revise P2P signatures and signing schema to address recently discovered design concern resulting in the split of the purse key into purse-contract and purse-merge keys

5 files changed, 300 insertions, 119 deletions

diff --git a/src/exchangedb/drop0001.sql b/src/exchangedb/drop0001.sql
index 49d9d3639..c969286a0 100644
--- a/src/exchangedb/drop0001.sql
+++ b/src/exchangedb/drop0001.sql
@@ -79,6 +79,11 @@ DROP TABLE IF EXISTS denominations CASCADE;
 DROP TABLE IF EXISTS cs_nonce_locks CASCADE;
 DROP FUNCTION IF EXISTS add_constraints_to_cs_nonce_locks_partition;
 
+DROP TABLE IF EXISTS deposits_by_coin CASCADE;
+DROP TABLE IF EXISTS global_fee CASCADE;
+DROP TABLE IF EXISTS recoup_by_reserve CASCADE;
+
+
 DROP TABLE IF EXISTS partners CASCADE;
 DROP TABLE IF EXISTS mergers CASCADE;
 DROP TABLE IF EXISTS contracts CASCADE;
diff --git a/src/exchangedb/exchange-0001.sql b/src/exchangedb/exchange-0001.sql
index a12789c5e..5a4199040 100644
--- a/src/exchangedb/exchange-0001.sql
+++ b/src/exchangedb/exchange-0001.sql
@@ -1403,45 +1403,85 @@ COMMENT ON COLUMN partners.partner_base_url
 COMMENT ON COLUMN partners.master_sig
   IS 'signature of our master public key affirming the partnership, of purpose TALER_SIGNATURE_MASTER_PARTNER_DETAILS';
 
-CREATE TABLE IF NOT EXISTS mergers
-  (merge_request_serial_id BIGSERIAL UNIQUE
-  ,partner_serial_id INT8 REFERENCES partners(partner_serial_id) ON DELETE CASCADE
-  ,reserve_pub BYTEA NOT NULL REFERENCES reserves (reserve_pub) ON DELETE CASCADE
-  ,reserve_sig BYTEA NOT NULL CHECK (LENGTH(reserve_sig)=64)
+
+CREATE TABLE IF NOT EXISTS purse_requests
+  (purse_deposit_serial_id BIGSERIAL UNIQUE
   ,purse_pub BYTEA NOT NULL CHECK (LENGTH(purse_pub)=32)
-  ,purse_sig BYTEA NOT NULL CHECK (LENGTH(purse_sig)=64)
-  ,merge_timestamp INT8 NOT NULL
+  ,merge_pub BYTEA NOT NULL CHECK (LENGTH(merge_pub)=32)
   ,purse_expiration INT8 NOT NULL
   ,h_contract_terms BYTEA NOT NULL CHECK (LENGTH(h_contract_terms)=64)
-  ,purse_val INT8 NOT NULL
-  ,purse_frac INT4 NOT NULL
+  ,amount_with_fee_val INT8 NOT NULL
+  ,amount_with_fee_frac INT4 NOT NULL
+  ,balance_val INT8 NOT NULL
+  ,balance_frac INT4 NOT NULL
+  ,purse_sig BYTEA NOT NULL CHECK(LENGTH(purse_sig)=64)
+  ,PRIMARY KEY (purse_pub)
+  ); -- partition by purse_pub
+COMMENT ON TABLE purse_requests
+  IS 'Requests establishing purses, associating them with a contract but without a target reserve';
+COMMENT ON COLUMN purse_requests.purse_pub
+  IS 'Public key of the purse';
+COMMENT ON COLUMN purse_requests.purse_expiration
+  IS 'When the purse is set to expire';
+COMMENT ON COLUMN purse_requests.h_contract_terms
+  IS 'Hash of the contract the parties are to agree to';
+COMMENT ON COLUMN purse_requests.amount_with_fee_val
+  IS 'Total amount expected to be in the purse';
+COMMENT ON COLUMN purse_requests.balance_val
+  IS 'Total amount actually in the purse';
+COMMENT ON COLUMN purse_requests.purse_sig
+  IS 'Signature of the purse affirming the purse parameters, of type TALER_SIGNATURE_PURSE_REQUEST';
+
+
+CREATE TABLE IF NOT EXISTS purse_merges
+  (purse_merge_request_serial_id BIGSERIAL -- UNIQUE
+  ,partner_serial_id INT8 REFERENCES partners(partner_serial_id) ON DELETE CASCADE
+  ,reserve_pub BYTEA NOT NULL CHECK(length(reserve_pub)=32)--REFERENCES reserves (reserve_pub) ON DELETE CASCADE
+  ,purse_pub BYTEA NOT NULL CHECK (LENGTH(purse_pub)=32) --REFERENCES purse_requests (purse_pub) ON DELETE CASCADE
+  ,merge_sig BYTEA NOT NULL CHECK (LENGTH(merge_sig)=64)
+  ,merge_timestamp INT8 NOT NULL
   ,PRIMARY KEY (purse_pub)
   ); -- partition by purse_pub; plus materialized index by reserve_pub!
-COMMENT ON TABLE mergers
-  IS 'Merge requests where a purse- and account-owner requested merging the purse into the account';
-COMMENT ON COLUMN mergers.partner_serial_id
+COMMENT ON TABLE purse_merges
+  IS 'Merge requests where a purse-owner requested merging the purse into the account';
+COMMENT ON COLUMN purse_merges.partner_serial_id
   IS 'identifies the partner exchange, NULL in case the target reserve lives at this exchange';
-COMMENT ON COLUMN mergers.reserve_pub
+COMMENT ON COLUMN purse_merges.reserve_pub
   IS 'public key of the target reserve';
-COMMENT ON COLUMN mergers.purse_pub
+COMMENT ON COLUMN purse_merges.purse_pub
   IS 'public key of the purse';
-COMMENT ON COLUMN mergers.reserve_sig
-  IS 'signature by the reserve private key affirming the merge, of type TALER_SIGNATURE_WALLET_ACCOUNT_MERGE';
-COMMENT ON COLUMN mergers.purse_sig
+COMMENT ON COLUMN purse_merges.merge_sig
   IS 'signature by the purse private key affirming the merge, of type TALER_SIGNATURE_WALLET_PURSE_MERGE';
-COMMENT ON COLUMN mergers.merge_timestamp
+COMMENT ON COLUMN purse_merges.merge_timestamp
   IS 'when was the merge message signed';
-COMMENT ON COLUMN mergers.purse_expiration
-  IS 'when is the purse set to expire';
-COMMENT ON COLUMN mergers.h_contract_terms
-  IS 'hash of the contract terms both sides are to agree upon';
-COMMENT ON COLUMN mergers.purse_val
-  IS 'amount to be transferred from the purse to the reserve (excludes deposit fees)';
-CREATE INDEX IF NOT EXISTS mergers_reserve_pub
-  ON mergers (reserve_pub);
-COMMENT ON INDEX mergers_reserve_pub
+CREATE INDEX IF NOT EXISTS purse_merges_reserve_pub
+  ON purse_merges (reserve_pub);
+COMMENT ON INDEX purse_merges_reserve_pub
   IS 'needed in reserve history computation';
 
