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From 245feaa0827d1f68168c8512aee4102f0d6c4155 Mon Sep 17 00:00:00 2001
From: Kamil Dudka <kdudka@redhat.com>
Date: Thu, 17 Apr 2014 13:12:59 +0200
Subject: [PATCH 1/3] nss: split Curl_nss_connect() into 4 functions

[upstream commit a43bba3a34ed8912c4ca10f213590d1998ba0d29]

Signed-off-by: Kamil Dudka <kdudka@redhat.com>
---
 lib/nss.c |  134 +++++++++++++++++++++++++++++++++++++++++++------------------
 1 files changed, 95 insertions(+), 39 deletions(-)

diff --git a/lib/nss.c b/lib/nss.c
index 2d4bf9e..b21daf0 100644
--- a/lib/nss.c
+++ b/lib/nss.c
@@ -1172,9 +1172,62 @@ static CURLcode nss_load_ca_certificates(struct connectdata *conn,
   return CURLE_OK;
 }
 
-CURLcode Curl_nss_connect(struct connectdata *conn, int sockindex)
+static CURLcode nss_fail_connect(struct ssl_connect_data *connssl,
+                                 struct SessionHandle *data,
+                                 CURLcode curlerr)
 {
+  SSLVersionRange sslver;
   PRErrorCode err = 0;
+
+  /* reset the flag to avoid an infinite loop */
+  data->state.ssl_connect_retry = FALSE;
+
+  if(is_nss_error(curlerr)) {
+    /* read NSPR error code */
+    err = PR_GetError();
+    if(is_cc_error(err))
+      curlerr = CURLE_SSL_CERTPROBLEM;
+
+    /* print the error number and error string */
+    infof(data, "NSS error %d (%s)\n", err, nss_error_to_name(err));
+
+    /* print a human-readable message describing the error if available */
+    nss_print_error_message(data, err);
+  }
+
+  /* cleanup on connection failure */
+  Curl_llist_destroy(connssl->obj_list, NULL);
+  connssl->obj_list = NULL;
+
+  if((SSL_VersionRangeGet(connssl->handle, &sslver) == SECSuccess)
+      && (sslver.min == SSL_LIBRARY_VERSION_3_0)
+      && (sslver.max == SSL_LIBRARY_VERSION_TLS_1_0)
+      && isTLSIntoleranceError(err)) {
+    /* schedule reconnect through Curl_retry_request() */
+    data->state.ssl_connect_retry = TRUE;
+    infof(data, "Error in TLS handshake, trying SSLv3...\n");
+    return CURLE_OK;
+  }
+
+  return curlerr;
+}
+
+/* Switch the SSL socket into non-blocking mode. */
+static CURLcode nss_set_nonblock(struct ssl_connect_data *connssl,
+                                 struct SessionHandle *data)
+{
+  static PRSocketOptionData sock_opt;
+  sock_opt.option = PR_SockOpt_Nonblocking;
+  sock_opt.value.non_blocking = PR_TRUE;
+
+  if(PR_SetSocketOption(connssl->handle, &sock_opt) != PR_SUCCESS)
+    return nss_fail_connect(connssl, data, CURLE_SSL_CONNECT_ERROR);
+
+  return CURLE_OK;
+}
+
+static CURLcode nss_setup_connect(struct connectdata *conn, int sockindex)
+{
   PRFileDesc *model = NULL;
   PRBool ssl2 = PR_FALSE;
   PRBool ssl3 = PR_FALSE;
@@ -1186,9 +1239,6 @@ CURLcode Curl_nss_connect(struct connectdata *conn, int sockindex)
   struct ssl_connect_data *connssl = &conn->ssl[sockindex];
   CURLcode curlerr;
   const int *cipher_to_enable;
-  PRSocketOptionData sock_opt;
-  long time_left;
-  PRUint32 timeout;
 
   if(connssl->state == ssl_connection_complete)
     return CURLE_OK;
@@ -1391,16 +1441,32 @@ CURLcode Curl_nss_connect(struct connectdata *conn, int sockindex)
 
   SSL_SetURL(connssl->handle, conn->host.name);
 
