diff options
Diffstat (limited to 'src/include/taler_crypto_lib.h')
| -rw-r--r-- | src/include/taler_crypto_lib.h | 213 |
1 files changed, 177 insertions, 36 deletions
diff --git a/src/include/taler_crypto_lib.h b/src/include/taler_crypto_lib.h index ab5202baa..9bbf29de4 100644 --- a/src/include/taler_crypto_lib.h +++ b/src/include/taler_crypto_lib.h @@ -306,37 +306,6 @@ struct TALER_MasterSignatureP struct GNUNET_CRYPTO_EddsaSignature eddsa_signature; }; -/* - * @brief Type of a list of age groups, represented as bit mask. - * - * The bits set in the mask mark the edges at the beginning of a next age - * group. F.e. for the age groups - * 0-7, 8-9, 10-11, 12-14, 14-15, 16-17, 18-21, 21-* - * the following bits are set: - * - * 31 24 16 8 0 - * | | | | | - * oooooooo oo1oo1o1 o1o1o1o1 ooooooo1 - * - * A value of 0 means that the exchange does not support the extension for - * age-restriction. - */ -struct TALER_AgeMask -{ - uint32_t mask; -}; - -/** - * @brief Age restriction commitment of a coin. - */ -struct TALER_AgeHash -{ - /** - * The commitment is a SHA-256 hash code. - */ - struct GNUNET_ShortHashCode shash; -}; - /** * @brief Type of public keys for Taler coins. The same key material is used @@ -364,6 +333,29 @@ struct TALER_CoinSpendPrivateKeyP struct GNUNET_CRYPTO_EddsaPrivateKey eddsa_priv; }; +/** + * @brief Type of private keys for age commitment in coins. + */ +struct TALER_AgeCommitmentPrivateKeyP +{ + /** + * Taler uses EdDSA for coins when signing age verification attestation. + */ + struct GNUNET_CRYPTO_EddsaPrivateKey eddsa_priv; +}; + + +/** + * @brief Type of public keys for age commitment in coins. + */ +struct TALER_AgeCommitmentPublicKeyP +{ + /** + * Taler uses EdDSA for coins when signing age verification attestation. + */ + struct GNUNET_CRYPTO_EddsaPublicKey eddsa_pub; +}; + /** * @brief Type of signatures made with Taler coins. @@ -765,6 +757,46 @@ struct TALER_BlindedDenominationSignature }; +/* *************** Age Restriction *********************************** */ + +/* + * @brief Type of a list of age groups, represented as bit mask. + * + * The bits set in the mask mark the edges at the beginning of a next age + * group. F.e. for the age groups + * 0-7, 8-9, 10-11, 12-14, 14-15, 16-17, 18-21, 21-* + * the following bits are set: + * + * 31 24 16 8 0 + * | | | | | + * oooooooo oo1oo1o1 o1o1o1o1 ooooooo1 + * + * A value of 0 means that the exchange does not support the extension for + * age-restriction. + */ +struct TALER_AgeMask +{ + uint32_t mask; +}; + +/** + * @brief Age commitment of a coin. + */ +struct TALER_AgeCommitmentHash +{ + /** + * The commitment is a SHA-256 hash code. + */ + struct GNUNET_ShortHashCode shash; +}; + +extern const struct TALER_AgeCommitmentHash TALER_ZeroAgeCommitmentHash; +#define TALER_AgeCommitmentHash_isNullOrZero(ph) ((NULL == ph) || \ + (0 == memcmp (ph, \ + & \ + TALER_ZeroAgeCommitmentHash, \ + sizeof(struct \ + TALER_AgeCommitmentHash)))) /** * @brief Type of public signing keys for verifying blindly signed coins. @@ -944,9 +976,10 @@ struct TALER_CoinPublicInfo struct TALER_DenominationHash denom_pub_hash; /** - * Hash of the age commitment. + * Hash of the age commitment. If no age commitment was provided, it must be + * set to all zeroes. */ - struct TALER_AgeHash age_commitment_hash; + struct TALER_AgeCommitmentHash age_commitment_hash; /** * (Unblinded) signature over @e coin_pub with @e denom_pub, @@ -1117,7 +1150,7 @@ TALER_denom_sig_free (struct TALER_DenominationSignature *denom_sig); enum GNUNET_GenericReturnValue TALER_denom_blind (const struct TALER_DenominationPublicKey *dk, const union TALER_DenominationBlindingKeyP *coin_bks, - const struct TALER_AgeHash *age_commitment_hash, + const struct TALER_AgeCommitmentHash *age_commitment_hash, const struct TALER_CoinSpendPublicKeyP *coin_pub, const struct TALER_ExchangeWithdrawValues *alg_values, struct TALER_CoinPubHash *c_hash, @@ -1349,7 +1382,7 @@ TALER_withdraw_request_hash ( */ void TALER_coin_pub_hash (const struct TALER_CoinSpendPublicKeyP *coin_pub, - const struct TALER_AgeHash *age_commitment_hash, + const struct TALER_AgeCommitmentHash *age_commitment_hash, struct TALER_CoinPubHash *coin_h); @@ -1402,8 +1435,9 @@ struct TALER_FreshCoin struct TALER_CoinSpendPrivateKeyP coin_priv; /** - * FIXME-Oec: Age-verification vector, as pointer: Dyn alloc! + * Optional hash of