+
+CREATE TABLE IF NOT EXISTS account_mergers
+  (account_merge_request_serial_id BIGSERIAL -- UNIQUE
+  ,reserve_pub BYTEA NOT NULL CHECK (LENGTH(reserve_pub)=32) -- REFERENCES reserves (reserve_pub) ON DELETE CASCADE
+  ,reserve_sig BYTEA NOT NULL CHECK (LENGTH(reserve_sig)=64)
+  ,purse_pub BYTEA NOT NULL CHECK (LENGTH(purse_pub)=32) -- REFERENCES purse_requests (purse_pub)
+  ,PRIMARY KEY (reserve_pub)
+  ); -- partition by purse_pub; plus materialized index by reserve_pub!
+COMMENT ON TABLE account_mergers
+  IS 'Merge requests where a purse- and account-owner requested merging the purse into the account';
+COMMENT ON COLUMN account_mergers.reserve_pub
+  IS 'public key of the target reserve';
+COMMENT ON COLUMN account_mergers.purse_pub
+  IS 'public key of the purse';
+COMMENT ON COLUMN account_mergers.reserve_sig
+  IS 'signature by the reserve private key affirming the merge, of type TALER_SIGNATURE_WALLET_ACCOUNT_MERGE';
+
+CREATE INDEX IF NOT EXISTS account_mergers_purse_pub
+  ON account_mergers (purse_pub);
+COMMENT ON INDEX account_mergers_purse_pub
+  IS 'needed when checking for a purse merge status';
+  
+
 CREATE TABLE IF NOT EXISTS contracts
   (contract_serial_id BIGSERIAL UNIQUE
   ,purse_pub BYTEA NOT NULL CHECK (LENGTH(purse_pub)=32)
@@ -1492,32 +1532,6 @@ COMMENT ON COLUMN close_requests.reserve_sig
 COMMENT ON COLUMN close_requests.close_val
   IS 'Balance of the reserve at the time of closing, to be wired to the associated bank account (minus the closing fee)';
 