+  return CURLE_OK;
+
+error:
+  if(model)
+    PR_Close(model);
+
+  return nss_fail_connect(connssl, data, curlerr);
+}
+
+static CURLcode nss_do_connect(struct connectdata *conn, int sockindex)
+{
+  struct ssl_connect_data *connssl = &conn->ssl[sockindex];
+  struct SessionHandle *data = conn->data;
+  CURLcode curlerr = CURLE_SSL_CONNECT_ERROR;
+  PRUint32 timeout;
+
   /* check timeout situation */
-  time_left = Curl_timeleft(data, NULL, TRUE);
+  const long time_left = Curl_timeleft(data, NULL, TRUE);
   if(time_left < 0L) {
     failf(data, "timed out before SSL handshake");
     curlerr = CURLE_OPERATION_TIMEDOUT;
     goto error;
   }
-  timeout = PR_MillisecondsToInterval((PRUint32) time_left);
 
   /* Force the handshake now */
+  timeout = PR_MillisecondsToInterval((PRUint32) time_left);
   if(SSL_ForceHandshakeWithTimeout(connssl->handle, timeout) != SECSuccess) {
     if(conn->data->set.ssl.certverifyresult == SSL_ERROR_BAD_CERT_DOMAIN)
       curlerr = CURLE_PEER_FAILED_VERIFICATION;
@@ -1409,12 +1475,6 @@ CURLcode Curl_nss_connect(struct connectdata *conn, int sockindex)
     goto error;
   }
 
-  /* switch the SSL socket into non-blocking mode */
-  sock_opt.option = PR_SockOpt_Nonblocking;
-  sock_opt.value.non_blocking = PR_TRUE;
-  if(PR_SetSocketOption(connssl->handle, &sock_opt) != PR_SUCCESS)
-    goto error;
-
   connssl->state = ssl_connection_complete;
   conn->recv[sockindex] = nss_recv;
   conn->send[sockindex] = nss_send;
@@ -1442,40 +1502,36 @@ CURLcode Curl_nss_connect(struct connectdata *conn, int sockindex)
 
   return CURLE_OK;
 
-  error:
-  /* reset the flag to avoid an infinite loop */
-  data->state.ssl_connect_retry = FALSE;
+error:
+  return nss_fail_connect(connssl, data, curlerr);
+}
 
-  if(is_nss_error(curlerr)) {
-    /* read NSPR error code */
-    err = PR_GetError();
-    if(is_cc_error(err))
-      curlerr = CURLE_SSL_CERTPROBLEM;
+CURLcode Curl_nss_connect(struct connectdata *conn, int sockindex)
+{
+  struct ssl_connect_data *connssl = &conn->ssl[sockindex];
+  struct SessionHandle *data = conn->data;
+  CURLcode rv;
 
-    /* print the error number and error string */
-    infof(data, "NSS error %d (%s)\n", err, nss_error_to_name(err));
+  rv = nss_setup_connect(conn, sockindex);
+  if(rv)
+    return rv;
 
-    /* print a human-readable message describing the error if available */
-    nss_print_error_message(data, err);
+  rv = nss_do_connect(conn, sockindex);
+  switch(rv) {
+  case CURLE_OK:
+    break;
+  default:
+    return rv;
   }
 
-  if(model)
-    PR_Close(model);
-
-    /* cleanup on connection failure */
-    Curl_llist_destroy(connssl->obj_list, NULL);
-    connssl->obj_list = NULL;
-
-  if(ssl3 && tlsv1 && isTLSIntoleranceError(err)) {
-    /* schedule reconnect through Curl_retry_request() */
-    data->state.ssl_connect_retry = TRUE;
-    infof(data, "Error in TLS handshake, trying SSLv3...\n");
-    return CURLE_OK;
-  }
+  /* switch the SSL socket into non-blocking mode */
+  rv = nss_set_nonblock(connssl, data);
+  if(rv)
+    return rv;
 
-  return curlerr;
+  return CURLE_OK;
 }
-
+ 
 static ssize_t nss_send(struct connectdata *conn,  /* connection data */
                         int sockindex,             /* socketindex */
                         const void *mem,           /* send this data */
-- 
1.7.1


From f373ea815c8130f9f3c0b412c1fc092bb242699b Mon Sep 17 00:00:00 2001
From: Kamil Dudka <kdudka@redhat.com>
Date: Thu, 17 Apr 2014 13:27:39 +0200
Subject: [PATCH 2/3] nss: implement non-blocking SSL handshake

[upstream commit 8868a226cdad66a9a07d6e3f168884817592a1df]

