/**
* Check if a signature is valid. This API is used by the GNS Block
* to validate signatures received from the network.
*
* @param block block to verify
* @return #GNUNET_OK if the signature is valid
*/
int
GNUNET_GNSRECORD_block_verify (const struct GNUNET_GNSRECORD_Block *block)
{
return GNUNET_CRYPTO_ecdsa_verify (GNUNET_SIGNATURE_PURPOSE_GNS_RECORD_SIGN,
&block->purpose,
&block->signature,
&block->derived_key);
}
/**
* Function to handle a ring message incoming over cadet
*
* @param cls closure, NULL
* @param channel the channel over which the message arrived
* @param channel_ctx the channel context, can be NULL
* or point to the `struct Channel`
* @param message the incoming message
* @return #GNUNET_OK
*/
static int
handle_cadet_ring_message (void *cls,
struct GNUNET_CADET_Channel *channel,
void **channel_ctx,
const struct GNUNET_MessageHeader *message)
{
struct Channel *ch = *channel_ctx;
struct Line *line = ch->line;
const struct CadetPhoneRingMessage *msg;
struct GNUNET_MQ_Envelope *env;
struct ClientPhoneRingMessage *cring;
struct CadetPhoneRingInfoPS rs;
msg = (const struct CadetPhoneRingMessage *) message;
rs.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_CONVERSATION_RING);
rs.purpose.size = htonl (sizeof (struct CadetPhoneRingInfoPS));
rs.line_port = line->line_port;
rs.target_peer = my_identity;
rs.expiration_time = msg->expiration_time;
if (GNUNET_OK !=
GNUNET_CRYPTO_ecdsa_verify (GNUNET_SIGNATURE_PURPOSE_CONVERSATION_RING,
&rs.purpose,
&msg->signature,
&msg->caller_id))
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
if (0 == GNUNET_TIME_absolute_get_remaining (GNUNET_TIME_absolute_ntoh (msg->expiration_time)).rel_value_us)
{
/* ancient call, replay? */
GNUNET_break_op (0);
/* Note that our reliance on time here is awkward; better would be
to use a more complex challenge-response protocol against
replay attacks. Left for future work ;-). */
return GNUNET_SYSERR;
}
if (CS_CALLEE_INIT != ch->status)
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
GNUNET_CADET_receive_done (channel);
ch->status = CS_CALLEE_RINGING;
env = GNUNET_MQ_msg (cring,
GNUNET_MESSAGE_TYPE_CONVERSATION_CS_PHONE_RING);
cring->cid = ch->cid;
cring->caller_id = msg->caller_id;
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Sending RING message to client. CID is %u\n",
(unsigned int) ch->cid);
GNUNET_MQ_send (line->mq,
env);
return GNUNET_OK;
}
