Add 'twofactor/' from commit 'c999bf35b0e47de4f63d59abbe0d7efc76c13ced'

git-subtree-dir: twofactor
git-subtree-mainline: 4dc135cfe0
git-subtree-split: c999bf35b0

twofactor/oath_test.go

@@ -0,0 +1,30 @@
+package twofactor
+
+import (
+	"fmt"
+	"testing"
+)
+
+var sha1Hmac = []byte{
+	0x1f, 0x86, 0x98, 0x69, 0x0e,
+	0x02, 0xca, 0x16, 0x61, 0x85,
+	0x50, 0xef, 0x7f, 0x19, 0xda,
+	0x8e, 0x94, 0x5b, 0x55, 0x5a,
+}
+
+var truncExpect int64 = 0x50ef7f19
+
+// This test runs through the truncation example given in the RFC.
+func TestTruncate(t *testing.T) {
+	if result := truncate(sha1Hmac); result != truncExpect {
+		fmt.Printf("hotp: expected truncate -> %d, saw %d\n",
+			truncExpect, result)
+		t.FailNow()
+	}
+
+	sha1Hmac[19]++
+	if result := truncate(sha1Hmac); result == truncExpect {
+		fmt.Println("hotp: expected truncation to fail")
+		t.FailNow()
+	}
+}