ecc_libsecp256k1.c File Reference

#include "secp256k1/include/secp256k1.h"
#include <assert.h>
#include <stdint.h>
#include <string.h>
#include "btc/btc.h"
#include "random.h"

Go to the source code of this file.

Functions
void	ecc_start (void)
	init static ecc context More...
void	ecc_stop (void)
	destroys the static ecc context More...
void	ecc_get_pubkey (const uint8_t *private_key, uint8_t *public_key, size_t *in_outlen, btc_bool compressed)
	get public key from given private key More...
btc_bool	ecc_private_key_tweak_add (uint8_t *private_key, const uint8_t *tweak)
	ec mul tweak on given private key More...
btc_bool	ecc_public_key_tweak_add (uint8_t *public_key_inout, const uint8_t *tweak)
	ec mul tweak on given public key More...
btc_bool	ecc_verify_privatekey (const uint8_t *private_key)
	verifies a given 32byte key More...
btc_bool	ecc_verify_pubkey (const uint8_t *public_key, btc_bool compressed)
	verifies a given public key (compressed[33] or uncompressed[65] bytes) More...
btc_bool	ecc_sign (const uint8_t *private_key, const uint8_t *hash, unsigned char *sigder, size_t *outlen)
btc_bool	ecc_verify_sig (const uint8_t *public_key, btc_bool compressed, const uint8_t *hash, unsigned char *sigder, size_t siglen)

Variables
static secp256k1_context *	secp256k1_ctx = NULL

Function Documentation

void ecc_get_pubkey	(	const uint8_t *	private_key,
		uint8_t *	public_key,
		size_t *	in_outlen,
		btc_bool	compressed
	)

get public key from given private key

Definition at line 36 of file ecc_libsecp256k1.c.

References secp256k1_ctx.

Referenced by btc_hdnode_fill_public_key(), and btc_pubkey_from_key().

{
    secp256k1_pubkey pubkey;
    assert(secp256k1_ctx);
    assert((int)*in_outlen == (compressed ? 33 : 65));
    memset(public_key, 0, *in_outlen);

    if (!secp256k1_ec_pubkey_create(secp256k1_ctx, &pubkey, (const unsigned char*)private_key)) {
        return;
    }

    if (!secp256k1_ec_pubkey_serialize(secp256k1_ctx, public_key, in_outlen, &pubkey, compressed)) {
        return;
    }

    return;
}

btc_bool ecc_private_key_tweak_add	(	uint8_t *	private_key,
		const uint8_t *	tweak
	)

ec mul tweak on given private key

Definition at line 54 of file ecc_libsecp256k1.c.

References secp256k1_ctx.

Referenced by btc_hdnode_private_ckd().

{
    assert(secp256k1_ctx);
    return secp256k1_ec_privkey_tweak_add(secp256k1_ctx, (unsigned char*)private_key, (const unsigned char*)tweak);
}

btc_bool ecc_public_key_tweak_add	(	uint8_t *	public_key_inout,
		const uint8_t *	tweak
	)

ec mul tweak on given public key

Definition at line 60 of file ecc_libsecp256k1.c.

References secp256k1_ctx.

Referenced by btc_hdnode_public_ckd().

{
    size_t out;
    secp256k1_pubkey pubkey;

    assert(secp256k1_ctx);
    if (!secp256k1_ec_pubkey_parse(secp256k1_ctx, &pubkey, public_key_inout, 33))
        return false;

    if (!secp256k1_ec_pubkey_tweak_add(secp256k1_ctx, &pubkey, (const unsigned char*)tweak))
        return false;

    if (!secp256k1_ec_pubkey_serialize(secp256k1_ctx, public_key_inout, &out, &pubkey, SECP256K1_EC_COMPRESSED))
        return false;

    return true;
}

btc_bool ecc_sign	(	const uint8_t *	private_key,
		const uint8_t *	hash,
		unsigned char *	sigder,
		size_t *	outlen
	)

Definition at line 99 of file ecc_libsecp256k1.c.