-CREATE TABLE IF NOT EXISTS purse_requests
-  (purse_deposit_serial_id BIGSERIAL UNIQUE
-  ,purse_pub BYTEA NOT NULL CHECK (LENGTH(purse_pub)=32)
-  ,purse_expiration INT8 NOT NULL
-  ,h_contract_terms BYTEA NOT NULL CHECK (LENGTH(h_contract_terms)=64)
-  ,amount_with_fee_val INT8 NOT NULL
-  ,amount_with_fee_frac INT4 NOT NULL
-  ,balance_val INT8 NOT NULL
-  ,balance_frac INT4 NOT NULL
-  ,purse_sig BYTEA NOT NULL CHECK(LENGTH(purse_sig)=64)
-  ,PRIMARY KEY (purse_pub)
-  ); -- partition by purse_pub
-COMMENT ON TABLE purse_requests
-  IS 'Requests establishing purses, associating them with a contract but without a target reserve';
-COMMENT ON COLUMN purse_requests.purse_pub
-  IS 'Public key of the purse';
-COMMENT ON COLUMN purse_requests.purse_expiration
-  IS 'When the purse is set to expire';
-COMMENT ON COLUMN purse_requests.h_contract_terms
-  IS 'Hash of the contract the parties are to agree to';
-COMMENT ON COLUMN purse_requests.amount_with_fee_val
-  IS 'Total amount expected to be in the purse';
-COMMENT ON COLUMN purse_requests.balance_val
-  IS 'Total amount actually in the purse';
-COMMENT ON COLUMN purse_requests.purse_sig
-  IS 'Signature of the purse affirming the purse parameters, of type TALER_SIGNATURE_PURSE_REQUEST';
 
 CREATE TABLE IF NOT EXISTS purse_deposits
   (purse_deposit_serial_id BIGSERIAL UNIQUE
diff --git a/src/include/taler_crypto_lib.h b/src/include/taler_crypto_lib.h
index 809c6a8fe..ba7f05bcf 100644
--- a/src/include/taler_crypto_lib.h
+++ b/src/include/taler_crypto_lib.h
@@ -406,9 +406,9 @@ struct TALER_AgeCommitmentPublicKeyP
 
 
 /**
- * @brief Type of online public keys used by the wallet to establish a purse.
+ * @brief Type of online public keys used by the wallet to establish a purse and the associated contract meta data.
  */
-struct TALER_PursePublicKeyP
+struct TALER_PurseContractPublicKeyP
 {
   /**
    * Taler uses EdDSA for purse message signing.
@@ -418,10 +418,10 @@ struct TALER_PursePublicKeyP
 
 
 /**
- * @brief Type of online private keys used by the wallet for
- * a purse.
+ * @brief Type of online private keys used by the wallet to
+ * bind a purse to a particular contract (and other meta data).
  */
-struct TALER_PursePrivateKeyP
+struct TALER_PurseContractPrivateKeyP
 {
   /**
    * Taler uses EdDSA for online signatures sessions.
@@ -431,9 +431,47 @@ struct TALER_PursePrivateKeyP
 
 
 /**
- * @brief Type of signatures used by the wallet to sign purse messages online.
+ * @brief Type of signatures used by the wallet to sign purse creation messages online.
  */
-struct TALER_PurseSignatureP
+struct TALER_PurseContractSignatureP
+{
+  /**
+   * Taler uses EdDSA for online signatures sessions.
+   */
+  struct GNUNET_CRYPTO_EddsaSignature eddsa_signature;
+};
+
+
+/**
+ * @brief Type of online public keys used by the wallet to
+ * sign a merge of a purse into an account.
+ */
+struct TALER_PurseMergePublicKeyP
+{
+  /**
+   * Taler uses EdDSA for purse message signing.
+   */
+  struct GNUNET_CRYPTO_EddsaPublicKey eddsa_pub;
+};
+
+
+/**
+ * @brief Type of online private keys used by the wallet to
+ * sign a merge of a purse into an account.
+ */
+struct TALER_PurseMergePrivateKeyP
+{
+  /**
+   * Taler uses EdDSA for online signatures sessions.
+   */
+  struct GNUNET_CRYPTO_EddsaPrivateKey eddsa_priv;
+};
+
+
+/**
+ * @brief Type of signatures used by the wallet to sign purse merge requests online.
+ */
+struct TALER_PurseMergeSignatureP
 {
   /**
    * Taler uses EdDSA for online signatures sessions.
@@ -2621,6 +2659,7 @@ TALER_exchange_deposit_confirm_verify (
  *
  * @param purse_expiration when should the purse expire
  * @param h_contract_terms contract the two parties agree on
+ * @param merge_pub public key defining the merge capability
  * @param min_age age restriction to apply for deposits into the purse
  * @param amount total amount in the purse (including fees)
  * @param purse_priv key identifying the purse
@@ -2630,10 +2669,11 @@ void
 TALER_wallet_purse_create_sign (
   struct GNUNET_TIME_Timestamp purse_expiration,
   struct TALER_PrivateContractHashP *h_contract_terms,
+  const struct TALER_PurseMergePublicKeyP *merge_pub,
   uint32_t min_age,
   const struct TALER_Amount *amount,
-  const struct TALER_PursePrivateKeyP *purse_priv,
-  struct TALER_PurseSignatureP *purse_sig);
+  const struct TALER_PurseContractPrivateKeyP *purse_priv,
+  struct TALER_PurseContractSignatureP *purse_sig);
 
