lcx_ecfp.h

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Key pair generation based on elliptic curves. More...

Data Structures
struct	cx_ecfp_public_key_s
	Elliptic Curve public key. More...
struct	cx_ecfp_private_key_s
	Elliptic Curve private key. More...
struct	cx_ecfp_256_public_key_s
	Up to 256-bit Elliptic Curve public key. More...
struct	cx_ecfp_256_private_key_s
	Up to 256-bit Elliptic Curve private key. More...
struct	cx_ecfp_256_extended_private_key_s
	Up to 256-bit Elliptic Curve extended private key. More...
struct	cx_ecfp_384_public_key_s
	Up to 384-bit Elliptic Curve public key. More...
struct	cx_ecfp_384_private_key_s
	Up to 384-bit Elliptic Curve private key. More...
struct	cx_ecfp_512_public_key_s
	Up to 512-bit Elliptic Curve public key. More...
struct	cx_ecfp_512_private_key_s
	Up to 512-bit Elliptic Curve private key. More...
struct	cx_ecfp_512_extented_private_key_s
	Up to 512-bit Elliptic Curve extended private key. More...
struct	cx_ecfp_640_public_key_s
	Up to 640-bit Elliptic Curve public key. More...
struct	cx_ecfp_640_private_key_s
	Up to 640-bit Elliptic Curve private key. More...

Typedefs
typedef struct cx_ecfp_256_public_key_s	cx_ecfp_256_public_key_t
	Convenience type. More...
typedef struct cx_ecfp_256_private_key_s	cx_ecfp_256_private_key_t
	temporary def type. More...
typedef struct cx_ecfp_256_extended_private_key_s	cx_ecfp_256_extended_private_key_t
	Convenience type. More...
typedef struct cx_ecfp_256_public_key_s	cx_ecfp_public_key_t
typedef struct cx_ecfp_256_private_key_s	cx_ecfp_private_key_t
typedef struct cx_ecfp_384_private_key_s	cx_ecfp_384_private_key_t
	Convenience type. More...
typedef struct cx_ecfp_384_public_key_s	cx_ecfp_384_public_key_t
	Convenience type. More...
typedef struct cx_ecfp_512_public_key_s	cx_ecfp_512_public_key_t
	Convenience type. More...
typedef struct cx_ecfp_512_private_key_s	cx_ecfp_512_private_key_t
	Convenience type. More...
typedef struct cx_ecfp_512_extented_private_key_s	cx_ecfp_512_extented_private_key_t
	Convenience type. More...
typedef struct cx_ecfp_640_public_key_s	cx_ecfp_640_public_key_t
	Convenience type. More...
typedef struct cx_ecfp_640_private_key_s	cx_ecfp_640_private_key_t
	Convenience type. More...

