SSL_pending - obtain number of readable bytes buffered in an SSL object
int SSL_pending(SSL *ssl);
SSL_pending() returns the number of bytes which are available
ssl for immediate read.
Data are received in blocks from the peer. Therefore data can be buffered inside ssl and are ready for immediate retrieval with SSL_read(3).
The number of bytes pending is returned.
SSL_pending() takes into account only bytes from the TLS/SSL
record that is currently being processed (if any). If the SSL object's
read_ahead flag is set, additional protocol bytes may have been read containing more
TLS/SSL records; these are ignored by
Up to OpenSSL 0.9.6,
SSL_pending() does not check if the
record type of pending data is application data.