 
 /**
@@ -2641,6 +2681,7 @@ TALER_wallet_purse_create_sign (
  *
  * @param purse_expiration when should the purse expire
  * @param h_contract_terms contract the two parties agree on
+ * @param merge_pub public key defining the merge capability
  * @param min_age age restriction to apply for deposits into the purse
  * @param amount total amount in the purse (including fees)
  * @param purse_pub purse’s public key
@@ -2651,10 +2692,11 @@ enum GNUNET_GenericReturnValue
 TALER_wallet_purse_create_verify (
   struct GNUNET_TIME_Timestamp purse_expiration,
   struct TALER_PrivateContractHashP *h_contract_terms,
+  const struct TALER_PurseMergePublicKeyP *merge_pub,
   uint32_t min_age,
   const struct TALER_Amount *amount,
-  const struct TALER_PursePublicKeyP *purse_pub,
-  const struct TALER_PurseSignatureP *purse_sig);
+  const struct TALER_PurseContractPublicKeyP *purse_pub,
+  const struct TALER_PurseContractSignatureP *purse_sig);
 
 
 /**
@@ -2665,8 +2707,8 @@ TALER_wallet_purse_create_verify (
  */
 void
 TALER_wallet_purse_status_sign (
-  const struct TALER_PursePrivateKeyP *purse_priv,
-  struct TALER_PurseSignatureP *purse_sig);
+  const struct TALER_PurseContractPrivateKeyP *purse_priv,
+  struct TALER_PurseContractSignatureP *purse_sig);
 
 
 /**
@@ -2678,8 +2720,8 @@ TALER_wallet_purse_status_sign (
  */
 enum GNUNET_GenericReturnValue
 TALER_wallet_purse_status_verify (
-  const struct TALER_PursePublicKeyP *purse_pub,
-  const struct TALER_PurseSignatureP *purse_sig);
+  const struct TALER_PurseContractPublicKeyP *purse_pub,
+  const struct TALER_PurseContractSignatureP *purse_sig);
 
 
 /**
@@ -2692,7 +2734,7 @@ TALER_wallet_purse_status_verify (
  */
 void
 TALER_wallet_purse_deposit_sign (
-  const struct TALER_PursePublicKeyP *purse_pub,
+  const struct TALER_PurseContractPublicKeyP *purse_pub,
   const struct TALER_Amount *amount,
   const struct TALER_CoinSpendPrivateKeyP *coin_priv,
   struct TALER_CoinSpendSignatureP *coin_sig);
@@ -2709,7 +2751,7 @@ TALER_wallet_purse_deposit_sign (
  */
 enum GNUNET_GenericReturnValue
 TALER_wallet_purse_deposit_verify (
-  const struct TALER_PursePublicKeyP *purse_pub,
+  const struct TALER_PurseContractPublicKeyP *purse_pub,
   const struct TALER_Amount *amount,
   const struct TALER_CoinSpendPublicKeyP *coin_pub,
   const struct TALER_CoinSpendSignatureP *coin_sig);
@@ -2721,15 +2763,17 @@ TALER_wallet_purse_deposit_verify (
  * @param reserve_url identifies the location of the reserve,
  *        included public key must match @e reserve_priv
  * @param merge_timestamp time when the merge happened
- * @param purse_priv key identifying the purse
- * @param[out] purse_sig resulting signature
+ * @param purse_pub key identifying the purse
+ * @param merge_priv key identifying the merge capability
+ * @param[out] merge_sig resulting signature
  */
 void
 TALER_wallet_purse_merge_sign (
   const char *reserve_url,
   struct GNUNET_TIME_Timestamp merge_timestamp,
-  const struct TALER_PursePrivateKeyP *purse_priv,
-  struct TALER_PurseSignatureP *purse_sig);
+  const struct TALER_PurseContractPublicKeyP *purse_pub,
+  const struct TALER_PurseMergePrivateKeyP *merge_priv,
+  struct TALER_PurseMergeSignatureP *merge_sig);
 