Functions
cx_err_t	cx_ecfp_add_point_no_throw (cx_curve_t curve, uint8_t *R, const uint8_t *P, const uint8_t *Q)
	Adds two points of an elliptic curve. More...
static int	cx_ecfp_add_point (cx_curve_t curve, unsigned char *R, const unsigned char *P, const unsigned char *Q, unsigned int X_len)
	Adds two points of an elliptic curve. More...
cx_err_t	cx_ecfp_scalar_mult_no_throw (cx_curve_t curve, uint8_t *P, const uint8_t *k, size_t k_len)
	Performs a scalar multiplication over an elliptic curve. More...
static int	cx_ecfp_scalar_mult (cx_curve_t curve, unsigned char *P, unsigned int P_len, const unsigned char *k, unsigned int k_len)
	Performs a scalar multiplication over an elliptic curve. More...
cx_err_t	cx_ecfp_init_public_key_no_throw (cx_curve_t curve, const uint8_t *rawkey, size_t key_len, cx_ecfp_public_key_t *key)
	Initializes a public key. More...
static int	cx_ecfp_init_public_key (cx_curve_t curve, const unsigned char *rawkey, unsigned int key_len, cx_ecfp_public_key_t *key)
	Initializes a public key. More...
cx_err_t	cx_ecfp_init_private_key_no_throw (cx_curve_t curve, const uint8_t *rawkey, size_t key_len, cx_ecfp_private_key_t *pvkey)
	Initializes a private key. More...
static int	cx_ecfp_init_private_key (cx_curve_t curve, const unsigned char *rawkey, unsigned int key_len, cx_ecfp_private_key_t *pvkey)
	Initializes a private key. More...
cx_err_t	cx_ecfp_generate_pair_no_throw (cx_curve_t curve, cx_ecfp_public_key_t *pubkey, cx_ecfp_private_key_t *privkey, bool keepprivate)
	Generates a key pair with SHA-512 hash function. More...
static int	cx_ecfp_generate_pair (cx_curve_t curve, cx_ecfp_public_key_t *pubkey, cx_ecfp_private_key_t *privkey, int keepprivate)
	Generates a key pair with SHA-512 hash function. More...
cx_err_t	cx_ecfp_generate_pair2_no_throw (cx_curve_t curve, cx_ecfp_public_key_t *pubkey, cx_ecfp_private_key_t *privkey, bool keepprivate, cx_md_t hashID)
	Generates a key pair. More...
static int	cx_ecfp_generate_pair2 (cx_curve_t curve, cx_ecfp_public_key_t *pubkey, cx_ecfp_private_key_t *privkey, int keepprivate, cx_md_t hashID)
	Generates a key pair. More...
cx_err_t	cx_eddsa_get_public_key_no_throw (const cx_ecfp_private_key_t *pvkey, cx_md_t hashID, cx_ecfp_public_key_t *pukey, uint8_t *a, size_t a_len, uint8_t *h, size_t h_len)
	Retrieves an EDDSA public key. More...
static void	cx_eddsa_get_public_key (const cx_ecfp_private_key_t *pvkey, cx_md_t hashID, cx_ecfp_public_key_t *pukey, unsigned char *a, unsigned int a_len, unsigned char *h, unsigned int h_len)
	Retrieves an EDDSA public key. More...
cx_err_t	cx_edwards_compress_point_no_throw (cx_curve_t curve, uint8_t *p, size_t p_len)
	Compresses a point according to RFC8032 . More...
static void	cx_edwards_compress_point (cx_curve_t curve, uint8_t *p, size_t p_len)
	Compresses a point according to RFC8032 . More...
cx_err_t	cx_edwards_decompress_point_no_throw (cx_curve_t curve, uint8_t *p, size_t p_len)
	Decompresses a point according to RFC8032 . More...
static void	cx_edwards_decompress_point (cx_curve_t curve, uint8_t *p, size_t p_len)
	Decompresses a point according to RFC8032 . More...
static void	cx_edward_compress_point (cx_curve_t curve, uint8_t *p, size_t p_len)
static void	cx_edward_decompress_point (cx_curve_t curve, uint8_t *p, size_t p_len)

Detailed Description

Key pair generation based on elliptic curves.

Private and public keys initialization and key pair generation based on elliptic curves.

Typedef Documentation

cx_ecfp_256_extended_private_key_t

typedef struct cx_ecfp_256_extended_private_key_s cx_ecfp_256_extended_private_key_t

Convenience type.

See cx_ecfp_256_extended_private_key_s.

cx_ecfp_256_private_key_t

typedef struct cx_ecfp_256_private_key_s cx_ecfp_256_private_key_t

temporary def type.

See cx_ecfp_256_private_key_s.

cx_ecfp_256_public_key_t

typedef struct cx_ecfp_256_public_key_s cx_ecfp_256_public_key_t

Convenience type.

See cx_ecfp_256_public_key_s.

cx_ecfp_384_private_key_t

typedef struct cx_ecfp_384_private_key_s cx_ecfp_384_private_key_t

Convenience type.

See cx_ecfp_384_public_key_s.

cx_ecfp_384_public_key_t

typedef struct cx_ecfp_384_public_key_s cx_ecfp_384_public_key_t

Convenience type.

