given wire format JSON object is correctly formatted
+   * Check if the given payto:// URL is correctly formatted for this plugin
    *
    * @param cls the @e cls of this struct with the plugin-specific state
-   * @param wire the JSON wire format object
-   * @param master_pub public key of the exchange to verify against
-   * @param[out] emsg set to an error message, unless we return #TALER_EC_NONE;
-   *             error message must be freed by the caller using GNUNET_free()
+   * @param account_url the payto:// URL
    * @return #TALER_EC_NONE if correctly formatted
    */
   enum TALER_ErrorCode
   (*wire_validate) (void *cls,
-                    const json_t *wire,
-                    const struct TALER_MasterPublicKeyP *master_pub,
-                    char **emsg);
+                    const char *account_url);
 
 
   /**
    * Prepare for exeuction of a wire transfer.
    *
    * @param cls the @e cls of this struct with the plugin-specific state
-   * @param wire valid wire account information
+   * @param origin_account_section configuration section specifying the origin
+   *        account of the exchange to use
+   * @param destination_account_url payto:// URL identifying where to send the money
    * @param amount amount to transfer, already rounded
-   * @param exchange_base_url base URL of this exchange
+   * @param exchange_base_url base URL of this exchange (included in subject
+   *        to facilitate use of tracking API by merchant backend)
    * @param wtid wire transfer identifier to use
    * @param ptc function to call with the prepared data to persist
    * @param ptc_cls closure for @a ptc
@@ -240,13 +211,15 @@ struct TALER_WIRE_Plugin
    */
   struct TALER_WIRE_PrepareHandle *
   (*prepare_wire_transfer) (void *cls,
-                            const json_t *wire,
+                            const char *origin_account_section,
+                            const char *destination_account_url,
                             const struct TALER_Amount *amount,
                             const char *exchange_base_url,
                             const struct TALER_WireTransferIdentifierRawP *wtid,
                             TALER_WIRE_PrepareTransactionCallback ptc,
                             void *ptc_cls);
 
+
   /**
    * Abort preparation of a wire transfer. For example,
    * because we are shutting down.
@@ -305,6 +278,8 @@ struct TALER_WIRE_Plugin
    * (with negative @a num_results).
    *
    * @param cls the @e cls of this struct with the plugin-specific state
+   * @param account_section specifies the configuration section which
+   *        identifies the account for which we should get the history
    * @param direction what kinds of wire transfers should be returned
    * @param start_off from which row on do we want to get results, use NULL for the latest; exclusive
    * @param start_off_len number of bytes in @a start_off
@@ -316,6 +291,7 @@ struct TALER_WIRE_Plugin
    */
   struct TALER_WIRE_HistoryHandle *
   (*get_history) (void *cls,
+                  const char *account_section,
                   enum TALER_BANK_Direction direction,
                   const void *start_off,
                   size_t start_off_len,
@@ -323,6 +299,7 @@ struct TALER_WIRE_Plugin
                   TALER_WIRE_HistoryResultCallback hres_cb,
                   void *hres_cb_cls);
 
+
   /**
    * Cancel going over the account's history.
    *
@@ -345,6 +322,8 @@ struct TALER_WIRE_Plugin
    * results returned by @e get_history.
    *
    * @param cls plugin's closure
+   * @param account_section specifies the configuration section which
+   *        identifies the account to use to reject the transfer
    * @param start_off offset of the wire transfer in plugin-specific format
    * @param start_off_len number of bytes in @a start_off
    * @param rej_cb function to call with the result of the operation
@@ -353,11 +332,13 @@ struct TALER_WIRE_Plugin
    */
   struct TALER_WIRE_RejectHandle *
   (*reject_transfer)(void *cls,
+                     const char *account_section,
                      const void *start_off,
                      size_t start_off_len,
                      TALER_WIRE_RejectTransferCallback rej_cb,
                      void *rej_cb_cls);
 
+
   /**
    * Cancel ongoing reject operation.  Note that the rejection may still
    * proceed. Basically, if this function is called, the rejection may