Signed-off-by: Kamil Dudka <kdudka@redhat.com>
---
 lib/nss.c     |   57 ++++++++++++++++++++++++++++++++++++++++++++++++---------
 lib/nssg.h    |    1 +
 lib/urldata.h |    1 +
 3 files changed, 50 insertions(+), 9 deletions(-)

diff --git a/lib/nss.c b/lib/nss.c
index b21daf0..589e5b8 100644
--- a/lib/nss.c
+++ b/lib/nss.c
@@ -1468,7 +1468,10 @@ static CURLcode nss_do_connect(struct connectdata *conn, int sockindex)
   /* Force the handshake now */
   timeout = PR_MillisecondsToInterval((PRUint32) time_left);
   if(SSL_ForceHandshakeWithTimeout(connssl->handle, timeout) != SECSuccess) {
-    if(conn->data->set.ssl.certverifyresult == SSL_ERROR_BAD_CERT_DOMAIN)
+    if(PR_GetError() == PR_WOULD_BLOCK_ERROR)
+      /* TODO: propagate the blocking direction from the NSPR layer */
+      return CURLE_AGAIN;
+    else if(conn->data->set.ssl.certverifyresult == SSL_ERROR_BAD_CERT_DOMAIN)
       curlerr = CURLE_PEER_FAILED_VERIFICATION;
     else if(conn->data->set.ssl.certverifyresult!=0)
       curlerr = CURLE_SSL_CACERT;
@@ -1506,32 +1509,68 @@ error:
   return nss_fail_connect(connssl, data, curlerr);
 }
 
-CURLcode Curl_nss_connect(struct connectdata *conn, int sockindex)
+static CURLcode nss_connect_common(struct connectdata *conn, int sockindex,
+                                   bool *done)
 {
   struct ssl_connect_data *connssl = &conn->ssl[sockindex];
   struct SessionHandle *data = conn->data;
+  const bool blocking = (done == NULL);
   CURLcode rv;
 
-  rv = nss_setup_connect(conn, sockindex);
-  if(rv)
-    return rv;
+  if(connssl->connecting_state == ssl_connect_1) {
+    rv = nss_setup_connect(conn, sockindex);
+    if(rv)
+      /* we do not expect CURLE_AGAIN from nss_setup_connect() */
+      return rv;
+
+    if(!blocking) {
+      /* in non-blocking mode, set NSS non-blocking mode before handshake */
+      rv = nss_set_nonblock(connssl, data);
+      if(rv)
+        return rv;
+    }
+
+    connssl->connecting_state = ssl_connect_2;
+  }
 
   rv = nss_do_connect(conn, sockindex);
   switch(rv) {
   case CURLE_OK:
     break;
+  case CURLE_AGAIN:
+    if(!blocking)
+      /* CURLE_AGAIN in non-blocking mode is not an error */
+      return CURLE_OK;
+    /* fall through */
   default:
     return rv;
   }
 
-  /* switch the SSL socket into non-blocking mode */
-  rv = nss_set_nonblock(connssl, data);
-  if(rv)
-    return rv;
+  if(blocking) {
+    /* in blocking mode, set NSS non-blocking mode _after_ SSL handshake */
+    rv = nss_set_nonblock(connssl, data);
+    if(rv)
+      return rv;
+  }
+  else
+    /* signal completed SSL handshake */
+    *done = TRUE;
 
+  connssl->connecting_state = ssl_connect_done;
   return CURLE_OK;
 }
  
+CURLcode Curl_nss_connect(struct connectdata *conn, int sockindex)
+{
+  return nss_connect_common(conn, sockindex, /* blocking */ NULL);
+}
+
+CURLcode Curl_nss_connect_nonblocking(struct connectdata *conn,
+                                      int sockindex, bool *done)
+{
+  return nss_connect_common(conn, sockindex, done);
+}
+
 static ssize_t nss_send(struct connectdata *conn,  /* connection data */
                         int sockindex,             /* socketindex */
                         const void *mem,           /* send this data */
diff --git a/lib/nssg.h b/lib/nssg.h
index cd32706..e1ae464 100644
--- a/lib/nssg.h
+++ b/lib/nssg.h
@@ -68,6 +68,7 @@ void Curl_nss_md5sum(unsigned char *tmp, /* input */
 #define curlssl_init Curl_nss_init
 #define curlssl_cleanup Curl_nss_cleanup
 #define curlssl_connect Curl_nss_connect
+#define curlssl_connect_nonblocking Curl_nss_connect_nonblocking
 
