package gf127 import ( "testing" "github.com/stretchr/testify/require" ) const maxUint64 = ^uint64(0) func TestAdd(t *testing.T) { var ( a = Random() b = Random() e = &GF127{a[0] ^ b[0], a[1] ^ b[1]} c = new(GF127) ) c.Add(a, b) require.Equal(t, e, c) } var testCasesMul = [][3]*GF127{ // (x+1)*(x^63+x^62+...+1) == x^64+1 {&GF127{3, 0}, &GF127{maxUint64, 0}, &GF127{1, 1}}, // x^126 * x^2 == x^128 == x^64 + x {&GF127{0, 1 << 62}, &GF127{4, 0}, &GF127{2, 1}}, // (x^64+x^63+1) * (x^64+x) == x^128+x^65+x^127+x^64+x^64+x == x^65+x^64+x^63+1 {&GF127{1 + 1<<63, 1}, &GF127{2, 1}, &GF127{0x8000000000000001, 3}}, } func TestMul(t *testing.T) { c := new(GF127) for _, tc := range testCasesMul { Mul(tc[0], tc[1], c) require.Equal(t, tc[2], c) } } var testCasesMul10 = [][2]*GF127{ {&GF127{123, 0}, &GF127{246, 0}}, {&GF127{maxUint64, 2}, &GF127{maxUint64 - 1, 5}}, {&GF127{0, maxUint64 >> 1}, &GF127{1 + 1<<63, maxUint64>>1 - 1}}, } func TestMul10(t *testing.T) { c := new(GF127) for _, tc := range testCasesMul10 { Mul10(tc[0], c) require.Equal(t, tc[1], c) } } var testCasesMul11 = [][2]*GF127{ {&GF127{123, 0}, &GF127{141, 0}}, {&GF127{maxUint64, 2}, &GF127{1, 7}}, {&GF127{0, maxUint64 >> 1}, &GF127{1 + 1<<63, 1}}, } func TestMul11(t *testing.T) { c := new(GF127) for _, tc := range testCasesMul11 { Mul11(tc[0], c) require.Equal(t, tc[1], c) } } var testCasesInv = [][2]*GF127{ {&GF127{1, 0}, &GF127{1, 0}}, {&GF127{3, 0}, &GF127{msb64, ^msb64}}, {&GF127{54321, 12345}, &GF127{8230555108620784737, 3929873967650665114}}, } func TestInv(t *testing.T) { var a, b, c = new(GF127), new(GF127), new(GF127) for _, tc := range testCasesInv { Inv(tc[0], c) require.Equal(t, tc[1], c) } for i := 0; i < 3; i++ { // 0 has no inverse if a = Random(); a.Equals(&GF127{0, 0}) { continue } Inv(a, b) Mul(a, b, c) require.Equal(t, &GF127{1, 0}, c) } }