implementing retrieval of auditor information from /keys in mint API (with updated specification) - #3847

2 files changed, 96 insertions, 8 deletions

diff --git a/src/include/taler_mint_service.h b/src/include/taler_mint_service.h
index 3f89b0745..8d569d4bc 100644
--- a/src/include/taler_mint_service.h
+++ b/src/include/taler_mint_service.h
@@ -150,6 +150,11 @@ struct TALER_MINT_DenomPublicKey
   struct TALER_DenominationPublicKey key;
 
   /**
+   * The hash of the public key.
+   */
+  struct GNUNET_HashCode h_key;
+
+  /**
    * Timestamp indicating when the denomination key becomes valid
    */
   struct GNUNET_TIME_Absolute valid_from;
@@ -166,6 +171,15 @@ struct TALER_MINT_DenomPublicKey
   struct GNUNET_TIME_Absolute deposit_valid_until;
 
   /**
+   * When do signatures with this denomination key become invalid?
+   * After this point, these signatures cannot be used in (legal)
+   * disputes anymore, as the Mint is then allowed to destroy its side
+   * of the evidence.  @e expire_legal is expected to be significantly
+   * larger than @e expire_spend (by a year or more).
+   */
+  struct GNUNET_TIME_Absolute expire_legal;
+
+  /**
    * The value of this denomination
    */
   struct TALER_Amount value;
@@ -204,6 +218,8 @@ struct TALER_MINT_AuditorInformation
    * that website.  We expect that in practice software is going to
    * often ship with an initial list of accepted auditors, just like
    * browsers ship with a CA root store.
+   *
+   * This field may be NULL. (#3987).
    */
   const char *auditor_url;
 
@@ -218,7 +234,7 @@ struct TALER_MINT_AuditorInformation
    * elements point to the same locations as the entries
    * in the key's main `denom_keys` array.
    */
-  struct TALER_MINT_DenomPublicKey *const*denom_keys;
+  const struct TALER_MINT_DenomPublicKey **denom_keys;
 };
 
 
@@ -246,7 +262,7 @@ struct TALER_MINT_Keys
   /**
    * Array of the keys of the auditors of the mint.
    */
-  struct TALER_AuditorPublicKeyP *auditors;
+  struct TALER_MINT_AuditorInformation *auditors;
 
   /**
    * Length of the @e sign_keys array.
@@ -353,6 +369,18 @@ TALER_MINT_get_denomination_key (const struct TALER_MINT_Keys *keys,
                                  const struct TALER_DenominationPublicKey *pk);
 
 
+/**
+ * Obtain the denomination key details from the mint.
+ *
+ * @param keys the mint's key set
+ * @param hc hash of the public key of the denomination to lookup
+ * @return details about the given denomination key
+ */
+const struct TALER_MINT_DenomPublicKey *
+TALER_MINT_get_denomination_key_by_hash (const struct TALER_MINT_Keys *keys,
+                                         const struct GNUNET_HashCode *hc);
+
+
 /* *********************  /wire *********************** */
 
 
diff --git a/src/include/taler_signatures.h b/src/include/taler_signatures.h
index ffbc9fd45..3bdc4eee1 100644
--- a/src/include/taler_signatures.h
+++ b/src/include/taler_signatures.h
@@ -653,13 +653,73 @@ struct TALER_MintKeyValidityPS
   struct TALER_MasterPublicKeyP master;
 
   /**
-   * Array of hash(es) of the mint's denomination keys.
-   * Specifically, this is the hash over the
-   * `struct TALER_DenominationKeyValidityPS`, not just
-   * the public key (as the auditor needs to check against
-   * the correct valuations and fee structure).
+   * Start time of the validity period for this key.
+   */
+  struct GNUNET_TIME_AbsoluteNBO start;
+
+  /**
+   * The mint will sign fresh coins between @e start and this time.
+   * @e expire_withdraw will be somewhat larger than @e start to
+   * ensure a sufficiently large anonymity set, while also allowing
+   * the Mint to limit the financial damage in case of a key being
+   * compromised.  Thus, mints with low volume are expected to have a
+   * longer withdraw period (@e expire_withdraw - @e start) than mints
+   * with high transaction volume.  The period may also differ between
+   * types of coins.  A mint may also have a few denomination keys
+   * with the same value with overlapping validity periods, to address
+   * issues such as clock skew.
+   */
+  struct GNUNET_TIME_AbsoluteNBO expire_withdraw;
+
+  /**
+   * Coins signed with the denomination key must be spent or refreshed
+   * between @e start and this expiration time.  After this time, the
+   * mint will refuse transactions involving this key as it will
+   * "drop" the table with double-spending information (shortly after)
+   * this time.  Note that wallets should refresh coins significantly
+   * before this time to be on the safe side.  @e expire_spend must be
+   * significantly larger than @e expire_withdraw (by months or even
+   * years).
+   */
+  struct GNUNET_TIME_AbsoluteNBO expire_spend;
+
+  /**
+   * When do signatures with this denomination key become invalid?
+   * After this point, these signatures cannot be used in (legal)
+   * disputes anymore, as the Mint is then allowed to destroy its side
+   * of the evidence.  @e expire_legal is expected to be significantly
+   * larger than @e expire_spend (by a year or more).
    */
-  /* struct GNUNET_HashCode h_dks; */
+  struct GNUNET_TIME_AbsoluteNBO expire_legal;
+
+  /**
+   * The value of the coins signed with this denomination key.
+   */
+  struct TALER_AmountNBO value;
+
+  /**
+   * The fee the mint charges when a coin of this type is withdrawn.
+   * (can be zero).
+   */
+  struct TALER_AmountNBO fee_withdraw;
+
+  /**
+   * The fee the mint charges when a coin of this type is deposited.
+   * (can be zero).
+   */
+  struct TALER_AmountNBO fee_deposit;
+
+  /**
+   * The fee the mint charges when a coin of this type is refreshed.
+   * (can be zero).
+   */
+  struct TALER_AmountNBO fee_refresh;
+
+  /**
+   * Hash code of the denomination public key. (Used to avoid having
+   * the variable-size RSA key in this struct.)
+   */
+  struct GNUNET_HashCode denom_hash GNUNET_PACKED;
 
 };