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C89 nits and dead code removal.

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This commit is contained in:
Gregory Maxwell 2015-01-23 04:17:12 +00:00
parent a9f350d309
commit 3627437d80
8 changed files with 32 additions and 39 deletions
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4
src/ecdsa.h
View file

@ -10,9 +10,6 @@
#include "scalar.h"
#include "group.h"
static void secp256k1_ecsda_start(void);
static void secp256k1_ecdsa_stop(void);
typedef struct {
secp256k1_scalar_t r, s;
} secp256k1_ecdsa_sig_t;
@ -22,6 +19,5 @@ static int secp256k1_ecdsa_sig_serialize(unsigned char *sig, int *size, const se
static int secp256k1_ecdsa_sig_verify(const secp256k1_ecdsa_sig_t *sig, const secp256k1_ge_t *pubkey, const secp256k1_scalar_t *message);
static int secp256k1_ecdsa_sig_sign(secp256k1_ecdsa_sig_t *sig, const secp256k1_scalar_t *seckey, const secp256k1_scalar_t *message, const secp256k1_scalar_t *nonce, int *recid);
static int secp256k1_ecdsa_sig_recover(const secp256k1_ecdsa_sig_t *sig, secp256k1_ge_t *pubkey, const secp256k1_scalar_t *message, int recid);
static void secp256k1_ecdsa_sig_set_rs(secp256k1_ecdsa_sig_t *sig, const secp256k1_scalar_t *r, const secp256k1_scalar_t *s);
#endif

42
src/ecdsa_impl.h
View file

@ -98,32 +98,33 @@ static int secp256k1_ecdsa_sig_verify(const secp256k1_ecdsa_sig_t *sig, const se
secp256k1_fe_t xr;
secp256k1_fe_set_b32(&xr, c);
// We now have the recomputed R point in pr, and its claimed x coordinate (modulo n)
// in xr. Naively, we would extract the x coordinate from pr (requiring a inversion modulo p),
// compute the remainder modulo n, and compare it to xr. However:
//
// xr == X(pr) mod n
// <=> exists h. (xr + h * n < p && xr + h * n == X(pr))
// [Since 2 * n > p, h can only be 0 or 1]
// <=> (xr == X(pr)) || (xr + n < p && xr + n == X(pr))
// [In Jacobian coordinates, X(pr) is pr.x / pr.z^2 mod p]
// <=> (xr == pr.x / pr.z^2 mod p) || (xr + n < p && xr + n == pr.x / pr.z^2 mod p)
// [Multiplying both sides of the equations by pr.z^2 mod p]
// <=> (xr * pr.z^2 mod p == pr.x) || (xr + n < p && (xr + n) * pr.z^2 mod p == pr.x)
//
// Thus, we can avoid the inversion, but we have to check both cases separately.
// secp256k1_gej_eq_x implements the (xr * pr.z^2 mod p == pr.x) test.
/** We now have the recomputed R point in pr, and its claimed x coordinate (modulo n)
* in xr. Naively, we would extract the x coordinate from pr (requiring a inversion modulo p),
* compute the remainder modulo n, and compare it to xr. However:
*
* xr == X(pr) mod n
* <=> exists h. (xr + h * n < p && xr + h * n == X(pr))
* [Since 2 * n > p, h can only be 0 or 1]
* <=> (xr == X(pr)) || (xr + n < p && xr + n == X(pr))
* [In Jacobian coordinates, X(pr) is pr.x / pr.z^2 mod p]
* <=> (xr == pr.x / pr.z^2 mod p) || (xr + n < p && xr + n == pr.x / pr.z^2 mod p)
* [Multiplying both sides of the equations by pr.z^2 mod p]
* <=> (xr * pr.z^2 mod p == pr.x) || (xr + n < p && (xr + n) * pr.z^2 mod p == pr.x)
*
* Thus, we can avoid the inversion, but we have to check both cases separately.
* secp256k1_gej_eq_x implements the (xr * pr.z^2 mod p == pr.x) test.
*/
if (secp256k1_gej_eq_x_var(&xr, &pr)) {
// xr.x == xr * xr.z^2 mod p, so the signature is valid.
/* xr.x == xr * xr.z^2 mod p, so the signature is valid. */
return 1;
}
if (secp256k1_fe_cmp_var(&xr, &secp256k1_ecdsa_const_p_minus_order) >= 0) {
// xr + p >= n, so we can skip testing the second case.
/* xr + p >= n, so we can skip testing the second case. */
return 0;
}
secp256k1_fe_add(&xr, &secp256k1_ecdsa_const_order_as_fe);
if (secp256k1_gej_eq_x_var(&xr, &pr)) {
// (xr + n) * pr.z^2 mod p == pr.x, so the signature is valid.
/* (xr + n) * pr.z^2 mod p == pr.x, so the signature is valid. */
return 1;
}
return 0;
@ -195,9 +196,4 @@ static int secp256k1_ecdsa_sig_sign(secp256k1_ecdsa_sig_t *sig, const secp256k1_
return 1;
}
static void secp256k1_ecdsa_sig_set_rs(secp256k1_ecdsa_sig_t *sig, const secp256k1_scalar_t *r, const secp256k1_scalar_t *s) {
sig->r = *r;
sig->s = *s;
}
#endif

