Functions
int	curve25519_mult (byte publicKey[32], const byte secretKey[32])
	Generate a public key.

int	curve25519_mult (byte sharedKey[32], const byte secretKey[32], const byte othersKey[32])
	Generate a shared key.

int	ed25519_publickey (byte publicKey[32], const byte secretKey[32])
	Creates a public key from a secret key.

int	ed25519_sign (const byte *message, size_t messageLength, const byte secretKey[32], const byte publicKey[32], byte signature[64])
	Creates a signature on a message.

int	ed25519_sign (std::istream &stream, const byte secretKey[32], const byte publicKey[32], byte signature[64])
	Creates a signature on a message.

int	ed25519_sign_open (const byte *message, size_t messageLength, const byte publicKey[32], const byte signature[64])
	Verifies a signature on a message.

int	ed25519_sign_open (std::istream &stream, const byte publicKey[32], const byte signature[64])
	Verifies a signature on a message.

Detailed Description

Functions for curve25519 and ed25519 operations

This header provides the entry points into Andrew Moon's curve25519 and ed25519 curve functions. The Crypto++ classes x25519 and ed25519 use the functions. The functions are in the Donna namespace and are curve25519_mult(), ed25519_publickey(), ed25519_sign() and ed25519_sign_open().

At the moment the hash function for signing is fixed at SHA512.

Definition in file donna.h.

Function Documentation

◆ curve25519_mult() [1/2]

int curve25519_mult	(	byte	publicKey[32],
		const byte	secretKey[32] )

Generate a public key.

Parameters

publicKey	byte array for the public key
secretKey	byte array with the private key

Returns: 0 on success, non-0 otherwise

curve25519_mult() generates a public key from an existing secret key. Internally curve25519_mult() performs a scalar multiplication using the base point and writes the result to pubkey.

◆ curve25519_mult() [2/2]

int curve25519_mult	(	byte	sharedKey[32],
		const byte	secretKey[32],
		const byte	othersKey[32] )

Generate a shared key.

Parameters

sharedKey	byte array for the shared secret
secretKey	byte array with the private key
othersKey	byte array with the peer's public key

Returns: 0 on success, non-0 otherwise

curve25519_mult() generates a shared key from an existing secret key and the other party's public key. Internally curve25519_mult() performs a scalar multiplication using the two keys and writes the result to sharedKey.

◆ ed25519_publickey()

int ed25519_publickey	(	byte	publicKey[32],
		const byte	secretKey[32] )

Creates a public key from a secret key.

Parameters

publicKey	byte array for the public key
secretKey	byte array with the private key

Returns: 0 on success, non-0 otherwise

ed25519_publickey() generates a public key from a secret key. Internally ed25519_publickey() performs a scalar multiplication using the secret key and then writes the result to publicKey.

◆ ed25519_sign() [1/2]

int ed25519_sign	(	const byte *	message,
		size_t	messageLength,
		const byte	secretKey[32],
		const byte	publicKey[32],
		byte	signature[64] )

Creates a signature on a message.

Parameters

message	byte array with the message
messageLength	size of the message, in bytes
publicKey	byte array with the public key
secretKey	byte array with the private key
signature	byte array for the signature

Returns: 0 on success, non-0 otherwise

ed25519_sign() generates a signature on a message using the public and private keys. The various buffers can be exact sizes, and do not require extra space like when using the NaCl library functions.

At the moment the hash function for signing is fixed at SHA512.

◆ ed25519_sign() [2/2]

int ed25519_sign	(	std::istream &	stream,
		const byte	secretKey[32],
		const byte	publicKey[32],
		byte	signature[64] )

Creates a signature on a message.

Parameters

stream	std::istream derived class
publicKey	byte array with the public key
secretKey	byte array with the private key
signature	byte array for the signature

Returns: 0 on success, non-0 otherwise

ed25519_sign() generates a signature on a message using the public and private keys. The various buffers can be exact sizes, and do not require extra space like when using the NaCl library functions.

This ed25519_sign() overload handles large streams. It was added for signing and verifying files that are too large for a memory allocation.

At the moment the hash function for signing is fixed at SHA512.

◆ ed25519_sign_open() [1/2]

int ed25519_sign_open	(	const byte *	message,
		size_t	messageLength,
		const byte	publicKey[32],
		const byte	signature[64] )

Verifies a signature on a message.

Parameters

message	byte array with the message
messageLength	size of the message, in bytes
publicKey	byte array with the public key
signature	byte array with the signature

Returns: 0 on success, non-0 otherwise

ed25519_sign_open() verifies a signature on a message using the public key. The various buffers can be exact sizes, and do not require extra space like when using the NaCl library functions.

At the moment the hash function for signing is fixed at SHA512.

◆ ed25519_sign_open() [2/2]

int ed25519_sign_open	(	std::istream &	stream,
		const byte	publicKey[32],
		const byte	signature[64] )

Verifies a signature on a message.

Parameters

stream	std::istream derived class
publicKey	byte array with the public key
signature	byte array with the signature

Returns: 0 on success, non-0 otherwise

ed25519_sign_open() verifies a signature on a message using the public key. The various buffers can be exact sizes, and do not require extra space like when using the NaCl library functions.

This ed25519_sign_open() overload handles large streams. It was added for signing and verifying files that are too large for a memory allocation.

At the moment the hash function for signing is fixed at SHA512.