.\" Automatically generated by Pod::Man 4.10 (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_POINT_NEW 3"
.TH EC_POINT_NEW 3 "2019-02-26" "1.1.1b" "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_POINT_set_Jprojective_coordinates_GFp, EC_POINT_point2buf, EC_POINT_new, EC_POINT_free, EC_POINT_clear_free, EC_POINT_copy, EC_POINT_dup, EC_POINT_method_of, EC_POINT_set_to_infinity, EC_POINT_get_Jprojective_coordinates_GFp, EC_POINT_set_affine_coordinates, EC_POINT_get_affine_coordinates, EC_POINT_set_compressed_coordinates, EC_POINT_set_affine_coordinates_GFp, EC_POINT_get_affine_coordinates_GFp, EC_POINT_set_compressed_coordinates_GFp, EC_POINT_set_affine_coordinates_GF2m, EC_POINT_get_affine_coordinates_GF2m, EC_POINT_set_compressed_coordinates_GF2m, EC_POINT_point2oct, EC_POINT_oct2point, EC_POINT_point2bn, EC_POINT_bn2point, EC_POINT_point2hex, EC_POINT_hex2point \&\- Functions for creating, destroying and manipulating EC_POINT objects
.SH "SYNOPSIS"
.IX Header "SYNOPSIS"
.Vb 1
\& #include <openssl/ec.h>
\&
\& EC_POINT *EC_POINT_new(const EC_GROUP *group);
\& void EC_POINT_free(EC_POINT *point);
\& void EC_POINT_clear_free(EC_POINT *point);
\& int EC_POINT_copy(EC_POINT *dst, const EC_POINT *src);
\& EC_POINT *EC_POINT_dup(const EC_POINT *src, const EC_GROUP *group);
\& const EC_METHOD *EC_POINT_method_of(const EC_POINT *point);
\& int EC_POINT_set_to_infinity(const EC_GROUP *group, EC_POINT *point);
\& int EC_POINT_set_Jprojective_coordinates_GFp(const EC_GROUP *group,
\& EC_POINT *p,
\& const BIGNUM *x, const BIGNUM *y,
\& const BIGNUM *z, BN_CTX *ctx);
\& int EC_POINT_get_Jprojective_coordinates_GFp(const EC_GROUP *group,
\& const EC_POINT *p,
\& BIGNUM *x, BIGNUM *y, BIGNUM *z,
\& BN_CTX *ctx);
\& int EC_POINT_set_affine_coordinates(const EC_GROUP *group, EC_POINT *p,
\& const BIGNUM *x, const BIGNUM *y,
\& BN_CTX *ctx);
\& int EC_POINT_get_affine_coordinates(const EC_GROUP *group, const EC_POINT *p,
\& BIGNUM *x, BIGNUM *y, BN_CTX *ctx);
\& int EC_POINT_set_compressed_coordinates(const EC_GROUP *group, EC_POINT *p,
\& const BIGNUM *x, int y_bit,
\& BN_CTX *ctx);
\& int EC_POINT_set_affine_coordinates_GFp(const EC_GROUP *group, EC_POINT *p,
\& const BIGNUM *x, const BIGNUM *y,
\& BN_CTX *ctx);
\& int EC_POINT_get_affine_coordinates_GFp(const EC_GROUP *group,
\& const EC_POINT *p,
\& BIGNUM *x, BIGNUM *y, BN_CTX *ctx);
\& int EC_POINT_set_compressed_coordinates_GFp(const EC_GROUP *group,
\& EC_POINT *p,
\& const BIGNUM *x, int y_bit,
\& BN_CTX *ctx);
\& int EC_POINT_set_affine_coordinates_GF2m(const EC_GROUP *group, EC_POINT *p,
\& const BIGNUM *x, const BIGNUM *y,
\& BN_CTX *ctx);
\& int EC_POINT_get_affine_coordinates_GF2m(const EC_GROUP *group,
\& const EC_POINT *p,
\& BIGNUM *x, BIGNUM *y, BN_CTX *ctx);
\& int EC_POINT_set_compressed_coordinates_GF2m(const EC_GROUP *group,
\& EC_POINT *p,
\& const BIGNUM *x, int y_bit,
\& BN_CTX *ctx);
\& size_t EC_POINT_point2oct(const EC_GROUP *group, const EC_POINT *p,
\& point_conversion_form_t form,
\& unsigned char *buf, size_t len, BN_CTX *ctx);
\& size_t EC_POINT_point2buf(const EC_GROUP *group, const EC_POINT *point,
\& point_conversion_form_t form,
\& unsigned char **pbuf, BN_CTX *ctx);
\& int EC_POINT_oct2point(const EC_GROUP *group, EC_POINT *p,
\& const unsigned char *buf, size_t len, BN_CTX *ctx);
\& BIGNUM *EC_POINT_point2bn(const EC_GROUP *group, const EC_POINT *p,
\& point_conversion_form_t form, BIGNUM *bn,
\& BN_CTX *ctx);
\& EC_POINT *EC_POINT_bn2point(const EC_GROUP *group, const BIGNUM *bn,
\& EC_POINT *p, BN_CTX *ctx);
\& char *EC_POINT_point2hex(const EC_GROUP *group, const EC_POINT *p,
\& point_conversion_form_t form, BN_CTX *ctx);
\& EC_POINT *EC_POINT_hex2point(const EC_GROUP *group, const char *hex,
\& EC_POINT *p, BN_CTX *ctx);
.Ve
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
An \fB\s-1EC_POINT\s0\fR structure represents a point on a curve. A new point is
constructed by calling the function \fBEC_POINT_new()\fR and providing the
\&\fBgroup\fR object that the point relates to.