See cx_ecfp_384_private_key_s.

cx_ecfp_512_extented_private_key_t

typedef struct cx_ecfp_512_extented_private_key_s cx_ecfp_512_extented_private_key_t

Convenience type.

See cx_ecfp_512_extented_private_key_s.

cx_ecfp_512_private_key_t

typedef struct cx_ecfp_512_private_key_s cx_ecfp_512_private_key_t

Convenience type.

See cx_ecfp_512_private_key_s.

cx_ecfp_512_public_key_t

typedef struct cx_ecfp_512_public_key_s cx_ecfp_512_public_key_t

Convenience type.

See cx_ecfp_512_public_key_s.

cx_ecfp_640_private_key_t

typedef struct cx_ecfp_640_private_key_s cx_ecfp_640_private_key_t

Convenience type.

See cx_ecfp_640_private_key_s.

cx_ecfp_640_public_key_t

typedef struct cx_ecfp_640_public_key_s cx_ecfp_640_public_key_t

Convenience type.

See cx_ecfp_640_public_key_s.

cx_ecfp_private_key_t

typedef struct cx_ecfp_256_private_key_s cx_ecfp_private_key_t

cx_ecfp_public_key_t

typedef struct cx_ecfp_256_public_key_s cx_ecfp_public_key_t

Function Documentation

cx_ecfp_add_point()

static int cx_ecfp_add_point ( cx_curve_t  curve, unsigned char *  R, const unsigned char *  P, const unsigned char *  Q, unsigned int  X_len  )

Adds two points of an elliptic curve.

This function throws an exception if the computation doesn't succeed.

Warning

It is recommended to use cx_ecfp_add_point_no_throw rather than this function.

Parameters

[in]	curve	Curve identifier.
[out]	R	Resulting point encoded as 04 || x || y.
[in]	P	First operand: point on curve encoded as 04 || x || y: x and y are encoded as big endian raw values and have a binary length equal to curve domain size.
[in]	Q	Second operand: point on curve encoded as 04 || x || y.
[in]	X_len	Length of the x-coordinate. This parameter is not used.

Returns

Length of the encoded point.

Exceptions

CX_EC_INVALID_CURVE

CX_NOT_UNLOCKED

CX_INVALID_PARAMETER_SIZE

CX_EC_INVALID_CURVE

CX_MEMORY_FULL

CX_NOT_LOCKED

CX_INVALID_PARAMETER

CX_EC_INVALID_POINT

CX_EC_INFINITE_POINT

cx_ecfp_add_point_no_throw()

cx_err_t cx_ecfp_add_point_no_throw	(	cx_curve_t	curve,
		uint8_t *	R,
		const uint8_t *	P,
		const uint8_t *	Q
)

Adds two points of an elliptic curve.

Parameters

[in]	curve	Curve identifier.
[out]	R	Resulting point encoded as 04 || x || y.
[in]	P	First operand: point on curve encoded as 04 || x || y: x and y are encoded as big endian raw values and have a binary length equal to curve domain size.
[in]	Q	Second operand: point on curve encoded as 04 || x || y.

Returns

Error code:

• CX_OK on success
• CX_EC_INVALID_CURVE
• CX_NOT_UNLOCKED
• CX_INVALID_PARAMETER_SIZE
• CX_EC_INVALID_CURVE
• CX_MEMORY_FULL
• CX_NOT_LOCKED
• CX_INVALID_PARAMETER
• CX_EC_INVALID_POINT
• CX_EC_INFINITE_POINT

cx_ecfp_generate_pair()

static int cx_ecfp_generate_pair ( cx_curve_t  curve, cx_ecfp_public_key_t *  pubkey, cx_ecfp_private_key_t *  privkey, int  keepprivate  )

Generates a key pair with SHA-512 hash function.

This function throws an exception if the computation doesn't succeed.

Warning

It is recommended to use cx_ecfp_generate_pair_no_throw rather than this function.