 
 /**
@@ -2739,22 +2783,22 @@ TALER_wallet_purse_merge_sign (
  *        included public key must match @e reserve_priv
  * @param merge_timestamp time when the merge happened
  * @param purse_pub public key of the purse to merge
- * @param purse_sig the signature made with purpose #TALER_SIGNATURE_WALLET_PURSE_MERGE
+ * @param merge_pub public key of the merge capability
+ * @param merge_sig the signature made with purpose #TALER_SIGNATURE_WALLET_PURSE_MERGE
  * @return #GNUNET_OK if the signature is valid
  */
 enum GNUNET_GenericReturnValue
 TALER_wallet_purse_merge_verify (
   const char *reserve_url,
   struct GNUNET_TIME_Timestamp merge_timestamp,
-  const struct TALER_PursePublicKeyP *purse_pub,
-  const struct TALER_PurseSignatureP *purse_sig);
+  const struct TALER_PurseContractPublicKeyP *purse_pub,
+  const struct TALER_PurseMergePublicKeyP *merge_pub,
+  const struct TALER_PurseMergeSignatureP *merge_sig);
 
 
 /**
  * Sign a request by an account to merge a purse.
  *
- * @param reserve_url identifies the location of the reserve,
- *        included public key must match @e reserve_priv
  * @param merge_timestamp time when the merge happened
  * @param purse_pub public key of the purse to merge
  * @param purse_expiration when should the purse expire
@@ -2766,9 +2810,8 @@ TALER_wallet_purse_merge_verify (
  */
 void
 TALER_wallet_account_merge_sign (
-  const char *reserve_url,
   struct GNUNET_TIME_Timestamp merge_timestamp,
-  const struct TALER_PursePublicKeyP *purse_pub,
+  const struct TALER_PurseContractPublicKeyP *purse_pub,
   struct GNUNET_TIME_Timestamp purse_expiration,
   struct TALER_PrivateContractHashP *h_contract_terms,
   const struct TALER_Amount *amount,
@@ -2780,8 +2823,6 @@ TALER_wallet_account_merge_sign (
 /**
  * Verify an account's request to merge a purse.
  *
- * @param reserve_url identifies the location of the reserve,
- *        included public key must match @e reserve_priv
  * @param merge_timestamp time when the merge happened
  * @param purse_pub public key of the purse to merge
  * @param purse_expiration when should the purse expire
@@ -2794,9 +2835,8 @@ TALER_wallet_account_merge_sign (
  */
 enum GNUNET_GenericReturnValue
 TALER_wallet_account_merge_verify (
-  const char *reserve_url,
   struct GNUNET_TIME_Timestamp merge_timestamp,
-  const struct TALER_PursePublicKeyP *purse_pub,
+  const struct TALER_PurseContractPublicKeyP *purse_pub,
   struct GNUNET_TIME_Timestamp purse_expiration,
   struct TALER_PrivateContractHashP *h_contract_terms,
   const struct TALER_Amount *amount,
diff --git a/src/include/taler_exchangedb_plugin.h b/src/include/taler_exchangedb_plugin.h
index 5b8aa53bd..074e952ea 100644
--- a/src/include/taler_exchangedb_plugin.h
+++ b/src/include/taler_exchangedb_plugin.h
@@ -4323,6 +4323,7 @@ struct TALER_EXCHANGEDB_Plugin
   enum GNUNET_DB_QueryStatus
   (*delete_shard_locks)(void *cls);
 
+
   /**
    * Function called to save the configuration of an extension
    * (age-restriction, peer2peer, ...)
@@ -4337,6 +4338,7 @@ struct TALER_EXCHANGEDB_Plugin
                           const char *extension_name,
                           const char *config);
 
+
   /**
    * Function called to retrieve the configuration of an extension
    * (age-restriction, peer2peer, ...)
@@ -4351,6 +4353,120 @@ struct TALER_EXCHANGEDB_Plugin
                           const char *extension_name,
                           char **config);
 
