moving core refresh crypto logic to util -- towards fixing #3777

This commit is contained in:
Christian Grothoff 2015-04-15 18:12:21 +02:00
parent ad4759b46a
commit 97e403bb66
4 changed files with 136 additions and 27 deletions

View File

@ -423,6 +423,43 @@ struct TALER_RefreshLinkEncrypted
};
/**
* 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.
*
* @param secret_enc encrypted link secret
* @param transfer_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 union TALER_CoinSpendPublicKeyP *coin_pub,
struct TALER_LinkSecretP *secret);
/**
* Encrypt the shared @a secret to generate the encrypted link secret.
* Also creates the transfer key.
*
* @param secret link secret to encrypt
* @param coin_pub coin public key
* @param transfer_priv[out] set to transfer private key
* @param transfer_pub[out] set to transfer public key
* @param[out] secret_enc set to the encryptd @a secret
* @return #GNUNET_OK on success, #GNUNET_SYSERR on error
*/
int
TALER_link_encrypt_secret (const struct TALER_LinkSecretP *secret,
const union TALER_CoinSpendPublicKeyP *coin_pub,
struct TALER_TransferPrivateKeyP *trans_priv,
struct TALER_TransferPublicKeyP *trans_pub,
struct TALER_EncryptedLinkSecretP *secret_enc);
/**
* Use the @a trans_sec (from ECDHE) to decrypt the @a secret_enc
* to obtain the @a secret to decrypt the linkage data.

View File

@ -849,7 +849,6 @@ check_commitment (struct MHD_Connection *connection,
for (j = 0; j < num_oldcoins; j++)
{
struct TALER_TransferSecretP transfer_secret;
struct TALER_LinkSecretP shared_secret;
struct TALER_TransferPublicKeyP transfer_pub_check;
@ -871,32 +870,18 @@ check_commitment (struct MHD_Connection *connection,
"transfer key");
}
/* We're converting key types here, which is not very nice
* but necessary and harmless (keys will be thrown away later). */
if (GNUNET_OK !=
GNUNET_CRYPTO_ecc_ecdh (&transfer_privs[j].ecdhe_priv,
&melts[j].coin.coin_pub.ecdhe_pub,
&transfer_secret.key))
{
GNUNET_break (0);
GNUNET_free (commit_links);
return (MHD_YES == TMH_RESPONSE_reply_internal_error (connection,
"ECDH error"))
? GNUNET_NO : GNUNET_SYSERR;
}
if (GNUNET_OK !=
TALER_transfer_decrypt (&commit_links[j].shared_secret_enc,
&transfer_secret,
&shared_secret))
{
GNUNET_break (0);
TALER_link_decrypt_secret (&commit_links[j].shared_secret_enc,
&transfer_privs[j],
&melts[j].coin.coin_pub,
&shared_secret))
{
GNUNET_free (commit_links);
return (MHD_YES ==
TMH_RESPONSE_reply_internal_error (connection,
"Decryption error"))
? GNUNET_NO : GNUNET_SYSERR;
TMH_RESPONSE_reply_internal_error (connection,
"Transfer secret decryption error"))
? GNUNET_NO : GNUNET_SYSERR;
}
if (GNUNET_NO == secret_initialized)
{
secret_initialized = GNUNET_YES;

View File

@ -783,9 +783,9 @@ handle_refresh_reveal_json (struct MHD_Connection *connection,
res = (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES;
else
res = TMH_DB_execute_refresh_reveal (connection,
session_hash,
num_oldcoins,
transfer_privs);
session_hash,
num_oldcoins,
transfer_privs);
for (i = 0; i < TALER_CNC_KAPPA - 1; i++)
GNUNET_free (transfer_privs[i]);
return res;

View File

@ -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
@ -333,4 +333,91 @@ TALER_test_coin_valid (const struct TALER_CoinPublicInfo *coin_public_info)
}
/**
* 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.
*
* @param secret_enc encrypted link secret
* @param transfer_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 union TALER_CoinSpendPublicKeyP *coin_pub,
struct TALER_LinkSecretP *secret)
{
struct TALER_TransferSecretP transfer_secret;
if (GNUNET_OK !=
GNUNET_CRYPTO_ecc_ecdh (&trans_priv->ecdhe_priv,
&coin_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;
}
/**
* Encrypt the shared @a secret to generate the encrypted link secret.
* Also creates the transfer key.
*
* @param secret link secret to encrypt
* @param coin_pub coin public key
* @param transfer_priv[out] set to transfer private key
* @param transfer_pub[out] set to transfer public key
* @param[out] secret_enc set to the encryptd @a secret
* @return #GNUNET_OK on success, #GNUNET_SYSERR on error
*/
int
TALER_link_encrypt_secret (const struct TALER_LinkSecretP *secret,
const union TALER_CoinSpendPublicKeyP *coin_pub,
struct TALER_TransferPrivateKeyP *trans_priv,
struct TALER_TransferPublicKeyP *trans_pub,
struct TALER_EncryptedLinkSecretP *secret_enc)
{
struct TALER_TransferSecretP transfer_secret;
struct GNUNET_CRYPTO_EcdhePrivateKey *pk;
pk = GNUNET_CRYPTO_ecdhe_key_create ();
if (GNUNET_OK !=
GNUNET_CRYPTO_ecc_ecdh (pk,
&coin_pub->ecdhe_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;
}
/* end of crypto.c */