bio(3) OpenSSL bio(3) NAME bio - I/O abstraction SYNOPSIS #include <openssl/bio.h> TBA DESCRIPTION A BIO is an I/O abstraction, it hides many of the underlying I/O details from an application. If an application uses a BIO for its I/O it can transparently handle SSL connections, unencrypted network con- nections and file(1,n) I/O. There are two type of BIO, a source/sink BIO and a filter(1,3x,3x curs_util) BIO. As its name implies a source/sink BIO is a source and/or sink of data, examples include a socket(2,7,n) BIO and a file(1,n) BIO. A filter(1,3x,3x curs_util) BIO takes data from one BIO and passes it through to another, or the application. The data may be left unmodified (for example a mes- sage digest BIO) or translated (for example an encryption BIO). The effect of a filter(1,3x,3x curs_util) BIO may change according to the I/O operation it is performing: for example an encryption BIO will encrypt data if(3,n) it is being written to and decrypt data if(3,n) it is being read(2,n,1 builtins) from. BIOs can be joined together to form a chain (a single BIO is a chain with one component). A chain normally consist of one source/sink BIO and one or more filter(1,3x,3x curs_util) BIOs. Data read(2,n,1 builtins) from or written to the first BIO then traverses the chain to the end (normally a source/sink BIO). SEE ALSO BIO_ctrl(3), BIO_f_base64(3), BIO_f_buffer(3), BIO_f_cipher(3), BIO_f_md(3), BIO_f_null(3), BIO_f_ssl(3), BIO_find_type(3), BIO_new(3), BIO_new_bio_pair(3), BIO_push(3), BIO_read(3), BIO_s_accept(3), BIO_s_bio(3), BIO_s_connect(3), BIO_s_fd(3), BIO_s_file(3), BIO_s_mem(3), BIO_s_null(3), BIO_s_socket(3), BIO_set_callback(3), BIO_should_retry(3) 0.9.7d 2001-04-12 bio(3)