Parameters

[in]	curve	Curve identifier.
[out]	pubkey	Generated public key.
[out]	privkey	Generated private key.
[in]	keepprivate	If set, the private key is the one initialized with cx_ecfp_init_private_key_no_throw. Otherwise, a new private key is generated.

Returns

0

Exceptions

CX_EC_INVALID_CURVE

CX_NOT_UNLOCKED

CX_INVALID_PARAMETER_SIZE

CX_MEMORY_FULL

CX_NOT_LOCKED

CX_INVALID_PARAMETER

CX_INTERNAL_ERROR

CX_EC_INVALID_POINT

CX_EC_INFINITE_POINT

cx_ecfp_generate_pair2()

static int cx_ecfp_generate_pair2 ( cx_curve_t  curve, cx_ecfp_public_key_t *  pubkey, cx_ecfp_private_key_t *  privkey, int  keepprivate, cx_md_t  hashID  )

Generates a key pair.

This function throws an exception if the computation doesn't succeed.

Warning

It is recommended to use cx_ecfp_generate_pair2_no_throw rather than this function.

Parameters

[in]	curve	Curve identifier.
[out]	pubkey	Generated public key.
[out]	privkey	Generated private key.
[in]	keepprivate	If set, the private key is the one initialized with cx_ecfp_init_private_key_no_throw. Otherwise, a new private key is generated.
[in]	hashID	Message digest algorithm identifer.

Returns

0

Exceptions

CX_EC_INVALID_CURVE

CX_NOT_UNLOCKED

CX_INVALID_PARAMETER_SIZE

CX_MEMORY_FULL

CX_NOT_LOCKED

CX_INVALID_PARAMETER

CX_INTERNAL_ERROR

CX_EC_INVALID_POINT

CX_EC_INFINITE_POINT

cx_ecfp_generate_pair2_no_throw()

cx_err_t cx_ecfp_generate_pair2_no_throw	(	cx_curve_t	curve,
		cx_ecfp_public_key_t *	pubkey,
		cx_ecfp_private_key_t *	privkey,
		bool	keepprivate,
		cx_md_t	hashID
)

Generates a key pair.

Parameters

[in]	curve	Curve identifier.
[out]	pubkey	Generated public key.
[out]	privkey	Generated private key.
[in]	keepprivate	If set, the private key is the one initialized with cx_ecfp_init_private_key_no_throw. Otherwise, a new private key is generated.
[in]	hashID	Message digest algorithm identifer.

Returns

Error code:

• CX_OK on success
• CX_EC_INVALID_CURVE
• CX_NOT_UNLOCKED
• CX_INVALID_PARAMETER_SIZE
• CX_MEMORY_FULL
• CX_NOT_LOCKED
• CX_INVALID_PARAMETER
• CX_INTERNAL_ERROR
• CX_EC_INVALID_POINT
• CX_EC_INFINITE_POINT

cx_ecfp_generate_pair_no_throw()

cx_err_t cx_ecfp_generate_pair_no_throw	(	cx_curve_t	curve,
		cx_ecfp_public_key_t *	pubkey,
		cx_ecfp_private_key_t *	privkey,
		bool	keepprivate
)

Generates a key pair with SHA-512 hash function.

Parameters

[in]	curve	Curve identifier.
[out]	pubkey	Generated public key.
[out]	privkey	Generated private key.
[in]	keepprivate	If set, the private key is the one initialized with cx_ecfp_init_private_key_no_throw. Otherwise, a new private key is generated.

Returns

Error code:

• CX_OK on success
• CX_EC_INVALID_CURVE
• CX_NOT_UNLOCKED
• CX_INVALID_PARAMETER_SIZE
• CX_MEMORY_FULL
• CX_NOT_LOCKED
• CX_INVALID_PARAMETER
• CX_INTERNAL_ERROR
• CX_EC_INVALID_POINT
• CX_EC_INFINITE_POINT

cx_ecfp_init_private_key()

static int cx_ecfp_init_private_key ( cx_curve_t  curve, const unsigned char *  rawkey, unsigned int  key_len, cx_ecfp_private_key_t *  pvkey  )

Initializes a private key.

