This file contains the CRYS APIs used for EC MONT (Montgomery Curve25519) algorithms. More...

Data Structures
struct	CRYS_ECMONT_ScalrMultTempBuff_t

struct	CRYS_ECMONT_TempBuff_t

Macros
#define	CRYS_ECMONT_MOD_SIZE_IN_BITS 255U

#define	CRYS_ECMONT_MOD_SIZE_IN_32BIT_WORDS (( CRYS_ECMONT_MOD_SIZE_IN_BITS + SASI_BITS_IN_32BIT_WORD - 1) / SASI_BITS_IN_32BIT_WORD)

#define	CRYS_ECMONT_MOD_SIZE_IN_BYTES (( CRYS_ECMONT_MOD_SIZE_IN_BITS + SASI_BITS_IN_32BIT_WORD - 1) / sizeof(uint32_t))

#define	CRYS_ECMONT_SCALARBYTES (CRYS_ECMONT_MOD_SIZE_IN_32BIT_WORDS * SASI_32BIT_WORD_SIZE)

#define	CRYS_ECMONT_SCALARMULTBYTES (CRYS_ECMONT_MOD_SIZE_IN_32BIT_WORDS * SASI_32BIT_WORD_SIZE)

#define	CRYS_ECMONT_SEEDBYTES (CRYS_ECMONT_MOD_SIZE_IN_32BIT_WORDS * SASI_32BIT_WORD_SIZE)

Enumerations
enum	CRYS_ECMONT_DomainId_t { CRYS_ECMONT_DOMAIN_CURVE_25519 , CRYS_ECMONT_DOMAIN_OFF_MODE , CRYS_ECMONT_DOMAIN_LAST = 0x7FFFFFFF }

Functions
CRYSError_t	CRYS_ECMONT_Scalarmult (uint8_t pResPoint, size_t pResPointSize, const uint8_t pScalar, size_t scalarSize, const uint8_t pInPoint, size_t inPointSize, CRYS_ECMONT_TempBuff_t *pEcMontTempBuff)
	The function performs EC Montgomery (Curve25519) scalar multiplication: resPoint = scalar * point. More...

CRYSError_t	CRYS_ECMONT_ScalarmultBase (uint8_t pResPoint, size_t pResPointSize, const uint8_t pScalar, size_t scalarSize, CRYS_ECMONT_TempBuff_t pEcMontTempBuff)
	The function performs EC Montgomery (Curve25519) scalar multiplication of base point: res = scalar * base_point. More...

CRYSError_t	CRYS_ECMONT_KeyPair (uint8_t pPublKey, size_t pPublKeySize, uint8_t pSecrKey, size_t pSecrKeySize, CRYS_RND_Context_t pRndContext, CRYS_ECMONT_TempBuff_t pEcMontTempBuff)
	The function randomly generates private and public keys for Montgomery Curve25519. More...

CRYSError_t	CRYS_ECMONT_SeedKeyPair (uint8_t pPublKey, size_t pPublKeySize, uint8_t pSecrKey, size_t pSecrKeySize, const uint8_t pSeed, size_t seedSize, CRYS_ECMONT_TempBuff_t pEcMontTempBuff)
	The function generates private and public keys for Montgomery algorithms. More...

Detailed Description

This file contains the CRYS APIs used for EC MONT (Montgomery Curve25519) algorithms.

Note: Implemented algorithms according to Montgomery elliptic curves cryptography, developed by Daniel J.Bernstein etc.

Macro Definition Documentation

#define CRYS_ECMONT_MOD_SIZE_IN_BITS 255U

EC Montgomery curve25519 modulus size in bits, words and bytes

#define CRYS_ECMONT_SCALARBYTES (CRYS_ECMONT_MOD_SIZE_IN_32BIT_WORDS * SASI_32BIT_WORD_SIZE)

Constant sizes of special EC_MONT buffers and arrays

#define CRYS_ECMONT_SEEDBYTES (CRYS_ECMONT_MOD_SIZE_IN_32BIT_WORDS * SASI_32BIT_WORD_SIZE)

EC Montgomery domains ID-s enumerator

Enumeration Type Documentation

enum CRYS_ECMONT_DomainId_t

Enumerator
CRYS_ECMONT_DOMAIN_CURVE_25519	EC Curve25519

Function Documentation

CRYSError_t CRYS_ECMONT_KeyPair	(	uint8_t *	pPublKey ,
		size_t *	pPublKeySize ,
		uint8_t *	pSecrKey ,
		size_t *	pSecrKeySize ,
		CRYS_RND_Context_t *	pRndContext ,
		CRYS_ECMONT_TempBuff_t *	pEcMontTempBuff
	)

The function randomly generates private and public keys for Montgomery Curve25519.

