Botan::EC_AffinePoint Class Reference

#include <ec_apoint.h>

Public Member Functions
const std::shared_ptr< const EC_Group_Data > &	_group () const
const EC_AffinePoint_Data &	_inner () const
EC_AffinePoint	add (const EC_AffinePoint &q) const
	EC_AffinePoint (const EC_AffinePoint &other)
	EC_AffinePoint (const EC_Group &group, std::span< const uint8_t > bytes)
	EC_AffinePoint (EC_AffinePoint &&other) noexcept
size_t	field_element_bytes () const
bool	is_identity () const
	Return true if this point is the identity element.
EC_AffinePoint	mul (const EC_Scalar &scalar, RandomNumberGenerator &rng) const
	Multiply a point by a scalar returning a complete point.
EC_AffinePoint	mul (const EC_Scalar &scalar, RandomNumberGenerator &rng, std::vector< BigInt > &) const
secure_vector< uint8_t >	mul_x_only (const EC_Scalar &scalar, RandomNumberGenerator &rng) const
	Multiply a point by a scalar, returning the byte encoding of the x coordinate only.
secure_vector< uint8_t >	mul_x_only (const EC_Scalar &scalar, RandomNumberGenerator &rng, std::vector< BigInt > &) const
	Multiply a point by a scalar, returning the byte encoding of the x coordinate only.
EC_AffinePoint	negate () const
	Point negation.
bool	operator!= (const EC_AffinePoint &other) const
EC_AffinePoint &	operator= (const EC_AffinePoint &other)
EC_AffinePoint &	operator= (EC_AffinePoint &&other) noexcept
bool	operator== (const EC_AffinePoint &other) const
std::vector< uint8_t >	serialize (EC_Point_Format format) const
	Return an encoding depending on the requested format.
template<concepts::resizable_byte_buffer T = std::vector<uint8_t>>
T	serialize_compressed () const
void	serialize_compressed_to (std::span< uint8_t > bytes) const
template<concepts::resizable_byte_buffer T = std::vector<uint8_t>>
T	serialize_uncompressed () const
void	serialize_uncompressed_to (std::span< uint8_t > bytes) const
void	serialize_x_to (std::span< uint8_t > bytes) const
void	serialize_xy_to (std::span< uint8_t > bytes) const
void	serialize_y_to (std::span< uint8_t > bytes) const
template<concepts::resizable_byte_buffer T = secure_vector<uint8_t>>
T	x_bytes () const
template<concepts::resizable_byte_buffer T = secure_vector<uint8_t>>
T	xy_bytes () const
template<concepts::resizable_byte_buffer T = secure_vector<uint8_t>>
T	y_bytes () const
	~EC_AffinePoint ()

Static Public Member Functions
static EC_AffinePoint	_from_inner (std::unique_ptr< EC_AffinePoint_Data > inner)
static std::optional< EC_AffinePoint >	deserialize (const EC_Group &group, std::span< const uint8_t > bytes)
static std::optional< EC_AffinePoint >	from_bigint_xy (const EC_Group &group, const BigInt &x, const BigInt &y)
static EC_AffinePoint	g_mul (const EC_Scalar &scalar, RandomNumberGenerator &rng)
	Multiply by the group generator returning a complete point.
static EC_AffinePoint	g_mul (const EC_Scalar &scalar, RandomNumberGenerator &rng, std::vector< BigInt > &)
static EC_AffinePoint	generator (const EC_Group &group)
	Return the standard group generator.
static EC_AffinePoint	hash_to_curve_nu (const EC_Group &group, std::string_view hash_fn, std::span< const uint8_t > input, std::span< const uint8_t > domain_sep)
static EC_AffinePoint	hash_to_curve_nu (const EC_Group &group, std::string_view hash_fn, std::span< const uint8_t > input, std::string_view domain_sep)
static EC_AffinePoint	hash_to_curve_ro (const EC_Group &group, std::string_view hash_fn, std::span< const uint8_t > input, std::span< const uint8_t > domain_sep)
static EC_AffinePoint	hash_to_curve_ro (const EC_Group &group, std::string_view hash_fn, std::span< const uint8_t > input, std::string_view domain_sep)
static EC_AffinePoint	identity (const EC_Group &group)
	Return the identity element.
static std::optional< EC_AffinePoint >	mul_px_qy (const EC_AffinePoint &p, const EC_Scalar &x, const EC_AffinePoint &q, const EC_Scalar &y, RandomNumberGenerator &rng)

Friends
class	EC_Mul2Table

Detailed Description

Elliptic Curve Point in Affine Representation

Definition at line 36 of file ec_apoint.h.