The key can be stored in non-volatile memory and used for ECDSA or ECDH processing. This function throws an exception if the computation doesn't succeed.

Warning

It is recommended to use cx_ecfp_init_private_key_no_throw rather than this function.

Parameters

[in]	curve	Curve identifier.
[in]	rawkey	Pointer to a raw key value or NULL pointer. The value shall be in big endian order.
[in]	key_len	Length of the key.
[out]	pvkey	Private key to initialize.

Returns

Length of the key.

Exceptions

CX_EC_INVALID_CURVE

CX_INVALID_PARAMETER

cx_ecfp_init_private_key_no_throw()

cx_err_t cx_ecfp_init_private_key_no_throw	(	cx_curve_t	curve,
		const uint8_t *	rawkey,
		size_t	key_len,
		cx_ecfp_private_key_t *	pvkey
)

Initializes a private key.

The key can be stored in non-volatile memory and used for ECDSA or ECDH processing.

Parameters

[in]	curve	Curve identifier.
[in]	rawkey	Pointer to a raw key value or NULL pointer. The value shall be in big endian order.
[in]	key_len	Length of the key.
[out]	pvkey	Private key to initialize.

Returns

Error code:

• CX_OK on success
• CX_EC_INVALID_CURVE
• CX_INVALID_PARAMETER

cx_ecfp_init_public_key()

static int cx_ecfp_init_public_key ( cx_curve_t  curve, const unsigned char *  rawkey, unsigned int  key_len, cx_ecfp_public_key_t *  key  )

Initializes a public key.

This function throws an exception if the computation doesn't succeed.

Warning

It is recommended to use cx_ecfp_init_public_key_no_throw rather than this function.

Parameters

[in]	curve	Curve identifier.
[in]	rawkey	Pointer to a raw key value or NULL pointer The value shall be the public point encoded as: 04 || x || y for Weiertrass curves 04 || x || y or 02 || y (plus sign) for Twisted Edward curves 04 || x || y or 02 || x for Montgomery curves

where x and y are encoded as big endian raw values and have a binary length equal to the curve domain size.

Parameters

[in]	key_len	Length of the key.
[out]	key	Public key to initialize.

Returns

Length of the key.

Exceptions

CX_EC_INVALID_CURVE

INVALID_PARAMETER

cx_ecfp_init_public_key_no_throw()

cx_err_t cx_ecfp_init_public_key_no_throw	(	cx_curve_t	curve,
		const uint8_t *	rawkey,
		size_t	key_len,
		cx_ecfp_public_key_t *	key
)

Initializes a public key.

Parameters

[in]	curve	Curve identifier.
[in]	rawkey	Pointer to a raw key value or NULL pointer The value shall be the public point encoded as: 04 || x || y for Weiertrass curves 04 || x || y or 02 || y (plus sign) for Twisted Edward curves 04 || x || y or 02 || x for Montgomery curves

where x and y are encoded as big endian raw values and have a binary length equal to the curve domain size.

Parameters

[in]	key_len	Length of the key.
[out]	key	Public key to initialize.

Returns

Error code:

• CX_OK on success
• CX_EC_INVALID_CURVE
• INVALID_PARAMETER

cx_ecfp_scalar_mult()

static int cx_ecfp_scalar_mult ( cx_curve_t  curve, unsigned char *  P, unsigned int  P_len, const unsigned char *  k, unsigned int  k_len  )

Performs a scalar multiplication over an elliptic curve.

This function throws an exception if the computation doesn't succeed.

Warning

It is recommended to use cx_ecfp_scalar_mult_no_throw rather than this function.

Parameters

[in]	curve	Curve identifier.
[in,out]	P	Point on curve encoded as 04 || x || y: x and y are encoded as big endian raw values and have a binary length equal to curve domain size. This is also used for the result.
[in]	P_len	Length of the input point. This parameter is not used.
[in]	k	Scalar encoded as big endian integer.
[in]	k_len	Length of the scalar. This should be equal to the curve domain length.