Note

All byte arrays are in LE order of bytes, i.e. LS byte is on the left most place.
LS and MS bits of the Secret key are set according to EC Montgomery scalar mult. algorithm: secrKey[0] &= 248; secrKey[31] &= 127; secrKey[31] |= 64;

Returns: CRYS_OK on success,; A non-zero value on failure as defined crys_ec_mont_edw_error.h.

Parameters

[out]	pPublKey	Pointer to the public key.
[in,out]	pPublKeySize	Pointer to the size of the public key in bytes. In - the size of the buffer must be at least EC order size (for curve25519 - 32 bytes); Out - the actual size.
[out]	pSecrKey	Pointer to the secret key, including.
[in,out]	pSecrKeySize	Pointer to the size of buffer for the secret key in bytes - must be at least EC order size (for curve25519 - 32 bytes).
[in,out]	pRndContext	Pointer to the RND context buffer.
[in]	pEcMontTempBuff	Pointer to the temp buffer, for internal use.

CRYSError_t CRYS_ECMONT_Scalarmult	(	uint8_t *	pResPoint ,
		size_t *	pResPointSize ,
		const uint8_t *	pScalar ,
		size_t	scalarSize ,
		const uint8_t *	pInPoint ,
		size_t	inPointSize ,
		CRYS_ECMONT_TempBuff_t *	pEcMontTempBuff
	)

The function performs EC Montgomery (Curve25519) scalar multiplication: resPoint = scalar * point.

Returns: CRYS_OK on success,; A non-zero value on failure as defined crys_ec_mont_edw_error.h.

Parameters

[out]	pResPoint	Pointer to the public (secret) key.
[in,out]	pResPointSize	Pointer to the size of the public key in bytes. In - the size of the buffer. must be at least EC modulus size (for curve25519 - 32 bytes). Out - the actual size.
[in]	pScalar	Pointer to the secret (private) key.
[in]	scalarSize	Pointer to the size of the secret key in bytes; must be equal to EC order size (for curve25519 - 32 bytes).
[in]	pInPoint	Pointer to the input point (compressed).
[in]	inPointSize	Size of the point - must be equal to CRYS_ECMONT_MOD_SIZE_IN_BYTES.
[in]	pEcMontTempBuff	Pointer to temp buffer, for internal use.

CRYSError_t CRYS_ECMONT_ScalarmultBase	(	uint8_t *	pResPoint ,
		size_t *	pResPointSize ,
		const uint8_t *	pScalar ,
		size_t	scalarSize ,
		CRYS_ECMONT_TempBuff_t *	pEcMontTempBuff
	)

The function performs EC Montgomery (Curve25519) scalar multiplication of base point: res = scalar * base_point.

   Note: all byte arrays have LE order of bytes, i.e. LS byte is on left most place.

Returns: CRYS_OK on success,; A non-zero value on failure as defined crys_ec_mont_edw_error.h.

Parameters

[out]	pResPoint	Pointer to the public (secret) key.
[in,out]	pResPointSize	Pointer to the size of the public key in bytes. In - the size of buffer must be at least EC modulus size (for curve25519 - 32 bytes); Out - the actual size.
[in]	pScalar	Pointer to the secret (private) key.
[in]	scalarSize	Pointer to the size of the scalar in bytes - must be equal to EC order size (for curve25519 - 32 bytes).
[in]	pEcMontTempBuff	Pointer to temp buffer, for internal use.

CRYSError_t CRYS_ECMONT_SeedKeyPair	(	uint8_t *	pPublKey ,
		size_t *	pPublKeySize ,
		uint8_t *	pSecrKey ,
		size_t *	pSecrKeySize ,
		const uint8_t *	pSeed ,
		size_t	seedSize ,
		CRYS_ECMONT_TempBuff_t *	pEcMontTempBuff
	)

The function generates private and public keys for Montgomery algorithms.

   The generation performed using given seed.

Returns: CRYS_OK on success,; A non-zero value on failure as defined crys_ec_mont_edw_error.h.

Parameters

[out]	pPublKey	Pointer to the public (secret) key.
[in,out]	pPublKeySize	Pointer to the size of the public key in bytes. In - the size of buffer must be at least EC order size (for curve25519 - 32 bytes); Out - the actual size.
[out]	pSecrKey	Pointer to the secret (private) key.
[in,out]	pSecrKeySize	Pointer to the size of the secret key in bytes In - the size of buffer must be at least EC order size (for curve25519 - 32 bytes); Out - the actual size.
[in]	pSeed	Pointer to the given seed - 32 bytes.
[in]	seedSize	Size of the seed in bytes (must be equal to CRYS_ECMONT_SEEDBYTES).
[in]	pEcMontTempBuff	Pointer to a temp buffer, for internal use.

crys_ec_mont_api

nRF5 SDK v14.2.0

Data Structures

Macros

Enumerations

Functions

Detailed Description

Macro Definition Documentation

Enumeration Type Documentation

Function Documentation