// For example,
// ExpandWithTrustDomains({"spiffe://td1/ns/def/sa/def"}, {"td1", "td2"}) returns
//
//	{"spiffe://td1/ns/def/sa/def", "spiffe://td2/ns/def/sa/def"}.
//
// ExpandWithTrustDomains({"spiffe://td1/ns/def/sa/a", "spiffe://td1/ns/def/sa/b"}, {"td2"}) returns
//
//	{"spiffe://td1/ns/def/sa/a", "spiffe://td2/ns/def/sa/a", "spiffe://td1/ns/def/sa/b", "spiffe://td2/ns/def/sa/b"}.

	for i := 0; i < 256; i++ {
		s := uint32(sbox1[i])
		s9 := mul(s, 0x9)
		sb := mul(s, 0xb)
		sd := mul(s, 0xd)
		se := mul(s, 0xe)
		w := se<<24 | s9<<16 | sd<<8 | sb
		td := [][256]uint32{td0, td1, td2, td3}
		for j := 0; j < 4; j++ {
			if x := td[j][i]; x != w {
				t.Fatalf("td[%d][%d] = %#x, want %#x", j, i, x, w)
			}
			w = w<<24 | w>>8
		}
	}
}

// Test vectors are from FIPS 197: