7 #ifndef SECP256K1_MODULE_ECDH_MAIN_H 8 #define SECP256K1_MODULE_ECDH_MAIN_H 10 #include "../../../include/secp256k1_ecdh.h" 11 #include "../../ecmult_const_impl.h" 13 static int ecdh_hash_function_sha256(
unsigned char *output,
const unsigned char *x32,
const unsigned char *y32,
void *data) {
14 unsigned char version = (y32[31] & 0x01) | 0x02;
18 secp256k1_sha256_initialize(&sha);
19 secp256k1_sha256_write(&sha, &
version, 1);
20 secp256k1_sha256_write(&sha, x32, 32);
21 secp256k1_sha256_finalize(&sha, output);
39 ARG_CHECK(output != NULL);
40 ARG_CHECK(point != NULL);
41 ARG_CHECK(scalar != NULL);
47 secp256k1_pubkey_load(ctx, &pt, point);
48 secp256k1_scalar_set_b32(&s, scalar, &overflow);
50 overflow |= secp256k1_scalar_is_zero(&s);
51 secp256k1_scalar_cmov(&s, &secp256k1_scalar_one, overflow);
53 secp256k1_ecmult_const(&
res, &pt, &s, 256);
54 secp256k1_ge_set_gej(&pt, &
res);
57 secp256k1_fe_normalize(&pt.
x);
58 secp256k1_fe_normalize(&pt.
y);
59 secp256k1_fe_get_b32(x, &pt.
x);
60 secp256k1_fe_get_b32(y, &pt.
y);
62 ret = hashfp(output, x, y, data);
66 secp256k1_scalar_clear(&s);
68 return !!ret & !overflow;
#define VERIFY_CHECK(cond)
int secp256k1_ecdh(const secp256k1_context *ctx, unsigned char *output, const secp256k1_pubkey *point, const unsigned char *scalar, secp256k1_ecdh_hash_function hashfp, void *data)
struct secp256k1_context_struct secp256k1_context
const secp256k1_ecdh_hash_function secp256k1_ecdh_hash_function_sha256
const secp256k1_ecdh_hash_function secp256k1_ecdh_hash_function_default
version
Supported socks variants.
int(* secp256k1_ecdh_hash_function)(unsigned char *output, const unsigned char *x32, const unsigned char *y32, void *data)