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aes: Avoid illegal read and don't generate more key than we use.

This commit is contained in:
Alex Converse 2011-11-03 18:13:57 -07:00
parent 88b2436911
commit c9e5ac3380
1 changed files with 4 additions and 4 deletions
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8
libavutil/aes.c
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@ -222,11 +222,9 @@ int av_aes_init(AVAES *a, const uint8_t *key, int key_bits, int decrypt)
a->rounds = rounds;
memcpy(tk, key, KC * 4);
memcpy(a->round_key[0].u8, key, KC * 4);
for (t = 0; t < (rounds + 1) * 16;) {
memcpy(a->round_key[0].u8 + t, tk, KC * 4);
t += KC * 4;
for (t = KC * 4; t < (rounds + 1) * 16; t += KC * 4) {
for (i = 0; i < 4; i++)
tk[0][i] ^= sbox[tk[KC - 1][(i + 1) & 3]];
tk[0][0] ^= rcon[rconpointer++];
@ -239,6 +237,8 @@ int av_aes_init(AVAES *a, const uint8_t *key, int key_bits, int decrypt)
for (i = 0; i < 4; i++)
tk[j][i] ^= sbox[tk[j - 1][i]];
}
memcpy(a->round_key[0].u8 + t, tk, KC * 4);
}
if (decrypt) {