an age commitment bound to this coin, maybe NULL. */ + const struct TALER_AgeCommitmentHash *h_age_commitment; }; @@ -1571,6 +1605,7 @@ TALER_planchet_blinding_secret_create ( * @param alg_values algorithm specific values * @param bks blinding secrets * @param coin_priv coin private key + * @param ach hash of age commitment to bind to this coin, maybe NULL * @param[out] c_hash set to the hash of the public key of the coin (needed later) * @param[out] pd set to the planchet detail for TALER_MERCHANT_tip_pickup() and * other withdraw operations, `pd->blinded_planchet.cipher` will be set @@ -1582,6 +1617,7 @@ TALER_planchet_prepare (const struct TALER_DenominationPublicKey *dk, const struct TALER_ExchangeWithdrawValues *alg_values, const union TALER_DenominationBlindingKeyP *bks, const struct TALER_CoinSpendPrivateKeyP *coin_priv, + const struct TALER_AgeCommitmentHash *ach, struct TALER_CoinPubHash *c_hash, struct TALER_PlanchetDetail *pd); @@ -1613,6 +1649,7 @@ TALER_planchet_detail_free (struct TALER_PlanchetDetail *pd); * @param blind_sig blind signature from the exchange * @param bks blinding key secret * @param coin_priv private key of the coin + * @param ach hash of age commitment that is bound to this coin, maybe NULL * @param c_hash hash of the coin's public key for verification of the signature * @param alg_values values obtained from the exchange for the withdrawal * @param[out] coin set to the details of the fresh coin @@ -1624,6 +1661,7 @@ TALER_planchet_to_coin ( const struct TALER_BlindedDenominationSignature *blind_sig, const union TALER_DenominationBlindingKeyP *bks, const struct TALER_CoinSpendPrivateKeyP *coin_priv, + const struct TALER_AgeCommitmentHash *ach, const struct TALER_CoinPubHash *c_hash, const struct TALER_ExchangeWithdrawValues *alg_values, struct TALER_FreshCoin *coin); @@ -2202,6 +2240,7 @@ TALER_wallet_account_setup_sign ( * @param deposit_fee the deposit fee we expect to pay * @param h_wire hash of the merchant’s account details * @param h_contract_terms hash of the contact of the merchant with the customer (further details are never disclosed to the exchange) + * @param h_age_commitment hash over the age commitment, if applicable to the denomination (maybe NULL) * @param h_extensions hash over the extensions * @param h_denom_pub hash of the coin denomination's public key * @param coin_priv coin’s private key @@ -2216,6 +2255,7 @@ TALER_wallet_deposit_sign ( const struct TALER_Amount *deposit_fee, const struct TALER_MerchantWireHash *h_wire, const struct TALER_PrivateContractHash *h_contract_terms, + const struct TALER_AgeCommitmentHash *h_age_commitment, const struct TALER_ExtensionContractHash *h_extensions, const struct TALER_DenominationHash *h_denom_pub, struct GNUNET_TIME_Timestamp wallet_timestamp, @@ -2232,6 +2272,7 @@ TALER_wallet_deposit_sign ( * @param deposit_fee the deposit fee we expect to pay * @param h_wire hash of the merchant’s account details * @param h_contract_terms hash of the contact of the merchant with the customer (further details are never disclosed to the exchange) + * @param h_age_commitment hash over the age commitment (maybe all zeroes, if not applicable to the denomination) * @param h_extensions hash over the extensions * @param h_denom_pub hash of the coin denomination's public key * @param wallet_timestamp timestamp when the contract was finalized, must not be too far in the future @@ -2247,6 +2288,7 @@ TALER_wallet_deposit_verify ( const struct TALER_Amount *deposit_fee, const struct TALER_MerchantWireHash *h_wire, const struct TALER_PrivateContractHash *h_contract_terms, + const struct TALER_AgeCommitmentHash *h_commitment_hash, const struct TALER_ExtensionContractHash *h_extensions, const struct TALER_DenominationHash *h_denom_pub, struct GNUNET_TIME_Timestamp wallet_timestamp, @@ -2283,6 +2325,7 @@ TALER_wallet_melt_sign ( * @param melt_fee the melt fee we expect to pay * @param rc refresh session we are committed to * @param h_denom_pub hash of the coin denomination's public key + * @param h_age_commitment hash of the age commitment (may be NULL) * @param coin_pub coin’s public key * @param coin_sig the signature made with purpose #TALER_SIGNATURE_WALLET_COIN_MELT * @return #GNUNET_OK if the signature is valid @@ -2293,6 +2336,7 @@ TALER_wallet_melt_verify ( const struct TALER_Amount *melt_fee, const struct TALER_RefreshCommitmentP *rc, const struct TALER_DenominationHash *h_denom_pub, + const struct TALER_AgeCommitmentHash *h_age_commitment, const struct TALER_CoinSpendPublicKeyP *coin_pub, const struct TALER_CoinSpendSignatureP *coin_sig); @@ -2321,6 +2365,7 @@ TALER_wallet_link_sign (const struct TALER_DenominationHash *h_denom_pub, * @param transfer_pub transfer public key * @param h_coin_ev hash of the coin envelope * @param old_coin_pub old coin key that the link signature is for + * @param h_age_commitment hash of age commitment. Maybe NULL, if not applicable. * @param coin_sig resulting signature * @return #GNUNET_OK if the signature is valid */ @@ -2330,6 +2375,7 @@ TALER_wallet_link_verify ( const struct TALER_TransferPublicKeyP *transfer_pub, const struct TALER_BlindedCoinHash *h_coin_ev, const struct TALER_CoinSpendPublicKeyP *old_coin_pub, + const struct TALER_AgeCommitmentHash *h_age_commitment, const struct TALER_CoinSpendSignatureP *coin_sig); @@ -3149,5 +3195,100 @@ TALER_exchange_offline_extension_config_hash_verify ( const struct TALER_MasterSignatureP *master_sig ); +/* + * @brief Representation of an age commitment: one public key per age group. + * + * The number of keys must be be the same as the number of bits set in the + * corresponding age mask. + */ +struct TALER_AgeCommitment +{ + + /* The age mask defines the age groups that were a parameter during the + * generation of this age commitment */ + struct TALER_AgeMask mask; + + /* The number of public keys, which must be the same as the number of + * groups in the mask. + */ + size_t num_pub; + + /* The list of #num_pub public keys. In must have same size as the number of + * age groups defined in the mask. + * + * A hash of this list is the hashed commitment that goes into FDC + * calculation during the withdraw and refresh operations for new coins. That + * way, the particular age commitment becomes mandatory and bound to a coin. + * + * The list has been allocated via GNUNET_malloc. + */ + struct TALER_AgeCommitmentPublicKeyP *pub; + + /* The number of private keys, which must be at most num_pub_keys. One minus + * this number corresponds to the largest age group that is supported with + * this age commitment. + */ + size_t num_priv; + + /* List of #num_priv private keys. + * + * Note that the list can be _smaller_ than the corresponding list of public + * keys. In that case, the wallet can sign off only for a subset of the age + * groups. + * + * The list has been allocated via GNUNET_malloc. + */ + struct TALER_AgeCommitmentPrivateKeyP *priv; +}; + +/* + * @brief Generates a hash of the public keys in the age commitment. + * + * @param commitment the age commitment - one public key per age group + * @param[out] hash resulting hash + */ +void +TALER_age_commitment_hash ( + const struct TALER_AgeCommitment *commitment, + struct TALER_AgeCommitmentHash *hash); + +/* + * @brief Generates an age commitent for the given age. + * + * @param mask The age mask the defines the age groups + * @param age The actual age for which an age commitment is generated + * @param seed The seed that goes into the key generation. MUST be choosen uniformly random. + * @param commitment[out] The generated age commitment, ->priv and ->pub allocated via GNUNET_malloc on success + * @return GNUNET_OK on success, GNUNET_SYSERR otherwise + */ +enum GNUNET_GenericReturnValue +TALER_age_restriction_commit ( + const struct TALER_AgeMask *mask, + const uint8_t age, + const uint32_t seed, + struct TALER_AgeCommitment *commitment); + +/* + * @brief Derives another, equivalent age commitment for a given one. + * + * @param orig Original age commitment + * @param seed Used to move the points on the elliptic curve in order to generate another, equivalent commitment. + * @param derived[out] The resulting age commitment, ->priv and ->pub allocated via GNUNET_malloc on success. + * @return GNUNET_OK on success, GNUNET_SYSERR otherwise + */ +enum GNUNET_GenericReturnValue +TALER_age_commitment_derive ( + const struct TALER_AgeCommitment *orig, + const uint32_t seed, + struct TALER_AgeCommitment *derived); + +/* + * @brief helper function to free memory inside a struct TALER_AgeCommitment + * @param cmt the commitment from which internal memory should be freed. Note + * that cmt itself is NOT freed! + */ +void +TALER_age_restriction_commitment_free_inside ( + struct TALER_AgeCommitment *cmt); #endif |