From 60cce0124f2fc3eddca03ed3950da9238247a612 Mon Sep 17 00:00:00 2001 From: Rob Austein Date: Sat, 3 Oct 2015 18:12:20 -0400 Subject: Use initializers for automatic variables of type fp_int because it's a bit more obvious when we've forgotten to do this than when we've forgotten to call fp_init() or memset(). Convert rsa.c to use the one-element-array idiom so we can get stop prefixing every bignum reference with "&". --- ecdsa.c | 92 +++++++++++++++++++++++++++++++++++++++-------------------------- 1 file changed, 56 insertions(+), 36 deletions(-) (limited to 'ecdsa.c') diff --git a/ecdsa.c b/ecdsa.c index 32855df..e2da87e 100644 --- a/ecdsa.c +++ b/ecdsa.c @@ -160,6 +160,17 @@ struct hal_ecdsa_key { const size_t hal_ecdsa_key_t_size = sizeof(struct hal_ecdsa_key); +/* + * Initializers. We want to be able to initialize automatic fp_int + * and ec_point_t variables to a sane value (less error prone), but + * picky compilers whine about the number of curly braces required. + * So we define macros which isolate that madness in one place, and + * use those macros everywhere. + */ + +#define INIT_FP_INT {{{0}}} +#define INIT_EC_POINT_T {{INIT_FP_INT}} + /* * Error handling. */ @@ -167,9 +178,9 @@ const size_t hal_ecdsa_key_t_size = sizeof(struct hal_ecdsa_key); #define lose(_code_) do { err = _code_; goto fail; } while (0) /* - * We can't (usefully) initialize fp_int variables at compile time, so - * instead we load all the curve parameters the first time anything - * asks for any of them. + * We can't (usefully) initialize fp_int variables to non-zero values + * at compile time, so instead we load all the curve parameters the + * first time anything asks for any of them. */ static const ecdsa_curve_t * const get_curve(const hal_ecdsa_curve_t curve) @@ -252,8 +263,7 @@ static inline void ff_add(const ecdsa_curve_t * const curve, const fp_int * const b, fp_int *c) { - fp_int t[2][1]; - memset(t, 0, sizeof(t)); + fp_int t[2][1] = {INIT_FP_INT}; fp_add(unconst_fp_int(a), unconst_fp_int(b), t[0]); fp_sub(t[0], unconst_fp_int(curve->q), t[1]); @@ -268,8 +278,7 @@ static inline void ff_sub(const ecdsa_curve_t * const curve, const fp_int * const b, fp_int *c) { - fp_int t[2][1]; - memset(t, 0, sizeof(t)); + fp_int t[2][1] = {INIT_FP_INT}; fp_sub(unconst_fp_int(a), unconst_fp_int(b), t[0]); fp_add(t[0], unconst_fp_int(curve->q), t[1]); @@ -393,8 +402,8 @@ static inline hal_error_t point_to_affine(ec_point_t *P, hal_error_t err = HAL_ERROR_IMPOSSIBLE; - fp_int t1[1]; fp_init(t1); - fp_int t2[1]; fp_init(t2); + fp_int t1[1] = INIT_FP_INT; + fp_int t2[1] = INIT_FP_INT; fp_int * const q = unconst_fp_int(curve->q); @@ -438,9 +447,12 @@ static inline void point_double(const ec_point_t * const P, const int was_infinite = point_is_infinite(P); - fp_int alpha[1], beta[1], gamma[1], delta[1], t1[1], t2[1]; - - fp_init(alpha); fp_init(beta); fp_init(gamma); fp_init(delta); fp_init(t1); fp_init(t2); + fp_int alpha[1] = INIT_FP_INT; + fp_int beta[1] = INIT_FP_INT; + fp_int gamma[1] = INIT_FP_INT; + fp_int delta[1] = INIT_FP_INT; + fp_int t1[1] = INIT_FP_INT; + fp_int t2[1] = INIT_FP_INT; ff_sqr (curve, P->z, delta); /* delta = Pz ** 2 */ ff_sqr (curve, P->y, gamma); /* gamma = Py ** 2 */ @@ -528,8 +540,7 @@ static inline void point_add(const ec_point_t * const P, const int P_was_infinite = point_is_infinite(P); - fp_int Qy_neg[1]; - fp_init(Qy_neg); + fp_int Qy_neg[1] = INIT_FP_INT; fp_sub(unconst_fp_int(curve->q), unconst_fp_int(Q->y), Qy_neg); const