diff options
Diffstat (limited to 'src/util/crypto.c')
| -rw-r--r-- | src/util/crypto.c | 357 |
1 files changed, 63 insertions, 294 deletions
diff --git a/src/util/crypto.c b/src/util/crypto.c index 3200e2a05..771744c7e 100644 --- a/src/util/crypto.c +++ b/src/util/crypto.c @@ -73,92 +73,32 @@ TALER_gcrypt_init () /** - * Derive symmetric key material for refresh operations from - * a given shared secret for link decryption. - * - * @param secret the shared secret - * @param[out] iv set to initialization vector - * @param[out] skey set to session key - */ -static void -derive_refresh_key (const struct TALER_LinkSecretP *secret, - struct GNUNET_CRYPTO_SymmetricInitializationVector *iv, - struct GNUNET_CRYPTO_SymmetricSessionKey *skey) -{ - static const char ctx_key[] = "taler-link-skey"; - static const char ctx_iv[] = "taler-link-iv"; - - GNUNET_assert (GNUNET_YES == - GNUNET_CRYPTO_kdf (skey, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey), - ctx_key, strlen (ctx_key), - secret, sizeof (struct TALER_LinkSecretP), - NULL, 0)); - GNUNET_assert (GNUNET_YES == - GNUNET_CRYPTO_kdf (iv, sizeof (struct GNUNET_CRYPTO_SymmetricInitializationVector), - ctx_iv, strlen (ctx_iv), - secret, sizeof (struct TALER_LinkSecretP), - NULL, 0)); -} - - -/** - * Derive symmetric key material for refresh operations from - * a given shared secret for key decryption. - * - * @param secret the shared secret - * @param[out] iv set to initialization vector - * @param[out] skey set to session key - */ -static void -derive_transfer_key (const struct TALER_TransferSecretP *secret, - struct GNUNET_CRYPTO_SymmetricInitializationVector *iv, - struct GNUNET_CRYPTO_SymmetricSessionKey *skey) -{ - static const char ctx_key[] = "taler-transfer-skey"; - static const char ctx_iv[] = "taler-transfer-iv"; - - GNUNET_assert (GNUNET_YES == - GNUNET_CRYPTO_kdf (skey, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey), - ctx_key, strlen (ctx_key), - secret, sizeof (struct TALER_TransferSecretP), - NULL, 0)); - GNUNET_assert (GNUNET_YES == - GNUNET_CRYPTO_kdf (iv, sizeof (struct GNUNET_CRYPTO_SymmetricInitializationVector), - ctx_iv, strlen (ctx_iv), - secret, sizeof (struct TALER_TransferSecretP), - NULL, 0)); -} - - -/** - * Use the @a trans_sec (from ECDHE) to decrypt the @a secret_enc - * to obtain the @a secret to decrypt the linkage data. + * Check if a coin is valid; that is, whether the denomination key exists, + * is not expired, and the signature is correct. * - * @param secret_enc encrypted secret - * @param trans_sec transfer secret - * @param secret shared secret for refresh link decryption - * @return #GNUNET_OK on success + * @param coin_public_info the coin public info to check for validity + * @return #GNUNET_YES if the coin is valid, + * #GNUNET_NO if it is invalid + * #GNUNET_SYSERROR if an internal error occured */ int -TALER_transfer_decrypt (const struct TALER_EncryptedLinkSecretP *secret_enc, - const struct TALER_TransferSecretP *trans_sec, - struct TALER_LinkSecretP *secret) +TALER_test_coin_valid (const struct TALER_CoinPublicInfo *coin_public_info) { - struct GNUNET_CRYPTO_SymmetricInitializationVector iv; - struct GNUNET_CRYPTO_SymmetricSessionKey skey; - ssize_t s; + struct GNUNET_HashCode c_hash; - GNUNET_assert (sizeof (struct TALER_EncryptedLinkSecretP) == - sizeof (struct TALER_LinkSecretP)); - derive_transfer_key (trans_sec, &iv, &skey); - s = GNUNET_CRYPTO_symmetric_decrypt (secret_enc, - sizeof (struct TALER_LinkSecretP), - &skey, - &iv, - secret); - if (sizeof (struct TALER_LinkSecretP) != s) - return GNUNET_SYSERR; - return GNUNET_OK; + GNUNET_CRYPTO_hash (&coin_public_info->coin_pub, + sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey), + &c_hash); + if (GNUNET_OK != + GNUNET_CRYPTO_rsa_verify (&c_hash, + coin_public_info->denom_sig.rsa_signature, + coin_public_info->denom_pub.rsa_public_key)) + { + GNUNET_log (GNUNET_ERROR_TYPE_WARNING, + "coin signature is invalid\n"); + return GNUNET_NO; + } + return GNUNET_YES; } @@ -191,244 +131,73 @@ TALER_link_derive_transfer_secret (const struct TALER_CoinSpendPrivateKeyP *coin /** - * Use