Returns

Length of the encoded point.

Exceptions

CX_EC_INVALID_CURVE

CX_NOT_UNLOCKED

CX_EC_INVALID_CURVE

CX_MEMORY_FULL

CX_NOT_LOCKED

CX_INVALID_PARAMETER

CX_EC_INFINITE_POINT

cx_ecfp_scalar_mult_no_throw()

cx_err_t cx_ecfp_scalar_mult_no_throw	(	cx_curve_t	curve,
		uint8_t *	P,
		const uint8_t *	k,
		size_t	k_len
)

Performs a scalar multiplication over an elliptic curve.

Parameters

[in]	curve	Curve identifier.
[in,out]	P	Point on curve encoded as 04 || x || y: x and y are encoded as big endian raw values and have a binary length equal to curve domain size. This is also used for the result.
[in]	k	Scalar encoded as big endian integer.
[in]	k_len	Length of the scalar. This should be equal to the curve domain length.

Returns

Error code:

• CX_OK on success
• CX_EC_INVALID_CURVE
• CX_NOT_UNLOCKED
• CX_EC_INVALID_CURVE
• CX_MEMORY_FULL
• CX_NOT_LOCKED
• CX_INVALID_PARAMETER
• CX_EC_INFINITE_POINT

cx_eddsa_get_public_key()

static void cx_eddsa_get_public_key ( const cx_ecfp_private_key_t *  pvkey, cx_md_t  hashID, cx_ecfp_public_key_t *  pukey, unsigned char *  a, unsigned int  a_len, unsigned char *  h, unsigned int  h_len  )

Retrieves an EDDSA public key.

Retrieves (a,h) = (Kr, Kl), such that (Kr, Kl) = Hash(pv_key) as specified at RFC8032 . This function throws an exception if the computation doesn't succeed.

Warning

It is recommended to use cx_eddsa_get_public_key_no_throw rather than this function.

Parameters

[in]	pvkey	A private key fully initialized with cx_ecfp_init_private_key_no_throw.
[in]	hashID	Message digest algorithm identifier used to compute the input data. SHA512, SHA3 and Keccak are supported.
[out]	pukey	Key container for retrieving the public key A.
[out]	a	Private scalar such that A = a.B.
[in]	a_len	Length of the scalar a.
[out]	h	Signature prefix.
[in]	h_len	Length of the prefix h.

Exceptions

CX_EC_INVALID_CURVE

CX_NOT_UNLOCKED

CX_INVALID_PARAMETER_SIZE

CX_INVALID_PARAMETER

CX_NOT_LOCKED

CX_MEMORY_FULL

CX_EC_INVALID_POINT

CX_EC_INFINITE_POINT

CX_INTERNAL_ERROR

cx_eddsa_get_public_key_no_throw()

cx_err_t cx_eddsa_get_public_key_no_throw	(	const cx_ecfp_private_key_t *	pvkey,
		cx_md_t	hashID,
		cx_ecfp_public_key_t *	pukey,
		uint8_t *	a,
		size_t	a_len,
		uint8_t *	h,
		size_t	h_len
)

Retrieves an EDDSA public key.

Retrieves (a,h) = (Kr, Kl), such that (Kr, Kl) = Hash(pv_key) as specified at RFC8032 .

Parameters

[in]	pvkey	A private key fully initialized with cx_ecfp_init_private_key_no_throw.
[in]	hashID	Message digest algorithm identifier used to compute the input data. SHA512, SHA3 and Keccak are supported.
[out]	pukey	Key container for retrieving the public key A.
[out]	a	Private scalar such that A = a.B.
[in]	a_len	Length of the scalar a.
[out]	h	Signature prefix.
[in]	h_len	Length of the prefix h.

