I want to know the sgx_ecc256_compute_shared_dhkey() which Elliptical Curve use?

[peng__yao]

Hi

I try to use Openssl to change key with SGX use ecdh

when use sgx_ecc256_compute_shared_dhkey() to generate share-key,

but  the share-key not correct.

so i want to know which Elliptical Curve used in SGX.

 or are there any mistakes?

Thanks a lot for anyone's help!

[you_w_]

Hi peng:

Before we call " sgx_ecc256_compute_shared_dhkey()", we need to call "sgx_ecc256_open_context()", the ecc curve is set in this method, you can find 

/* construct a curve p-256 */

EC_GROUP* ec_group = EC_GROUP_new_by_curve_name(NID_X9_62_prime256v1);

in that method.

Regards

you

[Yan__Yudao]

I find them in openssl code:

static const struct {

EC_CURVE_DATA h;

unsigned char data[20 + 32 * 6];

} _EC_X9_62_PRIME_256V1 = {

{

NID_X9_62_prime_field, 20, 32, 1

},

{

/* seed */

0xC4, 0x9D, 0x36, 0x08, 0x86, 0xE7, 0x04, 0x93, 0x6A, 0x66, 0x78, 0xE1,

0x13, 0x9D, 0x26, 0xB7, 0x81, 0x9F, 0x7E, 0x90,

/* p */

0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00,

0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF,

0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,

/* a */

0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00,

0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF,

0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFC,

/* b */

0x5A, 0xC6, 0x35, 0xD8, 0xAA, 0x3A, 0x93, 0xE7, 0xB3, 0xEB, 0xBD, 0x55,

0x76, 0x98, 0x86, 0xBC, 0x65, 0x1D, 0x06, 0xB0, 0xCC, 0x53, 0xB0, 0xF6,

0x3B, 0xCE, 0x3C, 0x3E, 0x27, 0xD2, 0x60, 0x4B,

/* x */

0x6B, 0x17, 0xD1, 0xF2, 0xE1, 0x2C, 0x42, 0x47, 0xF8, 0xBC, 0xE6, 0xE5,

0x63, 0xA4, 0x40, 0xF2, 0x77, 0x03, 0x7D, 0x81, 0x2D, 0xEB, 0x33, 0xA0,

0xF4, 0xA1, 0x39, 0x45, 0xD8, 0x98, 0xC2, 0x96,

/* y */

0x4f, 0xe3, 0x42, 0xe2, 0xfe, 0x1a, 0x7f, 0x9b, 0x8e, 0xe7, 0xeb, 0x4a,

0x7c, 0x0f, 0x9e, 0x16, 0x2b, 0xce, 0x33, 0x57, 0x6b, 0x31, 0x5e, 0xce,

0xcb, 0xb6, 0x40, 0x68, 0x37, 0xbf, 0x51, 0xf5,

/* order */

0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF,

0xFF, 0xFF, 0xFF, 0xFF, 0xBC, 0xE6, 0xFA, 0xAD, 0xA7, 0x17, 0x9E, 0x84,

0xF3, 0xB9, 0xCA, 0xC2, 0xFC, 0x63, 0x25, 0x51

}

};