diff options
Diffstat (limited to 'src/lib')
| -rw-r--r-- | src/lib/exchange_api_melt.c | 83 |
1 files changed, 77 insertions, 6 deletions
diff --git a/src/lib/exchange_api_melt.c b/src/lib/exchange_api_melt.c index 2c1e85d7b..989c6501a 100644 --- a/src/lib/exchange_api_melt.c +++ b/src/lib/exchange_api_melt.c @@ -76,6 +76,11 @@ struct TALER_EXCHANGE_MeltHandle struct MeltData *md; /** + * Public key of the coin being melted. + */ + struct TALER_CoinSpendPublicKeyP coin_pub; + + /** * @brief Public information about the coin's denomination key */ struct TALER_EXCHANGE_DenomPublicKey dki; @@ -155,6 +160,48 @@ verify_melt_signature_ok (struct TALER_EXCHANGE_MeltHandle *mh, /** * Verify that the signatures on the "409 CONFLICT" response from the + * exchange demonstrating customer denomination key differences + * resulting from coin private key reuse are valid. + * + * @param mh melt handle + * @param json json reply with the signature(s) and transaction history + * @return #GNUNET_OK if the signature(s) is valid, #GNUNET_SYSERR if not + */ +static int +verify_melt_signature_denom_conflict (struct TALER_EXCHANGE_MeltHandle *mh, + const json_t *json) + +{ + json_t *history; + struct TALER_Amount total; + struct GNUNET_HashCode h_denom_pub; + + memset (&h_denom_pub, + 0, + sizeof (h_denom_pub)); + history = json_object_get (json, + "history"); + if (GNUNET_OK != + TALER_EXCHANGE_verify_coin_history (&mh->dki, + mh->dki.value.currency, + &mh->coin_pub, + history, + &h_denom_pub, + &total)) + { + GNUNET_break_op (0); + return GNUNET_SYSERR; + } + if (0 != GNUNET_memcmp (&mh->dki.h_key, + &h_denom_pub)) + return GNUNET_OK; /* indeed, proof with different denomination key provided */ + /* invalid proof provided */ + return GNUNET_SYSERR; +} + + +/** + * Verify that the signatures on the "409 CONFLICT" response from the * exchange demonstrating customer double-spending are valid. * * @param mh melt handle @@ -162,8 +209,8 @@ verify_melt_signature_ok (struct TALER_EXCHANGE_MeltHandle *mh, * @return #GNUNET_OK if the signature(s) is valid, #GNUNET_SYSERR if not */ static int -verify_melt_signature_conflict (struct TALER_EXCHANGE_MeltHandle *mh, - const json_t *json) +verify_melt_signature_spend_conflict (struct TALER_EXCHANGE_MeltHandle *mh, + const json_t *json) { json_t *history; struct TALER_Amount original_value; @@ -329,15 +376,38 @@ handle_melt_finished (void *cls, hr.hint = TALER_JSON_get_error_hint (j); break; case MHD_HTTP_CONFLICT: - /* Double spending; check signatures on transaction history */ - if (GNUNET_OK != - verify_melt_signature_conflict (mh, - j)) + hr.ec = TALER_JSON_get_error_code (j); + switch (hr.ec) { + case TALER_EC_MELT_INSUFFICIENT_FUNDS: + /* Double spending; check signatures on transaction history */ + if (GNUNET_OK != + verify_melt_signature_spend_conflict (mh, + j)) + { + GNUNET_break_op (0); + hr.http_status = 0; + hr.ec = TALER_EC_MELT_INVALID_SIGNATURE_BY_EXCHANGE; + hr.hint = TALER_JSON_get_error_hint (j); + } + break; + case TALER_EC_COIN_CONFLICTING_DENOMINATION_KEY: + if (GNUNET_OK != + verify_melt_signature_denom_conflict (mh, + j)) + { + GNUNET_break_op (0); + hr.http_status = 0; + hr.ec = TALER_EC_MELT_INVALID_SIGNATURE_BY_EXCHANGE; + hr.hint = TALER_JSON_get_error_hint (j); + } + break; + default: GNUNET_break_op (0); hr.http_status = 0; hr.ec = TALER_EC_MELT_INVALID_SIGNATURE_BY_EXCHANGE; hr.hint = TALER_JSON_get_error_hint (j); + break; } break; case MHD_HTTP_FORBIDDEN: @@ -485,6 +555,7 @@ TALER_EXCHANGE_melt (struct TALER_EXCHANGE_Handle *exchange, /* and now we can at last begin the actual request handling */ mh = GNUNET_new (struct TALER_EXCHANGE_MeltHandle); mh->exchange = exchange; + mh->coin_pub = melt.coin_pub; mh->dki = *dki; mh->dki.key.rsa_public_key = NULL; /* lifetime not warranted, so better not copy the pointer */ |