22

✏️ Editing: EC_KEY_new.3

.\" Automatically generated by Pod::Man 4.11 (Pod::Simple 3.35)
.\"
.\" 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 "EC_KEY_NEW 3"
.TH EC_KEY_NEW 3 "2023-09-11" "1.1.1w" "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"
EC_KEY_get_method, EC_KEY_set_method, EC_KEY_new, EC_KEY_get_flags, EC_KEY_set_flags, EC_KEY_clear_flags, EC_KEY_new_by_curve_name, EC_KEY_free, EC_KEY_copy, EC_KEY_dup, EC_KEY_up_ref, EC_KEY_get0_engine, EC_KEY_get0_group, EC_KEY_set_group, EC_KEY_get0_private_key, EC_KEY_set_private_key, EC_KEY_get0_public_key, EC_KEY_set_public_key, EC_KEY_get_conv_form, EC_KEY_set_conv_form, EC_KEY_set_asn1_flag, EC_KEY_decoded_from_explicit_params, EC_KEY_precompute_mult, EC_KEY_generate_key, EC_KEY_check_key, EC_KEY_set_public_key_affine_coordinates, EC_KEY_oct2key, EC_KEY_key2buf, EC_KEY_oct2priv, EC_KEY_priv2oct, EC_KEY_priv2buf \- Functions for creating, destroying and manipulating EC_KEY objects
.SH "SYNOPSIS"
.IX Header "SYNOPSIS"
.Vb 1
\& #include <openssl/ec.h>
\&
\& EC_KEY *EC_KEY_new(void);
\& int EC_KEY_get_flags(const EC_KEY *key);
\& void EC_KEY_set_flags(EC_KEY *key, int flags);
\& void EC_KEY_clear_flags(EC_KEY *key, int flags);
\& EC_KEY *EC_KEY_new_by_curve_name(int nid);
\& void EC_KEY_free(EC_KEY *key);
\& EC_KEY *EC_KEY_copy(EC_KEY *dst, const EC_KEY *src);
\& EC_KEY *EC_KEY_dup(const EC_KEY *src);
\& int EC_KEY_up_ref(EC_KEY *key);
\& ENGINE *EC_KEY_get0_engine(const EC_KEY *eckey);
\& const EC_GROUP *EC_KEY_get0_group(const EC_KEY *key);
\& int EC_KEY_set_group(EC_KEY *key, const EC_GROUP *group);
\& const BIGNUM *EC_KEY_get0_private_key(const EC_KEY *key);
\& int EC_KEY_set_private_key(EC_KEY *key, const BIGNUM *priv_key);
\& const EC_POINT *EC_KEY_get0_public_key(const EC_KEY *key);
\& int EC_KEY_set_public_key(EC_KEY *key, const EC_POINT *pub);
\& point_conversion_form_t EC_KEY_get_conv_form(const EC_KEY *key);
\& void EC_KEY_set_conv_form(EC_KEY *eckey, point_conversion_form_t cform);
\& void EC_KEY_set_asn1_flag(EC_KEY *eckey, int asn1_flag);
\& int EC_KEY_decoded_from_explicit_params(const EC_KEY *key);
\& int EC_KEY_precompute_mult(EC_KEY *key, BN_CTX *ctx);
\& int EC_KEY_generate_key(EC_KEY *key);
\& int EC_KEY_check_key(const EC_KEY *key);
\& int EC_KEY_set_public_key_affine_coordinates(EC_KEY *key, BIGNUM *x, BIGNUM *y);
\& const EC_KEY_METHOD *EC_KEY_get_method(const EC_KEY *key);
\& int EC_KEY_set_method(EC_KEY *key, const EC_KEY_METHOD *meth);
\&
\& int EC_KEY_oct2key(EC_KEY *eckey, const unsigned char *buf, size_t len, BN_CTX *ctx);
\& size_t EC_KEY_key2buf(const EC_KEY *eckey, point_conversion_form_t form,
\&                       unsigned char **pbuf, BN_CTX *ctx);
\&
\& int EC_KEY_oct2priv(EC_KEY *eckey, const unsigned char *buf, size_t len);
\& size_t EC_KEY_priv2oct(const EC_KEY *eckey, unsigned char *buf, size_t len);
\&
\& size_t EC_KEY_priv2buf(const EC_KEY *eckey, unsigned char **pbuf);
.Ve
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
An \s-1EC_KEY\s0 represents a public key and, optionally, the associated private
key. A new \s-1EC_KEY\s0 with no associated curve can be constructed by calling
\&\fBEC_KEY_new()\fR. The reference count for the newly created \s-1EC_KEY\s0 is initially
set to 1. A curve can be associated with the \s-1EC_KEY\s0 by calling
\&\fBEC_KEY_set_group()\fR.
