schannel SSL: changes in schannel_connect_step2

Process extra data buffer before returning from schannel_connect_step2.
Without this change I've seen WinCE hang when schannel_connect_step2
returns and calls Curl_socket_ready.

If the encrypted handshake does not fit in the intial buffer (seen with
large certificate chain), increasing the encrypted data buffer is necessary.

Fixed warning in curl_schannel.c line 1215.

lib/curl_schannel.c

@@ -290,6 +290,7 @@ schannel_connect_step2(struct connectdata *conn, int sockindex)
   SECURITY_STATUS sspi_status = SEC_E_OK;
   TCHAR *host_name;
   CURLcode code;
+  bool doread = TRUE;
 
   infof(data, "schannel: SSL/TLS connection with %s port %hu (step 2/3)\n",
         conn->host.name, conn->remote_port);
@@ -305,6 +306,22 @@ schannel_connect_step2(struct connectdata *conn, int sockindex)
     }
   }
 
+  /* if we need a bigger buffer to read a full message, increase buffer now */
+  if(connssl->encdata_offset == connssl->encdata_length) {
+    if(connssl->encdata_length >= CURL_SCHANNEL_BUFFER_INIT_SIZE * 16)
+      return CURLE_OUT_OF_MEMORY;
+    /* increase internal encrypted data buffer */
+    connssl->encdata_length *= 2;
+    connssl->encdata_buffer = realloc(connssl->encdata_buffer,
+                                      connssl->encdata_length);
+    if(connssl->encdata_buffer == NULL) {
+      failf(data, "schannel: unable to re-allocate memory");
+      return CURLE_OUT_OF_MEMORY;
+    }
+  }
+
+  for (;;) {
+    if(doread) {
       /* read encrypted handshake data from socket */
       code = Curl_read_plain(conn->sock[sockindex],
                 (char *) (connssl->encdata_buffer + connssl->encdata_offset),
@@ -325,6 +342,7 @@ schannel_connect_step2(struct connectdata *conn, int sockindex)
 
       /* increase encrypted data buffer offset */
       connssl->encdata_offset += nread;
+    }
 
     infof(data, "schannel: encrypted data buffer: offset %zu length %zu\n",
         connssl->encdata_offset, connssl->encdata_length);
@@ -346,7 +364,8 @@ schannel_connect_step2(struct connectdata *conn, int sockindex)
     }
 
     /* copy received handshake data into input buffer */
-  memcpy(inbuf[0].pvBuffer, connssl->encdata_buffer, connssl->encdata_offset);
+    memcpy(inbuf[0].pvBuffer, connssl->encdata_buffer,
+           connssl->encdata_offset);
 
 #ifdef UNICODE
     host_name = Curl_convert_UTF8_to_wchar(conn->host.name);
@@ -415,20 +434,34 @@ schannel_connect_step2(struct connectdata *conn, int sockindex)
     /* check if there was additional remaining encrypted data */
     if(inbuf[1].BufferType == SECBUFFER_EXTRA && inbuf[1].cbBuffer > 0) {
       infof(data, "schannel: encrypted data length: %lu\n", inbuf[1].cbBuffer);
-
+      /*
-    /* check if the remaining data is less than the total amount
+         There are two cases where we could be getting extra data here:
-     * and therefore begins after the already processed data
+         1) If we're renegotiating a connection and the handshake is already
+            complete (from the server perspective), it can encrypted app data
+            (not handshake data) in an extra buffer at this point.
+         2) (sspi_status == SEC_I_CONTINUE_NEEDED) We are negotiating a
+            connection and this extra data is part of the handshake.
+            We should process the data immediately; waiting for the socket to
+            be ready may fail since the server is done sending handshake data.
        */
+      /* check if the remaining data is less than the total amount
+         and therefore begins after the already processed data */
       if(connssl->encdata_offset > inbuf[1].cbBuffer) {
         memmove(connssl->encdata_buffer,
                 (connssl->encdata_buffer + connssl->encdata_offset) -
                   inbuf[1].cbBuffer, inbuf[1].cbBuffer);
         connssl->encdata_offset = inbuf[1].cbBuffer;
+        if(sspi_status == SEC_I_CONTINUE_NEEDED) {
+          doread = FALSE;
+          continue;
+        }
       }
     }
     else {
       connssl->encdata_offset = 0;
     }
+    break;
+  }
 
   /* check if the handshake needs to be continued */
   if(sspi_status == SEC_I_CONTINUE_NEEDED) {
@@ -1229,7 +1262,7 @@ static CURLcode verify_certificate(struct connectdata *conn, int sockindex)
         failf(data, "schannel: CertGetNameString() certificate hostname "
               "(%s) did not match connection (%s)",
               _cert_hostname, conn->host.name);
-        free(_cert_hostname);
+        free((void *)_cert_hostname);
       }
       free(hostname);
     }