Difference between revisions of "BIO"

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(Source/sink BIOs)
(Combining Filters and Source Sink BIOs)
 
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implementation of those bio are within bio/bss_xxx.c bss stading for Bio Source Sink
 
implementation of those bio are within bio/bss_xxx.c bss stading for Bio Source Sink
  
== Combining Filters and Source Sink BIOS ==
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== Combining Filters and Source Sink BIOs ==
  
* [[Manual:BIO_push(2)]]
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* [[Manual:BIO_push(3)]]
  
 
new_head = BIO_push(BIO * local_head, BIO * tail)  
 
new_head = BIO_push(BIO * local_head, BIO * tail)  
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will connect tail at end of local_head chain.
 
will connect tail at end of local_head chain.
  
WARNING BIO_push will never fail, but can create totaly invalid chains.
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WARNING BIO_push will never fail, but can create invalid chains.
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In standard usage end of a chain is a source sink, and all other elements are filters.
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* [[Manual:BIO_s_bio(3)]]
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two separated BIOs can then be connected with BIO_make_bio_pair() into a connected pair.

Latest revision as of 07:37, 1 November 2014

A BIO is an I/O stream abstraction; essentially OpenSSL's answer to the C library's FILE *. OpenSSL comes with a number of useful BIO types predefined, or you can create your own.

BIOs come in two flavors: source/sink, or filter. BIOs can be chained together. Each chain always has exactly one source/sink, but can have any number (zero or more) of filters.

Reading from a BIO can be done with Manual:BIO_read(3) and BIO_gets.

Writing to a BIO can be done with BIO_write, BIO_puts, BIO_printf, and BIO_vprintf.

Filter BIOs[edit]

Source/sink BIOs[edit]

implementation of those bio are within bio/bss_xxx.c bss stading for Bio Source Sink

Combining Filters and Source Sink BIOs[edit]

new_head = BIO_push(BIO * local_head, BIO * tail)

will connect tail at end of local_head chain.

WARNING BIO_push will never fail, but can create invalid chains.

In standard usage end of a chain is a source sink, and all other elements are filters.

two separated BIOs can then be connected with BIO_make_bio_pair() into a connected pair.