.PP
Alternatively a new \s-1EC_KEY\s0 can be constructed by calling
\&\fBEC_KEY_new_by_curve_name()\fR and supplying the nid of the associated curve. See
\&\fBEC_GROUP_new\fR\|(3) for a description of curve names. This function simply
wraps calls to \fBEC_KEY_new()\fR and \fBEC_GROUP_new_by_curve_name()\fR.
.PP
Calling \fBEC_KEY_free()\fR decrements the reference count for the \s-1EC_KEY\s0 object,
and if it has dropped to zero then frees the memory associated with it.  If
\&\fBkey\fR is \s-1NULL\s0 nothing is done.
.PP
\&\fBEC_KEY_copy()\fR copies the contents of the \s-1EC_KEY\s0 in \fBsrc\fR into \fBdest\fR.
.PP
\&\fBEC_KEY_dup()\fR creates a new \s-1EC_KEY\s0 object and copies \fBec_key\fR into it.
.PP
\&\fBEC_KEY_up_ref()\fR increments the reference count associated with the \s-1EC_KEY\s0
object.
.PP
\&\fBEC_KEY_get0_engine()\fR returns a handle to the \s-1ENGINE\s0 that has been set for
this \s-1EC_KEY\s0 object.
.PP
\&\fBEC_KEY_generate_key()\fR generates a new public and private key for the supplied
\&\fBeckey\fR object. \fBeckey\fR must have an \s-1EC_GROUP\s0 object associated with it
before calling this function. The private key is a random integer (0 < priv_key
< order, where \fIorder\fR is the order of the \s-1EC_GROUP\s0 object). The public key is
an \s-1EC_POINT\s0 on the curve calculated by multiplying the generator for the
curve by the private key.
.PP
\&\fBEC_KEY_check_key()\fR performs various sanity checks on the \s-1EC_KEY\s0 object to
confirm that it is valid.
.PP
\&\fBEC_KEY_set_public_key_affine_coordinates()\fR sets the public key for \fBkey\fR based
on its affine co-ordinates; i.e., it constructs an \s-1EC_POINT\s0 object based on
the supplied \fBx\fR and \fBy\fR values and sets the public key to be this
\&\s-1EC_POINT.\s0 It also performs certain sanity checks on the key to confirm
that it is valid.
.PP
The functions \fBEC_KEY_get0_group()\fR, \fBEC_KEY_set_group()\fR,
\&\fBEC_KEY_get0_private_key()\fR, \fBEC_KEY_set_private_key()\fR, \fBEC_KEY_get0_public_key()\fR,
and \fBEC_KEY_set_public_key()\fR get and set the \s-1EC_GROUP\s0 object, the private key,
and the \s-1EC_POINT\s0 public key for the \fBkey\fR respectively. The function
\&\fBEC_KEY_set_private_key()\fR accepts \s-1NULL\s0 as the priv_key argument to securely clear
the private key component from the \s-1EC_KEY.\s0
.PP
The functions \fBEC_KEY_get_conv_form()\fR and \fBEC_KEY_set_conv_form()\fR get and set the
point_conversion_form for the \fBkey\fR. For a description of
point_conversion_forms please see \fBEC_POINT_new\fR\|(3).
.PP
\&\fBEC_KEY_set_flags()\fR sets the flags in the \fBflags\fR parameter on the \s-1EC_KEY\s0
object. Any flags that are already set are left set. The flags currently
defined are \s-1EC_FLAG_NON_FIPS_ALLOW\s0 and \s-1EC_FLAG_FIPS_CHECKED.\s0 In
addition there is the flag \s-1EC_FLAG_COFACTOR_ECDH\s0 which is specific to \s-1ECDH.\s0
\&\fBEC_KEY_get_flags()\fR returns the current flags that are set for this \s-1EC_KEY.\s0
\&\fBEC_KEY_clear_flags()\fR clears the flags indicated by the \fBflags\fR parameter; all
other flags are left in their existing state.
.PP
\&\fBEC_KEY_set_asn1_flag()\fR sets the asn1_flag on the underlying \s-1EC_GROUP\s0 object
(if set). Refer to \fBEC_GROUP_copy\fR\|(3) for further information on the
asn1_flag.
.PP
\&\fBEC_KEY_decoded_from_explicit_params()\fR returns 1 if the group of the \fIkey\fR was
decoded from data with explicitly encoded group parameters, \-1 if the \fIkey\fR
is \s-1NULL\s0 or the group parameters are missing, and 0 otherwise.