Constructor & Destructor Documentation

EC_AffinePoint() [1/3]

Botan::EC_AffinePoint::EC_AffinePoint	(	const EC_Group &	group,
		std::span< const uint8_t >	bytes )

Point deserialization. Throws if wrong length or not a valid point

This accepts SEC1 compressed or uncompressed formats

Definition at line 36 of file ec_apoint.cpp.

                                                                                  {
   m_point = group._data()->point_deserialize(bytes);
   if(!m_point) {
      throw Decoding_Error("Failed to deserialize elliptic curve point");
   }
}

References Botan::EC_Group::_data().

Referenced by _from_inner(), add(), deserialize(), EC_AffinePoint(), EC_AffinePoint(), EC_Mul2Table, g_mul(), g_mul(), generator(), hash_to_curve_nu(), hash_to_curve_nu(), hash_to_curve_ro(), hash_to_curve_ro(), identity(), mul(), mul(), mul_px_qy(), negate(), operator!=(), operator=(), operator=(), and operator==().

EC_AffinePoint() [2/3]

Botan::EC_AffinePoint::EC_AffinePoint

(

const EC_AffinePoint &

other

)

Definition at line 20 of file ec_apoint.cpp.

: m_point(other.inner().clone()) {}

References EC_AffinePoint().

EC_AffinePoint() [3/3]

Botan::EC_AffinePoint::EC_AffinePoint ( EC_AffinePoint && other )

noexcept

Definition at line 22 of file ec_apoint.cpp.

: m_point(std::move(other.m_point)) {}

References EC_AffinePoint().

~EC_AffinePoint()

Botan::EC_AffinePoint::~EC_AffinePoint ( )

default

Member Function Documentation

_from_inner()

EC_AffinePoint Botan::EC_AffinePoint::_from_inner ( std::unique_ptr< EC_AffinePoint_Data > inner )

static

Definition at line 234 of file ec_apoint.cpp.

                                                                                   {
   return EC_AffinePoint(std::move(inner));
}

References EC_AffinePoint().

Referenced by Botan::EC_Group::Mul2Table::mul2_vartime().

_group()

const std::shared_ptr< const EC_Group_Data > & Botan::EC_AffinePoint::_group

(

)

const

Definition at line 238 of file ec_apoint.cpp.

                                                                       {
   return inner().group();
}

Referenced by operator==().

_inner()

const EC_AffinePoint_Data & Botan::EC_AffinePoint::_inner ( ) const

inline

Definition at line 263 of file ec_apoint.h.

{ return inner(); }

Referenced by add(), mul_px_qy(), and negate().

add()

EC_AffinePoint Botan::EC_AffinePoint::add

(

const EC_AffinePoint &

q

)

const

Point addition

Note that this is quite slow since it converts the resulting projective point immediately to affine coordinates, which requires a field inversion. This can be sufficient when implementing protocols that just need to perform a few additions.

In the future a cooresponding EC_ProjectivePoint type may be added which would avoid the expensive affine conversions

Definition at line 184 of file ec_apoint.cpp.

                                                                {
   auto pt = _inner().group()->affine_add(_inner(), q._inner());
   return EC_AffinePoint(std::move(pt));
}

References _inner(), EC_AffinePoint(), and Botan::EC_AffinePoint_Data::group().

deserialize()

std::optional< EC_AffinePoint > Botan::EC_AffinePoint::deserialize ( const EC_Group & group, std::span< const uint8_t > bytes )

static

Point deserialization. Returns nullopt if wrong length or not a valid point

This accepts SEC1 compressed or uncompressed formats

Definition at line 150 of file ec_apoint.cpp.

                                                                                                           {
   if(auto pt = group._data()->point_deserialize(bytes)) {
      return EC_AffinePoint(std::move(pt));
   } else {
      return {};
   }
}

References Botan::EC_Group::_data(), and EC_AffinePoint().

Referenced by from_bigint_xy().

field_element_bytes()

size_t Botan::EC_AffinePoint::field_element_bytes

(

)

const

Return the number of bytes of a field element

A point consists of two field elements, plus possibly a header

Definition at line 110 of file ec_apoint.cpp.