the @a trans_sec (from ECDHE) to encrypt the @a secret - * to obtain the @a secret_enc. - * - * @param secret shared secret for refresh link decryption - * @param trans_sec transfer secret - * @param[out] secret_enc encrypted secret - * @return #GNUNET_OK on success - */ -int -TALER_transfer_encrypt (const struct TALER_LinkSecretP *secret, - const struct TALER_TransferSecretP *trans_sec, - struct TALER_EncryptedLinkSecretP *secret_enc) -{ - struct GNUNET_CRYPTO_SymmetricInitializationVector iv; - struct GNUNET_CRYPTO_SymmetricSessionKey skey; - ssize_t s; - - GNUNET_assert (sizeof (struct TALER_EncryptedLinkSecretP) == - sizeof (struct TALER_LinkSecretP)); - derive_transfer_key (trans_sec, &iv, &skey); - s = GNUNET_CRYPTO_symmetric_encrypt (secret, - sizeof (struct TALER_LinkSecretP), - &skey, - &iv, - secret_enc); - if (sizeof (struct TALER_LinkSecretP) != s) - return GNUNET_SYSERR; - return GNUNET_OK; -} - - -/** - * Decrypt refresh link information. - * - * @param input encrypted refresh link data - * @param secret shared secret to use for decryption - * @param[out] output where to write decrypted data - */ -void -TALER_refresh_decrypt (const struct TALER_RefreshLinkEncryptedP *input, - const struct TALER_LinkSecretP *secret, - struct TALER_RefreshLinkDecryptedP *output) -{ - struct GNUNET_CRYPTO_SymmetricInitializationVector iv; - struct GNUNET_CRYPTO_SymmetricSessionKey skey; - - derive_refresh_key (secret, &iv, &skey); - GNUNET_assert (sizeof (struct TALER_RefreshLinkEncryptedP) == - sizeof (struct TALER_RefreshLinkDecryptedP)); - GNUNET_assert (sizeof (struct TALER_RefreshLinkEncryptedP) == - GNUNET_CRYPTO_symmetric_decrypt (input, - sizeof (struct TALER_RefreshLinkEncryptedP), - &skey, - &iv, - output)); -} - - -/** - * Encrypt refresh link information. - * - * @param input plaintext refresh link data - * @param secret shared secret to use for encryption - * @param[out] output where to write encrypted link data - */ -void -TALER_refresh_encrypt (const struct TALER_RefreshLinkDecryptedP *input, - const struct TALER_LinkSecretP *secret, - struct TALER_RefreshLinkEncryptedP *output) -{ - struct GNUNET_CRYPTO_SymmetricInitializationVector iv; - struct GNUNET_CRYPTO_SymmetricSessionKey skey; - - derive_refresh_key (secret, &iv, &skey); - GNUNET_assert (sizeof (struct TALER_RefreshLinkEncryptedP) == - sizeof (struct TALER_RefreshLinkDecryptedP)); - GNUNET_assert (sizeof (struct TALER_RefreshLinkEncryptedP) == - GNUNET_CRYPTO_symmetric_encrypt (input, - sizeof (struct TALER_RefreshLinkDecryptedP), - &skey, - &iv, - output)); -} - - -/** - * Check if a coin is valid; that is, whether the denomination key exists, - * is not expired, and the signature is correct. - * - * @param coin_public_info the coin public info to check for validity - * @return #GNUNET_YES if the coin is valid, - * #GNUNET_NO if it is invalid - * #GNUNET_SYSERROR if an internal error occured - */ -int -TALER_test_coin_valid (const struct TALER_CoinPublicInfo *coin_public_info) -{ - struct GNUNET_HashCode c_hash; - - GNUNET_CRYPTO_hash (&coin_public_info->coin_pub, - sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey), - &c_hash); - if (GNUNET_OK != - GNUNET_CRYPTO_rsa_verify (&c_hash, - coin_public_info->denom_sig.rsa_signature, - coin_public_info->denom_pub.rsa_public_key)) - { - GNUNET_log (GNUNET_ERROR_TYPE_WARNING, - "coin signature is invalid\n"); - return GNUNET_NO; - } - return GNUNET_YES; -} - - -/** * Decrypt the shared @a secret from the information in the - * encrypted link secret @e secret_enc using the transfer - * private key and the coin's public key. + * @a trans_priv and @a coin_pub. * - * @param secret_enc encrypted link secret * @param trans_priv transfer private key * @param coin_pub coin public key * @param[out] secret set to the shared secret - * @return #GNUNET_OK on success, #GNUNET_SYSERR on error */ -int -TALER_link_decrypt_secret (const struct TALER_EncryptedLinkSecretP *secret_enc, - const struct TALER_TransferPrivateKeyP *trans_priv, - const struct TALER_CoinSpendPublicKeyP *coin_pub, - struct TALER_LinkSecretP *secret) +void +TALER_link_reveal_transfer_secret (const struct TALER_TransferPrivateKeyP *trans_priv, + const struct TALER_CoinSpendPublicKeyP *coin_pub, + struct TALER_TransferSecretP *transfer_secret) { - struct TALER_TransferSecretP transfer_secret; - - if (GNUNET_OK != - GNUNET_CRYPTO_ecdh_eddsa (&trans_priv->ecdhe_priv, - &coin_pub->eddsa_pub, - &transfer_secret.key)) - { - GNUNET_break (0); - return GNUNET_SYSERR; - } - if (GNUNET_OK != - TALER_transfer_decrypt (secret_enc, - &transfer_secret, - secret)) - { - GNUNET_break (0); - return GNUNET_SYSERR; - } - return GNUNET_OK; + GNUNET_assert (GNUNET_OK == + GNUNET_CRYPTO_ecdh_eddsa (&trans_priv->ecdhe_priv, + &coin_pub->eddsa_pub, + &transfer_secret->key)); } /** * Decrypt the shared @a secret from the information in the - * encrypted link secret @e secret_enc using the transfer - * public key and the coin's private key. + * @a trans_priv and @a coin_pub. * - * @param secret_enc encrypted link secret - * @param trans_pub transfer public key - * @param coin_priv coin private key + * @param trans_pub transfer private key + * @param coin_priv coin public key * @param[out] secret set to the shared secret - * @return #GNUNET_OK on success, #GNUNET_SYSERR on error */ -int -TALER_link_decrypt_secret2 (const struct TALER_EncryptedLinkSecretP *secret_enc, - const struct TALER_TransferPublicKeyP *trans_pub, - const struct TALER_CoinSpendPrivateKeyP *coin_priv, - struct TALER_LinkSecretP *secret) +void +TALER_link_recover_transfer_secret (const struct TALER_TransferPublicKeyP *trans_pub, + const struct TALER_CoinSpendPrivateKeyP *coin_priv, + struct TALER_TransferSecretP *transfer_secret) { - struct TALER_TransferSecretP transfer_secret; - - if (GNUNET_OK != - GNUNET_CRYPTO_eddsa_ecdh (&coin_priv->eddsa_priv, - &trans_pub->ecdhe_pub, - &transfer_secret.key)) - { - GNUNET_break (0); - return GNUNET_SYSERR; - } - if (GNUNET_OK != - TALER_transfer_decrypt (secret_enc, - &transfer_secret, - secret)) - { - GNUNET_break (0); - return GNUNET_SYSERR; - } - return GNUNET_OK; + GNUNET_assert (GNUNET_OK == + GNUNET_CRYPTO_eddsa_ecdh (&coin_priv->eddsa_priv, + &trans_pub->ecdhe_pub, + &transfer_secret->key)); } /** - * Encrypt the shared @a secret to generate the encrypted link secret. - * Also creates the transfer key. + * Setup information for a fresh coin. * - * @param secret link secret to encrypt - * @param coin_pub coin public key - * @param[out] trans_priv set to transfer private key - * @param[out] trans_pub set to transfer public key - * @param[out] secret_enc set to the encryptd @a secret - * @return #GNUNET_OK on success, #GNUNET_SYSERR on error + * @param secret_seed seed to use for KDF to derive coin keys + * @param coin_num_salt number of the coin to include in KDF + * @param[out] fc value to initialize */ -int -TALER_link_encrypt_secret (const struct TALER_LinkSecretP *secret, - const struct TALER_CoinSpendPublicKeyP *coin_pub, - struct TALER_TransferPrivateKeyP *trans_priv, - struct TALER_TransferPublicKeyP *trans_pub, - struct TALER_EncryptedLinkSecretP *secret_enc) +void +TALER_setup_fresh_coin (const struct TALER_TransferSecretP *secret_seed, + unsigned int coin_num_salt, + struct TALER_FreshCoinP *fc) { - struct TALER_TransferSecretP transfer_secret; - struct GNUNET_CRYPTO_EcdhePrivateKey *pk; + uint32_t be_salt = htonl (coin_num_salt); - pk = GNUNET_CRYPTO_ecdhe_key_create (); - if (GNUNET_OK != - GNUNET_CRYPTO_ecdh_eddsa (pk, - &coin_pub->eddsa_pub, - &transfer_secret.key)) - { - GNUNET_break (0); - GNUNET_free (pk); - return GNUNET_SYSERR; - } - if (GNUNET_OK != - TALER_transfer_encrypt (secret, - &transfer_secret, - secret_enc)) - { - GNUNET_break (0); - return GNUNET_SYSERR; - } - trans_priv->ecdhe_priv = *pk; - GNUNET_CRYPTO_ecdhe_key_get_public (pk, - &trans_pub->ecdhe_pub); - GNUNET_free (pk); - return GNUNET_OK; + GNUNET_assert (GNUNET_OK == + GNUNET_CRYPTO_kdf (fc, + sizeof (*fc), + secret_seed, + sizeof (*secret_seed), + &be_salt, + sizeof (be_salt), + "taler-coin-derivation", + strlen ("taler-coin-derivation"), + NULL, 0)); + /* FIXME: twiddle the bits of the private key */ } + + /* end of crypto.c */ |