[Pkg-bitcoin-commits] [libsecp256k1] 01/37: Add `secp256k1_ec_pubkey_negate` and `secp256k1_ec_privkey_negate`
Jonas Smedegaard
dr at jones.dk
Fri Aug 18 11:27:51 UTC 2017
This is an automated email from the git hooks/post-receive script.
js pushed a commit to branch master
in repository libsecp256k1.
commit 8e48aa60dc9ab9d9b4b417ed520372d4e35b5a31
Author: Andrew Poelstra <apoelstra at wpsoftware.net>
Date: Thu Jul 28 16:05:40 2016 +0000
Add `secp256k1_ec_pubkey_negate` and `secp256k1_ec_privkey_negate`
---
include/secp256k1.h | 22 ++++++++++++++++++++++
src/secp256k1.c | 27 +++++++++++++++++++++++++++
src/tests.c | 26 +++++++++++++++++++++++---
3 files changed, 72 insertions(+), 3 deletions(-)
diff --git a/include/secp256k1.h b/include/secp256k1.h
index 7145dbc..18a7254 100644
--- a/include/secp256k1.h
+++ b/include/secp256k1.h
@@ -491,6 +491,28 @@ SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_create(
const unsigned char *seckey
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
+/** Negates a private key in place.
+ *
+ * Returns: 1 always
+ * Args: ctx: pointer to a context object
+ * In/Out: pubkey: pointer to the public key to be negated (cannot be NULL)
+ */
+SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_privkey_negate(
+ const secp256k1_context* ctx,
+ unsigned char *seckey
+) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2);
+
+/** Negates a public key in place.
+ *
+ * Returns: 1 always
+ * Args: ctx: pointer to a context object
+ * In/Out: pubkey: pointer to the public key to be negated (cannot be NULL)
+ */
+SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_negate(
+ const secp256k1_context* ctx,
+ secp256k1_pubkey *pubkey
+) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2);
+
/** Tweak a private key by adding tweak to it.
* Returns: 0 if the tweak was out of range (chance of around 1 in 2^128 for
* uniformly random 32-byte arrays, or if the resulting private key
diff --git a/src/secp256k1.c b/src/secp256k1.c
index 7973d60..8ca258f 100644
--- a/src/secp256k1.c
+++ b/src/secp256k1.c
@@ -424,6 +424,33 @@ int secp256k1_ec_pubkey_create(const secp256k1_context* ctx, secp256k1_pubkey *p
return ret;
}
+int secp256k1_ec_privkey_negate(const secp256k1_context* ctx, unsigned char *seckey) {
+ secp256k1_scalar sec;
+ VERIFY_CHECK(ctx != NULL);
+ ARG_CHECK(seckey != NULL);
+
+ secp256k1_scalar_set_b32(&sec, seckey, NULL);
+ secp256k1_scalar_negate(&sec, &sec);
+ secp256k1_scalar_get_b32(seckey, &sec);
+
+ return 1;
+}
+
+int secp256k1_ec_pubkey_negate(const secp256k1_context* ctx, secp256k1_pubkey *pubkey) {
+ int ret = 0;
+ secp256k1_ge p;
+ VERIFY_CHECK(ctx != NULL);
+ ARG_CHECK(pubkey != NULL);
+
+ ret = secp256k1_pubkey_load(ctx, &p, pubkey);
+ memset(pubkey, 0, sizeof(*pubkey));
+ if (ret) {
+ secp256k1_ge_neg(&p, &p);
+ secp256k1_pubkey_save(pubkey, &p);
+ }
+ return ret;
+}
+