.PP
\&\fBEC_POINT_free()\fR frees the memory associated with the \fB\s-1EC_POINT\s0\fR.
if \fBpoint\fR is \s-1NULL\s0 nothing is done.
.PP
\&\fBEC_POINT_clear_free()\fR destroys any sensitive data held within the \s-1EC_POINT\s0 and
then frees its memory. If \fBpoint\fR is \s-1NULL\s0 nothing is done.
.PP
\&\fBEC_POINT_copy()\fR copies the point \fBsrc\fR into \fBdst\fR. Both \fBsrc\fR and \fBdst\fR
must use the same \fB\s-1EC_METHOD\s0\fR.
.PP
\&\fBEC_POINT_dup()\fR creates a new \fB\s-1EC_POINT\s0\fR object and copies the content from
\&\fBsrc\fR to the newly created \fB\s-1EC_POINT\s0\fR object.
.PP
\&\fBEC_POINT_method_of()\fR obtains the \fB\s-1EC_METHOD\s0\fR associated with \fBpoint\fR.
.PP
A valid point on a curve is the special point at infinity. A point is set to
be at infinity by calling \fBEC_POINT_set_to_infinity()\fR.
.PP
The affine co-ordinates for a point describe a point in terms of its x and y
position. The function \fBEC_POINT_set_affine_coordinates()\fR sets the \fBx\fR and \fBy\fR
co-ordinates for the point \fBp\fR defined over the curve given in \fBgroup\fR. The
function \fBEC_POINT_get_affine_coordinates()\fR sets \fBx\fR and \fBy\fR, either of which
may be \s-1NULL,\s0 to the corresponding coordinates of \fBp\fR.
.PP
The functions \fBEC_POINT_set_affine_coordinates_GFp()\fR and
\&\fBEC_POINT_set_affine_coordinates_GF2m()\fR are synonyms for
\&\fBEC_POINT_set_affine_coordinates()\fR. They are defined for backwards compatibility
only and should not be used.
.PP
The functions \fBEC_POINT_get_affine_coordinates_GFp()\fR and
\&\fBEC_POINT_get_affine_coordinates_GF2m()\fR are synonyms for
\&\fBEC_POINT_get_affine_coordinates()\fR. They are defined for backwards compatibility
only and should not be used.
.PP
As well as the affine co-ordinates, a point can alternatively be described in
terms of its Jacobian projective co-ordinates (for Fp curves only). Jacobian
projective co-ordinates are expressed as three values x, y and z. Working in
this co-ordinate system provides more efficient point multiplication
operations. A mapping exists between Jacobian projective co-ordinates and
affine co-ordinates. A Jacobian projective co-ordinate (x, y, z) can be written
as an affine co-ordinate as (x/(z^2), y/(z^3)). Conversion to Jacobian
projective from affine co-ordinates is simple. The co-ordinate (x, y) is mapped
to (x, y, 1). To set or get the projective co-ordinates use
\&\fBEC_POINT_set_Jprojective_coordinates_GFp()\fR and
\&\fBEC_POINT_get_Jprojective_coordinates_GFp()\fR respectively.
.PP
Points can also be described in terms of their compressed co-ordinates. For a
point (x, y), for any given value for x such that the point is on the curve
there will only ever be two possible values for y. Therefore a point can be set
using the \fBEC_POINT_set_compressed_coordinates()\fR function where \fBx\fR is the x
co-ordinate and \fBy_bit\fR is a value 0 or 1 to identify which of the two
possible values for y should be used.
