lcx_ecschnorr.h

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ECSDSA (Elliptic Curve-based Schnorr Digital Signature Algorithm). More...

Functions
cx_err_t	cx_ecschnorr_sign_no_throw (const cx_ecfp_private_key_t *pvkey, uint32_t mode, cx_md_t hashID, const uint8_t *msg, size_t msg_len, uint8_t *sig, size_t *sig_len)
	Signs a digest message according to the given mode. More...
static int	cx_ecschnorr_sign (const cx_ecfp_private_key_t *pvkey, int mode, cx_md_t hashID, const unsigned char *msg, unsigned int msg_len, unsigned char *sig, size_t sig_len, unsigned int *info)
	Signs a digest message according to the given mode. More...
bool	cx_ecschnorr_verify (const cx_ecfp_public_key_t *pukey, uint32_t mode, cx_md_t hashID, const uint8_t *msg, size_t msg_len, const uint8_t *sig, size_t sig_len)
	Verifies a digest message signature according to the given mode. More...

Detailed Description

ECSDSA (Elliptic Curve-based Schnorr Digital Signature Algorithm).

Schnorr signature algorithm is a non-standard alternative to ECDSA. Several implementations of Schnorr signature algorithm are supported here.

Function Documentation

cx_ecschnorr_sign()

static int cx_ecschnorr_sign ( const cx_ecfp_private_key_t *  pvkey, int  mode, cx_md_t  hashID, const unsigned char *  msg, unsigned int  msg_len, unsigned char *  sig, size_t  sig_len, unsigned int *  info  )

Signs a digest message according to the given mode.

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

Warning

It is recommended to use cx_ecschnorr_sign_no_throw rather than this function.

Parameters

[in]	pvkey	Pointer to the private key initialized with cx_ecfp_init_private_key_no_throw beforehand.
[in]	mode	Mode. Supported flag: CX_ECSCHNORR_XY CX_ECSCHNORR_ISO14888_X CX_ECSCHNORR_BSI03111 CX_ECSCHNORR_LIBSECP CX_ECSCHNORR_Z CX_ECSCHNORR_BIP0340
[in]	hashID	Message digest algorithm identifier. This parameter is mandatory when using the CX_RND_RFC6979 pseudorandom number generator.
[in]	msg	Input data to sign.
[in]	msg_len	Length of input data.
[out]	sig	ECSchnorr signature encoded in TLV: 30 || L || 02 || Lr || r || 02 || Ls || s. This parameter holds the auxiliary random data when CX_ECSCHNORR_BIP0340 is used.
[in]	sig_len	Length of the signature.
[in]	info	Additional information. This parameter is not used.

Returns

Length of the signature.

Exceptions

CX_EC_INVALID_CURVE

CX_INVALID_PARAMETER

CX_NOT_UNLOCKED

CX_INVALID_PARAMETER_SIZE

CX_NOT_LOCKED

CX_MEMORY_FULL

CX_EC_INVALID_POINT

CX_EC_INFINITE_POINT

CX_INVALID_PARAMETER_VALUE

cx_ecschnorr_sign_no_throw()

cx_err_t cx_ecschnorr_sign_no_throw	(	const cx_ecfp_private_key_t *	pvkey,
		uint32_t	mode,
		cx_md_t	hashID,
		const uint8_t *	msg,
		size_t	msg_len,
		uint8_t *	sig,
		size_t *	sig_len
)

Signs a digest message according to the given mode.

Parameters

[in]	pvkey	Pointer to the private key initialized with cx_ecfp_init_private_key_no_throw beforehand.
[in]	mode	Mode. Supported flag: CX_ECSCHNORR_XY CX_ECSCHNORR_ISO14888_X CX_ECSCHNORR_BSI03111 CX_ECSCHNORR_LIBSECP CX_ECSCHNORR_Z CX_ECSCHNORR_BIP0340
[in]	hashID	Message digest algorithm identifier. This parameter is mandatory when using the CX_RND_RFC6979 pseudorandom number generator.
[in]	msg	Input data to sign.
[in]	msg_len	Length of input data.
[out]	sig	ECSchnorr signature encoded in TLV: 30 || L || 02 || Lr || r || 02 || Ls || s. This parameter holds the auxiliary random data when CX_ECSCHNORR_BIP0340 is used.
[in]	sig_len	Length of the signature.

Returns

Error code:

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

cx_ecschnorr_verify()

bool cx_ecschnorr_verify	(	const cx_ecfp_public_key_t *	pukey,
		uint32_t	mode,
		cx_md_t	hashID,
		const uint8_t *	msg,
		size_t	msg_len,
		const uint8_t *	sig,
		size_t	sig_len
)

Verifies a digest message signature according to the given mode.

Parameters

[in]	pukey	Pointer to the public key initialized with cx_ecfp_init_private_key_no_throw beforehand.
[in]	mode	Mode. Supported flag: CX_ECSCHNORR_XY CX_ECSCHNORR_ISO14888_X CX_ECSCHNORR_BSI03111 CX_ECSCHNORR_LIBSECP CX_ECSCHNORR_Z CX_ECSCHNORR_BIP0340
[in]	hashID	Message digest algorithm identifier used to compute the input data.
[in]	msg	Signed input data to verify the signature.
[in]	msg_len	Length of the input data.
[in]	sig	ECSchnorr signature to verify encoded in TLV: 30 || L || 02 || Lr || r || 02 || Ls || s
[in]	sig_len	Length of the signature.

Returns

1 if signature is verified, 0 otherwise.

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