#include <openssl/err.h>
#include "ec_lcl.h"
-typedef __uint128_t uint128_t; /* nonstandard; implemented by gcc on 64-bit platforms */
+#if defined(__GNUC__) && (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1))
+ /* even with gcc, the typedef won't work for 32-bit platforms */
+ typedef __uint128_t uint128_t; /* nonstandard; implemented by gcc on 64-bit platforms */
+#else
+ #error "Need GCC 3.1 or later to define type uint128_t"
+#endif
typedef uint8_t u8;
-static const u8 nistp224_curve_params[5*28] = {
- 0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF, /* p */
- 0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0x00,0x00,0x00,0x00,
- 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,
- 0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF, /* a */
- 0xFF,0xFF,0xFF,0xFF,0xFF,0xFE,0xFF,0xFF,0xFF,0xFF,
- 0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFE,
- 0xB4,0x05,0x0A,0x85,0x0C,0x04,0xB3,0xAB,0xF5,0x41, /* b */
- 0x32,0x56,0x50,0x44,0xB0,0xB7,0xD7,0xBF,0xD8,0xBA,
- 0x27,0x0B,0x39,0x43,0x23,0x55,0xFF,0xB4,
- 0xB7,0x0E,0x0C,0xBD,0x6B,0xB4,0xBF,0x7F,0x32,0x13, /* x */
- 0x90,0xB9,0x4A,0x03,0xC1,0xD3,0x56,0xC2,0x11,0x22,
- 0x34,0x32,0x80,0xD6,0x11,0x5C,0x1D,0x21,
- 0xbd,0x37,0x63,0x88,0xb5,0xf7,0x23,0xfb,0x4c,0x22, /* y */
- 0xdf,0xe6,0xcd,0x43,0x75,0xa0,0x5a,0x07,0x47,0x64,
- 0x44,0xd5,0x81,0x99,0x85,0x00,0x7e,0x34
-};
/******************************************************************************/
/* INTERNAL REPRESENTATION OF FIELD ELEMENTS
typedef uint64_t fslice;
-/* Field element size (and group order size), in bytes: 28*8 = 224 */
-static const unsigned fElemSize = 28;
+/* Field element represented as a byte arrary.
+ * 28*8 = 224 bits is also the group order size for the elliptic curve. */
+typedef u8 felem_bytearray[28];
+
+static const felem_bytearray nistp224_curve_params[5] = {
+ {0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF, /* p */
+ 0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0x00,0x00,0x00,0x00,
+ 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01},
+ {0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF, /* a */
+ 0xFF,0xFF,0xFF,0xFF,0xFF,0xFE,0xFF,0xFF,0xFF,0xFF,
+ 0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFE},
+ {0xB4,0x05,0x0A,0x85,0x0C,0x04,0xB3,0xAB,0xF5,0x41, /* b */
+ 0x32,0x56,0x50,0x44,0xB0,0xB7,0xD7,0xBF,0xD8,0xBA,
+ 0x27,0x0B,0x39,0x43,0x23,0x55,0xFF,0xB4},
+ {0xB7,0x0E,0x0C,0xBD,0x6B,0xB4,0xBF,0x7F,0x32,0x13, /* x */
+ 0x90,0xB9,0x4A,0x03,0xC1,0xD3,0x56,0xC2,0x11,0x22,
+ 0x34,0x32,0x80,0xD6,0x11,0x5C,0x1D,0x21},
+ {0xbd,0x37,0x63,0x88,0xb5,0xf7,0x23,0xfb,0x4c,0x22, /* y */
+ 0xdf,0xe6,0xcd,0x43,0x75,0xa0,0x5a,0x07,0x47,0x64,
+ 0x44,0xd5,0x81,0x99,0x85,0x00,0x7e,0x34}
+};
/* Precomputed multiples of the standard generator
* b_0*G + b_1*2^56*G + b_2*2^112*G + b_3*2^168*G for
/* From OpenSSL BIGNUM to internal representation */
static int BN_to_felem(fslice out[4], const BIGNUM *bn)
{
- u8 b_in[fElemSize];
- u8 b_out[fElemSize];
+ felem_bytearray b_in;
+ felem_bytearray b_out;
unsigned num_bytes;
/* BN_bn2bin eats leading zeroes */
- memset(b_out, 0, fElemSize);
+ memset(b_out, 0, sizeof b_out);
num_bytes = BN_num_bytes(bn);
- if (num_bytes > fElemSize)
+ if (num_bytes > sizeof b_out)
{
ECerr(EC_F_BN_TO_FELEM, EC_R_BIGNUM_OUT_OF_RANGE);
return 0;
/* From internal representation to OpenSSL BIGNUM */
static BIGNUM *felem_to_BN(BIGNUM *out, const fslice in[4])
{
- u8 b_in[fElemSize], b_out[fElemSize];
+ felem_bytearray b_in, b_out;
felem_to_bin28(b_in, in);
- flip_endian(b_out, b_in, fElemSize);
- return BN_bin2bn(b_out, fElemSize, out);
+ flip_endian(b_out, b_in, sizeof b_out);
+ return BN_bin2bn(b_out, sizeof b_out, out);
}
/******************************************************************************/
* of the generator, using certain (large) precomputed multiples in g_pre_comp.