Returns

Error code:

• CX_OK on success
• CX_EC_INVALID_CURVE
• CX_NOT_UNLOCKED
• CX_INVALID_PARAMETER_SIZE
• CX_INVALID_PARAMETER
• CX_NOT_LOCKED
• CX_MEMORY_FULL
• CX_EC_INVALID_POINT
• CX_EC_INFINITE_POINT
• CX_INTERNAL_ERROR

cx_edward_compress_point()

static void cx_edward_compress_point ( cx_curve_t  curve, uint8_t *  p, size_t  p_len  )

Deprecated:

See cx_edwards_compress_point_no_throw

cx_edward_decompress_point()

static void cx_edward_decompress_point ( cx_curve_t  curve, uint8_t *  p, size_t  p_len  )

Deprecated:

See cx_edwards_decompress_point_no_throw

cx_edwards_compress_point()

static void cx_edwards_compress_point ( cx_curve_t  curve, uint8_t *  p, size_t  p_len  )

Compresses a point according to RFC8032 .

This function throws an exception if the computation doesn't succeed.

Warning

It is recommended to use cx_edwards_compress_point_no_throw rather than this function.

Parameters

[in]	curve	Curve identifier. The curve must be a Twisted Edwards curve.
[in,out]	p	Pointer to the point to compress.
[in]	p_len	Length of the point buffer.

Exceptions

CX_EC_INVALID_CURVE

CX_NOT_UNLOCKED

CX_INVALID_PARAMETER_SIZE

CX_EC_INVALID_CURVE

CX_MEMORY_FULL

CX_NOT_LOCKED

CX_INVALID_PARAMETER

CX_EC_INFINITE_POINT

cx_edwards_compress_point_no_throw()

cx_err_t cx_edwards_compress_point_no_throw	(	cx_curve_t	curve,
		uint8_t *	p,
		size_t	p_len
)

Compresses a point according to RFC8032 .

Parameters

[in]	curve	Curve identifier. The curve must be a Twisted Edwards curve.
[in,out]	p	Pointer to the point to compress.
[in]	p_len	Length of the point buffer.

Returns

Error code:

• CX_OK on success
• CX_EC_INVALID_CURVE
• CX_NOT_UNLOCKED
• CX_INVALID_PARAMETER_SIZE
• CX_EC_INVALID_CURVE
• CX_MEMORY_FULL
• CX_NOT_LOCKED
• CX_INVALID_PARAMETER
• CX_EC_INFINITE_POINT

cx_edwards_decompress_point()

static void cx_edwards_decompress_point ( cx_curve_t  curve, uint8_t *  p, size_t  p_len  )

Decompresses a point according to RFC8032 .

This function throws an exception if the computation doesn't succeed.

Warning

It is recommended to use cx_edwards_decompress_point_no_throw rather than this function.

Parameters

[in]	curve	Curve identifier. The curve must be a Twisted Edwards curve.
[in,out]	p	Pointer to the point to decompress.
[in]	p_len	Length of the point buffer.

Exceptions

CX_EC_INVALID_CURVE

CX_NOT_UNLOCKED

CX_INVALID_PARAMETER_SIZE

CX_EC_INVALID_CURVE

CX_MEMORY_FULL

CX_NOT_LOCKED

CX_INVALID_PARAMETER

CX_EC_INFINITE_POINT

CX_NO_RESIDUE

INVALID_PARAMETER

cx_edwards_decompress_point_no_throw()

cx_err_t cx_edwards_decompress_point_no_throw	(	cx_curve_t	curve,
		uint8_t *	p,
		size_t	p_len
)

Decompresses a point according to RFC8032 .

Parameters

[in]	curve	Curve identifier. The curve must be a Twisted Edwards curve.
[in,out]	p	Pointer to the point to decompress.
[in]	p_len	Length of the point buffer.

Returns

Error code:

• CX_OK on success
• CX_EC_INVALID_CURVE
• CX_NOT_UNLOCKED
• CX_INVALID_PARAMETER_SIZE
• CX_EC_INVALID_CURVE
• CX_MEMORY_FULL
• CX_NOT_LOCKED
• CX_INVALID_PARAMETER
• CX_EC_INFINITE_POINT
• CX_NO_RESIDUE
• INVALID_PARAMETER

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