2
src/field.h
View file

@ -102,7 +102,7 @@ static void secp256k1_fe_inv_var(secp256k1_fe_t *r, const secp256k1_fe_t *a);
/** Calculate the (modular) inverses of a batch of field elements. Requires the inputs' magnitudes to be
* at most 8. The output magnitudes are 1 (but not guaranteed to be normalized). The inputs and
* outputs must not overlap in memory. */
static void secp256k1_fe_inv_all_var(size_t len, secp256k1_fe_t r[len], const secp256k1_fe_t a[len]);
static void secp256k1_fe_inv_all_var(size_t len, secp256k1_fe_t *r, const secp256k1_fe_t *a);
/** Convert a field element to a hexadecimal string. */
static void secp256k1_fe_get_hex(char *r, int *rlen, const secp256k1_fe_t *a);

4
src/field_impl.h
View file

@ -40,7 +40,7 @@ static void secp256k1_fe_get_hex(char *r, int *rlen, const secp256k1_fe_t *a) {
}
static int secp256k1_fe_set_hex(secp256k1_fe_t *r, const char *a, int alen) {
unsigned char tmp[32] = {};
unsigned char tmp[32] = {0};
static const int cvt[256] = {0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
@ -227,7 +227,7 @@ static void secp256k1_fe_inv_var(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
#endif
}
static void secp256k1_fe_inv_all_var(size_t len, secp256k1_fe_t r[len], const secp256k1_fe_t a[len]) {
static void secp256k1_fe_inv_all_var(size_t len, secp256k1_fe_t *r, const secp256k1_fe_t *a) {
if (len < 1)
return;

2
src/group.h
View file

@ -50,7 +50,7 @@ static void secp256k1_ge_get_hex(char *r, int *rlen, const secp256k1_ge_t *a);
static void secp256k1_ge_set_gej(secp256k1_ge_t *r, secp256k1_gej_t *a);
/** Set a batch of group elements equal to the inputs given in jacobian coordinates */
static void secp256k1_ge_set_all_gej_var(size_t len, secp256k1_ge_t r[len], const secp256k1_gej_t a[len]);
static void secp256k1_ge_set_all_gej_var(size_t len, secp256k1_ge_t *r, const secp256k1_gej_t *a);
/** Set a group element (jacobian) equal to the point at infinity. */

9
src/group_impl.h
View file

@ -93,7 +93,7 @@ static void secp256k1_ge_set_gej_var(secp256k1_ge_t *r, secp256k1_gej_t *a) {
r->y = a->y;
}
static void secp256k1_ge_set_all_gej_var(size_t len, secp256k1_ge_t r[len], const secp256k1_gej_t a[len]) {
static void secp256k1_ge_set_all_gej_var(size_t len, secp256k1_ge_t *r, const secp256k1_gej_t *a) {
size_t count = 0;
secp256k1_fe_t *az = checked_malloc(sizeof(secp256k1_fe_t) * len);
for (size_t i=0; i<len; i++) {
@ -220,9 +220,10 @@ static int secp256k1_ge_is_valid_var(const secp256k1_ge_t *a) {
}
static void secp256k1_gej_double_var(secp256k1_gej_t *r, const secp256k1_gej_t *a) {
// For secp256k1, 2Q is infinity if and only if Q is infinity. This is because if 2Q = infinity,
// Q must equal -Q, or that Q.y == -(Q.y), or Q.y is 0. For a point on y^2 = x^3 + 7 to have
// y=0, x^3 must be -7 mod p. However, -7 has no cube root mod p.
/** For secp256k1, 2Q is infinity if and only if Q is infinity. This is because if 2Q = infinity,
* Q must equal -Q, or that Q.y == -(Q.y), or Q.y is 0. For a point on y^2 = x^3 + 7 to have
* y=0, x^3 must be -7 mod p. However, -7 has no cube root mod p.
*/
r->infinity = a->infinity;
if (r->infinity) {
return;

6
src/hash_impl.h
View file

@ -128,7 +128,7 @@ static void secp256k1_sha256_write(secp256k1_sha256_t *hash, const unsigned char
const unsigned char* end = data + len;
size_t bufsize = hash->bytes % 64;
if (bufsize && bufsize + len >= 64) {
// Fill the buffer, and process it.
/* Fill the buffer, and process it. */
memcpy(hash->buf + bufsize, data, 64 - bufsize);
hash->bytes += 64 - bufsize;
data += 64 - bufsize;
@ -136,13 +136,13 @@ static void secp256k1_sha256_write(secp256k1_sha256_t *hash, const unsigned char
bufsize = 0;
}
while (end >= data + 64) {
// Process full chunks directly from the source.
/* Process full chunks directly from the source. */
secp256k1_sha256_transform(hash->s, data);
hash->bytes += 64;
data += 64;
}
if (end > data) {
// Fill the buffer with what remains.
/* Fill the buffer with what remains. */
memcpy(hash->buf + bufsize, data, end - data);
hash->bytes += end - data;
}

2
src/util.h
View file

@ -61,7 +61,7 @@
#define VERIFY_CHECK(cond) do { (void)(cond); } while(0)
#endif
static inline void *checked_malloc(size_t size) {
static SECP256K1_INLINE void *checked_malloc(size_t size) {
void *ret = malloc(size);
CHECK(ret != NULL);
return ret;