func (t *HashTest) SumDoesntAffectState() {
// Grab a test case.
cases := aes_testing.CmacCases()
AssertGt(len(cases), 10)
c := cases[10]
// Create a hash and feed it some of the test case's data.
h, err := cmac.New(c.Key)
AssertEq(nil, err)
AssertGt(len(c.Msg), 5)
_, err = h.Write(c.Msg[0:5])
AssertEq(nil, err)
// Call Sum.
AssertEq(16, len(h.Sum([]byte{})))
// Feed the rest of the data and call Sum again. We should get the correct
// result.
_, err = h.Write(c.Msg[5:])
AssertEq(nil, err)
ExpectThat(h.Sum([]byte{}), DeepEquals(c.Mac))
// Calling repeatedly should also work.
ExpectThat(h.Sum([]byte{}), DeepEquals(c.Mac))
ExpectThat(h.Sum([]byte{}), DeepEquals(c.Mac))
ExpectThat(h.Sum([]byte{}), DeepEquals(c.Mac))
}
func (t *HashTest) GeneratedTestCases() {
cases := aes_testing.CmacCases()
AssertGe(len(cases), 100)
for i, c := range cases {
mac := runCmac(c.Key, c.Msg)
ExpectThat(mac, DeepEquals(c.Mac), "Test case %d: %v", i, c)
}
}
func (t *HashTest) SumAppendsToSlice() {
// Grab a test case.
cases := aes_testing.CmacCases()
AssertGt(len(cases), 10)
c := cases[10]
// Create a hash and feed it the test case's data.
h, err := cmac.New(c.Key)
AssertEq(nil, err)
_, err = h.Write(c.Msg)
AssertEq(nil, err)
// Ask it to append to a non-empty slice.
prefix := []byte{0xde, 0xad, 0xbe, 0xef}
mac := h.Sum(prefix)
AssertEq(20, len(mac))
ExpectThat(mac[0:4], DeepEquals(prefix))
ExpectThat(mac[4:], DeepEquals(c.Mac))
}
func (t *HashTest) Reset() {
// Grab a test case.
cases := aes_testing.CmacCases()
AssertGt(len(cases), 10)
c := cases[10]
// Create a hash and feed it some data, then reset it.
h, err := cmac.New(c.Key)
AssertEq(nil, err)
_, err = h.Write([]byte{0xde, 0xad})
AssertEq(nil, err)
h.Reset()
// Feed the hash the test case's data and make sure the result is correct.
_, err = h.Write(c.Msg)
AssertEq(nil, err)
ExpectThat(h.Sum([]byte{}), DeepEquals(c.Mac))
}