 /* NSS has its own session ID cache */
 #define curlssl_session_free(x) Curl_nop_stmt
diff --git a/lib/urldata.h b/lib/urldata.h
index cbf4102..62413e6 100644
--- a/lib/urldata.h
+++ b/lib/urldata.h
@@ -323,6 +323,7 @@ struct ssl_connect_data {
   struct SessionHandle *data;
   struct curl_llist *obj_list;
   PK11GenericObject *obj_clicert;
+  ssl_connect_state connecting_state;
 #endif /* USE_NSS */
 #ifdef USE_QSOSSL
   SSLHandle *handle;
-- 
1.7.1


From 6ce73c703fb27b1214642a7635850151bd38a928 Mon Sep 17 00:00:00 2001
From: Kamil Dudka <kdudka@redhat.com>
Date: Wed, 23 Apr 2014 15:37:26 +0200
Subject: [PATCH 3/3] nss: propagate blocking direction from NSPR I/O

... during the non-blocking SSL handshake

[upstream commit 9c941e92c4bd3d2a5dbe243f7517b6a6029afc6e]

Signed-off-by: Kamil Dudka <kdudka@redhat.com>
---
 lib/http.c |    2 +-
 lib/nss.c  |  108 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 104 insertions(+), 6 deletions(-)

diff --git a/lib/http.c b/lib/http.c
index c78036b..d9b792e 100644
--- a/lib/http.c
+++ b/lib/http.c
@@ -1353,7 +1353,7 @@ static CURLcode https_connecting(struct connectdata *conn, bool *done)
 #endif
 
 #if defined(USE_SSLEAY) || defined(USE_GNUTLS) || defined(USE_SCHANNEL) || \
-    defined(USE_DARWINSSL)
+    defined(USE_DARWINSSL) || defined(USE_NSS)
 /* This function is for OpenSSL, GnuTLS, darwinssl, and schannel only.
    It should be made to query the generic SSL layer instead. */
 static int https_getsock(struct connectdata *conn,
diff --git a/lib/nss.c b/lib/nss.c
index 589e5b8..424c0b2 100644
--- a/lib/nss.c
+++ b/lib/nss.c
@@ -171,6 +171,10 @@ static const int enable_ciphers_by_default[] = {
 static const char* pem_library = "libnsspem.so";
 SECMODModule* mod = NULL;
 
+/* NSPR I/O layer we use to detect blocking direction during SSL handshake */
+static PRDescIdentity nspr_io_identity = PR_INVALID_IO_LAYER;
+static PRIOMethods nspr_io_methods;
+
 static const char* nss_error_to_name(PRErrorCode code)
 {
   const char *name = PR_ErrorToName(code);
@@ -852,6 +856,60 @@ isTLSIntoleranceError(PRInt32 err)
   }
 }
 
+/* update blocking direction in case of PR_WOULD_BLOCK_ERROR */
+static void nss_update_connecting_state(ssl_connect_state state, void *secret)
+{
+  struct ssl_connect_data *connssl = (struct ssl_connect_data *)secret;
+  if(PR_GetError() != PR_WOULD_BLOCK_ERROR)
+    /* an unrelated error is passing by */
+    return;
+
+  switch(connssl->connecting_state) {
+  case ssl_connect_2:
+  case ssl_connect_2_reading:
+  case ssl_connect_2_writing:
+    break;
+  default:
+    /* we are not called from an SSL handshake */
+    return;
+  }
+
+  /* update the state accordingly */
+  connssl->connecting_state = state;
+}
+
+/* recv() wrapper we use to detect blocking direction during SSL handshake */
+static PRInt32 nspr_io_recv(PRFileDesc *fd, void *buf, PRInt32 amount,
+                            PRIntn flags, PRIntervalTime timeout)
+{
+  const PRRecvFN recv_fn = fd->lower->methods->recv;
+  const PRInt32 rv = recv_fn(fd->lower, buf, amount, flags, timeout);
+  if(rv < 0)
+    /* check for PR_WOULD_BLOCK_ERROR and update blocking direction */
+    nss_update_connecting_state(ssl_connect_2_reading, fd->secret);
+  return rv;
+}
+
+/* send() wrapper we use to detect blocking direction during SSL handshake */
+static PRInt32 nspr_io_send(PRFileDesc *fd, const void *buf, PRInt32 amount,
+                            PRIntn flags, PRIntervalTime timeout)
+{
+  const PRSendFN send_fn = fd->lower->methods->send;
+  const PRInt32 rv = send_fn(fd->lower, buf, amount, flags, timeout);
+  if(rv < 0)
+    /* check for PR_WOULD_BLOCK_ERROR and update blocking direction */
+    nss_update_connecting_state(ssl_connect_2_writing, fd->secret);
+  return rv;
+}
+
+/* close() wrapper to avoid assertion failure due to fd->secret != NULL */
+static PRStatus nspr_io_close(PRFileDesc *fd)
+{
+  const PRCloseFN close_fn = PR_GetDefaultIOMethods()->close;
+  fd->secret = NULL;
+  return close_fn(fd);
+}
+
 static CURLcode nss_init_core(struct SessionHandle *data, const char *cert_dir)
 {
 #ifdef HAVE_NSS_INITCONTEXT
@@ -936,6 +994,21 @@ static CURLcode nss_init(struct SessionHandle *data)
     }
   }
 
