SSL_rstate_string() returns a 2 letter string indicating the current
read state of the SSL object ssl.
SSL_rstate_string_long() returns a string indicating the current read
state of the SSL object ssl.
NOTES
When performing a read operation, the SSL/TLS engine must parse the
record, consisting of header and body. When working in a blocking
environment, SSL_rstate_string[_long]() should always return
"RD"/"read done".
This function should only seldom be needed in applications.
RETURN VALUES
SSL_rstate_string() and SSL_rstate_string_long() can return the
following values:
"RH"/"read header"
The header of the record is being evaluated.
"RB"/"read body"
The body of the record is being evaluated.
"RD"/"read done"
The record has been completely processed.
"unknown"/"unknown"
The read state is unknown. This should never happen.