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Diffstat (limited to 'secure/lib/libcrypto/man/man3/BIO_push.3')
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diff --git a/secure/lib/libcrypto/man/man3/BIO_push.3 b/secure/lib/libcrypto/man/man3/BIO_push.3 new file mode 100644 index 000000000000..5ea891c8ccfc --- /dev/null +++ b/secure/lib/libcrypto/man/man3/BIO_push.3 @@ -0,0 +1,155 @@ +.\" -*- mode: troff; coding: utf-8 -*- +.\" Automatically generated by Pod::Man 5.0102 (Pod::Simple 3.45) +.\" +.\" Standard preamble: +.\" ======================================================================== +.de Sp \" Vertical space (when we can't use .PP) +.if t .sp .5v +.if n .sp +.. +.de Vb \" Begin verbatim text +.ft CW +.nf +.ne \\$1 +.. +.de Ve \" End verbatim text +.ft R +.fi +.. +.\" \*(C` and \*(C' are quotes in nroff, nothing in troff, for use with C<>. +.ie n \{\ +. ds C` "" +. ds C' "" +'br\} +.el\{\ +. ds C` +. ds C' +'br\} +.\" +.\" Escape single quotes in literal strings from groff's Unicode transform. +.ie \n(.g .ds Aq \(aq +.el .ds Aq ' +.\" +.\" If the F register is >0, we'll generate index entries on stderr for +.\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index +.\" entries marked with X<> in POD. Of course, you'll have to process the +.\" output yourself in some meaningful fashion. +.\" +.\" Avoid warning from groff about undefined register 'F'. +.de IX +.. +.nr rF 0 +.if \n(.g .if rF .nr rF 1 +.if (\n(rF:(\n(.g==0)) \{\ +. if \nF \{\ +. de IX +. tm Index:\\$1\t\\n%\t"\\$2" +.. +. if !\nF==2 \{\ +. nr % 0 +. nr F 2 +. \} +. \} +.\} +.rr rF +.\" ======================================================================== +.\" +.IX Title "BIO_PUSH 3ossl" +.TH BIO_PUSH 3ossl 2025-09-30 3.5.4 OpenSSL +.\" For nroff, turn off justification. Always turn off hyphenation; it makes +.\" way too many mistakes in technical documents. +.if n .ad l +.nh +.SH NAME +BIO_push, BIO_pop, BIO_set_next \- add and remove BIOs from a chain +.SH SYNOPSIS +.IX Header "SYNOPSIS" +.Vb 1 +\& #include <openssl/bio.h> +\& +\& BIO *BIO_push(BIO *b, BIO *next); +\& BIO *BIO_pop(BIO *b); +\& void BIO_set_next(BIO *b, BIO *next); +.Ve +.SH DESCRIPTION +.IX Header "DESCRIPTION" +\&\fBBIO_push()\fR pushes \fIb\fR on \fInext\fR. +If \fIb\fR is NULL the function does nothing and returns \fInext\fR. +Otherwise it prepends \fIb\fR, which may be a single BIO or a chain of BIOs, +to \fInext\fR (unless \fInext\fR is NULL). +It then makes a control call on \fIb\fR and returns \fIb\fR. +.PP +\&\fBBIO_pop()\fR removes the BIO \fIb\fR from any chain is is part of. +If \fIb\fR is NULL the function does nothing and returns NULL. +Otherwise it makes a control call on \fIb\fR and +returns the next BIO in the chain, or NULL if there is no next BIO. +The removed BIO becomes a single BIO with no association with +the original chain, it can thus be freed or be made part of a different chain. +.PP +\&\fBBIO_set_next()\fR replaces the existing next BIO in a chain with the BIO pointed to +by \fInext\fR. The new chain may include some of the same BIOs from the old chain +or it may be completely different. +.SH NOTES +.IX Header "NOTES" +The names of these functions are perhaps a little misleading. \fBBIO_push()\fR +joins two BIO chains whereas \fBBIO_pop()\fR deletes a single BIO from a chain, +the deleted BIO does not need to be at the end of a chain. +.PP +The process of calling \fBBIO_push()\fR and \fBBIO_pop()\fR on a BIO may have additional +consequences (a control call is made to the affected BIOs). +Any effects will be noted in the descriptions of individual BIOs. +.SH "RETURN VALUES" +.IX Header "RETURN VALUES" +\&\fBBIO_push()\fR returns the head of the chain, +which usually is \fIb\fR, or \fInext\fR if \fIb\fR is NULL. +.PP +\&\fBBIO_pop()\fR returns the next BIO in the chain, +or NULL if there is no next BIO. +.SH EXAMPLES +.IX Header "EXAMPLES" +For these examples suppose \fImd1\fR and \fImd2\fR are digest BIOs, +\&\fIb64\fR is a base64 BIO and \fIf\fR is a file BIO. +.PP +If the call: +.PP +.Vb 1 +\& BIO_push(b64, f); +.Ve +.PP +is made then the new chain will be \fIb64\-f\fR. After making the calls +.PP +.Vb 2 +\& BIO_push(md2, b64); +\& BIO_push(md1, md2); +.Ve +.PP +the new chain is \fImd1\-md2\-b64\-f\fR. Data written to \fImd1\fR will be digested +by \fImd1\fR and \fImd2\fR, base64 encoded, and finally written to \fIf\fR. +.PP +It should be noted that reading causes data to pass in the reverse +direction, that is data is read from \fIf\fR, base64 decoded, +and digested by \fImd2\fR and then \fImd1\fR. +.PP +The call: +.PP +.Vb 1 +\& BIO_pop(md2); +.Ve +.PP +will return \fIb64\fR and the new chain will be \fImd1\-b64\-f\fR. +Data can be written to and read from \fImd1\fR as before, +except that \fImd2\fR will no more be applied. +.SH "SEE ALSO" +.IX Header "SEE ALSO" +\&\fBbio\fR\|(7) +.SH HISTORY +.IX Header "HISTORY" +The \fBBIO_set_next()\fR function was added in OpenSSL 1.1.0. +.SH COPYRIGHT +.IX Header "COPYRIGHT" +Copyright 2000\-2021 The OpenSSL Project Authors. All Rights Reserved. +.PP +Licensed under the Apache License 2.0 (the "License"). You may not use +this file except in compliance with the License. You can obtain a copy +in the file LICENSE in the source distribution or at +<https://www.openssl.org/source/license.html>. |