1 C Used as temporaries by the AES macros
6 C Loop invariants used by AES_ROUND
12 C AES_LOAD(i, src, key, res)
15 ldub [$2 + 4*$1 + 1], TMP1
16 ldub [$2 + 4*$1 + 2], TMP2
20 ldub [$2 + 4*$1+3], TMP1
30 C AES_ROUND(i, a, b, c, d, key, res)
31 C Computes one word of the AES round
32 C FIXME: Could use registers pointing directly to the four tables
33 C FIXME: Needs better instruction scheduling, and perhaps more temporaries
34 C Alternatively, we can use a single table and some rotations
36 and $2, 0xff, TMP1 C 0
39 and TMP2, 0x3fc, TMP2 C 1
40 ld [T0 + TMP1], $7 C 0 E0
42 ld [T1 + TMP2], TMP2 C 1
43 and TMP1, 0x3fc, TMP1 C 2
44 xor $7, TMP2, $7 C 1 E1
46 ld [T2 + TMP1], TMP1 C 2
47 and TMP2, 0x3fc, TMP2 C 3
48 xor $7, TMP1, $7 C 2 E2
49 ld [$6 + 4*$1], TMP1 C 4
50 ld [T3 + TMP2], TMP2 C 3
51 xor $7, TMP1, $7 C 4 E4
52 xor $7, TMP2, $7 C 3 E3
55 C AES_FINAL_ROUND(i, T, a, b, c, d, key, dst)
56 C Compute one word in the final round function. Output is converted to
57 C octets and stored at dst. Relies on AES_SBOX being zero.
58 define(<AES_FINAL_ROUND>, <
62 and $3, 0xff, TMP1 C 0
64 ldub [T + TMP1], TMP1 C 0
65 and TMP2, 0xff, TMP2 C 1
66 xor TMP3, TMP1, TMP1 C 0
67 ldub [T + TMP2], TMP2 C 1
68 stb TMP1, [$8 + 4*$1] C 0 E0
71 and TMP1, 0xff, TMP1 C 2
72 xor TMP3, TMP2, TMP2 C 1
73 ldub [T + TMP1], TMP1 C 2
74 stb TMP2, [$8 + 4*$1 + 1] C 1 E1
77 ldub [T + TMP2], TMP2 C 3
78 xor TMP3, TMP1, TMP1 C 2
80 stb TMP1, [$8 + 4*$1 + 2] C 2 E2
81 xor TMP3, TMP2, TMP2 C 3
82 stb TMP2, [$8 + 4*$1 + 3] C 3 E3