int secp256k1_ec_privkey_tweak_add(const secp256k1_context* ctx, unsigned char *seckey, const unsigned char *tweak) {
secp256k1_scalar term;
secp256k1_scalar sec;
diff --git a/src/tests.c b/src/tests.c
index b32cb90..21ce055 100644
--- a/src/tests.c
+++ b/src/tests.c
@@ -10,6 +10,7 @@
#include <stdio.h>
#include <stdlib.h>
+#include <string.h>
#include <time.h>
@@ -135,6 +136,7 @@ void random_scalar_order(secp256k1_scalar *num) {
void run_context_tests(void) {
secp256k1_pubkey pubkey;
+ secp256k1_pubkey zero_pubkey;
secp256k1_ecdsa_signature sig;
unsigned char ctmp[32];
int32_t ecount;
@@ -149,6 +151,8 @@ void run_context_tests(void) {
secp256k1_scalar msg, key, nonce;
secp256k1_scalar sigr, sigs;
+ memset(&zero_pubkey, 0, sizeof(zero_pubkey));
+
ecount = 0;
ecount2 = 10;
secp256k1_context_set_illegal_callback(vrfy, counting_illegal_callback_fn, &ecount);
@@ -201,12 +205,20 @@ void run_context_tests(void) {
CHECK(ecount == 2);
CHECK(secp256k1_ec_pubkey_tweak_mul(sign, &pubkey, ctmp) == 0);
CHECK(ecount2 == 13);
- CHECK(secp256k1_ec_pubkey_tweak_mul(vrfy, &pubkey, ctmp) == 1);
+ CHECK(secp256k1_ec_pubkey_negate(vrfy, &pubkey) == 1);
CHECK(ecount == 2);
- CHECK(secp256k1_context_randomize(vrfy, ctmp) == 0);
+ CHECK(secp256k1_ec_pubkey_negate(sign, &pubkey) == 1);
+ CHECK(ecount == 2);
+ CHECK(secp256k1_ec_pubkey_negate(sign, NULL) == 0);
+ CHECK(ecount2 == 14);
+ CHECK(secp256k1_ec_pubkey_negate(vrfy, &zero_pubkey) == 0);
+ CHECK(ecount == 3);
+ CHECK(secp256k1_ec_pubkey_tweak_mul(vrfy, &pubkey, ctmp) == 1);
CHECK(ecount == 3);
+ CHECK(secp256k1_context_randomize(vrfy, ctmp) == 0);
+ CHECK(ecount == 4);
CHECK(secp256k1_context_randomize(sign, NULL) == 1);
- CHECK(ecount2 == 13);
+ CHECK(ecount2 == 14);
secp256k1_context_set_illegal_callback(vrfy, NULL, NULL);
secp256k1_context_set_illegal_callback(sign, NULL, NULL);
@@ -3436,6 +3448,7 @@ void test_ecdsa_end_to_end(void) {
unsigned char pubkeyc[65];
size_t pubkeyclen = 65;
secp256k1_pubkey pubkey;
+ secp256k1_pubkey pubkey_tmp;
unsigned char seckey[300];
size_t seckeylen = 300;
@@ -3457,6 +3470,13 @@ void test_ecdsa_end_to_end(void) {
memset(&pubkey, 0, sizeof(pubkey));
CHECK(secp256k1_ec_pubkey_parse(ctx, &pubkey, pubkeyc, pubkeyclen) == 1);
+ /* Verify negation changes the key and changes it back */
+ memcpy(&pubkey_tmp, &pubkey, sizeof(pubkey));
+ CHECK(secp256k1_ec_pubkey_negate(ctx, &pubkey_tmp) == 1);
+ CHECK(memcmp(&pubkey_tmp, &pubkey, sizeof(pubkey)) != 0);
+ CHECK(secp256k1_ec_pubkey_negate(ctx, &pubkey_tmp) == 1);
+ CHECK(memcmp(&pubkey_tmp, &pubkey, sizeof(pubkey)) == 0);
+
/* Verify private key import and export. */
CHECK(ec_privkey_export_der(ctx, seckey, &seckeylen, privkey, secp256k1_rand_bits(1) == 1));
CHECK(ec_privkey_import_der(ctx, privkey2, seckey, seckeylen) == 1);
--
Alioth's /usr/local/bin/git-commit-notice on /srv/git.debian.org/git/pkg-bitcoin/libsecp256k1.git
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