* Output point (X, Y, Z) is stored in x_out, y_out, z_out */
static void batch_mul(fslice x_out[4], fslice y_out[4], fslice z_out[4],
- const u8 scalars[][fElemSize], const unsigned num_points, const u8 *g_scalar,
+ const felem_bytearray scalars[], const unsigned num_points, const u8 *g_scalar,
const fslice pre_comp[][16][3][4], const fslice g_pre_comp[16][3][4])
{
unsigned i, j, num;
if (((curve_p = BN_CTX_get(ctx)) == NULL) ||
((curve_a = BN_CTX_get(ctx)) == NULL) ||
((curve_b = BN_CTX_get(ctx)) == NULL)) goto err;
- BN_bin2bn(nistp224_curve_params, fElemSize, curve_p);
- BN_bin2bn(nistp224_curve_params + 28, fElemSize, curve_a);
- BN_bin2bn(nistp224_curve_params + 56, fElemSize, curve_b);
+ BN_bin2bn(nistp224_curve_params[0], sizeof(felem_bytearray), curve_p);
+ BN_bin2bn(nistp224_curve_params[1], sizeof(felem_bytearray), curve_a);
+ BN_bin2bn(nistp224_curve_params[2], sizeof(felem_bytearray), curve_b);
if ((BN_cmp(curve_p, p)) || (BN_cmp(curve_a, a)) ||
(BN_cmp(curve_b, b)))
{
int i, j;
BN_CTX *new_ctx = NULL;
BIGNUM *x, *y, *z, *tmp_scalar;
- u8 g_secret[fElemSize];
- u8 (*secrets)[fElemSize] = NULL;
+ felem_bytearray g_secret;
+ felem_bytearray *secrets = NULL;
fslice (*pre_comp)[16][3][4] = NULL;
- u8 tmp[fElemSize];
+ felem_bytearray tmp;
unsigned num_bytes;
int have_pre_comp = 0;
size_t num_points = num;
* treat the generator as a random point */
num_points = num_points + 1;
}
- secrets = OPENSSL_malloc(num_points * fElemSize);
+ secrets = OPENSSL_malloc(num_points * sizeof(felem_bytearray));
pre_comp = OPENSSL_malloc(num_points * 16 * 3 * 4 * sizeof(fslice));
if ((num_points) && ((secrets == NULL) || (pre_comp == NULL)))
/* we treat NULL scalars as 0, and NULL points as points at infinity,
* i.e., they contribute nothing to the linear combination */
- memset(secrets, 0, num_points * fElemSize);
+ memset(secrets, 0, num_points * sizeof(felem_bytearray));
memset(pre_comp, 0, num_points * 16 * 3 * 4 * sizeof(fslice));
for (i = 0; i < num_points; ++i)
{
{
num_bytes = BN_num_bytes(p_scalar);
/* reduce scalar to 0 <= scalar < 2^224 */
- if ((num_bytes > fElemSize) || (BN_is_negative(p_scalar)))
+ if ((num_bytes > sizeof(felem_bytearray)) || (BN_is_negative(p_scalar)))
{
/* this is an unusual input, and we don't guarantee
* constant-timeness */
/* the scalar for the generator */
if ((scalar != NULL) && (have_pre_comp))
{
- memset(g_secret, 0, fElemSize);
+ memset(g_secret, 0, sizeof g_secret);
num_bytes = BN_num_bytes(scalar);
/* reduce scalar to 0 <= scalar < 2^224 */
- if ((num_bytes > fElemSize) || (BN_is_negative(scalar)))
+ if ((num_bytes > sizeof(felem_bytearray)) || (BN_is_negative(scalar)))
{
/* this is an unusual input, and we don't guarantee
* constant-timeness */
flip_endian(g_secret, tmp, num_bytes);
/* do the multiplication with generator precomputation*/
batch_mul(x_out, y_out, z_out,
- (const u8 (*)[fElemSize]) secrets, num_points,
+ (const felem_bytearray (*)) secrets, num_points,
g_secret, (const fslice (*)[16][3][4]) pre_comp,
(const fslice (*)[3][4]) g_pre_comp);
}
else
/* do the multiplication without generator precomputation */
batch_mul(x_out, y_out, z_out,
- (const u8 (*)[fElemSize]) secrets, num_points,
+ (const felem_bytearray (*)) secrets, num_points,
NULL, (const fslice (*)[16][3][4]) pre_comp, NULL);
/* reduce the output to its unique minimal representation */
felem_contract(x_in, x_out);
generator = EC_POINT_new(group);
if (generator == NULL)
goto err;
- BN_bin2bn(nistp224_curve_params + 84, fElemSize, x);
- BN_bin2bn(nistp224_curve_params + 112, fElemSize, y);
+ BN_bin2bn(nistp224_curve_params[3], sizeof (felem_bytearray), x);
+ BN_bin2bn(nistp224_curve_params[4], sizeof (felem_bytearray), y);
if (!EC_POINT_set_affine_coordinates_GFp(group, generator, x, y, ctx))
goto err;
if ((pre = nistp224_pre_comp_new()) == NULL)
else
return 0;
}
+
+#else
+static void *dummy=&dummy;
#endif