Dima Barsky reported a problem with GnuTLS-enabled libcurl in bug report

#1334338 (http://curl.haxx.se/bug/view.cgi?id=1334338). When reading an SSL
  stream from a server and the server requests a "rehandshake", the current
  code simply returns this as an error. I have no good way to test this, but
  I've added a crude attempt of dealing with this situation slightly better -
  it makes a blocking handshake if this happens. Done like this because fixing
  this the "proper" way (that would handshake asynchronously) will require
  quite some work and I really need a good way to test this to do such a
  change.
This commit is contained in:
Daniel Stenberg 2005-10-22 21:05:07 +00:00
parent 1a1ab2e2e8
commit c890149c8c
2 changed files with 92 additions and 55 deletions

11
CHANGES
View File

@ -8,6 +8,17 @@
Daniel (22 October 2005)
- Dima Barsky reported a problem with GnuTLS-enabled libcurl in bug report
#1334338 (http://curl.haxx.se/bug/view.cgi?id=1334338). When reading an SSL
stream from a server and the server requests a "rehandshake", the current
code simply returns this as an error. I have no good way to test this, but
I've added a crude attempt of dealing with this situation slightly better -
it makes a blocking handshake if this happens. Done like this because fixing
this the "proper" way (that would handshake asynchronously) will require
quite some work and I really need a good way to test this to do such a
change.
Daniel (21 October 2005)
- "Ofer" reported a problem when libcurl re-used a connection and failed to do
it, it could then accidentally actually crash. Presumably, this concerns FTP

View File

@ -110,6 +110,72 @@ static void showtime(struct SessionHandle *data,
infof(data, "%s", data->state.buffer);
}
/* this function does a BLOCKING SSL/TLS (re-)handshake */
static CURLcode handshake(struct connectdata *conn,
gnutls_session session,
int sockindex,
bool duringconnect)
{
struct SessionHandle *data = conn->data;
int rc;
do {
rc = gnutls_handshake(session);
if((rc == GNUTLS_E_AGAIN) || (rc == GNUTLS_E_INTERRUPTED)) {
long timeout_ms = DEFAULT_CONNECT_TIMEOUT;
long has_passed;
if(duringconnect && data->set.connecttimeout)
timeout_ms = data->set.connecttimeout*1000;
if(data->set.timeout) {
/* get the strictest timeout of the ones converted to milliseconds */
if((data->set.timeout*1000) < timeout_ms)
timeout_ms = data->set.timeout*1000;
}
/* Evaluate in milliseconds how much time that has passed */
has_passed = Curl_tvdiff(Curl_tvnow(), data->progress.t_startsingle);
/* subtract the passed time */
timeout_ms -= has_passed;
if(timeout_ms < 0) {
/* a precaution, no need to continue if time already is up */
failf(data, "SSL connection timeout");
return CURLE_OPERATION_TIMEOUTED;
}
rc = Curl_select(conn->sock[sockindex],
conn->sock[sockindex], (int)timeout_ms);
if(rc > 0)
/* reabable or writable, go loop*/
continue;
else if(0 == rc) {
/* timeout */
failf(data, "SSL connection timeout");
return CURLE_OPERATION_TIMEDOUT;
}
else {
/* anything that gets here is fatally bad */
failf(data, "select on SSL socket, errno: %d", Curl_ourerrno());
return CURLE_SSL_CONNECT_ERROR;
}
}
else
break;
} while(1);
if (rc < 0) {
failf(data, "gnutls_handshake() failed: %d", rc);
/* gnutls_perror(ret); */
return CURLE_SSL_CONNECT_ERROR;
}
return CURLE_OK;
}
/*
* This function is called after the TCP connect has completed. Setup the TLS
* layer and do all necessary magic.
@ -206,61 +272,10 @@ Curl_gtls_connect(struct connectdata *conn,
infof (data, "SSL re-using session ID\n");
}
do {
rc = gnutls_handshake(session);
if((rc == GNUTLS_E_AGAIN) || (rc == GNUTLS_E_INTERRUPTED)) {
long timeout_ms;
long has_passed;
if(data->set.timeout || data->set.connecttimeout) {
/* get the most strict timeout of the ones converted to milliseconds */
if(data->set.timeout &&
(data->set.timeout>data->set.connecttimeout))
timeout_ms = data->set.timeout*1000;
else
timeout_ms = data->set.connecttimeout*1000;
}
else
timeout_ms = DEFAULT_CONNECT_TIMEOUT;
/* Evaluate in milliseconds how much time that has passed */
has_passed = Curl_tvdiff(Curl_tvnow(), data->progress.t_startsingle);
/* subtract the passed time */
timeout_ms -= has_passed;
if(timeout_ms < 0) {
/* a precaution, no need to continue if time already is up */
failf(data, "SSL connection timeout");
return CURLE_OPERATION_TIMEOUTED;
}
rc = Curl_select(conn->sock[sockindex],
conn->sock[sockindex], (int)timeout_ms);
if(rc > 0)
/* reabable or writable, go loop*/
continue;
else if(0 == rc) {
/* timeout */
failf(data, "SSL connection timeout");
return CURLE_OPERATION_TIMEDOUT;
}
else {
/* anything that gets here is fatally bad */
failf(data, "select on SSL socket, errno: %d", Curl_ourerrno());
return CURLE_SSL_CONNECT_ERROR;
}
}
else
break;
} while(1);
if (rc < 0) {
failf(data, "gnutls_handshake() failed: %d", rc);
/* gnutls_perror(ret); */
return CURLE_SSL_CONNECT_ERROR;
}
rc = handshake(conn, session, sockindex, TRUE);
if(rc)
/* handshake() sets its own error message with failf() */
return rc;
/* This function will return the peer's raw certificate (chain) as sent by
the peer. These certificates are in raw format (DER encoded for
@ -467,6 +482,17 @@ ssize_t Curl_gtls_recv(struct connectdata *conn, /* connection data */
return -1;
}
if(ret == GNUTLS_E_REHANDSHAKE) {
/* BLOCKING call, this is bad but a work-around for now. Fixing this "the
proper way" takes a whole lot of work. */
CURLcode rc = handshake(conn, conn->ssl[num].session, num, FALSE);
if(rc)
/* handshake() writes error message on its own */
return rc;
*wouldblock = TRUE; /* then return as if this was a wouldblock */
return -1;
}
*wouldblock = FALSE;
if (!ret) {
failf(conn->data, "Peer closed the TLS connection");