Mini Shell

.\" Automatically generated by Pod::Man 4.14 (Pod::Simple 3.42)
.\"
.\" 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
..
.\" Set up some character translations and predefined strings.  \*(-- will
.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
.\" double quote, and \*(R" will give a right double quote.  \*(C+ will
.\" give a nicer C++.  Capital omega is used to do unbreakable dashes and
.\" therefore won't be available.  \*(C` and \*(C' expand to `' in nroff,
.\" nothing in troff, for use with C<>.
.tr \(*W-
.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
.ie n \{\
.    ds -- \(*W-
.    ds PI pi
.    if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
.    if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\"  diablo 12 pitch
.    ds L" ""
.    ds R" ""
.    ds C` ""
.    ds C' ""
'br\}
.el\{\
.    ds -- \|\(em\|
.    ds PI \(*p
.    ds L" ``
.    ds R" ''
.    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
.\"
.\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
.\" Fear.  Run.  Save yourself.  No user-serviceable parts.
.    \" fudge factors for nroff and troff
.if n \{\
.    ds #H 0
.    ds #V .8m
.    ds #F .3m
.    ds #[ \f1
.    ds #] \fP
.\}
.if t \{\
.    ds #H ((1u-(\\\\n(.fu%2u))*.13m)
.    ds #V .6m
.    ds #F 0
.    ds #[ \&
.    ds #] \&
.\}
.    \" simple accents for nroff and troff
.if n \{\
.    ds ' \&
.    ds ` \&
.    ds ^ \&
.    ds , \&
.    ds ~ ~
.    ds /
.\}
.if t \{\
.    ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
.    ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
.    ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
.    ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
.    ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
.    ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
.\}
.    \" troff and (daisy-wheel) nroff accents
.ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
.ds 8 \h'\*(#H'\(*b\h'-\*(#H'
.ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
.ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
.ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
.ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
.ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
.ds ae a\h'-(\w'a'u*4/10)'e
.ds Ae A\h'-(\w'A'u*4/10)'E
.    \" corrections for vroff
.if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
.if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
.    \" for low resolution devices (crt and lpr)
.if \n(.H>23 .if \n(.V>19 \
\{\
.    ds : e
.    ds 8 ss
.    ds o a
.    ds d- d\h'-1'\(ga
.    ds D- D\h'-1'\(hy
.    ds th \o'bp'
.    ds Th \o'LP'
.    ds ae ae
.    ds Ae AE
.\}
.rm #[ #] #H #V #F C
.\" ========================================================================
.\"
.IX Title "EVP_PKEY_CTX_NEW 3ossl"
.TH EVP_PKEY_CTX_NEW 3ossl "2024-09-03" "3.1.7+quic" "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"
EVP_PKEY_CTX_new, EVP_PKEY_CTX_new_id, EVP_PKEY_CTX_new_from_name,
EVP_PKEY_CTX_new_from_pkey, EVP_PKEY_CTX_dup, EVP_PKEY_CTX_free,
EVP_PKEY_CTX_is_a
\&\- public key algorithm context functions
.SH "SYNOPSIS"
.IX Header "SYNOPSIS"
.Vb 1
\& #include <openssl/evp.h>
\&
\& EVP_PKEY_CTX *EVP_PKEY_CTX_new(EVP_PKEY *pkey, ENGINE *e);
\& EVP_PKEY_CTX *EVP_PKEY_CTX_new_id(int id, ENGINE *e);
\& EVP_PKEY_CTX *EVP_PKEY_CTX_new_from_name(OSSL_LIB_CTX *libctx,
\&                                          const char *name,
\&                                          const char *propquery);
\& EVP_PKEY_CTX *EVP_PKEY_CTX_new_from_pkey(OSSL_LIB_CTX *libctx,
\&                                          EVP_PKEY *pkey,
\&                                          const char *propquery);
\& EVP_PKEY_CTX *EVP_PKEY_CTX_dup(const EVP_PKEY_CTX *ctx);
\& void EVP_PKEY_CTX_free(EVP_PKEY_CTX *ctx);
\& int EVP_PKEY_CTX_is_a(EVP_PKEY_CTX *ctx, const char *keytype);
.Ve
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
The \fBEVP_PKEY_CTX_new()\fR function allocates public key algorithm context using
the \fIpkey\fR key type and \s-1ENGINE\s0 \fIe\fR.
.PP
The \fBEVP_PKEY_CTX_new_id()\fR function allocates public key algorithm context
using the key type specified by \fIid\fR and \s-1ENGINE\s0 \fIe\fR.
.PP
The \fBEVP_PKEY_CTX_new_from_name()\fR function allocates a public key algorithm
context using the library context \fIlibctx\fR (see \s-1\fBOSSL_LIB_CTX\s0\fR\|(3)), the
key type specified by \fIname\fR and the property query \fIpropquery\fR.  None
of the arguments are duplicated, so they  must remain unchanged for the
lifetime of the returned \fB\s-1EVP_PKEY_CTX\s0\fR or of any of its duplicates.  Read
further about the possible names in \*(L"\s-1NOTES\*(R"\s0 below.
