[age restriction] progress 14/n - withdraw and deposit

Age restriction support for
  - withdraw is done and tested
  - deposit is done and tested

TODOs:
  - melt/refresh/reveal
  - link

------

Added functions
 - TALER_age_restriction_commit
 - TALER_age_commitment_derive
 - TALER_age_commitment_hash
 - TALER_age_restriction_commitment_free_inside
 - Hash of age commitment passed around API boundaries

Exchangedb adjustments for denominations
 - all prepared statements re: denominations now handle age_mask
 - signature parameters adjusted

Hash and signature verification of /keys adjusted
 - Hashes of (normal) denominations and age-restricted denominations are
   calculated seperately
 - The hash of the age-restricted ones will then be added to the other
   hash
 - The total hash is signed/verified

Tests for withdraw with age restriction added
 - TALER_EXCHANGE_DenomPublickey now carries age_mask
 - TALER_TESTING_cmd_withdraw_amount* takes age parameter
 - TALER_TESTING_find_pk takes boolean age_restricted
 - WithdrawState carries age_commitment and its hash
 - withdraw_run derives new age commitment, if applicable
 - Added age parameter to testing (13 as example)

Various Fixes and changes
 - Fixes of post handler for /management/extensions
 - Fixes for offline tool extensions signing
 - Slight refactoring of extensions
 - Age restriction extension simplified
   - config is now global to extension
   - added global TEH_age_restriction_enabled and TEH_age_mask in
     taler-exchange-httpd
   - helper functions and macros introduced

1 files changed, 10 insertions, 0 deletions

diff --git a/src/lib/exchange_api_withdraw.c b/src/lib/exchange_api_withdraw.c
index c832699a2..efc8a99c2 100644
--- a/src/lib/exchange_api_withdraw.c
+++ b/src/lib/exchange_api_withdraw.c
@@ -89,6 +89,11 @@ struct TALER_EXCHANGE_WithdrawHandle
   struct TALER_ExchangeWithdrawValues alg_values;
 
   /**
+   * Hash of the age commitment for this coin, if applicable. Maybe NULL
+   */
+  const struct TALER_AgeCommitmentHash *ach;
+
+  /**
    * Denomination key we are withdrawing.
    */
   struct TALER_EXCHANGE_DenomPublicKey pk;
@@ -137,6 +142,7 @@ handle_reserve_withdraw_finished (
                                   blind_sig,
                                   &wh->bks,
                                   &wh->priv,
+                                  wh->ach,
                                   &wh->c_hash,
                                   &wh->alg_values,
                                   &fc))
@@ -222,6 +228,7 @@ withdraw_cs_stage_two_callback (void *cls,
                                 &wh->alg_values,
                                 &wh->bks,
                                 &wh->priv,
+                                wh->ach,
                                 &wh->c_hash,
                                 &wh->pd))
     {
@@ -249,6 +256,7 @@ TALER_EXCHANGE_withdraw (
   const struct TALER_EXCHANGE_DenomPublicKey *pk,
   const struct TALER_ReservePrivateKeyP *reserve_priv,
   const struct TALER_PlanchetMasterSecretP *ps,
+  const struct TALER_AgeCommitmentHash *ach,
   TALER_EXCHANGE_WithdrawCallback res_cb,
   void *res_cb_cls)
 {
@@ -260,6 +268,7 @@ TALER_EXCHANGE_withdraw (
   wh->cb_cls = res_cb_cls;
   wh->reserve_priv = reserve_priv;
   wh->ps = *ps;
+  wh->ach = ach;
   wh->pk = *pk;
   TALER_denom_pub_deep_copy (&wh->pk.key,
                              &pk->key);
@@ -280,6 +289,7 @@ TALER_EXCHANGE_withdraw (
                                   &wh->alg_values,
                                   &wh->bks,
                                   &wh->priv,
+                                  wh->ach,
                                   &wh->c_hash,
                                   &wh->pd))
       {