+
+  enum GNUNET_DB_QueryStatus
+  (*insert_partner)(void *cls,
+                    const struct TALER_MasterPublicKeyP *master_pub,
+                    struct GNUNET_TIME_Timestamp start_date,
+                    struct GNUNET_TIME_Timestamp end_date,
+                    struct GNUNET_TIME_Relative wad_frequency,
+                    const struct TALER_Amount *wad_fee,
+                    const char *partner_base_url,
+                    const struct TALER_MasterSignatureP *master_sig);
+
+
+  enum GNUNET_DB_QueryStatus
+  (*insert_contract)(void *cls,
+                     const struct TALER_PurseContractPublicKeyP *purse_pub,
+                     const struct TALER_ContractDiffiePublicP *pub_ckey,
+                     size_t econtract_size,
+                     const void *econtract);
+
+
+  enum GNUNET_DB_QueryStatus
+  (*select_contract)(void *cls,
+                     const struct TALER_PurseContractPublicKeyP *purse_pub,
+                     struct TALER_ContractDiffiePublicP *pub_ckey,
+                     size_t *econtract_size,
+                     void **econtract);
+
+
+  enum GNUNET_DB_QueryStatus
+  (*insert_purse_request)(
+    void *cls,
+    const struct TALER_PurseContractPublicKeyP *purse_pub,
+    const struct TALER_PurseMergePublicKeyP *merge_pub,
+    struct GNUNET_TIME_Timestamp purse_expiration,
+    const struct TALER_PrivateContractHashP *h_contract_terms,
+    const struct TALER_Amount *amount,
+    const struct TALER_PurseContractSignatureP *purse_sig);
+
+
+  enum GNUNET_DB_QueryStatus
+  (*select_purse_request)(
+    void *cls,
+    const struct TALER_PurseContractPublicKeyP *purse_pub,
+    struct TALER_PurseMergePublicKeyP *merge_pub,
+    struct GNUNET_TIME_Timestamp *purse_expiration,
+    struct TALER_PrivateContractHashP *h_contract_terms,
+    struct TALER_Amount *target_amount,
+    struct TALER_Amount *balance,
+    struct TALER_PurseContractSignatureP *purse_sig);
+
+
+  enum GNUNET_DB_QueryStatus
+  (*insert_purse_deposit)(
+    void *cls,
+    const struct TALER_PurseContractPublicKeyP *purse_pub,
+    const struct TALER_CoinSpendPublicKeyP *coin_pub,
+    const struct TALER_Amount *amount,
+    const struct TALER_CoinSpendSignatureP *coin_sig);
+
+
+  enum GNUNET_DB_QueryStatus
+  (*insert_purse_merge)(
+    void *cls,
+    const struct TALER_PurseContractPublicKeyP *purse_pub,
+    const struct TALER_PurseMergePublicKeyP *merge_pub,
+    const struct TALER_PurseMergeSignatureP *merge_sig,
+    const struct GNUNET_TIME_Timestamp merge_timestamp,
+    uint64_t partner_serial_id,
+    const struct TALER_ReservePublicKeyP *reserve_pub);
+
+
+  enum GNUNET_DB_QueryStatus
+  (*select_purse_merge)(
+    void *cls,
+    const struct TALER_PurseContractPublicKeyP *purse_pub,
+    struct TALER_PurseMergePublicKeyP *merge_pub,
+    struct TALER_PurseMergeSignatureP *merge_sig,
+    struct GNUNET_TIME_Timestamp *merge_timestamp,
+    uint64_t *partner_serial_id,
+    struct TALER_ReservePublicKeyP *reserve_pub);
+
+
+  enum GNUNET_DB_QueryStatus
+  (*insert_account_merge)(
+    void *cls,
+    const struct TALER_PurseContractPublicKeyP *purse_pub,
+    const struct TALER_ReservePublicKeyP *reserve_pub,
+    const struct TALER_ReserveSignatureP *reserve_sig);
+
+
+  enum GNUNET_DB_QueryStatus
+  (*select_account_merge)(
+    void *cls,
+    const struct TALER_PurseContractPublicKeyP *purse_pub,
+    struct TALER_ReservePublicKeyP *reserve_pub,
+    struct TALER_ReserveSignatureP *reserve_sig);
+
+
+  enum GNUNET_DB_QueryStatus
+  (*insert_history_request)(
+    void *cls,
+    const struct TALER_ReservePublicKeyP *reserve_pub,
+    const struct TALER_ReserveSignatureP *reserve_sig,
+    struct GNUNET_TIME_Absolute request_timestamp,
+    const struct TALER_Amount *history);
+
+
+  enum GNUNET_DB_QueryStatus
+  (*insert_close_request)(void *cls,
+                          const struct TALER_ReservePublicKeyP *reserve_pub,
+                          const struct TALER_ReserveSignatureP *reserve_sig,
+                          struct TALER_Amount *final_balance);
+
+
 };
 
 #endif /* _TALER_EXCHANGE_DB_H */
diff --git a/src/util/wallet_signatures.c b/src/util/wallet_signatures.c
index c2303e064..097b8ed8a 100644
--- a/src/util/wallet_signatures.c
+++ b/src/util/wallet_signatures.c
@@ -779,6 +779,11 @@ struct TALER_PurseCreatePS
   struct TALER_PrivateContractHashP h_contract_terms;
 
   /**
+   * Public key identifying the merge capability.
+   */
+  struct TALER_PurseMergePublicKeyP merge_pub;
+
+  /**
    * Minimum age required for payments into this purse.
    */
   uint32_t min_age GNUNET_PACKED;
@@ -790,16 +795,18 @@ void
 TALER_wallet_purse_create_sign (
   struct GNUNET_TIME_Timestamp purse_expiration,
   struct TALER_PrivateContractHashP *h_contract_terms,
+  const struct TALER_PurseMergePublicKeyP *merge_pub,
   uint32_t min_age,
   const struct TALER_Amount *amount,
-  const struct TALER_PursePrivateKeyP *purse_priv,
-  struct TALER_PurseSignatureP *purse_sig)
+  const struct TALER_PurseContractPrivateKeyP *purse_priv,
+  struct TALER_PurseContractSignatureP *purse_sig)
 {
   struct TALER_PurseCreatePS pm = {
     .purpose.size = htonl (sizeof (pm)),
     .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_PURSE_CREATE),
     .purse_expiration = GNUNET_TIME_timestamp_hton (purse_expiration),
     .h_contract_terms = *h_contract_terms,
+    .merge_pub = *merge_pub,
     .min_age = htonl (min_age)
   };
 
