barrett_test.go

package ed448

import . "gopkg.in/check.v1"

func (s *Ed448Suite) Test_BarrettDeserializeAndReduce(c *C) {
	serialized := [64]byte{
		0x1d, 0x07, 0xfb, 0x9c, 0x79, 0x80, 0x5f, 0x01,
		0x52, 0xc9, 0x09, 0xbf, 0x4c, 0xdb, 0xb1, 0x31,
		0x95, 0x31, 0x78, 0xc9, 0xff, 0x4f, 0x34, 0xc7,
		0x77, 0x7c, 0x89, 0x4e, 0xe0, 0x8f, 0xca, 0x9f,
		0x59, 0x8a, 0x00, 0x37, 0x78, 0x2c, 0xa6, 0x9b,
		0xbe, 0x5b, 0xb4, 0x1d, 0x25, 0x6a, 0x83, 0x32,
		0x7c, 0xd0, 0xc0, 0x3d, 0xa5, 0x26, 0xf8, 0x77,
		0xd3, 0x74, 0x3e, 0x3b, 0x7b, 0x21, 0x70, 0x01,
	}

	result := scalar{}

	barrettDeserializeAndReduce(result[:], serialized[:], &curvePrimeOrder)

	c.Assert(result, DeepEquals, scalar{
		0x3e3f0106, 0x109e3fb3, 0x2334dede, 0x44759a6a,
		0x4f184169, 0x5052b779, 0xe27da003, 0x8a15ee89,
		0x39f344af, 0x9ba62c78, 0x1db45bbe, 0x32836a25,
		0x3dc0d07c, 0x37f826a5,
	})
}

func (s *Ed448Suite) Test_BarrettDeserialize(c *C) {
	//This is not reduced
	serialized := [fieldBytes]byte{
		0xfe, 0x58, 0x5b, 0x65, 0x91, 0x38, 0x65, 0x18,
		0x9d, 0xfe, 0x90, 0x33, 0x48, 0xbe, 0xac, 0x47,
		0xee, 0x65, 0x09, 0x28, 0xde, 0xe5, 0x04, 0x05,
		0xd9, 0xa6, 0xd4, 0x43, 0x54, 0x18, 0xa2, 0xfd,
		0xf1, 0xf2, 0x64, 0xee, 0xae, 0xae, 0xc5, 0xe7,
		0x68, 0xa4, 0x2e, 0xde, 0x76, 0x60, 0xe6, 0x4a,
		0x51, 0x12, 0xb1, 0x35, 0x3d, 0xac, 0x04, 0xc8,
	}

	result := scalar{}

	reduced := barrettDeserialize(result[:], serialized[:], &curvePrimeOrder)
	c.Assert(reduced, Equals, false)

	c.Assert(result, DeepEquals, scalar{
		0x655b58fe, 0x18653891, 0x3390fe9d, 0x47acbe48,
		0x280965ee, 0x0504e5de, 0x43d4a6d9, 0xfda21854,
		0xee64f2f1, 0xe7c5aeae, 0xde2ea468, 0x4ae66076,
		0x35b11251, 0xc804ac3d,
	})

	//This is already reduced prime-order
	serialized = [fieldBytes]byte{
		0x25, 0x8a, 0x52, 0x63, 0xd9, 0xf0, 0xfa, 0xad,
		0x9d, 0x50, 0x40, 0x8a, 0xf0, 0x76, 0x66, 0xe3,
		0x3d, 0xc2, 0x86, 0x1b, 0x01, 0x54, 0x18, 0xb8,
		0x1b, 0x3b, 0x76, 0xcd, 0x55, 0x18, 0xa2, 0xfd,
		0xf1, 0xf2, 0x64, 0xee, 0xae, 0xae, 0xc5, 0xe7,
		0x68, 0xa4, 0x2e, 0xde, 0x76, 0x60, 0xe6, 0x4a,
		0x51, 0x12, 0xb1, 0x35, 0x3d, 0xac, 0x04, 0x08,
	}

	reduced = barrettDeserialize(result[:], serialized[:], &curvePrimeOrder)
	c.Assert(reduced, Equals, true)

	c.Assert(result, DeepEquals, scalar{
		0x63528a25, 0xadfaf0d9, 0x8a40509d, 0xe36676f0,
		0x1b86c23d, 0xb8185401, 0xcd763b1b, 0xfda21855,
		0xee64f2f1, 0xe7c5aeae, 0xde2ea468, 0x4ae66076,
		0x35b11251, 0x0804ac3d,
	})
}

func (s *Ed448Suite) Test_BarrettNegate(c *C) {
	n := scalar{
		0x6c226d73, 0x70edcfc3, 0x44156c47, 0x84f4695,
		0xe72606ac, 0x9d0ce5e5, 0xed96d3ba, 0x9ff3fa11,
		0x4a15c383, 0xca38a0af, 0xead789b3, 0xb96613ba,
		0x48ba4461, 0x34eb2031,
	}

	notN := scalar{
		0x3f35d780, 0xb28af2cf, 0x49b0230d, 0x191d7bdd,
		0xc7b02fe4, 0x2741f563, 0x8f33502f, 0x600c05ed,
		0xb5ea3c7c, 0x35c75f50, 0x1528764c, 0x4699ec45,
		0xb745bb9e, 0x0b14dfce,
	}

	barrettNegate(n[:], &curvePrimeOrder)

	c.Assert(n, DeepEquals, notN)
}

func (s *Ed448Suite) Test_BarrettMac(c *C) {
	accum := scalar{
		0xc7a99dbd, 0xb92054cc, 0x79b10a3e, 0x38afe6b9,
		0x859aa259, 0x007e0791, 0x91958009, 0x1ed45cd0,
		0xbbfa381b, 0x1f427b27, 0xb194eb5c, 0x501789df,
		0x1616d689, 0x17db93b0,
	}

	x := scalar{
		0x3f35d780, 0xb28af2cf, 0x49b0230d, 0x191d7bdd,
		0xc7b02fe4, 0x2741f563, 0x8f33502f, 0x600c05ed,
		0xb5ea3c7c, 0x35c75f50, 0x1528764c, 0x4699ec45,
		0xb745bb9e, 0x0b14dfce,
	}

	y := scalar{
		0x2efd441f, 0xa8ca47de, 0x88454c7c, 0x5a017e1a,
		0xfb3701a9, 0xe0b9be0d, 0xf72947eb, 0x235c0b74,
		0x39fdaa66, 0x80783803, 0x1306b28f, 0x02cffb4e,
		0x3a114311, 0x22b8f8d1,
	}

	expected := scalar{
		0x908c5c63, 0x21ab566a, 0x936bf39e, 0xa2c8ba5b,
		0xf885f518, 0xc1f2945d, 0x5cb06b4a, 0xe86d3f14,
		0xdd6bfcd0, 0x74fadd00, 0x4a750a8c, 0x8962c665,
		0x18163b75, 0x1de81b1f,
	}

	barrettMac(accum[:], x[:], y[:], &curvePrimeOrder)

	c.Assert(accum, DeepEquals, expected)
}