i2pd/tests/test-elligator.cpp

#include <cassert>
#include <inttypes.h>
#include <string.h>

#include "Elligator.h"

const uint8_t key[32] =
{
	0x33, 0x95, 0x19, 0x64, 0x00, 0x3c, 0x94, 0x08, 0x78, 0x06, 0x3c, 0xcf, 0xd0, 0x34, 0x8a, 0xf4,
	0x21, 0x50, 0xca, 0x16, 0xd2, 0x64, 0x6f, 0x2c, 0x58, 0x56, 0xe8, 0x33, 0x83, 0x77, 0xd8, 0x80
};

const uint8_t encoded_key[32] =
{
	0x28, 0x20, 0xb6, 0xb2, 0x41, 0xe0, 0xf6, 0x8a, 0x6c, 0x4a, 0x7f, 0xee, 0x3d, 0x97, 0x82, 0x28,
	0xef, 0x3a, 0xe4, 0x55, 0x33, 0xcd, 0x41, 0x0a, 0xa9, 0x1a, 0x41, 0x53, 0x31, 0xd8, 0x61, 0x2d
};

const uint8_t encoded_key_high_y[32] =
{
	0x3c, 0xfb, 0x87, 0xc4, 0x6c, 0x0b, 0x45, 0x75, 0xca, 0x81, 0x75, 0xe0, 0xed, 0x1c, 0x0a, 0xe9,
	0xda, 0xe7, 0x9d, 0xb7, 0x8d, 0xf8, 0x69, 0x97, 0xc4, 0x84, 0x7b, 0x9f, 0x20, 0xb2, 0x77, 0x18
};

const uint8_t encoded1[32] =
{
	0xe7, 0x35, 0x07, 0xd3, 0x8b, 0xae, 0x63, 0x99, 0x2b, 0x3f, 0x57, 0xaa, 0xc4, 0x8c, 0x0a, 0xbc,
	0x14, 0x50, 0x95, 0x89, 0x28, 0x84, 0x57, 0x99, 0x5a, 0x2b, 0x4c, 0xa3, 0x49, 0x0a, 0xa2, 0x07
};

const uint8_t key1[32] =
{
	0x1e, 0x8a, 0xff, 0xfe, 0xd6, 0xbf, 0x53, 0xfe, 0x27, 0x1a, 0xd5, 0x72, 0x47, 0x32, 0x62, 0xde,
	0xd8, 0xfa, 0xec, 0x68, 0xe5, 0xe6, 0x7e, 0xf4, 0x5e, 0xbb, 0x82, 0xee, 0xba, 0x52, 0x60, 0x4f
};

const uint8_t encoded2[32] =
{
	0x95, 0xa1, 0x60, 0x19, 0x04, 0x1d, 0xbe, 0xfe, 0xd9, 0x83, 0x20, 0x48, 0xed, 0xe1, 0x19, 0x28,
	0xd9, 0x03, 0x65, 0xf2, 0x4a, 0x38, 0xaa, 0x7a, 0xef, 0x1b, 0x97, 0xe2, 0x39, 0x54, 0x10, 0x1b
};

const uint8_t key2[32] =
{
	0x79, 0x4f, 0x05, 0xba, 0x3e, 0x3a, 0x72, 0x95, 0x80, 0x22, 0x46, 0x8c, 0x88, 0x98, 0x1e, 0x0b,
	0xe5, 0x78, 0x2b, 0xe1, 0xe1, 0x14, 0x5c, 0xe2, 0xc3, 0xc6, 0xfd, 0xe1, 0x6d, 0xed, 0x53, 0x63
};

const uint8_t encoded3[32] =
{
	0xf6, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x3f
};

const uint8_t key3[32] =
{
	0x9c, 0xdb, 0x52, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55,
	0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55
};

const uint8_t failed_key[32] =
{
    0xe6, 0xf6, 0x6f, 0xdf, 0x6e, 0x23, 0x0c, 0x60, 0x3c, 0x5e, 0x6e, 0x59, 0xa2, 0x54, 0xea, 0x14,
	0x76, 0xa1, 0x3e, 0xb9, 0x51, 0x1b, 0x95, 0x49, 0x84, 0x67, 0x81, 0xe1, 0x2e, 0x52, 0x23, 0x0a
};

int main ()
{
	uint8_t buf[32];
	i2p::crypto::Elligator2 el;
	// encoding tests
	el.Encode (key, buf, false, false);
	assert(memcmp (buf, encoded_key, 32) == 0);
	el.Encode (key, buf, true, false); // with highY
	assert(memcmp (buf, encoded_key_high_y, 32) == 0);
	// decoding tests
	el.Decode (encoded1, buf);
	assert(memcmp (buf, key1, 32) == 0);
	el.Decode (encoded2, buf);
	assert(memcmp (buf, key2, 32) == 0);
	el.Decode (encoded3, buf);
	assert(memcmp (buf, key3, 32) == 0);
    // encoding fails
    assert (!el.Encode (failed_key, buf));
}