diff options
Diffstat (limited to 'crypto/ec/ecp_nistp521.c')
-rw-r--r-- | crypto/ec/ecp_nistp521.c | 111 |
1 files changed, 56 insertions, 55 deletions
diff --git a/crypto/ec/ecp_nistp521.c b/crypto/ec/ecp_nistp521.c index c1ef3fedac..cc7634512d 100644 --- a/crypto/ec/ecp_nistp521.c +++ b/crypto/ec/ecp_nistp521.c @@ -414,15 +414,16 @@ static void felem_square(largefelem out, const felem in) felem_scalar(inx2, in, 2); felem_scalar(inx4, in, 4); - /*- - * We have many cases were we want to do - * in[x] * in[y] + - * in[y] * in[x] - * This is obviously just - * 2 * in[x] * in[y] - * However, rather than do the doubling on the 128 bit result, we - * double one of the inputs to the multiplication by reading from - * |inx2| */ + /*- + * We have many cases were we want to do + * in[x] * in[y] + + * in[y] * in[x] + * This is obviously just + * 2 * in[x] * in[y] + * However, rather than do the doubling on the 128 bit result, we + * double one of the inputs to the multiplication by reading from + * |inx2| + */ out[0] = ((uint128_t) in[0]) * in[0]; out[1] = ((uint128_t) in[0]) * inx2[1]; @@ -610,10 +611,10 @@ static void felem_reduce(felem out, const largefelem in) out[1] += ((limb) in[0]) >> 58; out[1] += (((limb) (in[0] >> 64)) & bottom52bits) << 6; - /*- - * out[1] < 2^58 + 2^6 + 2^58 - * = 2^59 + 2^6 - */ + /*- + * out[1] < 2^58 + 2^6 + 2^58 + * = 2^59 + 2^6 + */ out[2] += ((limb) (in[0] >> 64)) >> 52; out[2] += ((limb) in[1]) >> 58; @@ -642,10 +643,10 @@ static void felem_reduce(felem out, const largefelem in) out[8] += ((limb) in[7]) >> 58; out[8] += (((limb) (in[7] >> 64)) & bottom52bits) << 6; - /*- - * out[x > 1] < 2^58 + 2^6 + 2^58 + 2^12 - * < 2^59 + 2^13 - */ + /*- + * out[x > 1] < 2^58 + 2^6 + 2^58 + 2^12 + * < 2^59 + 2^13 + */ overflow1 = ((limb) (in[7] >> 64)) >> 52; overflow1 += ((limb) in[8]) >> 58; @@ -660,11 +661,11 @@ static void felem_reduce(felem out, const largefelem in) out[1] += out[0] >> 58; out[0] &= bottom58bits; - /*- - * out[0] < 2^58 - * out[1] < 2^59 + 2^6 + 2^13 + 2^2 - * < 2^59 + 2^14 - */ + /*- + * out[0] < 2^58 + * out[1] < 2^59 + 2^6 + 2^13 + 2^2 + * < 2^59 + 2^14 + */ } static void felem_square_reduce(felem out, const felem in) @@ -1055,13 +1056,13 @@ point_double(felem x_out, felem y_out, felem z_out, felem_scalar64(ftmp2, 3); /* ftmp2[i] < 3*2^60 + 3*2^15 */ felem_mul(tmp, ftmp, ftmp2); - /*- - * tmp[i] < 17(3*2^121 + 3*2^76) - * = 61*2^121 + 61*2^76 - * < 64*2^121 + 64*2^76 - * = 2^127 + 2^82 - * < 2^128 - */ + /*- + * tmp[i] < 17(3*2^121 + 3*2^76) + * = 61*2^121 + 61*2^76 + * < 64*2^121 + 64*2^76 + * = 2^127 + 2^82 + * < 2^128 + */ felem_reduce(alpha, tmp); /* x' = alpha^2 - 8*beta */ @@ -1096,30 +1097,30 @@ point_double(felem x_out, felem y_out, felem z_out, felem_diff64(beta, x_out); /* beta[i] < 2^61 + 2^60 + 2^16 */ felem_mul(tmp, alpha, beta); - /*- - * tmp[i] < 17*((2^59 + 2^14)(2^61 + 2^60 + 2^16)) - * = 17*(2^120 + 2^75 + 2^119 + 2^74 + 2^75 + 2^30) - * = 17*(2^120 + 2^119 + 2^76 + 2^74 + 2^30) - * < 2^128 - */ + /*- + * tmp[i] < 17*((2^59 + 2^14)(2^61 + 2^60 + 2^16)) + * = 17*(2^120 + 2^75 + 2^119 + 2^74 + 2^75 + 2^30) + * = 17*(2^120 + 2^119 + 2^76 + 2^74 + 2^30) + * < 2^128 + */ felem_square(tmp2, gamma); - /*- - * tmp2[i] < 17*(2^59 + 2^14)^2 - * = 17*(2^118 + 2^74 + 2^28) - */ + /*- + * tmp2[i] < 17*(2^59 + 2^14)^2 + * = 17*(2^118 + 2^74 + 2^28) + */ felem_scalar128(tmp2, 8); - /*- - * tmp2[i] < 8*17*(2^118 + 2^74 + 2^28) - * = 2^125 + 2^121 + 2^81 + 2^77 + 2^35 + 2^31 - * < 2^126 - */ + /*- + * tmp2[i] < 8*17*(2^118 + 2^74 + 2^28) + * = 2^125 + 2^121 + 2^81 + 2^77 + 2^35 + 2^31 + * < 2^126 + */ felem_diff128(tmp, tmp2); - /*- - * tmp[i] < 2^127 - 2^69 + 17(2^120 + 2^119 + 2^76 + 2^74 + 2^30) - * = 2^127 + 2^124 + 2^122 + 2^120 + 2^118 + 2^80 + 2^78 + 2^76 + - * 2^74 + 2^69 + 2^34 + 2^30 - * < 2^128 - */ + /*- + * tmp[i] < 2^127 - 2^69 + 17(2^120 + 2^119 + 2^76 + 2^74 + 2^30) + * = 2^127 + 2^124 + 2^122 + 2^120 + 2^118 + 2^80 + 2^78 + 2^76 + + * 2^74 + 2^69 + 2^34 + 2^30 + * < 2^128 + */ felem_reduce(y_out, tmp); } @@ -1281,11 +1282,11 @@ static void point_add(felem x3, felem y3, felem z3, felem_scalar128(tmp2, 2); /* tmp2[i] < 17*2^121 */ felem_diff128(tmp, tmp2); - /*- - * tmp[i] < 2^127 - 2^69 + 17*2^122 - * = 2^126 - 2^122 - 2^6 - 2^2 - 1 - * < 2^127 - */ + /*- + * tmp[i] < 2^127 - 2^69 + 17*2^122 + * = 2^126 - 2^122 - 2^6 - 2^2 - 1 + * < 2^127 + */ felem_reduce(y_out, tmp); copy_conditional(x_out, x2, z1_is_zero); |