+  if(nspr_io_identity == PR_INVALID_IO_LAYER) {
+    /* allocate an identity for our own NSPR I/O layer */
+    nspr_io_identity = PR_GetUniqueIdentity("libcurl");
+    if(nspr_io_identity == PR_INVALID_IO_LAYER)
+      return CURLE_OUT_OF_MEMORY;
+
+    /* the default methods just call down to the lower I/O layer */
+    memcpy(&nspr_io_methods, PR_GetDefaultIOMethods(), sizeof nspr_io_methods);
+
+    /* override certain methods in the table by our wrappers */
+    nspr_io_methods.recv  = nspr_io_recv;
+    nspr_io_methods.send  = nspr_io_send;
+    nspr_io_methods.close = nspr_io_close;
+  }
+
   rv = nss_init_core(data, cert_dir);
   if(rv)
     return rv;
@@ -1229,6 +1302,8 @@ static CURLcode nss_set_nonblock(struct ssl_connect_data *connssl,
 static CURLcode nss_setup_connect(struct connectdata *conn, int sockindex)
 {
   PRFileDesc *model = NULL;
+  PRFileDesc *nspr_io = NULL;
+  PRFileDesc *nspr_io_stub = NULL;
   PRBool ssl2 = PR_FALSE;
   PRBool ssl3 = PR_FALSE;
   PRBool tlsv1 = PR_FALSE;
@@ -1422,11 +1497,34 @@ static CURLcode nss_setup_connect(struct connectdata *conn, int sockindex)
     goto error;
   }
 
-  /* Import our model socket  onto the existing file descriptor */
-  connssl->handle = PR_ImportTCPSocket(sockfd);
-  connssl->handle = SSL_ImportFD(model, connssl->handle);
-  if(!connssl->handle)
+  /* wrap OS file descriptor by NSPR's file descriptor abstraction */
+  nspr_io = PR_ImportTCPSocket(sockfd);
+  if(!nspr_io)
+    goto error;
+
+  /* create our own NSPR I/O layer */
+  nspr_io_stub = PR_CreateIOLayerStub(nspr_io_identity, &nspr_io_methods);
+  if(!nspr_io_stub) {
+    PR_Close(nspr_io);
     goto error;
+  }
+
+  /* make the per-connection data accessible from NSPR I/O callbacks */
+  nspr_io_stub->secret = (void *)connssl;
+
+  /* push our new layer to the NSPR I/O stack */
+  if(PR_PushIOLayer(nspr_io, PR_TOP_IO_LAYER, nspr_io_stub) != PR_SUCCESS) {
+    PR_Close(nspr_io);
+    PR_Close(nspr_io_stub);
+    goto error;
+  }
+
+  /* import our model socket onto the current I/O stack */
+  connssl->handle = SSL_ImportFD(model, nspr_io);
+  if(!connssl->handle) {
+    PR_Close(nspr_io);
+    goto error;
+  }
 
   PR_Close(model); /* We don't need this any more */
   model = NULL;
@@ -1469,7 +1567,7 @@ static CURLcode nss_do_connect(struct connectdata *conn, int sockindex)
   timeout = PR_MillisecondsToInterval((PRUint32) time_left);
   if(SSL_ForceHandshakeWithTimeout(connssl->handle, timeout) != SECSuccess) {
     if(PR_GetError() == PR_WOULD_BLOCK_ERROR)
-      /* TODO: propagate the blocking direction from the NSPR layer */
+      /* blocking direction is updated by nss_update_connecting_state() */
       return CURLE_AGAIN;
     else if(conn->data->set.ssl.certverifyresult == SSL_ERROR_BAD_CERT_DOMAIN)
       curlerr = CURLE_PEER_FAILED_VERIFICATION;
-- 
1.7.1