                                                 {
   return inner().field_element_bytes();
}

from_bigint_xy()

std::optional< EC_AffinePoint > Botan::EC_AffinePoint::from_bigint_xy ( const EC_Group & group, const BigInt & x, const BigInt & y )

static

Create a point from a pair (x,y) of integers

The integers must be within the field - in the range [0,p) and must satisfy the curve equation

Definition at line 93 of file ec_apoint.cpp.

                                                                                                                  {
   if(x.is_negative() || x >= group.get_p()) {
      return {};
   }
   if(y.is_negative() || y >= group.get_p()) {
      return {};
   }
 
   const size_t fe_bytes = group.get_p_bytes();
   std::vector<uint8_t> sec1(1 + 2 * fe_bytes);
   sec1[0] = 0x04;
   x.serialize_to(std::span{sec1}.subspan(1, fe_bytes));
   y.serialize_to(std::span{sec1}.last(fe_bytes));
 
   return EC_AffinePoint::deserialize(group, sec1);
}

References deserialize(), Botan::EC_Group::get_p(), Botan::EC_Group::get_p_bytes(), Botan::BigInt::is_negative(), and Botan::BigInt::serialize_to().

Referenced by generator().

g_mul() [1/2]

EC_AffinePoint Botan::EC_AffinePoint::g_mul ( const EC_Scalar & scalar, RandomNumberGenerator & rng )

static

Multiply by the group generator returning a complete point.

Definition at line 158 of file ec_apoint.cpp.

                                                                                        {
   auto pt = scalar._inner().group()->point_g_mul(scalar.inner(), rng);
   return EC_AffinePoint(std::move(pt));
}

References Botan::EC_Scalar::_inner(), EC_AffinePoint(), and Botan::EC_Scalar_Data::group().

Referenced by g_mul(), and Botan::EC_PrivateKey_Data::public_key().

g_mul() [2/2]

EC_AffinePoint Botan::EC_AffinePoint::g_mul ( const EC_Scalar & scalar, RandomNumberGenerator & rng, std::vector< BigInt > &  )

inlinestatic

Definition at line 245 of file ec_apoint.h.

                                                                                                             {
         return EC_AffinePoint::g_mul(scalar, rng);
      }

References EC_AffinePoint(), and g_mul().

generator()

EC_AffinePoint Botan::EC_AffinePoint::generator ( const EC_Group & group )

static

Return the standard group generator.

Definition at line 84 of file ec_apoint.cpp.

                                                              {
   // TODO it would be nice to improve this (pcurves supports returning generator directly)
   if(auto g = EC_AffinePoint::from_bigint_xy(group, group.get_g_x(), group.get_g_y())) {
      return *g;
   } else {
      throw Internal_Error("EC_AffinePoint::generator curve rejected generator");
   }
}

References EC_AffinePoint(), from_bigint_xy(), Botan::EC_Group::get_g_x(), and Botan::EC_Group::get_g_y().

Referenced by Botan::EC_Group::DER_encode().

hash_to_curve_nu() [1/2]

EC_AffinePoint Botan::EC_AffinePoint::hash_to_curve_nu ( const EC_Group & group, std::string_view hash_fn, std::span< const uint8_t > input, std::span< const uint8_t > domain_sep )

static

Hash to curve (RFC 9380), non uniform variant

Only supported for specific groups

Definition at line 133 of file ec_apoint.cpp.

                                                                                   {
   auto pt = group._data()->point_hash_to_curve_nu(hash_fn, input, domain_sep);
   return EC_AffinePoint(std::move(pt));
}

References Botan::EC_Group::_data(), and EC_AffinePoint().

Referenced by hash_to_curve_nu().

hash_to_curve_nu() [2/2]

EC_AffinePoint Botan::EC_AffinePoint::hash_to_curve_nu ( const EC_Group & group, std::string_view hash_fn, std::span< const uint8_t > input, std::string_view domain_sep )

static

Hash to curve (RFC 9380), non uniform variant

Only supported for specific groups

Definition at line 141 of file ec_apoint.cpp.

                                                                           {
   return EC_AffinePoint::hash_to_curve_nu(group, hash_fn, input, as_span_of_bytes(domain_sep));
}

References Botan::as_span_of_bytes(), EC_AffinePoint(), and hash_to_curve_nu().

hash_to_curve_ro() [1/2]

EC_AffinePoint Botan::EC_AffinePoint::hash_to_curve_ro ( const EC_Group & group, std::string_view hash_fn, std::span< const uint8_t > input, std::span< const uint8_t > domain_sep )

static

Hash to curve (RFC 9380), random oracle variant

Only supported for specific groups

Definition at line 118 of file ec_apoint.cpp.

