mirror of
https://github.com/jb55/nostril.git
synced 2024-05-19 11:12:31 -04:00
64 lines
2.5 KiB
C
64 lines
2.5 KiB
C
#ifndef SECP256K1_ECDH_H
|
|
#define SECP256K1_ECDH_H
|
|
|
|
#include "secp256k1.h"
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
/** A pointer to a function that hashes an EC point to obtain an ECDH secret
|
|
*
|
|
* Returns: 1 if the point was successfully hashed.
|
|
* 0 will cause secp256k1_ecdh to fail and return 0.
|
|
* Other return values are not allowed, and the behaviour of
|
|
* secp256k1_ecdh is undefined for other return values.
|
|
* Out: output: pointer to an array to be filled by the function
|
|
* In: x32: pointer to a 32-byte x coordinate
|
|
* y32: pointer to a 32-byte y coordinate
|
|
* data: arbitrary data pointer that is passed through
|
|
*/
|
|
typedef int (*secp256k1_ecdh_hash_function)(
|
|
unsigned char *output,
|
|
const unsigned char *x32,
|
|
const unsigned char *y32,
|
|
void *data
|
|
);
|
|
|
|
/** An implementation of SHA256 hash function that applies to compressed public key.
|
|
* Populates the output parameter with 32 bytes. */
|
|
SECP256K1_API_VAR const secp256k1_ecdh_hash_function secp256k1_ecdh_hash_function_sha256;
|
|
|
|
/** A default ECDH hash function (currently equal to secp256k1_ecdh_hash_function_sha256).
|
|
* Populates the output parameter with 32 bytes. */
|
|
SECP256K1_API_VAR const secp256k1_ecdh_hash_function secp256k1_ecdh_hash_function_default;
|
|
|
|
/** Compute an EC Diffie-Hellman secret in constant time
|
|
*
|
|
* Returns: 1: exponentiation was successful
|
|
* 0: scalar was invalid (zero or overflow) or hashfp returned 0
|
|
* Args: ctx: pointer to a context object.
|
|
* Out: output: pointer to an array to be filled by hashfp.
|
|
* In: pubkey: a pointer to a secp256k1_pubkey containing an initialized public key.
|
|
* seckey: a 32-byte scalar with which to multiply the point.
|
|
* hashfp: pointer to a hash function. If NULL,
|
|
* secp256k1_ecdh_hash_function_sha256 is used
|
|
* (in which case, 32 bytes will be written to output).
|
|
* data: arbitrary data pointer that is passed through to hashfp
|
|
* (can be NULL for secp256k1_ecdh_hash_function_sha256).
|
|
*/
|
|
SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ecdh(
|
|
const secp256k1_context *ctx,
|
|
unsigned char *output,
|
|
const secp256k1_pubkey *pubkey,
|
|
const unsigned char *seckey,
|
|
secp256k1_ecdh_hash_function hashfp,
|
|
void *data
|
|
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4);
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif /* SECP256K1_ECDH_H */
|