diff options
Diffstat (limited to 'src/util')
| -rw-r--r-- | src/util/crypto.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/src/util/crypto.c b/src/util/crypto.c index b803b960a..edc300878 100644 --- a/src/util/crypto.c +++ b/src/util/crypto.c @@ -163,6 +163,34 @@ TALER_transfer_decrypt (const struct TALER_EncryptedLinkSecretP *secret_enc, /** + * Given the coin and the transfer private keys, compute the + * transfer secret. (Technically, we only need one of the two + * private keys, but the caller currently trivially only has + * the two private keys, so we derive one of the public keys + * internally to this function.) + * + * @param coin_priv coin key + * @param trans_priv transfer private key + * @param[out] computed transfer secret + */ +void +TALER_link_derive_transfer_secret (const struct TALER_CoinSpendPrivateKeyP *coin_priv, + const struct TALER_TransferPrivateKeyP *trans_priv, + struct TALER_TransferSecretP *ts) +{ + struct TALER_CoinSpendPublicKeyP coin_pub; + + GNUNET_CRYPTO_eddsa_key_get_public (&coin_priv->eddsa_priv, + &coin_pub.eddsa_pub); + GNUNET_assert (GNUNET_OK == + GNUNET_CRYPTO_ecdh_eddsa (&trans_priv->ecdhe_priv, + &coin_pub.eddsa_pub, + &ts->key)); + +} + + +/** * Use the @a trans_sec (from ECDHE) to encrypt the @a secret * to obtain the @a secret_enc. * |