                                                                                   {
   auto pt = group._data()->point_hash_to_curve_ro(hash_fn, input, domain_sep);
   return EC_AffinePoint(std::move(pt));
}

References Botan::EC_Group::_data(), and EC_AffinePoint().

Referenced by hash_to_curve_ro().

hash_to_curve_ro() [2/2]

EC_AffinePoint Botan::EC_AffinePoint::hash_to_curve_ro ( const EC_Group & group, std::string_view hash_fn, std::span< const uint8_t > input, std::string_view domain_sep )

static

Hash to curve (RFC 9380), random oracle variant

Only supported for specific groups

Definition at line 126 of file ec_apoint.cpp.

                                                                           {
   return EC_AffinePoint::hash_to_curve_ro(group, hash_fn, input, as_span_of_bytes(domain_sep));
}

References Botan::as_span_of_bytes(), EC_AffinePoint(), and hash_to_curve_ro().

identity()

EC_AffinePoint Botan::EC_AffinePoint::identity ( const EC_Group & group )

static

Return the identity element.

Definition at line 79 of file ec_apoint.cpp.

                                                             {
   const uint8_t id_encoding[1] = {0};
   return EC_AffinePoint(group, id_encoding);
}

References EC_AffinePoint().

is_identity()

bool Botan::EC_AffinePoint::is_identity

(

)

const

Return true if this point is the identity element.

Definition at line 114 of file ec_apoint.cpp.

                                       {
   return inner().is_identity();
}

Referenced by Botan::EC_PublicKey::check_key(), Botan::ECIES_KA_Operation::derive_secret(), operator==(), serialize_compressed_to(), serialize_uncompressed_to(), serialize_x_to(), serialize_xy_to(), and serialize_y_to().

mul() [1/2]

EC_AffinePoint Botan::EC_AffinePoint::mul	(	const EC_Scalar &	scalar,
		RandomNumberGenerator &	rng ) const

Multiply a point by a scalar returning a complete point.

Definition at line 163 of file ec_apoint.cpp.

                                                                                            {
   return EC_AffinePoint(inner().mul(scalar._inner(), rng));
}

References Botan::EC_Scalar::_inner(), EC_AffinePoint(), and mul().

Referenced by mul(), and mul().

mul() [2/2]

EC_AffinePoint Botan::EC_AffinePoint::mul ( const EC_Scalar & scalar, RandomNumberGenerator & rng, std::vector< BigInt > &  ) const

inline

Definition at line 250 of file ec_apoint.h.

                                                                                                          {
         return this->mul(scalar, rng);
      }

References EC_AffinePoint(), and mul().

mul_px_qy()

std::optional< EC_AffinePoint > Botan::EC_AffinePoint::mul_px_qy ( const EC_AffinePoint & p, const EC_Scalar & x, const EC_AffinePoint & q, const EC_Scalar & y, RandomNumberGenerator & rng )

static

Compute 2-ary multiscalar multiplication - p*x + q*y

This operation runs in constant time with respect to p, x, q, and y

Returns

p*x+q*y, or nullopt if the result was the point at infinity

Definition at line 171 of file ec_apoint.cpp.

                                                                                    {
   auto pt = p._inner().group()->mul_px_qy(p._inner(), x._inner(), q._inner(), y._inner(), rng);
   if(pt) {
      return EC_AffinePoint(std::move(pt));
   } else {
      return {};
   }
}

References _inner(), Botan::EC_Scalar::_inner(), EC_AffinePoint(), and Botan::EC_AffinePoint_Data::group().

mul_x_only() [1/2]

secure_vector< uint8_t > Botan::EC_AffinePoint::mul_x_only	(	const EC_Scalar &	scalar,
		RandomNumberGenerator &	rng ) const

Multiply a point by a scalar, returning the byte encoding of the x coordinate only.

Definition at line 167 of file ec_apoint.cpp.

                                                                                                           {
   return inner().mul_x_only(scalar._inner(), rng);
}

References Botan::EC_Scalar::_inner().

mul_x_only() [2/2]

secure_vector< uint8_t > Botan::EC_AffinePoint::mul_x_only ( const EC_Scalar & scalar, RandomNumberGenerator & rng, std::vector< BigInt > &  ) const

inline

Multiply a point by a scalar, returning the byte encoding of the x coordinate only.

Definition at line 255 of file ec_apoint.h.