int result_is_infinite = fp_cmp(unconst_fp_int(P->y), Qy_neg) == FP_EQ && same_xz; fp_zero(Qy_neg); @@ -538,9 +549,14 @@ static inline void point_add(const ec_point_t * const P, * Main point addition algorithm. */ - fp_int Z1Z1[1], H[1], HH[1], I[1], J[1], r[1], V[1], t[1]; - - fp_init(Z1Z1), fp_init(H), fp_init(HH), fp_init(I), fp_init(J), fp_init(r), fp_init(V), fp_init(t); + fp_int Z1Z1[1] = INIT_FP_INT; + fp_int H[1] = INIT_FP_INT; + fp_int HH[1] = INIT_FP_INT; + fp_int I[1] = INIT_FP_INT; + fp_int J[1] = INIT_FP_INT; + fp_int r[1] = INIT_FP_INT; + fp_int V[1] = INIT_FP_INT; + fp_int t[1] = INIT_FP_INT; ff_sqr (curve, P->z, Z1Z1); /* Z1Z1 = Pz ** 2 */ @@ -618,7 +634,7 @@ static hal_error_t point_scalar_multiply(const fp_int * const k, */ ec_point_t P[1]; - memcpy(P, P_, sizeof(P)); + point_copy(P_, P); if ((err = point_to_montgomery(P, curve)) != HAL_OK) { memset(P, 0, sizeof(P)); @@ -631,8 +647,8 @@ static hal_error_t point_scalar_multiply(const fp_int * const k, * M[1] is where we accumulate the result. */ - ec_point_t M[2][1]; - memset(M, 0, sizeof(M)); + ec_point_t M[2][1] = {INIT_EC_POINT_T}; + point_set_infinite(M[0], curve); point_set_infinite(M[1], curve); @@ -779,8 +795,8 @@ static int point_is_on_curve(const ec_point_t * const P, { assert(P != NULL && curve != NULL); - fp_int t1[1]; fp_init(t1); - fp_int t2[1]; fp_init(t2); + fp_int t1[1] = INIT_FP_INT; + fp_int t2[1] = INIT_FP_INT; /* * Compute y**2 - x**3 + 3*x. @@ -1104,7 +1120,7 @@ hal_error_t hal_ecdsa_key_to_der(const hal_ecdsa_key_t * const key, const size_t Qy_len = fp_unsigned_bin_size(unconst_fp_int(key->Q->y)); assert(q_len >= d_len && q_len >= Qx_len && q_len >= Qy_len); - fp_int version[1]; + fp_int version[1] = INIT_FP_INT; fp_set(version, 1); hal_error_t err; @@ -1211,7 +1227,7 @@ hal_error_t hal_ecdsa_key_from_der(hal_ecdsa_key_t **key_, const uint8_t * const der_end = der + hlen + vlen; const uint8_t *d = der + hlen; const ecdsa_curve_t *curve = NULL; - fp_int version[1]; + fp_int version[1] = INIT_FP_INT; if ((err = hal_asn1_decode_integer(version, d, &hlen, vlen)) != HAL_OK) goto fail; @@ -1418,16 +1434,15 @@ hal_error_t hal_ecdsa_sign(const hal_ecdsa_key_t * const key, if (curve == NULL) return HAL_ERROR_IMPOSSIBLE; - fp_int k[1]; fp_init(k); - fp_int r[1]; fp_init(r); - fp_int s[1]; fp_init(s); - fp_int e[1]; fp_init(e); + fp_int k[1] = INIT_FP_INT; + fp_int r[1] = INIT_FP_INT; + fp_int s[1] = INIT_FP_INT; + fp_int e[1] = INIT_FP_INT; fp_int * const n = unconst_fp_int(curve->n); fp_int * const d = unconst_fp_int(key->d); - ec_point_t R[1]; - memset(R, 0, sizeof(R)); + ec_point_t R[1] = INIT_EC_POINT_T; hal_error_t err; @@ -1518,13 +1533,18 @@ hal_error_t hal_ecdsa_verify(const hal_ecdsa_key_t * const key, fp_int * const n = unconst_fp_int(curve->n); hal_error_t err; - fp_int r[1], s[1], e[1], w[1], u1[1], u2[1], v[1]; - ec_point_t u1G[1], u2Q[1], R[1]; - fp_init(w); fp_init(u1); fp_init(u2); fp_init(v); - memset(u1G, 0, sizeof(u1G)); - memset(u2Q, 0, sizeof(u2Q)); - memset(R, 0, sizeof(R)); + fp_int r[1] = INIT_FP_INT; + fp_int s[1] = INIT_FP_INT; + fp_int e[1] = INIT_FP_INT; + fp_int w[1] = INIT_FP_INT; + fp_int u1[1] = INIT_FP_INT; + fp_int u2[1] = INIT_FP_INT; + fp_int v[1] = INIT_FP_INT; + + ec_point_t u1G[1] = INIT_EC_POINT_T; + ec_point_t u2Q[1] = INIT_EC_POINT_T; + ec_point_t R[1] = INIT_EC_POINT_T; /* * Start by decoding the signature. -- cgit v1.2.3