.PP
The \fBEVP_PKEY_CTX_new_from_pkey()\fR function allocates a public key algorithm
context using the library context \fIlibctx\fR (see \s-1\fBOSSL_LIB_CTX\s0\fR\|(3)) and the
algorithm specified by \fIpkey\fR and the property query \fIpropquery\fR. None of the
arguments are duplicated, so they must remain unchanged for the lifetime of the
returned \fB\s-1EVP_PKEY_CTX\s0\fR or any of its duplicates.
.PP
\&\fBEVP_PKEY_CTX_new_id()\fR and \fBEVP_PKEY_CTX_new_from_name()\fR are normally
used when no \fB\s-1EVP_PKEY\s0\fR structure is associated with the operations,
for example during parameter generation or key generation for some
algorithms.
.PP
\&\fBEVP_PKEY_CTX_dup()\fR duplicates the context \fIctx\fR. It is not supported for a
keygen operation.
.PP
\&\fBEVP_PKEY_CTX_free()\fR frees up the context \fIctx\fR.
If \fIctx\fR is \s-1NULL,\s0 nothing is done.
.PP
\&\fBEVP_PKEY_is_a()\fR checks if the key type associated with \fIctx\fR is \fIkeytype\fR.
.SH "NOTES"
.IX Header "NOTES"
.SS "On \fB\s-1EVP_PKEY_CTX\s0\fP"
.IX Subsection "On EVP_PKEY_CTX"
The \fB\s-1EVP_PKEY_CTX\s0\fR structure is an opaque public key algorithm context used
by the OpenSSL high-level public key \s-1API.\s0 Contexts \fB\s-1MUST NOT\s0\fR be shared between
threads: that is it is not permissible to use the same context simultaneously
in two threads.
.SS "On Key Types"
.IX Subsection "On Key Types"
We mention \*(L"key type\*(R" in this manual, which is the same
as \*(L"algorithm\*(R" in most cases, allowing either term to be used
interchangeably.  There are algorithms where the \fIkey type\fR and the
\&\fIalgorithm\fR of the operations that use the keys are not the same,
such as \s-1EC\s0 keys being used for \s-1ECDSA\s0 and \s-1ECDH\s0 operations.
.PP
Key types are given in two different manners:
.IP "Legacy \s-1NID\s0 or \s-1EVP_PKEY\s0 type" 4
.IX Item "Legacy NID or EVP_PKEY type"
This is the \fIid\fR used with \fBEVP_PKEY_CTX_new_id()\fR.
.Sp
These are \fB\s-1EVP_PKEY_RSA\s0\fR, \fB\s-1EVP_PKEY_RSA_PSS\s0\fR, \fB\s-1EVP_PKEY_DSA\s0\fR,
\&\fB\s-1EVP_PKEY_DH\s0\fR, \fB\s-1EVP_PKEY_EC\s0\fR, \fB\s-1EVP_PKEY_SM2\s0\fR, \fB\s-1EVP_PKEY_X25519\s0\fR,
\&\fB\s-1EVP_PKEY_X448\s0\fR, and are used by legacy methods.
.IP "Name strings" 4
.IX Item "Name strings"
This is the \fIname\fR used with \fBEVP_PKEY_CTX_new_from_name()\fR.
.Sp
These are names like \*(L"\s-1RSA\*(R", \*(L"DSA\*(R",\s0 and what's available depends on what
providers are currently accessible.
.Sp
The OpenSSL providers offer a set of key types available this way, please
see \s-1\fBOSSL_PROVIDER\-FIPS\s0\fR\|(7) and \fBOSSL_PROVIDER\-default\fR\|(7) and related
documentation for more information.
.SH "RETURN VALUES"
.IX Header "RETURN VALUES"
\&\fBEVP_PKEY_CTX_new()\fR, \fBEVP_PKEY_CTX_new_id()\fR and \fBEVP_PKEY_CTX_dup()\fR return either
the newly allocated \fB\s-1EVP_PKEY_CTX\s0\fR structure or \fB\s-1NULL\s0\fR if an error occurred.
.PP
\&\fBEVP_PKEY_CTX_free()\fR does not return a value.
.PP
\&\fBEVP_PKEY_CTX_is_a()\fR returns 1 for true and 0 for false.
.SH "SEE ALSO"
.IX Header "SEE ALSO"
\&\fBEVP_PKEY_new\fR\|(3)
.SH "HISTORY"
.IX Header "HISTORY"
The \fBEVP_PKEY_CTX_new()\fR, \fBEVP_PKEY_CTX_new_id()\fR, \fBEVP_PKEY_CTX_dup()\fR and
\&\fBEVP_PKEY_CTX_free()\fR functions were added in OpenSSL 1.0.0.
.PP
The \fBEVP_PKEY_CTX_new_from_name()\fR and \fBEVP_PKEY_CTX_new_from_pkey()\fR functions were
added in OpenSSL 3.0.
.SH "COPYRIGHT"
.IX Header "COPYRIGHT"
Copyright 2006\-2021 The OpenSSL Project Authors. All Rights Reserved.
.PP
Licensed under the Apache License 2.0 (the \*(L"License\*(R").  You may not use
this file except in compliance with the License.  You can obtain a copy
in the file \s-1LICENSE\s0 in the source distribution or at
<https://www.openssl.org/source/license.html>.