优化

cipher/aria/aria.go

@@ -87,3 +87,98 @@ func (c *ariaCipher) Decrypt(dst, src []byte) {
 func (c *ariaCipher) rounds() int {
     return c.k/4 + 8
 }
+
+func (c *ariaCipher) cryptBlock(xk []uint32, dst, src []byte) {
+    n := c.rounds()
+
+    var p [16]byte
+
+    copy(p[:], src[:BlockSize])
+
+    for i := 1; i <= n-1; i++ {
+        if i&1 == 1 {
+            p = roundOdd(p, toBytes(xk[(i-1)*4:i*4]))
+        } else {
+            p = roundEven(p, toBytes(xk[(i-1)*4:i*4]))
+        }
+    }
+
+    p = xor(substitute2(xor(p, toBytes(xk[(n-1)*4:n*4]))), toBytes(xk[n*4:(n+1)*4]))
+
+    copy(dst[:BlockSize], p[:])
+}
+
+func (c *ariaCipher) expandKey(key []byte) {
+    n := c.rounds()
+
+    var kl, kr [16]byte
+
+    for i := 0; i < c.k; i++ {
+        if i < 16 {
+            kl[i] = key[i]
+        } else {
+            kr[i-16] = key[i]
+        }
+    }
+
+    var ck1, ck2, ck3 [16]byte
+
+    switch c.k {
+        case 128 / 8:
+            ck1 = c1
+            ck2 = c2
+            ck3 = c3
+        case 192 / 8:
+            ck1 = c2
+            ck2 = c3
+            ck3 = c1
+        case 256 / 8:
+            ck1 = c3
+            ck2 = c1
+            ck3 = c2
+    }
+
+    var w0, w1, w2, w3 [16]byte
+
+    w0 = kl // TODO: use kl instead of w0
+    w1 = xor(roundOdd(w0, ck1), kr)
+    w2 = xor(roundEven(w1, ck2), w0)
+    w3 = xor(roundOdd(w2, ck3), w1)
+
+    copyBytes(c.enc, xor(w0, rrot(w1, 19)))
+    copyBytes(c.enc[4:], xor(w1, rrot(w2, 19)))
+    copyBytes(c.enc[8:], xor(w2, rrot(w3, 19)))
+    copyBytes(c.enc[12:], xor(w3, rrot(w0, 19)))
+    copyBytes(c.enc[16:], xor(w0, rrot(w1, 31)))
+    copyBytes(c.enc[20:], xor(w1, rrot(w2, 31)))
+    copyBytes(c.enc[24:], xor(w2, rrot(w3, 31)))
+    copyBytes(c.enc[28:], xor(w3, rrot(w0, 31)))
+    copyBytes(c.enc[32:], xor(w0, lrot(w1, 61)))
+    copyBytes(c.enc[36:], xor(w1, lrot(w2, 61)))
+    copyBytes(c.enc[40:], xor(w2, lrot(w3, 61)))
+    copyBytes(c.enc[44:], xor(w3, lrot(w0, 61)))
+    copyBytes(c.enc[48:], xor(w0, lrot(w1, 31)))
+
+    if n > 12 {
+        copyBytes(c.enc[52:], xor(w1, lrot(w2, 31)))
+        copyBytes(c.enc[56:], xor(w2, lrot(w3, 31)))
+    }
+
+    if n > 14 {
+        copyBytes(c.enc[60:], xor(w3, lrot(w0, 31)))
+        copyBytes(c.enc[64:], xor(w0, lrot(w1, 19)))
+    }
+
+    copy(c.dec, c.enc[n*4:(n+1)*4])
+
+    for i := 1; i <= n-1; i++ {
+        var t [16]byte
+
+        t = toBytes(c.enc[(n-i)*4 : (n-i+1)*4])
+        t = diffuse(t)
+
+        copyBytes(c.dec[i*4:], t)
+    }
+
+    copy(c.dec[n*4:], c.enc[:4])
+}