References secp256k1_ctx.

Referenced by btc_key_sign_hash().

{
    assert(secp256k1_ctx);

    secp256k1_ecdsa_signature sig;
    if (!secp256k1_ecdsa_sign(secp256k1_ctx, &sig, hash, private_key, secp256k1_nonce_function_rfc6979, NULL))
        return 0;

    if (!secp256k1_ecdsa_signature_serialize_der(secp256k1_ctx, sigder, outlen, &sig))
        return 0;

    return 1;
}

void ecc_start

(

void

)

init static ecc context

Definition at line 13 of file ecc_libsecp256k1.c.

References random_bytes(), and secp256k1_ctx.

{
    secp256k1_ctx = secp256k1_context_create(SECP256K1_CONTEXT_SIGN | SECP256K1_CONTEXT_VERIFY);
    assert(secp256k1_ctx != NULL);

    uint8_t seed[32];
    random_bytes(seed, 32, 0);
    int ret = secp256k1_context_randomize(secp256k1_ctx, seed);
    assert(ret);
}

void ecc_stop

(

void

)

destroys the static ecc context

Definition at line 25 of file ecc_libsecp256k1.c.

References secp256k1_ctx.

{
    secp256k1_context* ctx = secp256k1_ctx;
    secp256k1_ctx = NULL;

    if (ctx) {
        secp256k1_context_destroy(ctx);
    }
}

btc_bool ecc_verify_privatekey

(

const uint8_t *

private_key

)

verifies a given 32byte key

Definition at line 79 of file ecc_libsecp256k1.c.

References secp256k1_ctx.

Referenced by btc_hdnode_from_seed(), btc_hdnode_private_ckd(), btc_privkey_gen(), and btc_privkey_is_valid().

{
    assert(secp256k1_ctx);
    return secp256k1_ec_seckey_verify(secp256k1_ctx, (const unsigned char*)private_key);
}

btc_bool ecc_verify_pubkey	(	const uint8_t *	public_key,
		btc_bool	compressed
	)

verifies a given public key (compressed[33] or uncompressed[65] bytes)

Definition at line 85 of file ecc_libsecp256k1.c.

References secp256k1_ctx.

Referenced by btc_pubkey_is_valid().

{
    secp256k1_pubkey pubkey;

    assert(secp256k1_ctx);
    if (!secp256k1_ec_pubkey_parse(secp256k1_ctx, &pubkey, public_key, compressed ? 33 : 65)) {
        memset(&pubkey, 0, sizeof(pubkey));
        return false;
    }

    memset(&pubkey, 0, sizeof(pubkey));
    return true;
}

btc_bool ecc_verify_sig	(	const uint8_t *	public_key,
		btc_bool	compressed,
		const uint8_t *	hash,
		unsigned char *	sigder,
		size_t	siglen
	)

Definition at line 113 of file ecc_libsecp256k1.c.

References secp256k1_ctx.

Referenced by btc_pubkey_verify_sig().

{
    assert(secp256k1_ctx);

    secp256k1_ecdsa_signature sig;
    secp256k1_pubkey pubkey;

    if (!secp256k1_ec_pubkey_parse(secp256k1_ctx, &pubkey, public_key, compressed ? 33 : 65))
        return false;

    if (!secp256k1_ecdsa_signature_parse_der(secp256k1_ctx, &sig, sigder, siglen))
        return false;

    return secp256k1_ecdsa_verify(secp256k1_ctx, &sig, hash, &pubkey);
}

Variable Documentation

secp256k1_context* secp256k1_ctx = NULL

static

Definition at line 11 of file ecc_libsecp256k1.c.

Referenced by ecc_get_pubkey(), ecc_private_key_tweak_add(), ecc_public_key_tweak_add(), ecc_sign(), ecc_start(), ecc_stop(), ecc_verify_privatekey(), ecc_verify_pubkey(), and ecc_verify_sig().