.PP
The functions \fBEC_POINT_set_compressed_coordinates_GFp()\fR and
\&\fBEC_POINT_set_compressed_coordinates_GF2m()\fR are synonyms for
\&\fBEC_POINT_set_compressed_coordinates()\fR. They are defined for backwards
compatibility only and should not be used.
.PP
In addition \fB\s-1EC_POINT\s0\fR can be converted to and from various external
representations. The octet form is the binary encoding of the \fBECPoint\fR
structure (as defined in \s-1RFC5480\s0 and used in certificates and \s-1TLS\s0 records):
only the content octets are present, the \fB\s-1OCTET STRING\s0\fR tag and length are
not included. \fB\s-1BIGNUM\s0\fR form is the octet form interpreted as a big endian
integer converted to a \fB\s-1BIGNUM\s0\fR structure. Hexadecimal form is the octet
form converted to a \s-1NULL\s0 terminated character string where each character
is one of the printable values 0\-9 or A\-F (or a\-f).
.PP
The functions \fBEC_POINT_point2oct()\fR, \fBEC_POINT_oct2point()\fR, \fBEC_POINT_point2bn()\fR,
\&\fBEC_POINT_bn2point()\fR, \fBEC_POINT_point2hex()\fR and \fBEC_POINT_hex2point()\fR convert from
and to EC_POINTs for the formats: octet, \s-1BIGNUM\s0 and hexadecimal respectively.
.PP
The function \fBEC_POINT_point2oct()\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 still return the required buffer length.
.PP
The function \fBEC_POINT_point2buf()\fR allocates a buffer of suitable length and
writes an \s-1EC_POINT\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
The function \fBEC_POINT_point2hex()\fR will allocate sufficient memory to store the
hexadecimal string. It is the caller's responsibility to free this memory with
a subsequent call to \fBOPENSSL_free()\fR.
.SH "RETURN VALUES"
.IX Header "RETURN VALUES"
\&\fBEC_POINT_new()\fR and \fBEC_POINT_dup()\fR return the newly allocated \s-1EC_POINT\s0 or \s-1NULL\s0
on error.
.PP
The following functions return 1 on success or 0 on error: \fBEC_POINT_copy()\fR,
\&\fBEC_POINT_set_to_infinity()\fR, \fBEC_POINT_set_Jprojective_coordinates_GFp()\fR,
\&\fBEC_POINT_get_Jprojective_coordinates_GFp()\fR,
\&\fBEC_POINT_set_affine_coordinates_GFp()\fR, \fBEC_POINT_get_affine_coordinates_GFp()\fR,
\&\fBEC_POINT_set_compressed_coordinates_GFp()\fR,
\&\fBEC_POINT_set_affine_coordinates_GF2m()\fR, \fBEC_POINT_get_affine_coordinates_GF2m()\fR,
\&\fBEC_POINT_set_compressed_coordinates_GF2m()\fR and \fBEC_POINT_oct2point()\fR.
.PP
EC_POINT_method_of returns the \s-1EC_METHOD\s0 associated with the supplied \s-1EC_POINT.\s0
.PP
\&\fBEC_POINT_point2oct()\fR and \fBEC_POINT_point2buf()\fR return the length of the required
buffer or 0 on error.
.PP
\&\fBEC_POINT_point2bn()\fR returns the pointer to the \s-1BIGNUM\s0 supplied, or \s-1NULL\s0 on
error.
.PP
\&\fBEC_POINT_bn2point()\fR returns the pointer to the \s-1EC_POINT\s0 supplied, or \s-1NULL\s0 on
error.
.PP
\&\fBEC_POINT_point2hex()\fR returns a pointer to the hex string, or \s-1NULL\s0 on error.
.PP
\&\fBEC_POINT_hex2point()\fR returns the pointer to the \s-1EC_POINT\s0 supplied, or \s-1NULL\s0 on
error.
.SH "SEE ALSO"
.IX Header "SEE ALSO"
\&\fBcrypto\fR\|(7), \fBEC_GROUP_new\fR\|(3), \fBEC_GROUP_copy\fR\|(3),
\&\fBEC_POINT_add\fR\|(3), \fBEC_KEY_new\fR\|(3),
\&\fBEC_GFp_simple_method\fR\|(3), \fBd2i_ECPKParameters\fR\|(3)
.SH "COPYRIGHT"
.IX Header "COPYRIGHT"
Copyright 2013\-2018 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>.