                                                                    {
         return this->mul_x_only(scalar, rng);
      }

negate()

EC_AffinePoint Botan::EC_AffinePoint::negate

(

)

const

Point negation.

Definition at line 189 of file ec_apoint.cpp.

                                            {
   auto pt = this->_inner().group()->affine_neg(this->_inner());
   return EC_AffinePoint(std::move(pt));
}

References _inner(), EC_AffinePoint(), and Botan::EC_AffinePoint_Data::group().

operator!=()

bool Botan::EC_AffinePoint::operator!= ( const EC_AffinePoint & other ) const

inline

Definition at line 221 of file ec_apoint.h.

{ return !(*this == other); }

References EC_AffinePoint().

operator=() [1/2]

EC_AffinePoint & Botan::EC_AffinePoint::operator=

(

const EC_AffinePoint &

other

)

Definition at line 24 of file ec_apoint.cpp.

                                                                     {
   if(this != &other) {
      m_point = other.inner().clone();
   }
   return (*this);
}

References Botan::EC_AffinePoint_Data::clone(), and EC_AffinePoint().

operator=() [2/2]

EC_AffinePoint & Botan::EC_AffinePoint::operator= ( EC_AffinePoint && other )

noexcept

Definition at line 31 of file ec_apoint.cpp.

                                                                         {
   m_point.swap(other.m_point);
   return (*this);
}

References EC_AffinePoint().

operator==()

bool Botan::EC_AffinePoint::operator==

(

const EC_AffinePoint &

other

)

const

Definition at line 54 of file ec_apoint.cpp.

                                                                 {
   if(this == &other) {
      return true;
   }
 
   // We are relying on EC_Group to ensure there is just a single shared_ptr
   // for any set of group params
   if(this->_group() != other._group()) {
      return false;
   }
 
   auto a_is_id = this->is_identity();
   auto b_is_id = other.is_identity();
 
   if(a_is_id || b_is_id) {
      return (a_is_id == b_is_id);
   }
 
   auto a_xy = this->serialize_uncompressed();
   auto b_xy = other.serialize_uncompressed();
   BOTAN_ASSERT_NOMSG(a_xy.size() == b_xy.size());
 
   return CT::is_equal(a_xy.data(), b_xy.data(), a_xy.size()).as_bool();
}

References _group(), BOTAN_ASSERT_NOMSG, EC_AffinePoint(), Botan::CT::is_equal(), is_identity(), and serialize_uncompressed().

serialize()

std::vector< uint8_t > Botan::EC_AffinePoint::serialize

(

EC_Point_Format

format

)

const

Return an encoding depending on the requested format.

Definition at line 194 of file ec_apoint.cpp.

                                                                         {
   if(format == EC_Point_Format::Compressed) {
      return this->serialize_compressed();
   } else if(format == EC_Point_Format::Uncompressed) {
      return this->serialize_uncompressed();
   } else {
      // The deprecated "hybrid" point encoding
      // TODO(Botan4) Remove this
      auto enc = this->serialize_uncompressed();
      const bool y_is_odd = (enc[enc.size() - 1] & 0x01) == 0x01;
      enc.front() = y_is_odd ? 0x07 : 0x06;
      return enc;
   }
}

References Botan::Compressed, serialize_compressed(), serialize_uncompressed(), and Botan::Uncompressed.

Referenced by Botan::ECDH_PublicKey::public_value(), and Botan::EC_PublicKey::raw_public_key_bits().

serialize_compressed()

template<concepts::resizable_byte_buffer T = std::vector<uint8_t>>

T Botan::EC_AffinePoint::serialize_compressed ( ) const

inline

Return the bytes of the affine x and y coordinates in a container

This function will fail if this point is the identity element

Definition at line 213 of file ec_apoint.h.

                                     {
         T bytes(1 + this->field_element_bytes());
         this->serialize_compressed_to(bytes);
         return bytes;
      }

Referenced by Botan::ECDSA_PublicKey::recovery_param(), and serialize().

serialize_compressed_to()

void Botan::EC_AffinePoint::serialize_compressed_to

(

std::span< uint8_t >

bytes

)

const

Write the fixed length SEC1 compressed encoding

The output span must be exactly 1 + field_element_bytes long

This function will fail if this point is the identity element

Definition at line 224 of file ec_apoint.cpp.