.PP
\&\fBEC_KEY_precompute_mult()\fR stores multiples of the underlying \s-1EC_GROUP\s0 generator
for faster point multiplication. See also \fBEC_POINT_add\fR\|(3).
.PP
\&\fBEC_KEY_oct2key()\fR and \fBEC_KEY_key2buf()\fR are identical to the functions
\&\fBEC_POINT_oct2point()\fR and \fBEC_POINT_point2buf()\fR except they use the public key
\&\s-1EC_POINT\s0 in \fBeckey\fR.
.PP
\&\fBEC_KEY_oct2priv()\fR and \fBEC_KEY_priv2oct()\fR convert between the private key
component of \fBeckey\fR and octet form. The octet form consists of the content
octets of the \fBprivateKey\fR \s-1OCTET STRING\s0 in an \fBECPrivateKey\fR \s-1ASN.1\s0 structure.
.PP
The function \fBEC_KEY_priv2oct()\fR must be supplied with a buffer long enough to
store the octet form. The return value provides the number of octets stored.
Calling the function with a \s-1NULL\s0 buffer will not perform the conversion but
will just return the required buffer length.
.PP
The function \fBEC_KEY_priv2buf()\fR allocates a buffer of suitable length and writes
an \s-1EC_KEY\s0 to it in octet format. The allocated buffer is written to \fB*pbuf\fR
and its length is returned. The caller must free up the allocated buffer with a
call to \fBOPENSSL_free()\fR. Since the allocated buffer value is written to \fB*pbuf\fR
the \fBpbuf\fR parameter \fB\s-1MUST NOT\s0\fR be \fB\s-1NULL\s0\fR.
.PP
\&\fBEC_KEY_priv2buf()\fR converts an \s-1EC_KEY\s0 private key into an allocated buffer.
.SH "RETURN VALUES"
.IX Header "RETURN VALUES"
\&\fBEC_KEY_new()\fR, \fBEC_KEY_new_by_curve_name()\fR and \fBEC_KEY_dup()\fR return a pointer to
the newly created \s-1EC_KEY\s0 object, or \s-1NULL\s0 on error.
.PP
\&\fBEC_KEY_get_flags()\fR returns the flags associated with the \s-1EC_KEY\s0 object as an
integer.
.PP
\&\fBEC_KEY_copy()\fR returns a pointer to the destination key, or \s-1NULL\s0 on error.
.PP
\&\fBEC_KEY_get0_engine()\fR returns a pointer to an \s-1ENGINE,\s0 or \s-1NULL\s0 if it wasn't set.
.PP
\&\fBEC_KEY_up_ref()\fR, \fBEC_KEY_set_group()\fR, \fBEC_KEY_set_public_key()\fR,
\&\fBEC_KEY_precompute_mult()\fR, \fBEC_KEY_generate_key()\fR, \fBEC_KEY_check_key()\fR,
\&\fBEC_KEY_set_public_key_affine_coordinates()\fR, \fBEC_KEY_oct2key()\fR and
\&\fBEC_KEY_oct2priv()\fR return 1 on success or 0 on error.
.PP
\&\fBEC_KEY_set_private_key()\fR returns 1 on success or 0 on error except when the
priv_key argument is \s-1NULL,\s0 in that case it returns 0, for legacy compatibility,
and should not be treated as an error.
.PP
\&\fBEC_KEY_get0_group()\fR returns the \s-1EC_GROUP\s0 associated with the \s-1EC_KEY.\s0
.PP
\&\fBEC_KEY_get0_private_key()\fR returns the private key associated with the \s-1EC_KEY.\s0
.PP
\&\fBEC_KEY_get_conv_form()\fR return the point_conversion_form for the \s-1EC_KEY.\s0
.PP
\&\fBEC_KEY_key2buf()\fR, \fBEC_KEY_priv2oct()\fR and \fBEC_KEY_priv2buf()\fR return the length
of the buffer or 0 on error.
.SH "SEE ALSO"
.IX Header "SEE ALSO"
\&\fBcrypto\fR\|(7), \fBEC_GROUP_new\fR\|(3),
\&\fBEC_GROUP_copy\fR\|(3), \fBEC_POINT_new\fR\|(3),
\&\fBEC_POINT_add\fR\|(3),
\&\fBEC_GFp_simple_method\fR\|(3),
\&\fBd2i_ECPKParameters\fR\|(3)
.SH "COPYRIGHT"
.IX Header "COPYRIGHT"
Copyright 2013\-2022 The OpenSSL Project Authors. All Rights Reserved.
.PP
Licensed under the OpenSSL license (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>.

MR SKB