diff options
Diffstat (limited to 'src/include/taler_signatures.h')
| -rw-r--r-- | src/include/taler_signatures.h | 239 |
1 files changed, 161 insertions, 78 deletions
diff --git a/src/include/taler_signatures.h b/src/include/taler_signatures.h index b1b578236..007a309f3 100644 --- a/src/include/taler_signatures.h +++ b/src/include/taler_signatures.h @@ -1,6 +1,6 @@ /* This file is part of TALER - Copyright (C) 2014 Christian Grothoff (and other contributing authors) + Copyright (C) 2014, 2015 Christian Grothoff (and other contributing authors) TALER is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software @@ -28,10 +28,20 @@ #ifndef TALER_SIGNATURES_H #define TALER_SIGNATURES_H -#include <gnunet/gnunet_util_lib.h> #include "taler_util.h" /** + * Cut-and-choose size for refreshing. Client looses the gamble (of + * unaccountable transfers) with probability 1/KAPPA. Refresh cost + * increases linearly with KAPPA, and 3 is sufficient up to a + * income/sales tax of 66% of total transaction value. As there is + * no good reason to change this security parameter, we declare it + * fixed and part of the protocol. + */ +#define KAPPA 3 + + +/** * Purpose for signing public keys signed * by the mint master key. */ @@ -62,28 +72,21 @@ #define TALER_SIGNATURE_REFRESH_MELT_COIN 5 /** - * Signature where the refresh session confirms - * the commits. - */ -#define TALER_SIGNATURE_REFRESH_MELT_SESSION 6 - -/** * Signature where the mint (current signing key) * confirms the no-reveal index for cut-and-choose and * the validity of the melted coins. */ -#define TALER_SIGNATURE_REFRESH_MELT_RESPONSE 7 +#define TALER_SIGNATURE_REFRESH_MELT_RESPONSE 6 /** - * Signature where coins confirm that they want - * to be melted into a certain session. + * Signature where the Mint confirms a deposit request. */ -#define TALER_SIGNATURE_REFRESH_MELT_CONFIRM 9 +#define TALER_SIGNATURE_MINT_DEPOSIT 7 /** - * Signature where the Mint confirms a deposit request. + * Signature where the Mint confirms the full /keys response set. */ -#define TALER_SIGNATURE_MINT_DEPOSIT 10 +#define TALER_SIGNATURE_KEYS_SET 8 /***********************/ @@ -129,7 +132,16 @@ struct TALER_WithdrawRequest * Reserve public key (which reserve to withdraw from). This is * the public key which must match the signature. */ - struct GNUNET_CRYPTO_EddsaPublicKey reserve_pub; + struct TALER_ReservePublicKey reserve_pub; + + /** + * Value of the coin being minted (matching the denomination key) + * plus the transaction fee. We include this in what is being + * signed so that we can verify a reserve's remaining total balance + * without needing to access the respective denomination key + * information each time. + */ + struct TALER_AmountNBO amount_with_fee; /** * Hash of the denomination public key for the coin that is withdrawn. @@ -171,14 +183,16 @@ struct TALER_DepositRequest uint64_t transaction_id GNUNET_PACKED; /** - * Amount to be deposited. + * Amount to be deposited, including fee. */ - struct TALER_AmountNBO amount; + struct TALER_AmountNBO amount_with_fee; + /* FIXME: we should probably also include the value of + the depositing fee here as well! */ /** * The coin's public key. */ - struct GNUNET_CRYPTO_EcdsaPublicKey coin_pub; + struct TALER_CoinSpendPublicKey coin_pub; }; @@ -211,19 +225,22 @@ struct TALER_DepositConfirmation uint64_t transaction_id GNUNET_PACKED; /** - * Amount to be deposited. + * Amount to be deposited, including fee. */ - struct TALER_AmountNBO amount; + struct TALER_AmountNBO amount_with_fee; + + /* FIXME: we should probably also include the value of + the depositing fee here as well! */ /** * The coin's public key. */ - struct GNUNET_CRYPTO_EcdsaPublicKey coin_pub; + struct TALER_CoinSpendPublicKey coin_pub; /** * The Merchant's public key. */ - struct GNUNET_CRYPTO_EddsaPublicKey merchant; + struct TALER_MerchantPublicKey merchant; }; @@ -240,51 +257,27 @@ struct RefreshMeltCoinSignature struct GNUNET_CRYPTO_EccSignaturePurpose purpose; /** - * Which melting operation should the coin become a part of. - */ - struct GNUNET_HashCode melt_hash; - - /** - * How much of the value of the coin should be melted? - * This amount includes the fees, so the final amount contributed - * to the melt is this value minus the fee for melting the coin. - */ - struct TALER_AmountNBO amount; - - /** - * The coin's public key. - */ - struct GNUNET_CRYPTO_EcdsaPublicKey coin_pub; -}; - - -/** - * Message signed by a coin to indicate that the coin should - * be melted. - */ -struct RefreshMeltSessionSignature -{ - /** - * Purpose is #TALER_SIGNATURE_REFRESH_MELT_SESSION + * Which melting session should the coin become a part of. */ - struct GNUNET_CRYPTO_EccSignaturePurpose purpose; + struct GNUNET_HashCode session_hash; /** - * Which melting operation should the coin become a part of. + * How much of the value of the coin should be melted? This amount + * includes the fees, so the final amount contributed to the melt is + * this value minus the fee for melting the coin. We include the + * fee in what is being signed so that we can verify a reserve's + * remaining total balance without needing to access the respective + * denomination key information each time. */ - struct GNUNET_HashCode melt_hash; + struct TALER_AmountNBO amount_with_fee; - /** - * Public key of the refresh session for which - * @e melt_client_signature must be a valid signature. - */ - struct GNUNET_CRYPTO_EddsaPublicKey session_key; + /* FIXME: we should probably also include the value of + the melting fee here as well! */ /** - * What is the total value of the coins created during the - * refresh, excluding fees? + * The coin's public key. */ - struct TALER_AmountNBO amount; + struct TALER_CoinSpendPublicKey coin_pub; }; @@ -314,57 +307,147 @@ struct RefreshMeltResponseSignatureBody /** - * Message signed by the client requesting the final - * result of the melting operation. + * Information about a signing key of the mint. Signing keys are used + * to sign mint messages other than coins, i.e. to confirm that a + * deposit was successful or that a refresh was accepted. */ -struct RefreshMeltConfirmSignRequestBody +struct TALER_MINT_SignKeyIssue { /** - * Purpose is #TALER_SIGNATURE_REFRESH_MELT_CONFIRM. + * Signature over the signing key (by the master key of the mint). + */ + struct TALER_MasterSignature signature; + + /** + * Purpose is #TALER_SIGNATURE_MASTER_SIGNKEY. */ struct GNUNET_CRYPTO_EccSignaturePurpose purpose; /** - * FIXME. + * Master public key of the mint corresponding to @e signature. + * This is the long-term offline master key of the mint. + */ + struct TALER_MasterPublicKey master_pub; + + /** + * When does this signing key begin to be valid? */ - struct GNUNET_CRYPTO_EddsaPublicKey session_pub; + struct GNUNET_TIME_AbsoluteNBO start; + + /** + * When does this signing key expire? Note: This is + * currently when the Mint will definitively stop using it. + * This does not mean that all signatures with tkey key are + * afterwards invalid. + */ + struct GNUNET_TIME_AbsoluteNBO expire; + + /** + * The public online signing key that the mint will use + * between @e start and @e expire. + */ + struct TALER_MintPublicKey signkey_pub; }; /** - * FIXME + * Signature made by the mint over the full set of keys, used + * to detect cheating mints that give out different sets to + * different users. */ -struct TALER_MINT_SignKeyIssue +struct TALER_MINT_KeySetSignature { - struct GNUNET_CRYPTO_EddsaSignature signature; + + /** + * Purpose is #TALER_SIGNATURE_KEYS_SET + */ struct GNUNET_CRYPTO_EccSignaturePurpose purpose; - struct GNUNET_CRYPTO_EddsaPublicKey master_pub; - struct GNUNET_TIME_AbsoluteNBO start; - struct GNUNET_TIME_AbsoluteNBO expire; - struct GNUNET_CRYPTO_EddsaPublicKey signkey_pub; + + /** + * Time of the key set issue. + */ + struct GNUNET_TIME_AbsoluteNBO list_issue_date; + + /** + * Hash over the "inner" JSON with the key set. + */ + struct GNUNET_HashCode hc; }; /** - * FIXME + * Information about a denomination key. Denomination keys + * are used to sign coins of a certain value into existence. */ struct TALER_MINT_DenomKeyIssue { - struct GNUNET_CRYPTO_EddsaSignature signature; + /** + * Signature over this struct to affirm the validity + * of the key. + */ + struct TALER_MasterSignature signature; + + /** + * Purpose is #TALER_SIGNATURE_MASTER_DENOM. + */ struct GNUNET_CRYPTO_EccSignaturePurpose purpose; - struct GNUNET_CRYPTO_EddsaPublicKey master; + + /** + * The long-term offline master key of the mint that was + * used to create @e signature. + */ + struct TALER_MasterPublicKey master; + + /** + * 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. + */ 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. + */ struct GNUNET_TIME_AbsoluteNBO expire_spend; - // FIXME: does not work like this: - struct GNUNET_CRYPTO_rsa_PublicKey * denom_pub; + + /** + * 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. + */ + struct GNUNET_HashCode denom_hash; +}; GNUNET_NETWORK_STRUCT_END |