                                                                         {
   BOTAN_STATE_CHECK(!this->is_identity());
   m_point->serialize_compressed_to(bytes);
}

References BOTAN_STATE_CHECK, and is_identity().

serialize_uncompressed()

template<concepts::resizable_byte_buffer T = std::vector<uint8_t>>

T Botan::EC_AffinePoint::serialize_uncompressed ( ) const

inline

Return the bytes of the affine x and y coordinates in a container

This function will fail if this point is the identity element

Definition at line 203 of file ec_apoint.h.

                                       {
         T bytes(1 + 2 * this->field_element_bytes());
         this->serialize_uncompressed_to(bytes);
         return bytes;
      }

Referenced by Botan::EC_Group::DER_encode(), operator==(), and serialize().

serialize_uncompressed_to()

void Botan::EC_AffinePoint::serialize_uncompressed_to

(

std::span< uint8_t >

bytes

)

const

Return the fixed length encoding of SEC1 uncompressed encoding

The output span must be exactly 1 + 2*field_element_bytes long

This function will fail if this point is the identity element

Definition at line 229 of file ec_apoint.cpp.

                                                                           {
   BOTAN_STATE_CHECK(!this->is_identity());
   m_point->serialize_uncompressed_to(bytes);
}

References BOTAN_STATE_CHECK, and is_identity().

serialize_x_to()

void Botan::EC_AffinePoint::serialize_x_to

(

std::span< uint8_t >

bytes

)

const

Write the fixed length encoding of affine x coordinate

The output span must be exactly field_element_bytes long

This function will fail if this point is the identity element

Definition at line 209 of file ec_apoint.cpp.

                                                                {
   BOTAN_STATE_CHECK(!this->is_identity());
   m_point->serialize_x_to(bytes);
}

References BOTAN_STATE_CHECK, and is_identity().

serialize_xy_to()

void Botan::EC_AffinePoint::serialize_xy_to

(

std::span< uint8_t >

bytes

)

const

Write the fixed length encoding of affine x and y coordinates

The output span must be exactly 2*field_element_bytes long

This function will fail if this point is the identity element

Definition at line 219 of file ec_apoint.cpp.

                                                                 {
   BOTAN_STATE_CHECK(!this->is_identity());
   m_point->serialize_xy_to(bytes);
}

References BOTAN_STATE_CHECK, and is_identity().

serialize_y_to()

void Botan::EC_AffinePoint::serialize_y_to

(

std::span< uint8_t >

bytes

)

const

Write the fixed length encoding of affine y coordinate

The output span must be exactly field_element_bytes long

This function will fail if this point is the identity element

Definition at line 214 of file ec_apoint.cpp.

                                                                {
   BOTAN_STATE_CHECK(!this->is_identity());
   m_point->serialize_y_to(bytes);
}

References BOTAN_STATE_CHECK, and is_identity().

x_bytes()

template<concepts::resizable_byte_buffer T = secure_vector<uint8_t>>

T Botan::EC_AffinePoint::x_bytes ( ) const

inline

Return the bytes of the affine x coordinate in a container

This function will fail if this point is the identity element

Definition at line 173 of file ec_apoint.h.

                        {
         T bytes(this->field_element_bytes());
         this->serialize_x_to(bytes);
         return bytes;
      }

xy_bytes()

template<concepts::resizable_byte_buffer T = secure_vector<uint8_t>>

T Botan::EC_AffinePoint::xy_bytes ( ) const

inline

Return the bytes of the affine x and y coordinates in a container

This function will fail if this point is the identity element

Definition at line 193 of file ec_apoint.h.

                         {
         T bytes(2 * this->field_element_bytes());
         this->serialize_xy_to(bytes);
         return bytes;
      }

Referenced by Botan::GOST_3410_PublicKey::public_key_bits(), and Botan::sm2_compute_za().

y_bytes()

template<concepts::resizable_byte_buffer T = secure_vector<uint8_t>>

T Botan::EC_AffinePoint::y_bytes ( ) const

inline

Return the bytes of the affine y coordinate in a container

This function will fail if this point is the identity element

Definition at line 183 of file ec_apoint.h.

                        {
         T bytes(this->field_element_bytes());
         this->serialize_y_to(bytes);
         return bytes;
      }

Friends And Related Symbol Documentation

EC_Mul2Table

friend class EC_Mul2Table

friend

Definition at line 270 of file ec_apoint.h.

References EC_AffinePoint(), and EC_Mul2Table.

Referenced by EC_Mul2Table.

---

The documentation for this class was generated from the following files:

• src/lib/pubkey/ec_group/ec_apoint.h
• src/lib/pubkey/ec_group/ec_apoint.cpp