@@ -815,16 +822,18 @@ enum GNUNET_GenericReturnValue
 TALER_wallet_purse_create_verify (
   struct GNUNET_TIME_Timestamp purse_expiration,
   struct TALER_PrivateContractHashP *h_contract_terms,
+  const struct TALER_PurseMergePublicKeyP *merge_pub,
   uint32_t min_age,
   const struct TALER_Amount *amount,
-  const struct TALER_PursePublicKeyP *purse_pub,
-  const struct TALER_PurseSignatureP *purse_sig)
+  const struct TALER_PurseContractPublicKeyP *purse_pub,
+  const struct TALER_PurseContractSignatureP *purse_sig)
 {
   struct TALER_PurseCreatePS pm = {
     .purpose.size = htonl (sizeof (pm)),
     .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_PURSE_CREATE),
     .purse_expiration = GNUNET_TIME_timestamp_hton (purse_expiration),
     .h_contract_terms = *h_contract_terms,
+    .merge_pub = *merge_pub,
     .min_age = htonl (min_age)
   };
 
@@ -840,8 +849,8 @@ TALER_wallet_purse_create_verify (
 
 void
 TALER_wallet_purse_status_sign (
-  const struct TALER_PursePrivateKeyP *purse_priv,
-  struct TALER_PurseSignatureP *purse_sig)
+  const struct TALER_PurseContractPrivateKeyP *purse_priv,
+  struct TALER_PurseContractSignatureP *purse_sig)
 {
   struct GNUNET_CRYPTO_EccSignaturePurpose purpose = {
     .size = htonl (sizeof (purpose)),
@@ -857,8 +866,8 @@ TALER_wallet_purse_status_sign (
 
 enum GNUNET_GenericReturnValue
 TALER_wallet_purse_status_verify (
-  const struct TALER_PursePublicKeyP *purse_pub,
-  const struct TALER_PurseSignatureP *purse_sig)
+  const struct TALER_PurseContractPublicKeyP *purse_pub,
+  const struct TALER_PurseContractSignatureP *purse_sig)
 {
   struct GNUNET_CRYPTO_EccSignaturePurpose purpose = {
     .size = htonl (sizeof (purpose)),
@@ -891,14 +900,14 @@ struct TALER_PurseDepositPS
   /**
    * Purse to deposit funds into.
    */
-  struct TALER_PursePublicKeyP purse_pub;
+  struct TALER_PurseContractPublicKeyP purse_pub;
 
 };
 
 
 void
 TALER_wallet_purse_deposit_sign (
-  const struct TALER_PursePublicKeyP *purse_pub,
+  const struct TALER_PurseContractPublicKeyP *purse_pub,
   const struct TALER_Amount *amount,
   const struct TALER_CoinSpendPrivateKeyP *coin_priv,
   struct TALER_CoinSpendSignatureP *coin_sig)
@@ -919,7 +928,7 @@ TALER_wallet_purse_deposit_sign (
 
 enum GNUNET_GenericReturnValue
 TALER_wallet_purse_deposit_verify (
-  const struct TALER_PursePublicKeyP *purse_pub,
+  const struct TALER_PurseContractPublicKeyP *purse_pub,
   const struct TALER_Amount *amount,
   const struct TALER_CoinSpendPublicKeyP *coin_pub,
   const struct TALER_CoinSpendSignatureP *coin_sig)
@@ -957,6 +966,11 @@ struct TALER_PurseMergePS
   struct GNUNET_TIME_TimestampNBO merge_timestamp;
 
   /**
+   * Which purse is being merged?
+   */
+  struct TALER_PurseContractPublicKeyP purse_pub;
+
+  /**
    * Which reserve should the purse be merged with.
    * Hash of the reserve's payto:// URI.
    */
@@ -969,20 +983,22 @@ void
 TALER_wallet_purse_merge_sign (
   const char *reserve_url,
   struct GNUNET_TIME_Timestamp merge_timestamp,
-  const struct TALER_PursePrivateKeyP *purse_priv,
-  struct TALER_PurseSignatureP *purse_sig)
+  const struct TALER_PurseContractPublicKeyP *purse_pub,
+  const struct TALER_PurseMergePrivateKeyP *merge_priv,
+  struct TALER_PurseMergeSignatureP *merge_sig)
 {
   struct TALER_PurseMergePS pm = {
     .purpose.size = htonl (sizeof (pm)),
     .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_PURSE_MERGE),
     .merge_timestamp = GNUNET_TIME_timestamp_hton (merge_timestamp),
+    .purse_pub = *purse_pub
   };
 
