frost/secp256k1-zkp
3
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Merge bitcoin-core/secp256k1#1350: scalar: introduce and use secp256k1_{read,write}_be64 helpers

Browse Source 
7067ee54b4206c26b382980f3c20b5fa0262a23a tests: add tests for `secp256k1_{read,write}_be64` (Sebastian Falbesoner)
740528caad8c37e335cba2bcd02790d94c22e767 scalar: use newly introduced `secp256k1_{read,write}_be64` helpers (4x64 impl.) (Sebastian Falbesoner)

Pull request description:

  This is a simple follow-up to #1339, as suggested in comment https://github.com/bitcoin-core/secp256k1/pull/1339#issuecomment-1587508040.

ACKs for top commit:
  stratospher:
    ACK 7067ee5.
  real-or-random:
    utACK 7067ee54b4206c26b382980f3c20b5fa0262a23a

Tree-SHA512: f9bc2ab610099948ffac1e6bb3c822bd90b81a7110ab74cec03175e2c92ed27694a15f9cdaa7c4f1b460fe459f61c3d1d102c99592169f127fdd7539a1a0c154
This commit is contained in:
Tim Ruffing 2023-06-18 20:33:31 +02:00
commit 45c5ca7675
No known key found for this signature in database
GPG Key ID: 8C461CCD293F6011
3 changed files with 55 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
src/scalar_4x64_impl.h
View File

@ -133,10 +133,10 @@ static void secp256k1_scalar_cadd_bit(secp256k1_scalar *r, unsigned int bit, int
static void secp256k1_scalar_set_b32(secp256k1_scalar *r, const unsigned char *b32, int *overflow) { static void secp256k1_scalar_set_b32(secp256k1_scalar *r, const unsigned char *b32, int *overflow) {
int over; int over;
r->d[0] = ((uint64_t)secp256k1_read_be32(&b32[24]) << 32) | (uint64_t)secp256k1_read_be32(&b32[28]); r->d[0] = secp256k1_read_be64(&b32[24]);
r->d[1] = ((uint64_t)secp256k1_read_be32(&b32[16]) << 32) | (uint64_t)secp256k1_read_be32(&b32[20]); r->d[1] = secp256k1_read_be64(&b32[16]);
r->d[2] = ((uint64_t)secp256k1_read_be32(&b32[8]) << 32) | (uint64_t)secp256k1_read_be32(&b32[12]); r->d[2] = secp256k1_read_be64(&b32[8]);
r->d[3] = ((uint64_t)secp256k1_read_be32(&b32[0]) << 32) | (uint64_t)secp256k1_read_be32(&b32[4]); r->d[3] = secp256k1_read_be64(&b32[0]);
over = secp256k1_scalar_reduce(r, secp256k1_scalar_check_overflow(r)); over = secp256k1_scalar_reduce(r, secp256k1_scalar_check_overflow(r));
if (overflow) { if (overflow) {
*overflow = over; *overflow = over;
@ -144,10 +144,10 @@ static void secp256k1_scalar_set_b32(secp256k1_scalar *r, const unsigned char *b
} }
static void secp256k1_scalar_get_b32(unsigned char *bin, const secp256k1_scalar* a) { static void secp256k1_scalar_get_b32(unsigned char *bin, const secp256k1_scalar* a) {
secp256k1_write_be32(&bin[0], a->d[3] >> 32); secp256k1_write_be32(&bin[4], a->d[3]); secp256k1_write_be64(&bin[0], a->d[3]);
secp256k1_write_be32(&bin[8], a->d[2] >> 32); secp256k1_write_be32(&bin[12], a->d[2]); secp256k1_write_be64(&bin[8], a->d[2]);
secp256k1_write_be32(&bin[16], a->d[1] >> 32); secp256k1_write_be32(&bin[20], a->d[1]); secp256k1_write_be64(&bin[16], a->d[1]);
secp256k1_write_be32(&bin[24], a->d[0] >> 32); secp256k1_write_be32(&bin[28], a->d[0]); secp256k1_write_be64(&bin[24], a->d[0]);
} }
SECP256K1_INLINE static int secp256k1_scalar_is_zero(const secp256k1_scalar *a) { SECP256K1_INLINE static int secp256k1_scalar_is_zero(const secp256k1_scalar *a) {

31
src/tests.c
View File

@ -7516,16 +7516,31 @@ static void run_secp256k1_memczero_test(void) {
} }
static void run_secp256k1_byteorder_tests(void) { static void run_secp256k1_byteorder_tests(void) {
const uint32_t x = 0xFF03AB45; {
const unsigned char x_be[4] = {0xFF, 0x03, 0xAB, 0x45}; const uint32_t x = 0xFF03AB45;
unsigned char buf[4]; const unsigned char x_be[4] = {0xFF, 0x03, 0xAB, 0x45};
uint32_t x_; unsigned char buf[4];
uint32_t x_;
secp256k1_write_be32(buf, x); secp256k1_write_be32(buf, x);
CHECK(secp256k1_memcmp_var(buf, x_be, sizeof(buf)) == 0); CHECK(secp256k1_memcmp_var(buf, x_be, sizeof(buf)) == 0);
x_ = secp256k1_read_be32(buf); x_ = secp256k1_read_be32(buf);
CHECK(x == x_); CHECK(x == x_);
}
{
const uint64_t x = 0xCAFE0123BEEF4567;
const unsigned char x_be[8] = {0xCA, 0xFE, 0x01, 0x23, 0xBE, 0xEF, 0x45, 0x67};
unsigned char buf[8];
uint64_t x_;
secp256k1_write_be64(buf, x);
CHECK(secp256k1_memcmp_var(buf, x_be, sizeof(buf)) == 0);
x_ = secp256k1_read_be64(buf);
CHECK(x == x_);
}
} }
static void int_cmov_test(void) { static void int_cmov_test(void) {

24
src/util.h
View File

@ -353,4 +353,28 @@ SECP256K1_INLINE static void secp256k1_write_be32(unsigned char* p, uint32_t x)
p[0] = x >> 24; p[0] = x >> 24;
} }
/* Read a uint64_t in big endian */
SECP256K1_INLINE static uint64_t secp256k1_read_be64(const unsigned char* p) {
return (uint64_t)p[0] << 56 |
(uint64_t)p[1] << 48 |
(uint64_t)p[2] << 40 |
(uint64_t)p[3] << 32 |
(uint64_t)p[4] << 24 |
(uint64_t)p[5] << 16 |
(uint64_t)p[6] << 8 |
(uint64_t)p[7];
}
/* Write a uint64_t in big endian */
SECP256K1_INLINE static void secp256k1_write_be64(unsigned char* p, uint64_t x) {
p[7] = x;
p[6] = x >> 8;
p[5] = x >> 16;
p[4] = x >> 24;
p[3] = x >> 32;
p[2] = x >> 40;
p[1] = x >> 48;
p[0] = x >> 56;
}
#endif /* SECP256K1_UTIL_H */ #endif /* SECP256K1_UTIL_H */