   TALER_payto_hash (reserve_url,
                     &pm.h_payto);
-  GNUNET_CRYPTO_eddsa_sign (&purse_priv->eddsa_priv,
+  GNUNET_CRYPTO_eddsa_sign (&merge_priv->eddsa_priv,
                             &pm,
-                            &purse_sig->eddsa_signature);
+                            &merge_sig->eddsa_signature);
 }
 
 
@@ -990,13 +1006,15 @@ enum GNUNET_GenericReturnValue
 TALER_wallet_purse_merge_verify (
   const char *reserve_url,
   struct GNUNET_TIME_Timestamp merge_timestamp,
-  const struct TALER_PursePublicKeyP *purse_pub,
-  const struct TALER_PurseSignatureP *purse_sig)
+  const struct TALER_PurseContractPublicKeyP *purse_pub,
+  const struct TALER_PurseMergePublicKeyP *merge_pub,
+  const struct TALER_PurseMergeSignatureP *merge_sig)
 {
   struct TALER_PurseMergePS pm = {
     .purpose.size = htonl (sizeof (pm)),
     .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_PURSE_MERGE),
     .merge_timestamp = GNUNET_TIME_timestamp_hton (merge_timestamp),
+    .purse_pub = *purse_pub
   };
 
   TALER_payto_hash (reserve_url,
@@ -1004,8 +1022,8 @@ TALER_wallet_purse_merge_verify (
   return GNUNET_CRYPTO_eddsa_verify (
     TALER_SIGNATURE_WALLET_ACCOUNT_MERGE,
     &pm,
-    &purse_sig->eddsa_signature,
-    &purse_pub->eddsa_pub);
+    &merge_sig->eddsa_signature,
+    &merge_pub->eddsa_pub);
 }
 
 
@@ -1031,12 +1049,6 @@ struct TALER_AccountMergePS
   struct TALER_AmountNBO purse_amount;
 
   /**
-   * Which reserve should the purse be merged with.
-   * Hash of the reserve's payto:// URI.
-   */
-  struct TALER_PaytoHashP h_payto;
-
-  /**
    * Contract this purse pays for.
    */
   struct TALER_PrivateContractHashP h_contract_terms;
@@ -1044,7 +1056,7 @@ struct TALER_AccountMergePS
   /**
    * Purse to merge.
    */
-  struct TALER_PursePublicKeyP purse_pub;
+  struct TALER_PurseContractPublicKeyP purse_pub;
 
   /**
    * Time when the purse is merged into the reserve.
@@ -1060,9 +1072,8 @@ struct TALER_AccountMergePS
 
 void
 TALER_wallet_account_merge_sign (
-  const char *reserve_url,
   struct GNUNET_TIME_Timestamp merge_timestamp,
-  const struct TALER_PursePublicKeyP *purse_pub,
+  const struct TALER_PurseContractPublicKeyP *purse_pub,
   struct GNUNET_TIME_Timestamp purse_expiration,
   struct TALER_PrivateContractHashP *h_contract_terms,
   const struct TALER_Amount *amount,
@@ -1082,8 +1093,6 @@ TALER_wallet_account_merge_sign (
 
   TALER_amount_hton (&pm.purse_amount,
                      amount);
-  TALER_payto_hash (reserve_url,
-                    &pm.h_payto);
   GNUNET_CRYPTO_eddsa_sign (&reserve_priv->eddsa_priv,
                             &pm,
                             &reserve_sig->eddsa_signature);
@@ -1092,9 +1101,8 @@ TALER_wallet_account_merge_sign (
 
 enum GNUNET_GenericReturnValue
 TALER_wallet_account_merge_verify (
-  const char *reserve_url,
   struct GNUNET_TIME_Timestamp merge_timestamp,
-  const struct TALER_PursePublicKeyP *purse_pub,
+  const struct TALER_PurseContractPublicKeyP *purse_pub,
   struct GNUNET_TIME_Timestamp purse_expiration,
   struct TALER_PrivateContractHashP *h_contract_terms,
   const struct TALER_Amount *amount,
@@ -1114,8 +1122,6 @@ TALER_wallet_account_merge_verify (
 
   TALER_amount_hton (&pm.purse_amount,
                      amount);
-  TALER_payto_hash (reserve_url,
-                    &pm.h_payto);
   return GNUNET_CRYPTO_eddsa_verify (
     TALER_SIGNATURE_WALLET_ACCOUNT_MERGE,
     &pm,